From rosuav at gmail.com  Sun Jan  1 00:39:27 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 1 Jan 2017 16:39:27 +1100
Subject: Cleaning up conditionals
In-Reply-To: <004c01d263e3$5420fde0$27b23dae@sambora>
References: <CAPTjJmrm7qT-vN6KmfRT_3+1kajCPtuouVthVdu7rcV9w3xfeQ@mail.gmail.com>
 <004c01d263e3$5420fde0$27b23dae@sambora>
Message-ID: <CAPTjJmpMwLDMbz73otgKKw=ZM1=b0dZYirp7bECtZNLqSR1_rg@mail.gmail.com>

On Sun, Jan 1, 2017 at 2:58 PM, Deborah Swanson
<python at deborahswanson.net> wrote:
> I'm not sure I understand what you did here, at least not well enough to
> try it.
>
> What conditional can I do between the 2 rows of listings (the list names
> l1 and l2) that will give me which row has the value to copy from and
> which one is empty? I don't see how that can happen if you don't give
> the subscript [v] to each of l1 and l2, at a minimum. Unless python will
> distribute the [v] inside the preceding conditional?  Amazing, if true,
> but then we still need what the conditional is.
>
> And what is new_value? It could be either l1[v] or l2[v], depending on
> which one is not empty, and I don't see how the answer magically pops
> into it.  Not saying that it doesn't, but what should I call new_value
> in the real estate listings example I want to use it in?  There are no
> new values in this situation, only values that need to be copied into
> their empty counterparts in the other row.  (It may or may not help to
> read the synopsis of what I'm doing that I wrote up in my last post to
> Peter Otten.)

Start with this simple statement:

foo[2] = "spam"

Obviously this will subscript 'foo' with 2 and set that to the string
"spam". Easy. But instead of the word 'foo', we could use any
expression at all.

def return_foo():
    return foo

return_foo()[2] = "spam"

This is a little more surprising, but it does work.

And if you can use a function call to provide the list, you can use
anything else - even a conditional expression.

(foo if True else [])[2] = "spam"

It's perfectly legal, but I do NOT recommend it :)

ChrisA


From steve+python at pearwood.info  Sun Jan  1 01:24:58 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Sun, 01 Jan 2017 17:24:58 +1100
Subject: Cleaning up conditionals
References: <CAPTjJmrm7qT-vN6KmfRT_3+1kajCPtuouVthVdu7rcV9w3xfeQ@mail.gmail.com>
 <004c01d263e3$5420fde0$27b23dae@sambora>
 <mailman.99.1483243084.2395.python-list@python.org>
Message-ID: <5868a0bc$0$1622$c3e8da3$5496439d@news.astraweb.com>

On Sun, 1 Jan 2017 02:58 pm, Deborah Swanson wrote:

>> It's possible to select either l1 or l2 using an expression,
>> and then subscript that with [v]. However, this does not
>> usually make for readable code, so I don't recommend it.
>> 
>> (l1 if whatever else l2)[v] = new_value
>> 
>> ChrisA
> 
> I'm not sure I understand what you did here, at least not well enough to
> try it.


The evolution of a Python programmer :-)


(1) Step One: the naive code.

if condition:
    l1[v] = new_value
else:
    l2[v] = new_value


(2) Step Two: add a temporary variable to avoid repeating the assignment

if condition:
    temp = l1
else:
    temp = l2
temp[v] = new_value


(3) Step Three: change the if...else statement to an expression

temp = l1 if condition else l2
temp[v] = new_value


(4) Step Four: no need for the temporary variable

(l1 if condition else l2)[v] = new_value





-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From jussi.piitulainen at helsinki.fi  Sun Jan  1 02:44:30 2017
From: jussi.piitulainen at helsinki.fi (Jussi Piitulainen)
Date: Sun, 01 Jan 2017 09:44:30 +0200
Subject: Cleaning up conditionals
References: <lf57f6gkqo3.fsf@ling.helsinki.fi>
 <002001d263b1$a9e3de50$27b23dae@sambora>
 <mailman.92.1483221761.2395.python-list@python.org>
Message-ID: <lf5zijbp6ld.fsf@ling.helsinki.fi>

Deborah Swanson writes:

> Jussi Piitulainen wrote:
>> Sent: Saturday, December 31, 2016 8:30 AM
>> Deborah Swanson writes:
>> 
>> > Is it possible to use some version of the "a = expression1 if
>> > condition else expression2" syntax with an elif? And for
>> > expression1 and expression2 to be single statements?  That's the
>> > kind of shortcutting I'd like to do, and it seems like python might
>> > be able to do something like this.
>> 
>> I missed this question when I read the thread earlier. The 
>> answer is simply to make expression2 be another conditional 
>> expression. I tend to write the whole chain in parentheses. 
>> This allows multi-line layouts like the following alternatives:
>> 
>> a = ( first if len(first) > 0
>>       else second if len(second) > 0
>>       else make_stuff_up() )
>> 
>> a = ( first if len(first) > 0 else
>>       second if len(second) > 0 else
>>       make_stuff_up() )
>> 
>> Expression1 and expression2 cannot be statements. Python 
>> makes a formal distinction between statements that have an 
>> effect and expressions that have a value. All components of a 
>> conditional expression must be expressions. A function call 
>> can behave either way but I think it good style that the 
>> calls in expresions return values.
>
> While I'm sure these terniaries will be useful for future problems, I
> couldn't make the second one work for my current problem.

(Note that those two things are just different layouts for the exact
same conditional expression.)

> I got as far as:
>
> a = l1[v] if len(l1[v] > 0 else 
>     l2[v] if len(l2[v] > 0 else

(Parentheses needed, otherwise the first line is expected to be a whole
statement and then the unfinished expression in it is considered
malformed.)

> And didn't finish it because I couldn't see what a should be. I want
> it to be l2[v] if the first clause is true, and l1[v] if the second.
> If I was computing a value, this would work beautifully, but I don't
> see how it can if I'm choosing a list element to assign to. Maybe I
> just can't see it.

Do you here mean condition when you say clause? Then, if the first
condition is true, any other condition is not considered at all. When
you come to the final else-branch, you know that all conditions in the
chain were false.

I thought you originally wanted to keep l1[v] if it was non-empty, which
is what the code here says, but this time your prose seems different.
Anyhow, since you want a value when all conditions in the chain of
conditions are false, you want a value to use when the field is empty in
both records. To change nothing, store the old empty value back; or you
can supply your own default here.

With your particular conditions of non-emptiness, which is taken to be
truth, you can achieve variations of this result with any of the
following statements:

w = ( l1[v] if len(l1[v]) > 0 else
      l2[v] if len(l2[v]) > 0 else
      l1[v] )

x = l1[v] if l1[v] else l2[v] if l2[v] else l1[v]

y = l1[v] or l2[v] or l1[v]

z = l1[v] or l2[v]

The last one, which I originally suggested (and still prefer when
otherwise appropriate), is subtly different from the others. That
difference should be irrelevant.


From jussi.piitulainen at helsinki.fi  Sun Jan  1 03:01:14 2017
From: jussi.piitulainen at helsinki.fi (Jussi Piitulainen)
Date: Sun, 01 Jan 2017 10:01:14 +0200
Subject: Cleaning up conditionals
References: <CAPTjJmrm7qT-vN6KmfRT_3+1kajCPtuouVthVdu7rcV9w3xfeQ@mail.gmail.com>
 <004c01d263e3$5420fde0$27b23dae@sambora>
 <mailman.99.1483243084.2395.python-list@python.org>
 <5868a0bc$0$1622$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <lf5vatzp5th.fsf@ling.helsinki.fi>

Steve D'Aprano writes:

> On Sun, 1 Jan 2017 02:58 pm, Deborah Swanson wrote:
>
>>> It's possible to select either l1 or l2 using an expression,
>>> and then subscript that with [v]. However, this does not
>>> usually make for readable code, so I don't recommend it.
>>> 
>>> (l1 if whatever else l2)[v] = new_value
>>> 
>>> ChrisA
>> 
>> I'm not sure I understand what you did here, at least not well enough
>> to try it.
>
>
> The evolution of a Python programmer :-)
>
>
> (1) Step One: the naive code.
>
> if condition:
>     l1[v] = new_value
> else:
>     l2[v] = new_value
>
>
> (2) Step Two: add a temporary variable to avoid repeating the
> assignment
>
> if condition:
>     temp = l1
> else:
>     temp = l2
> temp[v] = new_value
>
>
> (3) Step Three: change the if...else statement to an expression
>
> temp = l1 if condition else l2
> temp[v] = new_value
>
>
> (4) Step Four: no need for the temporary variable
>
> (l1 if condition else l2)[v] = new_value

(l1 if bool(l1[v]) < bool(l2[v]) else
 l2 if bool(l1[v]) > bool(l2[v]) else
 l1)[v] = (l2 if bool(l1[v]) < bool(l2[v]) else
           l1 if bool(l1[v]) > bool(l2[v]) else
           l1)[v]

Merry new year :)


From python at deborahswanson.net  Sun Jan  1 05:09:33 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sun, 1 Jan 2017 02:09:33 -0800
Subject: Cleaning up conditionals
In-Reply-To: <lf5vatzp5th.fsf@ling.helsinki.fi>
Message-ID: <001101d26417$26d40420$27b23dae@sambora>

Sorry guys. I've read all your responses and I kind of get their general
drift, but I'm about four sheets to the wind right now, and no way would
I make it more than a step or two in playing around with these things
and trying to get my head around them before it would all descend into a
cacaphony of gibberish.

Python really is a thing of beauty in a class all its own. I've been
doing computers since 1972. I started out doing machine code on IBM's
7090 octal machine, then I stepped up to assembler on the hexadecimal
IBM 360/40, a mainframe that needed a machine room the size of two
classrooms to house it and all its peripherals. (Disk drives were the
size of huge round birthday cakes, tape drives were each housed in 4' x
4' cabinets, and the printers had to go out in the hallway because they
couldn't even fit in the same room with the computer.) The first high
level language I stepped up to was PL/1, a real behemoth of its time, a
one-foot-in-front-of-the-other procedural languaage from its insides
out, and a full set of all its manuals filled a small library. Funny
though, for all its "primitivity" compared to modern languages, we did
artificial intelligence, symbolic calculus (no numbers, just complex
integrals and differentials of function names, with x, y and z for
arguments) and weather modelling with it. And I've learned smatterings
of Java, C and C++, but nowhere have I seen the kinds of magic that can
be done with python. I've been exposed to applying functions to a list
of values, so I fully believe that what you present is valid python and
it works. I just don't fully understand how and will have to work with
it.

So, in the morning I'll scrape my braincells together and work with what
you've given me, and see if I can understand it and make your examples
work. Well worth the detour from finding the perfect place to move to (a
project that has become a little less urgent due to recent events). So
stay tuned. I'm not ignoring you, I just need a good night's sleep and
then maybe a good long while before I have anything to show for doing
anything with this, or even intelligent questions.  Thank you all in
advance, I'm expecting to learn a lot from this little exercise.



From rustompmody at gmail.com  Sun Jan  1 09:20:47 2017
From: rustompmody at gmail.com (Rustom Mody)
Date: Sun, 1 Jan 2017 06:20:47 -0800 (PST)
Subject: Cleaning up conditionals
In-Reply-To: <mailman.102.1483265342.2395.python-list@python.org>
References: <lf5vatzp5th.fsf@ling.helsinki.fi>
 <001101d26417$26d40420$27b23dae@sambora>
 <mailman.102.1483265342.2395.python-list@python.org>
Message-ID: <8f9a3558-add3-4e4b-9470-4c93881b185d@googlegroups.com>

On Sunday, January 1, 2017 at 3:39:14 PM UTC+5:30, Deborah Swanson wrote:
> Sorry guys. I've read all your responses and I kind of get their general
> drift, but I'm about four sheets to the wind right now, and no way would
> I make it more than a step or two in playing around with these things
> and trying to get my head around them before it would all descend into a
> cacaphony of gibberish.

Its true that in most programming languages one is likely to see,
a conditional (if) statement is likely harder to grok than a conditional 
expression ie if the expression is allowed at all!!
Just as recursion is supposedly harder than repetition,
List comprehensions harder than for-loops
etc etc

This is true culturally and historically but not necessarily.

>From the more conceptual viewpoint they are duals; see table at
http://blog.languager.org/2016/01/primacy.html#expstat

Of course if one has grown up with assignment (and even more so the print 
statement) being (imagined to be) easy and natural and obvious, this logically 
unnecessary but culturally inevitable sense of difficulty will be there... unfortunately.

tl;dr Above is unlikely to help reduce the confusion.  The essential ideas 
behind the jargon called 'functional programming' would go a good way towards that.


From rustompmody at gmail.com  Sun Jan  1 09:32:32 2017
From: rustompmody at gmail.com (Rustom Mody)
Date: Sun, 1 Jan 2017 06:32:32 -0800 (PST)
Subject: Cleaning up conditionals
In-Reply-To: <8f9a3558-add3-4e4b-9470-4c93881b185d@googlegroups.com>
References: <lf5vatzp5th.fsf@ling.helsinki.fi>
 <001101d26417$26d40420$27b23dae@sambora>
 <mailman.102.1483265342.2395.python-list@python.org>
 <8f9a3558-add3-4e4b-9470-4c93881b185d@googlegroups.com>
Message-ID: <54b5f5ab-5af7-4e9d-b056-8bdebf4193b9@googlegroups.com>

On Sunday, January 1, 2017 at 7:51:12 PM UTC+5:30, Rustom Mody wrote:
> On Sunday, January 1, 2017 at 3:39:14 PM UTC+5:30, Deborah Swanson wrote:
> > Sorry guys. I've read all your responses and I kind of get their general
> > drift, but I'm about four sheets to the wind right now, and no way would
> > I make it more than a step or two in playing around with these things
> > and trying to get my head around them before it would all descend into a
> > cacaphony of gibberish.
> 
> Its true that in most programming languages one is likely to see,
> a conditional (if) statement is likely harder to grok than a conditional 
> expression ie if the expression is allowed at all!!

Er... Meant the other way round!


From grant.b.edwards at gmail.com  Sun Jan  1 12:30:11 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Sun, 1 Jan 2017 17:30:11 +0000 (UTC)
Subject: learning and experimenting python.
References: <6886d439-751c-42d2-adf2-fbf494221d48@googlegroups.com>
 <o47q7t$4jq$1@dont-email.me>
 <58678152$0$1622$c3e8da3$5496439d@news.astraweb.com>
 <d5a48cd6-fd0e-45eb-bac6-0bf7dc131250@googlegroups.com>
 <CALwzid=98ggNQiLNe0sVMbxN2wQ-zGecFvQf-DZ4_JRTjNZWuQ@mail.gmail.com>
Message-ID: <o4beb3$8h4$1@blaine.gmane.org>

On 2016-12-31, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> On Dec 31, 2016 3:12 AM, <einstein1410 at gmail.com> wrote:
>
> That's true.
>
> Please include quoted context in your replies. I have no idea who or what
> you're responding to.

I'd just like to thank everybody for replying to einstein1410's posts
so that those of us who have plonked posts from googlegroups don't
miss out on his/her valuable contributions.

--
Grant




From python at deborahswanson.net  Sun Jan  1 17:58:40 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sun, 1 Jan 2017 14:58:40 -0800
Subject: Cleaning up conditionals
In-Reply-To: <5868a0bc$0$1622$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <002001d26482$98ad3560$27b23dae@sambora>

Steve D'Aprano wrote
> Sent: Saturday, December 31, 2016 10:25 PM
> 
> On Sun, 1 Jan 2017 02:58 pm, Deborah Swanson wrote:
> 
> >> It's possible to select either l1 or l2 using an 
> expression, and then 
> >> subscript that with [v]. However, this does not usually make for 
> >> readable code, so I don't recommend it.
> >> 
> >> (l1 if whatever else l2)[v] = new_value
> >> 
> >> ChrisA
> > 
> > I'm not sure I understand what you did here, at least not 
> well enough 
> > to try it.
> 
> 
> The evolution of a Python programmer :-)
 
;)

> (1) Step One: the naive code.
> 
> if condition:
>     l1[v] = new_value
> else:
>     l2[v] = new_value
> 
> 
> (2) Step Two: add a temporary variable to avoid repeating the 
> assignment
> 
> if condition:
>     temp = l1
> else:
>     temp = l2
> temp[v] = new_value
> 
> 
> (3) Step Three: change the if...else statement to an expression
> 
> temp = l1 if condition else l2
> temp[v] = new_value
> 
> 
> (4) Step Four: no need for the temporary variable
> 
> (l1 if condition else l2)[v] = new_value
> 
> 
> 
> 
> 
> -- 
> Steve
> "Cheer up," they said, "things could be worse." So I cheered 
> up, and sure enough, things got worse.

This is a very nice explanation of why Chris' statement is valid python
and I completely understand it, though I didn't see how it worked when I
wrote the message you're quoting. Unfortunately this isn't the part that
still gives me trouble.

The real troublemaker here for me, is what should new_value be defined
to be?

It will be either l1[v] or l2[v], depending on which one is non-empty.
But I still don't see any way this terniary assigns the correct value to
the correct field. 

If we back up to your Step One, it's clear that this dilemma is present
from the get-go.

(1) Step One: the naive code.

if condition:
    l1[v] = new_value
else:
    l2[v] = new_value

Here the assumption is that new_value is the same for both if and else.
But it isn't. Here's the actual desired outcome:

if condition:
    l1[v] = l2[v]
else:
    l2[v] = l1[v]

That's why I've been saying that 

	(l1 if whatever else l2)[v] = new_value

works beautifully if you are computing a value, but it doesn't work at
all if you're selecting a row to copy the field value from the other row
to.



From python at deborahswanson.net  Sun Jan  1 18:12:24 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sun, 1 Jan 2017 15:12:24 -0800
Subject: Cleaning up conditionals
In-Reply-To: <CAPTjJmpMwLDMbz73otgKKw=ZM1=b0dZYirp7bECtZNLqSR1_rg@mail.gmail.com>
Message-ID: <002301d26484$83cce670$27b23dae@sambora>

Chris Angelico wrote on Saturday, December 31, 2016 9:39 PM
> 
> On Sun, Jan 1, 2017 at 2:58 PM, Deborah Swanson 
> <python at deborahswanson.net> wrote:
> > I'm not sure I understand what you did here, at least not 
> well enough 
> > to try it.
> >
> > What conditional can I do between the 2 rows of listings (the list 
> > names l1 and l2) that will give me which row has the value to copy 
> > from and which one is empty? I don't see how that can happen if you 
> > don't give the subscript [v] to each of l1 and l2, at a minimum. 
> > Unless python will distribute the [v] inside the preceding 
> > conditional?  Amazing, if true, but then we still need what the 
> > conditional is.
> >
> > And what is new_value? It could be either l1[v] or l2[v], 
> depending on 
> > which one is not empty, and I don't see how the answer 
> magically pops 
> > into it.  Not saying that it doesn't, but what should I 
> call new_value 
> > in the real estate listings example I want to use it in?  
> There are no 
> > new values in this situation, only values that need to be 
> copied into 
> > their empty counterparts in the other row.  (It may or may 
> not help to 
> > read the synopsis of what I'm doing that I wrote up in my 
> last post to 
> > Peter Otten.)
> 
> Start with this simple statement:
> 
> foo[2] = "spam"
> 
> Obviously this will subscript 'foo' with 2 and set that to 
> the string "spam". Easy. But instead of the word 'foo', we 
> could use any expression at all.
> 
> def return_foo():
>     return foo
> 
> return_foo()[2] = "spam"
> 
> This is a little more surprising, but it does work.
> 
> And if you can use a function call to provide the list, you 
> can use anything else - even a conditional expression.
> 
> (foo if True else [])[2] = "spam"
> 
> It's perfectly legal, but I do NOT recommend it :)
> 
> ChrisA

I see what you're doing here and I have applied functions to values and
variables before, so I know it's legal and that it works. Thanks for
giving me this other way that the same principle can be used with
conditionals.

I know I keep repeating myself, but aside from the advisability (or not)
of using this form, the real problem is that "spam" will only be the
right answer in one of the two cases.  The job of this conditional is to
choose which value to put into which field.



From python at deborahswanson.net  Sun Jan  1 18:50:25 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sun, 1 Jan 2017 15:50:25 -0800
Subject: Cleaning up conditionals
In-Reply-To: <lf5zijbp6ld.fsf@ling.helsinki.fi>
Message-ID: <002801d26489$d3073dd0$27b23dae@sambora>



> -----Original Message-----
> From: Python-list 
> [mailto:python-list-bounces+python=deborahswanson.net at python.o
> rg] On Behalf Of Jussi Piitulainen
> Sent: Saturday, December 31, 2016 11:45 PM
> To: python-list at python.org
> Subject: Re: Cleaning up conditionals
> Importance: High
> 
> 
> Deborah Swanson writes:
> 
> > Jussi Piitulainen wrote:
> >> Sent: Saturday, December 31, 2016 8:30 AM
> >> Deborah Swanson writes:
> >> 
> >> > Is it possible to use some version of the "a = expression1 if 
> >> > condition else expression2" syntax with an elif? And for 
> >> > expression1 and expression2 to be single statements?  That's the 
> >> > kind of shortcutting I'd like to do, and it seems like 
> python might 
> >> > be able to do something like this.
> >> 
> >> I missed this question when I read the thread earlier. The
> >> answer is simply to make expression2 be another conditional 
> >> expression. I tend to write the whole chain in parentheses. 
> >> This allows multi-line layouts like the following alternatives:
> >> 
> >> a = ( first if len(first) > 0
> >>       else second if len(second) > 0
> >>       else make_stuff_up() )
> >> 
> >> a = ( first if len(first) > 0 else
> >>       second if len(second) > 0 else
> >>       make_stuff_up() )
> >> 
> >> Expression1 and expression2 cannot be statements. Python
> >> makes a formal distinction between statements that have an 
> >> effect and expressions that have a value. All components of a 
> >> conditional expression must be expressions. A function call 
> >> can behave either way but I think it good style that the 
> >> calls in expresions return values.
> >
> > While I'm sure these terniaries will be useful for future 
> problems, I 
> > couldn't make the second one work for my current problem.
> 
> (Note that those two things are just different layouts for 
> the exact same conditional expression.)
> 
> > I got as far as:
> >
> > a = l1[v] if len(l1[v] > 0 else 
> >     l2[v] if len(l2[v] > 0 else
> 
> (Parentheses needed, otherwise the first line is expected to 
> be a whole statement and then the unfinished expression in it 
> is considered
> malformed.)

Thanks, I missed that. (Never ran the code because I couldn't finish
it.)
 
> > And didn't finish it because I couldn't see what a should 
> be. I want 
> > it to be l2[v] if the first clause is true, and l1[v] if 
> the second. 
> > If I was computing a value, this would work beautifully, 
> but I don't 
> > see how it can if I'm choosing a list element to assign to. Maybe I 
> > just can't see it.
> 
> Do you here mean condition when you say clause? Then, if the 
> first condition is true, any other condition is not 
> considered at all. When you come to the final else-branch, 
> you know that all conditions in the chain were false.

This is fine, in general we wouldn't know if either l1[v] or l2[v] are
non-empty, and it would be possible that both are empty. But this
function is only called if they're not equal, which means one of them
could be empty, or that the two fields are both non-empty and different
from each other (my second test).

So I had two problems implementing this code. The first one was that the
final else was a dead end and I didn't see what to replace it with
(though I can see now what it should be). But the biggest problem is
what a is.  It should be either the location l1[v] or the location
l2[v], but by making it a scalar, a is not in either row. It's just a
disconnected variable, so the statement doesn't assign anything to a
field in either row.

> I thought you originally wanted to keep l1[v] if it was 
> non-empty, which is what the code here says, but this time 
> your prose seems different. Anyhow, since you want a value 
> when all conditions in the chain of conditions are false, you 
> want a value to use when the field is empty in both records. 
> To change nothing, store the old empty value back; or you can 
> supply your own default here.
> 
> With your particular conditions of non-emptiness, which is 
> taken to be truth, you can achieve variations of this result 
> with any of the following statements:
> 
> w = ( l1[v] if len(l1[v]) > 0 else
>       l2[v] if len(l2[v]) > 0 else
>       l1[v] )
> 
> x = l1[v] if l1[v] else l2[v] if l2[v] else l1[v]
> 
> y = l1[v] or l2[v] or l1[v]
> 
> z = l1[v] or l2[v]
> 
> The last one, which I originally suggested (and still prefer 
> when otherwise appropriate), is subtly different from the 
> others. That difference should be irrelevant.

I agree, if the goal was to capture one of the field values in a scalar
value.

Maybe it would help if I give a couple rows of (made up) data to show
what I mean (first row is field titles):

......Description		Date		State/co	Kind
Notes
l1	2 br, Elk Plains	12-26		WA/pi		house
garage, w/d
l2	2 br, Elk Plains	12-29

In this case, I want to copy the values from l1 to l2.

Or I could have, say, if I didn't see the one on 12-26 until after
12-29: 
l1	2 br, Elk Plains	12-26		
l2	2 br, Elk Plains	12-29		WA/pi		house
garage, w/d

In this case, I want to copy the values from l2 to l1.

While I still don't see how any of your versions would solve this
problem, it remains true that your form would be excellent for assigning
to a scalar variable, which is what they claim to do.





From greg.ewing at canterbury.ac.nz  Sun Jan  1 18:52:12 2017
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Mon, 02 Jan 2017 12:52:12 +1300
Subject: Cleaning up conditionals
In-Reply-To: <mailman.98.1483241325.2395.python-list@python.org>
References: <o48m3v$tk1$1@blaine.gmane.org>
 <002101d263b6$3ae79960$27b23dae@sambora>
 <aatg6clp40g9qclbo29rdufc6tb0pjkgd9@4ax.com>
 <mailman.98.1483241325.2395.python-list@python.org>
Message-ID: <ectj1cF4d2qU1@mid.individual.net>

> On Sat, 31 Dec 2016 14:35:46 -0800, "Deborah Swanson"
> <python at deborahswanson.net> declaimed the following:
> 
>>       if len(l1[v]) == 0 and len(l2[v]) != 0:
>>           l1[v] = l2[v]
>>       elif len(l2[v]) == 0 and len(l1[v]) != 0:
>>           l2[v] = l1[v]
>>       elif l1[v] != l2[v]:
>>           ret += ", " + labels[v] + " diff" if len(ret) > 0 else 
>>           labels[v] + " diff"

There are a couple of things I would probably do
with this:

1. Drop the len() calls and just test the lists directly.

2. Eliminate some redundant indexing operations.

    l1v = l1[v]
    l2v = l2[v]
    if l2v and not l1v:
       l1[v] = l2v
    elif l1v and not l2v:
       l2[v] = l1v
    elif l1v != l2v:
       ret += ", " + labels[v] + " diff" if len(ret) > 0 else
       labels[v] + " diff"

Jussi Piitulainen wrote:
 > (l1 if bool(l1[v]) < bool(l2[v]) else
 >  l2 if bool(l1[v]) > bool(l2[v]) else
 >  l1)[v] = (l2 if bool(l1[v]) < bool(l2[v]) else
 >            l1 if bool(l1[v]) > bool(l2[v]) else
 >            l1)[v]
 >

If you're aiming for readability, that's *not* the way
to go! Not every 7-line function needs to be written
on one line. :-)

-- 
Greg


From bc at freeuk.com  Sun Jan  1 18:56:25 2017
From: bc at freeuk.com (BartC)
Date: Sun, 1 Jan 2017 23:56:25 +0000
Subject: Cleaning up conditionals
In-Reply-To: <54b5f5ab-5af7-4e9d-b056-8bdebf4193b9@googlegroups.com>
References: <lf5vatzp5th.fsf@ling.helsinki.fi>
 <001101d26417$26d40420$27b23dae@sambora>
 <mailman.102.1483265342.2395.python-list@python.org>
 <8f9a3558-add3-4e4b-9470-4c93881b185d@googlegroups.com>
 <54b5f5ab-5af7-4e9d-b056-8bdebf4193b9@googlegroups.com>
Message-ID: <o4c4sf$jre$2@dont-email.me>

On 01/01/2017 14:32, Rustom Mody wrote:
> On Sunday, January 1, 2017 at 7:51:12 PM UTC+5:30, Rustom Mody wrote:
>> On Sunday, January 1, 2017 at 3:39:14 PM UTC+5:30, Deborah Swanson wrote:
>>> Sorry guys. I've read all your responses and I kind of get their general
>>> drift, but I'm about four sheets to the wind right now, and no way would
>>> I make it more than a step or two in playing around with these things
>>> and trying to get my head around them before it would all descend into a
>>> cacaphony of gibberish.
>>
>> Its true that in most programming languages one is likely to see,
>> a conditional (if) statement is likely harder to grok than a conditional
>> expression ie if the expression is allowed at all!!
>
> Er... Meant the other way round!

Python's version is certainly a little harder to understand!

What is it again:  X if C else Y ?

Here, if C is false, then only Y is evaluated, even though the first 
thing encountered is X! More than a little unintuitive.

-- 
Bartc




From tjreedy at udel.edu  Sun Jan  1 21:25:25 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Sun, 1 Jan 2017 21:25:25 -0500
Subject: New re feature in 3.6: local flags and example use
Message-ID: <o4cdmh$a60$1@blaine.gmane.org>

The re module defines several flags that affect the compilation of a 
pattern string.  For instance, re.I == re.IGNORECASE results in 
case-insensitive matching.

But what if you want part of a pattern to be case sensitive and part 
not?  For instance, the IDLE colorizer needs to match keywords and 
builtin names with their exact case: 'if' is a keywork, 'If', 'iF', and 
'IF' are not.  However, case does not matter string prefixes: 'fr', 
'fR', 'Fr', and 'FR' are all the same to the tokenizer.  So the string 
prefix part of the colorize pattern was recently upgraded to

r"(\br|R|u|U|f|F|fr|Fr|fR|FR|rf|rF|Rf|RF|b|B|br|Br|bR|BR|rb|rB|Rb|RB)?"

3.6 added syntax for 'local flags'.
'''
(?imsx-imsx:...)

     (Zero or more letters from the set 'i', 'm', 's', 'x', optionally 
followed by '-' followed by one or more letters from the same set.) The 
letters set or removes the corresponding flags: re.I (ignore case), re.M 
(multi-line), re.S (dot matches all), and re.X (verbose), for the part 
of the expression. (The flags are described in Module Contents.)
'''
Here is the replacement for the above, curtesy of Serhiy Storchaka.

r"(?i:\br|u|f|fr|rf|b|br|rb)?"

-- 
Terry Jan Reedy



From python at deborahswanson.net  Sun Jan  1 21:30:03 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sun, 1 Jan 2017 18:30:03 -0800
Subject: Cleaning up conditionals
In-Reply-To: <k0dj6cdj54iq1negtrq583ujus1e7svsfl@4ax.com>
Message-ID: <002b01d264a0$2063c4c0$27b23dae@sambora>

Dennis Lee Bieber wrote, on Sunday, January 01, 2017 6:07 PM
> 
> On Sun, 1 Jan 2017 15:50:25 -0800, "Deborah Swanson" 
> <python at deborahswanson.net> declaimed the following:
> 
> >Maybe it would help if I give a couple rows of (made up) 
> data to show 
> >what I mean (first row is field titles):
> >
> >......Description		Date		State/co	Kind
> >Notes
> >l1	2 br, Elk Plains	12-26		WA/pi		house
> >garage, w/d
> >l2	2 br, Elk Plains	12-29
> >
> >In this case, I want to copy the values from l1 to l2.
> >
> >Or I could have, say, if I didn't see the one on 12-26 until after
> >12-29: 
> >l1	2 br, Elk Plains	12-26		
> >l2	2 br, Elk Plains	12-29		WA/pi		house
> >garage, w/d
> >
> >In this case, I want to copy the values from l2 to l1.
> >
> 
> 	And what happens if the data (where ever you get it 
> from to be in one
> file) looks like
> 
> l1	2 br, Elk Plains	12-26		WA/pi
> l2	2 br, Elk Plains	12-29				
> 	house garage, w/d
> 
> 	As I understand your logic, you intend to make the two 
> entries identical EXCEPT for the DATE. What purpose does this 
> duplication serve? Or, put another way -- why is preserving 
> distinctive dates important while everything else is subject 
> to being blended.

Yes, that's exactly what I'm doing in this bit of code, making all the
listings that are identical except for the date be identical except for
the date. You may or may not have tried this approach to finding the
ideal house, but this is my third house hunt, using essentially the same
approach, but in a different language each time. (Python is by far the
best version. A dictionary with city names as keys, and several data
items as values has literally cut the task in half.) 

The usefulness of keeping track of these duplicate listings is history
of the rental being offered. In a real estate market that's on fire like
we have here in the Pacific NW, any house that's relisted more than a
couple times has something wrong with it or it would have been snatched
up, or it's way out in the boonies. In any event, if I do decide to look
at it, my bargaining position is improved by knowing that they've been
trying to rent it for a long friggin time. When I find a new one that
looks promising, I may reject it if I see that it's been on the market a
long time (and I have another bit of code that tells me that instantly).
You can design your project any way you want to!
 
> 	I still get this feeling you should have master file, 
> regardless of whether fields are empty, and treat subsequent 
> data as updates to the master file -- not as some confusing 
> single file with some sort of duplicate contents.
> -- 
> 	Wulfraed                 Dennis Lee Bieber         AF6VN
>     wlfraed at ix.netcom.com    HTTP://wlfraed.home.netcom.com/

You're certainly entitled to your opinion, but my method is time-tested
for my purposes.



From ian.g.kelly at gmail.com  Sun Jan  1 23:45:26 2017
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Sun, 1 Jan 2017 22:45:26 -0600
Subject: New re feature in 3.6: local flags and example use
In-Reply-To: <o4cdmh$a60$1@blaine.gmane.org>
References: <o4cdmh$a60$1@blaine.gmane.org>
Message-ID: <CALwzidn+EpJ94ELZuLguaYheqAbrY6zZy6YWQd13Whp+iGbTpA@mail.gmail.com>

On Sun, Jan 1, 2017 at 8:25 PM, Terry Reedy <tjreedy at udel.edu> wrote:
\> 3.6 added syntax for 'local flags'.
> '''
> (?imsx-imsx:...)
>
>     (Zero or more letters from the set 'i', 'm', 's', 'x', optionally
> followed by '-' followed by one or more letters from the same set.) The
> letters set or removes the corresponding flags: re.I (ignore case), re.M
> (multi-line), re.S (dot matches all), and re.X (verbose), for the part of
> the expression. (The flags are described in Module Contents.)
> '''
> Here is the replacement for the above, curtesy of Serhiy Storchaka.
>
> r"(?i:\br|u|f|fr|rf|b|br|rb)?"

What is the difference between the letters before the hyphen and those
after? I guess that placing the letter before means to set the flag
and after means to unset it, but it's not clear from the
documentation.


From best_lay at yahoo.com  Mon Jan  2 01:06:50 2017
From: best_lay at yahoo.com (Wildman)
Date: Mon, 02 Jan 2017 00:06:50 -0600
Subject: learning and experimenting python.
References: <6886d439-751c-42d2-adf2-fbf494221d48@googlegroups.com>
 <o47q7t$4jq$1@dont-email.me>
 <58678152$0$1622$c3e8da3$5496439d@news.astraweb.com>
 <d5a48cd6-fd0e-45eb-bac6-0bf7dc131250@googlegroups.com>
 <CALwzid=98ggNQiLNe0sVMbxN2wQ-zGecFvQf-DZ4_JRTjNZWuQ@mail.gmail.com>
 <o4beb3$8h4$1@blaine.gmane.org>
 <mailman.104.1483291835.2395.python-list@python.org>
 <c4d371a9-0d00-4a98-8daf-894811a9b72d@googlegroups.com>
Message-ID: <W-GdnbGl-7FncPTFnZ2dnUU7-IGdnZ2d@giganews.com>

On Sun, 01 Jan 2017 10:41:22 -0800, einstein1410 wrote:

> What contribution I had made especially valuable?

Ask your mommy what sarcasm means.

-- 
<Wildman> GNU/Linux user #557453
The cow died so I don't need your bull!


From ian.g.kelly at gmail.com  Mon Jan  2 01:15:58 2017
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Mon, 2 Jan 2017 00:15:58 -0600
Subject: learning and experimenting python.
In-Reply-To: <o4beb3$8h4$1@blaine.gmane.org>
References: <6886d439-751c-42d2-adf2-fbf494221d48@googlegroups.com>
 <o47q7t$4jq$1@dont-email.me>
 <58678152$0$1622$c3e8da3$5496439d@news.astraweb.com>
 <d5a48cd6-fd0e-45eb-bac6-0bf7dc131250@googlegroups.com>
 <CALwzid=98ggNQiLNe0sVMbxN2wQ-zGecFvQf-DZ4_JRTjNZWuQ@mail.gmail.com>
 <o4beb3$8h4$1@blaine.gmane.org>
Message-ID: <CALwzid=prEqEzHu=0=HAXt-EFCPqd+q6xmX+-9ti=zTHR8Ru6Q@mail.gmail.com>

On Sun, Jan 1, 2017 at 11:30 AM, Grant Edwards
<grant.b.edwards at gmail.com> wrote:
> On 2016-12-31, Ian Kelly <ian.g.kelly at gmail.com> wrote:
>> On Dec 31, 2016 3:12 AM, <einstein1410 at gmail.com> wrote:
>>
>> That's true.
>>
>> Please include quoted context in your replies. I have no idea who or what
>> you're responding to.
>
> I'd just like to thank everybody for replying to einstein1410's posts
> so that those of us who have plonked posts from googlegroups don't
> miss out on his/her valuable contributions.

If you want your own decision to cease interacting with him to be
forced on everybody here then I suggest you petition the group admins
to ban him rather than merely plonk him yourself.

Since they're unlikely to do that however, I suppose you'll just have
to find a way to cope, much as others of us have done when
occasionally exposed to quoted material by perennial trolls such as
Ranting Rick. For a starter, since this is the only thread he's posted
in, you could mute it.


From ian.g.kelly at gmail.com  Mon Jan  2 01:40:33 2017
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Mon, 2 Jan 2017 00:40:33 -0600
Subject: learning and experimenting python.
In-Reply-To: <CALwzid=prEqEzHu=0=HAXt-EFCPqd+q6xmX+-9ti=zTHR8Ru6Q@mail.gmail.com>
References: <6886d439-751c-42d2-adf2-fbf494221d48@googlegroups.com>
 <o47q7t$4jq$1@dont-email.me>
 <58678152$0$1622$c3e8da3$5496439d@news.astraweb.com>
 <d5a48cd6-fd0e-45eb-bac6-0bf7dc131250@googlegroups.com>
 <CALwzid=98ggNQiLNe0sVMbxN2wQ-zGecFvQf-DZ4_JRTjNZWuQ@mail.gmail.com>
 <o4beb3$8h4$1@blaine.gmane.org>
 <CALwzid=prEqEzHu=0=HAXt-EFCPqd+q6xmX+-9ti=zTHR8Ru6Q@mail.gmail.com>
Message-ID: <CALwzidkL94FCATvys2O=9nOtdk=92dGqOMBuBDiZ5xBfczVs8g@mail.gmail.com>

On Mon, Jan 2, 2017 at 12:15 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> Since they're unlikely to do that however,

Then again, I see that einstein1410 made a couple of rather aggressive
posts 11 hours ago that haven't made it to my email, so maybe he did
manage to get himself banned.


From mail at timgolden.me.uk  Mon Jan  2 02:14:19 2017
From: mail at timgolden.me.uk (Tim Golden)
Date: Mon, 2 Jan 2017 07:14:19 +0000
Subject: learning and experimenting python.
In-Reply-To: <CALwzidkL94FCATvys2O=9nOtdk=92dGqOMBuBDiZ5xBfczVs8g@mail.gmail.com>
References: <6886d439-751c-42d2-adf2-fbf494221d48@googlegroups.com>
 <o47q7t$4jq$1@dont-email.me>
 <58678152$0$1622$c3e8da3$5496439d@news.astraweb.com>
 <d5a48cd6-fd0e-45eb-bac6-0bf7dc131250@googlegroups.com>
 <CALwzid=98ggNQiLNe0sVMbxN2wQ-zGecFvQf-DZ4_JRTjNZWuQ@mail.gmail.com>
 <o4beb3$8h4$1@blaine.gmane.org>
 <CALwzid=prEqEzHu=0=HAXt-EFCPqd+q6xmX+-9ti=zTHR8Ru6Q@mail.gmail.com>
 <CALwzidkL94FCATvys2O=9nOtdk=92dGqOMBuBDiZ5xBfczVs8g@mail.gmail.com>
Message-ID: <21b1c09e-0556-693b-b743-85e927426a59@timgolden.me.uk>

On 02/01/17 06:40, Ian Kelly wrote:
> On Mon, Jan 2, 2017 at 12:15 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
>> Since they're unlikely to do that however,
>
> Then again, I see that einstein1410 made a couple of rather aggressive
> posts 11 hours ago that haven't made it to my email, so maybe he did
> manage to get himself banned.
>

We are holding (and, so far, dropping) posts from that address. FWIW I 
concur with an earlier poster that the person in question is simply 
ill-informed rather than deliberately provocative. I have sympathy with 
their initial ignorance; less with their apparent inability to learn 
from other people's well-intentioned comments.

Probably best to let the thing drop rather than let it escalate into a 
sniping war. If anyone reading this knows the poster in person, please 
help them to see how their posts have come across and whey they received 
the reaction they did.

TJG


From whoisaritra at gmail.com  Mon Jan  2 04:04:59 2017
From: whoisaritra at gmail.com (Aritra Bhattacharjee)
Date: Mon, 2 Jan 2017 01:04:59 -0800 (PST)
Subject: Unable to Debug
Message-ID: <aaec5e68-f4ff-438a-9d27-615a4895104b@googlegroups.com>

I am new to python programming. I wrote a code to search for the product names on a page of snapdeal.com .

Code:
import urllib.request
from bs4 import BeautifulSoup as BS

url = 'https://www.snapdeal.com/products/electronics-headphones?sort=plrty'

response = urllib.request.urlopen(url).read()
soup = BS(response, 'html.parser')

#for dataprice in soup.find_all('span', class_="lfloat product-price"):
#    print(dataprice)
product_name={}
i=0
for title in soup.find_all('p', class_="product-title"):
        product_name[i]=title.string
        i += 1
for i in range(1,21):
    print(product_name[i])


Output:
Traceback (most recent call last):
Motorola Pulse 2 Over Ear Wired Headphones With Mic (Black)
Bose SoundLink On-Ear Bluetooth Headphones - Black & Blue
Sony MDR-ZX110A Headphones Without Mic (White)
Philips SBCHL140/98 Over Ear Headphone Without Mic
  File "C:/Users/Aritra Bhattacharjee/PycharmProjects/PythonWebModules/Web Scraper.py", line 17, in <module>
Intex Desire BT Over Ear Wired With Mic Headphone Black
    print(product_name[i])
JBL T450 On Ear Wired Headphones With Mic Black
KeyError: 20
Motorola Pulse Max Over Ear Wired Headphones With Mic (Black)
Philips SHB7250WT/00 Over Ear Wireless Headphones With Mic White
Sony MDR-XB650BT On-Ear Extra Bass(XB) Headphones with Bluetooth & NFC (Black)
Intex JAZZ Over Ear Wired With Mic Headphone Black
Skullcandy S5GBW-J539 On Ear Wireless Headphones With Mic Black
JBL C300SI Over Ear Wired Without Mic Headphone Black
Zoook Rocker iFit Bluetooth Wireless Headphones With Mic Black
Signature VM-46 Over Ear Wired Headphone Without Mic White
Sony MDR-G45 Over Ear Wired Without Mic Headphone- Black
Motorola Pulse Max Over Ear Wired Headphones With Mic (White)
Bose SoundTrue Around-Ear Headphones with Mic (Navy Blue) for Samsung and Android Devices
JBL T450 On Ear Wired Headphones With Mic Blue
Motorola Pulse 2 Over Ear Wired Headphones With Mic (White)


The Output shows some error that I could not understand why...Thanks in Advance


From vincent.vande.vyvre at telenet.be  Mon Jan  2 04:32:34 2017
From: vincent.vande.vyvre at telenet.be (Vincent Vande Vyvre)
Date: Mon, 2 Jan 2017 10:32:34 +0100
Subject: Unable to Debug
In-Reply-To: <aaec5e68-f4ff-438a-9d27-615a4895104b@googlegroups.com>
References: <aaec5e68-f4ff-438a-9d27-615a4895104b@googlegroups.com>
Message-ID: <f624da39-433a-893c-0f02-cf3e2d659e62@telenet.be>

Le 02/01/17 ? 10:04, Aritra Bhattacharjee a ?crit :
> I am new to python programming. I wrote a code to search for the product names on a page of snapdeal.com .
>
> Code:
> import urllib.request
> from bs4 import BeautifulSoup as BS
>
> url = 'https://www.snapdeal.com/products/electronics-headphones?sort=plrty'
>
> response = urllib.request.urlopen(url).read()
> soup = BS(response, 'html.parser')
>
> #for dataprice in soup.find_all('span', class_="lfloat product-price"):
> #    print(dataprice)
> product_name={}
> i=0
> for title in soup.find_all('p', class_="product-title"):
>          product_name[i]=title.string
>          i += 1
> for i in range(1,21):
>      print(product_name[i])
>
>
> Output:
> Traceback (most recent call last):
> Motorola Pulse 2 Over Ear Wired Headphones With Mic (Black)
> Bose SoundLink On-Ear Bluetooth Headphones - Black & Blue
> Sony MDR-ZX110A Headphones Without Mic (White)
> Philips SBCHL140/98 Over Ear Headphone Without Mic
>    File "C:/Users/Aritra Bhattacharjee/PycharmProjects/PythonWebModules/Web Scraper.py", line 17, in <module>
> Intex Desire BT Over Ear Wired With Mic Headphone Black
>      print(product_name[i])
> JBL T450 On Ear Wired Headphones With Mic Black
> KeyError: 20
> Motorola Pulse Max Over Ear Wired Headphones With Mic (Black)
> Philips SHB7250WT/00 Over Ear Wireless Headphones With Mic White
> Sony MDR-XB650BT On-Ear Extra Bass(XB) Headphones with Bluetooth & NFC (Black)
> Intex JAZZ Over Ear Wired With Mic Headphone Black
> Skullcandy S5GBW-J539 On Ear Wireless Headphones With Mic Black
> JBL C300SI Over Ear Wired Without Mic Headphone Black
> Zoook Rocker iFit Bluetooth Wireless Headphones With Mic Black
> Signature VM-46 Over Ear Wired Headphone Without Mic White
> Sony MDR-G45 Over Ear Wired Without Mic Headphone- Black
> Motorola Pulse Max Over Ear Wired Headphones With Mic (White)
> Bose SoundTrue Around-Ear Headphones with Mic (Navy Blue) for Samsung and Android Devices
> JBL T450 On Ear Wired Headphones With Mic Blue
> Motorola Pulse 2 Over Ear Wired Headphones With Mic (White)
>
>
> The Output shows some error that I could not understand why...Thanks in Advance

Try with:


for i in product_name:

     print(i)


Vincent



From __peter__ at web.de  Mon Jan  2 04:37:45 2017
From: __peter__ at web.de (Peter Otten)
Date: Mon, 02 Jan 2017 10:37:45 +0100
Subject: Unable to Debug
References: <aaec5e68-f4ff-438a-9d27-615a4895104b@googlegroups.com>
Message-ID: <o4d716$re3$1@blaine.gmane.org>

Aritra Bhattacharjee wrote:

> I am new to python programming. I wrote a code to search for the product
> names on a page of snapdeal.com .
> 
> Code:
> import urllib.request
> from bs4 import BeautifulSoup as BS
> 
> url =
> 'https://www.snapdeal.com/products/electronics-headphones?sort=plrty'
> 
> response = urllib.request.urlopen(url).read()
> soup = BS(response, 'html.parser')
> 
> #for dataprice in soup.find_all('span', class_="lfloat product-price"):
> #    print(dataprice)
> product_name={}
> i=0
> for title in soup.find_all('p', class_="product-title"):
>         product_name[i]=title.string
>         i += 1
> for i in range(1,21):
>     print(product_name[i])
> 
> 
> Output:
> Traceback (most recent call last):
> Motorola Pulse 2 Over Ear Wired Headphones With Mic (Black)
> Bose SoundLink On-Ear Bluetooth Headphones - Black & Blue
> Sony MDR-ZX110A Headphones Without Mic (White)
> Philips SBCHL140/98 Over Ear Headphone Without Mic
>   File "C:/Users/Aritra Bhattacharjee/PycharmProjects/PythonWebModules/Web
>   Scraper.py", line 17, in <module>
> Intex Desire BT Over Ear Wired With Mic Headphone Black
>     print(product_name[i])
> JBL T450 On Ear Wired Headphones With Mic Black
> KeyError: 20

For the script above the output should end with the line above

[snip]

> The Output shows some error that I could not understand why...Thanks in
> Advance

You define a dict product_name and then successively add entries with

> i=0
> for title in soup.find_all('p', class_="product-title"):
>         product_name[i]=title.string
>         i += 1

This means that the first key will be 0, the second will be 1, and so on up 
to 19. In the for loop you are looking for the keys 1 to 20,

> for i in range(1,21):
>     print(product_name[i])

so the first match will not be printed, and when you ask for 
product_name[20] you will get the KeyError and the traceback.

How to fix your code? You could rewrite the for loop as

for i in range(len(product_name)):
    print(product_name[i])

which because of len() will work for pages that feature more or less than 20 
products. If you plan to remove products from the dict you have to cope with 
missing indices. On way to do this is iterate to over the values alone:

for name in product_name.values():
    print(name)

If you want to preserve the order on the html page you can iterate over the 
sorted key/value pairs:

for i, name in sorted(product_name.items()):
    print(i, name)



From rus.cahimb at gmail.com  Mon Jan  2 04:43:42 2017
From: rus.cahimb at gmail.com (rus.cahimb at gmail.com)
Date: Mon, 2 Jan 2017 01:43:42 -0800 (PST)
Subject: Unable to Debug
In-Reply-To: <aaec5e68-f4ff-438a-9d27-615a4895104b@googlegroups.com>
References: <aaec5e68-f4ff-438a-9d27-615a4895104b@googlegroups.com>
Message-ID: <1f64b59e-9d6b-487b-b367-850ccfb6b9ff@googlegroups.com>

On Monday, January 2, 2017 at 2:35:22 PM UTC+5:30, Aritra Bhattacharjee wrote:
> I am new to python programming. I wrote a code to search for the product names on a page of snapdeal.com .

[RM]: Welcome and have fun.

> for i in range(1,21):
>     print(product_name[i])
> 
> 
> Output:
> Traceback (most recent call last):
> Motorola Pulse 2 Over Ear Wired Headphones With Mic (Black)
> Bose SoundLink On-Ear Bluetooth Headphones - Black & Blue
> Sony MDR-ZX110A Headphones Without Mic (White)
> Philips SBCHL140/98 Over Ear Headphone Without Mic
>   File "C:/Users/Aritra Bhattacharjee/PycharmProjects/PythonWebModules/Web Scraper.py", line 17, in <module>
> Intex Desire BT Over Ear Wired With Mic Headphone Black
>     print(product_name[i])
> JBL T450 On Ear Wired Headphones With Mic Black
> KeyError: 20
. . . . 
. . . . 
> The Output shows some error that I could not understand why...Thanks in Advance

[RM]: You should read tracebacks stack from the bottom. Initially there will be hiccups but over a period of time you will learn.

>From your code snippet: for loop is supplied with a range of 1 to 21 and while the key value (variable, i) is 20, print fails there. In the previous loop, where you are using methods in BeautifulSoup, are you sure that many items are added to the list, product_name.

If I were you, in the loop where the list is expanded by adding the product title names, will rename the variable, i, as 'product_counter'. And, in the last for loop, this counter can be used in the rangem like, (0, product_counter).

All the best,
/Ram


From david.froger.ml at mailoo.org  Mon Jan  2 04:43:44 2017
From: david.froger.ml at mailoo.org (David Froger)
Date: Mon, 02 Jan 2017 10:43:44 +0100
Subject: Unable to Debug
In-Reply-To: <aaec5e68-f4ff-438a-9d27-615a4895104b@googlegroups.com>
References: <aaec5e68-f4ff-438a-9d27-615a4895104b@googlegroups.com>
Message-ID: <148335022401.30175.5274499245150761836@mael>

Hello Aritra,

Your standard output and standard error are mixed (I don't know why), so error
message is not immediate to read. It is:

> Traceback (most recent call last):
>   File "C:/Users/Aritra Bhattacharjee/PycharmProjects/PythonWebModules/Web Scraper.py", line 17, in <module>
>     print(product_name[i])
> KeyError: 20

There no such `20` title in `product_name`, so we can deduce that
`soup.find_all` found only 19 titles.

You can to instead:

    product_name = []  # a list instead of a dict is enought

    for title in soup.find_all('p', class_="product-title"):
        product_name.append(title.string)

    # or this should work too:
    # product_name = list(soup.find_all('p', class_="product-title"))

    for title in product_name:  # no need of i variable
        print(title)

Quoting Aritra Bhattacharjee (2017-01-02 10:04:59)
> I am new to python programming. I wrote a code to search for the product names on a page of snapdeal.com .
> 
> Code:
> import urllib.request
> from bs4 import BeautifulSoup as BS
> 
> url = 'https://www.snapdeal.com/products/electronics-headphones?sort=plrty'
> 
> response = urllib.request.urlopen(url).read()
> soup = BS(response, 'html.parser')
> 
> #for dataprice in soup.find_all('span', class_="lfloat product-price"):
> #    print(dataprice)
> product_name={}
> i=0
> for title in soup.find_all('p', class_="product-title"):
>         product_name[i]=title.string
>         i += 1
> for i in range(1,21):
>     print(product_name[i])
> 
> 
> Output:
> Motorola Pulse 2 Over Ear Wired Headphones With Mic (Black)
> Bose SoundLink On-Ear Bluetooth Headphones - Black & Blue
> Sony MDR-ZX110A Headphones Without Mic (White)
> Philips SBCHL140/98 Over Ear Headphone Without Mic
> Intex Desire BT Over Ear Wired With Mic Headphone Black
> JBL T450 On Ear Wired Headphones With Mic Black
> Motorola Pulse Max Over Ear Wired Headphones With Mic (Black)
> Philips SHB7250WT/00 Over Ear Wireless Headphones With Mic White
> Sony MDR-XB650BT On-Ear Extra Bass(XB) Headphones with Bluetooth & NFC (Black)
> Intex JAZZ Over Ear Wired With Mic Headphone Black
> Skullcandy S5GBW-J539 On Ear Wireless Headphones With Mic Black
> JBL C300SI Over Ear Wired Without Mic Headphone Black
> Zoook Rocker iFit Bluetooth Wireless Headphones With Mic Black
> Signature VM-46 Over Ear Wired Headphone Without Mic White
> Sony MDR-G45 Over Ear Wired Without Mic Headphone- Black
> Motorola Pulse Max Over Ear Wired Headphones With Mic (White)
> Bose SoundTrue Around-Ear Headphones with Mic (Navy Blue) for Samsung and Android Devices
> JBL T450 On Ear Wired Headphones With Mic Blue
> Motorola Pulse 2 Over Ear Wired Headphones With Mic (White)
> 
> 
> The Output shows some error that I could not understand why...Thanks in Advance
> -- 
> https://mail.python.org/mailman/listinfo/python-list


From jussi.piitulainen at helsinki.fi  Mon Jan  2 04:44:09 2017
From: jussi.piitulainen at helsinki.fi (Jussi Piitulainen)
Date: Mon, 02 Jan 2017 11:44:09 +0200
Subject: Cleaning up conditionals
References: <lf5zijbp6ld.fsf@ling.helsinki.fi>
 <002801d26489$d3073dd0$27b23dae@sambora>
 <mailman.107.1483314595.2395.python-list@python.org>
Message-ID: <lf5lgutkd92.fsf@ling.helsinki.fi>

Deborah Swanson writes:
> Jussi Piitulainen wrote:

[snip]

>> With your particular conditions of non-emptiness, which is taken to
>> be truth, you can achieve variations of this result with any of the
>> following statements:
>> 
>> w = ( l1[v] if len(l1[v]) > 0 else
>>       l2[v] if len(l2[v]) > 0 else
>>       l1[v] )
>> 
>> x = l1[v] if l1[v] else l2[v] if l2[v] else l1[v]
>> 
>> y = l1[v] or l2[v] or l1[v]
>> 
>> z = l1[v] or l2[v]
>> 
>> The last one, which I originally suggested (and still prefer 
>> when otherwise appropriate), is subtly different from the 
>> others. That difference should be irrelevant.
>
> I agree, if the goal was to capture one of the field values in a
> scalar value.

To store into a list, specify a position in the list as the target.

My idea here has been to simply do this to all the relevant positions in
both lists, even when it means storing the old value back.

See below, concretely, with your two examples and the mixed one from
Dennis Lee Bieber, where I introduced a small difference of my own so
that corresponding non-empty fields differ. I have made it output Python
comments and inserted them at appropriate places.

The same function, merge, fills the empty fields from the other list in
all three cases using the method z from above. It does no harm when a
field is already non-empty.

def merge(l1, l2):
    fields = range(5)
    for v in fields:
        l1[v] = l1[v] or l2[v]
        l2[v] = l2[v] or l1[v]

l1 = [ '2 br, Elk Plains', '12-26', 'WA/pi', 'house', 'garage, w/d' ]
l2 = [ '2 br, Elk Plains', '12-29', '',      '',      ''            ]

print('# Before:', l1, l2, sep = '\n# ', end = '\n# ')
merge(l1, l2)
print('After:', l1, l2, sep = '\n# ', end = '\n\n')

# Before:
# ['2 br, Elk Plains', '12-26', 'WA/pi', 'house', 'garage, w/d']
# ['2 br, Elk Plains', '12-29', '', '', '']
# After:
# ['2 br, Elk Plains', '12-26', 'WA/pi', 'house', 'garage, w/d']
# ['2 br, Elk Plains', '12-29', 'WA/pi', 'house', 'garage, w/d']

l1 = [ '2 br, Elk Plains', '12-26', '',      '',      ''            ]
l2 = [ '2 br, Elk Plains', '12-29', 'WA/pi', 'house', 'garage, w/d' ]

print('# Before:', l1, l2, sep = '\n# ', end = '\n# ')
merge(l1, l2)
print('After:', l1, l2, sep = '\n# ', end = '\n\n')

# Before:
# ['2 br, Elk Plains', '12-26', '', '', '']
# ['2 br, Elk Plains', '12-29', 'WA/pi', 'house', 'garage, w/d']
# After:
# ['2 br, Elk Plains', '12-26', 'WA/pi', 'house', 'garage, w/d']
# ['2 br, Elk Plains', '12-29', 'WA/pi', 'house', 'garage, w/d']

l1 = [ '2 br, Elk Plains', '12-26', 'WA/pi', '',      ''            ]
l2 = [ '2 br, Elf Plains', '12-29', '',      'house', 'garage, w/d' ]

print('# Before:', l1, l2, sep = '\n# ', end = '\n# ')
merge(l1, l2)
print('After:', l1, l2, sep = '\n# ', end = '\n\n')

# Before:
# ['2 br, Elk Plains', '12-26', 'WA/pi', '', '']
# ['2 br, Elf Plains', '12-29', '', 'house', 'garage, w/d']
# After:
# ['2 br, Elk Plains', '12-26', 'WA/pi', 'house', 'garage, w/d']
# ['2 br, Elf Plains', '12-29', 'WA/pi', 'house', 'garage, w/d']


From python at deborahswanson.net  Mon Jan  2 04:47:22 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 2 Jan 2017 01:47:22 -0800
Subject: Unable to Debug
In-Reply-To: <aaec5e68-f4ff-438a-9d27-615a4895104b@googlegroups.com>
Message-ID: <000f01d264dd$37f0e590$27b23dae@sambora>

Aritra Bhattacharjee wrote, on January 02, 2017 1:05 AM:
> I am new to python programming. I wrote a code to search for 
> the product names on a page of snapdeal.com .
> 
> Code:
> import urllib.request
> from bs4 import BeautifulSoup as BS
> 
> url = 
> 'https://www.snapdeal.com/products/electronics>
-headphones?sort=plrty'
> 
> response = urllib.request.urlopen(url).read()
> soup = BS(response, 'html.parser')
> 
> #for dataprice in soup.find_all('span', class_="lfloat 
> product-price"):
> #    print(dataprice)
> product_name={}
> i=0
> for title in soup.find_all('p', class_="product-title"):
>         product_name[i]=title.string
>         i += 1
> for i in range(1,21):
>     print(product_name[i])
> 
> 
> Output:
> Traceback (most recent call last):
> Motorola Pulse 2 Over Ear Wired Headphones With Mic (Black) 
> Bose SoundLink On-Ear Bluetooth Headphones - Black & Blue 
> Sony MDR-ZX110A Headphones Without Mic (White) Philips 
> SBCHL140/98 Over Ear Headphone Without Mic
>   File "C:/Users/Aritra 
> Bhattacharjee/PycharmProjects/PythonWebModules/Web 
> Scraper.py", line 17, in <module> Intex Desire BT Over Ear 
> Wired With Mic Headphone Black
>     print(product_name[i])
> JBL T450 On Ear Wired Headphones With Mic Black
> KeyError: 20
> Motorola Pulse Max Over Ear Wired Headphones With Mic (Black) 
> Philips SHB7250WT/00 Over Ear Wireless Headphones With Mic 
> White Sony MDR-XB650BT On-Ear Extra Bass(XB) Headphones with 
> Bluetooth & NFC (Black) Intex JAZZ Over Ear Wired With Mic 
> Headphone Black Skullcandy S5GBW-J539 On Ear Wireless 
> Headphones With Mic Black JBL C300SI Over Ear Wired Without 
> Mic Headphone Black Zoook Rocker iFit Bluetooth Wireless 
> Headphones With Mic Black Signature VM-46 Over Ear Wired 
> Headphone Without Mic White Sony MDR-G45 Over Ear Wired 
> Without Mic Headphone- Black Motorola Pulse Max Over Ear 
> Wired Headphones With Mic (White) Bose SoundTrue Around-Ear 
> Headphones with Mic (Navy Blue) for Samsung and Android 
> Devices JBL T450 On Ear Wired Headphones With Mic Blue 
> Motorola Pulse 2 Over Ear Wired Headphones With Mic (White)
> 
> 
> The Output shows some error that I could not understand 
> why...Thanks in Advance

This looks like Beautiful Soup. I've only used it once, and can just
barely count it as a successful use.

But what stands out to me is the "KeyError: 20", which closely follows
after the "print(product_name[i])" statement. 

If product_name is a dictionary (and I see that it is), the key error
says that none of product_name's keys has the value that was in 'i' when
the error was thrown, ie. the key equal to 20 isn't in the dictionary.

Frequently this occurs in a loop that continues beyond the length of the
dictionary. 

The error was thrown in:

for i in range(1,21):
     print(product_name[i])

so my guess is that you didn't have 20 keys in product_name, and the
error was thrown when you tried to print product_name[20].

You could try just editting the loop so it only goes up to 20, since all
the keys up to 20 were found (and range will stop the loop at one less
than the given upper bound):

for i in range(1,20):
     print(product_name[i])

although I wonder why it isn't:

for i in range(0,19):
     print(product_name[i])

since the first item in the dictionary is index 0. Unless you don't want
the first one to print for some reason.

Hope this helps.
D.



From python at deborahswanson.net  Mon Jan  2 05:37:19 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 2 Jan 2017 02:37:19 -0800
Subject: Cleaning up conditionals
In-Reply-To: <lf5lgutkd92.fsf@ling.helsinki.fi>
Message-ID: <001501d264e4$32189a80$27b23dae@sambora>

Jussi Piitulainen wrote, on January 02, 2017 1:44 AM
> 
> Deborah Swanson writes:
> > Jussi Piitulainen wrote:
> 
> [snip]
> 
> >> With your particular conditions of non-emptiness, which is 
> taken to 
> >> be truth, you can achieve variations of this result with 
> any of the 
> >> following statements:
> >> 
> >> w = ( l1[v] if len(l1[v]) > 0 else
> >>       l2[v] if len(l2[v]) > 0 else
> >>       l1[v] )
> >> 
> >> x = l1[v] if l1[v] else l2[v] if l2[v] else l1[v]
> >> 
> >> y = l1[v] or l2[v] or l1[v]
> >> 
> >> z = l1[v] or l2[v]
> >> 
> >> The last one, which I originally suggested (and still prefer
> >> when otherwise appropriate), is subtly different from the 
> >> others. That difference should be irrelevant.
> >
> > I agree, if the goal was to capture one of the field values in a 
> > scalar value.
> 
> To store into a list, specify a position in the list as the target.

Aha. Now I see your plan. Pardon me, but the single letter variable you
were assigning to, with no prior definition, seemed to me to be a
scalar. I just couldn't see how that could work. But a list,
specifically a list of the 2 rows with identical fields except for the
date, makes perfect sense.

> My idea here has been to simply do this to all the relevant 
> positions in both lists, even when it means storing the old 
> value back.

Not a problem, since it's the same value.

> See below, concretely, with your two examples and the mixed 
> one from Dennis Lee Bieber, where I introduced a small 
> difference of my own so that corresponding non-empty fields 
> differ. I have made it output Python comments and inserted 
> them at appropriate places.
> 
> The same function, merge, fills the empty fields from the 
> other list in all three cases using the method z from above. 
> It does no harm when a field is already non-empty.
> 
> def merge(l1, l2):
>     fields = range(5)
>     for v in fields:
>         l1[v] = l1[v] or l2[v]
>         l2[v] = l2[v] or l1[v]
> 
> l1 = [ '2 br, Elk Plains', '12-26', 'WA/pi', 'house', 'garage, w/d' ]
> l2 = [ '2 br, Elk Plains', '12-29', '',      '',      ''            ]
> 
> print('# Before:', l1, l2, sep = '\n# ', end = '\n# ') 
> merge(l1, l2) print('After:', l1, l2, sep = '\n# ', end = '\n\n')
> 
> # Before:
> # ['2 br, Elk Plains', '12-26', 'WA/pi', 'house', 'garage, 
> w/d'] # ['2 br, Elk Plains', '12-29', '', '', ''] # After: # 
> ['2 br, Elk Plains', '12-26', 'WA/pi', 'house', 'garage, 
> w/d'] # ['2 br, Elk Plains', '12-29', 'WA/pi', 'house', 'garage, w/d']
> 
> l1 = [ '2 br, Elk Plains', '12-26', '',      '',      ''            ]
> l2 = [ '2 br, Elk Plains', '12-29', 'WA/pi', 'house', 'garage, w/d' ]
> 
> print('# Before:', l1, l2, sep = '\n# ', end = '\n# ') 
> merge(l1, l2) print('After:', l1, l2, sep = '\n# ', end = '\n\n')
> 
> # Before:
> # ['2 br, Elk Plains', '12-26', '', '', '']
> # ['2 br, Elk Plains', '12-29', 'WA/pi', 'house', 'garage, 
> w/d'] # After: # ['2 br, Elk Plains', '12-26', 'WA/pi', 
> 'house', 'garage, w/d'] # ['2 br, Elk Plains', '12-29', 
> 'WA/pi', 'house', 'garage, w/d']
> 
> l1 = [ '2 br, Elk Plains', '12-26', 'WA/pi', '',      ''            ]
> l2 = [ '2 br, Elf Plains', '12-29', '',      'house', 'garage, w/d' ]
> 
> print('# Before:', l1, l2, sep = '\n# ', end = '\n# ') 
> merge(l1, l2) print('After:', l1, l2, sep = '\n# ', end = '\n\n')
> 
> # Before:
> # ['2 br, Elk Plains', '12-26', 'WA/pi', '', '']
> # ['2 br, Elf Plains', '12-29', '', 'house', 'garage, w/d']
> # After:
> # ['2 br, Elk Plains', '12-26', 'WA/pi', 'house', 'garage, 
> w/d'] # ['2 br, Elf Plains', '12-29', 'WA/pi', 'house', 'garage, w/d']

Very clever, and exactly what I need to accomplish. Well, the first part
of it anyway. My second test is if neither of two corresponding fields
is empty and they're different, to dump which fields are different into
a memo field, but perhaps that could be the first test and then use your
merge for the ones that are identical except for the missing data. 

An example of what I mean is:

l1 = [ '2 br, Elk Plains', '12-26', 'WA/pi', 	'']
l2 = [ '2 br, Elf Plains', '12-29', 'OR/co',    'house', 'garage, w/d' ]

which could happen if I didn't know that both Washington and Oregon have
an Elk Plains.
 
It would mean 2 functions, but if I can work in the logistics of dealing
with all the duplicates (except for the date) in one throw, 2 functions
would be worth it. And not a big deal even if I just stick to 2 rows at
a time.

In fact, just looking at the example I made up above, looks like it
would be better to test for fields that are different first, and pass on
merging the rows if any differences are found. They can always be merged
in a later run after I reconcile the descrepancies.

I'll mess around with it tomorrow, but I'll bet this works, and works
better than what I have now.



From tonycamgar at gmail.com  Mon Jan  2 06:38:53 2017
From: tonycamgar at gmail.com (Antonio Caminero Garcia)
Date: Mon, 2 Jan 2017 03:38:53 -0800 (PST)
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I do
 not know what to choose.
Message-ID: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>

Hello, I am having a hard time deciding what IDE or IDE-like code editor should I use. This can be overwhelming.

So far, I have used Vim, Sublime, Atom, Eclipse with PyDev, Pycharm, IntelliJ with Python plugin. 

The thing with the from-the-scratch full featured IDEs (Eclipse, IntelliJ, Pycharm) is that they look like a space craft dashboard and that unwarranted resources consumption and the unnecessary icons. I want my IDE to be minimalistic but powerful. My screen should be mostly ?made of code? as usually happens in Vim, Sublime or Atom. However, Pycharm is really cool and python oriented.

The problem with Vim is the learning curve, so I know the very basic stuff, but obviously not enough for coding and I do not have time to learn it, it is a pity because there are awesome plugins that turns Vim into a lightweight powerful IDE-like. So now it is not an option but I will reconsider it in the future, learning little by little. Also, I am not very fan GUI guy if the task can be accomplished through the terminal. However, I don?t understand why people underrate GUIs, that said I normally use shortcuts for the most frequent tasks and when I have to do something that is not that frequent then I do it with the mouse, for the latter case in vim you would need to look for that specific command every time. 

Sublime is my current and preferred code editor. I installed Anaconda, Git integration and a couple of additional plugins that make sublime very powerful. Also, what I like about sublime compared to the full featured IDEs, besides the minimalism, is how you can perform code navigation back and forth so fast, I mean this is something that you can also do with the others but for some subjective reason I specifically love how sublime does it. The code completion in sublime I do not find it very intelligence, the SublimeCodeIntel is better than the one that Anaconda uses but the completions are not as verbose as in the IDEs.

Now, I am thinking about giving a try to Visual Studio Code Edition (take a look, it sounds good https://marketplace.visualstudio.com/items?itemName=donjayamanne.python). I need an editor for professional software development. What would you recommend to me?


From antoon.pardon at rece.vub.ac.be  Mon Jan  2 09:09:21 2017
From: antoon.pardon at rece.vub.ac.be (Antoon Pardon)
Date: Mon, 2 Jan 2017 15:09:21 +0100
Subject: Cleaning up conditionals
In-Reply-To: <003501d262fc$90a70030$27b23dae@sambora>
References: <003501d262fc$90a70030$27b23dae@sambora>
Message-ID: <e63b9201-fa65-bf4f-cda7-3cf88ccfa45c@rece.vub.ac.be>

Op 31-12-16 om 01:26 schreef Deborah Swanson:
>> On 31 December 2016 at 10:00, Deborah Swanson 
>> <python at deborahswanson.net> wrote:
>>> Oops, indentation was messed up when I copied it into the email.
>> The indentation of your latest message looks completely 
>> broken  now, you can see it here: 
>> https://mail.python.org/pipermail/python-list/2016-December/71
> 7758.html
>
> Hm, I don't know what pipermail does with whitespace but the formatting
> in the message at
> https://mail.python.org/pipermail/python-list/2016-December/717758.html
> is not the same as the message I sent from Outlook.
>
> Again, it should have been:
>
> if len(l1[st]) == 0:
> 	if len(l2[st]) > 0:
> 		l1[st] = l2[st]
> elif len(l2[st]) == 0:
> 	if len(l1[st]) > 0:
> 		l2[st] = l1[st]

I just would like to point out that you could just eliminate each sub-if
and just write this as:

if len(l1[st]) == 0:
    l1[st] = l2[st]
elif len(l2[st]) == 0:
     l2[st] = l1[st]

If we look at the first branch the eliminated test would prevent the
assignment in case l2[st] is empty. But we already know l1[st] is empty.
So we are just eliminating the replacement of an empty field with an
empty field. There is no harm in that and trying to eliminate it just
makes your test unnecessarily complex.

-- 
Antoon Pardon 




From dr.roman.graf at gmail.com  Mon Jan  2 09:14:06 2017
From: dr.roman.graf at gmail.com (dr.roman.graf at gmail.com)
Date: Mon, 2 Jan 2017 06:14:06 -0800 (PST)
Subject: Django broken pipe error
In-Reply-To: <mailman.26.1481564307.2322.python-list@python.org>
References: <1030ce59-d2cb-4d90-b826-30637004f591@googlegroups.com>
 <843bd5a8-f127-4fdc-8817-0b1645c1872d@googlegroups.com>
 <CAO1D73H21KK14yheCLdH+LjXH_YWMaOoDM5Q7qDAm8kq1cS9QA@mail.gmail.com>
 <mailman.132.1481130930.2253.python-list@python.org>
 <e246f8df-bead-4ae4-b41e-f18f2c1ba2bb@googlegroups.com>
 <CAO1D73F+SMyA=GNs4pNtO+q6n9SXk5ppMgU2GxbM5is-s6GsFw@mail.gmail.com>
 <mailman.26.1481564307.2322.python-list@python.org>
Message-ID: <9d08e536-0a08-4f2b-b7e7-abea4b415c1d@googlegroups.com>

On Monday, December 12, 2016 at 6:38:39 PM UTC+1, justin walters wrote:
> On Mon, Dec 12, 2016 at 7:27 AM, roma <dr.roman.graf at gmail.com> wrote:
> 
> > Thanks Justin,
> >
> > I believe, the whole database story has no influence on the broken pipe
> > error. I've commented out the whole block and leave only return line:
> > return HttpResponse(res, content_type="text/plain; charset=utf-8")
> > The error is still present. And I have no influence on that.
> >
> > I call python from js client:
> >
> >     var newTrendReport = new App.TrendReport();
> >     newTrendReport.set('search_phrase', search_phrase);
> >     newTrendReport.set('time_from', time_from);
> >     newTrendReport.set('time_to', time_to);
> >     newTrendReport.set('time_scale', time_scale);
> >     newTrendReport.set('category', category);
> >     newTrendReport.startExport(
> >
> >         function(response){
> >             console.log("Successfully calculated trend report.");
> >                 App.trendPage = new App.TrendPageView();
> >                 App.trendPage.render(response);
> >         },
> >     );
> >
> > go throw:
> >
> >     App.TrendReport = Backbone.Model.extend({
> >         urlRoot: "/api/trend_reports/",
> >         defaults: {
> >             search_phrase: "",
> >             time_from: "",
> >             time_to: "",
> >             time_scale: "",
> >             category: ""
> >         },
> >
> >         startExportSuffix: "/export_report/",
> >
> >         startExport: function( successCallback, errorCallback ) {
> >             console.log("start trend calculation");
> >             var that = this;
> >             var ajaxUrl = this.startExportSuffix;
> >             var options = {
> >                 method: "POST",
> >                 data: this.attributes,
> >                 contentType: "application/json;charset=UTF-8",
> >                 dataType: "json",
> >
> >                 error: errorCallback,
> >                 success: successCallback
> >             };
> >             console.log("start trend export sync");
> >             App.ajax(ajaxUrl, options);
> >         }
> >
> >     });
> >
> > and come in export_report method.
> >
> > My urls.py:
> >
> >     url(r'^export_report', ensure_csrf_cookie(views.export_report),
> > name="export_report"),
> > --
> > https://mail.python.org/mailman/listinfo/python-list
> >
> 
> I'm not super familiar with the way backbone does http requests, but
> something seems off about the startExport function.
> It seems to me that you are sending a post request to "/export_report/"
> which is an endpoint that I'm guessing is nested
> in an include from "/api/trend_reports/". However, it looks like the error
> you're getting above says you aren't sending
> the request to "https://root.com/api/trend_reports/export_report/".
> Instead, you are sending the request to "https://root.com/export_report/" .
> Though, I'm also not sure that's the case because that would normally throw
> a 404.
> 
> I also noticed that you set content type to 'application/json' in your js,
> but the view function returns a 'text/plain' content type. Is
> There a reason for this?
> 
> The data key in your js http function is set to the attributes variable
> which, as far as I can tell, does not exist.
> 
> There's a lot going on here, but I think you can probably narrow it down to
> something in your backbone code or the way
> backbone handles http requests as the error you are getting is caused by
> the client prematurely closing the socket.
> It's possible backbone will stop reading the response since it isn't the
> same content-type as the request.

Thanks a lot Justin,

The problem was solved when I employed standard Framework methods for creation of new database object:

in JS:
var trendModel = new App.TrendModel();
    trendModel.set("phrase", search_phrase);
    trendModel.set("from_time", time_from);
    trendModel.set(...
    trendModel.save(...

in PY:
    def create(self, request):
...

I've also created extra template and additional View. PageView for some unclear reason didn't support creation of new object - this event just disappeared.

Regards,

Roman


From marcwbrooks at gmail.com  Mon Jan  2 10:47:30 2017
From: marcwbrooks at gmail.com (Marc Brooks)
Date: Mon, 2 Jan 2017 10:47:30 -0500
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
Message-ID: <CAN+KW4pRK=zd4pJrsK38Y+1VDkuPuRD4xzXRDSEwHweBMw+kPQ@mail.gmail.com>

I'd recommend you be willing to put in the time and effort to learn the
tools you want to use, if you want to do professional software
development.  Pick one, use it for a month (at least 100+ hours of hands on
keyboard coding).  Sublime, Vi are great for Python, since Python doesn't
require as much as some other languages, but you sill need to put in the
time to learn the tool.

On Mon, Jan 2, 2017 at 6:38 AM, Antonio Caminero Garcia <
tonycamgar at gmail.com> wrote:

> Hello, I am having a hard time deciding what IDE or IDE-like code editor
> should I use. This can be overwhelming.
>
> So far, I have used Vim, Sublime, Atom, Eclipse with PyDev, Pycharm,
> IntelliJ with Python plugin.
>
> The thing with the from-the-scratch full featured IDEs (Eclipse, IntelliJ,
> Pycharm) is that they look like a space craft dashboard and that
> unwarranted resources consumption and the unnecessary icons. I want my IDE
> to be minimalistic but powerful. My screen should be mostly ?made of code?
> as usually happens in Vim, Sublime or Atom. However, Pycharm is really cool
> and python oriented.
>
> The problem with Vim is the learning curve, so I know the very basic
> stuff, but obviously not enough for coding and I do not have time to learn
> it, it is a pity because there are awesome plugins that turns Vim into a
> lightweight powerful IDE-like. So now it is not an option but I will
> reconsider it in the future, learning little by little. Also, I am not very
> fan GUI guy if the task can be accomplished through the terminal. However,
> I don?t understand why people underrate GUIs, that said I normally use
> shortcuts for the most frequent tasks and when I have to do something that
> is not that frequent then I do it with the mouse, for the latter case in
> vim you would need to look for that specific command every time.
>
> Sublime is my current and preferred code editor. I installed Anaconda, Git
> integration and a couple of additional plugins that make sublime very
> powerful. Also, what I like about sublime compared to the full featured
> IDEs, besides the minimalism, is how you can perform code navigation back
> and forth so fast, I mean this is something that you can also do with the
> others but for some subjective reason I specifically love how sublime does
> it. The code completion in sublime I do not find it very intelligence, the
> SublimeCodeIntel is better than the one that Anaconda uses but the
> completions are not as verbose as in the IDEs.
>
> Now, I am thinking about giving a try to Visual Studio Code Edition (take
> a look, it sounds good https://marketplace.visualstudio.com/items?
> itemName=donjayamanne.python). I need an editor for professional software
> development. What would you recommend to me?
> --
> https://mail.python.org/mailman/listinfo/python-list
>


From torriem at gmail.com  Mon Jan  2 11:24:06 2017
From: torriem at gmail.com (Michael Torrie)
Date: Mon, 2 Jan 2017 09:24:06 -0700
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
Message-ID: <53f1736a-2e99-619b-828b-5ec70b9c09d2@gmail.com>

On 01/02/2017 04:38 AM, Antonio Caminero Garcia wrote:
> The problem with Vim is the learning curve, so I know the very basic
> stuff, but obviously not enough for coding and I do not have time to
> learn it, it is a pity because there are awesome plugins that turns
> Vim into a lightweight powerful IDE-like. So now it is not an option
> but I will reconsider it in the future, learning little by little.
> Also, I am not very fan GUI guy if the task can be accomplished
> through the terminal. However, I don?t understand why people
> underrate GUIs, that said I normally use shortcuts for the most
> frequent tasks and when I have to do something that is not that
> frequent then I do it with the mouse, for the latter case in vim you
> would need to look for that specific command every time.

Really, the basic stuff is enough to be very productive in vim.  In fact
just knowing how to save and quit is half the battle!  A little cheat
sheet for vim by your keyboard would be plenty I think.  If all you knew
was how to change modes, insert, append, change word, yank, delete, and
paste, that is 99% of what you'd use every day.  You can use normal
arrow keys, home, end, and page up and page down for cursor movement in
vim, so even if you can't remember ^,$, gg, or GG, you'll do fine.
Eventually you can begin to add in other things, like modifiers to c
(change).

There probably are a lot of nice plugins for ViM, but I use none of
them. I just don't find them that useful.  I don't seem to need any IDE
help with Python.


From walters.justin01 at gmail.com  Mon Jan  2 12:22:18 2017
From: walters.justin01 at gmail.com (justin walters)
Date: Mon, 2 Jan 2017 09:22:18 -0800
Subject: Django broken pipe error
In-Reply-To: <9d08e536-0a08-4f2b-b7e7-abea4b415c1d@googlegroups.com>
References: <1030ce59-d2cb-4d90-b826-30637004f591@googlegroups.com>
 <843bd5a8-f127-4fdc-8817-0b1645c1872d@googlegroups.com>
 <CAO1D73H21KK14yheCLdH+LjXH_YWMaOoDM5Q7qDAm8kq1cS9QA@mail.gmail.com>
 <mailman.132.1481130930.2253.python-list@python.org>
 <e246f8df-bead-4ae4-b41e-f18f2c1ba2bb@googlegroups.com>
 <CAO1D73F+SMyA=GNs4pNtO+q6n9SXk5ppMgU2GxbM5is-s6GsFw@mail.gmail.com>
 <mailman.26.1481564307.2322.python-list@python.org>
 <9d08e536-0a08-4f2b-b7e7-abea4b415c1d@googlegroups.com>
Message-ID: <CAO1D73G15GAu4=1Nx=o6EuMLbhoM+_QbS3YMk7d5ahw5SNqnFw@mail.gmail.com>

On Mon, Jan 2, 2017 at 6:14 AM, <dr.roman.graf at gmail.com> wrote:

>
> Thanks a lot Justin,
>
> The problem was solved when I employed standard Framework methods for
> creation of new database object:
>
> in JS:
> var trendModel = new App.TrendModel();
>     trendModel.set("phrase", search_phrase);
>     trendModel.set("from_time", time_from);
>     trendModel.set(...
>     trendModel.save(...
>
> in PY:
>     def create(self, request):
> ...
>
> I've also created extra template and additional View. PageView for some
> unclear reason didn't support creation of new object - this event just
> disappeared.
>
> Regards,
>
> Roman
> --
> https://mail.python.org/mailman/listinfo/python-list
>

Glad to hear that you solved the problem!


From walters.justin01 at gmail.com  Mon Jan  2 12:34:36 2017
From: walters.justin01 at gmail.com (justin walters)
Date: Mon, 2 Jan 2017 09:34:36 -0800
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
Message-ID: <CAO1D73EArdBwKdW3knNnnzX9oCEoTuvzHgDRPF7nur-hEgGJKg@mail.gmail.com>

On Mon, Jan 2, 2017 at 3:38 AM, Antonio Caminero Garcia <
tonycamgar at gmail.com> wrote:

> Hello, I am having a hard time deciding what IDE or IDE-like code editor
> should I use. This can be overwhelming.
>
> So far, I have used Vim, Sublime, Atom, Eclipse with PyDev, Pycharm,
> IntelliJ with Python plugin.
>
> The thing with the from-the-scratch full featured IDEs (Eclipse, IntelliJ,
> Pycharm) is that they look like a space craft dashboard and that
> unwarranted resources consumption and the unnecessary icons. I want my IDE
> to be minimalistic but powerful. My screen should be mostly ?made of code?
> as usually happens in Vim, Sublime or Atom. However, Pycharm is really cool
> and python oriented.
>
> The problem with Vim is the learning curve, so I know the very basic
> stuff, but obviously not enough for coding and I do not have time to learn
> it, it is a pity because there are awesome plugins that turns Vim into a
> lightweight powerful IDE-like. So now it is not an option but I will
> reconsider it in the future, learning little by little. Also, I am not very
> fan GUI guy if the task can be accomplished through the terminal. However,
> I don?t understand why people underrate GUIs, that said I normally use
> shortcuts for the most frequent tasks and when I have to do something that
> is not that frequent then I do it with the mouse, for the latter case in
> vim you would need to look for that specific command every time.
>
> Sublime is my current and preferred code editor. I installed Anaconda, Git
> integration and a couple of additional plugins that make sublime very
> powerful. Also, what I like about sublime compared to the full featured
> IDEs, besides the minimalism, is how you can perform code navigation back
> and forth so fast, I mean this is something that you can also do with the
> others but for some subjective reason I specifically love how sublime does
> it. The code completion in sublime I do not find it very intelligence, the
> SublimeCodeIntel is better than the one that Anaconda uses but the
> completions are not as verbose as in the IDEs.
>
> Now, I am thinking about giving a try to Visual Studio Code Edition (take
> a look, it sounds good https://marketplace.visualstudio.com/items?
> itemName=donjayamanne.python). I need an editor for professional software
> development. What would you recommend to me?
> --
> https://mail.python.org/mailman/listinfo/python-list
>

Have yo tried emacs? It's similar to Vim in that it relies very heavily on
keyboard shortcuts and such.
However, you may like the shortcuts a bit more or find them easier to learn.

I side with Marc Brooks in that I believe you should definitely be willing
to put in the time to learn
an editor of your choice. Becoming an expert at using an editor will make
you a lot more productive.

Personally, I use Pycharm for most of my projects as I deal with large
amounts of different files that can be
thousands of lines long. All of the code completion and structure indexing
really helps when you need to
remember the structure of large applications. Pycharm's debugger
integration is also totally awesome. I usually
use the debugger to run my tests to get more informative tracebacks or to
add breakpoints to failing tests. The git
integration is very useful as well because I personally hate Git's CLI.

For some small projects I'll use Atom as it gives me a sublime-esque
interface without forcing me to use proprietary
software.

Otherwise I'll use nano for small, single file projects.

Have you looked into ipython notebook? It's not exactly an IDE, but it does
have built in code completion and makes'
it really simple to document your code.


From best_lay at yahoo.com  Mon Jan  2 12:53:24 2017
From: best_lay at yahoo.com (Wildman)
Date: Mon, 02 Jan 2017 11:53:24 -0600
Subject: learning and experimenting python.
References: <6886d439-751c-42d2-adf2-fbf494221d48@googlegroups.com>
 <o47q7t$4jq$1@dont-email.me>
 <58678152$0$1622$c3e8da3$5496439d@news.astraweb.com>
 <d5a48cd6-fd0e-45eb-bac6-0bf7dc131250@googlegroups.com>
 <CALwzid=98ggNQiLNe0sVMbxN2wQ-zGecFvQf-DZ4_JRTjNZWuQ@mail.gmail.com>
 <o4beb3$8h4$1@blaine.gmane.org>
 <mailman.104.1483291835.2395.python-list@python.org>
 <c4d371a9-0d00-4a98-8daf-894811a9b72d@googlegroups.com>
 <W-GdnbGl-7FncPTFnZ2dnUU7-IGdnZ2d@giganews.com>
 <aa6a1985-c932-4e05-99e0-1ce47c29e6d0@googlegroups.com>
Message-ID: <OIidnYnqF8UJDvfFnZ2dnUU7-SOdnZ2d@giganews.com>

On Sun, 01 Jan 2017 23:02:34 -0800, einstein1410 wrote:

> I really don't care the person like you.
> Leave my posts, if don't like it.
> Why wasting your as well as my time.
> Just get lost man, or shut up.
     _                         _
    |_|                       |_|
    | |         /^^^\         | |
   _| |_      (| "o" |)      _| |_
 _| | | | _    (_---_)    _ | | | |_
| | | | |' |    _| |_    | `| | | | |
|          |   /     \   |          |
 \        /  / /(. .)\ \  \        /
   \    /  / /  | . |  \ \  \    /
     \  \/ /    ||Y||    \ \/  /
      \__/      || ||      \__/
                () ()
                || ||
               ooO Ooo
-- 
<Wildman> GNU/Linux user #557453
The cow died so I don't need your bull!


From irmen.NOSPAM at xs4all.nl  Mon Jan  2 13:14:02 2017
From: irmen.NOSPAM at xs4all.nl (Irmen de Jong)
Date: Mon, 2 Jan 2017 19:14:02 +0100
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
Message-ID: <586a986a$0$21519$e4fe514c@news.xs4all.nl>

On 2-1-2017 12:38, Antonio Caminero Garcia wrote:

> The thing with the from-the-scratch full featured IDEs (Eclipse, IntelliJ, Pycharm)
> is that they look like a space craft dashboard and that unwarranted resources
> consumption and the unnecessary icons. I want my IDE to be minimalistic but powerful.
> My screen should be mostly ?made of code? as usually happens in Vim, Sublime or Atom.
> However, Pycharm is really cool and python oriented.

[...]

> Sublime is my current and preferred code editor. 


If you like Sublime, and its minimalistic 'Distraction Free Mode', you'll be delighted
to know that this exact same feature is in PyCharm as well.
Select it (View->Enter distraction free mode), and gone is all the screen clutter and
even the menu bar if you so desire. You can focus on just your code. And all of
PyCharm's features are still there a mouse click or keyboard shortcut away.


Irmen


From python at deborahswanson.net  Mon Jan  2 13:40:19 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 2 Jan 2017 10:40:19 -0800
Subject: Cleaning up conditionals
In-Reply-To: <dcsk6cd89li7usgd4vrtkoj8igt7rsk8dm@4ax.com>
Message-ID: <006401d26527$ab881d80$27b23dae@sambora>

Dennis Lee Bieber wrote, on January 02, 2017 8:30 AM:
> 
> On Sun, 1 Jan 2017 18:30:03 -0800, "Deborah Swanson" 
> <python at deborahswanson.net> declaimed the following:
> 
> >Dennis Lee Bieber wrote, on Sunday, January 01, 2017 6:07 PM
> >> 
> >> 
> >> l1	2 br, Elk Plains	12-26		WA/pi
> >> l2	2 br, Elk Plains	12-29				
> >> 	house garage, w/d
> >> 
> 
> >Yes, that's exactly what I'm doing in this bit of code, 
> making all the 
> >listings that are identical except for the date be identical 
> except for 
> >the date. You may or may not have tried this approach to finding the
> 
> 	Out of curiosity -- don't those listings have street 
> addresses? There must be lots of "2 br" units in the city.
> 
> >ideal house, but this is my third house hunt, using essentially the 
> >same approach, but in a different language each time. 
> (Python is by far 
> >the best version. A dictionary with city names as keys, and several 
> >data items as values has literally cut the task in half.)
> >
> 
> 	Part of the hassle in your schema is that you are 
> treating the type of unit (2 br) AND the city (as shown in 
> your sample; I'd hope a full address is available) as a 
> single data field. Similarly, you have some obscure code 
> attached to the state.
> 
> 
> 	Maybe I've spent too much time with having to optimize 
> data structures over the last 30 years, but for my view I'd 
> end up with a relational database (most Python distributions 
> include SQLite3, so you don't have to manage a full 
> client-server system [reminds me, I still need to recreate 
> MySQL on my system, after a drive failure and OS upgrade]). 
> Something like:
> 
> create table Properties
> (
> 	ID integer auto-increment primary key,
> 	State char,
> 	City char not null,
> 	Address char not null,
> 	Type char,
> 	Code char,
> 	unique (State, City, Address)
> )
> 
> create table Listings
> (	ID integer auto-increment primary key,
> 	Property integer references Properties(ID),
> 	Date datetime,
> 	Notes varchar,
> 	unique (Property, Date)
> )
> 
> 	Since I don't know what your "code" (the "pi" above) 
> represents, I don't know if it should be in Properties or 
> Listings, nor if it is a constraint for uniqueness. Type is 
> "2 br". I put both in the Properties table as you had them 
> attached to the city and state sample data. I'd have 
> preferred to put a "not null" on State, but since that is one 
> of the fields your example allows to be blank (I presume on 
> the basis that a local town paper may assume the listing is 
> for said state)...
> 
> 	The "unique" constraints mean that any combination of 
> "State, City, Address" only appears once, same for "Property, 
> Date" combination.
> 
> 	This would be the master data, which you'd only perform 
> updates upon.
> 
> 	For an update you would formulate a SELECT using the 
> fields you have for State, City, Address (so, if no State, 
> you'd select on just City,
> Address) if multiple records are returned (only possible if 
> you are missing one of the three fields) you'd have to log 
> them as ambiguous with the new listing and needing to be hand 
> adjusted -- eg; you need to add the missing field by hand); 
> If a single record is returned you can perform an UPDATE for 
> Type/Code. If no record is returned you insert a new record 
> with the fields you have.
> 	THEN, using the unique ID of the Properties record, you 
> INSERT a new listing record with the date and notes -- if the 
> insert is rejected (duplicate Property/Date) it indicates you 
> may have already processed that listing before. You can't 
> check for that until you've determined the ID of the Property itself.
> 
> 	Determining if a property has multiple listings becomes a SELECT
> 
> select p.State, p.City, p.Address, p.Type, p.Code, 
> count(l.ID) from Properties as p inner join Listings as l on 
> p.ID = l.Property group by p.ID order by p.State, p.City, p.Address
> 
> 
> 	Yes, you might have to run periodic checks for missing 
> data fields when the field is allowed to be NULL and is part 
> of the uniqueness constraint. This would occur, for the 
> provided schema, if you had inserted a property with a null 
> State, and then later had a listing with the state provided 
> -- as the update/insert logic would come back that there is 
> no entry for (State, City, Address) -- it would not see the 
> (noState, City, Address) entry. If the State field were set 
> to "not null" you'd get an error at that time that could be 
> logged, allowing you to clean up the new data and reprocess 
> it -- instead of running a series of SELECT statements with 
> each one leaving out one of the "null allowed" fields
> 
> select p.ID, p.State, p.City, p.Address
> from Properties as p
> order by p.City, p.Address
> 
> to get all records with the same city/address (with some 
> work, and using subselects, the report could be reduced by 
> first selecting only the records where State is NULL, then 
> using just those city/addresses for the report selection. 
> It's been a while, but something like (consider all of this
> pseudocode)
> 
> select p.ID, p.State, p.City, p.Address 
> from Properties as p 
> inner join (select distinct n.City, n.Address 
> 			from Properties as n
> 			where n.State is null) as n2
> where p.City = n2.City and p.Address = n2.Address
> order by p.City, p.Address, p.State
> 
> would return all city/address combination where at least one 
> record has an empty state.
> 	
> -- 
> 	Wulfraed                 Dennis Lee Bieber         AF6VN
>     wlfraed at ix.netcom.com    HTTP://wlfraed.home.netcom.com/

I was actually planning to shift from Excel for permanent data storage
to SQLite, but as a future development and not something I'm going to do
right now. It took me 14 months to find the house I'm living in now, and
in the current real estate market it may take that long or longer to
find another one as nice this time. But if I get it all down to 15 min
of work each night that will be fine.  Haha, as long as I can afford my
new and higher rent!

Also, I just started this project and it's been kind of wild and woolly
in the early stages, which is why I need to be concerned about so many
oddball cases that won't occur when I have the operation running
smoothly. I'll be continuing to rewrite and fine tune my code for some
time, and I'd planned to do the migration to SQLite, and learn how to
use SQLite and how to use it with python after the core code is stable.
I know a smattering of SQL, but I'm not proficient with it, so I'm just
taking it all one step at a time.

But I'm keeping this message from you in my project file, so when the
time comes I'm sure I'll refer to all the helpful information you've
given in it. And I'll also be concerned about the data integrity issues
you mention, so that I can get it down to a clean, stable operation
that's reliable and takes very little time to maintain. All down the
road though, not quite yet.

As to your specific data curiosities, the '/co' part of 'st/co' is the
county, so I have state/county pairs in that field. In this case, 'pi'
is the 2 letter code for Pierce County. I may break state and county out
into 2 separate fields at some point, but it would only be advisable if
I'm actually using the county for anything other than just seeing where
it is when I look at the complete location data. State and county do go
together, and it made building the locations dictionary by hand easier
to bundle them together, but at some point I'll have all the location
data and won't be working on it anymore, and that might be the time to
separate them.  

I'm using Craiglist, and oddly enough they don't make any provision for
the address. So if one is available at all it's tucked away in 3 or 4
different places. I will be adding address and phone number fields after
I get the bulk of it under control, but I will only be doing the
detective work on places I might actually go to look at. Also, I'll
probably add local realtor's listings to my Craigslist base, but that
too is a future development. And I've kept the photos in past projects,
and would like to do that this time too, but that will probably be one
of the last things I do. About the time that I start getting serious
about going out and looking at these places.

Thanks for all your suggestions, especially about using SQLite, which I
will be doing relatively soon. I'm pretty sure there's a way to store
the photos in SQLite.



From ian.g.kelly at gmail.com  Mon Jan  2 15:46:09 2017
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Mon, 2 Jan 2017 14:46:09 -0600
Subject: learning and experimenting python.
In-Reply-To: <OIidnYnqF8UJDvfFnZ2dnUU7-SOdnZ2d@giganews.com>
References: <6886d439-751c-42d2-adf2-fbf494221d48@googlegroups.com>
 <o47q7t$4jq$1@dont-email.me>
 <58678152$0$1622$c3e8da3$5496439d@news.astraweb.com>
 <d5a48cd6-fd0e-45eb-bac6-0bf7dc131250@googlegroups.com>
 <CALwzid=98ggNQiLNe0sVMbxN2wQ-zGecFvQf-DZ4_JRTjNZWuQ@mail.gmail.com>
 <o4beb3$8h4$1@blaine.gmane.org>
 <mailman.104.1483291835.2395.python-list@python.org>
 <c4d371a9-0d00-4a98-8daf-894811a9b72d@googlegroups.com>
 <W-GdnbGl-7FncPTFnZ2dnUU7-IGdnZ2d@giganews.com>
 <aa6a1985-c932-4e05-99e0-1ce47c29e6d0@googlegroups.com>
 <OIidnYnqF8UJDvfFnZ2dnUU7-SOdnZ2d@giganews.com>
Message-ID: <CALwzidm_XJwJBQgSgGqRp2XVmTm1zacOS17=_7_ukOw7qpTJTg@mail.gmail.com>

On Jan 2, 2017 10:57 AM, "Wildman via Python-list" <python-list at python.org>
wrote:

On Sun, 01 Jan 2017 23:02:34 -0800, einstein1410 wrote:

> I really don't care the person like you.
> Leave my posts, if don't like it.
> Why wasting your as well as my time.
> Just get lost man, or shut up.
[Obscene gesture trimmed]


Way to deescalate. This is no more welcome than the post you're replying to.


From m at funkyhat.org  Mon Jan  2 16:30:25 2017
From: m at funkyhat.org (Matt Wheeler)
Date: Mon, 02 Jan 2017 21:30:25 +0000
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <53f1736a-2e99-619b-828b-5ec70b9c09d2@gmail.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
 <53f1736a-2e99-619b-828b-5ec70b9c09d2@gmail.com>
Message-ID: <CAG93HwFNkePvXWHxnoE0VNP7swKQR9z_E3NLDP2F_=6cntmhMA@mail.gmail.com>

On Mon, 2 Jan 2017 at 16:24 Michael Torrie <torriem at gmail.com> wrote:

> Really, the basic stuff is enough to be very productive in vim.  In fact
> just knowing how to save and quit is half the battle!  A little cheat
> sheet for vim by your keyboard would be plenty I think.  If all you knew
> was how to change modes, insert, append, change word, yank, delete, and
> paste, that is 99% of what you'd use every day.  You can use normal
> arrow keys, home, end, and page up and page down for cursor movement in
> vim, so even if you can't remember ^,$, gg, or GG, you'll do fine.
> Eventually you can begin to add in other things, like modifiers to c
> (change).
>

I second this. Make sure you've got all the nice Vim stuff enabled (set
nocompatible, set mouse=a etc.). And if you're not comfortable to begin
with using normal-mode commands, just stick with the mouse, arrow keys &
insert mode.
Once you get comfortable with that, perhaps set a target to learn one or
two normal-mode commands a week and go from there. I found as soon as I'd
learnt to use the direction commands & save I was already more productive
in vim than Notepad++ for example, and I just got faster from there.


> There probably are a lot of nice plugins for ViM, but I use none of
> them. I just don't find them that useful.  I don't seem to need any IDE
> help with Python.
>

On the other hand I use bags of plugins. I particularly recommend Jedi if
your computer is fast enough (it's a bit of a resource hog), and syntastic
as a great way to integrate style checkers & linters into vim.
-- 

--
Matt Wheeler
http://funkyh.at


From cs at zip.com.au  Mon Jan  2 16:54:25 2017
From: cs at zip.com.au (Cameron Simpson)
Date: Tue, 3 Jan 2017 08:54:25 +1100
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <CAG93HwFNkePvXWHxnoE0VNP7swKQR9z_E3NLDP2F_=6cntmhMA@mail.gmail.com>
References: <CAG93HwFNkePvXWHxnoE0VNP7swKQR9z_E3NLDP2F_=6cntmhMA@mail.gmail.com>
Message-ID: <20170102215425.GA98599@cskk.homeip.net>

On 02Jan2017 21:30, Matt Wheeler <m at funkyhat.org> wrote:
>On Mon, 2 Jan 2017 at 16:24 Michael Torrie <torriem at gmail.com> wrote:
>> Really, the basic stuff is enough to be very productive in vim.  In fact
>> just knowing how to save and quit is half the battle!  A little cheat
>> sheet for vim by your keyboard would be plenty I think. [...]

When I was learning vi I'd often spend a day learning a single keystroke. Not 
because they're hard, but because I wanted it in my typing muscle memory. This 
approach controlled the numberof new things I was trying to learn (roughly one 
thing at a time) while still steadily accumulating vi skills.

[...]
>Once you get comfortable with that, perhaps set a target to learn one or
>two normal-mode commands a week and go from there.

Indeed, like that!

>> There probably are a lot of nice plugins for ViM, but I use none of
>> them. I just don't find them that useful.  I don't seem to need any IDE
>> help with Python.
>
>On the other hand I use bags of plugins. I particularly recommend Jedi if
>your computer is fast enough (it's a bit of a resource hog), and syntastic
>as a great way to integrate style checkers & linters into vim.

I've been a traditional vi die hard for too long. I moved to vim (as my 
default) some years ago for: utf-8 support, syntax colouring, filename 
completion.

Recently I'm in a shiny new job with shinier newer people and am starting down 
the Dark Path of plugins. Presently I'm using ctrlp, which is a great way to 
open files in a deep/wide code tree, partiularly one which is still unfamiliar.

I guess my point here is that, as with others, you don't need to be expert with 
a particular editor; once past the basics you will be productive and you can 
steadily accrue skill with it.

Regarding IDEs, my environment is a shell terminal and a vim terminal and a 
browser for doco. Tiled windows (exactly how depends on your platform - I'm on 
a Mac at present and using Divvy to position windows).

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


From juan0christian at gmail.com  Mon Jan  2 17:13:22 2017
From: juan0christian at gmail.com (Juan C.)
Date: Mon, 2 Jan 2017 20:13:22 -0200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
Message-ID: <CAAp0bGtLcFhdnbYPwPYULu+=bSeSTnYEh_SgVcXaqMTpc7Xg+g@mail.gmail.com>

On Mon, Jan 2, 2017 at 9:38 AM, Antonio Caminero Garcia <
tonycamgar at gmail.com> wrote:
> The thing with the from-the-scratch full featured IDEs (Eclipse,
IntelliJ, Pycharm) is that they look like a space craft dashboard and that
unwarranted resources consumption and the unnecessary icons. I want my IDE
to be minimalistic but powerful. My screen should be mostly ?made of code?
as usually happens in Vim, Sublime or Atom. However, Pycharm is really cool
and python oriented.

I use Sublime Text for small scripts and PyCharm Professional for bigger
projects and I don't find it resource heavy and the interface is simple
enough. You can pretty much hide all menus and sidebars on PyCharm and
you'd get pure code (it also has a "Distraction Free" mode), I suggest you
to read Pycharm's official doc to know a little more about it. My advice is
to NOT overthink it. IDEs and code editor are just tools, just pick one you
like and you're done.


From python at deborahswanson.net  Mon Jan  2 17:52:00 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 2 Jan 2017 14:52:00 -0800
Subject: Cleaning up conditionals
In-Reply-To: <dcsk6cd89li7usgd4vrtkoj8igt7rsk8dm@4ax.com>
Message-ID: <002401d2654a$d4b0af60$27b23dae@sambora>

Dennis Lee Bieber wrote on January 02, 2017 8:30 AM
> 
> On Sun, 1 Jan 2017 18:30:03 -0800, "Deborah Swanson" 
> <python at deborahswanson.net> declaimed the following:
> 

<snip>
> 	Out of curiosity -- don't those listings have street 
> addresses? There must be lots of "2 br" units in the city.
> 

<snip>

> 	Part of the hassle in your schema is that you are 
> treating the type of unit (2 br) AND the city (as shown in 
> your sample; I'd hope a full address is available) as a 
> single data field. Similarly, you have some obscure code 
> attached to the state.

haha - what schema?

But seriously, I've loosely had one in mind all along, and there are
currently 14 columns for each listing. I've just only mentioned the
fields involved in the conditional problem I was having. One of those
fields (br) is for bedrooms, and another couple I'll add later will be
for address, phone, and local features, which may be pulled from my
locations dictionary. The Descriptions I made up for my example are very
simple short ones. Real webpage titles from Craigslist are frequently
very long, complex and full of typos. I go fishing in them for most of
the data, but I don't plan on making any effort to clean them up.

I think it was you who asked another question that I didn't answer at
the time, of why I used those weird 2-letter codes for the field names.
It's rather stupidly simple. Since the "database" will be in flux for
some time, with columns being moved around, added and deleted, I came up
with this little scheme that executes right after the csv has been
opened and read into ls[], to avoid having to change any of the
subscripts in my code whenever the columns changed:

flds = len(ls[0])
cl, ur, d1, de, lo, st, mi, ki, re, da, br, no, yn, ma, ar =
range(0,flds)

ls[0] is the title row, so the range is automatically sized to the
number of columns in the current csv. If I open a csv with more columns
than last time, I hit an IndexError right off, which is a handy reminder
if I've forgotten to update the field codes. I'd welcome anyone's
improvement on this scheme, if it accomplishes the same result.

Also, 'kind' is for the kind of property. I want a house, but I'd
consider a cottage, trailer or manufactured home if it's nice and has a
garage or a carport. And I want 2 bedrooms (one for my office), but I'm
keeping track of 1 brs & even nice studio cabins, just in case I really
need to get out of here and into something I can afford quickly. I've
also tried to screen the plexes (duplex, triplex, six-plex and what
all), apartments, condos and other undesirable "kinds" out of my
searches, but they still slip into the results anyway. Craigslist's
search function leaves much to be desired. So 'kind' also serves as a
place to snag them for later deletion. And it's a red flag when one
listing for a property comes up with 'kind' = 'house' and another comes
up 'duplex'. For some reason people like to pretend their duplexes are
houses, and sometimes they change their titles from duplex to house
after they've had to relist it a couple of times. Or they don't say what
kind of property it is, and I have to pull up the ad and look at it.

Details, details, details. ;)
D.



From greg.ewing at canterbury.ac.nz  Mon Jan  2 18:27:53 2017
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Tue, 03 Jan 2017 12:27:53 +1300
Subject: Cleaning up conditionals
In-Reply-To: <mailman.132.1483397478.2395.python-list@python.org>
References: <dcsk6cd89li7usgd4vrtkoj8igt7rsk8dm@4ax.com>
 <002401d2654a$d4b0af60$27b23dae@sambora>
 <mailman.132.1483397478.2395.python-list@python.org>
Message-ID: <ed05vrFnur5U1@mid.individual.net>

Deborah Swanson wrote:
> flds = len(ls[0])
> cl, ur, d1, de, lo, st, mi, ki, re, da, br, no, yn, ma, ar =
> range(0,flds)

You might like to consider converting the row into a
namedtuple, then you could refer to the fields using
attribute names instead of indexes.

You could even use the header row to set up the field
names in the namedtuple, so if you reorder the columns
in the file, the code would automatically adapt.

-- 
Greg


From tonycamgar at gmail.com  Mon Jan  2 18:36:06 2017
From: tonycamgar at gmail.com (Antonio Caminero Garcia)
Date: Mon, 2 Jan 2017 15:36:06 -0800 (PST)
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <mailman.122.1483374257.2395.python-list@python.org>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
 <53f1736a-2e99-619b-828b-5ec70b9c09d2@gmail.com>
 <mailman.122.1483374257.2395.python-list@python.org>
Message-ID: <4e27a90b-7963-4214-b897-bc1ef702c78d@googlegroups.com>

On Monday, January 2, 2017 at 8:24:29 AM UTC-8, Michael Torrie wrote:
> On 01/02/2017 04:38 AM, Antonio Caminero Garcia wrote:
> > The problem with Vim is the learning curve, so I know the very basic
> > stuff, but obviously not enough for coding and I do not have time to
> > learn it, it is a pity because there are awesome plugins that turns
> > Vim into a lightweight powerful IDE-like. So now it is not an option
> > but I will reconsider it in the future, learning little by little.
> > Also, I am not very fan GUI guy if the task can be accomplished
> > through the terminal. However, I don?t understand why people
> > underrate GUIs, that said I normally use shortcuts for the most
> > frequent tasks and when I have to do something that is not that
> > frequent then I do it with the mouse, for the latter case in vim you
> > would need to look for that specific command every time.
> 
> Really, the basic stuff is enough to be very productive in vim.  In fact
> just knowing how to save and quit is half the battle!  A little cheat
> sheet for vim by your keyboard would be plenty I think.  If all you knew
> was how to change modes, insert, append, change word, yank, delete, and
> paste, that is 99% of what you'd use every day.  You can use normal
> arrow keys, home, end, and page up and page down for cursor movement in
> vim, so even if you can't remember ^,$, gg, or GG, you'll do fine.
> Eventually you can begin to add in other things, like modifiers to c
> (change).
> 
> There probably are a lot of nice plugins for ViM, but I use none of
> them. I just don't find them that useful.  I don't seem to need any IDE
> help with Python.

yeah, for me I think of the IDE (and computers in general must be seen like that) as a coworker or as paring programming experience. So I agree I have been developing in Python without IDE a long time and I know if I had some features borrow from full featured IDEs will definitely   help me out.I will give a try to Vim asap, now I am trying Visual Studio now and it seems that is all I want.


From python at deborahswanson.net  Mon Jan  2 18:46:16 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 11:46:16 +1200
Subject: Clickable hyperlinks
Message-ID: <1391343616@f38.n261.z1.binkp.net>

Excel has a formula:

=HYPERLINK(url,description)

that will put a clickable link into a cell.

Does python have an equivalent function? Probably the most common use for it 
would be output to the console, similar to a print statement, but clickable.



From python at deborahswanson.net  Mon Jan  2 18:57:30 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 11:57:30 +1200
Subject: Numpy error
Message-ID: <1433087703@f38.n261.z1.binkp.net>

> ImportError:
> /home/conrado/Canopy/appdata/canopy-1.5.5.3123.rh5-x86_64/lib/
> libgfortran.so.3:
> version `GFORTRAN_1.4' not found (required by /lib64/liblapack.so.3)

Looks like you need to install the 'GFORTRAN_1.4' plugin into Canopy. I don't 
know where you'll find it, but Canopy's main website would be a good place to 
start. Or google "GFORTRAN_1.4 Canopy download".


jorge.conrado at cptec.inpe.br wrote, on January 03, 2017 6:45 AM:
>
> Hi,
>
>
> I alredy used Python and now I have the message:
>
> import numpy as np
> Traceback (most recent call last):
>    File "<stdin>", line 1, in <module>
>    File
> "/home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-
> packages/numpy-1.8.0-py2.7-linux-x86_64.egg/numpy/__init__.py",
> line 153, in <module>
>      from . import add_newdocs
>    File
> "/home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-
> packages/numpy-1.8.0-py2.7-linux-x86_64.egg/numpy/add_newdocs.py",
> line 13, in <module>
>      from numpy.lib import add_newdoc
>    File
> "/home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-
> packages/numpy-1.8.0-py2.7-linux-x86_64.egg/numpy/lib/__init__.py",
> line 18, in <module>
>      from .polynomial import *
>    File
> "/home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-
> packages/numpy-1.8.0-py2.7-linux-x86_64.egg/numpy/lib/polynomial.py",
> line 19, in <module>
>      from numpy.linalg import eigvals, lstsq, inv
>    File
> "/home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-
> packages/numpy-1.8.0-py2.7-linux-x86_64.egg/numpy/linalg/__ini
> t__.py",
> line 50, in <module>
>      from .linalg import *
>    File
> "/home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-
> packages/numpy-1.8.0-py2.7-linux-x86_64.egg/numpy/linalg/linalg.py",
> line 29, in <module>
>      from numpy.linalg import lapack_lite, _umath_linalg
> ImportError:
> /home/conrado/Canopy/appdata/canopy-1.5.5.3123.rh5-x86_64/lib/
> libgfortran.so.3:
> version `GFORTRAN_1.4' not found (required by /lib64/liblapack.so.3)
>
>
> I did:  pip istall --user numpy
>
>
> Requirement already satisfied: numpy in
> /home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-p
> ackages/numpy-1.8.0-py2.7-linux-x86_64.egg
>
>
> What can I do to solve this message.
>
>
> Thanks,
>
>
> Conrado
> --
> https://mail.python.org/mailman/listinfo/python-list
>



From python at deborahswanson.net  Mon Jan  2 19:06:42 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 12:06:42 +1200
Subject: Screwing Up looping in Generator
Message-ID: <1976089172@f38.n261.z1.binkp.net>

Sayth Renshaw wrote, on January 03, 2017 6:54 AM
>
> Hi
>
> This is simple, but its getting me confused.
>
> I have a csv writer that opens a file and loops each line of
> the file for each file and then closes, writing one file.
>
> I want to alter the behaviour to be a written file for each
> input file. I saw a roundrobin example however it failed for
> me as you cannot get len(generator) to use a while loop on.
> it exhausts
>
> should I use the same for again after the with open?
>
> rootobs in this code is my generator and I am already looping
> it however
> def data_attr(roots):
>     """Get the root object and iter items."""
>     for file in rootobs:
>         base = os.path.basename(file.name)
>         write_to = os.path.join("output",
> os.path.splitext(base)[0] + ".csv")
>         with open(write_to, 'w', newline='') as csvf:
>             race_writer = csv.writer(csvf, delimiter=',')
>             race_writer.writerow(
>                 ["meet_id", "meet_venue", "meet_date", "meet_rail",
>                  ...
>                  # other categories here
>                  ...
>                     "jockeysurname", "jockeyfirstname"])
>             for xml_data in roots:
>                 ...
>                 # parsing code
>                         for noms in race_child:
>                             if noms.tag == 'nomination':
>                                 race_writer.writerow(
>                                     [meet_id, meet_venue, meet_date,
>                                      ...
>                                     #parsing info removed
>                                         noms.get("jockeyfirstname")])
>
> Cheers
> Sayth

What's the code for your generator? And I don't see where you call
'next'.



From python at deborahswanson.net  Mon Jan  2 19:17:00 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 12:17:00 +1200
Subject: Screwing Up looping in Generator
Message-ID: <1844516036@f38.n261.z1.binkp.net>

> Sayth Renshaw wrote, on January 03, 2017 6:54 AM
> >
> > Hi
> >
> > This is simple, but its getting me confused.
> >
> > I have a csv writer that opens a file and loops each line of
> > the file for each file and then closes, writing one file.
> >
> > I want to alter the behaviour to be a written file for each
> > input file. I saw a roundrobin example however it failed for
> > me as you cannot get len(generator) to use a while loop on.
> > it exhausts
> >
> > should I use the same for again after the with open?
> >
> > rootobs in this code is my generator and I am already looping
> > it however
> > def data_attr(roots):
> >     """Get the root object and iter items."""
> >     for file in rootobs:
> >         base = os.path.basename(file.name)
> >         write_to = os.path.join("output",
> > os.path.splitext(base)[0] + ".csv")
> >         with open(write_to, 'w', newline='') as csvf:
> >             race_writer = csv.writer(csvf, delimiter=',')
> >             race_writer.writerow(
> >                 ["meet_id", "meet_venue", "meet_date", "meet_rail",
> >                  ...
> >                  # other categories here
> >                  ...
> >                     "jockeysurname", "jockeyfirstname"])
> >             for xml_data in roots:
> >                 ...
> >                 # parsing code
> >                         for noms in race_child:
> >                             if noms.tag == 'nomination':
> >                                 race_writer.writerow(
> >                                     [meet_id, meet_venue, meet_date,
> >                                      ...
> >                                     #parsing info removed
> >
> noms.get("jockeyfirstname")])
> >
> > Cheers
> > Sayth
>
> What's the code for your generator? And I don't see where you
> call 'next'.

I think you're expecting

        for file in rootobs

to get the next yield for you from rootobs, but unless someone corrects me, I 
don't think you can expect a 'for' statement to do that. You need to have a 
'next' statement inside your for loop to get the next yield from the generator.

But I might not understand exactly what you're asking.



From cs at zip.com.au  Mon Jan  2 19:33:15 2017
From: cs at zip.com.au (Cameron Simpson)
Date: Tue, 3 Jan 2017 11:33:15 +1100
Subject: trouble with cmd.Cmd and prompting
Message-ID: <20170103003315.GA29437@cskk.homeip.net>

I'm using cmd.Cmd to write a little FTP-like command line to interface to a 
storage system of mine and encountering weird behaviour. When I enter a command 
the next prompt appears _before_ the associated operation runs, or so it 
appears.

Look at this:

    [~/hg/css-venti(hg:venti)]fleet*> dev ./bin/vt -M -C - -S '[archive]' ftp ~/var/mnt/archive.vt
    stores = [<cs.venti.store.DataDirStore object at 0x10a564a90>]
    S = Store(MappingStore(ConfigWatcher('/Users/cameron/.vtrc')[archive]))
    ~/var/mnt/archive.vt:/> ls
    ~/var/mnt/archive.vt:/> precmd: line='ls'
    ---------- OnyX.dmg
    postcmd: stop=None, line='ls'

See how the cmd.Cmd prompt "~/var/mnt/archive.vt:/> " appears again right after 
the "ls", and before its output:

    precmd: line='ls'
    ---------- OnyX.dmg
    postcmd: stop=None, line='ls'

The precmd and postcmd lines are debugging, emitted from my precmd and postcmd 
methods in the subclass.

Has anyone seen this kind of thing before?

The salient parts of my class are shown below. It's not complete and I'm happy 
to post the full thing if people need to see it. The behaviour is the same 
regardless of the command; even an empty command shows it:

    ~/var/mnt/archive.vt:/> precmd: line=''
    postcmd: stop=None, line=''

    ~/var/mnt/archive.vt:/> precmd: line=''
    postcmd: stop=None, line=''

Any insights or suggestions welcome. Code below.

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

from cmd import Cmd
import readline

class FTP(Cmd):

  def __init__(self, D, sep=None, FS=None, prompt=None):
    Cmd.__init__(self)
    self._prompt = prompt
    if sep is None:
      sep = '/' # NB: _not_ os.sep
    self.root = D
    self.cwd = D
    self.sep = sep
    self.fs = FS
    self._set_prompt()

  def _set_prompt(self):
    prompt = self._prompt
    pwd = '/' + self.op_pwd()
    self.prompt = ( pwd if prompt is None else ":".join( (prompt, pwd) ) ) + '> '

  def precmd(self, line):
    X("precmd: line=%r", line)
    return line

  def postcmd(self, stop, line):
    X("postcmd: stop=%s, line=%r", stop, line)
    self._set_prompt()
    return stop

  def emptyline(self):
    pass

  def do_EOF(self, args):
    ''' Quit on end of input.
    '''
    return True

  def do_quit(self, args):
    ''' Usage: quit
    '''
    return True

  def do_ls(self, args):
    ''' Usage: ls [paths...]
    '''
    argv = shlex.split(args)
    if not argv:
      argv = sorted(self.cwd.entries.keys())
    for name in argv:
      with Pfx(name):
        E, P, tail = resolve(self.cwd, name)
        if tail:
          error("not found: unresolved path elements: %r", tail)
        else:
          M = E.meta
          S = M.stat()
          u, g, perms = M.unix_perms
          typemode = M.unix_typemode
          typechar = ( '-' if typemode == stat.S_IFREG
                  else 'd' if typemode == stat.S_IFDIR
                  else 's' if typemode == stat.S_IFLNK
                  else '?'
                     )
          print("%s%s%s%s %s" % ( typechar,
                                  rwx((typemode>>6)&7),
                                  rwx((typemode>>3)&7),
                                  rwx((typemode)&7),
                                  name
                                ))


From breamoreboy at gmail.com  Mon Jan  2 19:51:06 2017
From: breamoreboy at gmail.com (breamoreboy)
Date: Tue, 03 Jan 2017 12:51:06 +1200
Subject: pip install -r requirements.txt fails with Python 3.6 on Windows
 10
Message-ID: <611115075@f38.n261.z1.binkp.net>

On Tuesday, January 3, 2017 at 8:08:37 PM UTC, Uri Even-Chen wrote:
> Thank you, I'll consider to update our requirements to latest versions of
> all packages. Last time I checked in 22th December 2016 and all our
> requirements were the latest versions. In the meantime we can keep using
> Python 3.5. By the way, Travis CI tests passed with the same requirements
> and Python 3.6 (and 3.5 and 3.4). How did it install the requirements
> there? Does it depend on the operating system?
>
> I see now that Python 3.6.0 was released on 2016-12-23.
>
> By the way we use Ubuntu 16.04 in production with Python 3.5.2, so it's not
> that important to support Python 3.6 right now. What are the reasons to
> upgrade Python to 3.6?
>
> Thanks,
> Uri.
>
>
> *Uri Even-Chen*
> [image: photo] Phone: +972-54-3995700
> Website: http://www.speedysoftware.com/uri/en/
> <http://www.facebook.com/urievenchen>  <http://plus.google.com/+urievenchen>
>   <http://www.linkedin.com/in/urievenchen>  <http://github.com/urievenchen>
> <http://twitter.com/urievenchen>


Go here http://www.lfd.uci.edu/~gohlke/pythonlibs/#pillow to get what you need.

In all my years of downloading from this site I've never, ever had a problem.

Kindest regards.

Mark Lawrence.



From python at deborahswanson.net  Mon Jan  2 19:53:00 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 12:53:00 +1200
Subject: Screwing Up looping in Generator
Message-ID: <344519320@f38.n261.z1.binkp.net>

> > Sayth Renshaw wrote, on January 03, 2017 6:54 AM
> > >
> > > Hi
> > >
> > > This is simple, but its getting me confused.
> > >
> > > I have a csv writer that opens a file and loops each line of the
> > > file for each file and then closes, writing one file.
> > >
> > > I want to alter the behaviour to be a written file for each input
> > > file. I saw a roundrobin example however it failed for me as you
> > > cannot get len(generator) to use a while loop on. it exhausts
> > >
> > > should I use the same for again after the with open?
> > >
> > > rootobs in this code is my generator and I am already looping it
> > > however def data_attr(roots):
> > >     """Get the root object and iter items."""
> > >     for file in rootobs:
> > >         base = os.path.basename(file.name)
> > >         write_to = os.path.join("output",
> > > os.path.splitext(base)[0] + ".csv")
> > >         with open(write_to, 'w', newline='') as csvf:
> > >             race_writer = csv.writer(csvf, delimiter=',')
> > >             race_writer.writerow(
> > >                 ["meet_id", "meet_venue", "meet_date",
> "meet_rail",
> > >                  ...
> > >                  # other categories here
> > >                  ...
> > >                     "jockeysurname", "jockeyfirstname"])
> > >             for xml_data in roots:
> > >                 ...
> > >                 # parsing code
> > >                         for noms in race_child:
> > >                             if noms.tag == 'nomination':
> > >                                 race_writer.writerow(
> > >                                     [meet_id, meet_venue,
> meet_date,
> > >                                      ...
> > >                                     #parsing info removed
> > >
> > noms.get("jockeyfirstname")])
> > >
> > > Cheers
> > > Sayth
> >
> > What's the code for your generator? And I don't see where you
> > call 'next'.
>
> I think you're expecting
>
>       for file in rootobs
>
> to get the next yield for you from rootobs, but unless
> someone corrects me, I don't think you can expect a 'for'
> statement to do that. You need to have a 'next' statement
> inside your for loop to get the next yield from the generator.
>
> But I might not understand exactly what you're asking.

You probably want something like :

for f in rootobs:
    file = next
    base = os.path.basename(file.name)
       .
       .
       .
      (etc)

Notice I changed your iterating variable name to 'f', so you can use
'file' throughout your code after you get the next one from rootobs.

As written, you'll get a StopIteration exception when rootobs runs out of 
files, which you can catch with a try/except. Or you can just let the code end 
there if you're done.



From python at deborahswanson.net  Mon Jan  2 19:53:11 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 2 Jan 2017 16:53:11 -0800
Subject: Cleaning up conditionals
In-Reply-To: <ed05vrFnur5U1@mid.individual.net>
Message-ID: <003901d2655b$c2676130$27b23dae@sambora>

Gregory Ewing wrote, on Monday, January 02, 2017 3:28 PM
> 
> Deborah Swanson wrote:
> > flds = len(ls[0])
> > cl, ur, d1, de, lo, st, mi, ki, re, da, br, no, yn, ma, ar =
> > range(0,flds)
> 
> You might like to consider converting the row into a 
> namedtuple, then you could refer to the fields using 
> attribute names instead of indexes.
> 
> You could even use the header row to set up the field
> names in the namedtuple, so if you reorder the columns
> in the file, the code would automatically adapt.
> 
> -- 
> Greg

I actually tried putting them into a list early on, but the problem was
that it didn't do its main job, which is to help me avoid having to
rewrite code everytime the columns change. Once you put the field names
or codes into any kind of sequence, they can no longer be used as scalar
indices without rewriting code to use their new indices in the tuple or
list. Not really any kind of major improvement over counting out each
one's position in the row.

Unless you know of, and are suggesting, a way to index a sequence with
strings instead of integers, so the code could remain untouched with
string indices when changes to the columns are made. Certainly might be
possible, I simply haven't and probably wouldn't have thought of it
since what I have works and I've got tons of other stuff to do.

So here's the new question: Is it possible to index a sequence with
strings instead of integers?  (Dictionaries excluded because dicts are
not sequentially ordered in python 3.5 and earlier. Although, I've read
that they will be in 3.6 or beyond.)

Also, for such a scheme to be superior to what I already have, it needs
to be very nearly self-maintaining. I only touch the 2nd of those two
lines when I'm adding or deleting columns.



From jeanpierreda at gmail.com  Mon Jan  2 19:57:08 2017
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Tue, 03 Jan 2017 12:57:08 +1200
Subject: Clickable hyperlinks
Message-ID: <1059698736@f38.n261.z1.binkp.net>

Sadly, no. :(  Consoles (and stdout) are just text, not hypertext. The way to 
make an URL clickable is to use a terminal that makes URLs clickable, and print 
the URL:

print("%s: %s" % (description, url))

-- Devin

On Tue, Jan 3, 2017 at 11:46 AM, Deborah Swanson <python at deborahswanson.net> 
wrote:

> Excel has a formula:
>
> =HYPERLINK(url,description)
>
> that will put a clickable link into a cell.
>
> Does python have an equivalent function? Probably the most common use
> for it would be output to the console, similar to a print statement, but
> clickable.
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>



From tim at akwebsoft.com  Mon Jan  2 20:04:54 2017
From: tim at akwebsoft.com (Tim Johnson)
Date: Mon, 2 Jan 2017 16:04:54 -0900
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
Message-ID: <20170103010454.GA18910@mail.akwebsoft.com>

* Antonio Caminero Garcia <tonycamgar at gmail.com> [170102 02:50]:
<....> 

> Now, I am thinking about giving a try to Visual Studio Code
> Edition (take a look, it sounds good
> https://marketplace.visualstudio.com/items?itemName=donjayamanne.python).
> I need an editor for professional software development. What would
> you recommend to me?
  The best thing - as has been emphasised by others regarding this
  topic - is to establish tools, stick with them and learn them
  well.

  I use two approaches on linux:

  1)From Gnome terminal I run MC (midnight commander) as my default
  file manager with vim (in terminal mode) as the MC default editor.
  This method is used for ad-hoc editing of python source code, but
  also for system editing in general.

  2)I use emacs with elpy mode in GUI mode for large-scale work.
  Elpy is so helpful, I'm almost embarassed to admit being a
  pythonist. To compound the embarassment, the elpy developer is
  extremely helpful and very generous. :)

  -> I've used gvim (GUI mode) extensively in the past. 

  I find vim more "nimble", thus my preferance for quick-and-dirty
  edits. 
  
  Emacs, on the other hand, is enormously extendable and I have
  implemented extensive keymapping. For me, augmenting keymapping
  with the emacs help system trumps vim's more nimble approach. 
  
  In addition, I've implemented an auxilary help system using emacs'
  built-in browser so that I can call up category - based
  "cheat-sheats" with simple html highlighting and hyperlinking.

  My caveat is that both vim and emacs are a tough learning curve.
  Vimscript extends vim, elisp extends emacs. In both cases, one is
  essentially learning an additional programming language. 

  One's personal preference for input devices should also be
  considered, IMHO :

  I prefer the keyboard over pointing devices and a trackball over a
  mouse for pointing device. I use a small-footprint 68-key
  tenkeyless keyboard with a standalone keypad with my left hand
  (trackball is on the right). I've also programmed the keypad
  extensively for emacs.

  The bottom line, as others have stated, is to consistently stick
  with some approach that fits one's personal preferences. 
  
  We are fortunate to have so many options. 
  
-- 
Tim 
http://www.akwebsoft.com, http://www.tj49.com


From python at deborahswanson.net  Mon Jan  2 20:19:16 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 13:19:16 +1200
Subject: Screwing Up looping in Generator
Message-ID: <3293268733@f38.n261.z1.binkp.net>


> > > Sayth Renshaw wrote, on January 03, 2017 6:54 AM
> > > >
> > > > Hi
> > > >
> > > > This is simple, but its getting me confused.
> > > >
> > > > I have a csv writer that opens a file and loops each line of the
> > > > file for each file and then closes, writing one file.
> > > >
> > > > I want to alter the behaviour to be a written file for
> each input
> > > > file. I saw a roundrobin example however it failed for
> me as you
> > > > cannot get len(generator) to use a while loop on. it exhausts
> > > >
> > > > should I use the same for again after the with open?
> > > >
> > > > rootobs in this code is my generator and I am already looping it
> > > > however def data_attr(roots):
> > > >     """Get the root object and iter items."""
> > > >     for file in rootobs:
> > > >         base = os.path.basename(file.name)
> > > >         write_to = os.path.join("output",
> > > > os.path.splitext(base)[0] + ".csv")
> > > >         with open(write_to, 'w', newline='') as csvf:
> > > >             race_writer = csv.writer(csvf, delimiter=',')
> > > >             race_writer.writerow(
> > > >                 ["meet_id", "meet_venue", "meet_date",
> > "meet_rail",
> > > >                  ...
> > > >                  # other categories here
> > > >                  ...
> > > >                     "jockeysurname", "jockeyfirstname"])
> > > >             for xml_data in roots:
> > > >                 ...
> > > >                 # parsing code
> > > >                         for noms in race_child:
> > > >                             if noms.tag == 'nomination':
> > > >                                 race_writer.writerow(
> > > >                                     [meet_id, meet_venue,
> > meet_date,
> > > >                                      ...
> > > >                                     #parsing info removed
> > > >
> > > noms.get("jockeyfirstname")])
> > > >
> > > > Cheers
> > > > Sayth
> > >
> > > What's the code for your generator? And I don't see where
> you call
> > > 'next'.
> >
> > I think you're expecting
> >
> >     for file in rootobs
> >
> > to get the next yield for you from rootobs, but unless
> > someone corrects me, I don't think you can expect a 'for'
> > statement to do that. You need to have a 'next' statement
> > inside your for loop to get the next yield from the generator.
> >
> > But I might not understand exactly what you're asking.
>
> You probably want something like :
>
> for f in rootobs:
>     file = next
>     base = os.path.basename(file.name)
>        .
>        .
>        .
>       (etc)
>
> Notice I changed your iterating variable name to 'f', so you
> can use 'file' throughout your code after you get the next
> one from rootobs.
>
> As written, you'll get a StopIteration exception when rootobs
> runs out of files, which you can catch with a try/except. Or
> you can just let the code end there if you're done.

Well rats, I'm embarrassed. It's been awhile since I've used a generator and I 
forgot that you have to create the generator object first and use it to call 
the next function. And I really don't think you can use a generator as your 
range in a for loop. So I'd use a 'while True', and break out of the loop when 
you hit the StopIteration exception:

files = rootobs()

while True:
  try:
    file = files.next()
  except StopIteration:
    break

    base = os.path.basename(file.name)
       .
       .
       .
      (etc)

(Now I'm just going to shut up, until somebody else says something.)



From python at deborahswanson.net  Mon Jan  2 20:34:48 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 13:34:48 +1200
Subject: Clickable hyperlinks
Message-ID: <2633604084@f38.n261.z1.binkp.net>

Devin Jeanpierre wrote, on January 03, 2017 12:57 PM

>Sadly, no. :(  Consoles (and stdout) are just text, not hypertext. The
way to
>make an URL clickable is to use a terminal that makes URLs clickable,
and
>print the URL:
>
>
>print("%s: %s" % (description, url))
>
>
>
>
>-- Devin

I'm sorry, I should have said a GUI console because I wouldn't expect a 
text-based console to produce clickable links. But it appears that a simple GUI 
console can't do it either. I have 3 GUI consoles and in all 3, when I ask:

print("%s: %s" % ("python.org list", 
"https://mail.python.org/mailman/listinfo/python-list"))

I get:
python.org list: https://mail.python.org/mailman/listinfo/python-list

(Outlook made the url clickable here, the python GUI consoles just output plain 
text.)

Pretty clearly the output is plain text because your format parameters are %s. 
Maybe the trick, if there is one, is in a format parameter for urls.



On Tue, Jan 3, 2017 at 11:46 AM, Deborah Swanson
<python at deborahswanson.net> wrote:

Excel has a formula:

=HYPERLINK(url,description)

that will put a clickable link into a cell.

Does python have an equivalent function? Probably the most common use for it 
would be output to the console, similar to a print statement, but clickable.

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



From breamoreboy at gmail.com  Mon Jan  2 20:41:44 2017
From: breamoreboy at gmail.com (breamoreboy)
Date: Tue, 03 Jan 2017 13:41:44 +1200
Subject: How Best to Coerce Python Objects to Integers?
Message-ID: <3683906776@f38.n261.z1.binkp.net>

Hi all, I'd suggest that this http://blog.pyspoken.com/2017/01/02/how-best-to-c 
oerce-python-objects-to-integers/ is not one of the greatest articles ever 
written about Python exception handling.  Other opinions are welcome.

Kindest regards.

Mark Lawrence.



From steve+python at pearwood.info  Mon Jan  2 20:57:40 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Tue, 03 Jan 2017 12:57:40 +1100
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
Message-ID: <586b0517$0$1584$c3e8da3$5496439d@news.astraweb.com>

On Mon, 2 Jan 2017 10:38 pm, Antonio Caminero Garcia wrote:

> Hello, I am having a hard time deciding what IDE or IDE-like code editor
> should I use. This can be overwhelming.

Linux is my IDE.

https://sanctum.geek.nz/arabesque/series/unix-as-ide/


I dislike the Unix-style Vim/Emacs text editors, I prefer a traditional
GUI-based editor. So my "IDE" is:

- Firefox, for doing searches and looking up documentation;

- an GUI programmer's editor, preferably one with a tab-based 
  interface, such as geany or kate;

- a tab-based terminal.

Both geany and kate offer auto-completion based on previously seen words.
They won't auto-complete function or method signatures, but in my my
experience this is the "ninety percent" solution: word-based auto-complete
provides 90% of the auto-complete functionality without the cost of full
signature-based auto-complete.

In the terminal, I have at least three tabs open: one open to the Python
interactive interpreter, for testing code snippets and help(obj); one where
I run my unit tests ("python -m unittest myproject_tests"); and one where I
do any assorted other tasks, such as file management, checking code into
the repo, etc.

I've played with mypy a few times, but not used it seriously in any
projects. If I did, I would run that from the command line too, like the
unit tests. Likewise for any linters or equivalent.


> So far, I have used Vim, Sublime, Atom, Eclipse with PyDev, Pycharm,
> IntelliJ with Python plugin.
> 
> The thing with the from-the-scratch full featured IDEs (Eclipse, IntelliJ,
> Pycharm) is that they look like a space craft dashboard and that
> unwarranted resources consumption and the unnecessary icons. 

Indeed. If they provide any useful functionality I don't already have, I've
never come across it. The only thing I'd like to try is an editor that
offers semantic highlighting instead of syntax highlighting:

https://medium.com/@evnbr/coding-in-color-3a6db2743a1e

I once tried Spyder as an IDE, and found that it was so bloated and slow it
couldn't even keep up with my typing. I'm not even a touch typist! I'd
start to type a line like:

    except ValueError as err:


and by the time my fingers were hitting the colon, Spyder was displaying
`excep` in red flagged with an icon indicating a syntax error.




-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From python at deborahswanson.net  Mon Jan  2 21:14:50 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 14:14:50 +1200
Subject: Screwing Up looping in Generator
Message-ID: <3060726271@f38.n261.z1.binkp.net>

Terry Reedy
>
> On 1/3/2017 3:53 PM, Deborah Swanson wrote:
>
> >> I think you're expecting
> >>
> >>    for file in rootobs
> >>
> >> to get the next yield for you from rootobs, but unless someone
> >> corrects me, I don't think you can expect a 'for' statement to do
> >> that. You need to have a 'next' statement inside your for
> loop to get
> >> the next yield from the generator.
>
> As I read this, out of context, it is wrong.  It it very
> unusual to call
> next on the current iterator (here next(rootobs)), inside a for loop.
>
> > You probably want something like :
> >
> > for f in rootobs:
> >     file = next
>
> This is definitely wrong, as it makes 'find' an alias for the next()
> function.
>
> >     base = os.path.basename(file.name)
>
> and file.name will be an AttributeError.
>
> ---
> If one wants to iterate through files and lines within files, which I
> believe I saw in this thread, one should have a for loop
> within a for loop.
>
> --
> Terry Jan Reedy

Yes, my first attempts were screwups. I didn't remember generator usage 
correctly, but I believe my last answer was correct:

...you have to create the generator object first and use it to call the next 
function. And I really don't think you can use a generator as your range in a 
for loop. So I'd use a 'while True', and break out of the loop when you hit the 
StopIteration exception:

files = rootobs()

while True:
  try:
    file = files.next()
  except StopIteration:
    break

    base = os.path.basename(file.name)
       .
       .
       .
      (etc)



From larry at hastings.org  Mon Jan  2 21:20:56 2017
From: larry at hastings.org (Larry Hastings)
Date: Mon, 2 Jan 2017 18:20:56 -0800
Subject: [RELEASED] Python 3.4.6rc1 and Python 3.5.3rc1 are now available
Message-ID: <4437910e-0f87-2d2d-062e-8e4fc0be2a58@hastings.org>


On behalf of the Python development community and the Python 3.4 and 
Python 3.5 release teams, I'm pleased to announce the availability of 
Python 3.4.6rc1 and Python 3.5.6rc1.

Python 3.4 is now in "security fixes only" mode.  This is the final 
stage of support for Python 3.4.  Python 3.4 now only receives security 
fixes, not bug fixes, and Python 3.4 releases are source code only--no 
more official binary installers will be produced.

Python 3.5 is still in active "bug fix" mode.  Python 3.5.3rc1 contains 
many incremental improvements over Python 3.5.2.

Both these releases are "release candidates".  They should not be 
considered the final releases, although the final releases should 
contain only minor differences.  Python users are encouraged to test 
with these releases and report any problems they encounter.


You can find Python 3.4.6rc1 here:

    https://www.python.org/downloads/release/python-346rc1/

And you can find Python 3.5.3rc1 here:

    https://www.python.org/downloads/release/python-353rc1/


Python 3.4.6 final and Python 3.5.3 final are both scheduled for release 
on January 16th, 2017.


Happy New Year,


//arry/


From ethan at stoneleaf.us  Mon Jan  2 21:42:52 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 03 Jan 2017 14:42:52 +1200
Subject: How Best to Coerce Python Objects to Integers?
Message-ID: <42841261@f38.n261.z1.binkp.net>

On 01/03/2017 01:41 PM, breamoreboy at gmail.com wrote:

> Hi all, I'd suggest that this [1] is not one of the greatest articles
>  ever written about Python exception handling.  Other opinions are welcome.

Aside from calling "except Exception" a "naked except" I think it's decent.  He 
walks through the problem, explains the rationale, and only has one line of 
code guarded by the except clause.

--
~Ethan~

[1] http://blog.pyspoken.com/2017/01/02/how-best-to-coerce-python-objects-to-in 
tegers/



From python at deborahswanson.net  Mon Jan  2 22:05:20 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 15:05:20 +1200
Subject: Screwing Up looping in Generator
Message-ID: <3955896007@f38.n261.z1.binkp.net>

Chris Angelico wrote, on January 03, 2017 2:31 PM
>
> On Wed, Jan 4, 2017 at 8:19 AM, Deborah Swanson
> <python at deborahswanson.net> wrote:
> > while True:
> >   try:
> >     file = files.next()
> >   except StopIteration:
> >     break
>
> Small side point: Try to avoid calling a generator object's
> .next() method directly. Normally, when you _do_ want to do
> this, you should be calling next(files). In Python 3, the
> magic method is now __next__(), which emphasizes that it's
> for defining, not calling.
>
> As others have pointed out, though, the for loop is the
> correct tool for this job.
>
> ChrisA

Ok, I learned how to use generators in Python 2.7.8, which may be different 
from Python 3 for generators. But I learned from MIT's online introduction to 
python course, and they certainly seem to know python well. So what is the 
correct way to call the generator's next yield in Python 3? We only learned to 
use the next function. If you don't use the next function, what do you use?

And yes, we usually used for loops for generators, unless you don't know when 
the generator will be exhausted. As in this case, where the number of files the 
generator can provide is unknown. Then we used the while True, break on 
StopIteration method.



From ethan at stoneleaf.us  Mon Jan  2 22:09:52 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 03 Jan 2017 15:09:52 +1200
Subject: How Best to Coerce Python Objects to Integers?
Message-ID: <980704833@f38.n261.z1.binkp.net>

On 01/03/2017 02:47 PM, Chris Angelico wrote:
> On Wed, Jan 4, 2017 at 9:42 AM, Ethan Furman wrote:

>> Aside from calling "except Exception" a "naked except"
>
> If you read the comments, you'll see that he originally had an actual
> bare except clause, but then improved the code somewhat in response to
> a recommendation that SystemExit etc not be caught.

I did read the comments and noticed the reasons for the improved code; fixing 
the article to not use the "naked except" phrase would be another improvement.

And, of course, whether or not "except Exception" is too broad depends on the 
use-case.

--
~Ethan~



From python at deborahswanson.net  Mon Jan  2 22:21:10 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 15:21:10 +1200
Subject: Screwing Up looping in Generator
Message-ID: <3193713134@f38.n261.z1.binkp.net>



-----Original Message-----
From: Matt Wheeler [mailto:m at funkyhat.org]
Sent: Tuesday, January 03, 2017 1:47 PM To: python at deborahswanson.net; Sayth 
Renshaw; python-list at python.org
Subject: Re: Screwing Up looping in Generator


On Tue, 3 Jan 2017 at 20:17 Deborah Swanson <python at deborahswanson.net> wrote:

> What's the code for your generator? And I don't see where you
> call 'next'.

I think you're expecting

        for file in rootobs

to get the next yield for you from rootobs, but unless someone corrects me, I 
don't think you can expect a 'for' statement to do that. You need to have a 
'next' statement inside your for loop to get the next yield from the generator.




Yes, you absolutely can expect a for statement to do that. It will accept any 
iterable as its `y`.

>> And here is someone correcting me, which I sort of suspected there
might be. Yes,
>> range is an iterator, but I didn't know a generator could also be
used as an iterator.
>> Makes perfect sense though, a generator does dispense its yields in
the sequence
>> defined by the generator.


`for x in y: stuff(x)` is effectively syntactic sugar for:


iterator = iter(y)
while True:
    try:
        x = next(iterator)
    except(StopIteration):
        break
    stuff(x)

Manually calling `next()` inside a `while True:` is quite an unusual thing to 
do.

>> And you don't need to do it very often. The only use case I know is
this one, where the number of yields the generator can output is unknown (here, 
the number of files the generator can access is unknown). You might recall that 
the original poster wanted to use a while, but didn't know how to terminate it. 
At least that's how I interpreted what he was saying.


range() is not part of the for syntax at all, it's completely separate, it 
simply returns an iterator which the for loop can use, like any other.
--

>> I see that now, I just didn't know a generator could be used as an
iterator.

--
Matt Wheeler
http://funkyh.at



From no.email at nospam.invalid  Mon Jan  2 22:22:10 2017
From: no.email at nospam.invalid (Paul Rubin)
Date: Tue, 03 Jan 2017 15:22:10 +1200
Subject: Simulating int arithmetic with wrap-around
References: <1362463823@f38.n261.z1.binkp.net>
Message-ID: <3917850917@f38.n261.z1.binkp.net>

Steve D'Aprano <steve+python at pearwood.info> writes:
> Again, assume both operands are in range for an N-bit signed integer. What's
> a good way to efficiently, or at least not too inefficiently, do the
> calculations in Python?

My first thought is towards the struct module, especially if you want to handle 
a bunch of such integers at the same time.  Or maybe the array module or some 
combination.  Or a C extension.



From python at deborahswanson.net  Mon Jan  2 22:32:04 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 15:32:04 +1200
Subject: Clickable hyperlinks
Message-ID: <1124150781@f38.n261.z1.binkp.net>

Grant Edwards wrote, on January 03, 2017 3:13 PM
>
> On 2017-01-03, Deborah Swanson <python at deborahswanson.net> wrote:
>
> > I'm sorry, I should have said a GUI console because I
> wouldn't expect
> > a text-based console to produce clickable links.
>
> What's a "GUI console"?
>
> --
> Grant Edwards               grant.b.edwards        Yow! I
> want you to MEMORIZE
>                                   at               the
> collected poems of
>                               gmail.com            EDNA ST
> VINCENT MILLAY

The GUI consoles I have are in Pycharm, the IDLE that comes with Anaconda, and 
Spyder. PyCharm and IDLE both ask for internet access when I open them, so 
they're capable of opening links, but whether that means their output space is 
capable of handling clickable links I don't know.

I do know printing a full url with the %s specifier or entering a url and 
clicking enter just gives you the plain text url. Obviously, not all GUI 
consoles are enabled recognize and make clickable links from
correctly formatted urls.

I was hoping there was some functionality in python to make clickable links. 
Could be a package, if the core language doesn't have it.



From no.email at nospam.invalid  Mon Jan  2 22:33:08 2017
From: no.email at nospam.invalid (Paul Rubin)
Date: Tue, 03 Jan 2017 15:33:08 +1200
Subject: Cleaning up conditionals
Message-ID: <93733970@f38.n261.z1.binkp.net>

"Deborah Swanson" <python at deborahswanson.net> writes:
> I'm still wondering if these 4 lines can be collapsed to one or two
> lines.

In the trade that's what we call a "code smell", a sign that code (even if it 
works) should probably be re-thought after taking a step back to understand 
what it is really trying to do.

What you seem to want is to take two strings, and if exactly one of them is 
empty, then change the empty one to be the same as the non-empty one. Leaving 
aside the subscripts and just calling them x and y,

   x, y = x or y, y or x

is a concise way to do it.

That's also smelly since 1) it's overly cute, and 2) it's not clear to me why 
you'd want to do this operation.  It seems like an odd thing to want so maybe 
there's some different way to solve the surrounding problem.  If you want to 
describe the actual application and context where this appears, that might get 
some helpful comments.



From cr2001 at hotmail.co.nz  Mon Jan  2 22:49:14 2017
From: cr2001 at hotmail.co.nz (cr2001)
Date: Tue, 03 Jan 2017 15:49:14 +1200
Subject: Hey, I'm new to python so don't judge.
Message-ID: <1223999572@f38.n261.z1.binkp.net>

Im doing a new task from my teacher but i can't seem to find what is wrong with 
this code. Can anyone help?

#mynumber.py
# this game uses a home made function
import random

#think of a number
computer_number = number.randint(1,100)

#create the function is_same()
def is_same(target, number:
        if target == number:
            result="win"
        elif target > number:
            result="low"
        else:
            result="high"
        return result

# start the game
print("hello. \nI have thought of a number between 1 and 100.")

#collect the user's guess as an interger
guess = int(input("Can you guess it? "))
#Use our function
higher_or_lower = is_same(computer_number, guess)
#run the game untill the user is correct
while higher_or_lower != "win"
    if higher_or_lower == "to low"
         guess = int(input("Sorry, you are too low. Try again."))
    else:
        guess = int(input("Sorry your are too high. Try again."))

    higher_or_lower = is_same(computer_number, guess)

#end of game
input("Correct!\nWell Done\n\n\nPress RETURN to exit.")



From greg.ewing at canterbury.ac.nz  Mon Jan  2 22:57:56 2017
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Tue, 03 Jan 2017 16:57:56 +1300
Subject: Cleaning up conditionals
In-Reply-To: <mailman.133.1483404757.2395.python-list@python.org>
References: <ed05vrFnur5U1@mid.individual.net>
 <003901d2655b$c2676130$27b23dae@sambora>
 <mailman.133.1483404757.2395.python-list@python.org>
Message-ID: <ed0lq6Fr91oU1@mid.individual.net>

Deborah Swanson wrote:
> Unless you know of, and are suggesting, a way to index a sequence with
> strings instead of integers, so the code could remain untouched with
> string indices when changes to the columns are made.

I'm talking about this:

https://docs.python.org/3/library/collections.html#collections.namedtuple

It's like a tuple, but the fields also have names, so
you can access them like attributes using dot-notation.

> Also, for such a scheme to be superior to what I already have, it needs
> to be very nearly self-maintaining.

If you derive the attribute names from the header row,
it would be extremely self-maintaining. You would be able
to reorder columns without touching the code at all.

-- 
Greg


From cr2001 at hotmail.co.nz  Mon Jan  2 23:02:14 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 03 Jan 2017 16:02:14 +1200
Subject: Hey, I'm new to python so don't judge.
References: <1223999572@f38.n261.z1.binkp.net>
Message-ID: <2842576650@f38.n261.z1.binkp.net>

When i check the code it comes up with invalid syntax and my writing line gets 
re directed here

def is_same(target, number:
        if target == number:
            result="win"
        elif target > number:
            result="low"
        else:
            result="high"
        return result



From cr2001 at hotmail.co.nz  Mon Jan  2 23:16:36 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 03 Jan 2017 16:16:36 +1200
Subject: Hey, I'm new to python so don't judge.
References: <731385204@f38.n261.z1.binkp.net>
Message-ID: <2481169416@f38.n261.z1.binkp.net>

On Wednesday, January 4, 2017 at 1:03:18 PM UTC+13, Erik wrote:
> On 03/01/17 23:56, Chris Angelico wrote:
> > On Wed, Jan 4, 2017 at 10:49 AM,  <cr2001 at hotmail.co.nz> wrote:
> >> #think of a number
> >> computer_number = number.randint(1,100)
> >
> > What's wrong is that you aren't showing us the exception you get on
> > this line. *Copy and paste* that exception - the whole thing. It's
> > very helpful.
>
> I doubt it's getting that far (I can see at least one syntax error in
> the code pasted).
>
> cr2001: I echo Chris's sentiment though - what is the error you are
> seeing (in it's entirety)?
>
> E.

My apologizes but i'm quite new and would need instructions to what information 
you need me to get.



From ethan at stoneleaf.us  Mon Jan  2 23:25:25 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Mon, 02 Jan 2017 20:25:25 -0800
Subject: learning and experimenting python.
In-Reply-To: <OIidnYnqF8UJDvfFnZ2dnUU7-SOdnZ2d@giganews.com>
References: <6886d439-751c-42d2-adf2-fbf494221d48@googlegroups.com>
 <o47q7t$4jq$1@dont-email.me>
 <58678152$0$1622$c3e8da3$5496439d@news.astraweb.com>
 <d5a48cd6-fd0e-45eb-bac6-0bf7dc131250@googlegroups.com>
 <CALwzid=98ggNQiLNe0sVMbxN2wQ-zGecFvQf-DZ4_JRTjNZWuQ@mail.gmail.com>
 <o4beb3$8h4$1@blaine.gmane.org>
 <mailman.104.1483291835.2395.python-list@python.org>
 <c4d371a9-0d00-4a98-8daf-894811a9b72d@googlegroups.com>
 <W-GdnbGl-7FncPTFnZ2dnUU7-IGdnZ2d@giganews.com>
 <aa6a1985-c932-4e05-99e0-1ce47c29e6d0@googlegroups.com>
 <OIidnYnqF8UJDvfFnZ2dnUU7-SOdnZ2d@giganews.com>
Message-ID: <586B27B5.9040107@stoneleaf.us>

On 01/02/2017 09:53 AM, Wildman via Python-list wrote:

[rude ascii art omitted]

That is a completely inappropriate response.

--
~Ethan~


From python.list at tim.thechases.com  Mon Jan  2 23:26:16 2017
From: python.list at tim.thechases.com (Tim Chase)
Date: Tue, 03 Jan 2017 16:26:16 +1200
Subject: Clickable hyperlinks
Message-ID: <3265342128@f38.n261.z1.binkp.net>

On 2017-01-03 11:46, Deborah Swanson wrote:
> Excel has a formula:
>
> =HYPERLINK(url,description)
>
> that will put a clickable link into a cell.
>
> Does python have an equivalent function? Probably the most common
> use for it would be output to the console, similar to a print
> statement, but clickable.

Depends on what you're outputting.  In your context, you're creating content 
(and metadata) for a cell in an Excel workbook.

If that's the case you might have to use something like the xlwt module to 
create an Excel-style worksheet and adjust the properties of the cell to 
include the hyperlink property.

Or you can write out a .csv file with a hyperlink in a cell, which I believe 
Excel can interpret as a hyperlink.

Or write an HTML document with the corresponding HTML <a> tag in it.

Or you can just print it to stdout as normal as some terminals detect them and 
auto-linkify them.

But you have to specify where you want this link to appear to know how to solve 
the problem.

-tkc



From cr2001 at hotmail.co.nz  Mon Jan  2 23:27:32 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 03 Jan 2017 16:27:32 +1200
Subject: Hey, I'm new to python so don't judge.
References: <1279173106@f38.n261.z1.binkp.net>
Message-ID: <306187502@f38.n261.z1.binkp.net>

On Wednesday, January 4, 2017 at 1:17:11 PM UTC+13, Chris Angelico wrote:
> On Wed, Jan 4, 2017 at 11:03 AM, Erik <python at lucidity.plus.com> wrote:
> > I doubt it's getting that far (I can see at least one syntax error in the
> > code pasted).
>
> True true. In any case, the point is to copy and paste the error
> message. Callum, please, copy and paste it.
>
> ChrisA

I'm sorry if I'm doing something wrong but all that is happening is when i try 
to run it a popup says Invalid syntax



From cr2001 at hotmail.co.nz  Mon Jan  2 23:30:52 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 03 Jan 2017 16:30:52 +1200
Subject: Hey, I'm new to python so don't judge.
References: <1486132539@f38.n261.z1.binkp.net>
Message-ID: <320478962@f38.n261.z1.binkp.net>

On Wednesday, January 4, 2017 at 1:26:26 PM UTC+13, Erik wrote:
> Hi Callum,
>
> On 04/01/17 00:02, Callum Robinson wrote:
>  > When i check the code it comes up with invalid syntax and my writing
> line gets re directed here
>  >
>  > def is_same(target, number:
>  >         if target == number:
>  >             result="win"
>  >         elif target > number:
>  >             result="low"
>  >         else:
>  >             result="high"
>  >         return result
>
> OK, good. That implies it's something wrong with the function definition
> ('def'). Look at that very carefully :)   (*)
>
> E.
>
> (*) My emoticon may give you a hint ...

I feel like im missing something so blatantly obvious.



From cr2001 at hotmail.co.nz  Mon Jan  2 23:32:40 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 03 Jan 2017 16:32:40 +1200
Subject: Hey, I'm new to python so don't judge.
References: <1486132539@f38.n261.z1.binkp.net>
Message-ID: <2895515730@f38.n261.z1.binkp.net>

On Wednesday, January 4, 2017 at 1:26:26 PM UTC+13, Erik wrote:
> Hi Callum,
>
> On 04/01/17 00:02, Callum Robinson wrote:
>  > When i check the code it comes up with invalid syntax and my writing
> line gets re directed here
>  >
>  > def is_same(target, number:
>  >         if target == number:
>  >             result="win"
>  >         elif target > number:
>  >             result="low"
>  >         else:
>  >             result="high"
>  >         return result
>
> OK, good. That implies it's something wrong with the function definition
> ('def'). Look at that very carefully :)   (*)
>
> E.
>
> (*) My emoticon may give you a hint ...

I forgot a bloody bracket xD

and now theirs a new error ill try to figure this out on my own.



From tjreedy at udel.edu  Mon Jan  2 23:48:48 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Tue, 03 Jan 2017 16:48:48 +1200
Subject: pip install -r requirements.txt fails with Python 3.6 on Windows
Message-ID: <2091819101@f38.n261.z1.binkp.net>

On 1/3/2017 3:07 PM, Uri Even-Chen wrote:
> What are the reasons to upgrade Python to 3.6?

The same as for any new version:
New features  -- see What's New in 3.6. New bug fixes.
New performance improvements.

Reasons against:
The effort to make sure all dependencies are available for 3.6* Possible 
regressions.

* For Windows, any of the 381 wheels available from
http://www.lfd.uci.edu/~gohlke/pythonlibs/
should be available in 3.6 versions (unless there was a major problem in 
recompiling).

--
Terry Jan Reedy



From python at deborahswanson.net  Mon Jan  2 23:50:02 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 16:50:02 +1200
Subject: Clickable hyperlinks
Message-ID: <2264884113@f38.n261.z1.binkp.net>

Erik wrote, on January 03, 2017 3:30 PM
> To: python-list at python.org
> Subject: Re: Clickable hyperlinks
>
> Hi.
>
> On 03/01/17 19:46, Deborah Swanson wrote:
> > Excel has a formula:
>
> When you start a new topic on the list, could you please write a new
> message rather than replying to an existing message and changing the
> title/subject?
>
> For those reading the list in a threaded email client, this
> message is
> shown as a continuation of your "Cleaning up conditionals"
> thread, and
> that whole thread in turn shows up as a continuation of the "mentor
> training python Romania with certification" discussion (which you had
> presumably "reply"ed to originally) ...
>
> Thanks. E.

Certainly. I've been on many other lists before (but none since about 2011), 
and no one complained of or even mentioned this problem. But if it's a problem 
with some email readers now, I can easily just start a new message.  Just being 
lazy and following old habits, I guess. ;)



From tjreedy at udel.edu  Mon Jan  2 23:57:52 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Tue, 03 Jan 2017 16:57:52 +1200
Subject: Screwing Up looping in Generator
Message-ID: <612772844@f38.n261.z1.binkp.net>

On 1/3/2017 3:53 PM, Deborah Swanson wrote:

>> I think you're expecting
>>
>>      for file in rootobs
>>
>> to get the next yield for you from rootobs, but unless
>> someone corrects me, I don't think you can expect a 'for'
>> statement to do that. You need to have a 'next' statement
>> inside your for loop to get the next yield from the generator.

As I read this, out of context, it is wrong.  It it very unusual to call next 
on the current iterator (here next(rootobs)), inside a for loop.

> You probably want something like :
>
> for f in rootobs:
>     file = next

This is definitely wrong, as it makes 'find' an alias for the next() function.

>     base = os.path.basename(file.name)

and file.name will be an AttributeError.

-+-
If one wants to iterate through files and lines within files, which I believe I 
saw in this thread, one should have a for loop within a for loop.

--
Terry Jan Reedy



From python at deborahswanson.net  Tue Jan  3 00:01:18 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 17:01:18 +1200
Subject: Screwing Up looping in Generator
Message-ID: <1029216183@f38.n261.z1.binkp.net>

Erik wrote, on January 03, 2017 3:45 PM
>
> Hi,
>
> On 03/01/17 22:14, Deborah Swanson wrote:
> > ...you have to create the generator object first and use it to call
> > the next function. And I really don't think you can use a
> generator as
> > your range in a for loop. So I'd use a 'while True', and
> break out of
> > the loop when you hit the StopIteration exception:
> >
> > files = rootobs()
> >
> > while True:
> >   try:
> >     file = files.next()
> >   except StopIteration:
> >     break
> >
> >     base = os.path.basename(file.name)
> >        .
> >        .
> >        .
> >       (etc)
>
> What you have done there is taken an understanding of the underlying
> machinery that allows the 'for' loop to be syntactic sugar over any
> iterable and spelled it out, instead of just using 'for'! Without all
> that, your example is:
>
> for file in rootobs():
>    base = os.path.basename(file.name)
>    .
>    .
>    .
>    (etc)
>
> [In fact, the machinery would also cope with the return value from
> rootobs() being an iterable but not an iterator by using "files =
> iter(rootobjs)"].
>
>
>
> You seem to be reading up on how the stuff works under the
> covers (i.e.,
> from the point of view of an implementer of a class or
> library) and then
> suggesting that that's what the *caller* of that class or
> library needs
> to do. They don't - for a caller, 'for x in seq:' is all they need to
> know - the mechanics are handled by the interpreter coupled with the
> dunder methods that the class may implement.
>
>
> E.

Ok, I'm in complete agreement with everything you said up to the last 
paragraph, which I don't disagree with, I just don't see your point.

If you've read my last few posts you'll have seen me acknowledging that 
normally a for loop is used, but a while and break on StopIteration is a method 
that's useful when the output of the generator is unknown.

I haven't read through much documentation on generators, but I have taken a 
course from MIT, in which a Computer Science professor gave us several methods 
for working with generators, of which the while and break on StopIteration 
method is one.  The original poster wanted to use a while, and seemed to be 
saying he didn't know how many files the generator he has would yield, so that 
was why I recommended the while loop. Normally I would use a for loop too. D.



From cr2001 at hotmail.co.nz  Tue Jan  3 00:04:28 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 03 Jan 2017 17:04:28 +1200
Subject: Hey, I'm new to python so don't judge.
References: <2189830552@f38.n261.z1.binkp.net>
Message-ID: <4092501290@f38.n261.z1.binkp.net>

On Wednesday, January 4, 2017 at 1:45:22 PM UTC+13, Erik wrote:
> Hi Callum,
>
> On 04/01/17 00:30, Callum Robinson wrote:
> > I feel like im missing something so blatantly obvious.
>
> That's because you are ;). I don't want to come across as patronising,
> but I want you to see it for yourself, so, here's a function definition
> similar to yours that doesn't have the same syntax error that yours does:
>
> def foo(spam, ham):
>      if spam == ham:
>          return "same"
>      return "different"
>
> See the difference?
>
> E.

I've figured out that out but I have a new issue. I like what you are doing 
making me figure this out as it helps me remember. I'll post the new code and 
the issue. If you could give me a hint that would be great.

------------------------------------------
Issue
------------------------------------------

Traceback (most recent call last):
  File "D:/Python/random.py", line 6, in <module>
    computer_number = number.randint(1, 100)
NameError: name 'number' is not defined


-----------------------------------------
Here is the most recent code
-----------------------------------------


# mynumber.py
# this game uses a home made function
import random

#think of a number
computer_number = number.randint(1, 100)

#create the function is_same()
def is_same(target, number):
        if target == number:
            result="Win"
        elif target > number:
            result="Low"
        else:
            result="High"
        return result

# start the game
print("hello. \nI have thought of a number between 1 and 100.")

#collect the user's guess as an interger
guess = int(input("Can you guess it? "))
#Use our function
higher_or_lower = is_same(computer_number, guess)
#run the game untill the user is correct
while higher_or_lower != "win":
    if higher_or_lower == "low":
         guess = int(input("Sorry, you are too low. Try again."))
    else:
        guess = int(input("Sorry your are too high. Try again."))

    higher_or_lower = is_same(computer_number, guess)

#end of game
input("Correct!\nWell Done\n\n\nPress RETURN to exit.")



From python at deborahswanson.net  Tue Jan  3 00:12:22 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 17:12:22 +1200
Subject: Screwing Up looping in Generator
Message-ID: <186423320@f38.n261.z1.binkp.net>

Erik wrote, on January 03, 2017 3:53 PM
>
> On 03/01/17 23:05, Deborah Swanson wrote:
> > And yes, we usually used for loops for generators, unless you don't
> > know when the generator will be exhausted. As in this case,
> where the
> > number of files the generator can provide is unknown. Then
> we used the
> > while True, break on StopIteration method.
>
> Out of interest, *why* was it deemed necessary to do
> something different
> if you don't know how many items the generator will generate? Was any
> rationale given for that?
>
> for x in foo:
>    bar(x)
>
> ... where foo is any iterable (something that has a __iter__ method
> defined - including generators) will just bind each value in
> turn to 'x'
> and will exit when the StopIteration exception is raised under the
> covers by the iterator that is iterating over the iterable.
>
> Some generators are infinite (and their iterator will never raise a
> StopIteration exception).
>
> E.

The main reason you might want to catch the StopIteration exception is to do 
something else before your code simply stops running. If all you're doing is 
run a generator til it's out of gas, and that's all you want it to do, then 
there's no need to catch anything. There's lots of situations where this is 
exactly what you want. It might even be the most frequent use of generators, 
though I wouldn't know.



From tonycamgar at gmail.com  Tue Jan  3 00:15:47 2017
From: tonycamgar at gmail.com (Antonio Caminero Garcia)
Date: Mon, 2 Jan 2017 21:15:47 -0800 (PST)
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <586b0517$0$1584$c3e8da3$5496439d@news.astraweb.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
 <586b0517$0$1584$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <2b56d5b8-7cef-4efd-80d9-1d25a50c3f95@googlegroups.com>

On Monday, January 2, 2017 at 5:57:51 PM UTC-8, Steve D'Aprano wrote:
> On Mon, 2 Jan 2017 10:38 pm, Antonio Caminero Garcia wrote:
> 
> > Hello, I am having a hard time deciding what IDE or IDE-like code editor
> > should I use. This can be overwhelming.
> 
> Linux is my IDE.
> 
> https://sanctum.geek.nz/arabesque/series/unix-as-ide/
> 
> 
> I dislike the Unix-style Vim/Emacs text editors, I prefer a traditional
> GUI-based editor. So my "IDE" is:
> 
> - Firefox, for doing searches and looking up documentation;
> 
> - an GUI programmer's editor, preferably one with a tab-based 
>   interface, such as geany or kate;
> 
> - a tab-based terminal.
> 
> Both geany and kate offer auto-completion based on previously seen words.
> They won't auto-complete function or method signatures, but in my my
> experience this is the "ninety percent" solution: word-based auto-complete
> provides 90% of the auto-complete functionality without the cost of full
> signature-based auto-complete.
> 
> In the terminal, I have at least three tabs open: one open to the Python
> interactive interpreter, for testing code snippets and help(obj); one where
> I run my unit tests ("python -m unittest myproject_tests"); and one where I
> do any assorted other tasks, such as file management, checking code into
> the repo, etc.
> 
> I've played with mypy a few times, but not used it seriously in any
> projects. If I did, I would run that from the command line too, like the
> unit tests. Likewise for any linters or equivalent.
> 
> 
> > So far, I have used Vim, Sublime, Atom, Eclipse with PyDev, Pycharm,
> > IntelliJ with Python plugin.
> > 
> > The thing with the from-the-scratch full featured IDEs (Eclipse, IntelliJ,
> > Pycharm) is that they look like a space craft dashboard and that
> > unwarranted resources consumption and the unnecessary icons. 
> 
> Indeed. If they provide any useful functionality I don't already have, I've
> never come across it. The only thing I'd like to try is an editor that
> offers semantic highlighting instead of syntax highlighting:
> 
> https://medium.com/@evnbr/coding-in-color-3a6db2743a1e
> 
> I once tried Spyder as an IDE, and found that it was so bloated and slow it
> couldn't even keep up with my typing. I'm not even a touch typist! I'd
> start to type a line like:
> 
>     except ValueError as err:
> 
> 
> and by the time my fingers were hitting the colon, Spyder was displaying
> `excep` in red flagged with an icon indicating a syntax error.
> 
> 
> 
> 
> -- 
> Steve
> ?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
> enough, things got worse.

Thanks for remind the Unix capabilities as IDE, that post was cool to read.


From cr2001 at hotmail.co.nz  Tue Jan  3 00:25:12 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 03 Jan 2017 17:25:12 +1200
Subject: Hey, I'm new to python so don't judge.
References: <3844402364@f38.n261.z1.binkp.net>
Message-ID: <637094488@f38.n261.z1.binkp.net>

On Wednesday, January 4, 2017 at 2:16:08 PM UTC+13, Steve D'Aprano wrote:
> On Wed, 4 Jan 2017 12:04 pm, Callum Robinson wrote:
>
> > Traceback (most recent call last):
> >   File "D:/Python/random.py", line 6, in <module>
> >     computer_number = number.randint(1, 100)
> > NameError: name 'number' is not defined
>
>
> That's exactly what we need to see! The full traceback, thank you!
>
> You're asking Python to get the variable "number", and call the randint
> method. But:
>
> - you don't have a variable called "number";
>
> NameError: name 'number' is not defined
>
>
> - and even if you did, that's not how you get a random number. What you want
> is:
>
> computer_number = random.randint(1, 100)
>
>
>
>
>
>
> --
> Steve
> ? ?Cheer up,? ? they said, ? ?things could be worse.? ? So I cheered up, and
sure
> enough, things got worse.

Hey man thanks, the sad thing is i have no idea why i put that in. I must be 
having a terrible day.



From flebber.crue at gmail.com  Tue Jan  3 00:35:58 2017
From: flebber.crue at gmail.com (Sayth Renshaw)
Date: Tue, 03 Jan 2017 17:35:58 +1200
Subject: Screwing Up looping in Generator
References: <3009695678@f38.n261.z1.binkp.net>
Message-ID: <393525457@f38.n261.z1.binkp.net>

So can I call the generator twice and receive the same file twice in 2 for 
loops?

Once to get the files name and the second to process?

 for file in rootobs:
        base = os.path.basename(file.name)
        write_to = os.path.join("output", os.path.splitext(base)[0] + ".csv")
        with open(write_to, 'w', newline='') as csvf:
            for file in rootobs:
              # create and write csv

Cheers

Sayth



From cr2001 at hotmail.co.nz  Tue Jan  3 00:37:24 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 03 Jan 2017 17:37:24 +1200
Subject: Hey, I'm new to python so don't judge.
References: <1223999572@f38.n261.z1.binkp.net>
Message-ID: <4260468770@f38.n261.z1.binkp.net>

On Wednesday, January 4, 2017 at 12:49:28 PM UTC+13, Callum Robinson wrote:
> Im doing a new task from my teacher but i can't seem to find what is wrong
with this code. Can anyone help?
>
> #mynumber.py
> # this game uses a home made function
> import random
>
> #think of a number
> computer_number = number.randint(1,100)
>
> #create the function is_same()
> def is_same(target, number:
>         if target == number:
>             result="win"
>         elif target > number:
>             result="low"
>         else:
>             result="high"
>         return result
>
> # start the game
> print("hello. \nI have thought of a number between 1 and 100.")
>
> #collect the user's guess as an interger
> guess = int(input("Can you guess it? "))
> #Use our function
> higher_or_lower = is_same(computer_number, guess)
> #run the game untill the user is correct
> while higher_or_lower != "win"
>     if higher_or_lower == "to low"
>          guess = int(input("Sorry, you are too low. Try again."))
>     else:
>         guess = int(input("Sorry your are too high. Try again."))
>
>     higher_or_lower = is_same(computer_number, guess)
>
> #end of game
> input("Correct!\nWell Done\n\n\nPress RETURN to exit.")

Hey again, i'm sorry for bothering you with so many questions i just did not 
want to keep asking my teacher who is on holiday these.

I have another issue where the code runs but i can guess every number from 
1-100 but it always says Sorry your are too high. Try again. I don't understand 
what i have done to cause this.



From tonycamgar at gmail.com  Tue Jan  3 00:42:40 2017
From: tonycamgar at gmail.com (Antonio Caminero Garcia)
Date: Mon, 2 Jan 2017 21:42:40 -0800 (PST)
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
Message-ID: <ba923722-087d-4c13-aaf6-0950a370c27b@googlegroups.com>

Guys really thank you for your answers. Basically now I am more emphasizing in learning in depth a tool and get stick to it so I can get a fast workflow. Eventually I will learn Vim and its python developing setup, I know people who have been programming using Vim for almost 20 years and they did not need to change editor (that is really awesome). 


From flebber.crue at gmail.com  Tue Jan  3 00:54:34 2017
From: flebber.crue at gmail.com (Sayth Renshaw)
Date: Tue, 03 Jan 2017 17:54:34 +1200
Subject: Screwing Up looping in Generator
References: <393525457@f38.n261.z1.binkp.net>
Message-ID: <650696286@f38.n261.z1.binkp.net>

On Wednesday, 4 January 2017 12:36:10 UTC+11, Sayth Renshaw  wrote:
> So can I call the generator twice and receive the same file twice in 2 for
loops?
>
> Once to get the files name and the second to process?
>
>  for file in rootobs:
>         base = os.path.basename(file.name)
>         write_to = os.path.join("output", os.path.splitext(base)[0] + ".csv")
>         with open(write_to, 'w', newline='') as csvf:
>             for file in rootobs:
>               # create and write csv
>
> Cheers
>
> Sayth

I just need it to write after each file however the

with open(#file) as csvf:

Keeps it all open until every file processed in an output file with the name of 
the first file in the generator.

Sayth



From python at deborahswanson.net  Tue Jan  3 01:05:12 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 18:05:12 +1200
Subject: Screwing Up looping in Generator
Message-ID: <3212211156@f38.n261.z1.binkp.net>

Chris Angelico wrote, on January 03, 2017 3:35 PM
>
> On Wed, Jan 4, 2017 at 10:05 AM, Deborah Swanson
> <python at deborahswanson.net> wrote:
> > Ok, I learned how to use generators in Python 2.7.8, which may be
> > different from Python 3 for generators. But I learned from MIT's
> > online introduction to python course, and they certainly
> seem to know
> > python well. So what is the correct way to call the
> generator's next
> > yield in Python 3? We only learned to use the next function. If you
> > don't use the next function, what do you use?
>
> The built-in next function, not the next method.
>
> # don't do this
> gen.next()
>
> # do this
> next(gen)
>
> ChrisA

You speak the truth! I never doubted, but since I still have 2.7.8 on my system 
 I decided to try it out.

For a simple little Fibbonacci number generator:

def genFib ():
        fibn_1 = 1 #fib(n-1)
        fibn_2 = 0 #fib(n-2)
        while True:
                # fib(n) = fib(n-1) + fib(n-2)
                next = fibn_1 + fibn_2
                yield next
                fibn_2 = fibn_1
                fibn_1 = next

and at the console:

>>> fib = genFib()
>>> fib.next()

2.7.8 works, and cranks out as many Fibbonacci numbers as you could want.

But in 3.4.3 you get:

Traceback (most recent call last):
  File "<pyshell#13>", line 1, in <module>
    fib.next()
AttributeError: 'generator' object has no attribute 'next'

Then, going the other way, next(fib) works in both versions.



From flebber.crue at gmail.com  Tue Jan  3 01:09:34 2017
From: flebber.crue at gmail.com (Sayth Renshaw)
Date: Tue, 03 Jan 2017 18:09:34 +1200
Subject: Screwing Up looping in Generator
References: <650696286@f38.n261.z1.binkp.net>
Message-ID: <1791039168@f38.n261.z1.binkp.net>

Untested as i wrote this in notepad at work but, if i first use the generator 
to create a set of filenames and then iterate it then call the generator anew 
to process file may work?

Good idea or better available?

def get_list_of_names(generator_arg):
    name_set = set()
    for name in generator_arg:
        base = os.path.basename(name.name)
        filename = os.path.splitext(base)[0]
        name_set.add(filename)
    return name_set



 for file_name in name_set:
     directory = "output"
         with open(os.path.join(directory, filename, 'w', newline='') as csvf:
            for file in rootobs:
              # create and write csv

Sayth



From python at deborahswanson.net  Tue Jan  3 01:10:16 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 18:10:16 +1200
Subject: Screwing Up looping in Generator
Message-ID: <152304910@f38.n261.z1.binkp.net>

Sayth Renshaw wrote, on January 03, 2017 5:36 PM
>
> So can I call the generator twice and receive the same file
> twice in 2 for loops?
>
> Once to get the files name and the second to process?
>
>  for file in rootobs:
>         base = os.path.basename(file.name)
>         write_to = os.path.join("output",
> os.path.splitext(base)[0] + ".csv")
>         with open(write_to, 'w', newline='') as csvf:
>             for file in rootobs:
>               # create and write csv
>
> Cheers
>
> Sayth

I don't see why not, if you let the first one run to completion and then do it 
again a second time. Assuming your generator doesn't somehow delete or modify 
the file specifications as it yields them. It would be helpful to see the code 
for rootobs, if you have it. D.



From python at deborahswanson.net  Tue Jan  3 01:21:58 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 18:21:58 +1200
Subject: Screwing Up looping in Generator
Message-ID: <1429338932@f38.n261.z1.binkp.net>

Sayth Renshaw wrote, on January 03, 2017 5:55 PM
>
> On Wednesday, 4 January 2017 12:36:10 UTC+11, Sayth Renshaw  wrote:
> > So can I call the generator twice and receive the same file
> twice in 2
> > for loops?
> >
> > Once to get the files name and the second to process?
> >
> >  for file in rootobs:
> >         base = os.path.basename(file.name)
> >         write_to = os.path.join("output",
> os.path.splitext(base)[0] + ".csv")
> >         with open(write_to, 'w', newline='') as csvf:
> >             for file in rootobs:
> >               # create and write csv
> >
> > Cheers
> >
> > Sayth
>
> I just need it to write after each file however the
>
> with open(#file) as csvf:
>
> Keeps it all open until every file processed in an output
> file with the name of the first file in the generator.
>

In that case, I think you just need to devise your output file name scheme, and 
it looks like you want to use 'os.path.splitext(base)[0] + ".csv")'. Then  
output each file in the same for loop, before you go back for another input 
file. Just read in the file, do whatever you want to it, and then write it to 
the new file name, all in the same loop.

I don't see any need to loop through rootobs a second time.



From torriem at gmail.com  Tue Jan  3 01:22:58 2017
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 03 Jan 2017 18:22:58 +1200
Subject: Clickable hyperlinks
Message-ID: <1685359403@f38.n261.z1.binkp.net>

On 01/03/2017 04:32 PM, Deborah Swanson wrote:
> The GUI consoles I have are in Pycharm, the IDLE that comes with
> Anaconda, and Spyder. PyCharm and IDLE both ask for internet access when
> I open them, so they're capable of opening links, but whether that means
> their output space is capable of handling clickable links I don't know.

Hmm I still don't understand what you mean by "GUI console."  Just because a 
program asks for internet access does not mean anything about whether or not 
your python program can display a clickable link in a console window.  Besides 
that, a clickable link would probably ask the OS to open it with the default 
application, not cause your program to access the internet.

The standard out pipe (where stuff goes when you call print() or write to 
sys.stdout) from a python program usually goes to a console or a terminal 
emulator.  PyCharm and IDLE both provide windows to display this output (they 
emulate a terminal). But maybe you're misunderstanding what this actually is.  
These windows just display a stream of bytes that come out of your program.  
Certain escape codes can be emitted that can instruct the console or terminal 
emulator to do things like set text color or display text at a certain 
position. But there's certainly no special way to instruct the terminal 
emulator to make a section of text into a hyperlink.  Maybe if hyperlinks had 
existed years ago when terminal escape codes were being defined we'd have a 
"hyperlink" code that all consoles and terminals would understand.  A few years 
ago I saw some proposals to add an escape code to the ANSI scheme that would 
encode hyperlinks, but nothing ever came of it because, honestly, it would be 
too much hassle to roll this out to ever terminal emulator out there (to say 
nothing of real terminals).

> I do know printing a full url with the %s specifier or entering a url
> and clicking enter just gives you the plain text url. Obviously, not all
> GUI consoles are enabled recognize and make clickable links from
> correctly formatted urls.

On my Linux machine, the terminal emulators I've used all make a regular url 
printed out into a clickable link (or at least a right-clickable link).  This 
is just something they try to do with all things that look like urls.  
Sometimes it's helpful, often it's annoying.

> I was hoping there was some functionality in python to make clickable
> links. Could be a package, if the core language doesn't have it.

No, there is not.  If you made a full GUI app using a toolkit like GTK or Qt, 
you can indeed place hyperlinks on your forms and the operating system will 
automatically connect them to the web browser.  But not in text-mode terminal 
apps.



From cr2001 at hotmail.co.nz  Tue Jan  3 01:24:16 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 03 Jan 2017 18:24:16 +1200
Subject: Hey, I'm new to python so don't judge.
References: <3183934424@f38.n261.z1.binkp.net>
Message-ID: <802561195@f38.n261.z1.binkp.net>

On Wednesday, January 4, 2017 at 3:05:48 PM UTC+13, MRAB wrote:
> On 2017-01-04 01:37, Callum Robinson wrote:
> > On Wednesday, January 4, 2017 at 12:49:28 PM UTC+13, Callum Robinson wrote:
> >> Im doing a new task from my teacher but i can't seem to find what is wrong
with this code. Can anyone help?
> >>
> >> #mynumber.py
> >> # this game uses a home made function
> >> import random
> >>
> >> #think of a number
> >> computer_number = number.randint(1,100)
> >>
> >> #create the function is_same()
> >> def is_same(target, number:
> >>         if target == number:
> >>             result="win"
> >>         elif target > number:
> >>             result="low"
> >>         else:
> >>             result="high"
> >>         return result
> >>
> >> # start the game
> >> print("hello. \nI have thought of a number between 1 and 100.")
> >>
> >> #collect the user's guess as an interger
> >> guess = int(input("Can you guess it? "))
> >> #Use our function
> >> higher_or_lower = is_same(computer_number, guess)
> >> #run the game untill the user is correct
> >> while higher_or_lower != "win"
> >>     if higher_or_lower == "to low"
> >>          guess = int(input("Sorry, you are too low. Try again."))
> >>     else:
> >>         guess = int(input("Sorry your are too high. Try again."))
> >>
> >>     higher_or_lower = is_same(computer_number, guess)
> >>
> >> #end of game
> >> input("Correct!\nWell Done\n\n\nPress RETURN to exit.")
> >
> > Hey again, i'm sorry for bothering you with so many questions i just did
not want to keep asking my teacher who is on holiday these.
> >
> > I have another issue where the code runs but i can guess every number from
1-100 but it always says Sorry your are too high. Try again. I don't understand 
what i have done to cause this.
> >
> What values can 'is_same' return?
>
> Which of those values are you checking for in the loop?

I'm sorry but i do not completely understand what you are stating



From cs at zip.com.au  Tue Jan  3 01:39:03 2017
From: cs at zip.com.au (Cameron Simpson)
Date: Tue, 3 Jan 2017 17:39:03 +1100
Subject: trouble with cmd.Cmd and prompting
In-Reply-To: <v7cm6chmd32it422kh3doh6a6k6d1inq4n@4ax.com>
References: <v7cm6chmd32it422kh3doh6a6k6d1inq4n@4ax.com>
Message-ID: <20170103063903.GA63893@cskk.homeip.net>

On 03Jan2017 00:14, Dennis Lee Bieber <wlfraed at ix.netcom.com> wrote:
>On Tue, 3 Jan 2017 11:33:15 +1100, Cameron Simpson <cs at zip.com.au>
>declaimed the following:
>>I'm using cmd.Cmd to write a little FTP-like command line to interface to a
>>storage system of mine and encountering weird behaviour. When I enter a command
>>the next prompt appears _before_ the associated operation runs, or so it
>>appears.
>	<SNIP>
>>Has anyone seen this kind of thing before?
>
>	Haven't used the module but there is something I find intriguing in the
>help system
>-=-=-=-=-
> Cmd.precmd(line)
>    Hook method executed just before the command line is interpreted, but
>after the input prompt is generated and issued.
>-=-=-=-=-
>"... AFTER the input prompt is ... issued"
>
>	I don't know, but that sure sounds to me like the cmd object tends to
>process one line behind... Though that behavior is not shown in the turtle
>example in the help system.

Hmm. Interesting. I had read that text to imply (based on what I imagined 
_should_ happen) that the flow of control went:

  cmdloop:
    issue prompt>
    line=input()  # or readline
    line=precmd(line)
    stop=onecmd(line) # which calls do_blah...
    stop=postcmd(stop,line)
    if stop:
      break

but your reading of it suggests that this is possible:

  issue prompt>
  cmdloop:
    line=input()  # or readline
    issue prompt>
    line=precmd(line)
    stop=onecmd(line) # which calls do_blah...
    stop=postcmd(stop,line)
    if stop:
      break

The text for Cmd.cmdloop starts with this:

  Repeatedly issue a prompt, accept input, parse an initial prefix off the 
  received input, and dispatch to action methods, passing them the remainder of 
  the line as argument.

which argues for the former, and was what I naively expected.

I guess I'd better dig out the source; I dislike going that far, not merely out 
of laziness, but also because the source is not the spec.

Thanks for the suggestion,
Cameron Simpson <cs at zip.com.au>


From python at deborahswanson.net  Tue Jan  3 01:40:14 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 18:40:14 +1200
Subject: Screwing Up looping in Generator
Message-ID: <796810093@f38.n261.z1.binkp.net>

Erik wrote, on January 03, 2017 5:26 PM
> Hi,
>
> On 04/01/17 01:12, Deborah Swanson wrote:
> > The main reason you might want to catch the StopIteration
> exception is
> > to do something else before your code simply stops running. If all
> > you're doing is run a generator til it's out of gas, and that's all
> > you want it to do, then there's no need to catch anything.
>
> Ah! OK, I see where the lines are being crossed now ;) Although
> StopIteration is an exception, it is something that the 'for/iter'
> machinery handles for you under the covers. Each 'for' statement
> effectively has a 'try' block around it that catches
> 'StopIteration' and
> just terminates that particular 'for' loop and continues on with the
> remainder of your script.
>
> Raising a 'StopIteration' is an internal mechanism used to determine
> when an iterator (i.e., the thing a 'for' loop is looping over) has
> exhausted itself. It's not something a regular user is ever
> expected to
> know about let alone catch.
>
> When execution falls out of the bottom of a generator,
> StopIteration is
> raise (compared to a regular function or method returning 'None').
>
> E.

Looks like those MIT professors knew what they were teaching us after all! 
Sneaky, but they never once hinted that this was any deep dark secret. Just a 
way to deal with generators that will stop after a finite and unknown number of 
yields, and you want your code to keep going after the generator quits. I 
thought I was just regurgitating a standard approach, and surprised to get so 
much push back on it.

Seems like python uses a lot of its external functionality (what we normally 
code with) for internal behavior too. In this case, and for empty returns, 
they're raising exceptions, catching them and then doing what they want to. I 
suppose, if you don't want the method returning None, you could catch that 
exception and return something else. Or return nothing at all, which is what I 
usually want to do when those pesky Nones crop up.  But I'm not entirely sure 
how you would make it return nothing at all.



From cr2001 at hotmail.co.nz  Tue Jan  3 01:47:42 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 03 Jan 2017 18:47:42 +1200
Subject: Hey, I'm new to python so don't judge.
References: <595817138@f38.n261.z1.binkp.net>
Message-ID: <1642603984@f38.n261.z1.binkp.net>

On Wednesday, January 4, 2017 at 3:35:53 PM UTC+13, Erik wrote:
> On 04/01/17 02:24, Callum Robinson wrote:
> > On Wednesday, January 4, 2017 at 3:05:48 PM UTC+13, MRAB wrote:
> >> What values can 'is_same' return?
> >>
> >> Which of those values are you checking for in the loop?
> >
> > I'm sorry but i do not completely understand what you are stating
>
> You need to think about the specific things (their type, their exact
> values) that your functions might return. Printing some trace output is
> a classic way of debugging your program. If, after this line:
>
>  >>>> higher_or_lower = is_same(computer_number, guess)
>
> ... you added:
>
> print (higher_or_lower)
>
> ... what values do you then see being output? How will those values be
> processed by the conditions you see that work on the "higher_or_lower"
> variable?
>
> E.

I did it and this is what it states when i run it

hello.
I have thought of a number between 1 and 100. Can you guess it?
5
Low
Sorry , you are too high. Try again.

Does this mean the number i entered is to low but the code is still stating it 
is to high?



From rustompmody at gmail.com  Tue Jan  3 01:48:51 2017
From: rustompmody at gmail.com (Rustom Mody)
Date: Mon, 2 Jan 2017 22:48:51 -0800 (PST)
Subject: learning and experimenting python.
In-Reply-To: <mailman.137.1483417523.2395.python-list@python.org>
References: <6886d439-751c-42d2-adf2-fbf494221d48@googlegroups.com>
 <o47q7t$4jq$1@dont-email.me>
 <58678152$0$1622$c3e8da3$5496439d@news.astraweb.com>
 <d5a48cd6-fd0e-45eb-bac6-0bf7dc131250@googlegroups.com>
 <CALwzid=98ggNQiLNe0sVMbxN2wQ-zGecFvQf-DZ4_JRTjNZWuQ@mail.gmail.com>
 <o4beb3$8h4$1@blaine.gmane.org>
 <mailman.104.1483291835.2395.python-list@python.org>
 <c4d371a9-0d00-4a98-8daf-894811a9b72d@googlegroups.com>
 <W-GdnbGl-7FncPTFnZ2dnUU7-IGdnZ2d@giganews.com>
 <aa6a1985-c932-4e05-99e0-1ce47c29e6d0@googlegroups.com>
 <OIidnYnqF8UJDvfFnZ2dnUU7-SOdnZ2d@giganews.com>
 <586B27B5.9040107@stoneleaf.us>
 <mailman.137.1483417523.2395.python-list@python.org>
Message-ID: <72177ffd-b44b-484a-959e-722c79f6706f@googlegroups.com>

On Tuesday, January 3, 2017 at 9:55:35 AM UTC+5:30, Ethan Furman wrote:
> On 01/02/2017 09:53 AM, Wildman via Python-list wrote:
> 
> [rude ascii art omitted]
> 
> That is a completely inappropriate response.
> 
> --
> ~Ethan~

Besides
1. Without fix-pitch the ASCII art is undecipherable. [I assume the person in 
question posted from google groups so most likely he sees it in proportional]
2. He seems to have deleted his posts from GG
https://groups.google.com/forum/#!topic/comp.lang.python/KLdkUGOV5lU


From python at deborahswanson.net  Tue Jan  3 02:04:36 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 19:04:36 +1200
Subject: Clickable hyperlinks
Message-ID: <1619621956@f38.n261.z1.binkp.net>

Steve D'Aprano wrote, on January 03, 2017 4:56 PM

> On Wed, 4 Jan 2017 10:32 am, Deborah Swanson wrote:
>
>
> > The GUI consoles I have are in Pycharm, the IDLE that comes with
> > Anaconda, and Spyder. PyCharm and IDLE both ask for internet access
> > when I open them, so they're capable of opening links, but whether
> > that means their output space is capable of handling
> clickable links I
> > don't know.
> >
> > I do know printing a full url with the %s specifier or
> entering a url
> > and clicking enter just gives you the plain text url.
> Obviously, not
> > all GUI consoles are enabled recognize and make clickable
> links from
> > correctly formatted urls.
> >
> > I was hoping there was some functionality in python to make
> clickable
> > links. Could be a package, if the core language doesn't have it.
>
> Unfortunately there is no such thing as an application-
> independent "clickable link".

I'm getting that.

> Excel can make clickable links, because it only has to deal
> with a single suite of related applications: Excel, Word, and
> the rest of Microsoft Office. Likewise LibreOffice.
>
> But Python has to deal with an infinite number of potential
> or hypothetical consoles, and there is no standard for
> "clickable links" that all, or even most, consoles understand.
>
> Python can't force the console to treat something as a
> clickable link, if the console has no capacity for clickable
> links. Nor can Python predict what format the console uses to
> recognise a link.
>
> The best you can do is to experiment with a couple of simple
> formats and see which, if any, your console understands:
>
> # HTML
> <a href="http://www.example.com">Example.</a>
>
> # URL in angle brackets
> Example <http://www.example.com>
>
> # URL alone
> http://www.example.com
>
> # I can't remember what these are called <url:http://www.example.com>
>
> # Markup
> [Example](http://www.example.com)
>
> # Rest
> `Example <http://www.example.com>`_
>
>
>
>
>
> --
> Steve
> "Cheer up," they said, "things could be worse." So I cheered
> up, and sure enough, things got worse.

I tried all of your examples in IDLE, and they all get syntax errors. I'd 
expect the same from PyCharm, though I didn't try it.

I think I need to write a class to do it in a particular application, 
preferably in PyCharm, though I'd need some kind of internet access engine to 
do it anywhere. I can look up how Firefox does it, pretty sure I have that 
somewhere. Maybe there's a way...

Maybe it's a stupid idea, but originally I wanted to output links and click on 
them while I was still debugging in PyCharm, without having to save the csv and 
reopen it in Excel, to see what was in a listing* while I was still debugging. 
PyCharm does have links in its console output that take you to positions in the 
code when you click on them, so it seems like all the basic infrastructure is 
there. I just have to figure out how to do it for internet urls that I output.

* listing is a real estate listing with a url, part of a project I'm
working on, in case you haven't read the "Cleaning up conditionals" thread.



From python at deborahswanson.net  Tue Jan  3 02:35:31 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 2 Jan 2017 23:35:31 -0800
Subject: Cleaning up conditionals
In-Reply-To: <ed0lq6Fr91oU1@mid.individual.net>
Message-ID: <000401d26593$f7056710$27b23dae@sambora>

Gregory Ewing wrote, on January 02, 2017 7:58 PM
> 
> Deborah Swanson wrote:
> > Unless you know of, and are suggesting, a way to index a 
> sequence with 
> > strings instead of integers, so the code could remain 
> untouched with 
> > string indices when changes to the columns are made.
> 
> I'm talking about this:
> 
>https://docs.python.org/3/library/collections.html#collections.namedtup
le

>It's like a tuple, but the fields also have names, so
>you can access them like attributes using dot-notation.

> Also, for such a scheme to be superior to what I already have, it 
> needs to be very nearly self-maintaining.

>If you derive the attribute names from the header row,
>it would be extremely self-maintaining. You would be able
>to reorder columns without touching the code at all.

>-- 
>Greg

I've never worked with collections before, and you're the second person
on this thread to suggest using them. I'm very intrigued by both your
use of collections and Peter Otten's.

I think I'm right that core python sequences can't be indexed in any
fashion by strings, because strings aren't iterable. I suppose it might
be possible for strings to be iterable in some sort of ascii char code
order, but that seems like it could get real whacky very fast, and not
terribly useful.

But a library of functions designed to augment core python certainly
would be capable of many things.  So I will be checking out collections
and your suggested use of namedtuples very soon. I may not need to fix
this part of my code, but I would like to learn a new way to do it. And
it would be nice to replace the long string of 2-letter variables I
currently have with a data structure. They're not really in the way, but
they do clutter up the variable list in PyCharm. And using the header
row titles as indices would automatically make my code a lot more
readable.

Thanks!  ;)
D.



From python at deborahswanson.net  Tue Jan  3 02:46:44 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 19:46:44 +1200
Subject: Clickable hyperlinks
Message-ID: <3686502656@f38.n261.z1.binkp.net>

David wrote, on January 03, 2017 6:36 PM
>
> On 4 January 2017 at 11:50, Deborah Swanson
> <python at deborahswanson.net> wrote:
> > Erik wrote, on January 03, 2017 3:30 PM
> >>
> >> When you start a new topic on the list, could you please
> write a new
> >> message rather than replying to an existing message and
> changing the
> >> title/subject?
> >>
> > Certainly. I've been on many other lists before (but none
> since about
> > 2011), and no one complained of or even mentioned this
> problem. But if
> > it's a problem with some email readers now, I can easily
> just start a
> > new message.  Just being lazy and following old habits, I guess. ;)
>
> To be clear, the problem is not "with some email readers".

Actually it is, or at least it doesn't happen in all email readers. Mine, for 
instance, never breaks up threads.

> The problem is that it breaks the thread management features
> that are built into every email message, making it impossible
> to display threads correctly.

Again, I think this is in some modern email readers. Apparently older ones were 
more robust.

> As can be seen here for example:
> https://mail.python.org/pipermail/python->
list/2017-January/thread.html
>
> Note how most threads start in the leftmost column and
> replies are indented. But this does not occur where you began
> the new subject: "Clickable hyperlinks".

Yes, pipermail does seem to have a few bugs, this is the second one I've seen.

> Thanks.

I did say in the message you're replying to that I will try to remember to 
start new threads with brand new messages. (Even though I think pipermail's 
behavior is a bug, that's what many people read the list from.)



From wlfraed at ix.netcom.com  Tue Jan  3 02:59:08 2017
From: wlfraed at ix.netcom.com (Dennis Lee Bieber)
Date: Tue, 03 Jan 2017 19:59:08 +1200
Subject: Hey, I'm new to python so don't judge.
Message-ID: <2068038870@f38.n261.z1.binkp.net>

On Tue, 3 Jan 2017 16:02:15 -0800 (PST), Callum Robinson
<cr2001 at hotmail.co.nz> declaimed the following:

>When i check the code it comes up with invalid syntax and my writing line gets
re directed here
>
>def is_same(target, number:
>        if target == number:
>            result="win"
>        elif target > number:
>            result="low"
>        else:
>            result="high"
>        return result

        Count your parentheses... You should have the same number of ) as you
have (

--
        Wulfraed                 Dennis Lee Bieber         AF6VN
    wlfraed at ix.netcom.com    HTTP://wlfraed.home.netcom.com/



From tjreedy at udel.edu  Tue Jan  3 03:06:18 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Tue, 03 Jan 2017 20:06:18 +1200
Subject: Hey, I'm new to python so don't judge.
Message-ID: <105591444@f38.n261.z1.binkp.net>

On 1/3/2017 7:02 PM, Callum Robinson wrote:
> When i check the code it comes up with invalid syntax and my writing line
gets re directed here
>
> def is_same(target, number:
>         if target == number:
>             result="win"
>         elif target > number:
>             result="low"
>         else:
>             result="high"
>         return result

When I paste this into a file in IDLE and try to run the file, 'if' is 
highlighted in red.  This means that there is an error somewhere at or before 
the 'if'.


--
Terry Jan Reedy



From rosuav at gmail.com  Tue Jan  3 03:14:10 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 3 Jan 2017 19:14:10 +1100
Subject: Cleaning up conditionals
In-Reply-To: <000401d26593$f7056710$27b23dae@sambora>
References: <ed0lq6Fr91oU1@mid.individual.net>
 <000401d26593$f7056710$27b23dae@sambora>
Message-ID: <CAPTjJmqC8oPpceQgpuMxMw64tfZ5aE91S1kjFnkeKax6RevgeA@mail.gmail.com>

On Tue, Jan 3, 2017 at 6:35 PM, Deborah Swanson
<python at deborahswanson.net> wrote:
> I think I'm right that core python sequences can't be indexed in any
> fashion by strings, because strings aren't iterable. I suppose it might
> be possible for strings to be iterable in some sort of ascii char code
> order, but that seems like it could get real whacky very fast, and not
> terribly useful.

It's not because they're not iterable, but because there's a
fundamental difference between a key-value pair (dict) and a sequence.
You can combine the two in several different ways, none of which is
the "one most obvious". Python's OrderedDict retains the order of its
keys; in contrast, a namedtuple is a "record" type with a fixed set of
keys that correspond to positions in the record. In your case, I think
a namedtuple would be a good fit, but there's no general concept of
indexing a sequence with strings.

ChrisA


From python at deborahswanson.net  Tue Jan  3 03:46:30 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 03 Jan 2017 20:46:30 +1200
Subject: Clickable hyperlinks
Message-ID: <973176847@f38.n261.z1.binkp.net>

Steven D'Aprano wrote, on January 03, 2017 8:04 PM
>
> On Wednesday 04 January 2017 14:04, Deborah Swanson wrote:
>
> > Steve D'Aprano wrote, on January 03, 2017 4:56 PM
> [...]
> >> Python can't force the console to treat something as a clickable
> >> link, if the console has no capacity for clickable links. Nor can
> >> Python predict what format the console uses to recognise a link.
> >>
> >> The best you can do is to experiment with a couple of
> simple formats
> >> and see which, if any, your console understands:
> >>
> >> # HTML
> >> <a href="http://www.example.com">Example.</a>
> >>
> >> # URL in angle brackets
> >> Example <http://www.example.com>
> >>
> >> # URL alone
> >> http://www.example.com
> >>
> >> # I can't remember what these are called
> >> <url:http://www.example.com>
> >>
> >> # Markup
> >> [Example](http://www.example.com)
> >>
> >> # Rest
> >> `Example <http://www.example.com>`_
> [...]
>
> > I tried all of your examples in IDLE, and they all get
> syntax errors.
> > I'd expect the same from PyCharm, though I didn't try it.
>
> Syntax errors? How can you get syntax errors from *output* text?
>
> The above are just text, no different from:
>
>     Hello World!

I closed the IDLE window these were on, but the error arrow was pointing to 
punctuation in each case, a colon in one case, angle bracket in another. Sorta 
seems like IDLE is trying to do something with them and not taking them as 
simple plain text. But it's not making hyperlinks, so I'm not sure how much I 
care exactly what it's doing.

> Of course you have to put quotes around them to enter them in
> your source code.
> We don't expect this to work:
>
>     print(Hello World!)
>
>
> you have to use a string literal with quotes:
>
>     print('Hello World!')
>
>
> Same for all of the above.

I didn't try printing them before, but I just did. Got:

>>> print([Example](http://www.example.com)

SyntaxError: invalid syntax  (arrow pointing at the colon)

> py> print('<a href="http://www.example.com">Example.</a>')
> <a href="http://www.example.com">Example.</a>
>
>
> That's the Python interactive interpreter (with a custom
> prompt, I prefer "py>"
> rather than the default ">>>"). Or I can do this from the
> operating system's
> shell prompt:
>
> steve at runes:~$ python -c "print 'http://www.example.com'"
http://www.example.com


If I do this in GNOME Terminal 2.30.2, the URL http... is a clickable link. But
that's specific to the terminal. Other terminals may or may not recognise it.




--
Steven
"Ever since I learned about confirmation bias, I've been seeing it everywhere." 
- Jon Ronson

I need to get a new power supply in my Linux-capable machine, but for now I'm 
stuck with Winblows on a very old PC.

As I've mentioned in other posts on this thread, I'm now thinking that I need 
to write a class to do this, and find out how Firefox and url aware terminals 
in Linux do it. There must be a way.



From torriem at gmail.com  Tue Jan  3 03:51:36 2017
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 03 Jan 2017 20:51:36 +1200
Subject: Clickable hyperlinks
Message-ID: <231289290@f38.n261.z1.binkp.net>

On 01/03/2017 08:28 PM, Deborah Swanson wrote:
> I think you're making this too complicated. I meant a console in a GUI
> application.

Ahh. Well, a "console in a GUI application" is whatever you make it[1]. There's 
no single "GUI console" hence my confusion and the confusion expressed by the 
other poster.  I was under the impression you are talking about printing 
something to standard out with, for example, print().  Is this so, or are you 
using a GUI toolkit to construct your application.  What GUI toolkit are you 
using?  As I said, in Qt or GTK there are various ways to display hyperlinks.  
For example, Qt lets you place a hyperlink in a form, or inside of a text 
entry/display widget.

I still get the impression that you're working with standard out, using 
print(). If so, then no, there's not going to be a way to force the OS to make 
the output clickable, at least on Windows.

> Not true. Pycharm uses links in it's console output, they just aren't
> internet links. They link back to lines of code being referred to.

I think the problem here is the terminology with specific meaning in Windows 
and Linux.  I'm referring to either the Win32 console window (which is where 
cmd.exe runs), or a terminal emulator in Linux, which is where you can interact 
with the bash shell and run command-line programs.  When people normally run 
python apps that are not graphical, they normally do it from the Windows 
console (via cmd.exe) or in Linux from Bash running in a terminal emulator.  
Graphical apps do their own thing as far as displaying data and making windows 
with clickable links in them.

[1] PyCharm and IDLE make "console" windows that are really normal GUI windows 
and they direct the output from Python apps there. They may also choose to 
display clickable links for things like errors. But once the app is run outside 
of PyCharm, the output of the app would go to either a Windows console window, 
or a terminal in Linux.  If you wanted your app to make it's own window and 
display clickable links, you're back to looking at a GUI toolkit (which is what 
PyCharm and IDLE are built with) like Qt, GTK, Tk, wxWidgets, or something 
else.



From torriem at gmail.com  Tue Jan  3 04:05:18 2017
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 03 Jan 2017 21:05:18 +1200
Subject: Clickable hyperlinks
Message-ID: <1957399330@f38.n261.z1.binkp.net>

On 01/03/2017 08:46 PM, Deborah Swanson wrote:
> Actually it is, or at least it doesn't happen in all email readers.
> Mine, for instance, never breaks up threads.

Mine doesn't either, which illustrates the issue. This  message, for example 
appears under a long thread that started out life as "mentor training python 
Romania with certification" and then changed to "Cleaning up conditionals" and 
then changed to "Clickable hyperlinks." All in one thread. My client doesn't 
break them up because they all tie together via the message-id header.

And most of us would not like our client to break a thread just because the 
subject changes. Often in long conversations there are twists and turns in the 
discussion and sometimes side-paths are explored, and the subject often is 
changed to reflect this.  With a truly threaded email reader (one that shows a 
tree of messages, not just chronological order), this works out very well.  So 
if a discussion has a natural evolution into various other topics, it is often 
considered okay to just change the subject but continue the thread. Other 
times, it's better to start a new thread.  Where that line is is hard to say!

> I did say in the message you're replying to that I will try to remember
> to start new threads with brand new messages. (Even though I think
> pipermail's behavior is a bug, that's what many people read the list
> from.)

Sounds good.

I don't know of anyone that reads on the pipermail archive, except in response 
to web searches.  Most people use clients of some kind, NNTP or email.  And 
those that group messages according to message-id (most clients except for ones 
that try to be smart like Gmail web or Outlook) will show all the topics I 
mentioned before as one giant thread, which is by design (that's what 
message-id headers are for).



From python at deborahswanson.net  Tue Jan  3 04:18:26 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 01:18:26 -0800
Subject: Cleaning up conditionals
In-Reply-To: <CAPTjJmqC8oPpceQgpuMxMw64tfZ5aE91S1kjFnkeKax6RevgeA@mail.gmail.com>
Message-ID: <000f01d265a2$58022a90$27b23dae@sambora>

Chris Angelico wrote, on January 03, 2017 12:14 AM
> 
> On Tue, Jan 3, 2017 at 6:35 PM, Deborah Swanson 
> <python at deborahswanson.net> wrote:
> > I think I'm right that core python sequences can't be 
> indexed in any 
> > fashion by strings, because strings aren't iterable. I suppose it 
> > might be possible for strings to be iterable in some sort of ascii 
> > char code order, but that seems like it could get real whacky very 
> > fast, and not terribly useful.
> 
> It's not because they're not iterable, but because there's a 
> fundamental difference between a key-value pair (dict) and a 
> sequence. You can combine the two in several different ways, 
> none of which is the "one most obvious". Python's OrderedDict 
> retains the order of its keys; in contrast, a namedtuple is a 
> "record" type with a fixed set of keys that correspond to 
> positions in the record. In your case, I think a namedtuple 
> would be a good fit, but there's no general concept of 
> indexing a sequence with strings.
> 
> ChrisA

I hope I can get to namedtuples tomorrow, they do sound like an
excellent data structure for the purpose of using field titles as
subscripts. I'd never heard of them before, so I'm looking forward to
finding out what they are and how they work.

OrderedDict is the new development I'd read about, but I think the key
order is just the order keys were added to the dict. The nice thing
about that though is when you loop over a dict you will always get the
key/value pairs in the same order, where with the standard dict they
come out in arbitrary order. Very disconcerting if you're watching the
loop as it progresses over muiltiple executions. I imagine you could
sort an OrderedDict so the keys originally added randomly would be put
into some kind of good order.




From D.Strohl at F5.com  Tue Jan  3 04:34:56 2017
From: D.Strohl at F5.com (Dan Strohl)
Date: Tue, 03 Jan 2017 21:34:56 +1200
Subject: Clickable hyperlinks
Message-ID: <2213819274@f38.n261.z1.binkp.net>

The best bet (unless you know that you are outputting to a specific place, like 
html or excel) is to always include the "https://" or "http://" since most of 
the consoles / terminals that support clickable links are parsing them based on 
"seeing" the initial "http://".  If your output just looks like 
"mysite.com/coolpage.html", many systems will simply ignore them.

At one point I had made a class that you could pass the link to, and then you 
could request different output based on your needs... so basically something 
like:

>> url = url_class("mysite.com/coolpage.html")
>> print(url)
"http://mysite.com/coolpage.html")
>> print(url.plain)
"mysite.com/coolpage.html"
>> print(url.html('My Site"))
'<a href="http://mysite.com/coolpage.html">My Site</a>'

(or whatever... I think I actually just sub-classed url.parse or something)




-----Original Message-----
From: Python-list [mailto:python-list-bounces+d.strohl=f5.com at python.org] On
Behalf Of Devin Jeanpierre
Sent: Tuesday, January 03, 2017 12:57 PM To: python at deborahswanson.net
Cc: comp.lang.python <python-list at python.org>
Subject: Re: Clickable hyperlinks

Sadly, no. :(  Consoles (and stdout) are just text, not hypertext. The way to 
make an URL clickable is to use a terminal that makes URLs clickable, and print 
the URL:

print("%s: %s" % (description, url))

-- Devin

On Tue, Jan 3, 2017 at 11:46 AM, Deborah Swanson <python at deborahswanson.net> 
wrote:

> Excel has a formula:
>
> =HYPERLINK(url,description)
>
> that will put a clickable link into a cell.
>
> Does python have an equivalent function? Probably the most common use
> for it would be output to the console, similar to a print statement,
> but clickable.
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>
--
https://mail.python.org/mailman/listinfo/python-list



From m at funkyhat.org  Tue Jan  3 04:46:56 2017
From: m at funkyhat.org (Matt Wheeler)
Date: Tue, 03 Jan 2017 21:46:56 +1200
Subject: Screwing Up looping in Generator
Message-ID: <2039106472@f38.n261.z1.binkp.net>

On Tue, 3 Jan 2017 at 20:17 Deborah Swanson <python at deborahswanson.net> wrote:

> > What's the code for your generator? And I don't see where you
> > call 'next'.
>
> I think you're expecting
>
>         for file in rootobs
>
> to get the next yield for you from rootobs, but unless someone corrects
> me, I don't think you can expect a 'for' statement to do that. You need
> to have a 'next' statement inside your for loop to get the next yield
> from the generator.
>

Yes, you absolutely can expect a for statement to do that. It will accept any 
iterable as its `y`.

`for x in y: stuff(x)` is effectively syntactic sugar for:

iterator = iter(y)
while True:
    try:
        x = next(iterator)
    except(StopIteration):
        break
    stuff(x)

Manually calling `next()` inside a `while True:` is quite an unusual thing to 
do.

range() is not part of the for syntax at all, it's completely separate, it 
simply returns an iterator which the for loop can use, like any other.
--

--
Matt Wheeler
http://funkyh.at



From D.Strohl at F5.com  Tue Jan  3 04:47:58 2017
From: D.Strohl at F5.com (Dan Strohl)
Date: Tue, 03 Jan 2017 21:47:58 +1200
Subject: Clickable hyperlinks
Message-ID: <8394371@f38.n261.z1.binkp.net>

Keeping mind how this all works...

Python is providing the data, the console/terminal/app handles how that data is 
displayed.   There is no specification for text output to be hyperlinked (that
I know about at least), so while some apps may handle specific coding to tell 
them that "this text should be a hyperlink", most will either parse the text 
looking for hyper-linkable string, or more commonly, just output the text as 
text.

If you control the app that is displaying info to the user (such as using QT or 
another GUI tool), or generating html yourself, you can control if a text 
string is a hyperlink or not, and what to do with the hyperlink when clicked.

So, if you want clickable links, you would need to find a console/terminal that 
supported them.

Some references:
https://opensource.com/life/15/11/top-open-source-terminal-emulators  (see 
Gnome)
http://unix.stackexchange.com/questions/63417/is-there-a-terminal-app-that-allo
ws-filenames-to-be-clickable
http://superuser.com/questions/654116/configure-os-x-terminal-to-detect-urls-an
d-make-them-clickable
http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/url-launching.html


-----Original Message-----
From: Python-list [mailto:python-list-bounces+d.strohl=f5.com at python.org] On
Behalf Of Deborah Swanson
Sent: Tuesday, January 03, 2017 1:35 PM To: 'Devin Jeanpierre' 
<jeanpierreda at gmail.com>
Cc: 'comp.lang.python' <python-list at python.org>
Subject: RE: Re: Clickable hyperlinks

Devin Jeanpierre wrote, on January 03, 2017 12:57 PM

>Sadly, no. :(  Consoles (and stdout) are just text, not hypertext. The
way to
>make an URL clickable is to use a terminal that makes URLs clickable,
and
>print the URL:
>
>
>print("%s: %s" % (description, url))
>
>
>
>
>-- Devin

I'm sorry, I should have said a GUI console because I wouldn't expect a 
text-based console to produce clickable links. But it appears that a simple GUI 
console can't do it either. I have 3 GUI consoles and in all 3, when I ask:

print("%s: %s" % ("python.org list", 
"https://mail.python.org/mailman/listinfo/python-list"))

I get:
python.org list: https://mail.python.org/mailman/listinfo/python-list

(Outlook made the url clickable here, the python GUI consoles just output plain 
text.)

Pretty clearly the output is plain text because your format parameters are %s. 
Maybe the trick, if there is one, is in a format parameter for urls.



On Tue, Jan 3, 2017 at 11:46 AM, Deborah Swanson <python at deborahswanson.net> 
wrote:

Excel has a formula:

=HYPERLINK(url,description)

that will put a clickable link into a cell.

Does python have an equivalent function? Probably the most common use for it 
would be output to the console, similar to a print statement, but clickable.

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

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



From m at funkyhat.org  Tue Jan  3 04:49:22 2017
From: m at funkyhat.org (Matt Wheeler)
Date: Tue, 03 Jan 2017 21:49:22 +1200
Subject: Screwing Up looping in Generator
Message-ID: <3875811198@f38.n261.z1.binkp.net>

On Tue, 3 Jan 2017 at 21:46 Matt Wheeler <m at funkyhat.org> wrote:

> range() is not part of the for syntax at all, it's completely separate, it
> simply returns an iterator which the for loop can use, like any other.
>

*iterable
--

--
Matt Wheeler
http://funkyh.at



From rustompmody at gmail.com  Tue Jan  3 04:57:08 2017
From: rustompmody at gmail.com (Rustom Mody)
Date: Tue, 03 Jan 2017 21:57:08 +1200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
References: <1794692783@f38.n261.z1.binkp.net>
Message-ID: <498925202@f38.n261.z1.binkp.net>

On Wednesday, January 4, 2017 at 5:42:34 AM UTC+5:30, Dietmar Schwertberger 
wrote:
> On 02.01.2017 12:38, Antonio Caminero Garcia wrote:
> > The thing with the from-the-scratch full featured IDEs (Eclipse, IntelliJ,
Pycharm) is that they look like a space craft dashboard and that unwarranted 
resources consumption and the unnecessary icons.
> You did not try Wing IDE? It looks less like a spacecraft. Maybe you
> like it.
> Maybe the difference is that Wing is from Python people while the ones
> you listed are from Java people.
> For something completely different (microcontroller programming in C) I
> just switched to a Eclipse derived IDE and I don't like it too much as
> the tool does not focus on the problem scope.
>
>  From your posts I'm not sure whether you want an editor or an IDE,
> where for me the main difference is the debugger and code completion.
> I would not want to miss the IDE features any more, even though in my
> first 15 years of Python I thought that a debugger is optional with
> Python ...
>
> Regards,
>
> Dietmar

Im surprised no one's talked of idle (or Ive missed it?)



From rosuav at gmail.com  Tue Jan  3 04:58:08 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 3 Jan 2017 20:58:08 +1100
Subject: Cleaning up conditionals
In-Reply-To: <000f01d265a2$58022a90$27b23dae@sambora>
References: <CAPTjJmqC8oPpceQgpuMxMw64tfZ5aE91S1kjFnkeKax6RevgeA@mail.gmail.com>
 <000f01d265a2$58022a90$27b23dae@sambora>
Message-ID: <CAPTjJmoD9hWsnK1M7jjrZ9XbCyy2UhH=nqXn3c4BWfegaKRipw@mail.gmail.com>

On Tue, Jan 3, 2017 at 8:18 PM, Deborah Swanson
<python at deborahswanson.net> wrote:
> OrderedDict is the new development I'd read about, but I think the key
> order is just the order keys were added to the dict. The nice thing
> about that though is when you loop over a dict you will always get the
> key/value pairs in the same order, where with the standard dict they
> come out in arbitrary order. Very disconcerting if you're watching the
> loop as it progresses over muiltiple executions. I imagine you could
> sort an OrderedDict so the keys originally added randomly would be put
> into some kind of good order.

If you want a "SortedDict", you can get that fairly easily just by
iterating over sorted(d) rather than simply d. You can also subclass
the dictionary and change how it iterates, if you like.

ChrisA


From uri at speedy.net  Tue Jan  3 05:07:38 2017
From: uri at speedy.net (Uri Even-Chen)
Date: Tue, 03 Jan 2017 22:07:38 +1200
Subject: pip install -r requirements.txt fails with Python 3.6 on Windows
Message-ID: <356961045@f38.n261.z1.binkp.net>

Thank you, I'll consider to update our requirements to latest versions of all 
packages. Last time I checked in 22th December 2016 and all our requirements 
were the latest versions. In the meantime we can keep using Python 3.5. By the 
way, Travis CI tests passed with the same requirements and Python 3.6 (and 3.5 
and 3.4). How did it install the requirements there? Does it depend on the 
operating system?

I see now that Python 3.6.0 was released on 2016-12-23.

By the way we use Ubuntu 16.04 in production with Python 3.5.2, so it's not 
that important to support Python 3.6 right now. What are the reasons to upgrade 
Python to 3.6?

Thanks,
Uri.


*Uri Even-Chen*
[image: photo] Phone: +972-54-3995700 Email: uri at speedy.net
Website: http://www.speedysoftware.com/uri/en/
<http://www.facebook.com/urievenchen>  <http://plus.google.com/+urievenchen>
  <http://www.linkedin.com/in/urievenchen>  <http://github.com/urievenchen>
<http://twitter.com/urievenchen>



From wlfraed at ix.netcom.com  Tue Jan  3 05:15:02 2017
From: wlfraed at ix.netcom.com (Dennis Lee Bieber)
Date: Tue, 03 Jan 2017 22:15:02 +1200
Subject: Hey, I'm new to python so don't judge.
Message-ID: <1104592092@f38.n261.z1.binkp.net>

On Tue, 3 Jan 2017 16:27:33 -0800 (PST), Callum Robinson
<cr2001 at hotmail.co.nz> declaimed the following:

>On Wednesday, January 4, 2017 at 1:17:11 PM UTC+13, Chris Angelico wrote:
>> On Wed, Jan 4, 2017 at 11:03 AM, Erik <python at lucidity.plus.com> wrote:
>> > I doubt it's getting that far (I can see at least one syntax error in the
>> > code pasted).
>>
>> True true. In any case, the point is to copy and paste the error
>> message. Callum, please, copy and paste it.
>>
>> ChrisA
>
>I'm sorry if I'm doing something wrong but all that is happening is when i try
to run it a popup says Invalid syntax

        And that statement tells us you are trying to run from within some
IDE/editor which is trapping Python exceptions and producing a dialog box
for them.

        Instead, save your script (if you haven't yet) as a file (whatever.py).

        Open a command line interpreter/shell.

        Navigate (cd ...) to where you saved the file

        Type "python whatever.py"

        Copy and paste the results of the CLI/Shell window.
--
        Wulfraed                 Dennis Lee Bieber         AF6VN
    wlfraed at ix.netcom.com    HTTP://wlfraed.home.netcom.com/



From orgnut at yahoo.com  Tue Jan  3 05:27:10 2017
From: orgnut at yahoo.com (Larry Hudson)
Date: Tue, 03 Jan 2017 22:27:10 +1200
Subject: Hey, I'm new to python so don't judge.
References: <306187502@f38.n261.z1.binkp.net>
Message-ID: <3188129962@f38.n261.z1.binkp.net>

On 01/03/2017 04:27 PM, Callum Robinson wrote:
> On Wednesday, January 4, 2017 at 1:17:11 PM UTC+13, Chris Angelico wrote:
>> On Wed, Jan 4, 2017 at 11:03 AM, Erik <python at lucidity.plus.com> wrote:
>>> I doubt it's getting that far (I can see at least one syntax error in the
>>> code pasted).
>>
>> True true. In any case, the point is to copy and paste the error
>> message. Callum, please, copy and paste it.
>>
>> ChrisA
>
> I'm sorry if I'm doing something wrong but all that is happening is when i
try to run it a popup says Invalid syntax
>

Exactly HOW are you running this?

If you are getting a popup, I suspect you are using an on-line version in a 
browser.  To get the
proper Python error messages (called Tracebacks) you MUST run the program in a 
terminal on your
own computer.  These tracebacks are VERY informative (once you get used to 
them).   :-)
And these tracebacks are what WE need to see to help you.

You DO have Python installed, don't you?

--
      -=- Larry -=-



From wlfraed at ix.netcom.com  Tue Jan  3 05:31:22 2017
From: wlfraed at ix.netcom.com (Dennis Lee Bieber)
Date: Tue, 03 Jan 2017 22:31:22 +1200
Subject: Hey, I'm new to python so don't judge.
Message-ID: <1440717869@f38.n261.z1.binkp.net>

On Tue, 3 Jan 2017 18:47:43 -0800 (PST), Callum Robinson
<cr2001 at hotmail.co.nz> declaimed the following:


>
>hello.
>I have thought of a number between 1 and 100.
>Can you guess it?
>5
>Low
>Sorry , you are too high. Try again.
>
>Does this mean the number i entered is to low but the code is still stating it
is to high?

        Is that a cut&paste from some console window, or are you just retyping
what you think it did?

        Nothing in your previous code produces the word "Low" -- it will
produce "low" (notice the case).

        And where in your code do you test for that return word?


        To simplify things -- don't return words from your function... change
it to return +1 for high, -1 for low, and 0 for "win".

        Then figure out how to modify the main loop to use those integers...

--
        Wulfraed                 Dennis Lee Bieber         AF6VN
    wlfraed at ix.netcom.com    HTTP://wlfraed.home.netcom.com/



From tonycamgar at gmail.com  Tue Jan  3 05:54:10 2017
From: tonycamgar at gmail.com (Antonio Caminero Garcia)
Date: Tue, 03 Jan 2017 22:54:10 +1200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
References: <1794692783@f38.n261.z1.binkp.net>
Message-ID: <694630219@f38.n261.z1.binkp.net>

On Tuesday, January 3, 2017 at 4:12:34 PM UTC-8, Dietmar Schwertberger wrote:
> On 02.01.2017 12:38, Antonio Caminero Garcia wrote:
> You did not try Wing IDE? It looks less like a spacecraft. Maybe you
> like it.
> Maybe the difference is that Wing is from Python people while the ones
> you listed are from Java people.

That sounds interesting. By the look of it I think I am going to give it a try.

> For something completely different (microcontroller programming in C) I
> just switched to a Eclipse derived IDE and I don't like it too much as
> the tool does not focus on the problem scope.

If it happens to be Arduino I normally use a sublime plugin called Stino 
https://github.com/Robot-Will/Stino
(1337 people starred that cool number :D)

>  From your posts I'm not sure whether you want an editor or an IDE,
> where for me the main difference is the debugger and code completion.

I want editor with those IDE capabilities and git integration, with optionally 
cool stuff as for example remote debugging.

> I would not want to miss the IDE features any more, even though in my
> first 15 years of Python I thought that a debugger is optional with
> Python ...

Unfortunately most of the time I am still using print and input functions. I 
know that sucks, I did not use the pdb module, I guess that IDE debuggers 
leverage such module.

> Regards,
>
> Dietmar

Thank you so much for your answer.



From grant.b.edwards at gmail.com  Tue Jan  3 06:13:10 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Tue, 03 Jan 2017 23:13:10 +1200
Subject: Clickable hyperlinks
Message-ID: <2633620841@f38.n261.z1.binkp.net>

On 2017-01-03, Deborah Swanson <python at deborahswanson.net> wrote:

> I'm sorry, I should have said a GUI console because I wouldn't expect a
> text-based console to produce clickable links.

What's a "GUI console"?

--
Grant Edwards               grant.b.edwards        Yow! I want you to MEMORIZE
                                  at               the collected poems of
                              gmail.com            EDNA ST VINCENT MILLAY
                                                   ... BACKWARDS!!



From robertvstepp at gmail.com  Tue Jan  3 06:18:16 2017
From: robertvstepp at gmail.com (boB Stepp)
Date: Tue, 03 Jan 2017 23:18:16 +1200
Subject: Clickable hyperlinks
Message-ID: <533172374@f38.n261.z1.binkp.net>

On Tue, Jan 3, 2017 at 10:46 PM, Deborah Swanson
<python at deborahswanson.net> wrote:
>

>
> I didn't try printing them before, but I just did. Got:
>
> >>> print([Example](http://www.example.com)
>
> SyntaxError: invalid syntax  (arrow pointing at the colon)

As Steve had said, you need to put everything inside quotes.  Also, you are 
missing a matching paren.  Thus:

py3: print("[Example](http://www.example.com)") 
[Example](http://www.example.com)

As to whether anything will be "clickable" or not, what has already been said 
about different types of terminals applies.

--
boB



From maillist at schwertberger.de  Tue Jan  3 06:20:36 2017
From: maillist at schwertberger.de (Dietmar Schwertberger)
Date: Tue, 03 Jan 2017 23:20:36 +1200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
Message-ID: <1794692783@f38.n261.z1.binkp.net>

On 02.01.2017 12:38, Antonio Caminero Garcia wrote:
> The thing with the from-the-scratch full featured IDEs (Eclipse, IntelliJ,
Pycharm) is that they look like a space craft dashboard and that unwarranted 
resources consumption and the unnecessary icons. You did not try Wing IDE? It 
looks less like a spacecraft. Maybe you like it.
Maybe the difference is that Wing is from Python people while the ones you 
listed are from Java people.
For something completely different (microcontroller programming in C) I just 
switched to a Eclipse derived IDE and I don't like it too much as the tool does 
not focus on the problem scope.

 From your posts I'm not sure whether you want an editor or an IDE,
where for me the main difference is the debugger and code completion. I would 
not want to miss the IDE features any more, even though in my first 15 years of 
Python I thought that a debugger is optional with Python ...

Regards,

Dietmar



From python at lucidity.plus.com  Tue Jan  3 06:30:26 2017
From: python at lucidity.plus.com (Erik)
Date: Tue, 03 Jan 2017 23:30:26 +1200
Subject: Clickable hyperlinks
Message-ID: <1719453483@f38.n261.z1.binkp.net>

Hi.

On 03/01/17 19:46, Deborah Swanson wrote:
> Excel has a formula:

When you start a new topic on the list, could you please write a new message 
rather than replying to an existing message and changing the title/subject?

For those reading the list in a threaded email client, this message is shown as 
a continuation of your "Cleaning up conditionals" thread, and that whole thread 
in turn shows up as a continuation of the "mentor training python Romania with 
certification" discussion (which you had presumably "reply"ed to originally) 
...

Thanks. E.



From python at lucidity.plus.com  Tue Jan  3 06:44:50 2017
From: python at lucidity.plus.com (Erik)
Date: Tue, 03 Jan 2017 23:44:50 +1200
Subject: Screwing Up looping in Generator
Message-ID: <1135185308@f38.n261.z1.binkp.net>

Hi,

On 03/01/17 22:14, Deborah Swanson wrote:
> ...you have to create the generator object first and use it to call the
> next function. And I really don't think you can use a generator as your
> range in a for loop. So I'd use a 'while True', and break out of the
> loop when you hit the StopIteration exception:
>
> files = rootobs()
>
> while True:
>   try:
>     file = files.next()
>   except StopIteration:
>     break
>
>     base = os.path.basename(file.name)
>        .
>        .
>        .
>       (etc)

What you have done there is taken an understanding of the underlying machinery 
that allows the 'for' loop to be syntactic sugar over any iterable and spelled 
it out, instead of just using 'for'! Without all that, your example is:

for file in rootobs():
   base = os.path.basename(file.name)
   .
   .
   .
   (etc)

[In fact, the machinery would also cope with the return value from rootobs() 
being an iterable but not an iterator by using "files = iter(rootobjs)"].



You seem to be reading up on how the stuff works under the covers (i.e., from 
the point of view of an implementer of a class or library) and then suggesting 
that that's what the *caller* of that class or library needs to do. They don't 
- for a caller, 'for x in seq:' is all they need to know - the mechanics are 
handled by the interpreter coupled with the dunder methods that the class may 
implement.


E.



From python at lucidity.plus.com  Tue Jan  3 06:53:16 2017
From: python at lucidity.plus.com (Erik)
Date: Tue, 03 Jan 2017 23:53:16 +1200
Subject: Screwing Up looping in Generator
Message-ID: <2712032730@f38.n261.z1.binkp.net>

On 03/01/17 23:05, Deborah Swanson wrote:
> And yes, we usually used for loops for generators, unless you don't know
> when the generator will be exhausted. As in this case, where the number
> of files the generator can provide is unknown. Then we used the while
> True, break on StopIteration method.

Out of interest, *why* was it deemed necessary to do something different if you 
don't know how many items the generator will generate? Was any rationale given 
for that?

for x in foo:
   bar(x)

... where foo is any iterable (something that has a __iter__ method defined - 
including generators) will just bind each value in turn to 'x' and will exit 
when the StopIteration exception is raised under the covers by the iterator 
that is iterating over the iterable.

Some generators are infinite (and their iterator will never raise a 
StopIteration exception).

E.



From python at lucidity.plus.com  Tue Jan  3 07:03:02 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 04 Jan 2017 00:03:02 +1200
Subject: Hey, I'm new to python so don't judge.
Message-ID: <731385204@f38.n261.z1.binkp.net>

On 03/01/17 23:56, Chris Angelico wrote:
> On Wed, Jan 4, 2017 at 10:49 AM,  <cr2001 at hotmail.co.nz> wrote:
>> #think of a number
>> computer_number = number.randint(1,100)
>
> What's wrong is that you aren't showing us the exception you get on
> this line. *Copy and paste* that exception - the whole thing. It's
> very helpful.

I doubt it's getting that far (I can see at least one syntax error in the code 
pasted).

cr2001: I echo Chris's sentiment though - what is the error you are seeing (in 
it's entirety)?

E.



From wlfraed at ix.netcom.com  Tue Jan  3 07:17:52 2017
From: wlfraed at ix.netcom.com (Dennis Lee Bieber)
Date: Wed, 04 Jan 2017 00:17:52 +1200
Subject: Clickable hyperlinks
Message-ID: <40458775@f38.n261.z1.binkp.net>

On Tue, 3 Jan 2017 20:46:31 -0800, "Deborah Swanson"
<python at deborahswanson.net> declaimed the following:

>
>I didn't try printing them before, but I just did. Got:
>
>>>> print([Example](http://www.example.com)
>
>SyntaxError: invalid syntax  (arrow pointing at the colon)
>

        As I mentioned to someone else earlier...

        Count your parentheses... You need a ) for each (

AND you need " (or ') around the strings.

        As you entered it, you have invoked a print operation, passing it:

A list containing a reference to a (undefined) variable "Example", and then you 
attempt call that list as a function passing it some unrecognized keyword 
"http" with a colon that Python normally uses indicate the start of a code 
block; said block being "//www.example.com".

Try

print("[Example](http://www.example.com)")

--
        Wulfraed                 Dennis Lee Bieber         AF6VN
    wlfraed at ix.netcom.com    HTTP://wlfraed.home.netcom.com/



From python at lucidity.plus.com  Tue Jan  3 07:22:16 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 04 Jan 2017 00:22:16 +1200
Subject: How Best to Coerce Python Objects to Integers?
Message-ID: <1909730512@f38.n261.z1.binkp.net>

On 03/01/17 22:47, Chris Angelico wrote:
> On Wed, Jan 4, 2017 at 9:42 AM, Ethan Furman <ethan at stoneleaf.us> wrote:
>> Aside from calling "except Exception" a "naked except"
>
> If you read the comments, you'll see that he originally had an actual
> bare except clause, but then improved the code somewhat in response to
> a recommendation that SystemExit etc not be caught.

But, as stated at the top of the article, his brief was: "The strings come from 
a file that a human has typed in, so even though most of the values are good, a 
few will have errors ('25C') that int() will reject.".

What he *should* have done is just validated his input strings before 
presenting the string to int() - i.e., process the input with knowledge that is 
specific to the problem domain before calling the general-purpose function.

He mentions temperature sensors, so perhaps stripping a trailing 'c' or
'C' is a reasonable thing to do (or even, if there's a trailing 'f' or
'F', performing a numerical conversion after the value is known).

Instead, he tried to patch around int() rejecting the strings. And then decided 
that he'd patch around int() rejecting things that weren't even strings even 
though that's not what the function has (apparently) been specified to receive.

The "bulletproof" result will convert "25C" to None even though 25 is probably 
a reasonable result for that string in his domain problem domain.

E.



From python at lucidity.plus.com  Tue Jan  3 07:26:12 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 04 Jan 2017 00:26:12 +1200
Subject: Hey, I'm new to python so don't judge.
Message-ID: <1486132539@f38.n261.z1.binkp.net>

Hi Callum,

On 04/01/17 00:02, Callum Robinson wrote:
 > When i check the code it comes up with invalid syntax and my writing
line gets re directed here
 >
 > def is_same(target, number:
 >         if target == number:
 >             result="win"
 >         elif target > number:
 >             result="low"
 >         else:
 >             result="high"
 >         return result

OK, good. That implies it's something wrong with the function definition 
('def'). Look at that very carefully :)   (*)

E.

(*) My emoticon may give you a hint ...



From python at lucidity.plus.com  Tue Jan  3 07:45:08 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 04 Jan 2017 00:45:08 +1200
Subject: Hey, I'm new to python so don't judge.
Message-ID: <2189830552@f38.n261.z1.binkp.net>

Hi Callum,

On 04/01/17 00:30, Callum Robinson wrote:
> I feel like im missing something so blatantly obvious.

That's because you are ;). I don't want to come across as patronising, but I 
want you to see it for yourself, so, here's a function definition similar to 
yours that doesn't have the same syntax error that yours does:

def foo(spam, ham):
     if spam == ham:
         return "same"
     return "different"

See the difference?

E.



From python at lucidity.plus.com  Tue Jan  3 07:47:54 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 04 Jan 2017 00:47:54 +1200
Subject: Hey, I'm new to python so don't judge.
Message-ID: <3434470369@f38.n261.z1.binkp.net>

On 04/01/17 00:32, Callum Robinson wrote:
> I forgot a bloody bracket xD

Cool, you got it ;) It's the sort of thing your brain will see instantly once 
you've done it a few times :D

> and now theirs a new error ill try to figure this out on my own.

You need to look back to Chris's original reply, I suspect (his reply was 
pointing out a runtime issue that will happen once the syntax issue is 
resolved) ...

E.



From smitty1e at gmail.com  Tue Jan  3 07:55:06 2017
From: smitty1e at gmail.com (smitty1e)
Date: Tue, 3 Jan 2017 04:55:06 -0800 (PST)
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
Message-ID: <a9031171-eaf8-4d62-b6e7-243d52cb37e3@googlegroups.com>

On Monday, January 2, 2017 at 6:39:03 AM UTC-5, Antonio Caminero Garcia wrote:
> Hello, I am having a hard time deciding what IDE or IDE-like code editor should I use. This can be overwhelming.
> 
> So far, I have used Vim, Sublime, Atom, Eclipse with PyDev, Pycharm, IntelliJ with Python plugin. 
> 
> The thing with the from-the-scratch full featured IDEs (Eclipse, IntelliJ, Pycharm) is that they look like a space craft dashboard and that unwarranted resources consumption and the unnecessary icons. I want my IDE to be minimalistic but powerful. My screen should be mostly ?made of code? as usually happens in Vim, Sublime or Atom. However, Pycharm is really cool and python oriented.
> 
> The problem with Vim is the learning curve, so I know the very basic stuff, but obviously not enough for coding and I do not have time to learn it, it is a pity because there are awesome plugins that turns Vim into a lightweight powerful IDE-like. So now it is not an option but I will reconsider it in the future, learning little by little. Also, I am not very fan GUI guy if the task can be accomplished through the terminal. However, I don?t understand why people underrate GUIs, that said I normally use shortcuts for the most frequent tasks and when I have to do something that is not that frequent then I do it with the mouse, for the latter case in vim you would need to look for that specific command every time. 
> 
> Sublime is my current and preferred code editor. I installed Anaconda, Git integration and a couple of additional plugins that make sublime very powerful. Also, what I like about sublime compared to the full featured IDEs, besides the minimalism, is how you can perform code navigation back and forth so fast, I mean this is something that you can also do with the others but for some subjective reason I specifically love how sublime does it. The code completion in sublime I do not find it very intelligence, the SublimeCodeIntel is better than the one that Anaconda uses but the completions are not as verbose as in the IDEs.
> 
> Now, I am thinking about giving a try to Visual Studio Code Edition (take a look, it sounds good https://marketplace.visualstudio.com/items?itemName=donjayamanne.python). I need an editor for professional software development. What would you recommend to me?

I am told that means other than Emacs exist to edit code and interact with systems, but I don't worry about them.

Happy New Year,
Chris


From python at deborahswanson.net  Tue Jan  3 08:00:54 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 04 Jan 2017 01:00:54 +1200
Subject: Clickable hyperlinks
Message-ID: <759429036@f38.n261.z1.binkp.net>

Michael Torrie wrote, on January 03, 2017 8:05 PM
>
> On 01/03/2017 08:46 PM, Deborah Swanson wrote:
> > Actually it is, or at least it doesn't happen in all email readers.
> > Mine, for instance, never breaks up threads.
>
> Mine doesn't either, which illustrates the issue. This
> message, for example appears under a long thread that started
> out life as "mentor training python Romania with
> certification" and then changed to "Cleaning up conditionals"
> and then changed to "Clickable hyperlinks." All in one
> thread. My client doesn't break them up because they all tie
> together via the message-id header.
>
> And most of us would not like our client to break a thread
> just because the subject changes. Often in long conversations
> there are twists and turns in the discussion and sometimes
> side-paths are explored, and the subject often is changed to
> reflect this.  With a truly threaded email reader (one that
> shows a tree of messages, not just chronological order), this
> works out very well.  So if a discussion has a natural
> evolution into various other topics, it is often considered
> okay to just change the subject but continue the thread.
> Other times, it's better to start a new thread.  Where that
> line is is hard to say!
>
> > I did say in the message you're replying to that I will try to
> > remember to start new threads with brand new messages.
> (Even though I
> > think pipermail's behavior is a bug, that's what many
> people read the
> > list
> > from.)
>
> Sounds good.
>
> I don't know of anyone that reads on the pipermail archive,
> except in response to web searches.  Most people use clients
> of some kind, NNTP or email.  And those that group messages
> according to message-id (most clients except for ones that
> try to be smart like Gmail web or Outlook) will show all the
> topics I mentioned before as one giant thread, which is by
> design (that's what message-id headers are for).

I suppose. Times change of course, which always suits some and not others. 
Personally, I think putting messages that have different titles all in one 
thread is a bad design, but as I've said a couple of times now I intend to 
comply with the new rules. But compliance doesn't imply agreement. I prefer the 
old system, which ordered threads by titles, but there's obviously no pleasing 
everyone on this issue.



From uri at speedy.net  Tue Jan  3 08:19:17 2017
From: uri at speedy.net (Uri Even-Chen)
Date: Tue, 3 Jan 2017 15:19:17 +0200
Subject: pip install -r requirements.txt fails with Python 3.6 on Windows 10
Message-ID: <CAMQ2MsFS-YHajpia_Q_s6dses2MAj7zeMir69CcPQ9R6Tr1MvQ@mail.gmail.com>

(.venv) C:\Uri\Speedy Net\Git\speedy-net [public]>pip install -r
requirements.txt
Requirement already satisfied: Django==1.10.4 in c:\uri\speedy
net\git\speedy-net [public]\.venv\lib\site-packages (from -r
requirements.txt (line 2))
Requirement already satisfied: django-crispy-forms==1.6.1 in c:\uri\speedy
net\git\speedy-net [public]\.venv\lib\site-packages (from -r
requirements.txt (line 3))
Requirement already satisfied: django-debug-toolbar==1.6 in c:\uri\speedy
net\git\speedy-net [public]\.venv\lib\site-packages (from -r
requirements.txt (line 4))
Requirement already satisfied: django-environ==0.4.1 in c:\uri\speedy
net\git\speedy-net [public]\.venv\lib\site-packages (from -r
requirements.txt (line 5))
Requirement already satisfied: django-friendship==1.5.0 in c:\uri\speedy
net\git\speedy-net [public]\.venv\lib\site-packages (from -r
requirements.txt (line 6))
Requirement already satisfied: django-modeltranslation==0.12 in
c:\uri\speedy net\git\speedy-net [public]\.venv\lib\site-packages (from -r
requirements.txt (line 7))
Requirement already satisfied: factory-boy==2.8.1 in c:\uri\speedy
net\git\speedy-net [public]\.venv\lib\site-packages (from -r
requirements.txt (line 8))
Requirement already satisfied: Faker==0.7.7 in c:\uri\speedy
net\git\speedy-net [public]\.venv\lib\site-packages (from -r
requirements.txt (line 9))
Collecting Pillow==3.4.2 (from -r requirements.txt (line 10))
  Using cached Pillow-3.4.2.tar.gz
Requirement already satisfied: python-dateutil==2.6.0 in c:\uri\speedy
net\git\speedy-net [public]\.venv\lib\site-packages (from -r
requirements.txt (line 11))
Collecting rules==1.2 (from -r requirements.txt (line 12))
  Using cached rules-1.2.tar.gz
Requirement already satisfied: six==1.10.0 in c:\uri\speedy
net\git\speedy-net [public]\.venv\lib\site-packages (from -r
requirements.txt (line 13))
Collecting sorl-thumbnail==12.4a1 (from -r requirements.txt (line 14))
  Using cached sorl_thumbnail-12.4a1-py2.py3-none-any.whl
Requirement already satisfied: sqlparse==0.2.2 in c:\uri\speedy
net\git\speedy-net [public]\.venv\lib\site-packages (from -r
requirements.txt (line 15))
Installing collected packages: Pillow, rules, sorl-thumbnail
  Running setup.py install for Pillow ... error
    Complete output from command "c:\uri\speedy net\git\speedy-net
[public]\.venv\scripts\python.exe" -u -c "import setuptools,
tokenize;__file__='C:\\Users\\Uri\\AppData\\Local\\Temp\\pip-build-3dj7ngjs\\Pillow\\setup.py';f=getattr(tokenize,
'open', open)(__file__);code=f.read().replace('\r\n',
'\n');f.close();exec(compile(code, __file__, 'exec'))" install --record
C:\Users\Uri\AppData\Local\Temp\pip-1464cmd1-record\install-record.txt
--single-version-externally-managed --compile --install-headers
"c:\uri\speedy net\git\speedy-net
[public]\.venv\include\site\python3.6\Pillow":
    Single threaded build for windows
    running install
    running build
    running build_py
    creating build
    creating build\lib.win32-3.6
    creating build\lib.win32-3.6\PIL
    copying PIL\BdfFontFile.py -> build\lib.win32-3.6\PIL
    copying PIL\BmpImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\BufrStubImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\ContainerIO.py -> build\lib.win32-3.6\PIL
    copying PIL\CurImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\DcxImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\DdsImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\EpsImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\ExifTags.py -> build\lib.win32-3.6\PIL
    copying PIL\features.py -> build\lib.win32-3.6\PIL
    copying PIL\FitsStubImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\FliImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\FontFile.py -> build\lib.win32-3.6\PIL
    copying PIL\FpxImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\FtexImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\GbrImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\GdImageFile.py -> build\lib.win32-3.6\PIL
    copying PIL\GifImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\GimpGradientFile.py -> build\lib.win32-3.6\PIL
    copying PIL\GimpPaletteFile.py -> build\lib.win32-3.6\PIL
    copying PIL\GribStubImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\Hdf5StubImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\IcnsImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\IcoImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\Image.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageChops.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageCms.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageColor.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageDraw.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageDraw2.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageEnhance.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageFile.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageFilter.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageFont.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageGrab.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageMath.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageMode.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageMorph.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageOps.py -> build\lib.win32-3.6\PIL
    copying PIL\ImagePalette.py -> build\lib.win32-3.6\PIL
    copying PIL\ImagePath.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageQt.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageSequence.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageShow.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageStat.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageTk.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageTransform.py -> build\lib.win32-3.6\PIL
    copying PIL\ImageWin.py -> build\lib.win32-3.6\PIL
    copying PIL\ImImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\ImtImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\IptcImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\Jpeg2KImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\JpegImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\JpegPresets.py -> build\lib.win32-3.6\PIL
    copying PIL\McIdasImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\MicImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\MpegImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\MpoImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\MspImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\OleFileIO.py -> build\lib.win32-3.6\PIL
    copying PIL\PaletteFile.py -> build\lib.win32-3.6\PIL
    copying PIL\PalmImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\PcdImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\PcfFontFile.py -> build\lib.win32-3.6\PIL
    copying PIL\PcxImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\PdfImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\PixarImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\PngImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\PpmImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\PsdImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\PSDraw.py -> build\lib.win32-3.6\PIL
    copying PIL\PyAccess.py -> build\lib.win32-3.6\PIL
    copying PIL\SgiImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\SpiderImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\SunImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\TarIO.py -> build\lib.win32-3.6\PIL
    copying PIL\TgaImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\TiffImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\TiffTags.py -> build\lib.win32-3.6\PIL
    copying PIL\WalImageFile.py -> build\lib.win32-3.6\PIL
    copying PIL\WebPImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\WmfImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\XbmImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\XpmImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\XVThumbImagePlugin.py -> build\lib.win32-3.6\PIL
    copying PIL\_binary.py -> build\lib.win32-3.6\PIL
    copying PIL\_tkinter_finder.py -> build\lib.win32-3.6\PIL
    copying PIL\_util.py -> build\lib.win32-3.6\PIL
    copying PIL\__init__.py -> build\lib.win32-3.6\PIL
    running egg_info
    writing Pillow.egg-info\PKG-INFO
    writing dependency_links to Pillow.egg-info\dependency_links.txt
    writing top-level names to Pillow.egg-info\top_level.txt
    warning: manifest_maker: standard file '-c' not found

    reading manifest file 'Pillow.egg-info\SOURCES.txt'
    reading manifest template 'MANIFEST.in'
    warning: no files found matching '*.sh'
    no previously-included directories found matching 'docs\_static'
    warning: no previously-included files found matching '.coveragerc'
    warning: no previously-included files found matching '.editorconfig'
    warning: no previously-included files found matching '.landscape.yaml'
    warning: no previously-included files found matching 'appveyor.yml'
    warning: no previously-included files found matching 'build_children.sh'
    warning: no previously-included files found matching 'tox.ini'
    warning: no previously-included files matching '.git*' found anywhere
in distribution
    warning: no previously-included files matching '*.pyc' found anywhere
in distribution
    warning: no previously-included files matching '*.so' found anywhere in
distribution
    writing manifest file 'Pillow.egg-info\SOURCES.txt'
    copying PIL\OleFileIO-README.md -> build\lib.win32-3.6\PIL
    running build_ext
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File
"C:\Users\Uri\AppData\Local\Temp\pip-build-3dj7ngjs\Pillow\setup.py", line
753, in <module>
        zip_safe=not debug_build(), )
      File
"C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\core.py",
line 148, in setup
        dist.run_commands()
      File
"C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\dist.py",
line 955, in run_commands
        self.run_command(cmd)
      File
"C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\dist.py",
line 974, in run_command
        cmd_obj.run()
      File "c:\uri\speedy net\git\speedy-net
[public]\.venv\lib\site-packages\setuptools\command\install.py", line 61,
in run
        return orig.install.run(self)
      File
"C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\command\install.py",
line 545, in run
        self.run_command('build')
      File
"C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\cmd.py",
line 313, in run_command
        self.distribution.run_command(command)
      File
"C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\dist.py",
line 974, in run_command
        cmd_obj.run()
      File
"C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\command\build.py",
line 135, in run
        self.run_command(cmd_name)
      File
"C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\cmd.py",
line 313, in run_command
        self.distribution.run_command(command)
      File
"C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\dist.py",
line 974, in run_command
        cmd_obj.run()
      File
"C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\command\build_ext.py",
line 339, in run
        self.build_extensions()
      File
"C:\Users\Uri\AppData\Local\Temp\pip-build-3dj7ngjs\Pillow\setup.py", line
521, in build_extensions
        ' using --disable-%s, aborting' % (f, f))
    ValueError: zlib is required unless explicitly disabled using
--disable-zlib, aborting

    ----------------------------------------
Command ""c:\uri\speedy net\git\speedy-net
[public]\.venv\scripts\python.exe" -u -c "import setuptools,
tokenize;__file__='C:\\Users\\Uri\\AppData\\Local\\Temp\\pip-build-3dj7ngjs\\Pillow\\setup.py';f=getattr(tokenize,
'open', open)(__file__);code=f.read().replace('\r\n',
'\n');f.close();exec(compile(code, __file__, 'exec'))" install --record
C:\Users\Uri\AppData\Local\Temp\pip-1464cmd1-record\install-record.txt
--single-version-externally-managed --compile --install-headers
"c:\uri\speedy net\git\speedy-net
[public]\.venv\include\site\python3.6\Pillow"" failed with error code 1 in
C:\Users\Uri\AppData\Local\Temp\pip-build-3dj7ngjs\Pillow\

(.venv) C:\Uri\Speedy Net\Git\speedy-net [public]>pip install -r
requirements.txt

What is the problem? Our requirements file is here:
https://github.com/urievenchen/speedy-net/blob/master/requirements.txt

It doesn't fail with Python 3.5.2

*Uri Even-Chen*
[image: photo] Phone: +972-54-3995700
Email: uri at speedy.net
Website: http://www.speedysoftware.com/uri/en/
<http://www.facebook.com/urievenchen>  <http://plus.google.com/+urievenchen>
  <http://www.linkedin.com/in/urievenchen>  <http://github.com/urievenchen>
<http://twitter.com/urievenchen>


From python at lucidity.plus.com  Tue Jan  3 08:25:38 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 04 Jan 2017 01:25:38 +1200
Subject: Screwing Up looping in Generator
Message-ID: <3009695678@f38.n261.z1.binkp.net>

Hi,

On 04/01/17 01:12, Deborah Swanson wrote:
> The main reason you might want to catch the StopIteration exception is
> to do something else before your code simply stops running. If all
> you're doing is run a generator til it's out of gas, and that's all you
> want it to do, then there's no need to catch anything.

Ah! OK, I see where the lines are being crossed now ;) Although StopIteration 
is an exception, it is something that the 'for/iter' machinery handles for you 
under the covers. Each 'for' statement effectively has a 'try' block around it 
that catches 'StopIteration' and just terminates that particular 'for' loop and 
continues on with the remainder of your script.

Raising a 'StopIteration' is an internal mechanism used to determine when an 
iterator (i.e., the thing a 'for' loop is looping over) has exhausted itself. 
It's not something a regular user is ever expected to know about let alone 
catch.

When execution falls out of the bottom of a generator, StopIteration is raise 
(compared to a regular function or method returning 'None').

E.



From python at deborahswanson.net  Tue Jan  3 08:32:12 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 04 Jan 2017 01:32:12 +1200
Subject: Clickable hyperlinks
Message-ID: <4225562807@f38.n261.z1.binkp.net>

Steven D'Aprano wrote, on January 03, 2017 9:40 PM
>
> On Wednesday 04 January 2017 15:46, Deborah Swanson wrote:
>
> > Steven D'Aprano wrote, on January 03, 2017 8:04 PM
> [...]
> >> Of course you have to put quotes around them to enter them in your
> >> source code. We don't expect this to work:
> >>
> >>     print(Hello World!)
> >>
> >>
> >> you have to use a string literal with quotes:
> >>
> >>     print('Hello World!')
> >>
> >>
> >> Same for all of the above.
>
> > I didn't try printing them before, but I just did. Got:
> >
> >>>> print([Example](http://www.example.com)
> >
> > SyntaxError: invalid syntax  (arrow pointing at the colon)
>
> You missed the part where I said you have to put them in quotes.
>
> Like any other string in Python, you have to use quotation
> marks around it for
> Python to understand it as a string. None of these things will work:
>
> print( Hello World! )
>
> print( What do you want to do today? )
>
> print( 3 2 1 blast off )
>
> print( http://www.example.com )
>
>
> This isn't specific to print. This won't work either:
>
> message = Hello World!
>
> In *all* of these cases, you have to tell Python you're
> dealing with a string,
> and you do that with quotation marks:
>
> message = "Hello World!"
> print( 'What do you want to do today?' )
> count_down = '3 2 1 blast off'
> url = 'http://www.example.com'
>
>
>
>
> --
> Steven

Thanks, Steven. Yes, of course if you want to print strings you must enclose 
them in quotes. I think you learn that in Week 1 of any introductory course on 
Python.

But we aren't trying to print strings here, the point is to produce clickable 
links. I didn't enclose them with quotes because I didn't see any point in 
printing plain text when I wanted clickable links. I actually didn't understand 
why you thought I should print them, but it never would have occurred to me 
that you wanted me to print out a bunch of silly plain text strings, apparently 
just for the heck of it.

At this point, if I pursue this any farther, it will be to look into how 
Firefox takes webpage titles and urls out of its sqlite database and makes 
objects you can click on to open the webpages. That's the basic technology I'd 
need to find a way to talk (write) python into doing.

If it's even worth it. On a practical level it's not worth it, way too much 
work for the teensy advantage of having it to use. It might be some giggles to 
figure out how to do it and maybe I will sometime just for funsies.

My original question was whether python had anything to provide this 
functionality, and the answer appears to be a resounding NO!!!

Answer received, and thanks to all who contributed.



From python at mrabarnett.plus.com  Tue Jan  3 09:05:34 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Wed, 04 Jan 2017 02:05:34 +1200
Subject: Hey, I'm new to python so don't judge.
Message-ID: <3183934424@f38.n261.z1.binkp.net>

On 2017-01-04 01:37, Callum Robinson wrote:
> On Wednesday, January 4, 2017 at 12:49:28 PM UTC+13, Callum Robinson wrote:
>> Im doing a new task from my teacher but i can't seem to find what is wrong
with this code. Can anyone help?
>>
>> #mynumber.py
>> # this game uses a home made function
>> import random
>>
>> #think of a number
>> computer_number = number.randint(1,100)
>>
>> #create the function is_same()
>> def is_same(target, number:
>>         if target == number:
>>             result="win"
>>         elif target > number:
>>             result="low"
>>         else:
>>             result="high"
>>         return result
>>
>> # start the game
>> print("hello. \nI have thought of a number between 1 and 100.")
>>
>> #collect the user's guess as an interger
>> guess = int(input("Can you guess it? "))
>> #Use our function
>> higher_or_lower = is_same(computer_number, guess)
>> #run the game untill the user is correct
>> while higher_or_lower != "win"
>>     if higher_or_lower == "to low"
>>          guess = int(input("Sorry, you are too low. Try again."))
>>     else:
>>         guess = int(input("Sorry your are too high. Try again."))
>>
>>     higher_or_lower = is_same(computer_number, guess)
>>
>> #end of game
>> input("Correct!\nWell Done\n\n\nPress RETURN to exit.")
>
> Hey again, i'm sorry for bothering you with so many questions i just did not
want to keep asking my teacher who is on holiday these.
>
> I have another issue where the code runs but i can guess every number from
1-100 but it always says Sorry your are too high. Try again. I don't understand 
what i have done to cause this.
>
What values can 'is_same' return?

Which of those values are you checking for in the loop?



From python at lucidity.plus.com  Tue Jan  3 09:09:40 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 04 Jan 2017 02:09:40 +1200
Subject: How Best to Coerce Python Objects to Integers?
Message-ID: <517822311@f38.n261.z1.binkp.net>

On 04/01/17 01:10, Steve D'Aprano wrote:
> On Wed, 4 Jan 2017 11:22 am, Erik wrote:
>> What he *should* have done is just validated his input strings before
>> presenting the string to int() - i.e., process the input with knowledge
>> that is specific to the problem domain before calling the
>> general-purpose function.
>
> That's the Look Before You Leap solution. But in this case, given the
> scenario described (a text file with a few typos), the best way is to ask
> for forgiveness rather than permission:

Yes, probably, in this case ;)

OK, in the case where the function you're calling is sane (and Python's int() 
is - it won't blindly accept "0x101" as a hex value, for example) then it's 
probably right that leaping first and then, on failure, processing the value 
and leaping again is the right thing to do.

[I tend to work in an environment where things I'm calling may not be sane (and 
in some cases I may never know), so I will usually consider LBYL as a way of 
CMA ;)].

In this whole discussion there has been no mention of what happens when the 
function returns None, though.

> Another thought: if he is receiving human generated input, there is an
> argument to be made for accepting "look alikes" -- e.g. maybe the data was
> entered by Aunt Tilly, who was a typist in the 1960s and can't break the
> habit of using l or I interchangeably for 1, and O for 0.

Sure - and that's what I meant by processing the string according to his 
problem "domain". If he has Aunt Tillys doing his data input, then l->1 and 
0->O may be a reasonable thing (I recently did a project where things like 
0-> converting Icelandic's Eth and Thorn runic letters to 'D' and 'P' - though 
0-> lly wrong ;) - was a reasonable character translation because that's what 
0-> le actually typed in).

E.



From python at lucidity.plus.com  Tue Jan  3 09:35:34 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 04 Jan 2017 02:35:34 +1200
Subject: Hey, I'm new to python so don't judge.
Message-ID: <595817138@f38.n261.z1.binkp.net>

On 04/01/17 02:24, Callum Robinson wrote:
> On Wednesday, January 4, 2017 at 3:05:48 PM UTC+13, MRAB wrote:
>> What values can 'is_same' return?
>>
>> Which of those values are you checking for in the loop?
>
> I'm sorry but i do not completely understand what you are stating

You need to think about the specific things (their type, their exact values) 
that your functions might return. Printing some trace output is a classic way 
of debugging your program. If, after this line:

 >>>> higher_or_lower = is_same(computer_number, guess)

... you added:

print (higher_or_lower)

... what values do you then see being output? How will those values be 
processed by the conditions you see that work on the "higher_or_lower" 
variable?

E.



From jorge.conrado at cptec.inpe.br  Tue Jan  3 09:45:29 2017
From: jorge.conrado at cptec.inpe.br (jorge.conrado at cptec.inpe.br)
Date: Tue, 03 Jan 2017 12:45:29 -0200
Subject: Numpy error
Message-ID: <f55d299c0c8105833cb5d05ef271b768@cptec.inpe.br>



Hi,


I alredy used Python and now I have the message:

import numpy as np
Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
   File 
"/home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-packages/numpy-1.8.0-py2.7-linux-x86_64.egg/numpy/__init__.py", 
line 153, in <module>
     from . import add_newdocs
   File 
"/home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-packages/numpy-1.8.0-py2.7-linux-x86_64.egg/numpy/add_newdocs.py", 
line 13, in <module>
     from numpy.lib import add_newdoc
   File 
"/home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-packages/numpy-1.8.0-py2.7-linux-x86_64.egg/numpy/lib/__init__.py", 
line 18, in <module>
     from .polynomial import *
   File 
"/home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-packages/numpy-1.8.0-py2.7-linux-x86_64.egg/numpy/lib/polynomial.py", 
line 19, in <module>
     from numpy.linalg import eigvals, lstsq, inv
   File 
"/home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-packages/numpy-1.8.0-py2.7-linux-x86_64.egg/numpy/linalg/__init__.py", 
line 50, in <module>
     from .linalg import *
   File 
"/home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-packages/numpy-1.8.0-py2.7-linux-x86_64.egg/numpy/linalg/linalg.py", 
line 29, in <module>
     from numpy.linalg import lapack_lite, _umath_linalg
ImportError: 
/home/conrado/Canopy/appdata/canopy-1.5.5.3123.rh5-x86_64/lib/libgfortran.so.3: 
version `GFORTRAN_1.4' not found (required by /lib64/liblapack.so.3)


I did:  pip istall --user numpy


Requirement already satisfied: numpy in 
/home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-packages/numpy-1.8.0-py2.7-linux-x86_64.egg


What can I do to solve this message.


Thanks,


Conrado


From flebber.crue at gmail.com  Tue Jan  3 09:54:25 2017
From: flebber.crue at gmail.com (Sayth Renshaw)
Date: Tue, 3 Jan 2017 06:54:25 -0800 (PST)
Subject: Screwing Up looping in Generator
Message-ID: <7c38d03e-566c-4d36-9e41-84f913b2e097@googlegroups.com>

Hi

This is simple, but its getting me confused.

I have a csv writer that opens a file and loops each line of the file for each file and then closes, writing one file.

I want to alter the behaviour to be a written file for each input file. I saw a roundrobin example however it failed for me as you cannot get len(generator) to use a while loop on.
it exhausts

should I use the same for again after the with open?

rootobs in this code is my generator and I am already looping it however 
def data_attr(roots):
    """Get the root object and iter items."""
    for file in rootobs:
        base = os.path.basename(file.name)
        write_to = os.path.join("output", os.path.splitext(base)[0] + ".csv")
        with open(write_to, 'w', newline='') as csvf:
            race_writer = csv.writer(csvf, delimiter=',')
            race_writer.writerow(
                ["meet_id", "meet_venue", "meet_date", "meet_rail",
                 ...
                 # other categories here
                 ...
                    "jockeysurname", "jockeyfirstname"])
            for xml_data in roots:
                ...
                # parsing code
                        for noms in race_child:
                            if noms.tag == 'nomination':
                                race_writer.writerow(
                                    [meet_id, meet_venue, meet_date,
                                     ...
                                    #parsing info removed
                                        noms.get("jockeyfirstname")])

Cheers
Sayth


From python at lucidity.plus.com  Tue Jan  3 10:11:26 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 04 Jan 2017 03:11:26 +1200
Subject: Hey, I'm new to python so don't judge.
Message-ID: <2093310810@f38.n261.z1.binkp.net>

On 04/01/17 02:47, Callum Robinson wrote:
> On Wednesday, January 4, 2017 at 3:35:53 PM UTC+13, Erik wrote:
> I did it and this is what it states when i run it
>
> hello.
> I have thought of a number between 1 and 100.
> Can you guess it?
> 5
> Low
> Sorry , you are too high. Try again.
>
> Does this mean the number i entered is to low but the code is still stating
it is to high?

The last code you posted will return "low", "high" or "win" from the 
"is_same()" function. How does that relate to the "Low" that you are now 
printing?

You must have changed something. If you are testing strings as return values 
then they must be _exactly_ the same - including case and spaces etc.

Always remember that your computer is an idiot. It's the fastest idiot that 
you'll ever know, and it could become your best friend. But it IS an idiot ;)

E.



From python at deborahswanson.net  Tue Jan  3 10:15:52 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 04 Jan 2017 03:15:52 +1200
Subject: Clickable hyperlinks
Message-ID: <158870337@f38.n261.z1.binkp.net>

Steve D'Aprano wrote, on January 04, 2017 2:09 AM
>
> On Wed, 4 Jan 2017 08:00 pm, Deborah Swanson wrote:
>
> [speaking of threading emails]
>
> > I suppose. Times change of course, which always suits some and not
> > others. Personally, I think putting messages that have different
> > titles all in one thread is a bad design, but as I've said
> a couple of
> > times now I intend to comply with the new rules. But compliance
> > doesn't imply agreement. I prefer the old system, which ordered
> > threads by titles, but there's obviously no pleasing
> everyone on this
> > issue.
>
> Indeed :-)
>
> However, as far as I am aware, the use of threading by
> following the In-Reply-To and References header lines goes
> back to at least 1982, which makes them pretty old, and
> certainly pre-dates Gmail and Outlook by many years. They're
> also official standards which ALL email programs are supposed
> to follow, so if Gmail and Outlook fail to follow the
> standard, well, I wouldn't be surprised. I don't absolutely
> know for a fact that threading in this way is older than
> threading by subject line, but I'm fairly confident that what
> you are calling the "new rules" are actually the much older rules.
>
> Are there any old-timers here who were using email prior to
> 1982 that would care to comment?
>
>
> Here's a discussion by Jamie Zawinski, who wrote Netscape
> Navigator, before it became Mozila and Firefox, so he knows
> what he's talking about:
>
https://www.jwz.org/doc/threading.html


The concept here is not so much that people start a new topic and change the 
subject, but that sometimes the topic just naturally evolves to the point that 
a change in subject is sensible. Take this thread for example: the topic has 
drifted from "Clickable hyperlinks" to talking about email threading. I should 
be able to change the subject without breaking the
thread:

Clickable hyperlinks
+- RE: Clickable hyperlinks
?  +- Re: RE: Clickable hyperlinks
?  L- RE: Clickable hyperlinks
?     L- Threading [was Re: Clickable hyperlinks]
?        L- Re: Threading
+- RE: Clickable hyperlinks
L- Re: Clickable hyperlinks


Adding a "Re:" or "RE" to the subject doesn't change the thread, and neither 
does changing the subject line in a more substantial way.

Of course, I can always *choose* to sort by subject line, or date. Personally I 
hardly ever sort by thread, so it is no skin off my nose what you do. But when 
you hit "Reply" to a message, you inherit the "Reference" and "In-Reply-To" 
headers from the previous message, so at least some people will see it threaded 
in an existing thread rather than starting a brand new one.




--
Steve
"Cheer up," they said, "things could be worse." So I cheered up, and sure 
enough, things got worse.

Interesting history lesson. I actually wouldn't know which came first, since 
I've only been online since 1992 (offline computing since 1972). I do know that 
I've been on a lot of mailing lists like this one since 1992 (remember 
Fidonet?), some with actively posting members in the thousands. And I have 
never heard anyone whine and complain about threading issues that had anything 
to do with the message title until yesterday.

So it goes. I'll repeat again that I'll comply with the rules of this group 
that are brand spanking new to me, and I've been around a corner or two.



From python at deborahswanson.net  Tue Jan  3 10:25:34 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 04 Jan 2017 03:25:34 +1200
Subject: Clickable hyperlinks
Message-ID: <1117208239@f38.n261.z1.binkp.net>

Steve D'Aprano wrote, on January 04, 2017 2:20 AM
>
> On Wed, 4 Jan 2017 03:46 pm, Deborah Swanson wrote:
>
> > As I've mentioned in other posts on this thread, I'm now
> thinking that
> > I need to write a class to do this, and find out how
> Firefox and url
> > aware terminals in Linux do it. There must be a way.
>
>
> A GUI application can interpret text any way it chooses.
> Firefox takes a HTML file and renders it, using whatever GUI
> library it chooses. That GUI library understands that text like:
>
> <b>Hello World!</b>
>
> should be shown in bold face, and text like:
>
> <a href="http://www.example.com">Example</a>
>
> should be shown as the word "Example" underlined and in some
> colour, and when you click on it the browser will navigate to
> the URL given. Firefox can do this because it controls the
> environment it runs in.
>
> Same for Excel, which also controls the environment it runs in.
>
> That's *not* the case for Python, which is at the mercy of
> whatever console or terminal application it is running in.
>
> However, you can use Python to write GUI applications. Then it becomes
> *your* responsibility to create the window, populate it with
> any buttons or text or scroll bars you want, and you can
> choose to interpret text any way you like -- including as
> clickable Hyperlinks.
>
> The bottom line is, there is no "a way" to do this. There are
> a thousand, ten thousand, ways to do it. Every web browser,
> every terminal, every URL-aware application, can choose its
> own way to do it. There's no one single way that works
> everywhere, but if you are working in a console or terminal,
> just printing the URL is likely to be interpreted by the
> console as a clickable link:
>
> print("http://www.example.com")
>
>
>
>
> --
> Steve
> "Cheer up," they said, "things could be worse." So I cheered
> up, and sure enough, things got worse.

I can appreciate all that and pretty much knew most of it already. At this 
point I'm not so much concerned with how to put characters on a white space 
that are clickable, we've pretty much established at least a couple dozen 
messages ago that there's nothing for python to get hold of there because of 
the vast number of places people might want to put clickable links. (I actually 
read every message on a thread that interests me enough to participate.)

I think the entry point to this problem is to find out how to connect to the 
internet when you click that link. Then I think the nuts and bolts of what 
symbols to put where for a particular target would fall into place.



From python at deborahswanson.net  Tue Jan  3 10:43:02 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 04 Jan 2017 03:43:02 +1200
Subject: Clickable hyperlinks
Message-ID: <3628262856@f38.n261.z1.binkp.net>

Steve D'Aprano wrote, on January 04, 2017 2:39 AM
>
> On Wed, 4 Jan 2017 08:32 pm, Deborah Swanson wrote:
>
> > Thanks, Steven. Yes, of course if you want to print strings
> you must
> > enclose them in quotes. I think you learn that in Week 1 of any
> > introductory course on Python.
> >
> > But we aren't trying to print strings here, the point is to produce
> > clickable links. I didn't enclose them with quotes because I didn't
> > see any point in printing plain text when I wanted
> clickable links. I
> > actually didn't understand why you thought I should print
> them, but it
> > never would have occurred to me that you wanted me to print out a
> > bunch of silly plain text strings, apparently just for the
> heck of it.
>
> What we have here is a failure to communicate :-)
>
> I apologise for ruffling your feathers, but its difficult to
> judge another person's level of knowledge. In someways you're
> obviously quite knowledgeable about Python, but in other ways
> you're still learning (as we all are!) and I'm afraid I may
> have misjudged exactly what your level of knowledge was.
> Sorry about that.
>
> I'm not suggesting that you print "silly plain text strings"
> just for the heck of it. You've asked how to get a clickable
> link using Python. There is only one way I know of to get a
> clickable link using Python:
>
> Write out a link as plain text to another application which
> then interprets the plain text as a clickable link.
>
> You *might* be able to get clickable links in Python by
> writing an entire GUI application, using (say) the tkinter
> library, or one of the third-party GUI libraries like
> wxPython, kivy, pyqt, or others, but I haven't a clue how.
> But even there, your links will start off as text, which
> means you will still need to surround them with quotes to
> make them strings.
>
>
> Aside: you've actually raised a fascinating question. I
> wonder whether there are any programming languages that
> understand URLs as native data types, so that *source code*
> starting with http:// etc is understood in the same way that
> source code starting with [ is seen as a list or { as a dict?
>
>
> But back to your problem: short of writing you own GUI
> application, in which case you can do *anything you like*, you can:
>
> - write out a HTML file containing the URLs you want, in <a
> href= ... </a> tags, then open the HTML file in a web browser
> and let the web browser interpret the HTML tags as clickable links;
>
>
> - write out an Excel spreadsheet, using whatever format Excel
> expects, open the spreadsheet in Excel, and let Excel
> interpret the mystery format as a clickable link;
>
> - print the URL to the console, and see if the console is
> smart enough to interpret it as a clickable link.
>
>
> I'm sorry that I can't give you a one-sentence answer "just
> use such-and-such a function, that does exactly what you want
> in a platform-independent manner" :-(
>
>
>
>
> --
> Steve
> "Cheer up," they said, "things could be worse." So I cheered
> up, and sure enough, things got worse.

Well, well. People mix and people misunderstand and misjudge each other. It's 
the way of things with people. I just needed to tell you how it all looked from 
my side.  So are we done with that?  I certainly hope so.

I'm quite well aware by now that there is no one-sentence answer to my original 
question, if there's any coherent answer at all. Them's the breaks. Live with 
it or live without it, it doesn't care.

I do appreciate the education I've gotten on this thread about the issues 
involved. But I rather imagine that near term anyway, I'll only be pondering it 
now and then, and maybe poking around a bit. Who knows, maybe I'll eventually 
invent the solution and make my first million dollars from it.  haha, yeah 
right.

So it goes.


Deborah



From __peter__ at web.de  Tue Jan  3 10:57:26 2017
From: __peter__ at web.de (Peter Otten)
Date: Tue, 03 Jan 2017 16:57:26 +0100
Subject: trouble with cmd.Cmd and prompting
References: <v7cm6chmd32it422kh3doh6a6k6d1inq4n@4ax.com>
 <20170103063903.GA63893@cskk.homeip.net>
Message-ID: <o4ghl4$ejg$1@blaine.gmane.org>

Cameron Simpson wrote:

> On 03Jan2017 00:14, Dennis Lee Bieber <wlfraed at ix.netcom.com> wrote:
>>On Tue, 3 Jan 2017 11:33:15 +1100, Cameron Simpson <cs at zip.com.au>
>>declaimed the following:
>>>I'm using cmd.Cmd to write a little FTP-like command line to interface to
>>>a storage system of mine and encountering weird behaviour. When I enter a
>>>command the next prompt appears _before_ the associated operation runs,
>>>or so it appears.
>><SNIP>
>>>Has anyone seen this kind of thing before?
>>
>>Haven't used the module but there is something I find intriguing in the
>>help system
>>-=-=-=-=-
>> Cmd.precmd(line)
>>    Hook method executed just before the command line is interpreted, but
>>after the input prompt is generated and issued.
>>-=-=-=-=-
>>"... AFTER the input prompt is ... issued"
>>
>>I don't know, but that sure sounds to me like the cmd object tends to
>>process one line behind... Though that behavior is not shown in the turtle
>>example in the help system.
> 
> Hmm. Interesting. I had read that text to imply (based on what I imagined
> _should_ happen) that the flow of control went:
> 
>   cmdloop:
>     issue prompt>
>     line=input()  # or readline
>     line=precmd(line)
>     stop=onecmd(line) # which calls do_blah...
>     stop=postcmd(stop,line)
>     if stop:
>       break
> 
> but your reading of it suggests that this is possible:
> 
>   issue prompt>
>   cmdloop:
>     line=input()  # or readline
>     issue prompt>
>     line=precmd(line)
>     stop=onecmd(line) # which calls do_blah...
>     stop=postcmd(stop,line)
>     if stop:
>       break
> 
> The text for Cmd.cmdloop starts with this:
> 
>   Repeatedly issue a prompt, accept input, parse an initial prefix off the
>   received input, and dispatch to action methods, passing them the
>   remainder of the line as argument.
> 
> which argues for the former, and was what I naively expected.
> 
> I guess I'd better dig out the source; I dislike going that far, not
> merely out of laziness, but also because the source is not the spec.
> 
> Thanks for the suggestion,
> Cameron Simpson <cs at zip.com.au>

I don't believe Dennis' reading of the docs is correct, and the relevant 
part of the source (Python 3.4) does not show anything to support it:

            while not stop:
                if self.cmdqueue:
                    line = self.cmdqueue.pop(0)
                else:
                    if self.use_rawinput:
                        try:
                            line = input(self.prompt)
                        except EOFError:
                            line = 'EOF'
                    else:
                        self.stdout.write(self.prompt)
                        self.stdout.flush()
                        line = self.stdin.readline()
                        if not len(line):
                            line = 'EOF'
                        else:
                            line = line.rstrip('\r\n')
                line = self.precmd(line)
                stop = self.onecmd(line)
                stop = self.postcmd(stop, line)
            self.postloop()

Is there something asynchronous in your command? Perhaps you can post a 
minimal runnable example that shows the odd behaviour.



From best_lay at yahoo.com  Tue Jan  3 11:00:56 2017
From: best_lay at yahoo.com (Wildman)
Date: Tue, 03 Jan 2017 10:00:56 -0600
Subject: learning and experimenting python.
References: <6886d439-751c-42d2-adf2-fbf494221d48@googlegroups.com>
 <o47q7t$4jq$1@dont-email.me>
 <58678152$0$1622$c3e8da3$5496439d@news.astraweb.com>
 <d5a48cd6-fd0e-45eb-bac6-0bf7dc131250@googlegroups.com>
 <CALwzid=98ggNQiLNe0sVMbxN2wQ-zGecFvQf-DZ4_JRTjNZWuQ@mail.gmail.com>
 <o4beb3$8h4$1@blaine.gmane.org>
 <mailman.104.1483291835.2395.python-list@python.org>
 <c4d371a9-0d00-4a98-8daf-894811a9b72d@googlegroups.com>
 <W-GdnbGl-7FncPTFnZ2dnUU7-IGdnZ2d@giganews.com>
 <aa6a1985-c932-4e05-99e0-1ce47c29e6d0@googlegroups.com>
 <OIidnYnqF8UJDvfFnZ2dnUU7-SOdnZ2d@giganews.com>
 <586B27B5.9040107@stoneleaf.us>
 <mailman.137.1483417523.2395.python-list@python.org>
Message-ID: <MJmdnU610OUlV_bFnZ2dnUU7-b2dnZ2d@giganews.com>

On Mon, 02 Jan 2017 20:25:25 -0800, Ethan Furman wrote:

> On 01/02/2017 09:53 AM, Wildman via Python-list wrote:
> 
> [rude ascii art omitted]
> 
> That is a completely inappropriate response.

Yes it was.  I tend to get upset when told to shut up and
go away for no good reason.

-- 
<Wildman> GNU/Linux user #557453
The cow died so I don't need your bull!


From redstone-cold at 163.com  Tue Jan  3 11:15:06 2017
From: redstone-cold at 163.com (iMath)
Date: Wed, 04 Jan 2017 04:15:06 +1200
Subject: Introducing my Python/PyQt5 powered Bing wallpaper open source project
Message-ID: <1309505310@f38.n261.z1.binkp.net>

Hello everyone ,
I'd like to introduce my Python/PyQt5 powered Bing wallpaper open source 
project.
? ?

BingNiceWallpapers
https://github.com/redstoneleo/BingNiceWallpapers

BingNiceWallpapers can get background images from 
http://www.bing.com/?mkt=zh-CN and set them as your desktop wallpaper by just a 
single click on system tray icon.

For Windows binary installer and more information, please refer to 
http://mathjoy.lofter.com/post/42208d_7cabcf7 (written in simplified Chinese)

Features

Changing wallpaper in a single click on system tray icon or after a specified 
time interval
Windows and Linux Gnome desktop support Delete or save the current wallpaper


Welcome to help with the project !



From python at lucidity.plus.com  Tue Jan  3 11:22:58 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 04 Jan 2017 04:22:58 +1200
Subject: Hey, I'm new to python so don't judge.
Message-ID: <2440616603@f38.n261.z1.binkp.net>

On 04/01/17 03:25, Steven D'Aprano wrote:
> On Wednesday 04 January 2017 12:25, Callum Robinson wrote:
>
>> Hey man thanks, the sad thing is i have no idea why i put that in. I must be
>> having a terrible day.
>
> Don't worry about it. The difference between a beginner and an expert is
*not*
> that experts make fewer mistakes, but that experts know how to fix those
> mistakes so quickly that they don't even notice them.

Hmm. An expert at what? Telling a beginner how to spell something is not the 
same as coaxing that same beginner to think about something or approach a 
problem from a particular angle and come to their own solution. We all could 
have told him the answer up-front. What has that achieved?

E.



From songofacandy at gmail.com  Tue Jan  3 11:35:40 2017
From: songofacandy at gmail.com (INADA Naoki)
Date: Wed, 4 Jan 2017 01:35:40 +0900
Subject: pip install -r requirements.txt fails with Python 3.6 on Windows
 10
In-Reply-To: <CAMQ2MsFS-YHajpia_Q_s6dses2MAj7zeMir69CcPQ9R6Tr1MvQ@mail.gmail.com>
References: <CAMQ2MsFS-YHajpia_Q_s6dses2MAj7zeMir69CcPQ9R6Tr1MvQ@mail.gmail.com>
Message-ID: <CAEfz+Ty-NKKfDfw-VrjYbnBHRrbxX0_VFw=DEFZxz6zy08sYVg@mail.gmail.com>

Pillow 3.4.2 provides binary wheel for Python 3.5, but not for 3.6.

So your pip can just install wheel on Python 3.5, but it is required to build
on Python 3.6.  And your machine doesn't have zlib which is required
to build Pillow.

Easiest solution may just update your requirements to Pillow==4.0.0.
Pillow 4.0.0 provides binary wheel for Python 3.6, from 2017-01-02.
https://pypi.python.org/pypi/Pillow/4.0.0


On Tue, Jan 3, 2017 at 10:19 PM, Uri Even-Chen <uri at speedy.net> wrote:
> (.venv) C:\Uri\Speedy Net\Git\speedy-net [public]>pip install -r
> requirements.txt
> Requirement already satisfied: Django==1.10.4 in c:\uri\speedy
> net\git\speedy-net [public]\.venv\lib\site-packages (from -r
> requirements.txt (line 2))
> Requirement already satisfied: django-crispy-forms==1.6.1 in c:\uri\speedy
> net\git\speedy-net [public]\.venv\lib\site-packages (from -r
> requirements.txt (line 3))
> Requirement already satisfied: django-debug-toolbar==1.6 in c:\uri\speedy
> net\git\speedy-net [public]\.venv\lib\site-packages (from -r
> requirements.txt (line 4))
> Requirement already satisfied: django-environ==0.4.1 in c:\uri\speedy
> net\git\speedy-net [public]\.venv\lib\site-packages (from -r
> requirements.txt (line 5))
> Requirement already satisfied: django-friendship==1.5.0 in c:\uri\speedy
> net\git\speedy-net [public]\.venv\lib\site-packages (from -r
> requirements.txt (line 6))
> Requirement already satisfied: django-modeltranslation==0.12 in
> c:\uri\speedy net\git\speedy-net [public]\.venv\lib\site-packages (from -r
> requirements.txt (line 7))
> Requirement already satisfied: factory-boy==2.8.1 in c:\uri\speedy
> net\git\speedy-net [public]\.venv\lib\site-packages (from -r
> requirements.txt (line 8))
> Requirement already satisfied: Faker==0.7.7 in c:\uri\speedy
> net\git\speedy-net [public]\.venv\lib\site-packages (from -r
> requirements.txt (line 9))
> Collecting Pillow==3.4.2 (from -r requirements.txt (line 10))
>   Using cached Pillow-3.4.2.tar.gz
> Requirement already satisfied: python-dateutil==2.6.0 in c:\uri\speedy
> net\git\speedy-net [public]\.venv\lib\site-packages (from -r
> requirements.txt (line 11))
> Collecting rules==1.2 (from -r requirements.txt (line 12))
>   Using cached rules-1.2.tar.gz
> Requirement already satisfied: six==1.10.0 in c:\uri\speedy
> net\git\speedy-net [public]\.venv\lib\site-packages (from -r
> requirements.txt (line 13))
> Collecting sorl-thumbnail==12.4a1 (from -r requirements.txt (line 14))
>   Using cached sorl_thumbnail-12.4a1-py2.py3-none-any.whl
> Requirement already satisfied: sqlparse==0.2.2 in c:\uri\speedy
> net\git\speedy-net [public]\.venv\lib\site-packages (from -r
> requirements.txt (line 15))
> Installing collected packages: Pillow, rules, sorl-thumbnail
>   Running setup.py install for Pillow ... error
>     Complete output from command "c:\uri\speedy net\git\speedy-net
> [public]\.venv\scripts\python.exe" -u -c "import setuptools,
> tokenize;__file__='C:\\Users\\Uri\\AppData\\Local\\Temp\\pip-build-3dj7ngjs\\Pillow\\setup.py';f=getattr(tokenize,
> 'open', open)(__file__);code=f.read().replace('\r\n',
> '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record
> C:\Users\Uri\AppData\Local\Temp\pip-1464cmd1-record\install-record.txt
> --single-version-externally-managed --compile --install-headers
> "c:\uri\speedy net\git\speedy-net
> [public]\.venv\include\site\python3.6\Pillow":
>     Single threaded build for windows
>     running install
>     running build
>     running build_py
>     creating build
>     creating build\lib.win32-3.6
>     creating build\lib.win32-3.6\PIL
>     copying PIL\BdfFontFile.py -> build\lib.win32-3.6\PIL
>     copying PIL\BmpImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\BufrStubImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\ContainerIO.py -> build\lib.win32-3.6\PIL
>     copying PIL\CurImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\DcxImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\DdsImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\EpsImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\ExifTags.py -> build\lib.win32-3.6\PIL
>     copying PIL\features.py -> build\lib.win32-3.6\PIL
>     copying PIL\FitsStubImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\FliImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\FontFile.py -> build\lib.win32-3.6\PIL
>     copying PIL\FpxImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\FtexImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\GbrImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\GdImageFile.py -> build\lib.win32-3.6\PIL
>     copying PIL\GifImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\GimpGradientFile.py -> build\lib.win32-3.6\PIL
>     copying PIL\GimpPaletteFile.py -> build\lib.win32-3.6\PIL
>     copying PIL\GribStubImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\Hdf5StubImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\IcnsImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\IcoImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\Image.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageChops.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageCms.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageColor.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageDraw.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageDraw2.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageEnhance.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageFile.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageFilter.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageFont.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageGrab.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageMath.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageMode.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageMorph.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageOps.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImagePalette.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImagePath.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageQt.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageSequence.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageShow.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageStat.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageTk.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageTransform.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImageWin.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\ImtImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\IptcImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\Jpeg2KImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\JpegImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\JpegPresets.py -> build\lib.win32-3.6\PIL
>     copying PIL\McIdasImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\MicImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\MpegImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\MpoImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\MspImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\OleFileIO.py -> build\lib.win32-3.6\PIL
>     copying PIL\PaletteFile.py -> build\lib.win32-3.6\PIL
>     copying PIL\PalmImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\PcdImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\PcfFontFile.py -> build\lib.win32-3.6\PIL
>     copying PIL\PcxImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\PdfImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\PixarImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\PngImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\PpmImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\PsdImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\PSDraw.py -> build\lib.win32-3.6\PIL
>     copying PIL\PyAccess.py -> build\lib.win32-3.6\PIL
>     copying PIL\SgiImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\SpiderImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\SunImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\TarIO.py -> build\lib.win32-3.6\PIL
>     copying PIL\TgaImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\TiffImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\TiffTags.py -> build\lib.win32-3.6\PIL
>     copying PIL\WalImageFile.py -> build\lib.win32-3.6\PIL
>     copying PIL\WebPImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\WmfImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\XbmImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\XpmImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\XVThumbImagePlugin.py -> build\lib.win32-3.6\PIL
>     copying PIL\_binary.py -> build\lib.win32-3.6\PIL
>     copying PIL\_tkinter_finder.py -> build\lib.win32-3.6\PIL
>     copying PIL\_util.py -> build\lib.win32-3.6\PIL
>     copying PIL\__init__.py -> build\lib.win32-3.6\PIL
>     running egg_info
>     writing Pillow.egg-info\PKG-INFO
>     writing dependency_links to Pillow.egg-info\dependency_links.txt
>     writing top-level names to Pillow.egg-info\top_level.txt
>     warning: manifest_maker: standard file '-c' not found
>
>     reading manifest file 'Pillow.egg-info\SOURCES.txt'
>     reading manifest template 'MANIFEST.in'
>     warning: no files found matching '*.sh'
>     no previously-included directories found matching 'docs\_static'
>     warning: no previously-included files found matching '.coveragerc'
>     warning: no previously-included files found matching '.editorconfig'
>     warning: no previously-included files found matching '.landscape.yaml'
>     warning: no previously-included files found matching 'appveyor.yml'
>     warning: no previously-included files found matching 'build_children.sh'
>     warning: no previously-included files found matching 'tox.ini'
>     warning: no previously-included files matching '.git*' found anywhere
> in distribution
>     warning: no previously-included files matching '*.pyc' found anywhere
> in distribution
>     warning: no previously-included files matching '*.so' found anywhere in
> distribution
>     writing manifest file 'Pillow.egg-info\SOURCES.txt'
>     copying PIL\OleFileIO-README.md -> build\lib.win32-3.6\PIL
>     running build_ext
>     Traceback (most recent call last):
>       File "<string>", line 1, in <module>
>       File
> "C:\Users\Uri\AppData\Local\Temp\pip-build-3dj7ngjs\Pillow\setup.py", line
> 753, in <module>
>         zip_safe=not debug_build(), )
>       File
> "C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\core.py",
> line 148, in setup
>         dist.run_commands()
>       File
> "C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\dist.py",
> line 955, in run_commands
>         self.run_command(cmd)
>       File
> "C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\dist.py",
> line 974, in run_command
>         cmd_obj.run()
>       File "c:\uri\speedy net\git\speedy-net
> [public]\.venv\lib\site-packages\setuptools\command\install.py", line 61,
> in run
>         return orig.install.run(self)
>       File
> "C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\command\install.py",
> line 545, in run
>         self.run_command('build')
>       File
> "C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\cmd.py",
> line 313, in run_command
>         self.distribution.run_command(command)
>       File
> "C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\dist.py",
> line 974, in run_command
>         cmd_obj.run()
>       File
> "C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\command\build.py",
> line 135, in run
>         self.run_command(cmd_name)
>       File
> "C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\cmd.py",
> line 313, in run_command
>         self.distribution.run_command(command)
>       File
> "C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\dist.py",
> line 974, in run_command
>         cmd_obj.run()
>       File
> "C:\Users\Uri\AppData\Local\Programs\Python\Python36-32\lib\distutils\command\build_ext.py",
> line 339, in run
>         self.build_extensions()
>       File
> "C:\Users\Uri\AppData\Local\Temp\pip-build-3dj7ngjs\Pillow\setup.py", line
> 521, in build_extensions
>         ' using --disable-%s, aborting' % (f, f))
>     ValueError: zlib is required unless explicitly disabled using
> --disable-zlib, aborting
>
>     ----------------------------------------
> Command ""c:\uri\speedy net\git\speedy-net
> [public]\.venv\scripts\python.exe" -u -c "import setuptools,
> tokenize;__file__='C:\\Users\\Uri\\AppData\\Local\\Temp\\pip-build-3dj7ngjs\\Pillow\\setup.py';f=getattr(tokenize,
> 'open', open)(__file__);code=f.read().replace('\r\n',
> '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record
> C:\Users\Uri\AppData\Local\Temp\pip-1464cmd1-record\install-record.txt
> --single-version-externally-managed --compile --install-headers
> "c:\uri\speedy net\git\speedy-net
> [public]\.venv\include\site\python3.6\Pillow"" failed with error code 1 in
> C:\Users\Uri\AppData\Local\Temp\pip-build-3dj7ngjs\Pillow\
>
> (.venv) C:\Uri\Speedy Net\Git\speedy-net [public]>pip install -r
> requirements.txt
>
> What is the problem? Our requirements file is here:
> https://github.com/urievenchen/speedy-net/blob/master/requirements.txt
>
> It doesn't fail with Python 3.5.2
>
> *Uri Even-Chen*
> [image: photo] Phone: +972-54-3995700
> Email: uri at speedy.net
> Website: http://www.speedysoftware.com/uri/en/
> <http://www.facebook.com/urievenchen>  <http://plus.google.com/+urievenchen>
>   <http://www.linkedin.com/in/urievenchen>  <http://github.com/urievenchen>
> <http://twitter.com/urievenchen>
> --
> https://mail.python.org/mailman/listinfo/python-list


From dan at tombstonezero.net  Tue Jan  3 13:07:04 2017
From: dan at tombstonezero.net (Dan Sommers)
Date: Wed, 04 Jan 2017 06:07:04 +1200
Subject: Clickable hyperlinks
References: <4238055976@f38.n261.z1.binkp.net>
Message-ID: <4221224472@f38.n261.z1.binkp.net>

On Wed, 04 Jan 2017 16:40:00 +1100, Steven D'Aprano wrote:

> On Wednesday 04 January 2017 15:46, Deborah Swanson wrote:
>
>> Steven D'Aprano wrote, on January 03, 2017 8:04 PM
> [...]
>>> Of course you have to put quotes around them to enter them in
>>> your source code.
>>> We don't expect this to work:
>>>
>>>     print(Hello World!)
>>>
>>> you have to use a string literal with quotes:
>>>
>>>     print('Hello World!')
>>>
>>> Same for all of the above.
>
>> I didn't try printing them before, but I just did. Got:
>>
>>>>> print([Example](http://www.example.com)
>>
>> SyntaxError: invalid syntax  (arrow pointing at the colon)
>
> You missed the part where I said you have to put them in quotes.

ObPython:  "When I've got these antlers on I am dictating and when I take them 
off I am not dictating."  :-)



From kevin.p.dwyer at gmail.com  Tue Jan  3 13:41:40 2017
From: kevin.p.dwyer at gmail.com (Kev Dwyer)
Date: Wed, 04 Jan 2017 06:41:40 +1200
Subject: Mutable global state and threads
Message-ID: <1468831840@f38.n261.z1.binkp.net>

Hello List,

I came across some threading code in Some Other place recently and wanted to 
sanity-check my assumptions.

The code (below) creates a number of threads; each thread takes the last (index 
-1) value from a global list of integers, increments it by one and appends the 
new value to the list.

The originator of the code expected that when all the threads completed, the 
list would be an ascending sequence of integers, for example if the original 
list was [0] and two threads mutated it twice each, the final state would be 
[0, 1, 2, 3, 4].

Here is a version of the code (slightly simplified and modified to allow 
changing the number of threads and mutations).


import sys
import threading


class myThread(threading.Thread):

    def __init__(self, nmutations):
        threading.Thread.__init__(self)
        self.nmutations = nmutations

    def run(self):
        mutate(self.nmutations)
        # print (L)
        return


def mutate(nmutations):
    n = nmutations
    while n:
        L.append(L[-1 ]+ 1)
        n -= 1
    return


def main(nthreads=2, nmutations=2):
    global L
    L = [0]
    threads = [myThread(nmutations) for i in range(nthreads)]
    for t in threads:
        t.start()
    for t in threads:
        t.join()
    print(L)
    assert L == list(range((nthreads * nmutations) + 1))

if __name__ == '__main__':
    nthreads, nmutations = int(sys.argv[1]), int(sys.argv[2])
    main(nthreads, nmutations)

Firstly, is it true that the statement

L.append(L[-1 ]+ 1)

is not atomic, that is the thread might evaluate L[-1] and then yield, allowing 
another thread to mutate L, before incrementing and appending?

Secondly, the original code printed the list at the end of a thread's run 
method to examine the state of the list.  I don't think this would work quite 
as expected, because the thread might yield after mutating the list but before 
printing, so the list could have been mutated before the print was executed.  
Is there a way to display the state of the list before any further mutations 
take place?

(Disclaimer: I understand that sanity, mutable global state and threads are 
unlikely bedfellows and so promise never to try anything like this in 
production code).

Cheers,

Kev



From chris.p.clark at ba.com  Tue Jan  3 13:55:06 2017
From: chris.p.clark at ba.com (Chris Clark)
Date: Tue, 3 Jan 2017 18:55:06 +0000
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
Message-ID: <3C10AD96D068B9F8.6D96E7A5-7712-484F-98D0-8CCAEF99FD72@mail.outlook.com>

Tried every python ide going, they either grind to a halt or just look messy.
Best one I ever used and stick with is drpython, years old, probably not maintained but does everything I want at a blistering speed and just looks perfect.





On Mon, Jan 2, 2017 at 11:41 AM +0000, "Antonio Caminero Garcia" <tonycamgar at gmail.com<mailto:tonycamgar at gmail.com>> wrote:


Hello, I am having a hard time deciding what IDE or IDE-like code editor should I use. This can be overwhelming.

So far, I have used Vim, Sublime, Atom, Eclipse with PyDev, Pycharm, IntelliJ with Python plugin.

The thing with the from-the-scratch full featured IDEs (Eclipse, IntelliJ, Pycharm) is that they look like a space craft dashboard and that unwarranted resources consumption and the unnecessary icons. I want my IDE to be minimalistic but powerful. My screen should be mostly ?made of code? as usually happens in Vim, Sublime or Atom. However, Pycharm is really cool and python oriented.

The problem with Vim is the learning curve, so I know the very basic stuff, but obviously not enough for coding and I do not have time to learn it, it is a pity because there are awesome plugins that turns Vim into a lightweight powerful IDE-like. So now it is not an option but I will reconsider it in the future, learning little by little. Also, I am not very fan GUI guy if the task can be accomplished through the terminal. However, I don?t understand why people underrate GUIs, that said I normally use shortcuts for the most frequent tasks and when I have to do something that is not that frequent then I do it with the mouse, for the latter case in vim you would need to look for that specific command every time.

Sublime is my current and preferred code editor. I installed Anaconda, Git integration and a couple of additional plugins that make sublime very powerful. Also, what I like about sublime compared to the full featured IDEs, besides the minimalism, is how you can perform code navigation back and forth so fast, I mean this is something that you can also do with the others but for some subjective reason I specifically love how sublime does it. The code completion in sublime I do not find it very intelligence, the SublimeCodeIntel is better than the one that Anaconda uses but the completions are not as verbose as in the IDEs.

Now, I am thinking about giving a try to Visual Studio Code Edition (take a look, it sounds good https://marketplace.visualstudio.com/items?itemName=donjayamanne.python). I need an editor for professional software development. What would you recommend to me?
--
https://mail.python.org/mailman/listinfo/python-list


This message is private and confidential and may also be legally privileged. If you have received this message in error, please email it back to the sender and immediately permanently delete it from your computer system. Please do not read, print, re-transmit, store or act in reliance on it or any attachments. British Airways may monitor email traffic data and also the content of emails, where permitted by law, for the purposes of security and staff training and in order to prevent or detect unauthorised use of the British Airways email system. Virus checking of emails (including attachments) is the responsibility of the recipient. British Airways Plc is a public limited company registered in England and Wales. Registered number: 1777777. Registered office: Waterside, PO Box 365, Harmondsworth, West Drayton, Middlesex, England, UB7 0GB. Additional terms and conditions are available on our website: www.ba.com

From tim at akwebsoft.com  Tue Jan  3 14:13:11 2017
From: tim at akwebsoft.com (Tim Johnson)
Date: Tue, 3 Jan 2017 10:13:11 -0900
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <ba923722-087d-4c13-aaf6-0950a370c27b@googlegroups.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
 <ba923722-087d-4c13-aaf6-0950a370c27b@googlegroups.com>
Message-ID: <20170103191311.GB18910@mail.akwebsoft.com>

* Antonio Caminero Garcia <tonycamgar at gmail.com> [170102 20:56]:
> Guys really thank you for your answers. Basically now I am more
> emphasizing in learning in depth a tool and get stick to it so I
> can get a fast workflow. Eventually I will learn Vim and its
> python developing setup, I know people who have been programming
> using Vim for almost 20 years and they did not need to change
> editor (that is really awesome). 

 Bye the way, one thing I like about the GUI based vim is that it
 supports tabs, where emacs does not.

 And check out the vim plugins for python....

 Good Luck!
-- 
Tim 
http://www.akwebsoft.com, http://www.tj49.com


From tim at akwebsoft.com  Tue Jan  3 14:15:44 2017
From: tim at akwebsoft.com (Tim Johnson)
Date: Wed, 04 Jan 2017 07:15:44 +1200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
Message-ID: <870104349@f38.n261.z1.binkp.net>

* Paul Rudin <paul.nospam at rudin.co.uk> [170103 23:17]:
> Tim Johnson <tim at akwebsoft.com> writes:
>
> > * Antonio Caminero Garcia <tonycamgar at gmail.com> [170102 20:56]:
> >> Guys really thank you for your answers. Basically now I am more
> >> emphasizing in learning in depth a tool and get stick to it so I
> >> can get a fast workflow. Eventually I will learn Vim and its
> >> python developing setup, I know people who have been programming
> >> using Vim for almost 20 years and they did not need to change
> >> editor (that is really awesome).
> >
> >  Bye the way, one thing I like about the GUI based vim is that it
> >  supports tabs, where emacs does not.
>
> M-x package-install tabbar
  :) Thank you. list-packages is my friend ...
--
Tim
http://www.akwebsoft.com, http://www.tj49.com



From python at deborahswanson.net  Tue Jan  3 14:46:16 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 11:46:16 -0800
Subject: Clickable hyperlinks
In-Reply-To: <001501d264e4$32189a80$27b23dae@sambora>
Message-ID: <001e01d265fa$0c639d50$27b23dae@sambora>

Excel has a formula:

=HYPERLINK(url,description)

that will put a clickable link into a cell.

Does python have an equivalent function? Probably the most common use
for it would be output to the console, similar to a print statement, but
clickable.



From python at deborahswanson.net  Tue Jan  3 14:57:31 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 11:57:31 -0800
Subject: Numpy error
In-Reply-To: <f55d299c0c8105833cb5d05ef271b768@cptec.inpe.br>
Message-ID: <002201d265fb$9eb870d0$27b23dae@sambora>

> ImportError: 
> /home/conrado/Canopy/appdata/canopy-1.5.5.3123.rh5-x86_64/lib/
> libgfortran.so.3: 
> version `GFORTRAN_1.4' not found (required by /lib64/liblapack.so.3)

Looks like you need to install the 'GFORTRAN_1.4' plugin into Canopy. I
don't know where you'll find it, but Canopy's main website would be a
good place to start. Or google "GFORTRAN_1.4 Canopy download".


jorge.conrado at cptec.inpe.br wrote, on January 03, 2017 6:45 AM:
> 
> Hi,
> 
> 
> I alredy used Python and now I have the message:
> 
> import numpy as np
> Traceback (most recent call last):
>    File "<stdin>", line 1, in <module>
>    File 
> "/home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-
> packages/numpy-1.8.0-py2.7-linux-x86_64.egg/numpy/__init__.py", 
> line 153, in <module>
>      from . import add_newdocs
>    File 
> "/home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-
> packages/numpy-1.8.0-py2.7-linux-x86_64.egg/numpy/add_newdocs.py", 
> line 13, in <module>
>      from numpy.lib import add_newdoc
>    File 
> "/home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-
> packages/numpy-1.8.0-py2.7-linux-x86_64.egg/numpy/lib/__init__.py", 
> line 18, in <module>
>      from .polynomial import *
>    File 
> "/home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-
> packages/numpy-1.8.0-py2.7-linux-x86_64.egg/numpy/lib/polynomial.py", 
> line 19, in <module>
>      from numpy.linalg import eigvals, lstsq, inv
>    File 
> "/home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-
> packages/numpy-1.8.0-py2.7-linux-x86_64.egg/numpy/linalg/__ini
> t__.py", 
> line 50, in <module>
>      from .linalg import *
>    File 
> "/home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-
> packages/numpy-1.8.0-py2.7-linux-x86_64.egg/numpy/linalg/linalg.py", 
> line 29, in <module>
>      from numpy.linalg import lapack_lite, _umath_linalg
> ImportError: 
> /home/conrado/Canopy/appdata/canopy-1.5.5.3123.rh5-x86_64/lib/
> libgfortran.so.3: 
> version `GFORTRAN_1.4' not found (required by /lib64/liblapack.so.3)
> 
> 
> I did:  pip istall --user numpy
> 
> 
> Requirement already satisfied: numpy in 
> /home/conrado/Enthought/Canopy_64bit/User/lib/python2.7/site-p
> ackages/numpy-1.8.0-py2.7-linux-x86_64.egg
> 
> 
> What can I do to solve this message.
> 
> 
> Thanks,
> 
> 
> Conrado
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 



From darcy at vex.net  Tue Jan  3 15:03:08 2017
From: darcy at vex.net (D'Arcy Cain)
Date: Wed, 04 Jan 2017 08:03:08 +1200
Subject: Clickable hyperlinks
Message-ID: <3051536369@f38.n261.z1.binkp.net>

Deborah - please trim your quoted text.

On 2017-01-04 04:32 AM, Deborah Swanson wrote:
> Thanks, Steven. Yes, of course if you want to print strings you must
> enclose them in quotes. I think you learn that in Week 1 of any
> introductory course on Python.

Closer to minute one.  When I investigated Python years ago the first thing I 
learned was;

  print "Hello, world"

> But we aren't trying to print strings here, the point is to produce
> clickable links. I didn't enclose them with quotes because I didn't see
> any point in printing plain text when I wanted clickable links. I

I'm not sure what your links are composed of but mine all look like sequences 
of characters or "strings."  It sounds like you are trying to make URL a first 
class type like strings. integers, floats, etc.  I can't think of any language 
that treats URLs as first class objects. Even HTML needs quotes:

   <A HREF="http://...">Go here</A>

> actually didn't understand why you thought I should print them, but it

You want to output them to something.  That often involves printing them to a 
particular handler.

> never would have occurred to me that you wanted me to print out a bunch
> of silly plain text strings, apparently just for the heck of it.

Is that really what you got from his message?

> At this point, if I pursue this any farther, it will be to look into how
> Firefox takes webpage titles and urls out of its sqlite database and
> makes objects you can click on to open the webpages. That's the basic
> technology I'd need to find a way to talk (write) python into doing.

I can assure you that FF prints the string at some point.  It may wrap it in 
HTML tags first but printing is what it does.  Also, the URLs are stored as 
strings.  SQLite has no URL type.  If it did then it would still store it as a 
string somewhere.  PostGreSQL would let you create a URL type if you wanted but 
you would still need to wrap it in quotes
(single in this case) when you created the entry.

> If it's even worth it. On a practical level it's not worth it, way too
> much work for the teensy advantage of having it to use. It might be some
> giggles to figure out how to do it and maybe I will sometime just for
> funsies.

In all the messages in this thread I still don't understand what this "teensy 
advantage" is supposed to be.  Do you want to be able to do this:

   make_web_link(http://...)

instead of:

   make_web_link("http://...")

--
D'Arcy J.M. Cain
System Administrator, Vex.Net
http://www.Vex.Net/ IM:darcy at Vex.Net VoIP: sip:darcy at Vex.Net



From paul.nospam at rudin.co.uk  Tue Jan  3 15:04:44 2017
From: paul.nospam at rudin.co.uk (Paul Rudin)
Date: Wed, 04 Jan 2017 08:04:44 +1200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I do
References: <4053936668@f38.n261.z1.binkp.net>
Message-ID: <2996724295@f38.n261.z1.binkp.net>

Tim Johnson <tim at akwebsoft.com> writes:

> * Antonio Caminero Garcia <tonycamgar at gmail.com> [170102 20:56]:
>> Guys really thank you for your answers. Basically now I am more
>> emphasizing in learning in depth a tool and get stick to it so I
>> can get a fast workflow. Eventually I will learn Vim and its
>> python developing setup, I know people who have been programming
>> using Vim for almost 20 years and they did not need to change
>> editor (that is really awesome).
>
>  Bye the way, one thing I like about the GUI based vim is that it
>  supports tabs, where emacs does not.

M-x package-install tabbar



From paul.nospam at rudin.co.uk  Tue Jan  3 15:04:44 2017
From: paul.nospam at rudin.co.uk (Paul Rudin)
Date: Wed, 04 Jan 2017 08:04:44 +1200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I do
Message-ID: <1210886351@f38.n261.z1.binkp.net>

Tim Johnson <tim at akwebsoft.com> writes:

> * Antonio Caminero Garcia <tonycamgar at gmail.com> [170102 20:56]:
>> Guys really thank you for your answers. Basically now I am more
>> emphasizing in learning in depth a tool and get stick to it so I
>> can get a fast workflow. Eventually I will learn Vim and its
>> python developing setup, I know people who have been programming
>> using Vim for almost 20 years and they did not need to change
>> editor (that is really awesome).
>
>  Bye the way, one thing I like about the GUI based vim is that it
>  supports tabs, where emacs does not.

M-x package-install tabbar



From python at deborahswanson.net  Tue Jan  3 15:06:43 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 12:06:43 -0800
Subject: Screwing Up looping in Generator
In-Reply-To: <7c38d03e-566c-4d36-9e41-84f913b2e097@googlegroups.com>
Message-ID: <002801d265fc$e7c66ab0$27b23dae@sambora>

Sayth Renshaw wrote, on January 03, 2017 6:54 AM
> 
> Hi
> 
> This is simple, but its getting me confused.
> 
> I have a csv writer that opens a file and loops each line of 
> the file for each file and then closes, writing one file.
> 
> I want to alter the behaviour to be a written file for each 
> input file. I saw a roundrobin example however it failed for 
> me as you cannot get len(generator) to use a while loop on. 
> it exhausts
> 
> should I use the same for again after the with open?
> 
> rootobs in this code is my generator and I am already looping 
> it however 
> def data_attr(roots):
>     """Get the root object and iter items."""
>     for file in rootobs:
>         base = os.path.basename(file.name)
>         write_to = os.path.join("output", 
> os.path.splitext(base)[0] + ".csv")
>         with open(write_to, 'w', newline='') as csvf:
>             race_writer = csv.writer(csvf, delimiter=',')
>             race_writer.writerow(
>                 ["meet_id", "meet_venue", "meet_date", "meet_rail",
>                  ...
>                  # other categories here
>                  ...
>                     "jockeysurname", "jockeyfirstname"])
>             for xml_data in roots:
>                 ...
>                 # parsing code
>                         for noms in race_child:
>                             if noms.tag == 'nomination':
>                                 race_writer.writerow(
>                                     [meet_id, meet_venue, meet_date,
>                                      ...
>                                     #parsing info removed
>                                         noms.get("jockeyfirstname")])
> 
> Cheers
> Sayth

What's the code for your generator? And I don't see where you call
'next'.



From uri at speedy.net  Tue Jan  3 15:07:38 2017
From: uri at speedy.net (Uri Even-Chen)
Date: Tue, 3 Jan 2017 22:07:38 +0200
Subject: pip install -r requirements.txt fails with Python 3.6 on Windows
 10
In-Reply-To: <CAEfz+Ty-NKKfDfw-VrjYbnBHRrbxX0_VFw=DEFZxz6zy08sYVg@mail.gmail.com>
References: <CAMQ2MsFS-YHajpia_Q_s6dses2MAj7zeMir69CcPQ9R6Tr1MvQ@mail.gmail.com>
 <CAEfz+Ty-NKKfDfw-VrjYbnBHRrbxX0_VFw=DEFZxz6zy08sYVg@mail.gmail.com>
Message-ID: <CAMQ2MsH1RiPfta+su1iZyOdJck6sb2rOzWzD3taxqOV6c86Zhg@mail.gmail.com>

Thank you, I'll consider to update our requirements to latest versions of
all packages. Last time I checked in 22th December 2016 and all our
requirements were the latest versions. In the meantime we can keep using
Python 3.5. By the way, Travis CI tests passed with the same requirements
and Python 3.6 (and 3.5 and 3.4). How did it install the requirements
there? Does it depend on the operating system?

I see now that Python 3.6.0 was released on 2016-12-23.

By the way we use Ubuntu 16.04 in production with Python 3.5.2, so it's not
that important to support Python 3.6 right now. What are the reasons to
upgrade Python to 3.6?

Thanks,
Uri.


*Uri Even-Chen*
[image: photo] Phone: +972-54-3995700
Email: uri at speedy.net
Website: http://www.speedysoftware.com/uri/en/
<http://www.facebook.com/urievenchen>  <http://plus.google.com/+urievenchen>
  <http://www.linkedin.com/in/urievenchen>  <http://github.com/urievenchen>
<http://twitter.com/urievenchen>


From python at deborahswanson.net  Tue Jan  3 15:17:01 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 12:17:01 -0800
Subject: Screwing Up looping in Generator
Message-ID: <002d01d265fe$5840b560$27b23dae@sambora>

> Sayth Renshaw wrote, on January 03, 2017 6:54 AM
> > 
> > Hi
> > 
> > This is simple, but its getting me confused.
> > 
> > I have a csv writer that opens a file and loops each line of
> > the file for each file and then closes, writing one file.
> > 
> > I want to alter the behaviour to be a written file for each
> > input file. I saw a roundrobin example however it failed for 
> > me as you cannot get len(generator) to use a while loop on. 
> > it exhausts
> > 
> > should I use the same for again after the with open?
> > 
> > rootobs in this code is my generator and I am already looping
> > it however 
> > def data_attr(roots):
> >     """Get the root object and iter items."""
> >     for file in rootobs:
> >         base = os.path.basename(file.name)
> >         write_to = os.path.join("output", 
> > os.path.splitext(base)[0] + ".csv")
> >         with open(write_to, 'w', newline='') as csvf:
> >             race_writer = csv.writer(csvf, delimiter=',')
> >             race_writer.writerow(
> >                 ["meet_id", "meet_venue", "meet_date", "meet_rail",
> >                  ...
> >                  # other categories here
> >                  ...
> >                     "jockeysurname", "jockeyfirstname"])
> >             for xml_data in roots:
> >                 ...
> >                 # parsing code
> >                         for noms in race_child:
> >                             if noms.tag == 'nomination':
> >                                 race_writer.writerow(
> >                                     [meet_id, meet_venue, meet_date,
> >                                      ...
> >                                     #parsing info removed
> >                                         
> noms.get("jockeyfirstname")])
> > 
> > Cheers
> > Sayth
> 
> What's the code for your generator? And I don't see where you 
> call 'next'.

I think you're expecting 

	for file in rootobs

to get the next yield for you from rootobs, but unless someone corrects
me, I don't think you can expect a 'for' statement to do that. You need
to have a 'next' statement inside your for loop to get the next yield
from the generator.

But I might not understand exactly what you're asking.




From paul.nospam at rudin.co.uk  Tue Jan  3 15:22:02 2017
From: paul.nospam at rudin.co.uk (Paul Rudin)
Date: Wed, 04 Jan 2017 08:22:02 +1200
Subject: Clickable hyperlinks
References: <973176847@f38.n261.z1.binkp.net>
Message-ID: <4043841764@f38.n261.z1.binkp.net>

"Deborah Swanson" <python at deborahswanson.net> writes:

>
> I didn't try printing them before, but I just did. Got:
>
>>>> print([Example](http://www.example.com)
>
> SyntaxError: invalid syntax  (arrow pointing at the colon)
>

With respect, if you typed that at python then it's probably a good idea to 
take a step back and work through the excellent tutorial.

https://docs.python.org/3/tutorial/



From breamoreboy at gmail.com  Tue Jan  3 15:51:06 2017
From: breamoreboy at gmail.com (breamoreboy at gmail.com)
Date: Tue, 3 Jan 2017 12:51:06 -0800 (PST)
Subject: pip install -r requirements.txt fails with Python 3.6 on Windows
 10
In-Reply-To: <mailman.152.1483474101.2395.python-list@python.org>
References: <CAMQ2MsFS-YHajpia_Q_s6dses2MAj7zeMir69CcPQ9R6Tr1MvQ@mail.gmail.com>
 <CAEfz+Ty-NKKfDfw-VrjYbnBHRrbxX0_VFw=DEFZxz6zy08sYVg@mail.gmail.com>
 <CAMQ2MsH1RiPfta+su1iZyOdJck6sb2rOzWzD3taxqOV6c86Zhg@mail.gmail.com>
 <mailman.152.1483474101.2395.python-list@python.org>
Message-ID: <9267d08b-23ac-4173-af90-cd4fa7bd7a28@googlegroups.com>

On Tuesday, January 3, 2017 at 8:08:37 PM UTC, Uri Even-Chen wrote:
> Thank you, I'll consider to update our requirements to latest versions of
> all packages. Last time I checked in 22th December 2016 and all our
> requirements were the latest versions. In the meantime we can keep using
> Python 3.5. By the way, Travis CI tests passed with the same requirements
> and Python 3.6 (and 3.5 and 3.4). How did it install the requirements
> there? Does it depend on the operating system?
> 
> I see now that Python 3.6.0 was released on 2016-12-23.
> 
> By the way we use Ubuntu 16.04 in production with Python 3.5.2, so it's not
> that important to support Python 3.6 right now. What are the reasons to
> upgrade Python to 3.6?
> 
> Thanks,
> Uri.
> 
> 
> *Uri Even-Chen*
> [image: photo] Phone: +972-54-3995700
> Website: http://www.speedysoftware.com/uri/en/
> <http://www.facebook.com/urievenchen>  <http://plus.google.com/+urievenchen>
>   <http://www.linkedin.com/in/urievenchen>  <http://github.com/urievenchen>
> <http://twitter.com/urievenchen>


Go here http://www.lfd.uci.edu/~gohlke/pythonlibs/#pillow to get what you need.

In all my years of downloading from this site I've never, ever had a problem.

Kindest regards.

Mark Lawrence.


From python at deborahswanson.net  Tue Jan  3 15:53:01 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 12:53:01 -0800
Subject: Screwing Up looping in Generator
In-Reply-To: <002d01d265fe$5840b560$27b23dae@sambora>
Message-ID: <003501d26603$5fe3def0$27b23dae@sambora>

> > Sayth Renshaw wrote, on January 03, 2017 6:54 AM
> > > 
> > > Hi
> > > 
> > > This is simple, but its getting me confused.
> > > 
> > > I have a csv writer that opens a file and loops each line of the 
> > > file for each file and then closes, writing one file.
> > > 
> > > I want to alter the behaviour to be a written file for each input 
> > > file. I saw a roundrobin example however it failed for me as you 
> > > cannot get len(generator) to use a while loop on. it exhausts
> > > 
> > > should I use the same for again after the with open?
> > > 
> > > rootobs in this code is my generator and I am already looping it 
> > > however def data_attr(roots):
> > >     """Get the root object and iter items."""
> > >     for file in rootobs:
> > >         base = os.path.basename(file.name)
> > >         write_to = os.path.join("output", 
> > > os.path.splitext(base)[0] + ".csv")
> > >         with open(write_to, 'w', newline='') as csvf:
> > >             race_writer = csv.writer(csvf, delimiter=',')
> > >             race_writer.writerow(
> > >                 ["meet_id", "meet_venue", "meet_date", 
> "meet_rail",
> > >                  ...
> > >                  # other categories here
> > >                  ...
> > >                     "jockeysurname", "jockeyfirstname"])
> > >             for xml_data in roots:
> > >                 ...
> > >                 # parsing code
> > >                         for noms in race_child:
> > >                             if noms.tag == 'nomination':
> > >                                 race_writer.writerow(
> > >                                     [meet_id, meet_venue, 
> meet_date,
> > >                                      ...
> > >                                     #parsing info removed
> > >                                         
> > noms.get("jockeyfirstname")])
> > > 
> > > Cheers
> > > Sayth
> > 
> > What's the code for your generator? And I don't see where you
> > call 'next'.
> 
> I think you're expecting 
> 
> 	for file in rootobs
> 
> to get the next yield for you from rootobs, but unless 
> someone corrects me, I don't think you can expect a 'for' 
> statement to do that. You need to have a 'next' statement 
> inside your for loop to get the next yield from the generator.
> 
> But I might not understand exactly what you're asking.

You probably want something like :

for f in rootobs:
    file = next
    base = os.path.basename(file.name) 
       .
       .	
       .
      (etc)

Notice I changed your iterating variable name to 'f', so you can use
'file' throughout your code after you get the next one from rootobs.

As written, you'll get a StopIteration exception when rootobs runs out
of files, which you can catch with a try/except. Or you can just let the
code end there if you're done.



From jeanpierreda at gmail.com  Tue Jan  3 15:57:08 2017
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Tue, 3 Jan 2017 12:57:08 -0800
Subject: Clickable hyperlinks
In-Reply-To: <001e01d265fa$0c639d50$27b23dae@sambora>
References: <001501d264e4$32189a80$27b23dae@sambora>
 <001e01d265fa$0c639d50$27b23dae@sambora>
Message-ID: <CABicbJLxh3qSAb5J9fTadWVA1PY-6bopY45jWgL9XX_k+oVY3w@mail.gmail.com>

Sadly, no. :(  Consoles (and stdout) are just text, not hypertext. The way
to make an URL clickable is to use a terminal that makes URLs clickable,
and print the URL:

print("%s: %s" % (description, url))

-- Devin

On Tue, Jan 3, 2017 at 11:46 AM, Deborah Swanson <python at deborahswanson.net>
wrote:

> Excel has a formula:
>
> =HYPERLINK(url,description)
>
> that will put a clickable link into a cell.
>
> Does python have an equivalent function? Probably the most common use
> for it would be output to the console, similar to a print statement, but
> clickable.
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>


From darcy at vex.net  Tue Jan  3 15:58:02 2017
From: darcy at vex.net (D'Arcy Cain)
Date: Wed, 04 Jan 2017 08:58:02 +1200
Subject: Clickable hyperlinks
Message-ID: <59259788@f38.n261.z1.binkp.net>

On 2017-01-04 08:44 AM, Rodrigo Bistolfi wrote:
> 2017-01-04 7:39 GMT-03:00 Steve D'Aprano <steve+python at pearwood.info>:
>> Aside: you've actually raised a fascinating question. I wonder whether
>> there
>> are any programming languages that understand URLs as native data types, so
>> that *source code* starting with http:// etc is understood in the same way
>> that source code starting with [ is seen as a list or { as a dict?
>
> Some Smalltalk implementations have something that comes close:
>
> st> 'https://python.org' asUrl retrieveContents

But notice that even here the URL has to be defined as a string.  To be a first 
class object you would need to do something like this:

   url = https://python.org/

The only time you would see that is in config files and languages like shell 
where everything is a string so no quotes necessary.  They are implied.

> `asUrl` would be a string method returning a URL instance, which also has a
> convenient method `retrieveContents` wrapping an http client. Not hard to
> do with Python, I think this could be an interesting exercise for a learner.

Sure but the issue is, what to do with it.  In any case, it's still just a 
wrapper around various string methods.  You still need to give the class a 
string to create the object.

--
D'Arcy J.M. Cain
System Administrator, Vex.Net
http://www.Vex.Net/ IM:darcy at Vex.Net VoIP: sip:darcy at Vex.Net



From python at deborahswanson.net  Tue Jan  3 16:19:17 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 13:19:17 -0800
Subject: Screwing Up looping in Generator
Message-ID: <003c01d26607$0adbd8f0$27b23dae@sambora>


> > > Sayth Renshaw wrote, on January 03, 2017 6:54 AM
> > > > 
> > > > Hi
> > > > 
> > > > This is simple, but its getting me confused.
> > > > 
> > > > I have a csv writer that opens a file and loops each line of the
> > > > file for each file and then closes, writing one file.
> > > > 
> > > > I want to alter the behaviour to be a written file for 
> each input
> > > > file. I saw a roundrobin example however it failed for 
> me as you 
> > > > cannot get len(generator) to use a while loop on. it exhausts
> > > > 
> > > > should I use the same for again after the with open?
> > > > 
> > > > rootobs in this code is my generator and I am already looping it
> > > > however def data_attr(roots):
> > > >     """Get the root object and iter items."""
> > > >     for file in rootobs:
> > > >         base = os.path.basename(file.name)
> > > >         write_to = os.path.join("output", 
> > > > os.path.splitext(base)[0] + ".csv")
> > > >         with open(write_to, 'w', newline='') as csvf:
> > > >             race_writer = csv.writer(csvf, delimiter=',')
> > > >             race_writer.writerow(
> > > >                 ["meet_id", "meet_venue", "meet_date", 
> > "meet_rail",
> > > >                  ...
> > > >                  # other categories here
> > > >                  ...
> > > >                     "jockeysurname", "jockeyfirstname"])
> > > >             for xml_data in roots:
> > > >                 ...
> > > >                 # parsing code
> > > >                         for noms in race_child:
> > > >                             if noms.tag == 'nomination':
> > > >                                 race_writer.writerow(
> > > >                                     [meet_id, meet_venue,
> > meet_date,
> > > >                                      ...
> > > >                                     #parsing info removed
> > > >                                         
> > > noms.get("jockeyfirstname")])
> > > > 
> > > > Cheers
> > > > Sayth
> > > 
> > > What's the code for your generator? And I don't see where 
> you call 
> > > 'next'.
> > 
> > I think you're expecting
> > 
> > 	for file in rootobs
> > 
> > to get the next yield for you from rootobs, but unless
> > someone corrects me, I don't think you can expect a 'for' 
> > statement to do that. You need to have a 'next' statement 
> > inside your for loop to get the next yield from the generator.
> > 
> > But I might not understand exactly what you're asking.
> 
> You probably want something like :
> 
> for f in rootobs:
>     file = next
>     base = os.path.basename(file.name) 
>        .
>        .	
>        .
>       (etc)
> 
> Notice I changed your iterating variable name to 'f', so you 
> can use 'file' throughout your code after you get the next 
> one from rootobs.
> 
> As written, you'll get a StopIteration exception when rootobs 
> runs out of files, which you can catch with a try/except. Or 
> you can just let the code end there if you're done.

Well rats, I'm embarrassed. It's been awhile since I've used a generator
and I forgot that you have to create the generator object first and use
it to call the next function. And I really don't think you can use a
generator as your range in a for loop. So I'd use a 'while True', and
break out of the loop when you hit the StopIteration exception:

files = rootobs()

while True:
  try: 
    file = files.next()
  except StopIteration:
    break

    base = os.path.basename(file.name) 
       .
       .	
       .
      (etc)

(Now I'm just going to shut up, until somebody else says something.)



From rosuav at gmail.com  Tue Jan  3 16:30:48 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 04 Jan 2017 09:30:48 +1200
Subject: Screwing Up looping in Generator
Message-ID: <655490577@f38.n261.z1.binkp.net>

On Wed, Jan 4, 2017 at 8:19 AM, Deborah Swanson
<python at deborahswanson.net> wrote:
> while True:
>   try:
>     file = files.next()
>   except StopIteration:
>     break

Small side point: Try to avoid calling a generator object's .next() method 
directly. Normally, when you _do_ want to do this, you should be calling 
next(files). In Python 3, the magic method is now __next__(), which emphasizes 
that it's for defining, not calling.

As others have pointed out, though, the for loop is the correct tool for this 
job.

ChrisA



From python at deborahswanson.net  Tue Jan  3 16:34:49 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 13:34:49 -0800
Subject: Clickable hyperlinks
In-Reply-To: <CABicbJLxh3qSAb5J9fTadWVA1PY-6bopY45jWgL9XX_k+oVY3w@mail.gmail.com>
Message-ID: <003f01d26609$36cd78e0$27b23dae@sambora>

Devin Jeanpierre wrote, on January 03, 2017 12:57 PM

>Sadly, no. :(  Consoles (and stdout) are just text, not hypertext. The
way to 
>make an URL clickable is to use a terminal that makes URLs clickable,
and  
>print the URL:
>
>
>print("%s: %s" % (description, url))
>
>
>
>
>-- Devin

I'm sorry, I should have said a GUI console because I wouldn't expect a
text-based console to produce clickable links. But it appears that a
simple GUI console can't do it either. I have 3 GUI consoles and in all
3, when I ask:

print("%s: %s" % ("python.org list",
"https://mail.python.org/mailman/listinfo/python-list"))

I get:
python.org list: https://mail.python.org/mailman/listinfo/python-list

(Outlook made the url clickable here, the python GUI consoles just
output plain text.)

Pretty clearly the output is plain text because your format parameters
are %s. Maybe the trick, if there is one, is in a format parameter for
urls.



On Tue, Jan 3, 2017 at 11:46 AM, Deborah Swanson
<python at deborahswanson.net> wrote:

Excel has a formula:

=HYPERLINK(url,description)

that will put a clickable link into a cell.

Does python have an equivalent function? Probably the most common use
for it would be output to the console, similar to a print statement, but
clickable.

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



From D.Strohl at F5.com  Tue Jan  3 16:34:57 2017
From: D.Strohl at F5.com (Dan Strohl)
Date: Tue, 3 Jan 2017 21:34:57 +0000
Subject: Clickable hyperlinks
In-Reply-To: <CABicbJLxh3qSAb5J9fTadWVA1PY-6bopY45jWgL9XX_k+oVY3w@mail.gmail.com>
References: <001501d264e4$32189a80$27b23dae@sambora>
 <001e01d265fa$0c639d50$27b23dae@sambora>
 <CABicbJLxh3qSAb5J9fTadWVA1PY-6bopY45jWgL9XX_k+oVY3w@mail.gmail.com>
Message-ID: <70378eddf25145b7b7d58783cdb9234b@F5.com>

The best bet (unless you know that you are outputting to a specific place, like html or excel) is to always include the "https://" or "http://" since most of the consoles / terminals that support clickable links are parsing them based on "seeing" the initial "http://".  If your output just looks like "mysite.com/coolpage.html", many systems will simply ignore them.

At one point I had made a class that you could pass the link to, and then you could request different output based on your needs... so basically something like:

>> url = url_class("mysite.com/coolpage.html")
>> print(url) 
"http://mysite.com/coolpage.html")
>> print(url.plain)
"mysite.com/coolpage.html"
>> print(url.html('My Site"))
'<a href="http://mysite.com/coolpage.html">My Site</a>'

(or whatever... I think I actually just sub-classed url.parse or something)




-----Original Message-----
From: Python-list [mailto:python-list-bounces+d.strohl=f5.com at python.org] On Behalf Of Devin Jeanpierre
Sent: Tuesday, January 03, 2017 12:57 PM
To: python at deborahswanson.net
Cc: comp.lang.python <python-list at python.org>
Subject: Re: Clickable hyperlinks

Sadly, no. :(  Consoles (and stdout) are just text, not hypertext. The way to make an URL clickable is to use a terminal that makes URLs clickable, and print the URL:

print("%s: %s" % (description, url))

-- Devin

On Tue, Jan 3, 2017 at 11:46 AM, Deborah Swanson <python at deborahswanson.net>
wrote:

> Excel has a formula:
>
> =HYPERLINK(url,description)
>
> that will put a clickable link into a cell.
>
> Does python have an equivalent function? Probably the most common use 
> for it would be output to the console, similar to a print statement, 
> but clickable.
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>
--
https://mail.python.org/mailman/listinfo/python-list


From rosuav at gmail.com  Tue Jan  3 16:38:50 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 04 Jan 2017 09:38:50 +1200
Subject: How Best to Coerce Python Objects to Integers?
Message-ID: <547107055@f38.n261.z1.binkp.net>

On Wed, Jan 4, 2017 at 8:41 AM,  <breamoreboy at gmail.com> wrote:
> Hi all, I'd suggest that this http://blog.pyspoken.com/2017/01/02/how-best-to
-coerce-python-objects-to-integers/ is not one of the greatest articles ever
written about Python exception handling.  Other opinions are welcome.
>

"""
So there you have it. I? ?m happy with this function. It feels bulletproof. It 
contains a naked except, but that only covers one simple line of code that? ?s 
unlikely to hide anything nasty. """

Yep! It's perfect. He has successfully made a function that won't leak any 
exceptions. Congratulations!

The novice believes that the first priority is to stop the program from 
crashing. The expert understands that crashing (especially with an exception, 
but even a segfault) is actually very helpful and useful.

I love the logic that a bare 'except' is okay as long as it's only covering one 
single line of code. There's almost enough truth in that to be meaningful, 
while still completely missing the point that a NameError is almost certainly a 
bug no matter where it crops up.

ChrisA



From wrw at mac.com  Tue Jan  3 16:41:24 2017
From: wrw at mac.com (William Ray Wing)
Date: Wed, 04 Jan 2017 09:41:24 +1200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I do
Message-ID: <2588366108@f38.n261.z1.binkp.net>


> On Jan 4, 2017, at 1:54 AM, Antonio Caminero Garcia <tonycamgar at gmail.com>
wrote:
>
> On Tuesday, January 3, 2017 at 4:12:34 PM UTC-8, Dietmar Schwertberger wrote:
>> On 02.01.2017 12:38, Antonio Caminero Garcia wrote:
>> You did not try Wing IDE? It looks less like a spacecraft. Maybe you
>> like it.
>> Maybe the difference is that Wing is from Python people while the ones
>> you listed are from Java people.
>
> That sounds interesting. By the look of it I think I am going to give it a
try.
>
>

[byte]


> I want editor with those IDE capabilities and git integration, with
optionally  cool stuff as for example remote debugging.

I use Wing, and I think you will like it.  It *is* pythonic, and for what it is 
worth, offers remote debugging as one of its more recently added features.

-Bill



From breamoreboy at gmail.com  Tue Jan  3 16:41:44 2017
From: breamoreboy at gmail.com (breamoreboy at gmail.com)
Date: Tue, 3 Jan 2017 13:41:44 -0800 (PST)
Subject: How Best to Coerce Python Objects to Integers?
Message-ID: <3d35c052-a4c2-44f9-b294-cb1a77d77477@googlegroups.com>

Hi all, I'd suggest that this http://blog.pyspoken.com/2017/01/02/how-best-to-coerce-python-objects-to-integers/ is not one of the greatest articles ever written about Python exception handling.  Other opinions are welcome.

Kindest regards.

Mark Lawrence.


From random832 at fastmail.com  Tue Jan  3 16:43:04 2017
From: random832 at fastmail.com (Random832)
Date: Wed, 04 Jan 2017 09:43:04 +1200
Subject: Simulating int arithmetic with wrap-around
Message-ID: <1046720962@f38.n261.z1.binkp.net>

On Fri, Dec 30, 2016, at 09:47, Steve D'Aprano wrote:
> Again, assume both operands are in range for an N-bit signed integer.
> What's
> a good way to efficiently, or at least not too inefficiently, do the
> calculations in Python?

I'd do something like:

bit_mask = (1 << bits) - 1 # 0xFFFF sign_bit = 1 << (bits - 1) # 0x8000 
sign_ext = ~bit_mask # ...FFFFF0000

def signed(value):
    if value & sign_bit:
        return value | sign_ext
    else:
        return value & bit_mask

def unsigned(value):
    return value & bit_mask

And also avoid doing it on intermediate steps where it can be shown to not 
affect the result or allow the value to grow too large.



From m at funkyhat.org  Tue Jan  3 16:46:57 2017
From: m at funkyhat.org (Matt Wheeler)
Date: Tue, 03 Jan 2017 21:46:57 +0000
Subject: Screwing Up looping in Generator
In-Reply-To: <002d01d265fe$5840b560$27b23dae@sambora>
References: <002d01d265fe$5840b560$27b23dae@sambora>
Message-ID: <CAG93HwFz8LNGy+7UEE1x+GkvSX8D0GA_OJpg77_nkfeuwGkK2w@mail.gmail.com>

On Tue, 3 Jan 2017 at 20:17 Deborah Swanson <python at deborahswanson.net>
wrote:

> > What's the code for your generator? And I don't see where you
> > call 'next'.
>
> I think you're expecting
>
>         for file in rootobs
>
> to get the next yield for you from rootobs, but unless someone corrects
> me, I don't think you can expect a 'for' statement to do that. You need
> to have a 'next' statement inside your for loop to get the next yield
> from the generator.
>

Yes, you absolutely can expect a for statement to do that. It will accept
any iterable as its `y`.

`for x in y: stuff(x)` is effectively syntactic sugar for:

iterator = iter(y)
while True:
    try:
        x = next(iterator)
    except(StopIteration):
        break
    stuff(x)

Manually calling `next()` inside a `while True:` is quite an unusual thing
to do.

range() is not part of the for syntax at all, it's completely separate, it
simply returns an iterator which the for loop can use, like any other.
-- 

--
Matt Wheeler
http://funkyh.at


From rosuav at gmail.com  Tue Jan  3 16:47:16 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 04 Jan 2017 09:47:16 +1200
Subject: How Best to Coerce Python Objects to Integers?
Message-ID: <4059713349@f38.n261.z1.binkp.net>

On Wed, Jan 4, 2017 at 9:42 AM, Ethan Furman <ethan at stoneleaf.us> wrote:
> Aside from calling "except Exception" a "naked except"

If you read the comments, you'll see that he originally had an actual bare 
except clause, but then improved the code somewhat in response to a 
recommendation that SystemExit etc not be caught.

ChrisA



From D.Strohl at F5.com  Tue Jan  3 16:47:58 2017
From: D.Strohl at F5.com (Dan Strohl)
Date: Tue, 3 Jan 2017 21:47:58 +0000
Subject: Clickable hyperlinks
In-Reply-To: <003f01d26609$36cd78e0$27b23dae@sambora>
References: <CABicbJLxh3qSAb5J9fTadWVA1PY-6bopY45jWgL9XX_k+oVY3w@mail.gmail.com>
 <003f01d26609$36cd78e0$27b23dae@sambora>
Message-ID: <93636ab19e434c029e2cdf1f14e8809a@F5.com>

Keeping mind how this all works... 

Python is providing the data, the console/terminal/app handles how that data is displayed.   There is no specification for text output to be hyperlinked (that I know about at least), so while some apps may handle specific coding to tell them that "this text should be a hyperlink", most will either parse the text looking for hyper-linkable string, or more commonly, just output the text as text.

If you control the app that is displaying info to the user (such as using QT or another GUI tool), or generating html yourself, you can control if a text string is a hyperlink or not, and what to do with the hyperlink when clicked.  

So, if you want clickable links, you would need to find a console/terminal that supported them.

Some references:
https://opensource.com/life/15/11/top-open-source-terminal-emulators  (see Gnome)
http://unix.stackexchange.com/questions/63417/is-there-a-terminal-app-that-allows-filenames-to-be-clickable
http://superuser.com/questions/654116/configure-os-x-terminal-to-detect-urls-and-make-them-clickable
http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/url-launching.html


-----Original Message-----
From: Python-list [mailto:python-list-bounces+d.strohl=f5.com at python.org] On Behalf Of Deborah Swanson
Sent: Tuesday, January 03, 2017 1:35 PM
To: 'Devin Jeanpierre' <jeanpierreda at gmail.com>
Cc: 'comp.lang.python' <python-list at python.org>
Subject: RE: Re: Clickable hyperlinks

Devin Jeanpierre wrote, on January 03, 2017 12:57 PM

>Sadly, no. :(  Consoles (and stdout) are just text, not hypertext. The
way to 
>make an URL clickable is to use a terminal that makes URLs clickable,
and  
>print the URL:
>
>
>print("%s: %s" % (description, url))
>
>
>
>
>-- Devin

I'm sorry, I should have said a GUI console because I wouldn't expect a text-based console to produce clickable links. But it appears that a simple GUI console can't do it either. I have 3 GUI consoles and in all 3, when I ask:

print("%s: %s" % ("python.org list",
"https://mail.python.org/mailman/listinfo/python-list"))

I get:
python.org list: https://mail.python.org/mailman/listinfo/python-list

(Outlook made the url clickable here, the python GUI consoles just output plain text.)

Pretty clearly the output is plain text because your format parameters are %s. Maybe the trick, if there is one, is in a format parameter for urls.



On Tue, Jan 3, 2017 at 11:46 AM, Deborah Swanson <python at deborahswanson.net> wrote:

Excel has a formula:

=HYPERLINK(url,description)

that will put a clickable link into a cell.

Does python have an equivalent function? Probably the most common use for it would be output to the console, similar to a print statement, but clickable.

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

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


From tjreedy at udel.edu  Tue Jan  3 16:48:48 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Tue, 3 Jan 2017 16:48:48 -0500
Subject: pip install -r requirements.txt fails with Python 3.6 on Windows
 10
In-Reply-To: <CAMQ2MsH1RiPfta+su1iZyOdJck6sb2rOzWzD3taxqOV6c86Zhg@mail.gmail.com>
References: <CAMQ2MsFS-YHajpia_Q_s6dses2MAj7zeMir69CcPQ9R6Tr1MvQ@mail.gmail.com>
 <CAEfz+Ty-NKKfDfw-VrjYbnBHRrbxX0_VFw=DEFZxz6zy08sYVg@mail.gmail.com>
 <CAMQ2MsH1RiPfta+su1iZyOdJck6sb2rOzWzD3taxqOV6c86Zhg@mail.gmail.com>
Message-ID: <o4h67s$4i3$1@blaine.gmane.org>

On 1/3/2017 3:07 PM, Uri Even-Chen wrote:
> What are the reasons to upgrade Python to 3.6?

The same as for any new version:
New features  -- see What's New in 3.6.
New bug fixes.
New performance improvements.

Reasons against:
The effort to make sure all dependencies are available for 3.6*
Possible regressions.

* For Windows, any of the 381 wheels available from 
http://www.lfd.uci.edu/~gohlke/pythonlibs/
should be available in 3.6 versions (unless there was a major problem in 
recompiling).

-- 
Terry Jan Reedy



From m at funkyhat.org  Tue Jan  3 16:49:22 2017
From: m at funkyhat.org (Matt Wheeler)
Date: Tue, 03 Jan 2017 21:49:22 +0000
Subject: Screwing Up looping in Generator
In-Reply-To: <CAG93HwFz8LNGy+7UEE1x+GkvSX8D0GA_OJpg77_nkfeuwGkK2w@mail.gmail.com>
References: <002d01d265fe$5840b560$27b23dae@sambora>
 <CAG93HwFz8LNGy+7UEE1x+GkvSX8D0GA_OJpg77_nkfeuwGkK2w@mail.gmail.com>
Message-ID: <CAG93HwFdaeLPB1eyXK9+_=WQ7k=krzfi8sh3wKVSrT1sa01XMg@mail.gmail.com>

On Tue, 3 Jan 2017 at 21:46 Matt Wheeler <m at funkyhat.org> wrote:

> range() is not part of the for syntax at all, it's completely separate, it
> simply returns an iterator which the for loop can use, like any other.
>

*iterable
-- 

--
Matt Wheeler
http://funkyh.at


From rgaddi at highlandtechnology.invalid  Tue Jan  3 16:50:26 2017
From: rgaddi at highlandtechnology.invalid (Rob Gaddi)
Date: Wed, 04 Jan 2017 09:50:26 +1200
Subject: Simulating int arithmetic with wrap-around
References: <1195249011@f38.n261.z1.binkp.net>
Message-ID: <3975862436@f38.n261.z1.binkp.net>

On 01/03/2017 10:00 PM, Gregory Ewing wrote:
> Paul Rubin wrote:
>> My first thought is towards the struct module, especially if you want to
>> handle a bunch of such integers at the same time.  Or maybe the array
>> module or some combination.
>
> Or possibly numpy.
>

Agreed.  If you had to do a lot of calculations on arbitrary sized 
signed/unsigned ints, figuring how to parallelize them into numpy arrays would 
save you a ton of time.

--
Rob Gaddi, Highland Technology -- www.highlandtechnology.com Email address 
domain is currently out of order.  See above to fix.



From tjreedy at udel.edu  Tue Jan  3 16:57:52 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Tue, 3 Jan 2017 16:57:52 -0500
Subject: Screwing Up looping in Generator
In-Reply-To: <003501d26603$5fe3def0$27b23dae@sambora>
References: <002d01d265fe$5840b560$27b23dae@sambora>
 <003501d26603$5fe3def0$27b23dae@sambora>
Message-ID: <o4h6ot$7vd$1@blaine.gmane.org>

On 1/3/2017 3:53 PM, Deborah Swanson wrote:

>> I think you're expecting
>>
>> 	for file in rootobs
>>
>> to get the next yield for you from rootobs, but unless
>> someone corrects me, I don't think you can expect a 'for'
>> statement to do that. You need to have a 'next' statement
>> inside your for loop to get the next yield from the generator.

As I read this, out of context, it is wrong.  It it very unusual to call 
next on the current iterator (here next(rootobs)), inside a for loop.

> You probably want something like :
>
> for f in rootobs:
>     file = next

This is definitely wrong, as it makes 'find' an alias for the next() 
function.

>     base = os.path.basename(file.name)

and file.name will be an AttributeError.

---
If one wants to iterate through files and lines within files, which I 
believe I saw in this thread, one should have a for loop within a for loop.

-- 
Terry Jan Reedy



From python at deborahswanson.net  Tue Jan  3 17:14:50 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 14:14:50 -0800
Subject: Screwing Up looping in Generator
In-Reply-To: <o4h6ot$7vd$1@blaine.gmane.org>
Message-ID: <006101d2660e$cdca05b0$27b23dae@sambora>

Terry Reedy
> 
> On 1/3/2017 3:53 PM, Deborah Swanson wrote:
> 
> >> I think you're expecting
> >>
> >> 	for file in rootobs
> >>
> >> to get the next yield for you from rootobs, but unless someone 
> >> corrects me, I don't think you can expect a 'for' statement to do 
> >> that. You need to have a 'next' statement inside your for 
> loop to get 
> >> the next yield from the generator.
> 
> As I read this, out of context, it is wrong.  It it very 
> unusual to call 
> next on the current iterator (here next(rootobs)), inside a for loop.
> 
> > You probably want something like :
> >
> > for f in rootobs:
> >     file = next
> 
> This is definitely wrong, as it makes 'find' an alias for the next() 
> function.
> 
> >     base = os.path.basename(file.name)
> 
> and file.name will be an AttributeError.
> 
> ---
> If one wants to iterate through files and lines within files, which I 
> believe I saw in this thread, one should have a for loop 
> within a for loop.
> 
> -- 
> Terry Jan Reedy

Yes, my first attempts were screwups. I didn't remember generator usage
correctly, but I believe my last answer was correct:

...you have to create the generator object first and use it to call the
next function. And I really don't think you can use a generator as your
range in a for loop. So I'd use a 'while True', and break out of the
loop when you hit the StopIteration exception:

files = rootobs()

while True:
  try: 
    file = files.next()
  except StopIteration:
    break

    base = os.path.basename(file.name) 
       .
       .	
       .
      (etc)



From maillist at schwertberger.de  Tue Jan  3 17:20:37 2017
From: maillist at schwertberger.de (Dietmar Schwertberger)
Date: Tue, 3 Jan 2017 23:20:37 +0100
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
Message-ID: <64837604-9f3a-806c-d631-fcc352738952@schwertberger.de>

On 02.01.2017 12:38, Antonio Caminero Garcia wrote:
> The thing with the from-the-scratch full featured IDEs (Eclipse, IntelliJ, Pycharm) is that they look like a space craft dashboard and that unwarranted resources consumption and the unnecessary icons.
You did not try Wing IDE? It looks less like a spacecraft. Maybe you 
like it.
Maybe the difference is that Wing is from Python people while the ones 
you listed are from Java people.
For something completely different (microcontroller programming in C) I 
just switched to a Eclipse derived IDE and I don't like it too much as 
the tool does not focus on the problem scope.

 From your posts I'm not sure whether you want an editor or an IDE, 
where for me the main difference is the debugger and code completion.
I would not want to miss the IDE features any more, even though in my 
first 15 years of Python I thought that a debugger is optional with 
Python ...

Regards,

Dietmar



From python.list at tim.thechases.com  Tue Jan  3 17:26:16 2017
From: python.list at tim.thechases.com (Tim Chase)
Date: Tue, 3 Jan 2017 16:26:16 -0600
Subject: Clickable hyperlinks
In-Reply-To: <001e01d265fa$0c639d50$27b23dae@sambora>
References: <001501d264e4$32189a80$27b23dae@sambora>
 <001e01d265fa$0c639d50$27b23dae@sambora>
Message-ID: <20170103162616.7761ffcc@bigbox.christie.dr>

On 2017-01-03 11:46, Deborah Swanson wrote:
> Excel has a formula:
> 
> =HYPERLINK(url,description)
> 
> that will put a clickable link into a cell.
> 
> Does python have an equivalent function? Probably the most common
> use for it would be output to the console, similar to a print
> statement, but clickable.

Depends on what you're outputting.  In your context, you're creating
content (and metadata) for a cell in an Excel workbook.

If that's the case you might have to use something like the xlwt
module to create an Excel-style worksheet and adjust the properties
of the cell to include the hyperlink property.

Or you can write out a .csv file with a hyperlink in a cell, which I
believe Excel can interpret as a hyperlink.

Or write an HTML document with the corresponding HTML <a> tag in it.

Or you can just print it to stdout as normal as some terminals detect
them and auto-linkify them.

But you have to specify where you want this link to appear to know
how to solve the problem.

-tkc





From rosuav at gmail.com  Tue Jan  3 17:30:48 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 4 Jan 2017 09:30:48 +1100
Subject: Screwing Up looping in Generator
In-Reply-To: <003c01d26607$0adbd8f0$27b23dae@sambora>
References: <003c01d26607$0adbd8f0$27b23dae@sambora>
Message-ID: <CAPTjJmrzc1eCZyQKFCWVTkaL0a_JMz37+T5EjZv=Vx80Crj=SA@mail.gmail.com>

On Wed, Jan 4, 2017 at 8:19 AM, Deborah Swanson
<python at deborahswanson.net> wrote:
> while True:
>   try:
>     file = files.next()
>   except StopIteration:
>     break

Small side point: Try to avoid calling a generator object's .next()
method directly. Normally, when you _do_ want to do this, you should
be calling next(files). In Python 3, the magic method is now
__next__(), which emphasizes that it's for defining, not calling.

As others have pointed out, though, the for loop is the correct tool
for this job.

ChrisA


From rosuav at gmail.com  Tue Jan  3 17:34:58 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 04 Jan 2017 10:34:58 +1200
Subject: Screwing Up looping in Generator
Message-ID: <2629345252@f38.n261.z1.binkp.net>

On Wed, Jan 4, 2017 at 10:05 AM, Deborah Swanson
<python at deborahswanson.net> wrote:
> Ok, I learned how to use generators in Python 2.7.8, which may be
> different from Python 3 for generators. But I learned from MIT's online
> introduction to python course, and they certainly seem to know python
> well. So what is the correct way to call the generator's next yield in
> Python 3? We only learned to use the next function. If you don't use the
> next function, what do you use?

The built-in next function, not the next method.

# don't do this
gen.next()

# do this
next(gen)

ChrisA



From rosuav at gmail.com  Tue Jan  3 17:38:50 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 4 Jan 2017 09:38:50 +1100
Subject: How Best to Coerce Python Objects to Integers?
In-Reply-To: <3d35c052-a4c2-44f9-b294-cb1a77d77477@googlegroups.com>
References: <3d35c052-a4c2-44f9-b294-cb1a77d77477@googlegroups.com>
Message-ID: <CAPTjJmoyXchb2UG+jLJJs83xkJhc-F2o6=J3wYBXYaYK4NUrRg@mail.gmail.com>

On Wed, Jan 4, 2017 at 8:41 AM,  <breamoreboy at gmail.com> wrote:
> Hi all, I'd suggest that this http://blog.pyspoken.com/2017/01/02/how-best-to-coerce-python-objects-to-integers/ is not one of the greatest articles ever written about Python exception handling.  Other opinions are welcome.
>

"""
So there you have it. I?m happy with this function. It feels
bulletproof. It contains a naked except, but that only covers one
simple line of code that?s unlikely to hide anything nasty.
"""

Yep! It's perfect. He has successfully made a function that won't leak
any exceptions. Congratulations!

The novice believes that the first priority is to stop the program
from crashing. The expert understands that crashing (especially with
an exception, but even a segfault) is actually very helpful and
useful.

I love the logic that a bare 'except' is okay as long as it's only
covering one single line of code. There's almost enough truth in that
to be meaningful, while still completely missing the point that a
NameError is almost certainly a bug no matter where it crops up.

ChrisA


From steve+python at pearwood.info  Tue Jan  3 17:39:20 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 10:39:20 +1200
Subject: How Best to Coerce Python Objects to Integers?
References: <4059713349@f38.n261.z1.binkp.net>
Message-ID: <1336731314@f38.n261.z1.binkp.net>

On Wed, 4 Jan 2017 09:47 am, Chris Angelico wrote:

> On Wed, Jan 4, 2017 at 9:42 AM, Ethan Furman <ethan at stoneleaf.us> wrote:
>> Aside from calling "except Exception" a "naked except"
>
> If you read the comments, you'll see that he originally had an actual
> bare except clause, but then improved the code somewhat in response to
> a recommendation that SystemExit etc not be caught.

But why? That makes no sense. If his intention is to return None on failure, no 
matter what happens, then he *should* catch SystemExit. Otherwise:

class Unint:
    def __int__(self):
        raise SystemExit

int_or_else(Unint)


will exit instead of returning None. Surely that's not what he wants, given 
that he wants to cover up other programming errors like NameError and 
TypeError?

The problem here is not so much the use of try...except but the *intention* 
that "Anything whatsoever should be coerced to int". If you have something 
like:

left_margin = int_or_else(ftp_server)

that's surely a programming error that needs fixing, rather than something that 
should just return a default value.



--
Steve
? ?Cheer up,? ? they said, ? ?things could be worse.? ? So I cheered up, and
sure
enough, things got worse.



From ethan at stoneleaf.us  Tue Jan  3 17:42:52 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 03 Jan 2017 14:42:52 -0800
Subject: How Best to Coerce Python Objects to Integers?
In-Reply-To: <3d35c052-a4c2-44f9-b294-cb1a77d77477@googlegroups.com>
References: <3d35c052-a4c2-44f9-b294-cb1a77d77477@googlegroups.com>
Message-ID: <586C28EC.8010607@stoneleaf.us>

On 01/03/2017 01:41 PM, breamoreboy at gmail.com wrote:

> Hi all, I'd suggest that this [1] is not one of the greatest articles
>  ever written about Python exception handling.  Other opinions are welcome.

Aside from calling "except Exception" a "naked except" I think it's decent.  He walks through the problem, explains the rationale, and only has one line of code guarded by the except clause.

--
~Ethan~

[1] http://blog.pyspoken.com/2017/01/02/how-best-to-coerce-python-objects-to-integers/


From rbistolfi at gmail.com  Tue Jan  3 17:44:34 2017
From: rbistolfi at gmail.com (Rodrigo Bistolfi)
Date: Wed, 04 Jan 2017 10:44:34 +1200
Subject: Clickable hyperlinks
Message-ID: <1325525650@f38.n261.z1.binkp.net>

2017-01-04 7:39 GMT-03:00 Steve D'Aprano <steve+python at pearwood.info>:

> On Wed, 4 Jan 2017 08:32 pm, Deborah Swanson wrote:
>
> Aside: you've actually raised a fascinating question. I wonder whether
> there
> are any programming languages that understand URLs as native data types, so
> that *source code* starting with http:// etc is understood in the same way
> that source code starting with [ is seen as a list or { as a dict?
> ...
>

Some Smalltalk implementations have something that comes close:

st> 'https://python.org' asUrl retrieveContents

`asUrl` would be a string method returning a URL instance, which also has a 
convenient method `retrieveContents` wrapping an http client. Not hard to do 
with Python, I think this could be an interesting exercise for a learner.



From rosuav at gmail.com  Tue Jan  3 17:47:17 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 4 Jan 2017 09:47:17 +1100
Subject: How Best to Coerce Python Objects to Integers?
In-Reply-To: <586C28EC.8010607@stoneleaf.us>
References: <3d35c052-a4c2-44f9-b294-cb1a77d77477@googlegroups.com>
 <586C28EC.8010607@stoneleaf.us>
Message-ID: <CAPTjJmrm5a5dMGQLPev9A+DLdJP0z5wEmsN=C5CiaYu8-mB=kg@mail.gmail.com>

On Wed, Jan 4, 2017 at 9:42 AM, Ethan Furman <ethan at stoneleaf.us> wrote:
> Aside from calling "except Exception" a "naked except"

If you read the comments, you'll see that he originally had an actual
bare except clause, but then improved the code somewhat in response to
a recommendation that SystemExit etc not be caught.

ChrisA


From rosuav at gmail.com  Tue Jan  3 17:56:42 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 04 Jan 2017 10:56:42 +1200
Subject: Hey, I'm new to python so don't judge.
Message-ID: <3575573748@f38.n261.z1.binkp.net>

On Wed, Jan 4, 2017 at 10:49 AM,  <cr2001 at hotmail.co.nz> wrote:
> Im doing a new task from my teacher but i can't seem to find what is wrong
with this code. Can anyone help?
>
> #mynumber.py
> # this game uses a home made function
> import random
>
> #think of a number
> computer_number = number.randint(1,100)

What's wrong is that you aren't showing us the exception you get on this line. 
*Copy and paste* that exception - the whole thing. It's very helpful.

ChrisA



From rosuav at gmail.com  Tue Jan  3 17:59:18 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 04 Jan 2017 10:59:18 +1200
Subject: How Best to Coerce Python Objects to Integers?
Message-ID: <3493567800@f38.n261.z1.binkp.net>

On Wed, Jan 4, 2017 at 10:39 AM, Steve D'Aprano
<steve+python at pearwood.info> wrote:
> The problem here is not so much the use of try...except but the *intention*
> that "Anything whatsoever should be coerced to int". If you have something
> like:
>
> left_margin = int_or_else(ftp_server)
>
> that's surely a programming error that needs fixing, rather than something
> that should just return a default value.

Agreed. There are certainly times when you want to say "coerce any
*string* to an int", and there are times when you want to say "coerce
any string to int or None" (maybe you want to take the average of a whole lot 
of values, ignoring the ones that say "N/A"), but I don't know of any time I 
want to say "coerce any programming error to int or None", unless you count the 
exit code of a process.

I used the word "improved" rather loosely.

ChrisA



From python at deborahswanson.net  Tue Jan  3 18:05:20 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 15:05:20 -0800
Subject: Screwing Up looping in Generator
In-Reply-To: <CAPTjJmrzc1eCZyQKFCWVTkaL0a_JMz37+T5EjZv=Vx80Crj=SA@mail.gmail.com>
Message-ID: <006f01d26615$db87c460$27b23dae@sambora>

Chris Angelico wrote, on January 03, 2017 2:31 PM
> 
> On Wed, Jan 4, 2017 at 8:19 AM, Deborah Swanson 
> <python at deborahswanson.net> wrote:
> > while True:
> >   try:
> >     file = files.next()
> >   except StopIteration:
> >     break
> 
> Small side point: Try to avoid calling a generator object's 
> .next() method directly. Normally, when you _do_ want to do 
> this, you should be calling next(files). In Python 3, the 
> magic method is now __next__(), which emphasizes that it's 
> for defining, not calling.
> 
> As others have pointed out, though, the for loop is the 
> correct tool for this job.
> 
> ChrisA

Ok, I learned how to use generators in Python 2.7.8, which may be
different from Python 3 for generators. But I learned from MIT's online
introduction to python course, and they certainly seem to know python
well. So what is the correct way to call the generator's next yield in
Python 3? We only learned to use the next function. If you don't use the
next function, what do you use?

And yes, we usually used for loops for generators, unless you don't know
when the generator will be exhausted. As in this case, where the number
of files the generator can provide is unknown. Then we used the while
True, break on StopIteration method.



From flebber.crue at gmail.com  Tue Jan  3 18:09:40 2017
From: flebber.crue at gmail.com (Sayth Renshaw)
Date: Wed, 04 Jan 2017 11:09:40 +1200
Subject: Screwing Up looping in Generator
References: <2751329663@f38.n261.z1.binkp.net>
Message-ID: <3187615694@f38.n261.z1.binkp.net>

For completeness I was close this is the working code.

def get_list_of_names(generator_arg):
    name_set = set()
    for name in generator_arg:
        base = os.path.basename(name.name)
        filename = os.path.splitext(base)[0]
        name_set.add(filename)
    return name_set


def data_attr(roots):
    """Get the root object and iter items."""
    for name in names:
        directory = "output"
        write_name = name + ".csv"
        with open(os.path.join(directory, write_name), 'w', newline='') as
csvf:
            race_writer = csv.writer(csvf, delimiter=','
)


thanks for your time and assistance. It's much appreciated

Sayth



From ethan at stoneleaf.us  Tue Jan  3 18:09:52 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 03 Jan 2017 15:09:52 -0800
Subject: How Best to Coerce Python Objects to Integers?
In-Reply-To: <CAPTjJmrm5a5dMGQLPev9A+DLdJP0z5wEmsN=C5CiaYu8-mB=kg@mail.gmail.com>
References: <3d35c052-a4c2-44f9-b294-cb1a77d77477@googlegroups.com>
 <586C28EC.8010607@stoneleaf.us>
 <CAPTjJmrm5a5dMGQLPev9A+DLdJP0z5wEmsN=C5CiaYu8-mB=kg@mail.gmail.com>
Message-ID: <586C2F40.3050806@stoneleaf.us>

On 01/03/2017 02:47 PM, Chris Angelico wrote:
> On Wed, Jan 4, 2017 at 9:42 AM, Ethan Furman wrote:

>> Aside from calling "except Exception" a "naked except"
>
> If you read the comments, you'll see that he originally had an actual
> bare except clause, but then improved the code somewhat in response to
> a recommendation that SystemExit etc not be caught.

I did read the comments and noticed the reasons for the improved code; fixing the article to not use the "naked except" phrase would be another improvement.

And, of course, whether or not "except Exception" is too broad depends on the use-case.

--
~Ethan~


From grant.b.edwards at gmail.com  Tue Jan  3 18:13:11 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Tue, 3 Jan 2017 23:13:11 +0000 (UTC)
Subject: Clickable hyperlinks
References: <CABicbJLxh3qSAb5J9fTadWVA1PY-6bopY45jWgL9XX_k+oVY3w@mail.gmail.com>
 <003f01d26609$36cd78e0$27b23dae@sambora>
Message-ID: <o4hb66$4sf$1@blaine.gmane.org>

On 2017-01-03, Deborah Swanson <python at deborahswanson.net> wrote:

> I'm sorry, I should have said a GUI console because I wouldn't expect a
> text-based console to produce clickable links.

What's a "GUI console"?

-- 
Grant Edwards               grant.b.edwards        Yow! I want you to MEMORIZE
                                  at               the collected poems of
                              gmail.com            EDNA ST VINCENT MILLAY
                                                   ... BACKWARDS!!



From rosuav at gmail.com  Tue Jan  3 18:16:56 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 04 Jan 2017 11:16:56 +1200
Subject: Hey, I'm new to python so don't judge.
Message-ID: <1279173106@f38.n261.z1.binkp.net>

On Wed, Jan 4, 2017 at 11:03 AM, Erik <python at lucidity.plus.com> wrote:
> I doubt it's getting that far (I can see at least one syntax error in the
> code pasted).

True true. In any case, the point is to copy and paste the error message. 
Callum, please, copy and paste it.

ChrisA



From python at deborahswanson.net  Tue Jan  3 18:21:10 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 15:21:10 -0800
Subject: Screwing Up looping in Generator
In-Reply-To: <CAG93HwFz8LNGy+7UEE1x+GkvSX8D0GA_OJpg77_nkfeuwGkK2w@mail.gmail.com>
Message-ID: <007401d26618$11f605f0$27b23dae@sambora>

 

-----Original Message-----
From: Matt Wheeler [mailto:m at funkyhat.org] 
Sent: Tuesday, January 03, 2017 1:47 PM
To: python at deborahswanson.net; Sayth Renshaw; python-list at python.org
Subject: Re: Screwing Up looping in Generator


On Tue, 3 Jan 2017 at 20:17 Deborah Swanson <python at deborahswanson.net>
wrote:

> What's the code for your generator? And I don't see where you
> call 'next'.

I think you're expecting

        for file in rootobs

to get the next yield for you from rootobs, but unless someone corrects
me, I don't think you can expect a 'for' statement to do that. You need
to have a 'next' statement inside your for loop to get the next yield
from the generator.




Yes, you absolutely can expect a for statement to do that. It will
accept any iterable as its `y`. 
 
>> And here is someone correcting me, which I sort of suspected there
might be. Yes, 
>> range is an iterator, but I didn't know a generator could also be
used as an iterator.  
>> Makes perfect sense though, a generator does dispense its yields in
the sequence 
>> defined by the generator.


`for x in y: stuff(x)` is effectively syntactic sugar for:


iterator = iter(y)
while True:
    try:
        x = next(iterator)
    except(StopIteration):
        break
    stuff(x)

Manually calling `next()` inside a `while True:` is quite an unusual
thing to do. 
 
>> And you don't need to do it very often. The only use case I know is
this one, where the number of yields the generator can output is unknown
(here, the number of files the generator can access is unknown). You
might recall that the original poster wanted to use a while, but didn't
know how to terminate it. At least that's how I interpreted what he was
saying.


range() is not part of the for syntax at all, it's completely separate,
it simply returns an iterator which the for loop can use, like any
other. 
--  
 
>> I see that now, I just didn't know a generator could be used as an
iterator.

--
Matt Wheeler
http://funkyh.at



From no.email at nospam.invalid  Tue Jan  3 18:22:10 2017
From: no.email at nospam.invalid (Paul Rubin)
Date: Tue, 03 Jan 2017 15:22:10 -0800
Subject: Simulating int arithmetic with wrap-around
References: <58667385$0$1609$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <8737gz4tlp.fsf@nightsong.com>

Steve D'Aprano <steve+python at pearwood.info> writes:
> Again, assume both operands are in range for an N-bit signed integer. What's
> a good way to efficiently, or at least not too inefficiently, do the
> calculations in Python?

My first thought is towards the struct module, especially if you want to
handle a bunch of such integers at the same time.  Or maybe the array
module or some combination.  Or a C extension.


From steve+python at pearwood.info  Tue Jan  3 18:26:08 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 11:26:08 +1200
Subject: How Best to Coerce Python Objects to Integers?
References: <980704833@f38.n261.z1.binkp.net>
Message-ID: <1809108326@f38.n261.z1.binkp.net>

On Wed, 4 Jan 2017 10:09 am, Ethan Furman wrote:

> And, of course, whether or not "except Exception" is too broad depends on
> the use-case.

I'm having trouble thinking of *any* use-case where this would be useful. His 
intention, it seems, is to write a function which simply cannot fail, 
presumably so that he can write code which consumes the output and just keeps 
going no matter what he throws at it:

graph = make_graph()
incoming_data = [1, 12, 7, "hello", None, [], {}, 5] for obj in incoming_data:
    graph.draw_point(int_or_else(obj))


But of course that's impossible:

class Evil:
    def __int__(self):
        os.abort()

Or for that matter:

class Evil:
    def __int__(self):
        time.sleep(2147483647)



So his code still can fail under some circumstances. And so it should. Why is 
my input data including such evil objects? I should find out why. I'm having 
trouble seeing how it could be anything but a programming bug.


He gives the rationale for this function:

    A scenario that? ?s more realistic than the Unintable class might
    be a class that wraps an industrial sensor. Calling int() on an
    instance normally returns a value representing pressure or
    temperature. However, it might reasonably raise a
    SensorNotReadyError.

Okay. Let's suppose it can return either an integer as a string, some arbitrary 
non-numeric string to indicate a sensor error, or raises SensorNotReadyError. 
Then this would be an appropriate function to use:

def int_or_else(value):
    try:
        return int(value)
    except ValueError:
        assert isinstance(value, str)
        # consider logging the error?
        return None
    except SensorNotReadyError:
        return None


Now when he connects up to the sensor and starts reading values, it will work, 
but if his input gets contaminated with arbitrary junk objects (a sign of a 
programming bug in his code) he will find out about it.


One possible use-case might be something like Excel, where there are two data 
types: numbers, and text, and numeric operations on text will just skip them 
altogether. If you were to build an object-oriented spreadsheet, where the 
cells can contain any object not just numbers and text, then you could 
potentially have a situation like:

        Column A
Row 1:  1
Row 2:  ftp_server()
Row 3:  2
Row 4:  3
Row 5:  =sum(A1:A4)

and you (arguably) want the result to be 6 rather than some error. Or do you? I 
can make a good case for skipping text cells, as Excel does, but I'm not sure 
that ftp_server should be skipped. So I'll count that as a use-case, but a 
dubious one.

Another possible use-case might be the REPL for an interpreter, where you want 
the REPL to keep going no matter what exceptions take place. But I don't think 
this is the right way to do that, and it's not how the Python REPL works 
either.

Other than that, I'm not seeing any use-case where this sort of thing is 
anything but a bad idea.





--
Steve
? ?Cheer up,? ? they said, ? ?things could be worse.? ? So I cheered up, and
sure
enough, things got worse.



From python at lucidity.plus.com  Tue Jan  3 18:30:26 2017
From: python at lucidity.plus.com (Erik)
Date: Tue, 3 Jan 2017 23:30:26 +0000
Subject: Clickable hyperlinks
In-Reply-To: <001e01d265fa$0c639d50$27b23dae@sambora>
References: <001e01d265fa$0c639d50$27b23dae@sambora>
Message-ID: <4e756eb9-842b-98fe-3fa1-3b05baebe71a@lucidity.plus.com>

Hi.

On 03/01/17 19:46, Deborah Swanson wrote:
> Excel has a formula:

When you start a new topic on the list, could you please write a new 
message rather than replying to an existing message and changing the 
title/subject?

For those reading the list in a threaded email client, this message is 
shown as a continuation of your "Cleaning up conditionals" thread, and 
that whole thread in turn shows up as a continuation of the "mentor 
training python Romania with certification" discussion (which you had 
presumably "reply"ed to originally) ...

Thanks. E.


From python at deborahswanson.net  Tue Jan  3 18:32:04 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 15:32:04 -0800
Subject: Clickable hyperlinks
In-Reply-To: <o4hb66$4sf$1@blaine.gmane.org>
Message-ID: <007b01d26619$97de4eb0$27b23dae@sambora>

Grant Edwards wrote, on January 03, 2017 3:13 PM
> 
> On 2017-01-03, Deborah Swanson <python at deborahswanson.net> wrote:
> 
> > I'm sorry, I should have said a GUI console because I 
> wouldn't expect 
> > a text-based console to produce clickable links.
> 
> What's a "GUI console"?
> 
> -- 
> Grant Edwards               grant.b.edwards        Yow! I 
> want you to MEMORIZE
>                                   at               the 
> collected poems of
>                               gmail.com            EDNA ST 
> VINCENT MILLAY

The GUI consoles I have are in Pycharm, the IDLE that comes with
Anaconda, and Spyder. PyCharm and IDLE both ask for internet access when
I open them, so they're capable of opening links, but whether that means
their output space is capable of handling clickable links I don't know.

I do know printing a full url with the %s specifier or entering a url
and clicking enter just gives you the plain text url. Obviously, not all
GUI consoles are enabled recognize and make clickable links from
correctly formatted urls.

I was hoping there was some functionality in python to make clickable
links. Could be a package, if the core language doesn't have it.



From no.email at nospam.invalid  Tue Jan  3 18:33:09 2017
From: no.email at nospam.invalid (Paul Rubin)
Date: Tue, 03 Jan 2017 15:33:09 -0800
Subject: Cleaning up conditionals
References: <CAMPXz=rb=D8pMBa7if4ZXMd9YN4KHtT+0y+mTy1WLDgEdhAH=A@mail.gmail.com>
 <003501d262fc$90a70030$27b23dae@sambora>
 <mailman.55.1483143930.2395.python-list@python.org>
Message-ID: <87y3yr3eiy.fsf@nightsong.com>

"Deborah Swanson" <python at deborahswanson.net> writes:
> I'm still wondering if these 4 lines can be collapsed to one or two
> lines.

In the trade that's what we call a "code smell", a sign that code
(even if it works) should probably be re-thought after taking a step
back to understand what it is really trying to do.

What you seem to want is to take two strings, and if exactly one of them
is empty, then change the empty one to be the same as the non-empty one.
Leaving aside the subscripts and just calling them x and y,

   x, y = x or y, y or x

is a concise way to do it.

That's also smelly since 1) it's overly cute, and 2) it's not clear to
me why you'd want to do this operation.  It seems like an odd thing to
want so maybe there's some different way to solve the surrounding
problem.  If you want to describe the actual application and context
where this appears, that might get some helpful comments.


From rosuav at gmail.com  Tue Jan  3 18:34:59 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 4 Jan 2017 10:34:59 +1100
Subject: Screwing Up looping in Generator
In-Reply-To: <006f01d26615$db87c460$27b23dae@sambora>
References: <CAPTjJmrzc1eCZyQKFCWVTkaL0a_JMz37+T5EjZv=Vx80Crj=SA@mail.gmail.com>
 <006f01d26615$db87c460$27b23dae@sambora>
Message-ID: <CAPTjJmoTehb94xKfgUAPsYw5Sd54SxtMT5t-pi1f35vTCFLJxg@mail.gmail.com>

On Wed, Jan 4, 2017 at 10:05 AM, Deborah Swanson
<python at deborahswanson.net> wrote:
> Ok, I learned how to use generators in Python 2.7.8, which may be
> different from Python 3 for generators. But I learned from MIT's online
> introduction to python course, and they certainly seem to know python
> well. So what is the correct way to call the generator's next yield in
> Python 3? We only learned to use the next function. If you don't use the
> next function, what do you use?

The built-in next function, not the next method.

# don't do this
gen.next()

# do this
next(gen)

ChrisA


From steve+python at pearwood.info  Tue Jan  3 18:39:20 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 10:39:20 +1100
Subject: How Best to Coerce Python Objects to Integers?
References: <3d35c052-a4c2-44f9-b294-cb1a77d77477@googlegroups.com>
 <586C28EC.8010607@stoneleaf.us>
 <CAPTjJmrm5a5dMGQLPev9A+DLdJP0z5wEmsN=C5CiaYu8-mB=kg@mail.gmail.com>
 <mailman.170.1483483640.2395.python-list@python.org>
Message-ID: <586c3629$0$1606$c3e8da3$5496439d@news.astraweb.com>

On Wed, 4 Jan 2017 09:47 am, Chris Angelico wrote:

> On Wed, Jan 4, 2017 at 9:42 AM, Ethan Furman <ethan at stoneleaf.us> wrote:
>> Aside from calling "except Exception" a "naked except"
> 
> If you read the comments, you'll see that he originally had an actual
> bare except clause, but then improved the code somewhat in response to
> a recommendation that SystemExit etc not be caught.

But why? That makes no sense. If his intention is to return None on failure,
no matter what happens, then he *should* catch SystemExit. Otherwise:

class Unint:
    def __int__(self):
        raise SystemExit

int_or_else(Unint)


will exit instead of returning None. Surely that's not what he wants, given
that he wants to cover up other programming errors like NameError and
TypeError?

The problem here is not so much the use of try...except but the *intention*
that "Anything whatsoever should be coerced to int". If you have something
like:

left_margin = int_or_else(ftp_server)

that's surely a programming error that needs fixing, rather than something
that should just return a default value.



-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From python at lucidity.plus.com  Tue Jan  3 18:44:50 2017
From: python at lucidity.plus.com (Erik)
Date: Tue, 3 Jan 2017 23:44:50 +0000
Subject: Screwing Up looping in Generator
In-Reply-To: <006101d2660e$cdca05b0$27b23dae@sambora>
References: <006101d2660e$cdca05b0$27b23dae@sambora>
Message-ID: <d3b16c72-3db0-e318-e4c7-bd466e0ac70a@lucidity.plus.com>

Hi,

On 03/01/17 22:14, Deborah Swanson wrote:
> ...you have to create the generator object first and use it to call the
> next function. And I really don't think you can use a generator as your
> range in a for loop. So I'd use a 'while True', and break out of the
> loop when you hit the StopIteration exception:
>
> files = rootobs()
>
> while True:
>   try:
>     file = files.next()
>   except StopIteration:
>     break
>
>     base = os.path.basename(file.name)
>        .
>        .	
>        .
>       (etc)

What you have done there is taken an understanding of the underlying 
machinery that allows the 'for' loop to be syntactic sugar over any 
iterable and spelled it out, instead of just using 'for'! Without all 
that, your example is:

for file in rootobs():
   base = os.path.basename(file.name)
   .
   .
   .
   (etc)

[In fact, the machinery would also cope with the return value from 
rootobs() being an iterable but not an iterator by using "files = 
iter(rootobjs)"].



You seem to be reading up on how the stuff works under the covers (i.e., 
from the point of view of an implementer of a class or library) and then 
suggesting that that's what the *caller* of that class or library needs 
to do. They don't - for a caller, 'for x in seq:' is all they need to 
know - the mechanics are handled by the interpreter coupled with the 
dunder methods that the class may implement.


E.


From cr2001 at hotmail.co.nz  Tue Jan  3 18:49:14 2017
From: cr2001 at hotmail.co.nz (cr2001 at hotmail.co.nz)
Date: Tue, 3 Jan 2017 15:49:14 -0800 (PST)
Subject: Hey, I'm new to python so don't judge.
Message-ID: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>

Im doing a new task from my teacher but i can't seem to find what is wrong with this code. Can anyone help?

#mynumber.py
# this game uses a home made function
import random

#think of a number
computer_number = number.randint(1,100)

#create the function is_same()
def is_same(target, number:
        if target == number:
            result="win"
        elif target > number:
            result="low"
        else:
            result="high"
        return result

# start the game
print("hello. \nI have thought of a number between 1 and 100.")

#collect the user's guess as an interger
guess = int(input("Can you guess it? "))
#Use our function
higher_or_lower = is_same(computer_number, guess)
#run the game untill the user is correct
while higher_or_lower != "win"
    if higher_or_lower == "to low"
         guess = int(input("Sorry, you are too low. Try again."))
    else:
        guess = int(input("Sorry your are too high. Try again."))

    higher_or_lower = is_same(computer_number, guess)

#end of game
input("Correct!\nWell Done\n\n\nPress RETURN to exit.")
            
            
            



From python at lucidity.plus.com  Tue Jan  3 18:53:16 2017
From: python at lucidity.plus.com (Erik)
Date: Tue, 3 Jan 2017 23:53:16 +0000
Subject: Screwing Up looping in Generator
In-Reply-To: <006f01d26615$db87c460$27b23dae@sambora>
References: <006f01d26615$db87c460$27b23dae@sambora>
Message-ID: <8feb9bc0-cc89-97d6-589a-fe9b1072ff88@lucidity.plus.com>

On 03/01/17 23:05, Deborah Swanson wrote:
> And yes, we usually used for loops for generators, unless you don't know
> when the generator will be exhausted. As in this case, where the number
> of files the generator can provide is unknown. Then we used the while
> True, break on StopIteration method.

Out of interest, *why* was it deemed necessary to do something different 
if you don't know how many items the generator will generate? Was any 
rationale given for that?

for x in foo:
   bar(x)

... where foo is any iterable (something that has a __iter__ method 
defined - including generators) will just bind each value in turn to 'x' 
and will exit when the StopIteration exception is raised under the 
covers by the iterator that is iterating over the iterable.

Some generators are infinite (and their iterator will never raise a 
StopIteration exception).

E.


From steve+python at pearwood.info  Tue Jan  3 18:56:16 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 11:56:16 +1200
Subject: Clickable hyperlinks
References: <1124150781@f38.n261.z1.binkp.net>
Message-ID: <1026903396@f38.n261.z1.binkp.net>

On Wed, 4 Jan 2017 10:32 am, Deborah Swanson wrote:


> The GUI consoles I have are in Pycharm, the IDLE that comes with
> Anaconda, and Spyder. PyCharm and IDLE both ask for internet access when
> I open them, so they're capable of opening links, but whether that means
> their output space is capable of handling clickable links I don't know.
>
> I do know printing a full url with the %s specifier or entering a url
> and clicking enter just gives you the plain text url. Obviously, not all
> GUI consoles are enabled recognize and make clickable links from
> correctly formatted urls.
>
> I was hoping there was some functionality in python to make clickable
> links. Could be a package, if the core language doesn't have it.

Unfortunately there is no such thing as an application- independent "clickable 
link".

Excel can make clickable links, because it only has to deal with a single suite 
of related applications: Excel, Word, and the rest of Microsoft Office. 
Likewise LibreOffice.

But Python has to deal with an infinite number of potential or hypothetical 
consoles, and there is no standard for "clickable links" that all, or even 
most, consoles understand.

Python can't force the console to treat something as a clickable link, if the 
console has no capacity for clickable links. Nor can Python predict what format 
the console uses to recognise a link.

The best you can do is to experiment with a couple of simple formats and see 
which, if any, your console understands:

# HTML
<a href="http://www.example.com">Example.</a>

# URL in angle brackets
Example <http://www.example.com>

# URL alone
http://www.example.com

# I can't remember what these are called
<url:http://www.example.com>

# Markup
[Example](http://www.example.com)

# Rest
`Example <http://www.example.com>`_





--
Steve
? ?Cheer up,? ? they said, ? ?things could be worse.? ? So I cheered up, and
sure
enough, things got worse.



From rosuav at gmail.com  Tue Jan  3 18:56:42 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 4 Jan 2017 10:56:42 +1100
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
Message-ID: <CAPTjJmrwnjd+em2beKAYyZAe6k6EJg4xO2Brzg=BOUzG+SFE3Q@mail.gmail.com>

On Wed, Jan 4, 2017 at 10:49 AM,  <cr2001 at hotmail.co.nz> wrote:
> Im doing a new task from my teacher but i can't seem to find what is wrong with this code. Can anyone help?
>
> #mynumber.py
> # this game uses a home made function
> import random
>
> #think of a number
> computer_number = number.randint(1,100)

What's wrong is that you aren't showing us the exception you get on
this line. *Copy and paste* that exception - the whole thing. It's
very helpful.

ChrisA


From rosuav at gmail.com  Tue Jan  3 18:59:18 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 4 Jan 2017 10:59:18 +1100
Subject: How Best to Coerce Python Objects to Integers?
In-Reply-To: <586c3629$0$1606$c3e8da3$5496439d@news.astraweb.com>
References: <3d35c052-a4c2-44f9-b294-cb1a77d77477@googlegroups.com>
 <586C28EC.8010607@stoneleaf.us>
 <CAPTjJmrm5a5dMGQLPev9A+DLdJP0z5wEmsN=C5CiaYu8-mB=kg@mail.gmail.com>
 <mailman.170.1483483640.2395.python-list@python.org>
 <586c3629$0$1606$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmqwOV680n=vJgG4atC6bULHtF70HRmcmdm06XZALue6jg@mail.gmail.com>

On Wed, Jan 4, 2017 at 10:39 AM, Steve D'Aprano
<steve+python at pearwood.info> wrote:
> The problem here is not so much the use of try...except but the *intention*
> that "Anything whatsoever should be coerced to int". If you have something
> like:
>
> left_margin = int_or_else(ftp_server)
>
> that's surely a programming error that needs fixing, rather than something
> that should just return a default value.

Agreed. There are certainly times when you want to say "coerce any
*string* to an int", and there are times when you want to say "coerce
any string to int or None" (maybe you want to take the average of a
whole lot of values, ignoring the ones that say "N/A"), but I don't
know of any time I want to say "coerce any programming error to int or
None", unless you count the exit code of a process.

I used the word "improved" rather loosely.

ChrisA


From steve+python at pearwood.info  Tue Jan  3 19:00:36 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 12:00:36 +1200
Subject: Hey, I'm new to python so don't judge.
References: <2481169416@f38.n261.z1.binkp.net>
Message-ID: <706562471@f38.n261.z1.binkp.net>

On Wed, 4 Jan 2017 11:16 am, Callum Robinson wrote:

> My apologizes but i'm quite new and would need instructions to what
> information you need me to get.


Do you know how to copy and paste from the terminal window?

Somewhere on the screen you see something like:


    x = 23 + )
             ^
SyntaxError: invalid syntax



You should copy and paste *all* of the error message, as much as you can see.





--
Steve
? ?Cheer up,? ? they said, ? ?things could be worse.? ? So I cheered up, and
sure
enough, things got worse.



From cr2001 at hotmail.co.nz  Tue Jan  3 19:02:15 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 3 Jan 2017 16:02:15 -0800 (PST)
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
Message-ID: <de17ea17-a783-4b03-bdd6-7ac5afa63c51@googlegroups.com>

When i check the code it comes up with invalid syntax and my writing line gets re directed here

def is_same(target, number:
        if target == number:
            result="win"
        elif target > number:
            result="low"
        else:
            result="high"
        return result


From python at lucidity.plus.com  Tue Jan  3 19:03:03 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 4 Jan 2017 00:03:03 +0000
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <CAPTjJmrwnjd+em2beKAYyZAe6k6EJg4xO2Brzg=BOUzG+SFE3Q@mail.gmail.com>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <CAPTjJmrwnjd+em2beKAYyZAe6k6EJg4xO2Brzg=BOUzG+SFE3Q@mail.gmail.com>
Message-ID: <cc7ace5b-46ca-0727-2be6-a173f89e9df1@lucidity.plus.com>

On 03/01/17 23:56, Chris Angelico wrote:
> On Wed, Jan 4, 2017 at 10:49 AM,  <cr2001 at hotmail.co.nz> wrote:
>> #think of a number
>> computer_number = number.randint(1,100)
>
> What's wrong is that you aren't showing us the exception you get on
> this line. *Copy and paste* that exception - the whole thing. It's
> very helpful.

I doubt it's getting that far (I can see at least one syntax error in 
the code pasted).

cr2001: I echo Chris's sentiment though - what is the error you are 
seeing (in it's entirety)?

E.



From steve+python at pearwood.info  Tue Jan  3 19:10:00 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 12:10:00 +1200
Subject: How Best to Coerce Python Objects to Integers?
References: <1909730512@f38.n261.z1.binkp.net>
Message-ID: <2445380791@f38.n261.z1.binkp.net>

On Wed, 4 Jan 2017 11:22 am, Erik wrote:

> On 03/01/17 22:47, Chris Angelico wrote:
>> On Wed, Jan 4, 2017 at 9:42 AM, Ethan Furman <ethan at stoneleaf.us> wrote:
>>> Aside from calling "except Exception" a "naked except"
>>
>> If you read the comments, you'll see that he originally had an actual
>> bare except clause, but then improved the code somewhat in response to
>> a recommendation that SystemExit etc not be caught.
>
> But, as stated at the top of the article, his brief was: "The strings
> come from a file that a human has typed in, so even though most of the
> values are good, a few will have errors ('25C') that int() will reject.".

Right. And from there he starts worrying about the case where the inputs aren't 
strings at all, or they're weird exotic objects with nasty __int__ methods. 
That's overkill and can only hide programming errors.


> What he *should* have done is just validated his input strings before
> presenting the string to int() - i.e., process the input with knowledge
> that is specific to the problem domain before calling the
> general-purpose function.

That's the Look Before You Leap solution. But in this case, given the scenario 
described (a text file with a few typos), the best way is to ask for 
forgiveness rather than permission:

def int_or_else(value):
    try:
        return int(value)
    else ValueError:
        pass


Why is this better? In the given scenario, errors are rare. Most values are 
good, with only a few typos, so it is wasteful to parse the string twice, once 
to validate it and once to generate the int. Besides, there's probably no 
Python code you can write which will validate an int as fast as the int() 
function itself.


[...]
> Instead, he tried to patch around int() rejecting the strings. And then
> decided that he'd patch around int() rejecting things that weren't even
> strings even though that's not what the function has (apparently) been
> specified to receive.

Indeed.


Another thought: if he is receiving human generated input, there is an argument 
to be made for accepting "look alikes" -- e.g. maybe the data was entered by 
Aunt Tilly, who was a typist in the 1960s and can't break the habit of using l 
or I interchangeably for 1, and O for 0.




--
Steve
? ?Cheer up,? ? they said, ? ?things could be worse.? ? So I cheered up, and
sure
enough, things got worse.



From cs at zip.com.au  Tue Jan  3 19:10:30 2017
From: cs at zip.com.au (Cameron Simpson)
Date: Wed, 04 Jan 2017 12:10:30 +1200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
Message-ID: <1881369740@f38.n261.z1.binkp.net>

On 03Jan2017 12:57, Steve D'Aprano <steve+python at pearwood.info> wrote:
>I dislike the Unix-style Vim/Emacs text editors, I prefer a traditional
>GUI-based editor. So my "IDE" is:
>- Firefox, for doing searches and looking up documentation;
>- an GUI programmer's editor, preferably one with a tab-based
>  interface, such as geany or kate;
>- a tab-based terminal.

"traditional GUI-based editor"

For those of us who spent a lot of our earlier time on terminals (actual 
physical terminals) we consider GUIs "new fangled".

Just narking,
Cameron Simpson <cs at zip.com.au>



From steve+python at pearwood.info  Tue Jan  3 19:15:56 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 12:15:56 +1200
Subject: Hey, I'm new to python so don't judge.
References: <4092501290@f38.n261.z1.binkp.net>
Message-ID: <3844402364@f38.n261.z1.binkp.net>

On Wed, 4 Jan 2017 12:04 pm, Callum Robinson wrote:

> Traceback (most recent call last):
>   File "D:/Python/random.py", line 6, in <module>
>     computer_number = number.randint(1, 100)
> NameError: name 'number' is not defined


That's exactly what we need to see! The full traceback, thank you!

You're asking Python to get the variable "number", and call the randint method. 
But:

- you don't have a variable called "number";

NameError: name 'number' is not defined


- and even if you did, that's not how you get a random number. What you want
is:

computer_number = random.randint(1, 100)






--
Steve
? ?Cheer up,? ? they said, ? ?things could be worse.? ? So I cheered up, and
sure
enough, things got worse.



From cr2001 at hotmail.co.nz  Tue Jan  3 19:16:36 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 3 Jan 2017 16:16:36 -0800 (PST)
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <mailman.182.1483488187.2395.python-list@python.org>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <CAPTjJmrwnjd+em2beKAYyZAe6k6EJg4xO2Brzg=BOUzG+SFE3Q@mail.gmail.com>
 <cc7ace5b-46ca-0727-2be6-a173f89e9df1@lucidity.plus.com>
 <mailman.182.1483488187.2395.python-list@python.org>
Message-ID: <c4dc7fa8-1e77-4038-8e00-c5ccab9b6faa@googlegroups.com>

On Wednesday, January 4, 2017 at 1:03:18 PM UTC+13, Erik wrote:
> On 03/01/17 23:56, Chris Angelico wrote:
> > On Wed, Jan 4, 2017 at 10:49 AM,  <cr2001 at hotmail.co.nz> wrote:
> >> #think of a number
> >> computer_number = number.randint(1,100)
> >
> > What's wrong is that you aren't showing us the exception you get on
> > this line. *Copy and paste* that exception - the whole thing. It's
> > very helpful.
> 
> I doubt it's getting that far (I can see at least one syntax error in 
> the code pasted).
> 
> cr2001: I echo Chris's sentiment though - what is the error you are 
> seeing (in it's entirety)?
> 
> E.

My apologizes but i'm quite new and would need instructions to what information you need me to get.


From rosuav at gmail.com  Tue Jan  3 19:16:57 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 4 Jan 2017 11:16:57 +1100
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <cc7ace5b-46ca-0727-2be6-a173f89e9df1@lucidity.plus.com>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <CAPTjJmrwnjd+em2beKAYyZAe6k6EJg4xO2Brzg=BOUzG+SFE3Q@mail.gmail.com>
 <cc7ace5b-46ca-0727-2be6-a173f89e9df1@lucidity.plus.com>
Message-ID: <CAPTjJmo=1+bQe-2OMOwikJj11ziQVm0fZKBeHEeTMbo718YBFw@mail.gmail.com>

On Wed, Jan 4, 2017 at 11:03 AM, Erik <python at lucidity.plus.com> wrote:
> I doubt it's getting that far (I can see at least one syntax error in the
> code pasted).

True true. In any case, the point is to copy and paste the error
message. Callum, please, copy and paste it.

ChrisA


From cs at zip.com.au  Tue Jan  3 19:20:18 2017
From: cs at zip.com.au (Cameron Simpson)
Date: Wed, 04 Jan 2017 12:20:18 +1200
Subject: trouble with cmd.Cmd and prompting
Message-ID: <1514283610@f38.n261.z1.binkp.net>

On 03Jan2017 16:57, Peter Otten <__peter__ at web.de> wrote:
>Cameron Simpson wrote:
>> On 03Jan2017 00:14, Dennis Lee Bieber <wlfraed at ix.netcom.com> wrote:
>>>On Tue, 3 Jan 2017 11:33:15 +1100, Cameron Simpson <cs at zip.com.au>
>>>declaimed the following:
>>>>I'm using cmd.Cmd to write a little FTP-like command line to interface to
>>>>a storage system of mine and encountering weird behaviour. When I enter a
>>>>command the next prompt appears _before_ the associated operation runs,
[...]
>>>Haven't used the module but there is something I find intriguing in the
>>>help system
>>>-=-=-=-=-
>>> Cmd.precmd(line)
>>>    Hook method executed just before the command line is interpreted, but
>>>after the input prompt is generated and issued.
>>>-=-=-=-=-
>>>"... AFTER the input prompt is ... issued"
[...]
>I don't believe Dennis' reading of the docs is correct, and the relevant
>part of the source (Python 3.4) does not show anything to support it:
[... code that runs as I had imagined ...]
>Is there something asynchronous in your command? Perhaps you can post a
>minimal runnable example that shows the odd behaviour.

In the commands themselves? No, but the storage system has lots of asynchronous 
activity.

I'm bothered by the fact that an empty command also shows this behaviour.

I will try to get a minimal example others can run.

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



From python at lucidity.plus.com  Tue Jan  3 19:22:17 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 4 Jan 2017 00:22:17 +0000
Subject: How Best to Coerce Python Objects to Integers?
In-Reply-To: <CAPTjJmrm5a5dMGQLPev9A+DLdJP0z5wEmsN=C5CiaYu8-mB=kg@mail.gmail.com>
References: <3d35c052-a4c2-44f9-b294-cb1a77d77477@googlegroups.com>
 <586C28EC.8010607@stoneleaf.us>
 <CAPTjJmrm5a5dMGQLPev9A+DLdJP0z5wEmsN=C5CiaYu8-mB=kg@mail.gmail.com>
Message-ID: <8e7195db-e33f-18e3-e1d9-74f9a458e69b@lucidity.plus.com>

On 03/01/17 22:47, Chris Angelico wrote:
> On Wed, Jan 4, 2017 at 9:42 AM, Ethan Furman <ethan at stoneleaf.us> wrote:
>> Aside from calling "except Exception" a "naked except"
>
> If you read the comments, you'll see that he originally had an actual
> bare except clause, but then improved the code somewhat in response to
> a recommendation that SystemExit etc not be caught.

But, as stated at the top of the article, his brief was: "The strings 
come from a file that a human has typed in, so even though most of the 
values are good, a few will have errors ('25C') that int() will reject.".

What he *should* have done is just validated his input strings before 
presenting the string to int() - i.e., process the input with knowledge 
that is specific to the problem domain before calling the 
general-purpose function.

He mentions temperature sensors, so perhaps stripping a trailing 'c' or 
'C' is a reasonable thing to do (or even, if there's a trailing 'f' or 
'F', performing a numerical conversion after the value is known).

Instead, he tried to patch around int() rejecting the strings. And then 
decided that he'd patch around int() rejecting things that weren't even 
strings even though that's not what the function has (apparently) been 
specified to receive.

The "bulletproof" result will convert "25C" to None even though 25 is 
probably a reasonable result for that string in his domain problem domain.

E.





From steve+python at pearwood.info  Tue Jan  3 19:26:08 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 11:26:08 +1100
Subject: How Best to Coerce Python Objects to Integers?
References: <3d35c052-a4c2-44f9-b294-cb1a77d77477@googlegroups.com>
 <586C28EC.8010607@stoneleaf.us>
 <CAPTjJmrm5a5dMGQLPev9A+DLdJP0z5wEmsN=C5CiaYu8-mB=kg@mail.gmail.com>
 <586C2F40.3050806@stoneleaf.us>
 <mailman.172.1483484981.2395.python-list@python.org>
Message-ID: <586c4122$0$1621$c3e8da3$5496439d@news.astraweb.com>

On Wed, 4 Jan 2017 10:09 am, Ethan Furman wrote:

> And, of course, whether or not "except Exception" is too broad depends on
> the use-case.

I'm having trouble thinking of *any* use-case where this would be useful.
His intention, it seems, is to write a function which simply cannot fail,
presumably so that he can write code which consumes the output and just
keeps going no matter what he throws at it:

graph = make_graph()
incoming_data = [1, 12, 7, "hello", None, [], {}, 5]
for obj in incoming_data:
    graph.draw_point(int_or_else(obj))


But of course that's impossible:

class Evil:
    def __int__(self):
        os.abort()

Or for that matter:

class Evil:
    def __int__(self):
        time.sleep(2147483647)



So his code still can fail under some circumstances. And so it should. Why
is my input data including such evil objects? I should find out why. I'm
having trouble seeing how it could be anything but a programming bug.


He gives the rationale for this function:

    A scenario that?s more realistic than the Unintable class might
    be a class that wraps an industrial sensor. Calling int() on an
    instance normally returns a value representing pressure or
    temperature. However, it might reasonably raise a
    SensorNotReadyError.

Okay. Let's suppose it can return either an integer as a string, some
arbitrary non-numeric string to indicate a sensor error, or raises
SensorNotReadyError. Then this would be an appropriate function to use:

def int_or_else(value):
    try:
        return int(value)
    except ValueError:
        assert isinstance(value, str)
        # consider logging the error?
        return None
    except SensorNotReadyError:
        return None


Now when he connects up to the sensor and starts reading values, it will
work, but if his input gets contaminated with arbitrary junk objects (a
sign of a programming bug in his code) he will find out about it.


One possible use-case might be something like Excel, where there are two
data types: numbers, and text, and numeric operations on text will just
skip them altogether. If you were to build an object-oriented spreadsheet,
where the cells can contain any object not just numbers and text, then you
could potentially have a situation like:

        Column A
Row 1:  1
Row 2:  ftp_server()
Row 3:  2
Row 4:  3
Row 5:  =sum(A1:A4)

and you (arguably) want the result to be 6 rather than some error. Or do
you? I can make a good case for skipping text cells, as Excel does, but I'm
not sure that ftp_server should be skipped. So I'll count that as a
use-case, but a dubious one.

Another possible use-case might be the REPL for an interpreter, where you
want the REPL to keep going no matter what exceptions take place. But I
don't think this is the right way to do that, and it's not how the Python
REPL works either.

Other than that, I'm not seeing any use-case where this sort of thing is
anything but a bad idea.





-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From python at lucidity.plus.com  Tue Jan  3 19:26:12 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 4 Jan 2017 00:26:12 +0000
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <de17ea17-a783-4b03-bdd6-7ac5afa63c51@googlegroups.com>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <de17ea17-a783-4b03-bdd6-7ac5afa63c51@googlegroups.com>
Message-ID: <aaaddf7e-8835-4860-7338-69fc55376fbe@lucidity.plus.com>

Hi Callum,

On 04/01/17 00:02, Callum Robinson wrote:
 > When i check the code it comes up with invalid syntax and my writing 
line gets re directed here
 >
 > def is_same(target, number:
 >         if target == number:
 >             result="win"
 >         elif target > number:
 >             result="low"
 >         else:
 >             result="high"
 >         return result

OK, good. That implies it's something wrong with the function definition 
('def'). Look at that very carefully :)   (*)

E.

(*) My emoticon may give you a hint ...


From cr2001 at hotmail.co.nz  Tue Jan  3 19:27:33 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 3 Jan 2017 16:27:33 -0800 (PST)
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <mailman.184.1483489020.2395.python-list@python.org>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <CAPTjJmrwnjd+em2beKAYyZAe6k6EJg4xO2Brzg=BOUzG+SFE3Q@mail.gmail.com>
 <cc7ace5b-46ca-0727-2be6-a173f89e9df1@lucidity.plus.com>
 <CAPTjJmo=1+bQe-2OMOwikJj11ziQVm0fZKBeHEeTMbo718YBFw@mail.gmail.com>
 <mailman.184.1483489020.2395.python-list@python.org>
Message-ID: <40adacf3-b4de-4243-8cb5-6ea5fb74cf18@googlegroups.com>

On Wednesday, January 4, 2017 at 1:17:11 PM UTC+13, Chris Angelico wrote:
> On Wed, Jan 4, 2017 at 11:03 AM, Erik <python at lucidity.plus.com> wrote:
> > I doubt it's getting that far (I can see at least one syntax error in the
> > code pasted).
> 
> True true. In any case, the point is to copy and paste the error
> message. Callum, please, copy and paste it.
> 
> ChrisA

I'm sorry if I'm doing something wrong but all that is happening is when i try to run it a popup says Invalid syntax


From cr2001 at hotmail.co.nz  Tue Jan  3 19:30:53 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 3 Jan 2017 16:30:53 -0800 (PST)
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <mailman.186.1483489577.2395.python-list@python.org>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <de17ea17-a783-4b03-bdd6-7ac5afa63c51@googlegroups.com>
 <aaaddf7e-8835-4860-7338-69fc55376fbe@lucidity.plus.com>
 <mailman.186.1483489577.2395.python-list@python.org>
Message-ID: <5e69d496-f5d3-4aab-ae78-3d1d57d3aee4@googlegroups.com>

On Wednesday, January 4, 2017 at 1:26:26 PM UTC+13, Erik wrote:
> Hi Callum,
> 
> On 04/01/17 00:02, Callum Robinson wrote:
>  > When i check the code it comes up with invalid syntax and my writing 
> line gets re directed here
>  >
>  > def is_same(target, number:
>  >         if target == number:
>  >             result="win"
>  >         elif target > number:
>  >             result="low"
>  >         else:
>  >             result="high"
>  >         return result
> 
> OK, good. That implies it's something wrong with the function definition 
> ('def'). Look at that very carefully :)   (*)
> 
> E.
> 
> (*) My emoticon may give you a hint ...

I feel like im missing something so blatantly obvious. 


From cr2001 at hotmail.co.nz  Tue Jan  3 19:32:40 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 3 Jan 2017 16:32:40 -0800 (PST)
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <mailman.186.1483489577.2395.python-list@python.org>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <de17ea17-a783-4b03-bdd6-7ac5afa63c51@googlegroups.com>
 <aaaddf7e-8835-4860-7338-69fc55376fbe@lucidity.plus.com>
 <mailman.186.1483489577.2395.python-list@python.org>
Message-ID: <b846cee1-cf7c-4512-98d9-610b424497c2@googlegroups.com>

On Wednesday, January 4, 2017 at 1:26:26 PM UTC+13, Erik wrote:
> Hi Callum,
> 
> On 04/01/17 00:02, Callum Robinson wrote:
>  > When i check the code it comes up with invalid syntax and my writing 
> line gets re directed here
>  >
>  > def is_same(target, number:
>  >         if target == number:
>  >             result="win"
>  >         elif target > number:
>  >             result="low"
>  >         else:
>  >             result="high"
>  >         return result
> 
> OK, good. That implies it's something wrong with the function definition 
> ('def'). Look at that very carefully :)   (*)
> 
> E.
> 
> (*) My emoticon may give you a hint ...

I forgot a bloody bracket xD

and now theirs a new error ill try to figure this out on my own.


From python at lucidity.plus.com  Tue Jan  3 19:45:08 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 4 Jan 2017 00:45:08 +0000
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <5e69d496-f5d3-4aab-ae78-3d1d57d3aee4@googlegroups.com>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <de17ea17-a783-4b03-bdd6-7ac5afa63c51@googlegroups.com>
 <aaaddf7e-8835-4860-7338-69fc55376fbe@lucidity.plus.com>
 <mailman.186.1483489577.2395.python-list@python.org>
 <5e69d496-f5d3-4aab-ae78-3d1d57d3aee4@googlegroups.com>
Message-ID: <71b9f7e5-c255-435f-e7d6-3cc7abce35b4@lucidity.plus.com>

Hi Callum,

On 04/01/17 00:30, Callum Robinson wrote:
> I feel like im missing something so blatantly obvious.

That's because you are ;). I don't want to come across as patronising, 
but I want you to see it for yourself, so, here's a function definition 
similar to yours that doesn't have the same syntax error that yours does:

def foo(spam, ham):
     if spam == ham:
         return "same"
     return "different"

See the difference?

E.


From python at lucidity.plus.com  Tue Jan  3 19:47:55 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 4 Jan 2017 00:47:55 +0000
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <b846cee1-cf7c-4512-98d9-610b424497c2@googlegroups.com>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <de17ea17-a783-4b03-bdd6-7ac5afa63c51@googlegroups.com>
 <aaaddf7e-8835-4860-7338-69fc55376fbe@lucidity.plus.com>
 <mailman.186.1483489577.2395.python-list@python.org>
 <b846cee1-cf7c-4512-98d9-610b424497c2@googlegroups.com>
Message-ID: <f82721cc-89fc-336d-e0df-01a63223cee9@lucidity.plus.com>

On 04/01/17 00:32, Callum Robinson wrote:
> I forgot a bloody bracket xD

Cool, you got it ;) It's the sort of thing your brain will see instantly 
once you've done it a few times :D

> and now theirs a new error ill try to figure this out on my own.

You need to look back to Chris's original reply, I suspect (his reply 
was pointing out a runtime issue that will happen once the syntax issue 
is resolved) ...

E.



From python at deborahswanson.net  Tue Jan  3 19:50:03 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 16:50:03 -0800
Subject: Clickable hyperlinks
In-Reply-To: <4e756eb9-842b-98fe-3fa1-3b05baebe71a@lucidity.plus.com>
Message-ID: <008e01d26624$7c84a7d0$27b23dae@sambora>

Erik wrote, on January 03, 2017 3:30 PM
> To: python-list at python.org
> Subject: Re: Clickable hyperlinks
> 
> Hi.
> 
> On 03/01/17 19:46, Deborah Swanson wrote:
> > Excel has a formula:
> 
> When you start a new topic on the list, could you please write a new 
> message rather than replying to an existing message and changing the 
> title/subject?
> 
> For those reading the list in a threaded email client, this 
> message is 
> shown as a continuation of your "Cleaning up conditionals" 
> thread, and 
> that whole thread in turn shows up as a continuation of the "mentor 
> training python Romania with certification" discussion (which you had 
> presumably "reply"ed to originally) ...
> 
> Thanks. E.

Certainly. I've been on many other lists before (but none since about
2011), and no one complained of or even mentioned this problem. But if
it's a problem with some email readers now, I can easily just start a
new message.  Just being lazy and following old habits, I guess. ;)



From steve+python at pearwood.info  Tue Jan  3 19:56:17 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 11:56:17 +1100
Subject: Clickable hyperlinks
References: <o4hb66$4sf$1@blaine.gmane.org>
 <007b01d26619$97de4eb0$27b23dae@sambora>
 <mailman.176.1483486294.2395.python-list@python.org>
Message-ID: <586c4834$0$1591$c3e8da3$5496439d@news.astraweb.com>

On Wed, 4 Jan 2017 10:32 am, Deborah Swanson wrote:


> The GUI consoles I have are in Pycharm, the IDLE that comes with
> Anaconda, and Spyder. PyCharm and IDLE both ask for internet access when
> I open them, so they're capable of opening links, but whether that means
> their output space is capable of handling clickable links I don't know.
> 
> I do know printing a full url with the %s specifier or entering a url
> and clicking enter just gives you the plain text url. Obviously, not all
> GUI consoles are enabled recognize and make clickable links from
> correctly formatted urls.
> 
> I was hoping there was some functionality in python to make clickable
> links. Could be a package, if the core language doesn't have it.

Unfortunately there is no such thing as an application-
independent "clickable link".

Excel can make clickable links, because it only has to deal with a single
suite of related applications: Excel, Word, and the rest of Microsoft
Office. Likewise LibreOffice.

But Python has to deal with an infinite number of potential or hypothetical
consoles, and there is no standard for "clickable links" that all, or even
most, consoles understand.

Python can't force the console to treat something as a clickable link, if
the console has no capacity for clickable links. Nor can Python predict
what format the console uses to recognise a link.

The best you can do is to experiment with a couple of simple formats and see
which, if any, your console understands:

# HTML
<a href="http://www.example.com">Example.</a>

# URL in angle brackets
Example <http://www.example.com>

# URL alone
http://www.example.com

# I can't remember what these are called
<url:http://www.example.com>

# Markup
[Example](http://www.example.com)

# Rest
`Example <http://www.example.com>`_





-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From steve+python at pearwood.info  Tue Jan  3 20:00:36 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 12:00:36 +1100
Subject: Hey, I'm new to python so don't judge.
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <CAPTjJmrwnjd+em2beKAYyZAe6k6EJg4xO2Brzg=BOUzG+SFE3Q@mail.gmail.com>
 <cc7ace5b-46ca-0727-2be6-a173f89e9df1@lucidity.plus.com>
 <mailman.182.1483488187.2395.python-list@python.org>
 <c4dc7fa8-1e77-4038-8e00-c5ccab9b6faa@googlegroups.com>
Message-ID: <586c4936$0$1591$c3e8da3$5496439d@news.astraweb.com>

On Wed, 4 Jan 2017 11:16 am, Callum Robinson wrote:

> My apologizes but i'm quite new and would need instructions to what
> information you need me to get.


Do you know how to copy and paste from the terminal window?

Somewhere on the screen you see something like:


    x = 23 + )
             ^
SyntaxError: invalid syntax



You should copy and paste *all* of the error message, as much as you can
see.





-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From python at deborahswanson.net  Tue Jan  3 20:01:18 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 17:01:18 -0800
Subject: Screwing Up looping in Generator
In-Reply-To: <d3b16c72-3db0-e318-e4c7-bd466e0ac70a@lucidity.plus.com>
Message-ID: <009101d26626$0ecd9470$27b23dae@sambora>

Erik wrote, on January 03, 2017 3:45 PM
> 
> Hi,
> 
> On 03/01/17 22:14, Deborah Swanson wrote:
> > ...you have to create the generator object first and use it to call 
> > the next function. And I really don't think you can use a 
> generator as 
> > your range in a for loop. So I'd use a 'while True', and 
> break out of 
> > the loop when you hit the StopIteration exception:
> >
> > files = rootobs()
> >
> > while True:
> >   try:
> >     file = files.next()
> >   except StopIteration:
> >     break
> >
> >     base = os.path.basename(file.name)
> >        .
> >        .	
> >        .
> >       (etc)
> 
> What you have done there is taken an understanding of the underlying 
> machinery that allows the 'for' loop to be syntactic sugar over any 
> iterable and spelled it out, instead of just using 'for'! Without all 
> that, your example is:
> 
> for file in rootobs():
>    base = os.path.basename(file.name)
>    .
>    .
>    .
>    (etc)
> 
> [In fact, the machinery would also cope with the return value from 
> rootobs() being an iterable but not an iterator by using "files = 
> iter(rootobjs)"].
> 
> 
> 
> You seem to be reading up on how the stuff works under the 
> covers (i.e., 
> from the point of view of an implementer of a class or 
> library) and then 
> suggesting that that's what the *caller* of that class or 
> library needs 
> to do. They don't - for a caller, 'for x in seq:' is all they need to 
> know - the mechanics are handled by the interpreter coupled with the 
> dunder methods that the class may implement.
> 
> 
> E.

Ok, I'm in complete agreement with everything you said up to the last
paragraph, which I don't disagree with, I just don't see your point.

If you've read my last few posts you'll have seen me acknowledging that
normally a for loop is used, but a while and break on StopIteration is a
method that's useful when the output of the generator is unknown.

I haven't read through much documentation on generators, but I have
taken a course from MIT, in which a Computer Science professor gave us
several methods for working with generators, of which the while and
break on StopIteration method is one.  The original poster wanted to use
a while, and seemed to be saying he didn't know how many files the
generator he has would yield, so that was why I recommended the while
loop. Normally I would use a for loop too.
D.



From cr2001 at hotmail.co.nz  Tue Jan  3 20:04:29 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 3 Jan 2017 17:04:29 -0800 (PST)
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <mailman.187.1483490711.2395.python-list@python.org>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <de17ea17-a783-4b03-bdd6-7ac5afa63c51@googlegroups.com>
 <aaaddf7e-8835-4860-7338-69fc55376fbe@lucidity.plus.com>
 <mailman.186.1483489577.2395.python-list@python.org>
 <5e69d496-f5d3-4aab-ae78-3d1d57d3aee4@googlegroups.com>
 <71b9f7e5-c255-435f-e7d6-3cc7abce35b4@lucidity.plus.com>
 <mailman.187.1483490711.2395.python-list@python.org>
Message-ID: <3021b6e8-d843-413f-a62b-f51461ed1b49@googlegroups.com>

On Wednesday, January 4, 2017 at 1:45:22 PM UTC+13, Erik wrote:
> Hi Callum,
> 
> On 04/01/17 00:30, Callum Robinson wrote:
> > I feel like im missing something so blatantly obvious.
> 
> That's because you are ;). I don't want to come across as patronising, 
> but I want you to see it for yourself, so, here's a function definition 
> similar to yours that doesn't have the same syntax error that yours does:
> 
> def foo(spam, ham):
>      if spam == ham:
>          return "same"
>      return "different"
> 
> See the difference?
> 
> E.

I've figured out that out but I have a new issue. I like what you are doing making me figure this out as it helps me remember. I'll post the new code and the issue. If you could give me a hint that would be great. 

------------------------------------------
Issue
------------------------------------------

Traceback (most recent call last):
  File "D:/Python/random.py", line 6, in <module>
    computer_number = number.randint(1, 100)
NameError: name 'number' is not defined


-----------------------------------------
Here is the most recent code
-----------------------------------------


# mynumber.py
# this game uses a home made function
import random

#think of a number
computer_number = number.randint(1, 100)

#create the function is_same()
def is_same(target, number):
        if target == number:
            result="Win"
        elif target > number:
            result="Low"
        else:
            result="High"
        return result

# start the game
print("hello. \nI have thought of a number between 1 and 100.")

#collect the user's guess as an interger
guess = int(input("Can you guess it? "))
#Use our function
higher_or_lower = is_same(computer_number, guess)
#run the game untill the user is correct
while higher_or_lower != "win":
    if higher_or_lower == "low":
         guess = int(input("Sorry, you are too low. Try again."))
    else:
        guess = int(input("Sorry your are too high. Try again."))

    higher_or_lower = is_same(computer_number, guess)

#end of game
input("Correct!\nWell Done\n\n\nPress RETURN to exit.")
            
            
            



From tjreedy at udel.edu  Tue Jan  3 20:06:18 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Tue, 3 Jan 2017 20:06:18 -0500
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <de17ea17-a783-4b03-bdd6-7ac5afa63c51@googlegroups.com>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <de17ea17-a783-4b03-bdd6-7ac5afa63c51@googlegroups.com>
Message-ID: <o4hhq6$3d6$1@blaine.gmane.org>

On 1/3/2017 7:02 PM, Callum Robinson wrote:
> When i check the code it comes up with invalid syntax and my writing line gets re directed here
>
> def is_same(target, number:
>         if target == number:
>             result="win"
>         elif target > number:
>             result="low"
>         else:
>             result="high"
>         return result

When I paste this into a file in IDLE and try to run the file, 'if' is 
highlighted in red.  This means that there is an error somewhere at or 
before the 'if'.


-- 
Terry Jan Reedy



From steve+python at pearwood.info  Tue Jan  3 20:10:01 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 12:10:01 +1100
Subject: How Best to Coerce Python Objects to Integers?
References: <3d35c052-a4c2-44f9-b294-cb1a77d77477@googlegroups.com>
 <586C28EC.8010607@stoneleaf.us>
 <CAPTjJmrm5a5dMGQLPev9A+DLdJP0z5wEmsN=C5CiaYu8-mB=kg@mail.gmail.com>
 <8e7195db-e33f-18e3-e1d9-74f9a458e69b@lucidity.plus.com>
 <mailman.185.1483489341.2395.python-list@python.org>
Message-ID: <586c4b6b$0$1612$c3e8da3$5496439d@news.astraweb.com>

On Wed, 4 Jan 2017 11:22 am, Erik wrote:

> On 03/01/17 22:47, Chris Angelico wrote:
>> On Wed, Jan 4, 2017 at 9:42 AM, Ethan Furman <ethan at stoneleaf.us> wrote:
>>> Aside from calling "except Exception" a "naked except"
>>
>> If you read the comments, you'll see that he originally had an actual
>> bare except clause, but then improved the code somewhat in response to
>> a recommendation that SystemExit etc not be caught.
> 
> But, as stated at the top of the article, his brief was: "The strings
> come from a file that a human has typed in, so even though most of the
> values are good, a few will have errors ('25C') that int() will reject.".

Right. And from there he starts worrying about the case where the inputs
aren't strings at all, or they're weird exotic objects with nasty __int__
methods. That's overkill and can only hide programming errors.


> What he *should* have done is just validated his input strings before
> presenting the string to int() - i.e., process the input with knowledge
> that is specific to the problem domain before calling the
> general-purpose function.

That's the Look Before You Leap solution. But in this case, given the
scenario described (a text file with a few typos), the best way is to ask
for forgiveness rather than permission:

def int_or_else(value):
    try:
        return int(value)
    else ValueError:
        pass


Why is this better? In the given scenario, errors are rare. Most values are
good, with only a few typos, so it is wasteful to parse the string twice,
once to validate it and once to generate the int. Besides, there's probably
no Python code you can write which will validate an int as fast as the
int() function itself.


[...]
> Instead, he tried to patch around int() rejecting the strings. And then
> decided that he'd patch around int() rejecting things that weren't even
> strings even though that's not what the function has (apparently) been
> specified to receive.

Indeed.


Another thought: if he is receiving human generated input, there is an
argument to be made for accepting "look alikes" -- e.g. maybe the data was
entered by Aunt Tilly, who was a typist in the 1960s and can't break the
habit of using l or I interchangeably for 1, and O for 0.




-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From cs at zip.com.au  Tue Jan  3 20:10:30 2017
From: cs at zip.com.au (Cameron Simpson)
Date: Wed, 4 Jan 2017 12:10:30 +1100
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <586b0517$0$1584$c3e8da3$5496439d@news.astraweb.com>
References: <586b0517$0$1584$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <20170104011030.GA46099@cskk.homeip.net>

On 03Jan2017 12:57, Steve D'Aprano <steve+python at pearwood.info> wrote:
>I dislike the Unix-style Vim/Emacs text editors, I prefer a traditional
>GUI-based editor. So my "IDE" is:
>- Firefox, for doing searches and looking up documentation;
>- an GUI programmer's editor, preferably one with a tab-based
>  interface, such as geany or kate;
>- a tab-based terminal.

"traditional GUI-based editor"

For those of us who spent a lot of our earlier time on terminals (actual 
physical terminals) we consider GUIs "new fangled".

Just narking,
Cameron Simpson <cs at zip.com.au>


From python at deborahswanson.net  Tue Jan  3 20:12:22 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 17:12:22 -0800
Subject: Screwing Up looping in Generator
In-Reply-To: <8feb9bc0-cc89-97d6-589a-fe9b1072ff88@lucidity.plus.com>
Message-ID: <009201d26627$9aee9390$27b23dae@sambora>

Erik wrote, on January 03, 2017 3:53 PM
> 
> On 03/01/17 23:05, Deborah Swanson wrote:
> > And yes, we usually used for loops for generators, unless you don't 
> > know when the generator will be exhausted. As in this case, 
> where the 
> > number of files the generator can provide is unknown. Then 
> we used the 
> > while True, break on StopIteration method.
> 
> Out of interest, *why* was it deemed necessary to do 
> something different 
> if you don't know how many items the generator will generate? Was any 
> rationale given for that?
> 
> for x in foo:
>    bar(x)
> 
> ... where foo is any iterable (something that has a __iter__ method 
> defined - including generators) will just bind each value in 
> turn to 'x' 
> and will exit when the StopIteration exception is raised under the 
> covers by the iterator that is iterating over the iterable.
> 
> Some generators are infinite (and their iterator will never raise a 
> StopIteration exception).
> 
> E.

The main reason you might want to catch the StopIteration exception is
to do something else before your code simply stops running. If all
you're doing is run a generator til it's out of gas, and that's all you
want it to do, then there's no need to catch anything. There's lots of
situations where this is exactly what you want. It might even be the
most frequent use of generators, though I wouldn't know. 



From steve+python at pearwood.info  Tue Jan  3 20:15:57 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 12:15:57 +1100
Subject: Hey, I'm new to python so don't judge.
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <de17ea17-a783-4b03-bdd6-7ac5afa63c51@googlegroups.com>
 <aaaddf7e-8835-4860-7338-69fc55376fbe@lucidity.plus.com>
 <mailman.186.1483489577.2395.python-list@python.org>
 <5e69d496-f5d3-4aab-ae78-3d1d57d3aee4@googlegroups.com>
 <71b9f7e5-c255-435f-e7d6-3cc7abce35b4@lucidity.plus.com>
 <mailman.187.1483490711.2395.python-list@python.org>
 <3021b6e8-d843-413f-a62b-f51461ed1b49@googlegroups.com>
Message-ID: <586c4ccf$0$1602$c3e8da3$5496439d@news.astraweb.com>

On Wed, 4 Jan 2017 12:04 pm, Callum Robinson wrote:

> Traceback (most recent call last):
>   File "D:/Python/random.py", line 6, in <module>
>     computer_number = number.randint(1, 100)
> NameError: name 'number' is not defined


That's exactly what we need to see! The full traceback, thank you!

You're asking Python to get the variable "number", and call the randint
method. But:

- you don't have a variable called "number";

NameError: name 'number' is not defined


- and even if you did, that's not how you get a random number. What you want
is:

computer_number = random.randint(1, 100)






-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From cs at zip.com.au  Tue Jan  3 20:20:18 2017
From: cs at zip.com.au (Cameron Simpson)
Date: Wed, 4 Jan 2017 12:20:18 +1100
Subject: trouble with cmd.Cmd and prompting
In-Reply-To: <o4ghl4$ejg$1@blaine.gmane.org>
References: <o4ghl4$ejg$1@blaine.gmane.org>
Message-ID: <20170104012018.GA72609@cskk.homeip.net>

On 03Jan2017 16:57, Peter Otten <__peter__ at web.de> wrote:
>Cameron Simpson wrote:
>> On 03Jan2017 00:14, Dennis Lee Bieber <wlfraed at ix.netcom.com> wrote:
>>>On Tue, 3 Jan 2017 11:33:15 +1100, Cameron Simpson <cs at zip.com.au>
>>>declaimed the following:
>>>>I'm using cmd.Cmd to write a little FTP-like command line to interface to
>>>>a storage system of mine and encountering weird behaviour. When I enter a
>>>>command the next prompt appears _before_ the associated operation runs,
[...]
>>>Haven't used the module but there is something I find intriguing in the
>>>help system
>>>-=-=-=-=-
>>> Cmd.precmd(line)
>>>    Hook method executed just before the command line is interpreted, but
>>>after the input prompt is generated and issued.
>>>-=-=-=-=-
>>>"... AFTER the input prompt is ... issued"
[...]
>I don't believe Dennis' reading of the docs is correct, and the relevant
>part of the source (Python 3.4) does not show anything to support it:
[... code that runs as I had imagined ...]
>Is there something asynchronous in your command? Perhaps you can post a
>minimal runnable example that shows the odd behaviour.

In the commands themselves? No, but the storage system has lots of asynchronous 
activity.

I'm bothered by the fact that an empty command also shows this behaviour.

I will try to get a minimal example others can run.

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


From torriem at gmail.com  Tue Jan  3 20:22:59 2017
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 3 Jan 2017 18:22:59 -0700
Subject: Clickable hyperlinks
In-Reply-To: <007b01d26619$97de4eb0$27b23dae@sambora>
References: <007b01d26619$97de4eb0$27b23dae@sambora>
Message-ID: <cf1ab04a-5e85-038c-9712-78b0abaef4b5@gmail.com>

On 01/03/2017 04:32 PM, Deborah Swanson wrote:
> The GUI consoles I have are in Pycharm, the IDLE that comes with
> Anaconda, and Spyder. PyCharm and IDLE both ask for internet access when
> I open them, so they're capable of opening links, but whether that means
> their output space is capable of handling clickable links I don't know.

Hmm I still don't understand what you mean by "GUI console."  Just
because a program asks for internet access does not mean anything about
whether or not your python program can display a clickable link in a
console window.  Besides that, a clickable link would probably ask the
OS to open it with the default application, not cause your program to
access the internet.

The standard out pipe (where stuff goes when you call print() or write
to sys.stdout) from a python program usually goes to a console or a
terminal emulator.  PyCharm and IDLE both provide windows to display
this output (they emulate a terminal). But maybe you're misunderstanding
what this actually is.  These windows just display a stream of bytes
that come out of your program.  Certain escape codes can be emitted that
can instruct the console or terminal emulator to do things like set text
color or display text at a certain position. But there's certainly no
special way to instruct the terminal emulator to make a section of text
into a hyperlink.  Maybe if hyperlinks had existed years ago when
terminal escape codes were being defined we'd have a "hyperlink" code
that all consoles and terminals would understand.  A few years ago I saw
some proposals to add an escape code to the ANSI scheme that would
encode hyperlinks, but nothing ever came of it because, honestly, it
would be too much hassle to roll this out to ever terminal emulator out
there (to say nothing of real terminals).

> I do know printing a full url with the %s specifier or entering a url
> and clicking enter just gives you the plain text url. Obviously, not all
> GUI consoles are enabled recognize and make clickable links from
> correctly formatted urls.

On my Linux machine, the terminal emulators I've used all make a regular
url printed out into a clickable link (or at least a right-clickable
link).  This is just something they try to do with all things that look
like urls.  Sometimes it's helpful, often it's annoying.

> I was hoping there was some functionality in python to make clickable
> links. Could be a package, if the core language doesn't have it.

No, there is not.  If you made a full GUI app using a toolkit like GTK
or Qt, you can indeed place hyperlinks on your forms and the operating
system will automatically connect them to the web browser.  But not in
text-mode terminal apps.



From cr2001 at hotmail.co.nz  Tue Jan  3 20:25:13 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 3 Jan 2017 17:25:13 -0800 (PST)
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <586c4ccf$0$1602$c3e8da3$5496439d@news.astraweb.com>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <de17ea17-a783-4b03-bdd6-7ac5afa63c51@googlegroups.com>
 <aaaddf7e-8835-4860-7338-69fc55376fbe@lucidity.plus.com>
 <mailman.186.1483489577.2395.python-list@python.org>
 <5e69d496-f5d3-4aab-ae78-3d1d57d3aee4@googlegroups.com>
 <71b9f7e5-c255-435f-e7d6-3cc7abce35b4@lucidity.plus.com>
 <mailman.187.1483490711.2395.python-list@python.org>
 <3021b6e8-d843-413f-a62b-f51461ed1b49@googlegroups.com>
 <586c4ccf$0$1602$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <b87802f8-116c-4e8e-b7b4-61cfb1c3af60@googlegroups.com>

On Wednesday, January 4, 2017 at 2:16:08 PM UTC+13, Steve D'Aprano wrote:
> On Wed, 4 Jan 2017 12:04 pm, Callum Robinson wrote:
> 
> > Traceback (most recent call last):
> >   File "D:/Python/random.py", line 6, in <module>
> >     computer_number = number.randint(1, 100)
> > NameError: name 'number' is not defined
> 
> 
> That's exactly what we need to see! The full traceback, thank you!
> 
> You're asking Python to get the variable "number", and call the randint
> method. But:
> 
> - you don't have a variable called "number";
> 
> NameError: name 'number' is not defined
> 
> 
> - and even if you did, that's not how you get a random number. What you want
> is:
> 
> computer_number = random.randint(1, 100)
> 
> 
> 
> 
> 
> 
> -- 
> Steve
> ?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
> enough, things got worse.

Hey man thanks, the sad thing is i have no idea why i put that in. I must be having a terrible day.


From python at lucidity.plus.com  Tue Jan  3 20:25:38 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 4 Jan 2017 01:25:38 +0000
Subject: Screwing Up looping in Generator
In-Reply-To: <009201d26627$9aee9390$27b23dae@sambora>
References: <009201d26627$9aee9390$27b23dae@sambora>
Message-ID: <aa968655-9d16-b02f-bd7f-31ad8dc7d651@lucidity.plus.com>

Hi,

On 04/01/17 01:12, Deborah Swanson wrote:
> The main reason you might want to catch the StopIteration exception is
> to do something else before your code simply stops running. If all
> you're doing is run a generator til it's out of gas, and that's all you
> want it to do, then there's no need to catch anything.

Ah! OK, I see where the lines are being crossed now ;) Although 
StopIteration is an exception, it is something that the 'for/iter' 
machinery handles for you under the covers. Each 'for' statement 
effectively has a 'try' block around it that catches 'StopIteration' and 
just terminates that particular 'for' loop and continues on with the 
remainder of your script.

Raising a 'StopIteration' is an internal mechanism used to determine 
when an iterator (i.e., the thing a 'for' loop is looping over) has 
exhausted itself. It's not something a regular user is ever expected to 
know about let alone catch.

When execution falls out of the bottom of a generator, StopIteration is 
raise (compared to a regular function or method returning 'None').

E.


From flebber.crue at gmail.com  Tue Jan  3 20:35:59 2017
From: flebber.crue at gmail.com (Sayth Renshaw)
Date: Tue, 3 Jan 2017 17:35:59 -0800 (PST)
Subject: Screwing Up looping in Generator
In-Reply-To: <mailman.195.1483493141.2395.python-list@python.org>
References: <009201d26627$9aee9390$27b23dae@sambora>
 <aa968655-9d16-b02f-bd7f-31ad8dc7d651@lucidity.plus.com>
 <mailman.195.1483493141.2395.python-list@python.org>
Message-ID: <dc1a0766-2305-4c56-a0c0-d8418f9b0a02@googlegroups.com>

So can I call the generator twice and receive the same file twice in 2 for loops?

Once to get the files name and the second to process?

 for file in rootobs: 
        base = os.path.basename(file.name) 
        write_to = os.path.join("output", os.path.splitext(base)[0] + ".csv") 
        with open(write_to, 'w', newline='') as csvf: 
            for file in rootobs:
              # create and write csv

Cheers

Sayth


From bouncingcats at gmail.com  Tue Jan  3 20:36:00 2017
From: bouncingcats at gmail.com (David)
Date: Wed, 04 Jan 2017 13:36:00 +1200
Subject: Clickable hyperlinks
Message-ID: <309467853@f38.n261.z1.binkp.net>

On 4 January 2017 at 11:50, Deborah Swanson <python at deborahswanson.net> wrote:
> Erik wrote, on January 03, 2017 3:30 PM
>>
>> When you start a new topic on the list, could you please write a new
>> message rather than replying to an existing message and changing the
>> title/subject?
>>
> Certainly. I've been on many other lists before (but none since about
> 2011), and no one complained of or even mentioned this problem. But if
> it's a problem with some email readers now, I can easily just start a
> new message.  Just being lazy and following old habits, I guess. ;)

To be clear, the problem is not "with some email readers".

The problem is that it breaks the thread management features that are built 
into every email message, making it impossible to display threads correctly.

As can be seen here for example:
https://mail.python.org/pipermail/python-list/2017-January/thread.html

Note how most threads start in the leftmost column and replies are indented. 
But this does not occur where you began the new subject: "Clickable 
hyperlinks".

Thanks.



From cr2001 at hotmail.co.nz  Tue Jan  3 20:37:24 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 3 Jan 2017 17:37:24 -0800 (PST)
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
Message-ID: <26855fa4-dc40-43ae-9eaa-15dc1de97842@googlegroups.com>

On Wednesday, January 4, 2017 at 12:49:28 PM UTC+13, Callum Robinson wrote:
> Im doing a new task from my teacher but i can't seem to find what is wrong with this code. Can anyone help?
> 
> #mynumber.py
> # this game uses a home made function
> import random
> 
> #think of a number
> computer_number = number.randint(1,100)
> 
> #create the function is_same()
> def is_same(target, number:
>         if target == number:
>             result="win"
>         elif target > number:
>             result="low"
>         else:
>             result="high"
>         return result
> 
> # start the game
> print("hello. \nI have thought of a number between 1 and 100.")
> 
> #collect the user's guess as an interger
> guess = int(input("Can you guess it? "))
> #Use our function
> higher_or_lower = is_same(computer_number, guess)
> #run the game untill the user is correct
> while higher_or_lower != "win"
>     if higher_or_lower == "to low"
>          guess = int(input("Sorry, you are too low. Try again."))
>     else:
>         guess = int(input("Sorry your are too high. Try again."))
> 
>     higher_or_lower = is_same(computer_number, guess)
> 
> #end of game
> input("Correct!\nWell Done\n\n\nPress RETURN to exit.")

Hey again, i'm sorry for bothering you with so many questions i just did not want to keep asking my teacher who is on holiday these.

I have another issue where the code runs but i can guess every number from 1-100 but it always says Sorry your are too high. Try again. I don't understand what i have done to cause this.


From steve+comp.lang.python at pearwood.info  Tue Jan  3 20:43:46 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 04 Jan 2017 13:43:46 +1200
Subject: Clickable hyperlinks
References: <973176847@f38.n261.z1.binkp.net>
Message-ID: <4238055976@f38.n261.z1.binkp.net>

On Wednesday 04 January 2017 15:46, Deborah Swanson wrote:

> Steven D'Aprano wrote, on January 03, 2017 8:04 PM
[...]
>> Of course you have to put quotes around them to enter them in
>> your source code.
>> We don't expect this to work:
>>
>>     print(Hello World!)
>>
>>
>> you have to use a string literal with quotes:
>>
>>     print('Hello World!')
>>
>>
>> Same for all of the above.

> I didn't try printing them before, but I just did. Got:
>
>>>> print([Example](http://www.example.com)
>
> SyntaxError: invalid syntax  (arrow pointing at the colon)

You missed the part where I said you have to put them in quotes.

Like any other string in Python, you have to use quotation marks around it for 
Python to understand it as a string. None of these things will work:

print( Hello World! )

print( What do you want to do today? )

print( 3 2 1 blast off )

print( http://www.example.com )


This isn't specific to print. This won't work either:

message = Hello World!

In *all* of these cases, you have to tell Python you're dealing with a string, 
and you do that with quotation marks:

message = "Hello World!"
print( 'What do you want to do today?' ) count_down = '3 2 1 blast off'
url = 'http://www.example.com'




--
Steven
"Ever since I learned about confirmation bias, I've been seeing it everywhere." 
- Jon Ronson



From rhodri at kynesim.co.uk  Tue Jan  3 20:47:14 2017
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Wed, 04 Jan 2017 13:47:14 +1200
Subject: Screwing Up looping in Generator
Message-ID: <2751329663@f38.n261.z1.binkp.net>

On 04/01/17 02:10, Deborah Swanson wrote:
> Sayth Renshaw wrote, on January 03, 2017 5:36 PM
>>
>> So can I call the generator twice and receive the same file
>> twice in 2 for loops?
>>
>> Once to get the files name and the second to process?
>>
>>  for file in rootobs:
>>         base = os.path.basename(file.name)
>>         write_to = os.path.join("output",
>> os.path.splitext(base)[0] + ".csv")
>>         with open(write_to, 'w', newline='') as csvf:
>>             for file in rootobs:
>>               # create and write csv
>>
>> Cheers
>>
>> Sayth
>
> I don't see why not, if you let the first one run to completion and then
> do it again a second time. Assuming your generator doesn't somehow
> delete or modify the file specifications as it yields them. It would be
> helpful to see the code for rootobs, if you have it.

Ahem.  If Sayth is using the correct terminology and rootobs actually is a 
generator (not, say, a list or tuple), then no it won't work.  Once a generator 
is exhausted, it's exhausted.  Besides, the nested for-loops over the same 
iterable is a dead giveaway that something is wrong.


--
Rhodri James *-* Kynesim Ltd



From flebber.crue at gmail.com  Tue Jan  3 20:54:34 2017
From: flebber.crue at gmail.com (Sayth Renshaw)
Date: Tue, 3 Jan 2017 17:54:34 -0800 (PST)
Subject: Screwing Up looping in Generator
In-Reply-To: <dc1a0766-2305-4c56-a0c0-d8418f9b0a02@googlegroups.com>
References: <009201d26627$9aee9390$27b23dae@sambora>
 <aa968655-9d16-b02f-bd7f-31ad8dc7d651@lucidity.plus.com>
 <mailman.195.1483493141.2395.python-list@python.org>
 <dc1a0766-2305-4c56-a0c0-d8418f9b0a02@googlegroups.com>
Message-ID: <1e433232-7db7-4f1c-8637-50a3da469b20@googlegroups.com>

On Wednesday, 4 January 2017 12:36:10 UTC+11, Sayth Renshaw  wrote:
> So can I call the generator twice and receive the same file twice in 2 for loops?
> 
> Once to get the files name and the second to process?
> 
>  for file in rootobs: 
>         base = os.path.basename(file.name) 
>         write_to = os.path.join("output", os.path.splitext(base)[0] + ".csv") 
>         with open(write_to, 'w', newline='') as csvf: 
>             for file in rootobs:
>               # create and write csv
> 
> Cheers
> 
> Sayth

I just need it to write after each file however the 

with open(#file) as csvf:

Keeps it all open until every file processed in an output file with the name of the first file in the generator.

Sayth


From python at deborahswanson.net  Tue Jan  3 21:05:13 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 18:05:13 -0800
Subject: Screwing Up looping in Generator
In-Reply-To: <CAPTjJmoTehb94xKfgUAPsYw5Sd54SxtMT5t-pi1f35vTCFLJxg@mail.gmail.com>
Message-ID: <009d01d2662e$fd3a4970$27b23dae@sambora>

Chris Angelico wrote, on January 03, 2017 3:35 PM
> 
> On Wed, Jan 4, 2017 at 10:05 AM, Deborah Swanson 
> <python at deborahswanson.net> wrote:
> > Ok, I learned how to use generators in Python 2.7.8, which may be 
> > different from Python 3 for generators. But I learned from MIT's 
> > online introduction to python course, and they certainly 
> seem to know 
> > python well. So what is the correct way to call the 
> generator's next 
> > yield in Python 3? We only learned to use the next function. If you 
> > don't use the next function, what do you use?
> 
> The built-in next function, not the next method.
> 
> # don't do this
> gen.next()
> 
> # do this
> next(gen)
> 
> ChrisA

You speak the truth! I never doubted, but since I still have 2.7.8 on my
system  I decided to try it out.

For a simple little Fibbonacci number generator:

def genFib (): 
        fibn_1 = 1 #fib(n-1) 
        fibn_2 = 0 #fib(n-2) 
        while True: 
                # fib(n) = fib(n-1) + fib(n-2) 
                next = fibn_1 + fibn_2 
                yield next 
                fibn_2 = fibn_1 
                fibn_1 = next

and at the console:

>>> fib = genFib()
>>> fib.next()

2.7.8 works, and cranks out as many Fibbonacci numbers as you could
want.

But in 3.4.3 you get:

Traceback (most recent call last):
  File "<pyshell#13>", line 1, in <module>
    fib.next()
AttributeError: 'generator' object has no attribute 'next'

Then, going the other way, next(fib) works in both versions.  




From python at mrabarnett.plus.com  Tue Jan  3 21:05:35 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Wed, 4 Jan 2017 02:05:35 +0000
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <26855fa4-dc40-43ae-9eaa-15dc1de97842@googlegroups.com>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <26855fa4-dc40-43ae-9eaa-15dc1de97842@googlegroups.com>
Message-ID: <07f87e48-6bb3-ad25-6f4f-7d350c5b794a@mrabarnett.plus.com>

On 2017-01-04 01:37, Callum Robinson wrote:
> On Wednesday, January 4, 2017 at 12:49:28 PM UTC+13, Callum Robinson wrote:
>> Im doing a new task from my teacher but i can't seem to find what is wrong with this code. Can anyone help?
>>
>> #mynumber.py
>> # this game uses a home made function
>> import random
>>
>> #think of a number
>> computer_number = number.randint(1,100)
>>
>> #create the function is_same()
>> def is_same(target, number:
>>         if target == number:
>>             result="win"
>>         elif target > number:
>>             result="low"
>>         else:
>>             result="high"
>>         return result
>>
>> # start the game
>> print("hello. \nI have thought of a number between 1 and 100.")
>>
>> #collect the user's guess as an interger
>> guess = int(input("Can you guess it? "))
>> #Use our function
>> higher_or_lower = is_same(computer_number, guess)
>> #run the game untill the user is correct
>> while higher_or_lower != "win"
>>     if higher_or_lower == "to low"
>>          guess = int(input("Sorry, you are too low. Try again."))
>>     else:
>>         guess = int(input("Sorry your are too high. Try again."))
>>
>>     higher_or_lower = is_same(computer_number, guess)
>>
>> #end of game
>> input("Correct!\nWell Done\n\n\nPress RETURN to exit.")
>
> Hey again, i'm sorry for bothering you with so many questions i just did not want to keep asking my teacher who is on holiday these.
>
> I have another issue where the code runs but i can guess every number from 1-100 but it always says Sorry your are too high. Try again. I don't understand what i have done to cause this.
>
What values can 'is_same' return?

Which of those values are you checking for in the loop?



From flebber.crue at gmail.com  Tue Jan  3 21:09:35 2017
From: flebber.crue at gmail.com (Sayth Renshaw)
Date: Tue, 3 Jan 2017 18:09:35 -0800 (PST)
Subject: Screwing Up looping in Generator
In-Reply-To: <1e433232-7db7-4f1c-8637-50a3da469b20@googlegroups.com>
References: <009201d26627$9aee9390$27b23dae@sambora>
 <aa968655-9d16-b02f-bd7f-31ad8dc7d651@lucidity.plus.com>
 <mailman.195.1483493141.2395.python-list@python.org>
 <dc1a0766-2305-4c56-a0c0-d8418f9b0a02@googlegroups.com>
 <1e433232-7db7-4f1c-8637-50a3da469b20@googlegroups.com>
Message-ID: <08c82541-86f7-4811-abeb-1205d2064506@googlegroups.com>

Untested as i wrote this in notepad at work but, if i first use the generator to create a set of filenames and then iterate it then call the generator anew to process file may work?

Good idea or better available?

def get_list_of_names(generator_arg):
    name_set = set()
    for name in generator_arg:
        base = os.path.basename(name.name)
        filename = os.path.splitext(base)[0]
        name_set.add(filename)
    return name_set



 for file_name in name_set: 
     directory = "output"
         with open(os.path.join(directory, filename, 'w', newline='') as csvf: 
            for file in rootobs: 
              # create and write csv 

Sayth


From python at lucidity.plus.com  Tue Jan  3 21:09:40 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 4 Jan 2017 02:09:40 +0000
Subject: How Best to Coerce Python Objects to Integers?
In-Reply-To: <586c4b6b$0$1612$c3e8da3$5496439d@news.astraweb.com>
References: <3d35c052-a4c2-44f9-b294-cb1a77d77477@googlegroups.com>
 <586C28EC.8010607@stoneleaf.us>
 <CAPTjJmrm5a5dMGQLPev9A+DLdJP0z5wEmsN=C5CiaYu8-mB=kg@mail.gmail.com>
 <8e7195db-e33f-18e3-e1d9-74f9a458e69b@lucidity.plus.com>
 <mailman.185.1483489341.2395.python-list@python.org>
 <586c4b6b$0$1612$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <ecc5e4fa-b8a6-282c-6b1c-37943fcda6a4@lucidity.plus.com>

On 04/01/17 01:10, Steve D'Aprano wrote:
> On Wed, 4 Jan 2017 11:22 am, Erik wrote:
>> What he *should* have done is just validated his input strings before
>> presenting the string to int() - i.e., process the input with knowledge
>> that is specific to the problem domain before calling the
>> general-purpose function.
>
> That's the Look Before You Leap solution. But in this case, given the
> scenario described (a text file with a few typos), the best way is to ask
> for forgiveness rather than permission:

Yes, probably, in this case ;)

OK, in the case where the function you're calling is sane (and Python's 
int() is - it won't blindly accept "0x101" as a hex value, for example) 
then it's probably right that leaping first and then, on failure, 
processing the value and leaping again is the right thing to do.

[I tend to work in an environment where things I'm calling may not be 
sane (and in some cases I may never know), so I will usually consider 
LBYL as a way of CMA ;)].

In this whole discussion there has been no mention of what happens when 
the function returns None, though.

> Another thought: if he is receiving human generated input, there is an
> argument to be made for accepting "look alikes" -- e.g. maybe the data was
> entered by Aunt Tilly, who was a typist in the 1960s and can't break the
> habit of using l or I interchangeably for 1, and O for 0.

Sure - and that's what I meant by processing the string according to his 
problem "domain". If he has Aunt Tillys doing his data input, then l->1 
and 0->O may be a reasonable thing (I recently did a project where 
things like converting Icelandic's Eth and Thorn runic letters to 'D' 
and 'P' - though morally wrong ;) - was a reasonable character 
translation because that's what people actually typed in).

E.


From python at deborahswanson.net  Tue Jan  3 21:10:16 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 18:10:16 -0800
Subject: Screwing Up looping in Generator
In-Reply-To: <dc1a0766-2305-4c56-a0c0-d8418f9b0a02@googlegroups.com>
Message-ID: <009e01d2662f$b1bf0e30$27b23dae@sambora>

Sayth Renshaw wrote, on January 03, 2017 5:36 PM
> 
> So can I call the generator twice and receive the same file 
> twice in 2 for loops?
> 
> Once to get the files name and the second to process?
> 
>  for file in rootobs: 
>         base = os.path.basename(file.name) 
>         write_to = os.path.join("output", 
> os.path.splitext(base)[0] + ".csv") 
>         with open(write_to, 'w', newline='') as csvf: 
>             for file in rootobs:
>               # create and write csv
> 
> Cheers
> 
> Sayth

I don't see why not, if you let the first one run to completion and then
do it again a second time. Assuming your generator doesn't somehow
delete or modify the file specifications as it yields them. It would be
helpful to see the code for rootobs, if you have it.
D.



From zxpatric at gmail.com  Tue Jan  3 21:14:10 2017
From: zxpatric at gmail.com (zxpatric)
Date: Wed, 04 Jan 2017 14:14:10 +1200
Subject: Work between multiple processes
Message-ID: <2510477911@f38.n261.z1.binkp.net>

Hi everyone,

I ran into a case that I need to create a work process of an application 
(Jython so has to call using java.exe) which will collect the data based on 
what main process indicates.

(1) I tried multiprocessing package, no luck. Java.exe can't be called from 
Process class?

(2) I tried subprocess. subprocess.communicate function will wait for the work 
process to terminate so to return.


either (1) or (2) doesn't work out well. Please suggest.  Global system queue?

Thanks,
Patrick.



From steve+comp.lang.python at pearwood.info  Tue Jan  3 21:16:58 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 04 Jan 2017 14:16:58 +1200
Subject: Hey, I'm new to python so don't judge.
References: <802561195@f38.n261.z1.binkp.net>
Message-ID: <1096384302@f38.n261.z1.binkp.net>

On Wednesday 04 January 2017 13:24, Callum Robinson wrote:

> On Wednesday, January 4, 2017 at 3:05:48 PM UTC+13, MRAB wrote:
>> On 2017-01-04 01:37, Callum Robinson wrote:
>> > On Wednesday, January 4, 2017 at 12:49:28 PM UTC+13, Callum Robinson
>> > wrote:
>> >> Im doing a new task from my teacher but i can't seem to find what is
>> >> wrong with this code. Can anyone help?
>> >>
>> >> #mynumber.py
>> >> # this game uses a home made function
>> >> import random
>> >>
>> >> #think of a number
>> >> computer_number = number.randint(1,100)
>> >>
>> >> #create the function is_same()
>> >> def is_same(target, number:
>> >>         if target == number:
>> >>             result="win"
>> >>         elif target > number:
>> >>             result="low"
>> >>         else:
>> >>             result="high"
>> >>         return result
>> >>
>> >> # start the game
>> >> print("hello. \nI have thought of a number between 1 and 100.")
>> >>
>> >> #collect the user's guess as an interger
>> >> guess = int(input("Can you guess it? "))
>> >> #Use our function
>> >> higher_or_lower = is_same(computer_number, guess)
>> >> #run the game untill the user is correct
>> >> while higher_or_lower != "win"
>> >>     if higher_or_lower == "to low"
>> >>          guess = int(input("Sorry, you are too low. Try again."))
>> >>     else:
>> >>         guess = int(input("Sorry your are too high. Try again."))
>> >>
>> >>     higher_or_lower = is_same(computer_number, guess)
>> >>
>> >> #end of game
>> >> input("Correct!\nWell Done\n\n\nPress RETURN to exit.")
>> >
>> > Hey again, i'm sorry for bothering you with so many questions i just did
>> > not want to keep asking my teacher who is on holiday these.
>> >
>> > I have another issue where the code runs but i can guess every number from
>> > 1-100 but it always says Sorry your are too high. Try again. I don't
>> > understand what i have done to cause this.
>> >
>> What values can 'is_same' return?
>>
>> Which of those values are you checking for in the loop?
>
> I'm sorry but i do not completely understand what you are stating

That's okay, you're still learning :-)

We've all been where you are, even if some of us have forgotten what its like.


Look at your is_same() function. It can return three different things, which 
gets stored in the higher_or_lower variable:

- "win"
- "low"
- "high"


But now look at how you check the result:

while higher_or_lower != "win"
    if higher_or_lower == "to low"
        guess = int(input("Sorry, you are too low. Try again."))
    else:
        guess = int(input("Sorry your are too high. Try again."))


I see a typo that will prevent your code from running: you are missing a colon 
after the first line, it should say:

while higher_or_lower != "win":

Likewise for the "if ..." line, it also needs to end with a colon.

So the first thing is that when asking for help, be *extra careful* that the 
code you show us is the same as the code you are actually running. (Otherwise 
we waste our time trying to debug code that you aren't even using!) You should 
always COPY AND PASTE your code, not retype it.

But let's assume that your actual code does include the needed colons, so it 
will run. What values do you check for?

- "to low"

and that's it. Look again at the values that higher_or_lower can actually be. 
Is there any way that higher_or_lower gets the value "to low"?

No. Remember that Python can't read your mind and realise that when you check 
for "to low", you actually mean just "low". So there is no way that the first 
if... clause will be triggered, so it always falls through to the else clause 
and prints "Sorry your are too high. Try again."

(P.S. you mean "Sorry you are too high", not "your are".)



--
Steven
"Ever since I learned about confirmation bias, I've been seeing it everywhere." 
- Jon Ronson



From python at deborahswanson.net  Tue Jan  3 21:21:59 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 18:21:59 -0800
Subject: Screwing Up looping in Generator
In-Reply-To: <1e433232-7db7-4f1c-8637-50a3da469b20@googlegroups.com>
Message-ID: <009f01d26631$544d04d0$27b23dae@sambora>

Sayth Renshaw wrote, on January 03, 2017 5:55 PM
> 
> On Wednesday, 4 January 2017 12:36:10 UTC+11, Sayth Renshaw  wrote:
> > So can I call the generator twice and receive the same file 
> twice in 2 
> > for loops?
> > 
> > Once to get the files name and the second to process?
> > 
> >  for file in rootobs: 
> >         base = os.path.basename(file.name) 
> >         write_to = os.path.join("output", 
> os.path.splitext(base)[0] + ".csv") 
> >         with open(write_to, 'w', newline='') as csvf: 
> >             for file in rootobs:
> >               # create and write csv
> > 
> > Cheers
> > 
> > Sayth
> 
> I just need it to write after each file however the 
> 
> with open(#file) as csvf:
> 
> Keeps it all open until every file processed in an output 
> file with the name of the first file in the generator.
> 

In that case, I think you just need to devise your output file name
scheme, and it looks like you want to use 'os.path.splitext(base)[0] +
".csv")'. Then  output each file in the same for loop, before you go
back for another input file. Just read in the file, do whatever you want
to it, and then write it to the new file name, all in the same loop.

I don't see any need to loop through rootobs a second time.




From cr2001 at hotmail.co.nz  Tue Jan  3 21:24:16 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 3 Jan 2017 18:24:16 -0800 (PST)
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <mailman.199.1483495538.2395.python-list@python.org>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <26855fa4-dc40-43ae-9eaa-15dc1de97842@googlegroups.com>
 <07f87e48-6bb3-ad25-6f4f-7d350c5b794a@mrabarnett.plus.com>
 <mailman.199.1483495538.2395.python-list@python.org>
Message-ID: <9a5a2843-4d4b-43de-b580-85889447e284@googlegroups.com>

On Wednesday, January 4, 2017 at 3:05:48 PM UTC+13, MRAB wrote:
> On 2017-01-04 01:37, Callum Robinson wrote:
> > On Wednesday, January 4, 2017 at 12:49:28 PM UTC+13, Callum Robinson wrote:
> >> Im doing a new task from my teacher but i can't seem to find what is wrong with this code. Can anyone help?
> >>
> >> #mynumber.py
> >> # this game uses a home made function
> >> import random
> >>
> >> #think of a number
> >> computer_number = number.randint(1,100)
> >>
> >> #create the function is_same()
> >> def is_same(target, number:
> >>         if target == number:
> >>             result="win"
> >>         elif target > number:
> >>             result="low"
> >>         else:
> >>             result="high"
> >>         return result
> >>
> >> # start the game
> >> print("hello. \nI have thought of a number between 1 and 100.")
> >>
> >> #collect the user's guess as an interger
> >> guess = int(input("Can you guess it? "))
> >> #Use our function
> >> higher_or_lower = is_same(computer_number, guess)
> >> #run the game untill the user is correct
> >> while higher_or_lower != "win"
> >>     if higher_or_lower == "to low"
> >>          guess = int(input("Sorry, you are too low. Try again."))
> >>     else:
> >>         guess = int(input("Sorry your are too high. Try again."))
> >>
> >>     higher_or_lower = is_same(computer_number, guess)
> >>
> >> #end of game
> >> input("Correct!\nWell Done\n\n\nPress RETURN to exit.")
> >
> > Hey again, i'm sorry for bothering you with so many questions i just did not want to keep asking my teacher who is on holiday these.
> >
> > I have another issue where the code runs but i can guess every number from 1-100 but it always says Sorry your are too high. Try again. I don't understand what i have done to cause this.
> >
> What values can 'is_same' return?
> 
> Which of those values are you checking for in the loop?

I'm sorry but i do not completely understand what you are stating


From steve+comp.lang.python at pearwood.info  Tue Jan  3 21:25:34 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 04 Jan 2017 14:25:34 +1200
Subject: Hey, I'm new to python so don't judge.
References: <637094488@f38.n261.z1.binkp.net>
Message-ID: <4159531582@f38.n261.z1.binkp.net>

On Wednesday 04 January 2017 12:25, Callum Robinson wrote:

> Hey man thanks, the sad thing is i have no idea why i put that in. I must be
> having a terrible day.

Don't worry about it. The difference between a beginner and an expert is *not* 
that experts make fewer mistakes, but that experts know how to fix those 
mistakes so quickly that they don't even notice them.

I know people who are seemingly incapable of typing more than three words in 
the row without two typos, but they manage to be excellent programmers. They'll 
typo some code:

    comptuer_number = number.radnint(1, 100)

try to run it, realise their mistake and fix it:

    comptuer_number = random.radnint(1, 100)


then run it again and realise there is at least one more mistake, and fix it:

    comptuer_number = random.randint(1, 100)


and then a third time:

    computer_number = random.randint(1, 100)


while a beginner is still puzzling over their first mistake. Don't stress about 
it, it is all just part of the learning process. All code starts off full of 
bugs.




--
Steven
"Ever since I learned about confirmation bias, I've been seeing it everywhere." 
- Jon Ronson



From python at lucidity.plus.com  Tue Jan  3 21:35:35 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 4 Jan 2017 02:35:35 +0000
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <9a5a2843-4d4b-43de-b580-85889447e284@googlegroups.com>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <26855fa4-dc40-43ae-9eaa-15dc1de97842@googlegroups.com>
 <07f87e48-6bb3-ad25-6f4f-7d350c5b794a@mrabarnett.plus.com>
 <mailman.199.1483495538.2395.python-list@python.org>
 <9a5a2843-4d4b-43de-b580-85889447e284@googlegroups.com>
Message-ID: <c6a382bd-8401-5814-c1ed-42b3d1cc8043@lucidity.plus.com>

On 04/01/17 02:24, Callum Robinson wrote:
> On Wednesday, January 4, 2017 at 3:05:48 PM UTC+13, MRAB wrote:
>> What values can 'is_same' return?
>>
>> Which of those values are you checking for in the loop?
>
> I'm sorry but i do not completely understand what you are stating

You need to think about the specific things (their type, their exact 
values) that your functions might return. Printing some trace output is 
a classic way of debugging your program. If, after this line:

 >>>> higher_or_lower = is_same(computer_number, guess)

... you added:

print (higher_or_lower)

... what values do you then see being output? How will those values be 
processed by the conditions you see that work on the "higher_or_lower" 
variable?

E.


From bouncingcats at gmail.com  Tue Jan  3 21:36:00 2017
From: bouncingcats at gmail.com (David)
Date: Wed, 4 Jan 2017 13:36:00 +1100
Subject: Clickable hyperlinks
In-Reply-To: <008e01d26624$7c84a7d0$27b23dae@sambora>
References: <4e756eb9-842b-98fe-3fa1-3b05baebe71a@lucidity.plus.com>
 <008e01d26624$7c84a7d0$27b23dae@sambora>
Message-ID: <CAMPXz=oMYFvasoOqAhFibnuy1sJGKfwRzcy7Uu3GzYofv5wtjA@mail.gmail.com>

On 4 January 2017 at 11:50, Deborah Swanson <python at deborahswanson.net> wrote:
> Erik wrote, on January 03, 2017 3:30 PM
>>
>> When you start a new topic on the list, could you please write a new
>> message rather than replying to an existing message and changing the
>> title/subject?
>>
> Certainly. I've been on many other lists before (but none since about
> 2011), and no one complained of or even mentioned this problem. But if
> it's a problem with some email readers now, I can easily just start a
> new message.  Just being lazy and following old habits, I guess. ;)

To be clear, the problem is not "with some email readers".

The problem is that it breaks the thread management features that are
built into every email message, making it impossible to display threads
correctly.

As can be seen here for example:
https://mail.python.org/pipermail/python-list/2017-January/thread.html

Note how most threads start in the leftmost column and replies are indented.
But this does not occur where you began the new subject: "Clickable hyperlinks".

Thanks.


From python at deborahswanson.net  Tue Jan  3 21:40:15 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 18:40:15 -0800
Subject: Screwing Up looping in Generator
In-Reply-To: <aa968655-9d16-b02f-bd7f-31ad8dc7d651@lucidity.plus.com>
Message-ID: <00a201d26633$e1ee6cf0$27b23dae@sambora>

Erik wrote, on January 03, 2017 5:26 PM
> Hi,
> 
> On 04/01/17 01:12, Deborah Swanson wrote:
> > The main reason you might want to catch the StopIteration 
> exception is 
> > to do something else before your code simply stops running. If all 
> > you're doing is run a generator til it's out of gas, and that's all 
> > you want it to do, then there's no need to catch anything.
> 
> Ah! OK, I see where the lines are being crossed now ;) Although 
> StopIteration is an exception, it is something that the 'for/iter' 
> machinery handles for you under the covers. Each 'for' statement 
> effectively has a 'try' block around it that catches 
> 'StopIteration' and 
> just terminates that particular 'for' loop and continues on with the 
> remainder of your script.
> 
> Raising a 'StopIteration' is an internal mechanism used to determine 
> when an iterator (i.e., the thing a 'for' loop is looping over) has 
> exhausted itself. It's not something a regular user is ever 
> expected to 
> know about let alone catch.
> 
> When execution falls out of the bottom of a generator, 
> StopIteration is 
> raise (compared to a regular function or method returning 'None').
> 
> E.

Looks like those MIT professors knew what they were teaching us after
all! Sneaky, but they never once hinted that this was any deep dark
secret. Just a way to deal with generators that will stop after a finite
and unknown number of yields, and you want your code to keep going after
the generator quits. I thought I was just regurgitating a standard
approach, and surprised to get so much push back on it. 

Seems like python uses a lot of its external functionality (what we
normally code with) for internal behavior too. In this case, and for
empty returns, they're raising exceptions, catching them and then doing
what they want to. I suppose, if you don't want the method returning
None, you could catch that exception and return something else. Or
return nothing at all, which is what I usually want to do when those
pesky Nones crop up.  But I'm not entirely sure how you would make it
return nothing at all.



From cr2001 at hotmail.co.nz  Tue Jan  3 21:47:43 2017
From: cr2001 at hotmail.co.nz (Callum Robinson)
Date: Tue, 3 Jan 2017 18:47:43 -0800 (PST)
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <mailman.203.1483497338.2395.python-list@python.org>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <26855fa4-dc40-43ae-9eaa-15dc1de97842@googlegroups.com>
 <07f87e48-6bb3-ad25-6f4f-7d350c5b794a@mrabarnett.plus.com>
 <mailman.199.1483495538.2395.python-list@python.org>
 <9a5a2843-4d4b-43de-b580-85889447e284@googlegroups.com>
 <c6a382bd-8401-5814-c1ed-42b3d1cc8043@lucidity.plus.com>
 <mailman.203.1483497338.2395.python-list@python.org>
Message-ID: <f6201b85-9e10-48c3-8f53-cf591ec40be4@googlegroups.com>

On Wednesday, January 4, 2017 at 3:35:53 PM UTC+13, Erik wrote:
> On 04/01/17 02:24, Callum Robinson wrote:
> > On Wednesday, January 4, 2017 at 3:05:48 PM UTC+13, MRAB wrote:
> >> What values can 'is_same' return?
> >>
> >> Which of those values are you checking for in the loop?
> >
> > I'm sorry but i do not completely understand what you are stating
> 
> You need to think about the specific things (their type, their exact 
> values) that your functions might return. Printing some trace output is 
> a classic way of debugging your program. If, after this line:
> 
>  >>>> higher_or_lower = is_same(computer_number, guess)
> 
> ... you added:
> 
> print (higher_or_lower)
> 
> ... what values do you then see being output? How will those values be 
> processed by the conditions you see that work on the "higher_or_lower" 
> variable?
> 
> E.

I did it and this is what it states when i run it

hello. 
I have thought of a number between 1 and 100.
Can you guess it?
5
Low
Sorry , you are too high. Try again. 

Does this mean the number i entered is to low but the code is still stating it is to high?


From steve+comp.lang.python at pearwood.info  Tue Jan  3 21:50:34 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 04 Jan 2017 14:50:34 +1200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I do
References: <1881369740@f38.n261.z1.binkp.net>
Message-ID: <1246545673@f38.n261.z1.binkp.net>

On Wednesday 04 January 2017 12:10, Cameron Simpson wrote:

> On 03Jan2017 12:57, Steve D'Aprano <steve+python at pearwood.info> wrote:
>>I dislike the Unix-style Vim/Emacs text editors, I prefer a traditional
>>GUI-based editor. So my "IDE" is:
>>- Firefox, for doing searches and looking up documentation;
>>- an GUI programmer's editor, preferably one with a tab-based
>>  interface, such as geany or kate;
>>- a tab-based terminal.
>
> "traditional GUI-based editor"
>
> For those of us who spent a lot of our earlier time on terminals (actual
> physical terminals) we consider GUIs "new fangled".
>
> Just narking,
> Cameron Simpson <cs at zip.com.au>


Heh, GUI editors have been around since at least 1984, if not older, which 
makes them older than half the programmers in the world.

I'm not sure what an *un*traditional GUI-based editor would look like. Maybe 
one that used a ribbon-based interface, like MS Office? Or perhaps Leo?

http://leoeditor.com/

[My resolution for 2017: stop talking about Leo and actually download the damn 
thing and try it out.]



--
Steven
"Ever since I learned about confirmation bias, I've been seeing it everywhere." 
- Jon Ronson



From steve+comp.lang.python at pearwood.info  Tue Jan  3 21:50:34 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 04 Jan 2017 14:50:34 +1200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I do
Message-ID: <2012295452@f38.n261.z1.binkp.net>

On Wednesday 04 January 2017 12:10, Cameron Simpson wrote:

> On 03Jan2017 12:57, Steve D'Aprano <steve+python at pearwood.info> wrote:
>>I dislike the Unix-style Vim/Emacs text editors, I prefer a traditional
>>GUI-based editor. So my "IDE" is:
>>- Firefox, for doing searches and looking up documentation;
>>- an GUI programmer's editor, preferably one with a tab-based
>>  interface, such as geany or kate;
>>- a tab-based terminal.
>
> "traditional GUI-based editor"
>
> For those of us who spent a lot of our earlier time on terminals (actual
> physical terminals) we consider GUIs "new fangled".
>
> Just narking,
> Cameron Simpson <cs at zip.com.au>


Heh, GUI editors have been around since at least 1984, if not older, which 
makes them older than half the programmers in the world.

I'm not sure what an *un*traditional GUI-based editor would look like. Maybe 
one that used a ribbon-based interface, like MS Office? Or perhaps Leo?

http://leoeditor.com/

[My resolution for 2017: stop talking about Leo and actually download the damn 
thing and try it out.]



--
Steven
"Ever since I learned about confirmation bias, I've been seeing it everywhere."
- Jon Ronson



From python at deborahswanson.net  Tue Jan  3 21:58:42 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 04 Jan 2017 14:58:42 +1200
Subject: Clickable hyperlinks
Message-ID: <786148622@f38.n261.z1.binkp.net>

Chris Angelico wrote, on January 04, 2017 4:16 AM
>
> On Wed, Jan 4, 2017 at 10:43 PM, Deborah Swanson
> <python at deborahswanson.net> wrote:
> > I'm quite well aware by now that there is no one-sentence
> answer to my
> > original question, if there's any coherent answer at all.
> Them's the
> > breaks. Live with it or live without it, it doesn't care.
>
> Yeah, there's no simple answer; however, you'll find that
> Python on many platforms is entirely capable of popping a URL
> up in the user's default browser. Check this out:
>
> >>> import antigravity
>
> This uses the 'webbrowser' module, which knows about a number
> of different ways to open a browser, and will attempt them
> all. So if you can figure out the UI part of things, actually
> making the link pop up in a browser isn't too hard; for
> instance, if you're doing OAuth at the command line and need
> the user to go and authenticate, you can simply
> webbrowser.open("http://......./") and it'll DTRT.
>

Thank you, thank you! Finally, at least one person on this list knows about 
something (anything) in the python world that is internet aware. It's also 
occurred to me that Beautifulsoup downloads data from a url, so that code must 
have access to some kind of an internet engine too.

I googled antigravity and found a number of interesting links.

The History of Python: import antigravity 
http://python-history.blogspot.com/2010/06/import-antigravity.html

Among other things, it was added to Python 3 in 2010, so it's been around a 
little while. And a comment mentions that "The antigravity module is also 
included in Python 2.7."

And a reddit poster tells us that "if you type 'import antigravity' into a 
Python command line your default browser opens the XKCD comic 'Python' in a 
tab."
https://www.reddit.com/r/ProgrammerHumor/comments/1hvb5n/til_if_you_type
_import_antigravity_into_a_python/

An "import antigravity" video at
https://www.youtube.com/watch?v=_V0V6Rk6Fp4

And its page in the Package Index:
https://pypi.python.org/pypi/antigravity/0.1, with a Page Not Found Error for 
the Home Page. So it doesn't look like there's any alternative but to download 
it and look at the code.

Yes, I'd gotten as far as figuring out that you don't need a clickable link. 
Code that opens a url in a browse would do the job just fine. Or the 
webbrowser.open("http://......./") in a Linux terminal you suggest. (I just 
have to get my Linux machine up and running again to try it.)

All in all, given that clickable urls in a console is a non-starter, this hits 
the nail on the head. Many thanks again!

Deborah



From steve+comp.lang.python at pearwood.info  Tue Jan  3 22:04:02 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 04 Jan 2017 15:04:02 +1200
Subject: Clickable hyperlinks
References: <1619621956@f38.n261.z1.binkp.net>
Message-ID: <3040162315@f38.n261.z1.binkp.net>

On Wednesday 04 January 2017 14:04, Deborah Swanson wrote:

> Steve D'Aprano wrote, on January 03, 2017 4:56 PM
[...]
>> Python can't force the console to treat something as a
>> clickable link, if the console has no capacity for clickable
>> links. Nor can Python predict what format the console uses to
>> recognise a link.
>>
>> The best you can do is to experiment with a couple of simple
>> formats and see which, if any, your console understands:
>>
>> # HTML
>> <a href="http://www.example.com">Example.</a>
>>
>> # URL in angle brackets
>> Example <http://www.example.com>
>>
>> # URL alone
>> http://www.example.com
>>
>> # I can't remember what these are called
>> <url:http://www.example.com>
>>
>> # Markup
>> [Example](http://www.example.com)
>>
>> # Rest
>> `Example <http://www.example.com>`_
[...]

> I tried all of your examples in IDLE, and they all get syntax errors.
> I'd expect the same from PyCharm, though I didn't try it.

Syntax errors? How can you get syntax errors from *output* text?

The above are just text, no different from:

    Hello World!


Of course you have to put quotes around them to enter them in your source code. 
We don't expect this to work:

    print(Hello World!)


you have to use a string literal with quotes:

    print('Hello World!')


Same for all of the above.

py> print('<a href="http://www.example.com">Example.</a>')
<a href="http://www.example.com">Example.</a>


That's the Python interactive interpreter (with a custom prompt, I prefer "py>" 
rather than the default ">>>"). Or I can do this from the operating system's 
shell prompt:

steve at runes:~$ python -c "print 'http://www.example.com'" 
http://www.example.com


If I do this in GNOME Terminal 2.30.2, the URL http... is a clickable link. But 
that's specific to the terminal. Other terminals may or may not recognise it.




--
Steven
"Ever since I learned about confirmation bias, I've been seeing it everywhere." 
- Jon Ronson



From python at deborahswanson.net  Tue Jan  3 22:04:36 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 19:04:36 -0800
Subject: Clickable hyperlinks
In-Reply-To: <586c4834$0$1591$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <00a501d26637$485f8660$27b23dae@sambora>

Steve D'Aprano wrote, on January 03, 2017 4:56 PM

> On Wed, 4 Jan 2017 10:32 am, Deborah Swanson wrote:
> 
> 
> > The GUI consoles I have are in Pycharm, the IDLE that comes with 
> > Anaconda, and Spyder. PyCharm and IDLE both ask for internet access 
> > when I open them, so they're capable of opening links, but whether 
> > that means their output space is capable of handling 
> clickable links I 
> > don't know.
> > 
> > I do know printing a full url with the %s specifier or 
> entering a url 
> > and clicking enter just gives you the plain text url. 
> Obviously, not 
> > all GUI consoles are enabled recognize and make clickable 
> links from 
> > correctly formatted urls.
> > 
> > I was hoping there was some functionality in python to make 
> clickable 
> > links. Could be a package, if the core language doesn't have it.
> 
> Unfortunately there is no such thing as an application- 
> independent "clickable link".

I'm getting that.
 
> Excel can make clickable links, because it only has to deal 
> with a single suite of related applications: Excel, Word, and 
> the rest of Microsoft Office. Likewise LibreOffice.
> 
> But Python has to deal with an infinite number of potential 
> or hypothetical consoles, and there is no standard for 
> "clickable links" that all, or even most, consoles understand.
> 
> Python can't force the console to treat something as a 
> clickable link, if the console has no capacity for clickable 
> links. Nor can Python predict what format the console uses to 
> recognise a link.
> 
> The best you can do is to experiment with a couple of simple 
> formats and see which, if any, your console understands:
> 
> # HTML
> <a href="http://www.example.com">Example.</a>
> 
> # URL in angle brackets
> Example <http://www.example.com>
> 
> # URL alone
> http://www.example.com
> 
> # I can't remember what these are called <url:http://www.example.com>
> 
> # Markup
> [Example](http://www.example.com)
> 
> # Rest
> `Example <http://www.example.com>`_
> 
> 
> 
> 
> 
> -- 
> Steve
> "Cheer up," they said, "things could be worse." So I cheered 
> up, and sure enough, things got worse.

I tried all of your examples in IDLE, and they all get syntax errors.
I'd expect the same from PyCharm, though I didn't try it.

I think I need to write a class to do it in a particular application,
preferably in PyCharm, though I'd need some kind of internet access
engine to do it anywhere. I can look up how Firefox does it, pretty sure
I have that somewhere. Maybe there's a way...

Maybe it's a stupid idea, but originally I wanted to output links and
click on them while I was still debugging in PyCharm, without having to
save the csv and reopen it in Excel, to see what was in a listing* while
I was still debugging. PyCharm does have links in its console output
that take you to positions in the code when you click on them, so it
seems like all the basic infrastructure is there. I just have to figure
out how to do it for internet urls that I output.

* listing is a real estate listing with a url, part of a project I'm
working on, in case you haven't read the "Cleaning up conditionals"
thread.



From python at lucidity.plus.com  Tue Jan  3 22:11:26 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 4 Jan 2017 03:11:26 +0000
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <f6201b85-9e10-48c3-8f53-cf591ec40be4@googlegroups.com>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <26855fa4-dc40-43ae-9eaa-15dc1de97842@googlegroups.com>
 <07f87e48-6bb3-ad25-6f4f-7d350c5b794a@mrabarnett.plus.com>
 <mailman.199.1483495538.2395.python-list@python.org>
 <9a5a2843-4d4b-43de-b580-85889447e284@googlegroups.com>
 <c6a382bd-8401-5814-c1ed-42b3d1cc8043@lucidity.plus.com>
 <mailman.203.1483497338.2395.python-list@python.org>
 <f6201b85-9e10-48c3-8f53-cf591ec40be4@googlegroups.com>
Message-ID: <38efa069-5beb-bbc9-72d6-09280cd4f79e@lucidity.plus.com>

On 04/01/17 02:47, Callum Robinson wrote:
> On Wednesday, January 4, 2017 at 3:35:53 PM UTC+13, Erik wrote:
> I did it and this is what it states when i run it
>
> hello.
> I have thought of a number between 1 and 100.
> Can you guess it?
> 5
> Low
> Sorry , you are too high. Try again.
>
> Does this mean the number i entered is to low but the code is still stating it is to high?

The last code you posted will return "low", "high" or "win" from the 
"is_same()" function. How does that relate to the "Low" that you are now 
printing?

You must have changed something. If you are testing strings as return 
values then they must be _exactly_ the same - including case and spaces etc.

Always remember that your computer is an idiot. It's the fastest idiot 
that you'll ever know, and it could become your best friend. But it IS 
an idiot ;)

E.


From steve+comp.lang.python at pearwood.info  Tue Jan  3 22:16:58 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 04 Jan 2017 14:16:58 +1100
Subject: Hey, I'm new to python so don't judge.
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <26855fa4-dc40-43ae-9eaa-15dc1de97842@googlegroups.com>
 <07f87e48-6bb3-ad25-6f4f-7d350c5b794a@mrabarnett.plus.com>
 <mailman.199.1483495538.2395.python-list@python.org>
 <9a5a2843-4d4b-43de-b580-85889447e284@googlegroups.com>
Message-ID: <586c692c$0$2860$c3e8da3$76491128@news.astraweb.com>

On Wednesday 04 January 2017 13:24, Callum Robinson wrote:

> On Wednesday, January 4, 2017 at 3:05:48 PM UTC+13, MRAB wrote:
>> On 2017-01-04 01:37, Callum Robinson wrote:
>> > On Wednesday, January 4, 2017 at 12:49:28 PM UTC+13, Callum Robinson
>> > wrote:
>> >> Im doing a new task from my teacher but i can't seem to find what is
>> >> wrong with this code. Can anyone help?
>> >>
>> >> #mynumber.py
>> >> # this game uses a home made function
>> >> import random
>> >>
>> >> #think of a number
>> >> computer_number = number.randint(1,100)
>> >>
>> >> #create the function is_same()
>> >> def is_same(target, number:
>> >>         if target == number:
>> >>             result="win"
>> >>         elif target > number:
>> >>             result="low"
>> >>         else:
>> >>             result="high"
>> >>         return result
>> >>
>> >> # start the game
>> >> print("hello. \nI have thought of a number between 1 and 100.")
>> >>
>> >> #collect the user's guess as an interger
>> >> guess = int(input("Can you guess it? "))
>> >> #Use our function
>> >> higher_or_lower = is_same(computer_number, guess)
>> >> #run the game untill the user is correct
>> >> while higher_or_lower != "win"
>> >>     if higher_or_lower == "to low"
>> >>          guess = int(input("Sorry, you are too low. Try again."))
>> >>     else:
>> >>         guess = int(input("Sorry your are too high. Try again."))
>> >>
>> >>     higher_or_lower = is_same(computer_number, guess)
>> >>
>> >> #end of game
>> >> input("Correct!\nWell Done\n\n\nPress RETURN to exit.")
>> >
>> > Hey again, i'm sorry for bothering you with so many questions i just did
>> > not want to keep asking my teacher who is on holiday these.
>> >
>> > I have another issue where the code runs but i can guess every number from
>> > 1-100 but it always says Sorry your are too high. Try again. I don't
>> > understand what i have done to cause this.
>> >
>> What values can 'is_same' return?
>> 
>> Which of those values are you checking for in the loop?
> 
> I'm sorry but i do not completely understand what you are stating

That's okay, you're still learning :-)

We've all been where you are, even if some of us have forgotten what its like.


Look at your is_same() function. It can return three different things, which 
gets stored in the higher_or_lower variable:

- "win"
- "low"
- "high"


But now look at how you check the result:

while higher_or_lower != "win"
    if higher_or_lower == "to low"
        guess = int(input("Sorry, you are too low. Try again."))
    else:
        guess = int(input("Sorry your are too high. Try again."))


I see a typo that will prevent your code from running: you are missing a colon 
after the first line, it should say:

while higher_or_lower != "win":

Likewise for the "if ..." line, it also needs to end with a colon.

So the first thing is that when asking for help, be *extra careful* that the 
code you show us is the same as the code you are actually running. (Otherwise 
we waste our time trying to debug code that you aren't even using!) You should 
always COPY AND PASTE your code, not retype it.

But let's assume that your actual code does include the needed colons, so it 
will run. What values do you check for?

- "to low"

and that's it. Look again at the values that higher_or_lower can actually be. 
Is there any way that higher_or_lower gets the value "to low"?

No. Remember that Python can't read your mind and realise that when you check 
for "to low", you actually mean just "low". So there is no way that the first 
if... clause will be triggered, so it always falls through to the else clause 
and prints "Sorry your are too high. Try again."

(P.S. you mean "Sorry you are too high", not "your are".)



-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From steve+comp.lang.python at pearwood.info  Tue Jan  3 22:25:35 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 04 Jan 2017 14:25:35 +1100
Subject: Hey, I'm new to python so don't judge.
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <de17ea17-a783-4b03-bdd6-7ac5afa63c51@googlegroups.com>
 <aaaddf7e-8835-4860-7338-69fc55376fbe@lucidity.plus.com>
 <mailman.186.1483489577.2395.python-list@python.org>
 <5e69d496-f5d3-4aab-ae78-3d1d57d3aee4@googlegroups.com>
 <71b9f7e5-c255-435f-e7d6-3cc7abce35b4@lucidity.plus.com>
 <mailman.187.1483490711.2395.python-list@python.org>
 <3021b6e8-d843-413f-a62b-f51461ed1b49@googlegroups.com>
 <586c4ccf$0$1602$c3e8da3$5496439d@news.astraweb.com>
 <b87802f8-116c-4e8e-b7b4-61cfb1c3af60@googlegroups.com>
Message-ID: <586c6b31$0$11110$c3e8da3@news.astraweb.com>

On Wednesday 04 January 2017 12:25, Callum Robinson wrote:

> Hey man thanks, the sad thing is i have no idea why i put that in. I must be
> having a terrible day.

Don't worry about it. The difference between a beginner and an expert is *not* 
that experts make fewer mistakes, but that experts know how to fix those 
mistakes so quickly that they don't even notice them.

I know people who are seemingly incapable of typing more than three words in 
the row without two typos, but they manage to be excellent programmers. They'll 
typo some code:

    comptuer_number = number.radnint(1, 100)

try to run it, realise their mistake and fix it:

    comptuer_number = random.radnint(1, 100)


then run it again and realise there is at least one more mistake, and fix it:

    comptuer_number = random.randint(1, 100)


and then a third time:

    computer_number = random.randint(1, 100)


while a beginner is still puzzling over their first mistake. Don't stress about 
it, it is all just part of the learning process. All code starts off full of 
bugs.




-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From grant.b.edwards at gmail.com  Tue Jan  3 22:35:16 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Wed, 04 Jan 2017 15:35:16 +1200
Subject: Clickable hyperlinks
Message-ID: <4013467634@f38.n261.z1.binkp.net>

On 2017-01-03, Deborah Swanson <python at deborahswanson.net> wrote:
> Grant Edwards wrote, on January 03, 2017 3:13 PM
>>
>> On 2017-01-03, Deborah Swanson <python at deborahswanson.net> wrote:
>>
>> > I'm sorry, I should have said a GUI console because I
>> wouldn't expect
>> > a text-based console to produce clickable links.
>>
>> What's a "GUI console"?

> The GUI consoles I have are in Pycharm, the IDLE that comes with
> Anaconda, and Spyder. PyCharm and IDLE both ask for internet access when
> I open them, so they're capable of opening links, but whether that means
> their output space is capable of handling clickable links I don't know.

Thanks, that's a bit clearer.  For those of us from the Unix world "console" 
means something else.

> I do know printing a full url with the %s specifier or entering a url
> and clicking enter just gives you the plain text url. Obviously, not all
> GUI consoles are enabled recognize and make clickable links from
> correctly formatted urls.
>
> I was hoping there was some functionality in python to make clickable
> links. Could be a package, if the core language doesn't have it.

There is no definition for what a "clickable link" is unless you're sending 
HTML to a web browser.  That means there's no way to create funcationality to 
make one.

--
Grant Edwards               grant.b.edwards        Yow! I'm not an Iranian!!
                                  at               I voted for Dianne
                              gmail.com            Feinstein!!



From grant.b.edwards at gmail.com  Tue Jan  3 22:42:28 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Wed, 04 Jan 2017 15:42:28 +1200
Subject: Clickable hyperlinks
Message-ID: <4217700806@f38.n261.z1.binkp.net>

On 2017-01-04, Michael Torrie <torriem at gmail.com> wrote:

> On my Linux machine, the terminal emulators I've used all make a regular
> url printed out into a clickable link (or at least a right-clickable
> link).  This is just something they try to do with all things that look
> like urls.  Sometimes it's helpful, often it's annoying.

What I have done is defined a window manager root menu entry that opens a web 
browser on the current text selection.  That lets me "click" on a link in any 
application that suport the standard X11 text-selection mechanism (which is 
almost all of them).

>> I was hoping there was some functionality in python to make clickable
>> links. Could be a package, if the core language doesn't have it.
>
> No, there is not.  If you made a full GUI app using a toolkit like
> GTK or Qt, you can indeed place hyperlinks on your forms and the
> operating system will automatically connect them to the web browser.
> But not in text-mode terminal apps.

For me it's double-click to select the url in the terminal window or PDF viewer 
or whaterver, then right-click on the root window and pick
the menu entry that says 'Firefox [sel]' or 'Chrome [sel]'.  It's a few extra 
steps, but it works for almostly any application that displays text.

--
Grant Edwards               grant.b.edwards        Yow! Where do your SOCKS
                                  at               go when you lose them in
                              gmail.com            th' WASHER?



From python at deborahswanson.net  Tue Jan  3 22:46:45 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 19:46:45 -0800
Subject: Clickable hyperlinks
In-Reply-To: <CAMPXz=oMYFvasoOqAhFibnuy1sJGKfwRzcy7Uu3GzYofv5wtjA@mail.gmail.com>
Message-ID: <00ab01d2663d$2c556d80$27b23dae@sambora>

David wrote, on January 03, 2017 6:36 PM
> 
> On 4 January 2017 at 11:50, Deborah Swanson 
> <python at deborahswanson.net> wrote:
> > Erik wrote, on January 03, 2017 3:30 PM
> >>
> >> When you start a new topic on the list, could you please 
> write a new 
> >> message rather than replying to an existing message and 
> changing the 
> >> title/subject?
> >>
> > Certainly. I've been on many other lists before (but none 
> since about 
> > 2011), and no one complained of or even mentioned this 
> problem. But if 
> > it's a problem with some email readers now, I can easily 
> just start a 
> > new message.  Just being lazy and following old habits, I guess. ;)
> 
> To be clear, the problem is not "with some email readers".

Actually it is, or at least it doesn't happen in all email readers.
Mine, for instance, never breaks up threads.
 
> The problem is that it breaks the thread management features 
> that are built into every email message, making it impossible 
> to display threads correctly.

Again, I think this is in some modern email readers. Apparently older
ones were more robust.

> As can be seen here for example: 
> https://mail.python.org/pipermail/python->
list/2017-January/thread.html
> 
> Note how most threads start in the leftmost column and 
> replies are indented. But this does not occur where you began 
> the new subject: "Clickable hyperlinks".

Yes, pipermail does seem to have a few bugs, this is the second one I've
seen.
 
> Thanks.

I did say in the message you're replying to that I will try to remember
to start new threads with brand new messages. (Even though I think
pipermail's behavior is a bug, that's what many people read the list
from.)



From steve+comp.lang.python at pearwood.info  Tue Jan  3 22:50:35 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 04 Jan 2017 14:50:35 +1100
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
References: <586b0517$0$1584$c3e8da3$5496439d@news.astraweb.com>
 <20170104011030.GA46099@cskk.homeip.net>
 <mailman.197.1483494950.2395.python-list@python.org>
Message-ID: <586c710d$0$11099$c3e8da3@news.astraweb.com>

On Wednesday 04 January 2017 12:10, Cameron Simpson wrote:

> On 03Jan2017 12:57, Steve D'Aprano <steve+python at pearwood.info> wrote:
>>I dislike the Unix-style Vim/Emacs text editors, I prefer a traditional
>>GUI-based editor. So my "IDE" is:
>>- Firefox, for doing searches and looking up documentation;
>>- an GUI programmer's editor, preferably one with a tab-based
>>  interface, such as geany or kate;
>>- a tab-based terminal.
> 
> "traditional GUI-based editor"
> 
> For those of us who spent a lot of our earlier time on terminals (actual
> physical terminals) we consider GUIs "new fangled".
> 
> Just narking,
> Cameron Simpson <cs at zip.com.au>


Heh, GUI editors have been around since at least 1984, if not older, which 
makes them older than half the programmers in the world.

I'm not sure what an *un*traditional GUI-based editor would look like. Maybe 
one that used a ribbon-based interface, like MS Office? Or perhaps Leo?

http://leoeditor.com/

[My resolution for 2017: stop talking about Leo and actually download the damn 
thing and try it out.]



-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From torriem at gmail.com  Tue Jan  3 22:51:37 2017
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 3 Jan 2017 20:51:37 -0700
Subject: Clickable hyperlinks
In-Reply-To: <00a801d2663a$a76e0f70$27b23dae@sambora>
References: <00a801d2663a$a76e0f70$27b23dae@sambora>
Message-ID: <2c2aa0ca-ac6f-448c-95cc-0750f67cc041@gmail.com>

On 01/03/2017 08:28 PM, Deborah Swanson wrote:
> I think you're making this too complicated. I meant a console in a GUI
> application.

Ahh. Well, a "console in a GUI application" is whatever you make it[1].
There's no single "GUI console" hence my confusion and the confusion
expressed by the other poster.  I was under the impression you are
talking about printing something to standard out with, for example,
print().  Is this so, or are you using a GUI toolkit to construct your
application.  What GUI toolkit are you using?  As I said, in Qt or GTK
there are various ways to display hyperlinks.  For example, Qt lets you
place a hyperlink in a form, or inside of a text entry/display widget.

I still get the impression that you're working with standard out, using
print(). If so, then no, there's not going to be a way to force the OS
to make the output clickable, at least on Windows.

> Not true. Pycharm uses links in it's console output, they just aren't
> internet links. They link back to lines of code being referred to.

I think the problem here is the terminology with specific meaning in
Windows and Linux.  I'm referring to either the Win32 console window
(which is where cmd.exe runs), or a terminal emulator in Linux, which is
where you can interact with the bash shell and run command-line
programs.  When people normally run python apps that are not graphical,
they normally do it from the Windows console (via cmd.exe) or in Linux
from Bash running in a terminal emulator.  Graphical apps do their own
thing as far as displaying data and making windows with clickable links
in them.

[1] PyCharm and IDLE make "console" windows that are really normal GUI
windows and they direct the output from Python apps there. They may also
choose to display clickable links for things like errors. But once the
app is run outside of PyCharm, the output of the app would go to either
a Windows console window, or a terminal in Linux.  If you wanted your
app to make it's own window and display clickable links, you're back to
looking at a GUI toolkit (which is what PyCharm and IDLE are built with)
like Qt, GTK, Tk, wxWidgets, or something else.




From ceh329 at gmail.com  Tue Jan  3 23:02:52 2017
From: ceh329 at gmail.com (Charles Heizer)
Date: Wed, 04 Jan 2017 16:02:52 +1200
Subject: MySQL schema sync or diff
Message-ID: <520540773@f38.n261.z1.binkp.net>

Hello,
I have a MySQL database that is not managed (yet) and I would like to get an 
output or diff against my new model file. I'm using flask-sqlalchemy.

Are there any modules that would help me discover the differences so that I can 
script a migration to begin using flask-migrate?

Thanks!



From steve+comp.lang.python at pearwood.info  Tue Jan  3 23:04:02 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 04 Jan 2017 15:04:02 +1100
Subject: Clickable hyperlinks
References: <586c4834$0$1591$c3e8da3$5496439d@news.astraweb.com>
 <00a501d26637$485f8660$27b23dae@sambora>
 <mailman.206.1483499043.2395.python-list@python.org>
Message-ID: <586c7434$0$1617$c3e8da3$5496439d@news.astraweb.com>

On Wednesday 04 January 2017 14:04, Deborah Swanson wrote:

> Steve D'Aprano wrote, on January 03, 2017 4:56 PM
[...]
>> Python can't force the console to treat something as a
>> clickable link, if the console has no capacity for clickable
>> links. Nor can Python predict what format the console uses to
>> recognise a link.
>> 
>> The best you can do is to experiment with a couple of simple
>> formats and see which, if any, your console understands:
>> 
>> # HTML
>> <a href="http://www.example.com">Example.</a>
>> 
>> # URL in angle brackets
>> Example <http://www.example.com>
>> 
>> # URL alone
>> http://www.example.com
>> 
>> # I can't remember what these are called 
>> <url:http://www.example.com>
>> 
>> # Markup
>> [Example](http://www.example.com)
>> 
>> # Rest
>> `Example <http://www.example.com>`_
[...]

> I tried all of your examples in IDLE, and they all get syntax errors.
> I'd expect the same from PyCharm, though I didn't try it.

Syntax errors? How can you get syntax errors from *output* text?

The above are just text, no different from:

    Hello World!


Of course you have to put quotes around them to enter them in your source code. 
We don't expect this to work:

    print(Hello World!)


you have to use a string literal with quotes:

    print('Hello World!')


Same for all of the above.

py> print('<a href="http://www.example.com">Example.</a>')
<a href="http://www.example.com">Example.</a>


That's the Python interactive interpreter (with a custom prompt, I prefer "py>" 
rather than the default ">>>"). Or I can do this from the operating system's 
shell prompt:

steve at runes:~$ python -c "print 'http://www.example.com'"
http://www.example.com


If I do this in GNOME Terminal 2.30.2, the URL http... is a clickable link. But 
that's specific to the terminal. Other terminals may or may not recognise it.




-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From torriem at gmail.com  Tue Jan  3 23:05:18 2017
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 3 Jan 2017 21:05:18 -0700
Subject: Clickable hyperlinks
In-Reply-To: <00ab01d2663d$2c556d80$27b23dae@sambora>
References: <00ab01d2663d$2c556d80$27b23dae@sambora>
Message-ID: <03e6b340-fa99-cfe7-8c5d-ba2dcd0b7aa0@gmail.com>

On 01/03/2017 08:46 PM, Deborah Swanson wrote:
> Actually it is, or at least it doesn't happen in all email readers.
> Mine, for instance, never breaks up threads.

Mine doesn't either, which illustrates the issue. This  message, for
example appears under a long thread that started out life as "mentor
training python Romania with certification" and then changed to
"Cleaning up conditionals" and then changed to "Clickable hyperlinks."
All in one thread. My client doesn't break them up because they all tie
together via the message-id header.

And most of us would not like our client to break a thread just because
the subject changes. Often in long conversations there are twists and
turns in the discussion and sometimes side-paths are explored, and the
subject often is changed to reflect this.  With a truly threaded email
reader (one that shows a tree of messages, not just chronological
order), this works out very well.  So if a discussion has a natural
evolution into various other topics, it is often considered okay to just
change the subject but continue the thread. Other times, it's better to
start a new thread.  Where that line is is hard to say!

> I did say in the message you're replying to that I will try to remember
> to start new threads with brand new messages. (Even though I think
> pipermail's behavior is a bug, that's what many people read the list
> from.)

Sounds good.

I don't know of anyone that reads on the pipermail archive, except in
response to web searches.  Most people use clients of some kind, NNTP or
email.  And those that group messages according to message-id (most
clients except for ones that try to be smart like Gmail web or Outlook)
will show all the topics I mentioned before as one giant thread, which
is by design (that's what message-id headers are for).



From python at deborahswanson.net  Tue Jan  3 23:07:08 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 04 Jan 2017 16:07:08 +1200
Subject: Clickable hyperlinks
Message-ID: <2359161402@f38.n261.z1.binkp.net>

D'Arcy Cain wrote, on Wednesday, January 04, 2017 5:03 AM
>
> Deborah - please trim your quoted text.

Yes, I will. Some lists want to have it all to review in one message, some want 
it trimmed to just the lines you are responding to. I was just waiting to see 
what this list wants.

> On 2017-01-04 04:32 AM, Deborah Swanson wrote:
<snip>

> > But we aren't trying to print strings here, the point is to produce
> > clickable links. I didn't enclose them with quotes because I didn't
> > see any point in printing plain text when I wanted
> clickable links. I
>
> I'm not sure what your links are composed of but mine all look like
> sequences of characters or "strings."  It sounds like you are
> trying to
> make URL a first class type like strings. integers, floats, etc.  I
> can't think of any language that treats URLs as first class objects.
> Even HTML needs quotes:
>
>    <A HREF="http://...">Go here</A>

It seemed reasonable that you might be able to print urls, which is why I tried 
the experiment with all of Steven's suggested formats. But I was highly 
skeptical that any would work without some kind of modifiers to a bare print 
statement.

> > actually didn't understand why you thought I should print
> them, but it
>
> You want to output them to something.  That often involves
> printing them
> to a particular handler.

Yes, that's one of the things I would expect if we could print them.

> > never would have occurred to me that you wanted me to print out a
> > bunch of silly plain text strings, apparently just for the
> heck of it.
>
> Is that really what you got from his message?

Please forgive me, and I hope Steven forgives me too, but I was sick to death 
of all the beating on a dead horse (using Python to make clickable links in a 
console, any console). I'd taken heart when he first suggested his print 
experiment, because it was a plausible approach. But I lost my temper when he 
upbraided me in this message for failing to enclose my strings in quotes, in a 
most patronizing kind of way, when printing out plain text was absolutely 
nowhere on the progress toward a solution scale. I've been quite impressed with 
Steven's knowledge and talent, and after fending off the throng of unseeing 
naysayers all afternoon, it was just a little too much. I really should have 
closed my email reader hours before I read and replied to this message. 
Shoulda, coulda, woulda.

<snip>

> I can assure you that FF prints the string at some point.  It
> may wrap
> it in HTML tags first but printing is what it does.  Also,
> the URLs are
> stored as strings.  SQLite has no URL type.  If it did then it would
> still store it as a string somewhere.  PostGreSQL would let
> you create a
> URL type if you wanted but you would still need to wrap it in quotes
> (single in this case) when you created the entry.

I have no doubt that some variant of printing is involved. Transporting urls to 
the internet is an output process. FF's sqlite implementation does store urls 
as a text field in at least 2 tables. I would be interested in how FF takes 
those text urls and opens web pages with them, although I've learned and 
figured out just today some ways that Python can also do it. Turns out 
clickable links were a red herring.

If Steven's original suggestion included anything but a bare print statement, 
like the use of a special specifier or linking the print statement to some 
module, the use of quoted strings would have at least been worthy of 
consideration. But we all know what print("http://www.wherever.com") would 
print, and it would be utterly worthless for the purpose at hand. Trying the 
print statement without the quotes was a least a possibility, if there was any 
awareness in the print code of urls and what to do with them. That was the 
whole point of this fishing expedition, as I saw it. To see if there was any 
undocumented or narrowly known-of features in the print code.

<snip>
> In all the messages in this thread I still don't understand what this
> "teensy advantage" is supposed to be.  Do you want to be able
> to do this:
>
>    make_web_link(http://...)
>
> instead of:
>
>    make_web_link("http://...")
>
> --
> D'Arcy J.M. Cain
> System Administrator, Vex.Net
> http://www.Vex.Net/ IM:darcy at Vex.Net
> VoIP: sip:darcy at Vex.Net

You probably didn't see my oneliner on the "why do it" part in the swarm of 
messages on this thread yesterday. In it I mentioned that the use would be to 
open urls in the data I'm working with while I'm debugging the code that uses 
them. I want to see what pages they open, without having to leave my IDE. 
(Obviously I'd have to open another .py file, but that would be easier and 
quicker than the alternatives.) I never intended my original question to be any 
more than a frivolous toss out into the sea, to see if anyone knew an answer. I 
was flat out astonished when it blew up into the mini-monster that it did.

Is make_web_link("http://...") valid python code? That's exactly the kind of 
answer I was looking for, and I will try it (or look it up if it needs 
something imported) as soon as I send this off. Thank you.

It's possible you caught just the tail end of a hot mess without seeing all the 
irrational vitriol and nonsense that led up to this message. Lucky you.

Deborah



From python at lucidity.plus.com  Tue Jan  3 23:22:59 2017
From: python at lucidity.plus.com (Erik)
Date: Wed, 4 Jan 2017 04:22:59 +0000
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <586c6b31$0$11110$c3e8da3@news.astraweb.com>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <de17ea17-a783-4b03-bdd6-7ac5afa63c51@googlegroups.com>
 <aaaddf7e-8835-4860-7338-69fc55376fbe@lucidity.plus.com>
 <mailman.186.1483489577.2395.python-list@python.org>
 <5e69d496-f5d3-4aab-ae78-3d1d57d3aee4@googlegroups.com>
 <71b9f7e5-c255-435f-e7d6-3cc7abce35b4@lucidity.plus.com>
 <mailman.187.1483490711.2395.python-list@python.org>
 <3021b6e8-d843-413f-a62b-f51461ed1b49@googlegroups.com>
 <586c4ccf$0$1602$c3e8da3$5496439d@news.astraweb.com>
 <b87802f8-116c-4e8e-b7b4-61cfb1c3af60@googlegroups.com>
 <586c6b31$0$11110$c3e8da3@news.astraweb.com>
Message-ID: <d2f60554-f46d-23d3-8a11-9bcc3b229716@lucidity.plus.com>

On 04/01/17 03:25, Steven D'Aprano wrote:
> On Wednesday 04 January 2017 12:25, Callum Robinson wrote:
>
>> Hey man thanks, the sad thing is i have no idea why i put that in. I must be
>> having a terrible day.
>
> Don't worry about it. The difference between a beginner and an expert is *not*
> that experts make fewer mistakes, but that experts know how to fix those
> mistakes so quickly that they don't even notice them.

Hmm. An expert at what? Telling a beginner how to spell something is not 
the same as coaxing that same beginner to think about something or 
approach a problem from a particular angle and come to their own 
solution. We all could have told him the answer up-front. What has that 
achieved?

E.


From python at deborahswanson.net  Tue Jan  3 23:46:31 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Tue, 3 Jan 2017 20:46:31 -0800
Subject: Clickable hyperlinks
In-Reply-To: <586c7434$0$1617$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <00b301d26645$8553e490$27b23dae@sambora>

Steven D'Aprano wrote, on January 03, 2017 8:04 PM
> 
> On Wednesday 04 January 2017 14:04, Deborah Swanson wrote:
> 
> > Steve D'Aprano wrote, on January 03, 2017 4:56 PM
> [...]
> >> Python can't force the console to treat something as a clickable 
> >> link, if the console has no capacity for clickable links. Nor can 
> >> Python predict what format the console uses to recognise a link.
> >> 
> >> The best you can do is to experiment with a couple of 
> simple formats 
> >> and see which, if any, your console understands:
> >> 
> >> # HTML
> >> <a href="http://www.example.com">Example.</a>
> >> 
> >> # URL in angle brackets
> >> Example <http://www.example.com>
> >> 
> >> # URL alone
> >> http://www.example.com
> >> 
> >> # I can't remember what these are called
> >> <url:http://www.example.com>
> >> 
> >> # Markup
> >> [Example](http://www.example.com)
> >> 
> >> # Rest
> >> `Example <http://www.example.com>`_
> [...]
> 
> > I tried all of your examples in IDLE, and they all get 
> syntax errors. 
> > I'd expect the same from PyCharm, though I didn't try it.
> 
> Syntax errors? How can you get syntax errors from *output* text?
>
> The above are just text, no different from:
> 
>     Hello World!
 
I closed the IDLE window these were on, but the error arrow was pointing
to punctuation in each case, a colon in one case, angle bracket in
another. Sorta seems like IDLE is trying to do something with them and
not taking them as simple plain text. But it's not making hyperlinks, so
I'm not sure how much I care exactly what it's doing.
 
> Of course you have to put quotes around them to enter them in 
> your source code. 
> We don't expect this to work:
> 
>     print(Hello World!)
> 
> 
> you have to use a string literal with quotes:
> 
>     print('Hello World!')
> 
> 
> Same for all of the above.

I didn't try printing them before, but I just did. Got:

>>> print([Example](http://www.example.com)
      
SyntaxError: invalid syntax  (arrow pointing at the colon)
 
> py> print('<a href="http://www.example.com">Example.</a>')
> <a href="http://www.example.com">Example.</a>
> 
> 
> That's the Python interactive interpreter (with a custom 
> prompt, I prefer "py>" 
> rather than the default ">>>"). Or I can do this from the 
> operating system's 
> shell prompt:
> 
> steve at runes:~$ python -c "print 'http://www.example.com'" 
http://www.example.com


If I do this in GNOME Terminal 2.30.2, the URL http... is a clickable
link. But 
that's specific to the terminal. Other terminals may or may not
recognise it.




-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson

I need to get a new power supply in my Linux-capable machine, but for
now I'm stuck with Winblows on a very old PC.

As I've mentioned in other posts on this thread, I'm now thinking that I
need to write a class to do this, and find out how Firefox and url aware
terminals in Linux do it. There must be a way.



From wrw at mac.com  Wed Jan  4 00:01:30 2017
From: wrw at mac.com (William Ray Wing)
Date: Wed, 04 Jan 2017 17:01:30 +1200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I do
Message-ID: <4292265760@f38.n261.z1.binkp.net>


> On Jan 4, 2017, at 3:44 PM, Dietmar Schwertberger <maillist at schwertberger.de>
wrote:
>
> On 04.01.2017 15:41, William Ray Wing wrote:
>> I use Wing, and I think you will like it.  It *is* pythonic, and for what it
is worth, offers remote debugging as one of its more recently added features.
> Obviously, you had no other choice than using Wing ;-)

I should have said something.  First, and to the best of my knowledge, I have 
no relationship with the Wing developers other than being a satisfied customer. 
Second, seven years ago, when I was reading IDE reviews and testing the more 
highly rated products, Wing just bubbled up to the top of the sieve I was using 
(features, ease of use, and the way it fit my idea of ? ?natural? ?, pretty 
much everyone's standard list).

>
> The remote debugging has been around for some years. I have been using it
quite often to debug on my Raspberry Pi, Nokia N900 and Jolla Phone, all 
running some Linux system. It works well. It is or was a bit complicated to set 
up. I think this has been improved with Wing 6, but I did not need it in the 
last weeks, so I don't know.

They claim it has been, but like you, I haven? ?t had need to test it on the 
new release.

Thanks,
Bill

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



From robertvstepp at gmail.com  Wed Jan  4 00:18:16 2017
From: robertvstepp at gmail.com (boB Stepp)
Date: Tue, 3 Jan 2017 23:18:16 -0600
Subject: Clickable hyperlinks
In-Reply-To: <00b301d26645$8553e490$27b23dae@sambora>
References: <586c7434$0$1617$c3e8da3$5496439d@news.astraweb.com>
 <00b301d26645$8553e490$27b23dae@sambora>
Message-ID: <CANDiX9L0dBWVp1BZBDi96eqXWF-N_N4YjguTXHR2gmrxm6tWyw@mail.gmail.com>

On Tue, Jan 3, 2017 at 10:46 PM, Deborah Swanson
<python at deborahswanson.net> wrote:
>

>
> I didn't try printing them before, but I just did. Got:
>
> >>> print([Example](http://www.example.com)
>
> SyntaxError: invalid syntax  (arrow pointing at the colon)

As Steve had said, you need to put everything inside quotes.  Also,
you are missing a matching paren.  Thus:

py3: print("[Example](http://www.example.com)")
[Example](http://www.example.com)

As to whether anything will be "clickable" or not, what has already
been said about different types of terminals applies.

-- 
boB


From steve+comp.lang.python at pearwood.info  Wed Jan  4 00:40:00 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 04 Jan 2017 16:40 +1100
Subject: Clickable hyperlinks
References: <586c7434$0$1617$c3e8da3$5496439d@news.astraweb.com>
 <00b301d26645$8553e490$27b23dae@sambora>
 <mailman.214.1483505156.2395.python-list@python.org>
Message-ID: <586c8ab3$0$1506$c3e8da3$5496439d@news.astraweb.com>

On Wednesday 04 January 2017 15:46, Deborah Swanson wrote:

> Steven D'Aprano wrote, on January 03, 2017 8:04 PM
[...]
>> Of course you have to put quotes around them to enter them in
>> your source code.
>> We don't expect this to work:
>> 
>>     print(Hello World!)
>> 
>> 
>> you have to use a string literal with quotes:
>> 
>>     print('Hello World!')
>> 
>> 
>> Same for all of the above.

> I didn't try printing them before, but I just did. Got:
> 
>>>> print([Example](http://www.example.com)
>       
> SyntaxError: invalid syntax  (arrow pointing at the colon)

You missed the part where I said you have to put them in quotes.

Like any other string in Python, you have to use quotation marks around it for 
Python to understand it as a string. None of these things will work:

print( Hello World! )

print( What do you want to do today? )

print( 3 2 1 blast off )

print( http://www.example.com )


This isn't specific to print. This won't work either:

message = Hello World!

In *all* of these cases, you have to tell Python you're dealing with a string, 
and you do that with quotation marks:

message = "Hello World!"
print( 'What do you want to do today?' )
count_down = '3 2 1 blast off'
url = 'http://www.example.com'




-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From torriem at gmail.com  Wed Jan  4 00:47:38 2017
From: torriem at gmail.com (Michael Torrie)
Date: Wed, 04 Jan 2017 17:47:38 +1200
Subject: Clickable hyperlinks
Message-ID: <2867895765@f38.n261.z1.binkp.net>

On 01/04/2017 03:58 PM, Deborah Swanson wrote:
> Thank you, thank you! Finally, at least one person on this list knows
> about something (anything) in the python world that is internet aware.
> It's also occurred to me that Beautifulsoup downloads data from a url,
> so that code must have access to some kind of an internet engine too.

Except that you never mentioned anything about this in your posts before. It 
seemed to me you were asking about printing out clickable hyperlinks with 
python.  Calling the OS to launch a browser to view a url is a different beast 
which is why no one mentioned it before.

If you don't tell us what you're actually trying to do (your end goal), things 
are more frustrating for everyone.  If you had said early on you just want to 
be able to send the user to a particular url in a web browser, what Chris 
suggested would have been said a long time ago, rather than focusing on console 
output which is what you were asking about and focusing attention on.

Just so you know, BeautifulSoup does not do any internet access itself; it's 
only an HTML parser. You have to fetch web pages using something like python's 
urllib and then feed the data to BeautifulSoup.  urllib is not a web browser 
though.  It can pretend to be a browser as far as the server is concerned but 
it knows nothing about javascript or rendering. It just retrieves bytes which 
you can then feed to BeautifulSoup or some other parser.

> Yes, I'd gotten as far as figuring out that you don't need a clickable
> link. Code that opens a url in a browse would do the job just fine.

Good! I just wish you would have mentioned this much earlier as your end goal.

> Or the webbrowser.open("http://......./") in a Linux terminal you suggest.
> (I just have to get my Linux machine up and running again to try it.)

The webbrowser module does not require console or terminal output. It will work 
on Windows or Linux if I'm not mistaken.  It asks the OS to launch the default 
browser and load the indicated url.

> All in all, given that clickable urls in a console is a non-starter,
> this hits the nail on the head. Many thanks again!



From rustompmody at gmail.com  Wed Jan  4 00:57:08 2017
From: rustompmody at gmail.com (Rustom Mody)
Date: Tue, 3 Jan 2017 21:57:08 -0800 (PST)
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <mailman.183.1483488743.2395.python-list@python.org>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
 <64837604-9f3a-806c-d631-fcc352738952@schwertberger.de>
 <mailman.183.1483488743.2395.python-list@python.org>
Message-ID: <0cb04e45-c91b-46ea-8f42-eec26fab7ca3@googlegroups.com>

On Wednesday, January 4, 2017 at 5:42:34 AM UTC+5:30, Dietmar Schwertberger wrote:
> On 02.01.2017 12:38, Antonio Caminero Garcia wrote:
> > The thing with the from-the-scratch full featured IDEs (Eclipse, IntelliJ, Pycharm) is that they look like a space craft dashboard and that unwarranted resources consumption and the unnecessary icons.
> You did not try Wing IDE? It looks less like a spacecraft. Maybe you 
> like it.
> Maybe the difference is that Wing is from Python people while the ones 
> you listed are from Java people.
> For something completely different (microcontroller programming in C) I 
> just switched to a Eclipse derived IDE and I don't like it too much as 
> the tool does not focus on the problem scope.
> 
>  From your posts I'm not sure whether you want an editor or an IDE, 
> where for me the main difference is the debugger and code completion.
> I would not want to miss the IDE features any more, even though in my 
> first 15 years of Python I thought that a debugger is optional with 
> Python ...
> 
> Regards,
> 
> Dietmar

Im surprised no one's talked of idle (or Ive missed it?)


From greg.ewing at canterbury.ac.nz  Wed Jan  4 01:00:10 2017
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Wed, 04 Jan 2017 19:00:10 +1300
Subject: Simulating int arithmetic with wrap-around
In-Reply-To: <8737gz4tlp.fsf@nightsong.com>
References: <58667385$0$1609$c3e8da3$5496439d@news.astraweb.com>
 <8737gz4tlp.fsf@nightsong.com>
Message-ID: <ed3hbbFi2mdU1@mid.individual.net>

Paul Rubin wrote:
> My first thought is towards the struct module, especially if you want to
> handle a bunch of such integers at the same time.  Or maybe the array
> module or some combination.

Or possibly numpy.

-- 
Greg


From dan at tombstonezero.net  Wed Jan  4 01:07:05 2017
From: dan at tombstonezero.net (Dan Sommers)
Date: Wed, 4 Jan 2017 06:07:05 -0000 (UTC)
Subject: Clickable hyperlinks
References: <586c7434$0$1617$c3e8da3$5496439d@news.astraweb.com>
 <00b301d26645$8553e490$27b23dae@sambora>
 <mailman.214.1483505156.2395.python-list@python.org>
 <586c8ab3$0$1506$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <o4i3e8$63u$1@dont-email.me>

On Wed, 04 Jan 2017 16:40:00 +1100, Steven D'Aprano wrote:

> On Wednesday 04 January 2017 15:46, Deborah Swanson wrote:
> 
>> Steven D'Aprano wrote, on January 03, 2017 8:04 PM
> [...]
>>> Of course you have to put quotes around them to enter them in
>>> your source code.
>>> We don't expect this to work:
>>> 
>>>     print(Hello World!)
>>> 
>>> you have to use a string literal with quotes:
>>> 
>>>     print('Hello World!')
>>> 
>>> Same for all of the above.
> 
>> I didn't try printing them before, but I just did. Got:
>> 
>>>>> print([Example](http://www.example.com)
>>       
>> SyntaxError: invalid syntax  (arrow pointing at the colon)
> 
> You missed the part where I said you have to put them in quotes.

ObPython:  "When I've got these antlers on I am dictating and when I
take them off I am not dictating."  :-)


From tjreedy at udel.edu  Wed Jan  4 01:21:54 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Wed, 04 Jan 2017 18:21:54 +1200
Subject: Hey, I'm new to python so don't judge.
Message-ID: <2025125030@f38.n261.z1.binkp.net>

On 1/3/2017 10:15 PM, Dennis Lee Bieber wrote:

> And that statement tells us you are trying to run from within some
> IDE/editor which is trapping Python exceptions and producing a dialog
> box for them.

IDLE does this when one runs code from the editor, because it
cannot/should not inject error messages into the editor buffer... AND it 
replaces the ^ with red highlighting of the code pointed to.  No
information is lost.  Apparently, some beginners do not see the connection 
between the SyntaxError box and the red highlighting.  I think I should add 
something to the box.  Maybe 'The error was detected at the point of the red 
highlighting.'

> Instead, save your script (if you haven't yet) as a file
> (whatever.py).
>
> Open a command line interpreter/shell.
>
> Navigate (cd ...) to where you saved the file
>
> Type "python whatever.py"

What a nuisance.

> Copy and paste the results of the CLI/Shell window.

Or one can hit F5 to run the code or Alt-X to just check the syntax. A beginner 
should do this every few lines, and it should be as easy as possible to check.  
If one needs to ask about a syntax error, one can copy the code up and 
including the highlighted part. Example:

"When I run this code in IDLE

def is_same(target, number:
         if

I get a SyntaxError at 'if'."

If the OP had known to do this, the error might have been seen without posting.

--
Terry Jan Reedy



From orgnut at yahoo.com  Wed Jan  4 01:27:11 2017
From: orgnut at yahoo.com (Larry Hudson)
Date: Tue, 3 Jan 2017 22:27:11 -0800
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <40adacf3-b4de-4243-8cb5-6ea5fb74cf18@googlegroups.com>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <CAPTjJmrwnjd+em2beKAYyZAe6k6EJg4xO2Brzg=BOUzG+SFE3Q@mail.gmail.com>
 <cc7ace5b-46ca-0727-2be6-a173f89e9df1@lucidity.plus.com>
 <CAPTjJmo=1+bQe-2OMOwikJj11ziQVm0fZKBeHEeTMbo718YBFw@mail.gmail.com>
 <mailman.184.1483489020.2395.python-list@python.org>
 <40adacf3-b4de-4243-8cb5-6ea5fb74cf18@googlegroups.com>
Message-ID: <zNGdnVzIvKIuCPHFnZ2dnUU7-aXNnZ2d@giganews.com>

On 01/03/2017 04:27 PM, Callum Robinson wrote:
> On Wednesday, January 4, 2017 at 1:17:11 PM UTC+13, Chris Angelico wrote:
>> On Wed, Jan 4, 2017 at 11:03 AM, Erik <python at lucidity.plus.com> wrote:
>>> I doubt it's getting that far (I can see at least one syntax error in the
>>> code pasted).
>>
>> True true. In any case, the point is to copy and paste the error
>> message. Callum, please, copy and paste it.
>>
>> ChrisA
>
> I'm sorry if I'm doing something wrong but all that is happening is when i try to run it a popup says Invalid syntax
>

Exactly HOW are you running this?

If you are getting a popup, I suspect you are using an on-line version in a browser.  To get the 
proper Python error messages (called Tracebacks) you MUST run the program in a terminal on your 
own computer.  These tracebacks are VERY informative (once you get used to them).   :-)
And these tracebacks are what WE need to see to help you.

You DO have Python installed, don't you?

-- 
      -=- Larry -=-


From rosuav at gmail.com  Wed Jan  4 01:27:32 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 04 Jan 2017 18:27:32 +1200
Subject: Mutable global state and threads
Message-ID: <2586819455@f38.n261.z1.binkp.net>

On Wed, Jan 4, 2017 at 5:41 PM, Kev Dwyer <kevin.p.dwyer at gmail.com> wrote:
> Hello List,
>
> I came across some threading code in Some Other place recently and wanted to
> sanity-check my assumptions.
>
> The code (below) creates a number of threads; each thread takes the last
> (index -1) value from a global list of integers, increments it by one and
> appends the new value to the list.
>
> The originator of the code expected that when all the threads completed, the
> list would be an ascending sequence of integers, for example if the original
> list was [0] and two threads mutated it twice each, the final state would be
> [0, 1, 2, 3, 4].
>
> Here is a version of the code (slightly simplified and modified to allow
> changing the number of threads and mutations).
>
>
> import sys
> import threading
>
>
> class myThread(threading.Thread):
>
>     def __init__(self, nmutations):
>         threading.Thread.__init__(self)
>         self.nmutations = nmutations
>
>     def run(self):
>         mutate(self.nmutations)
>         # print (L)
>         return
>
> def mutate(nmutations):
>     n = nmutations
>     while n:
>         L.append(L[-1 ]+ 1)
>         n -= 1
>     return
>
>
> def main(nthreads=2, nmutations=2):
>     global L
>     L = [0]
>     threads = [myThread(nmutations) for i in range(nthreads)]

You can drop the myThread class and instead instantiate threading.Thread 
directly:

threads = [threading.Thread(target=mutate, args=(nmutations,))
    for i in range(nthreads)]
> Firstly, is it true that the statement
>
> L.append(L[-1 ]+ 1)
>
> is not atomic, that is the thread might evaluate L[-1] and then yield,
> allowing another thread to mutate L, before incrementing and appending?

That is indeed true. If the code were all run sequentially (setting nthreads to 
1), the last element in the final list would be equal to nthreads*nmutations, 
and you can mess around with the numbers to find out exactly how far short it 
is.

Python guarantees that certain primitive operations (such as the list append 
itself) won't be broken, but anything that involves application code can be 
split up. So you can be confident that you'll end up with a list of integers 
and not a segfault, but they might not even be consecutive.

> Secondly, the original code printed the list at the end of a thread's run
> method to examine the state of the list.  I don't think this would work
> quite as expected, because the thread might yield after mutating the list
> but before printing, so the list could have been mutated before the print
> was executed.  Is there a way to display the state of the list before any
> further mutations take place?

At the end of one thread's run, there are other threads still running. So 
you're correct again; another thread could change the list. What you could 
possibly do mess with locking, but before I advise that, I'd have to see what 
you're trying to accomplish - toy examples are hard to mess with. Bear in mind 
that simple code like this can't actually benefit from threads, as Python (or 
at least, CPython) won't run two of them at once.

> (Disclaimer: I understand that sanity, mutable global state and threads are
> unlikely bedfellows and so promise never to try anything like this in
> production code).

Well, I lost my sanity shortly after becoming a programmer, so I've happily 
used mutable globals in threaded programs. :) You can use them quite happily as 
long as you know what you're doing. But if you find yourself tossing in heaps 
of locks to try to reclaim your sanity, you may want to consider asyncio 
instead. Instead of locking and unlocking to say "don't yield here", you 
explicitly say "yield here". The downside is that you have to have *everything* 
cope with that - and not everything can. (For a long time, it was easy to 
establish a socket connection asynchronously, but hard to look up 
"www.python.org" without potentially stalling.) They're two models that can 
both be used to solve a lot of the same problems.

By and large, your analysis is correct. Have fun threading! :)

ChrisA



From kevin.p.dwyer at gmail.com  Wed Jan  4 01:41:40 2017
From: kevin.p.dwyer at gmail.com (Kev Dwyer)
Date: Wed, 04 Jan 2017 06:41:40 +0000
Subject: Mutable global state and threads
Message-ID: <o4i5f1$ah$1@blaine.gmane.org>

Hello List,

I came across some threading code in Some Other place recently and wanted to 
sanity-check my assumptions.

The code (below) creates a number of threads; each thread takes the last 
(index -1) value from a global list of integers, increments it by one and 
appends the new value to the list.

The originator of the code expected that when all the threads completed, the 
list would be an ascending sequence of integers, for example if the original 
list was [0] and two threads mutated it twice each, the final state would be 
[0, 1, 2, 3, 4].

Here is a version of the code (slightly simplified and modified to allow 
changing the number of threads and mutations).


import sys
import threading


class myThread(threading.Thread):
    
    def __init__(self, nmutations):
        threading.Thread.__init__(self)
        self.nmutations = nmutations

    def run(self):
        mutate(self.nmutations)
        # print (L)
        return


def mutate(nmutations):
    n = nmutations
    while n:
        L.append(L[-1 ]+ 1)
        n -= 1
    return


def main(nthreads=2, nmutations=2):
    global L
    L = [0]
    threads = [myThread(nmutations) for i in range(nthreads)]
    for t in threads:
        t.start()
    for t in threads:
        t.join()
    print(L)
    assert L == list(range((nthreads * nmutations) + 1))

if __name__ == '__main__':
    nthreads, nmutations = int(sys.argv[1]), int(sys.argv[2])
    main(nthreads, nmutations)

Firstly, is it true that the statement

L.append(L[-1 ]+ 1)

is not atomic, that is the thread might evaluate L[-1] and then yield, 
allowing another thread to mutate L, before incrementing and appending?

Secondly, the original code printed the list at the end of a thread's run 
method to examine the state of the list.  I don't think this would work 
quite as expected, because the thread might yield after mutating the list 
but before printing, so the list could have been mutated before the print
was executed.  Is there a way to display the state of the list before any 
further mutations take place?

(Disclaimer: I understand that sanity, mutable global state and threads are 
unlikely bedfellows and so promise never to try anything like this in 
production code).

Cheers,

Kev





From gilmeh.serdah at nothing.here.invalid  Wed Jan  4 01:52:02 2017
From: gilmeh.serdah at nothing.here.invalid (Gilmeh Serda)
Date: Wed, 04 Jan 2017 18:52:02 +1200
Subject: Clickable hyperlinks
References: <1391343616@f38.n261.z1.binkp.net>
Message-ID: <612325293@f38.n261.z1.binkp.net>

On Tue, 03 Jan 2017 11:46:16 -0800, Deborah Swanson wrote:

> Does python have an equivalent function? Probably the most common use
> for it would be output to the console, similar to a print statement, but
> clickable.

Write it as HTML code save to temp file and call the browser which loads the 
file.

--
Gilmeh



From tonycamgar at gmail.com  Wed Jan  4 01:54:11 2017
From: tonycamgar at gmail.com (Antonio Caminero Garcia)
Date: Tue, 3 Jan 2017 22:54:11 -0800 (PST)
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <mailman.183.1483488743.2395.python-list@python.org>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
 <64837604-9f3a-806c-d631-fcc352738952@schwertberger.de>
 <mailman.183.1483488743.2395.python-list@python.org>
Message-ID: <04dc51b5-d546-427f-8ad2-d69284682bdf@googlegroups.com>

On Tuesday, January 3, 2017 at 4:12:34 PM UTC-8, Dietmar Schwertberger wrote:
> On 02.01.2017 12:38, Antonio Caminero Garcia wrote:
> You did not try Wing IDE? It looks less like a spacecraft. Maybe you 
> like it.
> Maybe the difference is that Wing is from Python people while the ones 
> you listed are from Java people.

That sounds interesting. By the look of it I think I am going to give it a try.

> For something completely different (microcontroller programming in C) I 
> just switched to a Eclipse derived IDE and I don't like it too much as 
> the tool does not focus on the problem scope.

If it happens to be Arduino I normally use a sublime plugin called Stino
https://github.com/Robot-Will/Stino 
(1337 people starred that cool number :D)

>  From your posts I'm not sure whether you want an editor or an IDE, 
> where for me the main difference is the debugger and code completion.

I want editor with those IDE capabilities and git integration, with optionally  cool stuff as for example remote debugging. 

> I would not want to miss the IDE features any more, even though in my 
> first 15 years of Python I thought that a debugger is optional with 
> Python ...

Unfortunately most of the time I am still using print and input functions. I know that sucks, I did not use the pdb module, I guess that IDE debuggers leverage such module.

> Regards,
> 
> Dietmar

Thank you so much for your answer. 



From tjreedy at udel.edu  Wed Jan  4 01:57:52 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Wed, 04 Jan 2017 18:57:52 +1200
Subject: Clickable hyperlinks
Message-ID: <3081631347@f38.n261.z1.binkp.net>

On 1/4/2017 4:32 AM, Deborah Swanson wrote:

> My original question was whether python had anything to provide this
> functionality, and the answer appears to be a resounding NO!!!

I would say 'Yes, but with user effort'.

To have a string interpreted as a clickable link, you send the string to 
software capable of creating a clickable link, plus the information
'this is a clickable link'*.  There are two ways to tag a string as a
link.  One is to use markup around the url in the string itself.
'<url>' and html are example.  Python provides multiple to make this
easy. The other is to tag the string with a separate argument.  Python provides 
tkinter, which wraps tk Text widgets, which have a powerful tag system.  One 
can define a Link tag that will a) cause text to be displayed, for instance, 
blue and underlined and b) cause clicks on the text to generate a web request.  
One could then use
   mytext.insert('insert', 'http://www.example.com', Link)
Browser must do something similar when they encounter when they encounter html 
link tags.

* If the software directly recognizes a bare url such as
'http://www.example.com' as a link, without further indication, then it
should have a way to disable conversion to a clickable link.

--
Terry Jan Reedy



From greg.ewing at canterbury.ac.nz  Wed Jan  4 02:00:10 2017
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Wed, 04 Jan 2017 19:00:10 +1200
Subject: Simulating int arithmetic with wrap-around
References: <3917850917@f38.n261.z1.binkp.net>
Message-ID: <1195249011@f38.n261.z1.binkp.net>

Paul Rubin wrote:
> My first thought is towards the struct module, especially if you want to
> handle a bunch of such integers at the same time.  Or maybe the array
> module or some combination.

Or possibly numpy.

--
Greg



From rustompmody at gmail.com  Wed Jan  4 02:22:28 2017
From: rustompmody at gmail.com (Rustom Mody)
Date: Wed, 04 Jan 2017 19:22:28 +1200
Subject: Clickable hyperlinks
References: <2359161402@f38.n261.z1.binkp.net>
Message-ID: <2761968576@f38.n261.z1.binkp.net>

This thread does lead to the question: Is the Url type in python less 
first-class than it could be?

In scheme I could point to something like this 
https://docs.racket-lang.org/net/url.html

Is there something equivalent in python?



From rosuav at gmail.com  Wed Jan  4 02:27:32 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 4 Jan 2017 18:27:32 +1100
Subject: Mutable global state and threads
In-Reply-To: <o4i5f1$ah$1@blaine.gmane.org>
References: <o4i5f1$ah$1@blaine.gmane.org>
Message-ID: <CAPTjJmqG2MvNmmXBOJtBe-gJqhBw=9joHsEfU8tcMr1uZy5DKA@mail.gmail.com>

On Wed, Jan 4, 2017 at 5:41 PM, Kev Dwyer <kevin.p.dwyer at gmail.com> wrote:
> Hello List,
>
> I came across some threading code in Some Other place recently and wanted to
> sanity-check my assumptions.
>
> The code (below) creates a number of threads; each thread takes the last
> (index -1) value from a global list of integers, increments it by one and
> appends the new value to the list.
>
> The originator of the code expected that when all the threads completed, the
> list would be an ascending sequence of integers, for example if the original
> list was [0] and two threads mutated it twice each, the final state would be
> [0, 1, 2, 3, 4].
>
> Here is a version of the code (slightly simplified and modified to allow
> changing the number of threads and mutations).
>
>
> import sys
> import threading
>
>
> class myThread(threading.Thread):
>
>     def __init__(self, nmutations):
>         threading.Thread.__init__(self)
>         self.nmutations = nmutations
>
>     def run(self):
>         mutate(self.nmutations)
>         # print (L)
>         return
>
> def mutate(nmutations):
>     n = nmutations
>     while n:
>         L.append(L[-1 ]+ 1)
>         n -= 1
>     return
>
>
> def main(nthreads=2, nmutations=2):
>     global L
>     L = [0]
>     threads = [myThread(nmutations) for i in range(nthreads)]

You can drop the myThread class and instead instantiate
threading.Thread directly:

threads = [threading.Thread(target=mutate, args=(nmutations,))
    for i in range(nthreads)]
> Firstly, is it true that the statement
>
> L.append(L[-1 ]+ 1)
>
> is not atomic, that is the thread might evaluate L[-1] and then yield,
> allowing another thread to mutate L, before incrementing and appending?

That is indeed true. If the code were all run sequentially (setting
nthreads to 1), the last element in the final list would be equal to
nthreads*nmutations, and you can mess around with the numbers to find
out exactly how far short it is.

Python guarantees that certain primitive operations (such as the list
append itself) won't be broken, but anything that involves application
code can be split up. So you can be confident that you'll end up with
a list of integers and not a segfault, but they might not even be
consecutive.

> Secondly, the original code printed the list at the end of a thread's run
> method to examine the state of the list.  I don't think this would work
> quite as expected, because the thread might yield after mutating the list
> but before printing, so the list could have been mutated before the print
> was executed.  Is there a way to display the state of the list before any
> further mutations take place?

At the end of one thread's run, there are other threads still running.
So you're correct again; another thread could change the list. What
you could possibly do mess with locking, but before I advise that, I'd
have to see what you're trying to accomplish - toy examples are hard
to mess with. Bear in mind that simple code like this can't actually
benefit from threads, as Python (or at least, CPython) won't run two
of them at once.

> (Disclaimer: I understand that sanity, mutable global state and threads are
> unlikely bedfellows and so promise never to try anything like this in
> production code).

Well, I lost my sanity shortly after becoming a programmer, so I've
happily used mutable globals in threaded programs. :) You can use them
quite happily as long as you know what you're doing. But if you find
yourself tossing in heaps of locks to try to reclaim your sanity, you
may want to consider asyncio instead. Instead of locking and unlocking
to say "don't yield here", you explicitly say "yield here". The
downside is that you have to have *everything* cope with that - and
not everything can. (For a long time, it was easy to establish a
socket connection asynchronously, but hard to look up "www.python.org"
without potentially stalling.) They're two models that can both be
used to solve a lot of the same problems.

By and large, your analysis is correct. Have fun threading! :)

ChrisA


From flebber.crue at gmail.com  Wed Jan  4 02:32:22 2017
From: flebber.crue at gmail.com (Sayth Renshaw)
Date: Wed, 04 Jan 2017 19:32:22 +1200
Subject: Is there a good process or library for validating changes to XML
 format
Message-ID: <2750102362@f38.n261.z1.binkp.net>

Afternoon

Is there a good library or way I could use to check that the author of the XML 
doc I am using doesn't make small changes to structure over releases?

Not fully over this with XML but thought that XSD may be what I need, if I 
search "python XSD" I get a main result for PyXB and generateDS 
(https://pythonhosted.org/generateDS/).

Both seem to be libraries for generating bindings to structures for parsing so 
maybe I am searching the wrong thing. What is the right thing to search?

Cheers

Sayth



From paul.nospam at rudin.co.uk  Wed Jan  4 03:04:45 2017
From: paul.nospam at rudin.co.uk (Paul Rudin)
Date: Wed, 04 Jan 2017 08:04:45 +0000
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
 <ba923722-087d-4c13-aaf6-0950a370c27b@googlegroups.com>
 <20170103191311.GB18910@mail.akwebsoft.com>
 <mailman.149.1483470792.2395.python-list@python.org>
Message-ID: <87wpeb45eq.fsf@rudin.co.uk>

Tim Johnson <tim at akwebsoft.com> writes:

> * Antonio Caminero Garcia <tonycamgar at gmail.com> [170102 20:56]:
>> Guys really thank you for your answers. Basically now I am more
>> emphasizing in learning in depth a tool and get stick to it so I
>> can get a fast workflow. Eventually I will learn Vim and its
>> python developing setup, I know people who have been programming
>> using Vim for almost 20 years and they did not need to change
>> editor (that is really awesome). 
>
>  Bye the way, one thing I like about the GUI based vim is that it
>  supports tabs, where emacs does not.

M-x package-install tabbar






From python at deborahswanson.net  Wed Jan  4 03:19:32 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 04 Jan 2017 20:19:32 +1200
Subject: Clickable hyperlinks
Message-ID: <2915184730@f38.n261.z1.binkp.net>

Chris Angelico wrote, on January 04, 2017 4:16 AM
>
> Yeah, there's no simple answer; however, you'll find that
> Python on many platforms is entirely capable of popping a URL
> up in the user's default browser. Check this out:
>
> >>> import antigravity

I downloaded the code from the Package Index, but there really wasn't much in 
it. This is the entire .py file:

STRIP_URL = "http://xkcd.com/353/"

def start():
    return STRIP_URL

And setup.py is equally disappointing: from distutils.core import setup

setup(
    name='antigravity',
    version='0.1',
    description='A really simple module that allow everyone to do
"import antigravity"',
    author='Fabien Schwob',
    author_email='antigravity at x-phuture.com',
    url='http://fabien.schwob.org/antigravity/',
    packages=['antigravity'],
)

> This uses the 'webbrowser' module, which knows about a number
> of different ways to open a browser, and will attempt them
> all. So if you can figure out the UI part of things, actually
> making the link pop up in a browser isn't too hard; for
> instance, if you're doing OAuth at the command line and need
> the user to go and authenticate, you can simply
> webbrowser.open("http://......./") and it'll DTRT.
>
> ChrisA

All the action of antigravity must be done by the import statement. When import 
opens a module that immediately returns a url, it must have a mechanism to open 
it in a browser.

It would be very easy to do the same thing with my own .py and import it into 
another .py.

Or, take a look at import's code and figure out how it opens a url in a 
browser. I imagine it's the 'webbrowser' module you mention. If it tries 
several methods, just pick one that will work for you.

Or, take a look at this Index of Packages Matching 'webbrowser' (~50 packages)
https://pypi.python.org/pypi?%3Aaction=search&term=webbrowser&submit=sea
rch

D'Arcy was right, there's lots in python that's internet aware, though that 
wasn't the question I knew to ask.



From paul.nospam at rudin.co.uk  Wed Jan  4 03:22:03 2017
From: paul.nospam at rudin.co.uk (Paul Rudin)
Date: Wed, 04 Jan 2017 08:22:03 +0000
Subject: Clickable hyperlinks
References: <586c7434$0$1617$c3e8da3$5496439d@news.astraweb.com>
 <00b301d26645$8553e490$27b23dae@sambora>
 <mailman.214.1483505156.2395.python-list@python.org>
Message-ID: <87mvf744lw.fsf@rudin.co.uk>

"Deborah Swanson" <python at deborahswanson.net> writes:

>
> I didn't try printing them before, but I just did. Got:
>
>>>> print([Example](http://www.example.com)
>       
> SyntaxError: invalid syntax  (arrow pointing at the colon)
>  

With respect, if you typed that at python then it's probably a good idea
to take a step back and work through the excellent tutorial.

https://docs.python.org/3/tutorial/



From wlfraed at ix.netcom.com  Wed Jan  4 03:41:06 2017
From: wlfraed at ix.netcom.com (Dennis Lee Bieber)
Date: Wed, 04 Jan 2017 20:41:06 +1200
Subject: Clickable hyperlinks
Message-ID: <3269602639@f38.n261.z1.binkp.net>

On Wed, 4 Jan 2017 14:58:42 -0800, "Deborah Swanson"
<python at deborahswanson.net> declaimed the following:

>Thank you, thank you! Finally, at least one person on this list knows
>about something (anything) in the python world that is internet aware.
>It's also occurred to me that Beautifulsoup downloads data from a url,
>so that code must have access to some kind of an internet engine too.
>

        Uhm... There is a big difference between "clickable links" and
"internet aware".

        Look at the Library reference manual. There is a section on "Internet
Data Handling", and another on "Internet Protocols and Support". For just 
retrieving things identified by a URL, there are both urllib and urllib2; and 
for more specific there is httplib, ftplib, poplib, etc.


        Clickable links is a user interface matter -- and as mentioned numerous
times, depends upon the features of the interface, not of Python (unless you 
are writing a full-fledged GUI application in which case you have to tag 
entities as clickable and handle the user clicking on that entity, followed by 
actually using one of the above library routines to fetch the contents at the 
clickable's target)

--
        Wulfraed                 Dennis Lee Bieber         AF6VN
    wlfraed at ix.netcom.com    HTTP://wlfraed.home.netcom.com/



From steve+python at pearwood.info  Wed Jan  4 03:41:52 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 20:41:52 +1200
Subject: Screwing Up looping in Generator
References: <1791039168@f38.n261.z1.binkp.net>
Message-ID: <1214507658@f38.n261.z1.binkp.net>

On Wed, 4 Jan 2017 01:09 pm, Sayth Renshaw wrote:

> Untested as i wrote this in notepad at work but, if i first use the
> generator to create a set of filenames and then iterate it then call the
> generator anew to process file may work?

It "may" work. Or it "may not" work. It is hard to tell because we don't have 
enough context to understand your code.

Let me see if I can guess what you are doing:

> Good idea or better available?
>
> def get_list_of_names(generator_arg):
>     name_set = set()
>     for name in generator_arg:
>         base = os.path.basename(name.name)
>         filename = os.path.splitext(base)[0]
>         name_set.add(filename)
>     return name_set

What does "generator_arg" do? Since you iterate over it, it could be a list, a 
tuple, any other sequence, or an iterator. Why does it have to be a generator?

What is "name.name"?

I *think* that your intention is to take a list of objects that hold filenames:


["C://My Documents/data.txt", "C://My Documents/folder/image.jpg",
 "C://file.txt", "D://installer.exe", "E://folder/image.gif"]

strip off the path, strip off the file extensions, remove any duplicates, 
giving:

set(["data", "image", "file", "installer"])

(Notice that image.jpg and image.gif count as duplicates.)


If that is what you want, then I think get_list_of_names will work, except:

- the name is WRONG: it returns a set, not a list;

- the name does not describe what the function does;

- there's no documentation

- the name of the argument is misleading, it doesn't have to be a generator.


Other than that, I think the code does what I think you want.


>  for file_name in name_set:
>      directory = "output"
>          with open(os.path.join(directory, filename, 'w', newline='') as
>          csvf:
>             for file in rootobs:
>               # create and write csv


Your indentation is wrong.

What's "rootobs"?

The code you show here does not have enough detail for me to even try to guess 
what it does.





--
Steve
? ?Cheer up,? ? they said, ? ?things could be worse.? ? So I cheered up, and
sure
enough, things got worse.



From python at deborahswanson.net  Wed Jan  4 04:00:55 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 4 Jan 2017 01:00:55 -0800
Subject: Clickable hyperlinks
In-Reply-To: <03e6b340-fa99-cfe7-8c5d-ba2dcd0b7aa0@gmail.com>
Message-ID: <000001d26669$0fc31c90$27b23dae@sambora>

Michael Torrie wrote, on January 03, 2017 8:05 PM
> 
> On 01/03/2017 08:46 PM, Deborah Swanson wrote:
> > Actually it is, or at least it doesn't happen in all email readers. 
> > Mine, for instance, never breaks up threads.
> 
> Mine doesn't either, which illustrates the issue. This  
> message, for example appears under a long thread that started 
> out life as "mentor training python Romania with 
> certification" and then changed to "Cleaning up conditionals" 
> and then changed to "Clickable hyperlinks." All in one 
> thread. My client doesn't break them up because they all tie 
> together via the message-id header.
> 
> And most of us would not like our client to break a thread 
> just because the subject changes. Often in long conversations 
> there are twists and turns in the discussion and sometimes 
> side-paths are explored, and the subject often is changed to 
> reflect this.  With a truly threaded email reader (one that 
> shows a tree of messages, not just chronological order), this 
> works out very well.  So if a discussion has a natural 
> evolution into various other topics, it is often considered 
> okay to just change the subject but continue the thread. 
> Other times, it's better to start a new thread.  Where that 
> line is is hard to say!
> 
> > I did say in the message you're replying to that I will try to 
> > remember to start new threads with brand new messages. 
> (Even though I 
> > think pipermail's behavior is a bug, that's what many 
> people read the 
> > list
> > from.)
> 
> Sounds good.
> 
> I don't know of anyone that reads on the pipermail archive, 
> except in response to web searches.  Most people use clients 
> of some kind, NNTP or email.  And those that group messages 
> according to message-id (most clients except for ones that 
> try to be smart like Gmail web or Outlook) will show all the 
> topics I mentioned before as one giant thread, which is by 
> design (that's what message-id headers are for).

I suppose. Times change of course, which always suits some and not
others. Personally, I think putting messages that have different titles
all in one thread is a bad design, but as I've said a couple of times
now I intend to comply with the new rules. But compliance doesn't imply
agreement. I prefer the old system, which ordered threads by titles, but
there's obviously no pleasing everyone on this issue.  



From steve+python at pearwood.info  Wed Jan  4 04:08:52 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 21:08:52 +1200
Subject: Clickable hyperlinks
References: <759429036@f38.n261.z1.binkp.net>
Message-ID: <3354116128@f38.n261.z1.binkp.net>

On Wed, 4 Jan 2017 08:00 pm, Deborah Swanson wrote:

[speaking of threading emails]

> I suppose. Times change of course, which always suits some and not
> others. Personally, I think putting messages that have different titles
> all in one thread is a bad design, but as I've said a couple of times
> now I intend to comply with the new rules. But compliance doesn't imply
> agreement. I prefer the old system, which ordered threads by titles, but
> there's obviously no pleasing everyone on this issue.

Indeed :-)

However, as far as I am aware, the use of threading by following the 
In-Reply-To and References header lines goes back to at least 1982, which makes 
them pretty old, and certainly pre-dates Gmail and Outlook by many years. 
They're also official standards which ALL email programs are supposed to 
follow, so if Gmail and Outlook fail to follow the standard, well, I wouldn't 
be surprised. I don't absolutely know for a fact that threading in this way is 
older than threading by subject line, but I'm fairly confident that what you 
are calling the "new rules" are actually the much older rules.

Are there any old-timers here who were using email prior to 1982 that would 
care to comment?


Here's a discussion by Jamie Zawinski, who wrote Netscape Navigator, before it 
became Mozila and Firefox, so he knows what he's talking about:

https://www.jwz.org/doc/threading.html


The concept here is not so much that people start a new topic and change the 
subject, but that sometimes the topic just naturally evolves to the point that 
a change in subject is sensible. Take this thread for example: the topic has 
drifted from "Clickable hyperlinks" to talking about email threading. I should 
be able to change the subject without breaking the thread:

Clickable hyperlinks
?????  RE: Clickable hyperlinks
???  ?????  Re: RE: Clickable hyperlinks
???  ?????  RE: Clickable hyperlinks
???     ?????  Threading [was Re: Clickable hyperlinks]
???        ?????  Re: Threading
?????  RE: Clickable hyperlinks
?????  Re: Clickable hyperlinks


Adding a "Re:" or "RE" to the subject doesn't change the thread, and neither 
does changing the subject line in a more substantial way.

Of course, I can always *choose* to sort by subject line, or date. Personally I 
hardly ever sort by thread, so it is no skin off my nose what you do. But when 
you hit "Reply" to a message, you inherit the "Reference" and "In-Reply-To" 
headers from the previous message, so at least some people will see it threaded 
in an existing thread rather than starting a brand new one.




--
Steve
? ?Cheer up,? ? they said, ? ?things could be worse.? ? So I cheered up, and
sure
enough, things got worse.



From steve+python at pearwood.info  Wed Jan  4 04:20:28 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 21:20:28 +1200
Subject: Clickable hyperlinks
References: <973176847@f38.n261.z1.binkp.net>
Message-ID: <3543245575@f38.n261.z1.binkp.net>

On Wed, 4 Jan 2017 03:46 pm, Deborah Swanson wrote:

> As I've mentioned in other posts on this thread, I'm now thinking that I
> need to write a class to do this, and find out how Firefox and url aware
> terminals in Linux do it. There must be a way.


A GUI application can interpret text any way it chooses. Firefox takes a HTML 
file and renders it, using whatever GUI library it chooses. That GUI
library understands that text like:

<b>Hello World!</b>

should be shown in bold face, and text like:

<a href="http://www.example.com">Example</a>

should be shown as the word "Example" underlined and in some colour, and when 
you click on it the browser will navigate to the URL given. Firefox can do this 
because it controls the environment it runs in.

Same for Excel, which also controls the environment it runs in.

That's *not* the case for Python, which is at the mercy of whatever console or 
terminal application it is running in.

However, you can use Python to write GUI applications. Then it becomes
*your* responsibility to create the window, populate it with any buttons or
text or scroll bars you want, and you can choose to interpret text any way you 
like -- including as clickable Hyperlinks.

The bottom line is, there is no "a way" to do this. There are a thousand, ten 
thousand, ways to do it. Every web browser, every terminal, every URL-aware 
application, can choose its own way to do it. There's no one
single way that works everywhere, but if you are working in a console or 
terminal, just printing the URL is likely to be interpreted by the console as a 
clickable link:

print("http://www.example.com")




--
Steve
? ?Cheer up,? ? they said, ? ?things could be worse.? ? So I cheered up, and
sure
enough, things got worse.



From python at deborahswanson.net  Wed Jan  4 04:32:12 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 4 Jan 2017 01:32:12 -0800
Subject: Clickable hyperlinks
In-Reply-To: <586c8ab3$0$1506$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <000601d2666d$6e7eae30$27b23dae@sambora>

Steven D'Aprano wrote, on January 03, 2017 9:40 PM
> 
> On Wednesday 04 January 2017 15:46, Deborah Swanson wrote:
> 
> > Steven D'Aprano wrote, on January 03, 2017 8:04 PM
> [...]
> >> Of course you have to put quotes around them to enter them in your 
> >> source code. We don't expect this to work:
> >> 
> >>     print(Hello World!)
> >> 
> >> 
> >> you have to use a string literal with quotes:
> >> 
> >>     print('Hello World!')
> >> 
> >> 
> >> Same for all of the above.
> 
> > I didn't try printing them before, but I just did. Got:
> > 
> >>>> print([Example](http://www.example.com)
> >       
> > SyntaxError: invalid syntax  (arrow pointing at the colon)
> 
> You missed the part where I said you have to put them in quotes.
> 
> Like any other string in Python, you have to use quotation 
> marks around it for 
> Python to understand it as a string. None of these things will work:
> 
> print( Hello World! )
> 
> print( What do you want to do today? )
> 
> print( 3 2 1 blast off )
> 
> print( http://www.example.com )
> 
> 
> This isn't specific to print. This won't work either:
> 
> message = Hello World!
> 
> In *all* of these cases, you have to tell Python you're 
> dealing with a string, 
> and you do that with quotation marks:
> 
> message = "Hello World!"
> print( 'What do you want to do today?' )
> count_down = '3 2 1 blast off'
> url = 'http://www.example.com'
> 
> 
> 
> 
> -- 
> Steven

Thanks, Steven. Yes, of course if you want to print strings you must
enclose them in quotes. I think you learn that in Week 1 of any
introductory course on Python.

But we aren't trying to print strings here, the point is to produce
clickable links. I didn't enclose them with quotes because I didn't see
any point in printing plain text when I wanted clickable links. I
actually didn't understand why you thought I should print them, but it
never would have occurred to me that you wanted me to print out a bunch
of silly plain text strings, apparently just for the heck of it.

At this point, if I pursue this any farther, it will be to look into how
Firefox takes webpage titles and urls out of its sqlite database and
makes objects you can click on to open the webpages. That's the basic
technology I'd need to find a way to talk (write) python into doing. 

If it's even worth it. On a practical level it's not worth it, way too
much work for the teensy advantage of having it to use. It might be some
giggles to figure out how to do it and maybe I will sometime just for
funsies.

My original question was whether python had anything to provide this
functionality, and the answer appears to be a resounding NO!!!

Answer received, and thanks to all who contributed.



From steve+python at pearwood.info  Wed Jan  4 04:39:14 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 21:39:14 +1200
Subject: Clickable hyperlinks
References: <4225562807@f38.n261.z1.binkp.net>
Message-ID: <2175282048@f38.n261.z1.binkp.net>

On Wed, 4 Jan 2017 08:32 pm, Deborah Swanson wrote:

> Thanks, Steven. Yes, of course if you want to print strings you must
> enclose them in quotes. I think you learn that in Week 1 of any
> introductory course on Python.
>
> But we aren't trying to print strings here, the point is to produce
> clickable links. I didn't enclose them with quotes because I didn't see
> any point in printing plain text when I wanted clickable links. I
> actually didn't understand why you thought I should print them, but it
> never would have occurred to me that you wanted me to print out a bunch
> of silly plain text strings, apparently just for the heck of it.

What we have here is a failure to communicate :-)

I apologise for ruffling your feathers, but its difficult to judge another 
person's level of knowledge. In someways you're obviously quite knowledgeable 
about Python, but in other ways you're still learning (as we all are!) and I'm 
afraid I may have misjudged exactly what your level of knowledge was. Sorry 
about that.

I'm not suggesting that you print "silly plain text strings" just for the heck 
of it. You've asked how to get a clickable link using Python. There is only one 
way I know of to get a clickable link using Python:

Write out a link as plain text to another application which then interprets the 
plain text as a clickable link.

You *might* be able to get clickable links in Python by writing an entire GUI 
application, using (say) the tkinter library, or one of the third-party
GUI libraries like wxPython, kivy, pyqt, or others, but I haven't a clue
how. But even there, your links will start off as text, which means you will 
still need to surround them with quotes to make them strings.


Aside: you've actually raised a fascinating question. I wonder whether there 
are any programming languages that understand URLs as native data types, so 
that *source code* starting with http:// etc is understood in the same way that 
source code starting with [ is seen as a list or { as a dict?


But back to your problem: short of writing you own GUI application, in which 
case you can do *anything you like*, you can:

- write out a HTML file containing the URLs you want, in <a href= ... </a>
tags, then open the HTML file in a web browser and let the web browser 
interpret the HTML tags as clickable links;


- write out an Excel spreadsheet, using whatever format Excel expects, open
the spreadsheet in Excel, and let Excel interpret the mystery format as a 
clickable link;

- print the URL to the console, and see if the console is smart enough to
interpret it as a clickable link.


I'm sorry that I can't give you a one-sentence answer "just use such-and-such a 
function, that does exactly what you want in a platform-independent manner" :-(




--
Steve
? ?Cheer up,? ? they said, ? ?things could be worse.? ? So I cheered up, and
sure
enough, things got worse.



From steve+python at pearwood.info  Wed Jan  4 04:41:53 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 20:41:53 +1100
Subject: Screwing Up looping in Generator
References: <009201d26627$9aee9390$27b23dae@sambora>
 <aa968655-9d16-b02f-bd7f-31ad8dc7d651@lucidity.plus.com>
 <mailman.195.1483493141.2395.python-list@python.org>
 <dc1a0766-2305-4c56-a0c0-d8418f9b0a02@googlegroups.com>
 <1e433232-7db7-4f1c-8637-50a3da469b20@googlegroups.com>
 <08c82541-86f7-4811-abeb-1205d2064506@googlegroups.com>
Message-ID: <586cc362$0$1606$c3e8da3$5496439d@news.astraweb.com>

On Wed, 4 Jan 2017 01:09 pm, Sayth Renshaw wrote:

> Untested as i wrote this in notepad at work but, if i first use the
> generator to create a set of filenames and then iterate it then call the
> generator anew to process file may work?

It "may" work. Or it "may not" work. It is hard to tell because we don't
have enough context to understand your code.

Let me see if I can guess what you are doing:

> Good idea or better available?
> 
> def get_list_of_names(generator_arg):
>     name_set = set()
>     for name in generator_arg:
>         base = os.path.basename(name.name)
>         filename = os.path.splitext(base)[0]
>         name_set.add(filename)
>     return name_set

What does "generator_arg" do? Since you iterate over it, it could be a list,
a tuple, any other sequence, or an iterator. Why does it have to be a
generator?

What is "name.name"?

I *think* that your intention is to take a list of objects that hold
filenames:


["C://My Documents/data.txt", "C://My Documents/folder/image.jpg",
 "C://file.txt", "D://installer.exe", "E://folder/image.gif"]

strip off the path, strip off the file extensions, remove any duplicates,
giving:

set(["data", "image", "file", "installer"])

(Notice that image.jpg and image.gif count as duplicates.)


If that is what you want, then I think get_list_of_names will work, except:

- the name is WRONG: it returns a set, not a list;

- the name does not describe what the function does;

- there's no documentation

- the name of the argument is misleading, it doesn't have to be a generator.


Other than that, I think the code does what I think you want.


>  for file_name in name_set:
>      directory = "output"
>          with open(os.path.join(directory, filename, 'w', newline='') as
>          csvf:
>             for file in rootobs:
>               # create and write csv


Your indentation is wrong.

What's "rootobs"?

The code you show here does not have enough detail for me to even try to
guess what it does. 





-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From maillist at schwertberger.de  Wed Jan  4 04:44:44 2017
From: maillist at schwertberger.de (Dietmar Schwertberger)
Date: Wed, 04 Jan 2017 21:44:44 +1200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
Message-ID: <4239897872@f38.n261.z1.binkp.net>

On 04.01.2017 15:41, William Ray Wing wrote:
> I use Wing, and I think you will like it.  It *is* pythonic, and for what it
is worth, offers remote debugging as one of its more recently added features. 
Obviously, you had no other choice than using Wing ;-)

The remote debugging has been around for some years. I have been using it quite 
often to debug on my Raspberry Pi, Nokia N900 and Jolla Phone, all running some 
Linux system. It works well. It is or was a bit complicated to set up. I think 
this has been improved with Wing 6, but I did not need it in the last weeks, so 
I don't know.

Regards,

Dietmar



From darcy at vex.net  Wed Jan  4 05:00:08 2017
From: darcy at vex.net (D'Arcy Cain)
Date: Wed, 04 Jan 2017 22:00:08 +1200
Subject: Clickable hyperlinks
Message-ID: <1485144662@f38.n261.z1.binkp.net>

On 2017-01-04 05:58 PM, Deborah Swanson wrote:
>> the user to go and authenticate, you can simply
>> webbrowser.open("http://......./") and it'll DTRT.
>
> Thank you, thank you! Finally, at least one person on this list knows
> about something (anything) in the python world that is internet aware.

Lots of things in Python are Internet aware.  That's not the question you asked 
though.

> It's also occurred to me that Beautifulsoup downloads data from a url,
> so that code must have access to some kind of an internet engine too.

Nope.  You have to feed it HTML.  You either need to generate that or capture 
it from somewhere.

--
D'Arcy J.M. Cain
System Administrator, Vex.Net
http://www.Vex.Net/ IM:darcy at Vex.Net VoIP: sip:darcy at Vex.Net



From steve+python at pearwood.info  Wed Jan  4 05:08:52 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 21:08:52 +1100
Subject: Clickable hyperlinks
References: <03e6b340-fa99-cfe7-8c5d-ba2dcd0b7aa0@gmail.com>
 <000001d26669$0fc31c90$27b23dae@sambora>
 <mailman.219.1483520417.2395.python-list@python.org>
Message-ID: <586cc9b5$0$1590$c3e8da3$5496439d@news.astraweb.com>

On Wed, 4 Jan 2017 08:00 pm, Deborah Swanson wrote:

[speaking of threading emails]

> I suppose. Times change of course, which always suits some and not
> others. Personally, I think putting messages that have different titles
> all in one thread is a bad design, but as I've said a couple of times
> now I intend to comply with the new rules. But compliance doesn't imply
> agreement. I prefer the old system, which ordered threads by titles, but
> there's obviously no pleasing everyone on this issue.

Indeed :-)

However, as far as I am aware, the use of threading by following the
In-Reply-To and References header lines goes back to at least 1982, which
makes them pretty old, and certainly pre-dates Gmail and Outlook by many
years. They're also official standards which ALL email programs are
supposed to follow, so if Gmail and Outlook fail to follow the standard,
well, I wouldn't be surprised. I don't absolutely know for a fact that
threading in this way is older than threading by subject line, but I'm
fairly confident that what you are calling the "new rules" are actually the
much older rules.

Are there any old-timers here who were using email prior to 1982 that would
care to comment?


Here's a discussion by Jamie Zawinski, who wrote Netscape Navigator, before
it became Mozila and Firefox, so he knows what he's talking about:

https://www.jwz.org/doc/threading.html


The concept here is not so much that people start a new topic and change the
subject, but that sometimes the topic just naturally evolves to the point
that a change in subject is sensible. Take this thread for example: the
topic has drifted from "Clickable hyperlinks" to talking about email
threading. I should be able to change the subject without breaking the
thread:

Clickable hyperlinks
?? RE: Clickable hyperlinks
?  ?? Re: RE: Clickable hyperlinks
?  ?? RE: Clickable hyperlinks
?     ?? Threading [was Re: Clickable hyperlinks]
?        ?? Re: Threading
?? RE: Clickable hyperlinks
?? Re: Clickable hyperlinks


Adding a "Re:" or "RE" to the subject doesn't change the thread, and neither
does changing the subject line in a more substantial way.

Of course, I can always *choose* to sort by subject line, or date.
Personally I hardly ever sort by thread, so it is no skin off my nose what
you do. But when you hit "Reply" to a message, you inherit the "Reference"
and "In-Reply-To" headers from the previous message, so at least some
people will see it threaded in an existing thread rather than starting a
brand new one.




-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From maillist at schwertberger.de  Wed Jan  4 05:09:30 2017
From: maillist at schwertberger.de (Dietmar Schwertberger)
Date: Wed, 04 Jan 2017 22:09:30 +1200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
Message-ID: <2715841046@f38.n261.z1.binkp.net>

On 04.01.2017 07:54, Antonio Caminero Garcia wrote:
> Unfortunately most of the time I am still using print and input functions. I
know that sucks, I did not use the pdb module, I guess that IDE debuggers 
leverage such module.
pdb is actually quite useful. On my Windows PCs I can invoke python on any .py 
file with the -i command line switch by right clicking in the Explorer and 
selecting "Debug". Now when the script crashes, I can inspect variables without 
launching a full-scale IDE or starting the script from the command line. For 
such quick fixes I have also a context menu entry "Edit" for editing with 
Pythonwin, which is still quite OK as editor and has no licensing restrictions 
or installation requirements. This is a nice option when you deploy your 
installation to many PCs over the network.

For the print functions vs. debugger: The most useful application for a 
debugger like Wing is not for bug-fixing, but to set a break point and then 
interactively develop on the debugger console and with the IDE editor's 
autocompletion using introspection on the live objects. This is very helpful 
for hardware interfacing, network protocols or GUI programs. It really boosted 
my productivity in a way I could not believe before. This is something most 
people forget when they evaluate programming languages. It's not the language 
or syntax that counts, but the overall environment. Probably the only other 
really interactive language and environment is Forth.

> If it happens to be Arduino I normally use a sublime plugin called Stino
> https://github.com/Robot-Will/Stino
> (1337 people starred that cool number :D)
Well, it is CodeWarrior which was quite famous at the time of the 68k Macs. The 
company was bought by Motorola and the IDE is still around for 
Freescale/NXP/Qualcomm microcontrollers like the HCS08 8 bit series. Around ten 
years ago the original CodeWarrior IDE was migrated to something Eclipse based.
When I last evaluated HCS08 vs. Arduino, the HCS08 won due to the better debug 
interface and native USB support. HCS08 is still quite cool, but when it comes 
to documentation, learning curve, tools etc. the Arduinos win....


Regards,

Dietmar



From steve+python at pearwood.info  Wed Jan  4 05:20:28 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 21:20:28 +1100
Subject: Clickable hyperlinks
References: <586c7434$0$1617$c3e8da3$5496439d@news.astraweb.com>
 <00b301d26645$8553e490$27b23dae@sambora>
 <mailman.214.1483505156.2395.python-list@python.org>
Message-ID: <586ccc6d$0$1596$c3e8da3$5496439d@news.astraweb.com>

On Wed, 4 Jan 2017 03:46 pm, Deborah Swanson wrote:

> As I've mentioned in other posts on this thread, I'm now thinking that I
> need to write a class to do this, and find out how Firefox and url aware
> terminals in Linux do it. There must be a way.


A GUI application can interpret text any way it chooses. Firefox takes a
HTML file and renders it, using whatever GUI library it chooses. That GUI
library understands that text like:

<b>Hello World!</b>

should be shown in bold face, and text like:

<a href="http://www.example.com">Example</a>

should be shown as the word "Example" underlined and in some colour, and
when you click on it the browser will navigate to the URL given. Firefox
can do this because it controls the environment it runs in.

Same for Excel, which also controls the environment it runs in.

That's *not* the case for Python, which is at the mercy of whatever console
or terminal application it is running in.

However, you can use Python to write GUI applications. Then it becomes
*your* responsibility to create the window, populate it with any buttons or
text or scroll bars you want, and you can choose to interpret text any way
you like -- including as clickable Hyperlinks.

The bottom line is, there is no "a way" to do this. There are a thousand,
ten thousand, ways to do it. Every web browser, every terminal, every
URL-aware application, can choose its own way to do it. There's no one
single way that works everywhere, but if you are working in a console or
terminal, just printing the URL is likely to be interpreted by the console
as a clickable link:

print("http://www.example.com")




-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From darcy at vex.net  Wed Jan  4 05:24:34 2017
From: darcy at vex.net (D'Arcy Cain)
Date: Wed, 04 Jan 2017 22:24:34 +1200
Subject: Clickable hyperlinks
Message-ID: <572149747@f38.n261.z1.binkp.net>

On 2017-01-04 07:07 PM, Deborah Swanson wrote:
> D'Arcy Cain wrote, on Wednesday, January 04, 2017 5:03 AM
>> In all the messages in this thread I still don't understand what this
>> "teensy advantage" is supposed to be.  Do you want to be able
>> to do this:
>>
>>    make_web_link(http://...)
>>
>> instead of:
>>
>>    make_web_link("http://...")

[...]

> Is make_web_link("http://...") valid python code? That's exactly the

It's just a made up name.  My point was that the first was syntactically 
incorrect and the second, while not a real method, was at least parseable.

I think I saw someone else mention this but it bears repeating.  When you ask a 
question make sure you are presenting the problem and not your solution to a 
secret problem.  Always tell us the actual problem you are trying to solve.  
You will get much better answers.

Think of it this way.  You drop a ring down a drain.  You can ask two 
questions, "How do I remove a drain trap?" or "How do I recover a ring that I 
dropped down the drain?"  If you ask the first question you will get lots of 
advice on tools and buckets, etc.  People will assume that the drain is 
blocked.  Ask the second question and someone might mention a magnet and a 
piece of string.

--
D'Arcy J.M. Cain
System Administrator, Vex.Net
http://www.Vex.Net/ IM:darcy at Vex.Net VoIP: sip:darcy at Vex.Net



From steve+python at pearwood.info  Wed Jan  4 05:39:15 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 04 Jan 2017 21:39:15 +1100
Subject: Clickable hyperlinks
References: <586c8ab3$0$1506$c3e8da3$5496439d@news.astraweb.com>
 <000601d2666d$6e7eae30$27b23dae@sambora>
 <mailman.220.1483522295.2395.python-list@python.org>
Message-ID: <586cd0d5$0$1595$c3e8da3$5496439d@news.astraweb.com>

On Wed, 4 Jan 2017 08:32 pm, Deborah Swanson wrote:

> Thanks, Steven. Yes, of course if you want to print strings you must
> enclose them in quotes. I think you learn that in Week 1 of any
> introductory course on Python.
> 
> But we aren't trying to print strings here, the point is to produce
> clickable links. I didn't enclose them with quotes because I didn't see
> any point in printing plain text when I wanted clickable links. I
> actually didn't understand why you thought I should print them, but it
> never would have occurred to me that you wanted me to print out a bunch
> of silly plain text strings, apparently just for the heck of it.

What we have here is a failure to communicate :-)

I apologise for ruffling your feathers, but its difficult to judge another
person's level of knowledge. In someways you're obviously quite
knowledgeable about Python, but in other ways you're still learning (as we
all are!) and I'm afraid I may have misjudged exactly what your level of
knowledge was. Sorry about that.

I'm not suggesting that you print "silly plain text strings" just for the
heck of it. You've asked how to get a clickable link using Python. There is
only one way I know of to get a clickable link using Python:

Write out a link as plain text to another application which then interprets
the plain text as a clickable link.

You *might* be able to get clickable links in Python by writing an entire
GUI application, using (say) the tkinter library, or one of the third-party
GUI libraries like wxPython, kivy, pyqt, or others, but I haven't a clue
how. But even there, your links will start off as text, which means you
will still need to surround them with quotes to make them strings.


Aside: you've actually raised a fascinating question. I wonder whether there
are any programming languages that understand URLs as native data types, so
that *source code* starting with http:// etc is understood in the same way
that source code starting with [ is seen as a list or { as a dict?


But back to your problem: short of writing you own GUI application, in which
case you can do *anything you like*, you can:

- write out a HTML file containing the URLs you want, in <a href= ... </a>
tags, then open the HTML file in a web browser and let the web browser
interpret the HTML tags as clickable links;


- write out an Excel spreadsheet, using whatever format Excel expects, open
the spreadsheet in Excel, and let Excel interpret the mystery format as a
clickable link;

- print the URL to the console, and see if the console is smart enough to
interpret it as a clickable link.


I'm sorry that I can't give you a one-sentence answer "just use
such-and-such a function, that does exactly what you want in a
platform-independent manner" :-(




-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From hpj at urpla.net  Wed Jan  4 06:15:02 2017
From: hpj at urpla.net (Hans-Peter Jansen)
Date: Wed, 04 Jan 2017 23:15:02 +1200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
Message-ID: <1885822774@f38.n261.z1.binkp.net>

On Montag, 2. Januar 2017 03:38:53 Antonio Caminero Garcia wrote:
> Hello, I am having a hard time deciding what IDE or IDE-like code editor
> should I use. This can be overwhelming.
>
> So far, I have used Vim, Sublime, Atom, Eclipse with PyDev, Pycharm,
> IntelliJ with Python plugin.

Well, since nobody mentioned it, yet: eric is doing quite nice here. With on 
the fly error checking, jedi and qscintilla calltips and autocompletion, git 
integration (using a plugin), graphical debugger, it's grown to a capable IDE 
over the years.

Given, it's a fully open source, PyQt based project, it also shows the powers 
of Python3 and PyQt.

Pete



From rosuav at gmail.com  Wed Jan  4 06:15:46 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 04 Jan 2017 23:15:46 +1200
Subject: Clickable hyperlinks
Message-ID: <3406130062@f38.n261.z1.binkp.net>

On Wed, Jan 4, 2017 at 10:43 PM, Deborah Swanson
<python at deborahswanson.net> wrote:
> I'm quite well aware by now that there is no one-sentence answer to my
> original question, if there's any coherent answer at all. Them's the
> breaks. Live with it or live without it, it doesn't care.

Yeah, there's no simple answer; however, you'll find that Python on many 
platforms is entirely capable of popping a URL up in the user's default 
browser. Check this out:

>>> import antigravity

This uses the 'webbrowser' module, which knows about a number of different ways 
to open a browser, and will attempt them all. So if you can figure out the UI 
part of things, actually making the link pop up in a browser isn't too hard; 
for instance, if you're doing OAuth at the command line and need the user to go 
and authenticate, you can simply webbrowser.open("http://......./") and it'll 
DTRT.

ChrisA



From python at deborahswanson.net  Wed Jan  4 06:15:52 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 4 Jan 2017 03:15:52 -0800
Subject: Clickable hyperlinks
In-Reply-To: <586cc9b5$0$1590$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <001201d2667b$e97c1740$27b23dae@sambora>

Steve D'Aprano wrote, on January 04, 2017 2:09 AM
> 
> On Wed, 4 Jan 2017 08:00 pm, Deborah Swanson wrote:
> 
> [speaking of threading emails]
> 
> > I suppose. Times change of course, which always suits some and not 
> > others. Personally, I think putting messages that have different 
> > titles all in one thread is a bad design, but as I've said 
> a couple of 
> > times now I intend to comply with the new rules. But compliance 
> > doesn't imply agreement. I prefer the old system, which ordered 
> > threads by titles, but there's obviously no pleasing 
> everyone on this 
> > issue.
> 
> Indeed :-)
> 
> However, as far as I am aware, the use of threading by 
> following the In-Reply-To and References header lines goes 
> back to at least 1982, which makes them pretty old, and 
> certainly pre-dates Gmail and Outlook by many years. They're 
> also official standards which ALL email programs are supposed 
> to follow, so if Gmail and Outlook fail to follow the 
> standard, well, I wouldn't be surprised. I don't absolutely 
> know for a fact that threading in this way is older than 
> threading by subject line, but I'm fairly confident that what 
> you are calling the "new rules" are actually the much older rules.
> 
> Are there any old-timers here who were using email prior to 
> 1982 that would care to comment?
> 
> 
> Here's a discussion by Jamie Zawinski, who wrote Netscape 
> Navigator, before it became Mozila and Firefox, so he knows 
> what he's talking about:
> 
https://www.jwz.org/doc/threading.html


The concept here is not so much that people start a new topic and change
the subject, but that sometimes the topic just naturally evolves to the
point that a change in subject is sensible. Take this thread for
example: the topic has drifted from "Clickable hyperlinks" to talking
about email threading. I should be able to change the subject without
breaking the
thread:

Clickable hyperlinks
+- RE: Clickable hyperlinks
?  +- Re: RE: Clickable hyperlinks
?  L- RE: Clickable hyperlinks
?     L- Threading [was Re: Clickable hyperlinks]
?        L- Re: Threading
+- RE: Clickable hyperlinks
L- Re: Clickable hyperlinks


Adding a "Re:" or "RE" to the subject doesn't change the thread, and
neither does changing the subject line in a more substantial way.

Of course, I can always *choose* to sort by subject line, or date.
Personally I hardly ever sort by thread, so it is no skin off my nose
what you do. But when you hit "Reply" to a message, you inherit the
"Reference" and "In-Reply-To" headers from the previous message, so at
least some people will see it threaded in an existing thread rather than
starting a brand new one.




-- 
Steve
"Cheer up," they said, "things could be worse." So I cheered up, and
sure enough, things got worse.

Interesting history lesson. I actually wouldn't know which came first,
since I've only been online since 1992 (offline computing since 1972). I
do know that I've been on a lot of mailing lists like this one since
1992 (remember Fidonet?), some with actively posting members in the
thousands. And I have never heard anyone whine and complain about
threading issues that had anything to do with the message title until
yesterday. 

So it goes. I'll repeat again that I'll comply with the rules of this
group that are brand spanking new to me, and I've been around a corner
or two.



From python at deborahswanson.net  Wed Jan  4 06:25:34 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 4 Jan 2017 03:25:34 -0800
Subject: Clickable hyperlinks
In-Reply-To: <586ccc6d$0$1596$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <001301d2667d$445ff450$27b23dae@sambora>

Steve D'Aprano wrote, on January 04, 2017 2:20 AM
> 
> On Wed, 4 Jan 2017 03:46 pm, Deborah Swanson wrote:
> 
> > As I've mentioned in other posts on this thread, I'm now 
> thinking that 
> > I need to write a class to do this, and find out how 
> Firefox and url 
> > aware terminals in Linux do it. There must be a way.
> 
> 
> A GUI application can interpret text any way it chooses. 
> Firefox takes a HTML file and renders it, using whatever GUI 
> library it chooses. That GUI library understands that text like:
> 
> <b>Hello World!</b>
> 
> should be shown in bold face, and text like:
> 
> <a href="http://www.example.com">Example</a>
> 
> should be shown as the word "Example" underlined and in some 
> colour, and when you click on it the browser will navigate to 
> the URL given. Firefox can do this because it controls the 
> environment it runs in.
> 
> Same for Excel, which also controls the environment it runs in.
> 
> That's *not* the case for Python, which is at the mercy of 
> whatever console or terminal application it is running in.
> 
> However, you can use Python to write GUI applications. Then it becomes
> *your* responsibility to create the window, populate it with 
> any buttons or text or scroll bars you want, and you can 
> choose to interpret text any way you like -- including as 
> clickable Hyperlinks.
> 
> The bottom line is, there is no "a way" to do this. There are 
> a thousand, ten thousand, ways to do it. Every web browser, 
> every terminal, every URL-aware application, can choose its 
> own way to do it. There's no one single way that works 
> everywhere, but if you are working in a console or terminal, 
> just printing the URL is likely to be interpreted by the 
> console as a clickable link:
> 
> print("http://www.example.com")
> 
> 
> 
> 
> -- 
> Steve
> "Cheer up," they said, "things could be worse." So I cheered 
> up, and sure enough, things got worse.

I can appreciate all that and pretty much knew most of it already. At
this point I'm not so much concerned with how to put characters on a
white space that are clickable, we've pretty much established at least a
couple dozen messages ago that there's nothing for python to get hold of
there because of the vast number of places people might want to put
clickable links. (I actually read every message on a thread that
interests me enough to participate.)

I think the entry point to this problem is to find out how to connect to
the internet when you click that link. Then I think the nuts and bolts
of what symbols to put where for a particular target would fall into
place.




From python at deborahswanson.net  Wed Jan  4 06:43:02 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 4 Jan 2017 03:43:02 -0800
Subject: Clickable hyperlinks
In-Reply-To: <586cd0d5$0$1595$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <001401d2667f$b569b850$27b23dae@sambora>

Steve D'Aprano wrote, on January 04, 2017 2:39 AM
> 
> On Wed, 4 Jan 2017 08:32 pm, Deborah Swanson wrote:
> 
> > Thanks, Steven. Yes, of course if you want to print strings 
> you must 
> > enclose them in quotes. I think you learn that in Week 1 of any 
> > introductory course on Python.
> > 
> > But we aren't trying to print strings here, the point is to produce 
> > clickable links. I didn't enclose them with quotes because I didn't 
> > see any point in printing plain text when I wanted 
> clickable links. I 
> > actually didn't understand why you thought I should print 
> them, but it 
> > never would have occurred to me that you wanted me to print out a 
> > bunch of silly plain text strings, apparently just for the 
> heck of it.
> 
> What we have here is a failure to communicate :-)
> 
> I apologise for ruffling your feathers, but its difficult to 
> judge another person's level of knowledge. In someways you're 
> obviously quite knowledgeable about Python, but in other ways 
> you're still learning (as we all are!) and I'm afraid I may 
> have misjudged exactly what your level of knowledge was. 
> Sorry about that.
> 
> I'm not suggesting that you print "silly plain text strings" 
> just for the heck of it. You've asked how to get a clickable 
> link using Python. There is only one way I know of to get a 
> clickable link using Python:
> 
> Write out a link as plain text to another application which 
> then interprets the plain text as a clickable link.
> 
> You *might* be able to get clickable links in Python by 
> writing an entire GUI application, using (say) the tkinter 
> library, or one of the third-party GUI libraries like 
> wxPython, kivy, pyqt, or others, but I haven't a clue how. 
> But even there, your links will start off as text, which 
> means you will still need to surround them with quotes to 
> make them strings.
> 
> 
> Aside: you've actually raised a fascinating question. I 
> wonder whether there are any programming languages that 
> understand URLs as native data types, so that *source code* 
> starting with http:// etc is understood in the same way that 
> source code starting with [ is seen as a list or { as a dict?
> 
> 
> But back to your problem: short of writing you own GUI 
> application, in which case you can do *anything you like*, you can:
> 
> - write out a HTML file containing the URLs you want, in <a 
> href= ... </a> tags, then open the HTML file in a web browser 
> and let the web browser interpret the HTML tags as clickable links;
> 
> 
> - write out an Excel spreadsheet, using whatever format Excel 
> expects, open the spreadsheet in Excel, and let Excel 
> interpret the mystery format as a clickable link;
> 
> - print the URL to the console, and see if the console is 
> smart enough to interpret it as a clickable link.
> 
> 
> I'm sorry that I can't give you a one-sentence answer "just 
> use such-and-such a function, that does exactly what you want 
> in a platform-independent manner" :-(
> 
> 
> 
> 
> -- 
> Steve
> "Cheer up," they said, "things could be worse." So I cheered 
> up, and sure enough, things got worse.

Well, well. People mix and people misunderstand and misjudge each other.
It's the way of things with people. I just needed to tell you how it all
looked from my side.  So are we done with that?  I certainly hope so.

I'm quite well aware by now that there is no one-sentence answer to my
original question, if there's any coherent answer at all. Them's the
breaks. Live with it or live without it, it doesn't care.

I do appreciate the education I've gotten on this thread about the
issues involved. But I rather imagine that near term anyway, I'll only
be pondering it now and then, and maybe poking around a bit. Who knows,
maybe I'll eventually invent the solution and make my first million
dollars from it.  haha, yeah right.

So it goes.


Deborah




From redstone-cold at 163.com  Wed Jan  4 07:15:06 2017
From: redstone-cold at 163.com (iMath)
Date: Wed, 4 Jan 2017 04:15:06 -0800 (PST)
Subject: Introducing my Python/PyQt5 powered Bing wallpaper open source project
Message-ID: <ed92bd00-b89b-4781-95eb-82a43a32f2ef@googlegroups.com>

Hello everyone ,
I'd like to introduce my Python/PyQt5 powered Bing wallpaper open source project.   
?

BingNiceWallpapers
https://github.com/redstoneleo/BingNiceWallpapers

BingNiceWallpapers can get background images from http://www.bing.com/?mkt=zh-CN and set them as your desktop wallpaper by just a single click on system tray icon.

For Windows binary installer and more information, please refer to http://mathjoy.lofter.com/post/42208d_7cabcf7 (written in simplified Chinese)

Features

Changing wallpaper in a single click on system tray icon or after a specified time interval
Windows and Linux Gnome desktop support
Delete or save the current wallpaper


Welcome to help with the project !



From rosuav at gmail.com  Wed Jan  4 07:15:46 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 4 Jan 2017 23:15:46 +1100
Subject: Clickable hyperlinks
In-Reply-To: <001401d2667f$b569b850$27b23dae@sambora>
References: <586cd0d5$0$1595$c3e8da3$5496439d@news.astraweb.com>
 <001401d2667f$b569b850$27b23dae@sambora>
Message-ID: <CAPTjJmq9JKGqSuCT4ttoWOPh6stuc4=zs_tfU7Un1s437MntMg@mail.gmail.com>

On Wed, Jan 4, 2017 at 10:43 PM, Deborah Swanson
<python at deborahswanson.net> wrote:
> I'm quite well aware by now that there is no one-sentence answer to my
> original question, if there's any coherent answer at all. Them's the
> breaks. Live with it or live without it, it doesn't care.

Yeah, there's no simple answer; however, you'll find that Python on
many platforms is entirely capable of popping a URL up in the user's
default browser. Check this out:

>>> import antigravity

This uses the 'webbrowser' module, which knows about a number of
different ways to open a browser, and will attempt them all. So if you
can figure out the UI part of things, actually making the link pop up
in a browser isn't too hard; for instance, if you're doing OAuth at
the command line and need the user to go and authenticate, you can
simply webbrowser.open("http://......./") and it'll DTRT.

ChrisA


From darcy at vex.net  Wed Jan  4 08:03:09 2017
From: darcy at vex.net (D'Arcy Cain)
Date: Wed, 4 Jan 2017 08:03:09 -0500
Subject: Clickable hyperlinks
In-Reply-To: <000601d2666d$6e7eae30$27b23dae@sambora>
References: <000601d2666d$6e7eae30$27b23dae@sambora>
Message-ID: <e741c925-fe2e-d46e-bd67-49fc43516543@vex.net>

Deborah - please trim your quoted text.

On 2017-01-04 04:32 AM, Deborah Swanson wrote:
> Thanks, Steven. Yes, of course if you want to print strings you must
> enclose them in quotes. I think you learn that in Week 1 of any
> introductory course on Python.

Closer to minute one.  When I investigated Python years ago the first 
thing I learned was;

  print "Hello, world"

> But we aren't trying to print strings here, the point is to produce
> clickable links. I didn't enclose them with quotes because I didn't see
> any point in printing plain text when I wanted clickable links. I

I'm not sure what your links are composed of but mine all look like 
sequences of characters or "strings."  It sounds like you are trying to 
make URL a first class type like strings. integers, floats, etc.  I 
can't think of any language that treats URLs as first class objects. 
Even HTML needs quotes:

   <A HREF="http://...">Go here</A>

> actually didn't understand why you thought I should print them, but it

You want to output them to something.  That often involves printing them 
to a particular handler.

> never would have occurred to me that you wanted me to print out a bunch
> of silly plain text strings, apparently just for the heck of it.

Is that really what you got from his message?

> At this point, if I pursue this any farther, it will be to look into how
> Firefox takes webpage titles and urls out of its sqlite database and
> makes objects you can click on to open the webpages. That's the basic
> technology I'd need to find a way to talk (write) python into doing.

I can assure you that FF prints the string at some point.  It may wrap 
it in HTML tags first but printing is what it does.  Also, the URLs are 
stored as strings.  SQLite has no URL type.  If it did then it would 
still store it as a string somewhere.  PostGreSQL would let you create a 
URL type if you wanted but you would still need to wrap it in quotes 
(single in this case) when you created the entry.

> If it's even worth it. On a practical level it's not worth it, way too
> much work for the teensy advantage of having it to use. It might be some
> giggles to figure out how to do it and maybe I will sometime just for
> funsies.

In all the messages in this thread I still don't understand what this 
"teensy advantage" is supposed to be.  Do you want to be able to do this:

   make_web_link(http://...)

instead of:

   make_web_link("http://...")

-- 
D'Arcy J.M. Cain
System Administrator, Vex.Net
http://www.Vex.Net/ IM:darcy at Vex.Net
VoIP: sip:darcy at Vex.Net


From rbistolfi at gmail.com  Wed Jan  4 08:44:34 2017
From: rbistolfi at gmail.com (Rodrigo Bistolfi)
Date: Wed, 4 Jan 2017 10:44:34 -0300
Subject: Clickable hyperlinks
In-Reply-To: <586cd0d5$0$1595$c3e8da3$5496439d@news.astraweb.com>
References: <586c8ab3$0$1506$c3e8da3$5496439d@news.astraweb.com>
 <000601d2666d$6e7eae30$27b23dae@sambora>
 <mailman.220.1483522295.2395.python-list@python.org>
 <586cd0d5$0$1595$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAMQZ-RdmmpJi2db0+UJoz4bTimKfsFGk7eNMME6PS31Gq=-g8Q@mail.gmail.com>

2017-01-04 7:39 GMT-03:00 Steve D'Aprano <steve+python at pearwood.info>:

> On Wed, 4 Jan 2017 08:32 pm, Deborah Swanson wrote:
>
> Aside: you've actually raised a fascinating question. I wonder whether
> there
> are any programming languages that understand URLs as native data types, so
> that *source code* starting with http:// etc is understood in the same way
> that source code starting with [ is seen as a list or { as a dict?
> ...
>

Some Smalltalk implementations have something that comes close:

st> 'https://python.org' asUrl retrieveContents

`asUrl` would be a string method returning a URL instance, which also has a
convenient method `retrieveContents` wrapping an http client. Not hard to
do with Python, I think this could be an interesting exercise for a learner.


From rhodri at kynesim.co.uk  Wed Jan  4 08:47:14 2017
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Wed, 4 Jan 2017 13:47:14 +0000
Subject: Screwing Up looping in Generator
In-Reply-To: <009e01d2662f$b1bf0e30$27b23dae@sambora>
References: <009e01d2662f$b1bf0e30$27b23dae@sambora>
Message-ID: <c28a96f7-3bcc-9444-0e43-14d727f535e6@kynesim.co.uk>

On 04/01/17 02:10, Deborah Swanson wrote:
> Sayth Renshaw wrote, on January 03, 2017 5:36 PM
>>
>> So can I call the generator twice and receive the same file
>> twice in 2 for loops?
>>
>> Once to get the files name and the second to process?
>>
>>  for file in rootobs:
>>         base = os.path.basename(file.name)
>>         write_to = os.path.join("output",
>> os.path.splitext(base)[0] + ".csv")
>>         with open(write_to, 'w', newline='') as csvf:
>>             for file in rootobs:
>>               # create and write csv
>>
>> Cheers
>>
>> Sayth
>
> I don't see why not, if you let the first one run to completion and then
> do it again a second time. Assuming your generator doesn't somehow
> delete or modify the file specifications as it yields them. It would be
> helpful to see the code for rootobs, if you have it.

Ahem.  If Sayth is using the correct terminology and rootobs actually is 
a generator (not, say, a list or tuple), then no it won't work.  Once a 
generator is exhausted, it's exhausted.  Besides, the nested for-loops 
over the same iterable is a dead giveaway that something is wrong.


-- 
Rhodri James *-* Kynesim Ltd


From darcy at vex.net  Wed Jan  4 08:58:02 2017
From: darcy at vex.net (D'Arcy Cain)
Date: Wed, 4 Jan 2017 08:58:02 -0500
Subject: Clickable hyperlinks
In-Reply-To: <CAMQZ-RdmmpJi2db0+UJoz4bTimKfsFGk7eNMME6PS31Gq=-g8Q@mail.gmail.com>
References: <586c8ab3$0$1506$c3e8da3$5496439d@news.astraweb.com>
 <000601d2666d$6e7eae30$27b23dae@sambora>
 <mailman.220.1483522295.2395.python-list@python.org>
 <586cd0d5$0$1595$c3e8da3$5496439d@news.astraweb.com>
 <CAMQZ-RdmmpJi2db0+UJoz4bTimKfsFGk7eNMME6PS31Gq=-g8Q@mail.gmail.com>
Message-ID: <78f5dfcb-0b76-96c3-03ce-32d69f5561bd@vex.net>

On 2017-01-04 08:44 AM, Rodrigo Bistolfi wrote:
> 2017-01-04 7:39 GMT-03:00 Steve D'Aprano <steve+python at pearwood.info>:
>> Aside: you've actually raised a fascinating question. I wonder whether
>> there
>> are any programming languages that understand URLs as native data types, so
>> that *source code* starting with http:// etc is understood in the same way
>> that source code starting with [ is seen as a list or { as a dict?
>
> Some Smalltalk implementations have something that comes close:
>
> st> 'https://python.org' asUrl retrieveContents

But notice that even here the URL has to be defined as a string.  To be 
a first class object you would need to do something like this:

   url = https://python.org/

The only time you would see that is in config files and languages like 
shell where everything is a string so no quotes necessary.  They are 
implied.

> `asUrl` would be a string method returning a URL instance, which also has a
> convenient method `retrieveContents` wrapping an http client. Not hard to
> do with Python, I think this could be an interesting exercise for a learner.

Sure but the issue is, what to do with it.  In any case, it's still just 
a wrapper around various string methods.  You still need to give the 
class a string to create the object.

-- 
D'Arcy J.M. Cain
System Administrator, Vex.Net
http://www.Vex.Net/ IM:darcy at Vex.Net
VoIP: sip:darcy at Vex.Net


From wrw at mac.com  Wed Jan  4 09:41:25 2017
From: wrw at mac.com (William Ray Wing)
Date: Wed, 04 Jan 2017 09:41:25 -0500
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I do
 not know what to choose.
In-Reply-To: <04dc51b5-d546-427f-8ad2-d69284682bdf@googlegroups.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
 <64837604-9f3a-806c-d631-fcc352738952@schwertberger.de>
 <mailman.183.1483488743.2395.python-list@python.org>
 <04dc51b5-d546-427f-8ad2-d69284682bdf@googlegroups.com>
Message-ID: <DE50D7AC-C3ED-445E-BBC2-BF87576E3EA8@mac.com>


> On Jan 4, 2017, at 1:54 AM, Antonio Caminero Garcia <tonycamgar at gmail.com> wrote:
> 
> On Tuesday, January 3, 2017 at 4:12:34 PM UTC-8, Dietmar Schwertberger wrote:
>> On 02.01.2017 12:38, Antonio Caminero Garcia wrote:
>> You did not try Wing IDE? It looks less like a spacecraft. Maybe you 
>> like it.
>> Maybe the difference is that Wing is from Python people while the ones 
>> you listed are from Java people.
> 
> That sounds interesting. By the look of it I think I am going to give it a try.
> 
> 

[byte]


> I want editor with those IDE capabilities and git integration, with optionally  cool stuff as for example remote debugging. 

I use Wing, and I think you will like it.  It *is* pythonic, and for what it is worth, offers remote debugging as one of its more recently added features.

-Bill




From random832 at fastmail.com  Wed Jan  4 09:43:04 2017
From: random832 at fastmail.com (Random832)
Date: Wed, 04 Jan 2017 09:43:04 -0500
Subject: Simulating int arithmetic with wrap-around
In-Reply-To: <58667385$0$1609$c3e8da3$5496439d@news.astraweb.com>
References: <58667385$0$1609$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <1483540984.1580961.837095401.1ADA7773@webmail.messagingengine.com>

On Fri, Dec 30, 2016, at 09:47, Steve D'Aprano wrote:
> Again, assume both operands are in range for an N-bit signed integer.
> What's
> a good way to efficiently, or at least not too inefficiently, do the
> calculations in Python?

I'd do something like:

bit_mask = (1 << bits) - 1 # 0xFFFF
sign_bit = 1 << (bits - 1) # 0x8000
sign_ext = ~bit_mask # ...FFFFF0000

def signed(value): 
    if value & sign_bit:
        return value | sign_ext
    else:
        return value & bit_mask

def unsigned(value):
    return value & bit_mask

And also avoid doing it on intermediate steps where it can be shown to
not affect the result or allow the value to grow too large.


From grant.b.edwards at gmail.com  Wed Jan  4 10:35:17 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Wed, 4 Jan 2017 15:35:17 +0000 (UTC)
Subject: Clickable hyperlinks
References: <o4hb66$4sf$1@blaine.gmane.org>
 <007b01d26619$97de4eb0$27b23dae@sambora>
Message-ID: <o4j4nl$qba$1@blaine.gmane.org>

On 2017-01-03, Deborah Swanson <python at deborahswanson.net> wrote:
> Grant Edwards wrote, on January 03, 2017 3:13 PM
>> 
>> On 2017-01-03, Deborah Swanson <python at deborahswanson.net> wrote:
>> 
>> > I'm sorry, I should have said a GUI console because I 
>> wouldn't expect 
>> > a text-based console to produce clickable links.
>> 
>> What's a "GUI console"?

> The GUI consoles I have are in Pycharm, the IDLE that comes with
> Anaconda, and Spyder. PyCharm and IDLE both ask for internet access when
> I open them, so they're capable of opening links, but whether that means
> their output space is capable of handling clickable links I don't know.

Thanks, that's a bit clearer.  For those of us from the Unix world
"console" means something else.

> I do know printing a full url with the %s specifier or entering a url
> and clicking enter just gives you the plain text url. Obviously, not all
> GUI consoles are enabled recognize and make clickable links from
> correctly formatted urls.
>
> I was hoping there was some functionality in python to make clickable
> links. Could be a package, if the core language doesn't have it.

There is no definition for what a "clickable link" is unless you're
sending HTML to a web browser.  That means there's no way to create
funcationality to make one.

-- 
Grant Edwards               grant.b.edwards        Yow! I'm not an Iranian!!
                                  at               I voted for Dianne
                              gmail.com            Feinstein!!



From grant.b.edwards at gmail.com  Wed Jan  4 10:42:29 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Wed, 4 Jan 2017 15:42:29 +0000 (UTC)
Subject: Clickable hyperlinks
References: <007b01d26619$97de4eb0$27b23dae@sambora>
 <cf1ab04a-5e85-038c-9712-78b0abaef4b5@gmail.com>
Message-ID: <o4j555$qba$2@blaine.gmane.org>

On 2017-01-04, Michael Torrie <torriem at gmail.com> wrote:

> On my Linux machine, the terminal emulators I've used all make a regular
> url printed out into a clickable link (or at least a right-clickable
> link).  This is just something they try to do with all things that look
> like urls.  Sometimes it's helpful, often it's annoying.

What I have done is defined a window manager root menu entry that
opens a web browser on the current text selection.  That lets me
"click" on a link in any application that suport the standard X11
text-selection mechanism (which is almost all of them).

>> I was hoping there was some functionality in python to make clickable
>> links. Could be a package, if the core language doesn't have it.
>
> No, there is not.  If you made a full GUI app using a toolkit like
> GTK or Qt, you can indeed place hyperlinks on your forms and the
> operating system will automatically connect them to the web browser.
> But not in text-mode terminal apps.

For me it's double-click to select the url in the terminal window or
PDF viewer or whaterver, then right-click on the root window and pick
the menu entry that says 'Firefox [sel]' or 'Chrome [sel]'.  It's a
few extra steps, but it works for almostly any application that
displays text.

-- 
Grant Edwards               grant.b.edwards        Yow! Where do your SOCKS
                                  at               go when you lose them in
                              gmail.com            th' WASHER?



From tim at akwebsoft.com  Wed Jan  4 11:15:44 2017
From: tim at akwebsoft.com (Tim Johnson)
Date: Wed, 4 Jan 2017 07:15:44 -0900
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <87wpeb45eq.fsf@rudin.co.uk>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
 <ba923722-087d-4c13-aaf6-0950a370c27b@googlegroups.com>
 <20170103191311.GB18910@mail.akwebsoft.com>
 <mailman.149.1483470792.2395.python-list@python.org>
 <87wpeb45eq.fsf@rudin.co.uk>
Message-ID: <20170104161544.GA6597@mail.akwebsoft.com>

* Paul Rudin <paul.nospam at rudin.co.uk> [170103 23:17]:
> Tim Johnson <tim at akwebsoft.com> writes:
> 
> > * Antonio Caminero Garcia <tonycamgar at gmail.com> [170102 20:56]:
> >> Guys really thank you for your answers. Basically now I am more
> >> emphasizing in learning in depth a tool and get stick to it so I
> >> can get a fast workflow. Eventually I will learn Vim and its
> >> python developing setup, I know people who have been programming
> >> using Vim for almost 20 years and they did not need to change
> >> editor (that is really awesome). 
> >
> >  Bye the way, one thing I like about the GUI based vim is that it
> >  supports tabs, where emacs does not.
> 
> M-x package-install tabbar
  :) Thank you. list-packages is my friend ...
-- 
Tim 
http://www.akwebsoft.com, http://www.tj49.com


From rgaddi at highlandtechnology.invalid  Wed Jan  4 12:50:26 2017
From: rgaddi at highlandtechnology.invalid (Rob Gaddi)
Date: Wed, 4 Jan 2017 09:50:26 -0800
Subject: Simulating int arithmetic with wrap-around
In-Reply-To: <ed3hbbFi2mdU1@mid.individual.net>
References: <58667385$0$1609$c3e8da3$5496439d@news.astraweb.com>
 <8737gz4tlp.fsf@nightsong.com> <ed3hbbFi2mdU1@mid.individual.net>
Message-ID: <o4jci8$obk$1@dont-email.me>

On 01/03/2017 10:00 PM, Gregory Ewing wrote:
> Paul Rubin wrote:
>> My first thought is towards the struct module, especially if you want to
>> handle a bunch of such integers at the same time.  Or maybe the array
>> module or some combination.
>
> Or possibly numpy.
>

Agreed.  If you had to do a lot of calculations on arbitrary sized 
signed/unsigned ints, figuring how to parallelize them into numpy arrays 
would save you a ton of time.

-- 
Rob Gaddi, Highland Technology -- www.highlandtechnology.com
Email address domain is currently out of order.  See above to fix.


From flebber.crue at gmail.com  Wed Jan  4 14:09:41 2017
From: flebber.crue at gmail.com (Sayth Renshaw)
Date: Wed, 4 Jan 2017 11:09:41 -0800 (PST)
Subject: Screwing Up looping in Generator
In-Reply-To: <mailman.229.1483538351.2395.python-list@python.org>
References: <009e01d2662f$b1bf0e30$27b23dae@sambora>
 <c28a96f7-3bcc-9444-0e43-14d727f535e6@kynesim.co.uk>
 <mailman.229.1483538351.2395.python-list@python.org>
Message-ID: <b9c1341f-40aa-48d1-8fb0-2bcb8f3918cc@googlegroups.com>

For completeness I was close this is the working code.

def get_list_of_names(generator_arg):
    name_set = set()
    for name in generator_arg:
        base = os.path.basename(name.name)
        filename = os.path.splitext(base)[0]
        name_set.add(filename)
    return name_set


def data_attr(roots):
    """Get the root object and iter items."""
    for name in names:
        directory = "output"
        write_name = name + ".csv"
        with open(os.path.join(directory, write_name), 'w', newline='') as csvf:
            race_writer = csv.writer(csvf, delimiter=','
)


thanks for your time and assistance. It's much appreciated

Sayth


From maillist at schwertberger.de  Wed Jan  4 15:44:45 2017
From: maillist at schwertberger.de (Dietmar Schwertberger)
Date: Wed, 4 Jan 2017 21:44:45 +0100
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <DE50D7AC-C3ED-445E-BBC2-BF87576E3EA8@mac.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
 <64837604-9f3a-806c-d631-fcc352738952@schwertberger.de>
 <mailman.183.1483488743.2395.python-list@python.org>
 <04dc51b5-d546-427f-8ad2-d69284682bdf@googlegroups.com>
 <DE50D7AC-C3ED-445E-BBC2-BF87576E3EA8@mac.com>
Message-ID: <9ca1868f-7d81-9163-a403-008a85f69c7b@schwertberger.de>

On 04.01.2017 15:41, William Ray Wing wrote:
> I use Wing, and I think you will like it.  It *is* pythonic, and for what it is worth, offers remote debugging as one of its more recently added features.
Obviously, you had no other choice than using Wing ;-)

The remote debugging has been around for some years. I have been using 
it quite often to debug on my Raspberry Pi, Nokia N900 and Jolla Phone, 
all running some Linux system. It works well. It is or was a bit 
complicated to set up. I think this has been improved with Wing 6, but I 
did not need it in the last weeks, so I don't know.

Regards,

Dietmar


From maillist at schwertberger.de  Wed Jan  4 16:09:30 2017
From: maillist at schwertberger.de (Dietmar Schwertberger)
Date: Wed, 4 Jan 2017 22:09:30 +0100
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <04dc51b5-d546-427f-8ad2-d69284682bdf@googlegroups.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
 <64837604-9f3a-806c-d631-fcc352738952@schwertberger.de>
 <mailman.183.1483488743.2395.python-list@python.org>
 <04dc51b5-d546-427f-8ad2-d69284682bdf@googlegroups.com>
Message-ID: <ededc552-c53f-860a-8ba1-97a58ddeb25d@schwertberger.de>

On 04.01.2017 07:54, Antonio Caminero Garcia wrote:
> Unfortunately most of the time I am still using print and input functions. I know that sucks, I did not use the pdb module, I guess that IDE debuggers leverage such module.
pdb is actually quite useful. On my Windows PCs I can invoke python on 
any .py file with the -i command line switch by right clicking in the 
Explorer and selecting "Debug". Now when the script crashes, I can 
inspect variables without launching a full-scale IDE or starting the 
script from the command line. For such quick fixes I have also a context 
menu entry "Edit" for editing with Pythonwin, which is still quite OK as 
editor and has no licensing restrictions or installation requirements. 
This is a nice option when you deploy your installation to many PCs over 
the network.

For the print functions vs. debugger:
The most useful application for a debugger like Wing is not for 
bug-fixing, but to set a break point and then interactively develop on 
the debugger console and with the IDE editor's autocompletion using 
introspection on the live objects. This is very helpful for hardware 
interfacing, network protocols or GUI programs. It really boosted my 
productivity in a way I could not believe before. This is something most 
people forget when they evaluate programming languages. It's not the 
language or syntax that counts, but the overall environment. Probably 
the only other really interactive language and environment is Forth.

> If it happens to be Arduino I normally use a sublime plugin called Stino
> https://github.com/Robot-Will/Stino
> (1337 people starred that cool number :D)
Well, it is CodeWarrior which was quite famous at the time of the 68k Macs.
The company was bought by Motorola and the IDE is still around for 
Freescale/NXP/Qualcomm microcontrollers like the HCS08 8 bit series. 
Around ten years ago the original CodeWarrior IDE was migrated to 
something Eclipse based.
When I last evaluated HCS08 vs. Arduino, the HCS08 won due to the better 
debug interface and native USB support. HCS08 is still quite cool, but 
when it comes to documentation, learning curve, tools etc. the Arduinos 
win....


Regards,

Dietmar



From wrw at mac.com  Wed Jan  4 17:01:31 2017
From: wrw at mac.com (William Ray Wing)
Date: Wed, 04 Jan 2017 17:01:31 -0500
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I do
 not know what to choose.
In-Reply-To: <9ca1868f-7d81-9163-a403-008a85f69c7b@schwertberger.de>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
 <64837604-9f3a-806c-d631-fcc352738952@schwertberger.de>
 <mailman.183.1483488743.2395.python-list@python.org>
 <04dc51b5-d546-427f-8ad2-d69284682bdf@googlegroups.com>
 <DE50D7AC-C3ED-445E-BBC2-BF87576E3EA8@mac.com>
 <9ca1868f-7d81-9163-a403-008a85f69c7b@schwertberger.de>
Message-ID: <1BDA202B-83E2-4C6F-9FD4-64E28561BD6D@mac.com>


> On Jan 4, 2017, at 3:44 PM, Dietmar Schwertberger <maillist at schwertberger.de> wrote:
> 
> On 04.01.2017 15:41, William Ray Wing wrote:
>> I use Wing, and I think you will like it.  It *is* pythonic, and for what it is worth, offers remote debugging as one of its more recently added features.
> Obviously, you had no other choice than using Wing ;-)

I should have said something.  First, and to the best of my knowledge, I have no relationship with the Wing developers other than being a satisfied customer. Second, seven years ago, when I was reading IDE reviews and testing the more highly rated products, Wing just bubbled up to the top of the sieve I was using (features, ease of use, and the way it fit my idea of ?natural?, pretty much everyone's standard list).

> 
> The remote debugging has been around for some years. I have been using it quite often to debug on my Raspberry Pi, Nokia N900 and Jolla Phone, all running some Linux system. It works well. It is or was a bit complicated to set up. I think this has been improved with Wing 6, but I did not need it in the last weeks, so I don't know.

They claim it has been, but like you, I haven?t had need to test it on the new release.

Thanks,
Bill

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



From zxpatric at gmail.com  Wed Jan  4 17:14:10 2017
From: zxpatric at gmail.com (zxpatric at gmail.com)
Date: Wed, 4 Jan 2017 14:14:10 -0800 (PST)
Subject: Work between multiple processes
Message-ID: <892336f7-0adb-431b-aed0-b871d14ac16c@googlegroups.com>

Hi everyone,

I ran into a case that I need to create a work process of an application (Jython so has to call using java.exe) which will collect the data based on what main process indicates. 

(1) I tried multiprocessing package, no luck. Java.exe can't be called from Process class?

(2) I tried subprocess. subprocess.communicate function will wait for the work process to terminate so to return.

 
either (1) or (2) doesn't work out well. Please suggest.  Global system queue?

Thanks,
Patrick.


From hpj at urpla.net  Wed Jan  4 17:15:03 2017
From: hpj at urpla.net (Hans-Peter Jansen)
Date: Wed, 04 Jan 2017 23:15:03 +0100
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
Message-ID: <10677094.xGjz0IE2Dp@xrated>

On Montag, 2. Januar 2017 03:38:53 Antonio Caminero Garcia wrote:
> Hello, I am having a hard time deciding what IDE or IDE-like code editor
> should I use. This can be overwhelming.
> 
> So far, I have used Vim, Sublime, Atom, Eclipse with PyDev, Pycharm,
> IntelliJ with Python plugin.

Well, since nobody mentioned it, yet: eric is doing quite nice here.
With on the fly error checking, jedi and qscintilla calltips and 
autocompletion, git integration (using a plugin), graphical debugger, it's 
grown to a capable IDE over the years.

Given, it's a fully open source, PyQt based project, it also shows the powers 
of Python3 and PyQt.

Pete


From rosuav at gmail.com  Wed Jan  4 17:49:14 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 05 Jan 2017 10:49:14 +1200
Subject: Clickable hyperlinks
Message-ID: <3004643574@f38.n261.z1.binkp.net>

On Thu, Jan 5, 2017 at 9:58 AM, Deborah Swanson
<python at deborahswanson.net> wrote:
> Chris Angelico wrote, on January 04, 2017 4:16 AM
>> This uses the 'webbrowser' module, which knows about a number
>> of different ways to open a browser, and will attempt them
>> all. So if you can figure out the UI part of things, actually
>> making the link pop up in a browser isn't too hard; for
>> instance, if you're doing OAuth at the command line and need
>> the user to go and authenticate, you can simply
>> webbrowser.open("http://......./") and it'll DTRT.
>>
>
> Thank you, thank you! Finally, at least one person on this list knows
> about something (anything) in the python world that is internet aware.
> It's also occurred to me that Beautifulsoup downloads data from a url,
> so that code must have access to some kind of an internet engine too.

We've been all talking at cross purposes a bit in this thread. Most of us 
thought you were talking about the *user interface* of a clickable link, but if 
you're talking about the *mechanics* of HTTP downloads, Python has excellent 
facilities. I'd recommend checking out the third-party 'requests' module on 
PyPI.

> I googled antigravity and found a number of interesting links.
>
> The History of Python: import antigravity
> http://python-history.blogspot.com/2010/06/import-antigravity.html
>
> Among other things, it was added to Python 3 in 2010, so it's been
> around a little while. And a comment mentions that "The antigravity
> module is also included in Python 2.7."
>
> And a reddit poster tells us that "if you type 'import antigravity' into
> a Python command line your default browser opens the XKCD comic 'Python'
> in a tab."
> https://www.reddit.com/r/ProgrammerHumor/comments/1hvb5n/til_if_you_type
> _import_antigravity_into_a_python/
>
> An "import antigravity" video at
> https://www.youtube.com/watch?v=_V0V6Rk6Fp4

Hehe, yeah. It's a big joke that started because XKCD mentioned the language. 
But actually, the source code for antigravity.py itself isn't significant; all 
it does is call on the webbrowser module:

https://docs.python.org/3/library/webbrowser.html

> Yes, I'd gotten as far as figuring out that you don't need a clickable
> link. Code that opens a url in a browse would do the job just fine. Or
> the webbrowser.open("http://......./") in a Linux terminal you suggest.
> (I just have to get my Linux machine up and running again to try it.)
>
> All in all, given that clickable urls in a console is a non-starter,
> this hits the nail on the head. Many thanks again!

Cool! Glad I could help out a bit. There are a few different things you can 
consider:

1) Open up a browser tab and let the user see the result 2) Make the request 
programmatically and access the text of the page for further processing
3) Invoke a hidden web browser, browse to a URL, submit form data, etc, as a 
means of testing a web server.

All three are possible. Take your pick!

ChrisA



From python at deborahswanson.net  Wed Jan  4 17:58:42 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 4 Jan 2017 14:58:42 -0800
Subject: Clickable hyperlinks
In-Reply-To: <CAPTjJmq9JKGqSuCT4ttoWOPh6stuc4=zs_tfU7Un1s437MntMg@mail.gmail.com>
Message-ID: <002401d266de$18bc4450$27b23dae@sambora>

Chris Angelico wrote, on January 04, 2017 4:16 AM
> 
> On Wed, Jan 4, 2017 at 10:43 PM, Deborah Swanson 
> <python at deborahswanson.net> wrote:
> > I'm quite well aware by now that there is no one-sentence 
> answer to my 
> > original question, if there's any coherent answer at all. 
> Them's the 
> > breaks. Live with it or live without it, it doesn't care.
> 
> Yeah, there's no simple answer; however, you'll find that 
> Python on many platforms is entirely capable of popping a URL 
> up in the user's default browser. Check this out:
> 
> >>> import antigravity
> 
> This uses the 'webbrowser' module, which knows about a number 
> of different ways to open a browser, and will attempt them 
> all. So if you can figure out the UI part of things, actually 
> making the link pop up in a browser isn't too hard; for 
> instance, if you're doing OAuth at the command line and need 
> the user to go and authenticate, you can simply 
> webbrowser.open("http://......./") and it'll DTRT.
> 

Thank you, thank you! Finally, at least one person on this list knows
about something (anything) in the python world that is internet aware.
It's also occurred to me that Beautifulsoup downloads data from a url,
so that code must have access to some kind of an internet engine too.

I googled antigravity and found a number of interesting links. 

The History of Python: import antigravity
http://python-history.blogspot.com/2010/06/import-antigravity.html

Among other things, it was added to Python 3 in 2010, so it's been
around a little while. And a comment mentions that "The antigravity
module is also included in Python 2.7."

And a reddit poster tells us that "if you type 'import antigravity' into
a Python command line your default browser opens the XKCD comic 'Python'
in a tab."
https://www.reddit.com/r/ProgrammerHumor/comments/1hvb5n/til_if_you_type
_import_antigravity_into_a_python/

An "import antigravity" video at
https://www.youtube.com/watch?v=_V0V6Rk6Fp4

And its page in the Package Index:
https://pypi.python.org/pypi/antigravity/0.1, with a Page Not Found
Error for the Home Page. So it doesn't look like there's any alternative
but to download it and look at the code.

Yes, I'd gotten as far as figuring out that you don't need a clickable
link. Code that opens a url in a browse would do the job just fine. Or
the webbrowser.open("http://......./") in a Linux terminal you suggest.
(I just have to get my Linux machine up and running again to try it.)

All in all, given that clickable urls in a console is a non-starter,
this hits the nail on the head. Many thanks again!

Deborah


   



From tjreedy at udel.edu  Wed Jan  4 18:21:55 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Wed, 4 Jan 2017 18:21:55 -0500
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <g1qo6c1svbttrfnber6sfko92mqjqlmafa@4ax.com>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <CAPTjJmrwnjd+em2beKAYyZAe6k6EJg4xO2Brzg=BOUzG+SFE3Q@mail.gmail.com>
 <cc7ace5b-46ca-0727-2be6-a173f89e9df1@lucidity.plus.com>
 <CAPTjJmo=1+bQe-2OMOwikJj11ziQVm0fZKBeHEeTMbo718YBFw@mail.gmail.com>
 <mailman.184.1483489020.2395.python-list@python.org>
 <40adacf3-b4de-4243-8cb5-6ea5fb74cf18@googlegroups.com>
 <g1qo6c1svbttrfnber6sfko92mqjqlmafa@4ax.com>
Message-ID: <o4k02g$9p6$1@blaine.gmane.org>

On 1/3/2017 10:15 PM, Dennis Lee Bieber wrote:

> And that statement tells us you are trying to run from within some
> IDE/editor which is trapping Python exceptions and producing a dialog
> box for them.

IDLE does this when one runs code from the editor, because it 
cannot/should not inject error messages into the editor buffer...
AND it replaces the ^ with red highlighting of the code pointed to.  No 
information is lost.  Apparently, some beginners do not see the 
connection between the SyntaxError box and the red highlighting.  I 
think I should add something to the box.  Maybe 'The error was detected 
at the point of the red highlighting.'

> Instead, save your script (if you haven't yet) as a file
> (whatever.py).
>
> Open a command line interpreter/shell.
>
> Navigate (cd ...) to where you saved the file
>
> Type "python whatever.py"

What a nuisance.

> Copy and paste the results of the CLI/Shell window.

Or one can hit F5 to run the code or Alt-X to just check the syntax.
A beginner should do this every few lines, and it should be as easy as 
possible to check.  If one needs to ask about a syntax error, one can 
copy the code up and including the highlighted part. Example:

"When I run this code in IDLE

def is_same(target, number:
         if

I get a SyntaxError at 'if'."

If the OP had known to do this, the error might have been seen without 
posting.

-- 
Terry Jan Reedy



From rosuav at gmail.com  Wed Jan  4 18:49:15 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 5 Jan 2017 10:49:15 +1100
Subject: Clickable hyperlinks
In-Reply-To: <002401d266de$18bc4450$27b23dae@sambora>
References: <CAPTjJmq9JKGqSuCT4ttoWOPh6stuc4=zs_tfU7Un1s437MntMg@mail.gmail.com>
 <002401d266de$18bc4450$27b23dae@sambora>
Message-ID: <CAPTjJmqe0F_yDK9R4iO9N2CE0Vo2fz1b+X=6-ftuTaS5iNTEDA@mail.gmail.com>

On Thu, Jan 5, 2017 at 9:58 AM, Deborah Swanson
<python at deborahswanson.net> wrote:
> Chris Angelico wrote, on January 04, 2017 4:16 AM
>> This uses the 'webbrowser' module, which knows about a number
>> of different ways to open a browser, and will attempt them
>> all. So if you can figure out the UI part of things, actually
>> making the link pop up in a browser isn't too hard; for
>> instance, if you're doing OAuth at the command line and need
>> the user to go and authenticate, you can simply
>> webbrowser.open("http://......./") and it'll DTRT.
>>
>
> Thank you, thank you! Finally, at least one person on this list knows
> about something (anything) in the python world that is internet aware.
> It's also occurred to me that Beautifulsoup downloads data from a url,
> so that code must have access to some kind of an internet engine too.

We've been all talking at cross purposes a bit in this thread. Most of
us thought you were talking about the *user interface* of a clickable
link, but if you're talking about the *mechanics* of HTTP downloads,
Python has excellent facilities. I'd recommend checking out the
third-party 'requests' module on PyPI.

> I googled antigravity and found a number of interesting links.
>
> The History of Python: import antigravity
> http://python-history.blogspot.com/2010/06/import-antigravity.html
>
> Among other things, it was added to Python 3 in 2010, so it's been
> around a little while. And a comment mentions that "The antigravity
> module is also included in Python 2.7."
>
> And a reddit poster tells us that "if you type 'import antigravity' into
> a Python command line your default browser opens the XKCD comic 'Python'
> in a tab."
> https://www.reddit.com/r/ProgrammerHumor/comments/1hvb5n/til_if_you_type
> _import_antigravity_into_a_python/
>
> An "import antigravity" video at
> https://www.youtube.com/watch?v=_V0V6Rk6Fp4

Hehe, yeah. It's a big joke that started because XKCD mentioned the
language. But actually, the source code for antigravity.py itself
isn't significant; all it does is call on the webbrowser module:

https://docs.python.org/3/library/webbrowser.html

> Yes, I'd gotten as far as figuring out that you don't need a clickable
> link. Code that opens a url in a browse would do the job just fine. Or
> the webbrowser.open("http://......./") in a Linux terminal you suggest.
> (I just have to get my Linux machine up and running again to try it.)
>
> All in all, given that clickable urls in a console is a non-starter,
> this hits the nail on the head. Many thanks again!

Cool! Glad I could help out a bit. There are a few different things
you can consider:

1) Open up a browser tab and let the user see the result
2) Make the request programmatically and access the text of the page
for further processing
3) Invoke a hidden web browser, browse to a URL, submit form data,
etc, as a means of testing a web server.

All three are possible. Take your pick!

ChrisA


From tjreedy at udel.edu  Wed Jan  4 18:57:53 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Wed, 4 Jan 2017 18:57:53 -0500
Subject: Clickable hyperlinks
In-Reply-To: <000601d2666d$6e7eae30$27b23dae@sambora>
References: <586c8ab3$0$1506$c3e8da3$5496439d@news.astraweb.com>
 <000601d2666d$6e7eae30$27b23dae@sambora>
Message-ID: <o4k25v$j3h$1@blaine.gmane.org>

On 1/4/2017 4:32 AM, Deborah Swanson wrote:

> My original question was whether python had anything to provide this
> functionality, and the answer appears to be a resounding NO!!!

I would say 'Yes, but with user effort'.

To have a string interpreted as a clickable link, you send the string to 
software capable of creating a clickable link, plus the information 
'this is a clickable link'*.  There are two ways to tag a string as a 
link.  One is to use markup around the url in the string itself. 
'<url>' and html are example.  Python provides multiple to make this 
easy. The other is to tag the string with a separate argument.  Python 
provides tkinter, which wraps tk Text widgets, which have a powerful tag 
system.  One can define a Link tag that will a) cause text to be 
displayed, for instance, blue and underlined and b) cause clicks on the 
text to generate a web request.  One could then use
   mytext.insert('insert', 'http://www.example.com', Link)
Browser must do something similar when they encounter when they 
encounter html link tags.

* If the software directly recognizes a bare url such as 
'http://www.example.com' as a link, without further indication, then it 
should have a way to disable conversion to a clickable link.

-- 
Terry Jan Reedy



From ceh329 at gmail.com  Wed Jan  4 19:02:52 2017
From: ceh329 at gmail.com (Charles Heizer)
Date: Wed, 4 Jan 2017 16:02:52 -0800 (PST)
Subject: MySQL schema sync or diff
Message-ID: <68944b94-64d5-41a2-8d85-9a6471f5caab@googlegroups.com>

Hello,
I have a MySQL database that is not managed (yet) and I would like to get an output or diff against my new model file. I'm using flask-sqlalchemy. 

Are there any modules that would help me discover the differences so that I can script a migration to begin using flask-migrate?

Thanks!


From python at deborahswanson.net  Wed Jan  4 19:07:08 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 4 Jan 2017 16:07:08 -0800
Subject: Clickable hyperlinks
In-Reply-To: <e741c925-fe2e-d46e-bd67-49fc43516543@vex.net>
Message-ID: <002901d266e7$a8583fc0$27b23dae@sambora>

D'Arcy Cain wrote, on Wednesday, January 04, 2017 5:03 AM
> 
> Deborah - please trim your quoted text.

Yes, I will. Some lists want to have it all to review in one message,
some want it trimmed to just the lines you are responding to. I was just
waiting to see what this list wants.
 
> On 2017-01-04 04:32 AM, Deborah Swanson wrote:
<snip>
 
> > But we aren't trying to print strings here, the point is to produce 
> > clickable links. I didn't enclose them with quotes because I didn't 
> > see any point in printing plain text when I wanted 
> clickable links. I
> 
> I'm not sure what your links are composed of but mine all look like 
> sequences of characters or "strings."  It sounds like you are 
> trying to 
> make URL a first class type like strings. integers, floats, etc.  I 
> can't think of any language that treats URLs as first class objects. 
> Even HTML needs quotes:
> 
>    <A HREF="http://...">Go here</A>
 
It seemed reasonable that you might be able to print urls, which is why
I tried the experiment with all of Steven's suggested formats. But I was
highly skeptical that any would work without some kind of modifiers to a
bare print statement.

> > actually didn't understand why you thought I should print 
> them, but it
> 
> You want to output them to something.  That often involves 
> printing them 
> to a particular handler.

Yes, that's one of the things I would expect if we could print them.

> > never would have occurred to me that you wanted me to print out a 
> > bunch of silly plain text strings, apparently just for the 
> heck of it.
> 
> Is that really what you got from his message?

Please forgive me, and I hope Steven forgives me too, but I was sick to
death of all the beating on a dead horse (using Python to make clickable
links in a console, any console). I'd taken heart when he first
suggested his print experiment, because it was a plausible approach. But
I lost my temper when he upbraided me in this message for failing to
enclose my strings in quotes, in a most patronizing kind of way, when
printing out plain text was absolutely nowhere on the progress toward a
solution scale. I've been quite impressed with Steven's knowledge and
talent, and after fending off the throng of unseeing naysayers all
afternoon, it was just a little too much. I really should have closed my
email reader hours before I read and replied to this message. Shoulda,
coulda, woulda.
 
<snip>

> I can assure you that FF prints the string at some point.  It 
> may wrap 
> it in HTML tags first but printing is what it does.  Also, 
> the URLs are 
> stored as strings.  SQLite has no URL type.  If it did then it would 
> still store it as a string somewhere.  PostGreSQL would let 
> you create a 
> URL type if you wanted but you would still need to wrap it in quotes 
> (single in this case) when you created the entry.

I have no doubt that some variant of printing is involved. Transporting
urls to the internet is an output process. FF's sqlite implementation
does store urls as a text field in at least 2 tables. I would be
interested in how FF takes those text urls and opens web pages with
them, although I've learned and figured out just today some ways that
Python can also do it. Turns out clickable links were a red herring.

If Steven's original suggestion included anything but a bare print
statement, like the use of a special specifier or linking the print
statement to some module, the use of quoted strings would have at least
been worthy of consideration. But we all know what
print("http://www.wherever.com") would print, and it would be utterly
worthless for the purpose at hand. Trying the print statement without
the quotes was a least a possibility, if there was any awareness in the
print code of urls and what to do with them. That was the whole point of
this fishing expedition, as I saw it. To see if there was any
undocumented or narrowly known-of features in the print code.

<snip>
> In all the messages in this thread I still don't understand what this 
> "teensy advantage" is supposed to be.  Do you want to be able 
> to do this:
> 
>    make_web_link(http://...)
> 
> instead of:
> 
>    make_web_link("http://...")
> 
> -- 
> D'Arcy J.M. Cain
> System Administrator, Vex.Net
> http://www.Vex.Net/ IM:darcy at Vex.Net
> VoIP: sip:darcy at Vex.Net

You probably didn't see my oneliner on the "why do it" part in the swarm
of messages on this thread yesterday. In it I mentioned that the use
would be to open urls in the data I'm working with while I'm debugging
the code that uses them. I want to see what pages they open, without
having to leave my IDE. (Obviously I'd have to open another .py file,
but that would be easier and quicker than the alternatives.) I never
intended my original question to be any more than a frivolous toss out
into the sea, to see if anyone knew an answer. I was flat out astonished
when it blew up into the mini-monster that it did. 

Is make_web_link("http://...") valid python code? That's exactly the
kind of answer I was looking for, and I will try it (or look it up if it
needs something imported) as soon as I send this off. Thank you.

It's possible you caught just the tail end of a hot mess without seeing
all the irrational vitriol and nonsense that led up to this message.
Lucky you.

Deborah



From torriem at gmail.com  Wed Jan  4 19:47:39 2017
From: torriem at gmail.com (Michael Torrie)
Date: Wed, 4 Jan 2017 17:47:39 -0700
Subject: Clickable hyperlinks
In-Reply-To: <002401d266de$18bc4450$27b23dae@sambora>
References: <002401d266de$18bc4450$27b23dae@sambora>
Message-ID: <7417e761-dce6-bf09-acf9-074cbda24d81@gmail.com>

On 01/04/2017 03:58 PM, Deborah Swanson wrote:
> Thank you, thank you! Finally, at least one person on this list knows
> about something (anything) in the python world that is internet aware.
> It's also occurred to me that Beautifulsoup downloads data from a url,
> so that code must have access to some kind of an internet engine too.

Except that you never mentioned anything about this in your posts
before. It seemed to me you were asking about printing out clickable
hyperlinks with python.  Calling the OS to launch a browser to view a
url is a different beast which is why no one mentioned it before.

If you don't tell us what you're actually trying to do (your end goal),
things are more frustrating for everyone.  If you had said early on you
just want to be able to send the user to a particular url in a web
browser, what Chris suggested would have been said a long time ago,
rather than focusing on console output which is what you were asking
about and focusing attention on.

Just so you know, BeautifulSoup does not do any internet access itself;
it's only an HTML parser. You have to fetch web pages using something
like python's urllib and then feed the data to BeautifulSoup.  urllib is
not a web browser though.  It can pretend to be a browser as far as the
server is concerned but it knows nothing about javascript or rendering.
It just retrieves bytes which you can then feed to BeautifulSoup or some
other parser.

> Yes, I'd gotten as far as figuring out that you don't need a clickable
> link. Code that opens a url in a browse would do the job just fine. 

Good! I just wish you would have mentioned this much earlier as your end
goal.

> Or the webbrowser.open("http://......./") in a Linux terminal you suggest.
> (I just have to get my Linux machine up and running again to try it.)

The webbrowser module does not require console or terminal output. It
will work on Windows or Linux if I'm not mistaken.  It asks the OS to
launch the default browser and load the indicated url.

> All in all, given that clickable urls in a console is a non-starter,
> this hits the nail on the head. Many thanks again!




From steve+comp.lang.python at pearwood.info  Wed Jan  4 20:51:40 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 05 Jan 2017 13:51:40 +1200
Subject: Hey, I'm new to python so don't judge.
References: <2025125030@f38.n261.z1.binkp.net>
Message-ID: <1029557784@f38.n261.z1.binkp.net>

On Thursday 05 January 2017 10:21, Terry Reedy wrote:

> On 1/3/2017 10:15 PM, Dennis Lee Bieber wrote:
>
>> And that statement tells us you are trying to run from within some
>> IDE/editor which is trapping Python exceptions and producing a dialog
>> box for them.
>
> IDLE does this when one runs code from the editor, because it
> cannot/should not inject error messages into the editor buffer...
> AND it replaces the ^ with red highlighting of the code pointed to.  No
> information is lost.  Apparently, some beginners do not see the
> connection between the SyntaxError box and the red highlighting.

Some people may not even be able to distinguish red from other colours. Those 
with red-green colourblindness will probably see the red as a sort of muddy 
brown that hardly stands out as different from usual black text.

http://wearecolorblind.com/

One should never use colour alone as the only indicator of status.

http://stackoverflow.com/questions/1498669/gui-design-for-color-blindness

http://davemeeker.com/color-blind-considerations-for-ui-design/


> I
> think I should add something to the box.  Maybe 'The error was detected
> at the point of the red highlighting.'


I just tested the REPL in idle for 2.7.4, and I get this:

>>> print Hello World
SyntaxError: invalid syntax


where "print" is green text on a white background, and "World" is black text on 
a red background. That may be unfriendly to the colourblind, and makes coping 
and pasting the error less helpful. I suggest:

- check the colours in a colourblindness simulator, and pay attention to the
contrast; is the text still clear?

- include the ^ caret as the primary status indicator, delegating colour to
secondary; this makes errors in IDLE a little more like the same experience in 
the standard REPL.


If I open a Python file containing:

print Hello World

and choose "Check Module", IDLE highlights the word "World" in red and displays 
a dialog showing:

There's an error in your program:
invalid syntax

Suggestion:

Change the dialog box to display a read-only text field showing the traceback:

  File "idletest.py", line 1
    print Hello World
                    ^
SyntaxError: invalid syntax


and add a button "Copy traceback" to allow the user to copy the text of the 
traceback and paste it into an email.

(Strictly speaking, the Copy button is redundant if the user can select the 
text in the field, but beginners may not realise the text can be selected.)



>> Instead, save your script (if you haven't yet) as a file
>> (whatever.py).
>>
>> Open a command line interpreter/shell.
>>
>> Navigate (cd ...) to where you saved the file
>>
>> Type "python whatever.py"
>
> What a nuisance.

*shrug* If you're a Linux user, chances are you already have a shell open and
ready to go. And with tab completion, you don't have to type as much as you 
might think. It just becomes second nature after a while.

I type something like "py<TAB>path<TAB>what<TAB><ENTER>" and the shell will 
autocomplete directory and filenames.

Anyway, this isn't an argument over which is better, IDLE or the system 
terminal. They both have their advantages and disadvantages, and in practice 
the real answer to "which is better?" is always "whichever one you are used 
to".



--
Steven
"Ever since I learned about confirmation bias, I've been seeing it everywhere." 
- Jon Ronson



From python at deborahswanson.net  Wed Jan  4 21:29:00 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Thu, 05 Jan 2017 14:29:00 +1200
Subject: Clickable hyperlinks
Message-ID: <3272602342@f38.n261.z1.binkp.net>

Terry Reedy wrote, on January 04, 2017 10:18 PM
>
> On 1/5/2017 12:11 AM, Deborah Swanson wrote:
> > Terry Reedy wrote, on January 04, 2017 3:58 PM
>
> >> To have a string interpreted as a clickable link, you send the
string to
> >> software capable of creating a clickable link, plus the information

> >> 'this is a clickable link'*.  There are two ways to tag a string as
a
> >> link.  One is to use markup around the url in the string itself.
> >> '<url>' and html are example.  Python provides multiple to make
this
> >> easy. The other is to tag the string with a separate argument.
> >> Python provides tkinter, which wraps tk Text widgets, which have a
> >> powerful tag system.  One can define a Link tag that will a) cause
text
> >> to be displayed, for instance, blue and underlined and b) cause
clicks on
> >> the text to generate a web request.  One could then use
> >> mytext.insert('insert', 'http://www.example.com', Link) Browser
> >> must do something similar when they encounter when they encounter
> >> html link tags.
> >
> > I've actually moved on from my original question to one of opening a

> > url in a browser with python, which seems to be a much more easily
> > achieved goal.
>
> > But someone else mentioned tkinter, and I looked at it awhile ago
but
> > haven't used it for anything. That really could be the way to go if
> > you want to make clickable links, although you still need some kind
of
> > internet engine to open the url in a browser.
>
> IDLE allows a user to add help menu entries that, when clicked on,
open
> either a local file or an internet url.  For instance, adding the pair

> 'Pillow' and "https://pillow.readthedocs.io/en/latest/" in > the
Settings
> dialog adda "Pillow" to the help menu (after the standard stuff).
> Clicking on Help => Pillow opens
> "https://pillow.readthedocs.io/en/latest/" in the default browswer.
> IDLE just used the webbrowser module to do this.  No use re-inventing
> the wheel.  If instead "Pillow" were a link in text, the click handler

> should do something similar.

Yes, unless someone suggests something better, the webbrowser module looks like 
the way to go for opening urls in a browser.
>
> > You say, "There are two ways to tag a string as a link. One is to
use
> > markup around the url in the string itself. '<url>' and html are
> > examples.  Python provides multiple ways to make this easy."
> >
> > Can you tell me where I'd begin to look for these? Are they in the
> > core language, or in packages?
>
> I was referring to using either % or .format string formatting.  Both
> are in the core and described somewhere in the Library manual.  '%'
> should be in the Symbols page of the Index and 'format' on
> the 'F' page.
>
> --
> Terry Jan Reedy

I looked up % in the Symbols page, but I didn't see any specifier related to 
urls. It would be nice if there was something like a %u for url format, but it 
isn't in there.

I also tried

        print(<url>"http//python.org"</url>)
                ^
but got 'SyntaxError: invalid syntax', with the red arrow pointing at the first 
angle bracket. I also tried

        print(<html>"http//python.org"</html>)
            ^
and got the same syntax error, but I'm not sure if that's how you meant html 
should be used.

I also tried to look up 'format', but there's no such entry in the Index. There 
are a lot of entries that begin with 'format', but none of them mention urls or 
anything link related. 'format_field() (string.Formatter method)' looked like a 
possibility, but again, I didn't see anything to format a link with. Maybe I 
didn't look hard enough, or didn't see something that _would_ work.

As I've said, at this point I've moved on to directly opening a url in a 
browser with the webbrowser module. All I originally wanted to do was be able 
to open a url without leaving my IDE while I was debugging data that has urls 
in it. Clickable links are really just eye candy that I don't need if I can get 
the same result programmatically. But I was curious whether there are any ways 
to tag a string as a link in a print statement. If there are, I didn't find 
any, but thanks for your suggestions!

Deborah



From steve+comp.lang.python at pearwood.info  Wed Jan  4 21:51:41 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 05 Jan 2017 13:51:41 +1100
Subject: Hey, I'm new to python so don't judge.
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <CAPTjJmrwnjd+em2beKAYyZAe6k6EJg4xO2Brzg=BOUzG+SFE3Q@mail.gmail.com>
 <cc7ace5b-46ca-0727-2be6-a173f89e9df1@lucidity.plus.com>
 <CAPTjJmo=1+bQe-2OMOwikJj11ziQVm0fZKBeHEeTMbo718YBFw@mail.gmail.com>
 <mailman.184.1483489020.2395.python-list@python.org>
 <40adacf3-b4de-4243-8cb5-6ea5fb74cf18@googlegroups.com>
 <g1qo6c1svbttrfnber6sfko92mqjqlmafa@4ax.com> <o4k02g$9p6$1@blaine.gmane.org>
 <mailman.240.1483572151.2395.python-list@python.org>
Message-ID: <586db4c9$0$2921$c3e8da3$76491128@news.astraweb.com>

On Thursday 05 January 2017 10:21, Terry Reedy wrote:

> On 1/3/2017 10:15 PM, Dennis Lee Bieber wrote:
> 
>> And that statement tells us you are trying to run from within some
>> IDE/editor which is trapping Python exceptions and producing a dialog
>> box for them.
> 
> IDLE does this when one runs code from the editor, because it
> cannot/should not inject error messages into the editor buffer...
> AND it replaces the ^ with red highlighting of the code pointed to.  No
> information is lost.  Apparently, some beginners do not see the
> connection between the SyntaxError box and the red highlighting.

Some people may not even be able to distinguish red from other colours. Those 
with red-green colourblindness will probably see the red as a sort of muddy 
brown that hardly stands out as different from usual black text.

http://wearecolorblind.com/

One should never use colour alone as the only indicator of status.

http://stackoverflow.com/questions/1498669/gui-design-for-color-blindness

http://davemeeker.com/color-blind-considerations-for-ui-design/


> I
> think I should add something to the box.  Maybe 'The error was detected
> at the point of the red highlighting.'


I just tested the REPL in idle for 2.7.4, and I get this:

>>> print Hello World
SyntaxError: invalid syntax


where "print" is green text on a white background, and "World" is black text on 
a red background. That may be unfriendly to the colourblind, and makes coping 
and pasting the error less helpful. I suggest:

- check the colours in a colourblindness simulator, and pay attention to the 
contrast; is the text still clear?

- include the ^ caret as the primary status indicator, delegating colour to 
secondary; this makes errors in IDLE a little more like the same experience in 
the standard REPL.


If I open a Python file containing:

print Hello World

and choose "Check Module", IDLE highlights the word "World" in red and displays 
a dialog showing:

There's an error in your program:
invalid syntax

Suggestion:

Change the dialog box to display a read-only text field showing the traceback:

  File "idletest.py", line 1
    print Hello World
                    ^
SyntaxError: invalid syntax


and add a button "Copy traceback" to allow the user to copy the text of the 
traceback and paste it into an email.

(Strictly speaking, the Copy button is redundant if the user can select the 
text in the field, but beginners may not realise the text can be selected.)



>> Instead, save your script (if you haven't yet) as a file
>> (whatever.py).
>>
>> Open a command line interpreter/shell.
>>
>> Navigate (cd ...) to where you saved the file
>>
>> Type "python whatever.py"
> 
> What a nuisance.

*shrug* If you're a Linux user, chances are you already have a shell open and 
ready to go. And with tab completion, you don't have to type as much as you 
might think. It just becomes second nature after a while.

I type something like "py<TAB>path<TAB>what<TAB><ENTER>" and the shell will 
autocomplete directory and filenames.

Anyway, this isn't an argument over which is better, IDLE or the system 
terminal. They both have their advantages and disadvantages, and in practice 
the real answer to "which is better?" is always "whichever one you are used 
to".



-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From python at deborahswanson.net  Wed Jan  4 21:53:02 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Thu, 05 Jan 2017 14:53:02 +1200
Subject: Clickable hyperlinks
Message-ID: <4018729974@f38.n261.z1.binkp.net>

Rhodri James wrote, on January 05, 2017 3:53 AM
>
> On 05/01/17 04:52, Deborah Swanson wrote:
> > My original question was in fact whether there was a way to make
> > clickable hyperlinks in a console. I was persuaded after about 10
> > replies that the answer was no,
>
> Then you were persuaded wrong; the actual answer was "this isn't a
> meaningful question since it's based on incorrect assumptions."
> Translating that to "No" is just as much a mistake as
> translating it to
> "Yes."
>
> --
> Rhodri James *-* Kynesim Ltd

Actually, your statement "this isn't a meaningful question since it's based on 
incorrect assumptions" is false. PyCharm outputs clickable links to the 
console, but they aren't web links, they simply link to lines of code. I'd seen 
that PyCharm can make links in the console that aren't web enabled, so it 
seemed, and in fact it is, reasonable to assume that it could be done for urls. 
I just wanted to know if anyone knew how to do it.

Granted, the suggestion to use tkinter to enable the links came up much later 
than in the first 10 or so replies, and since tkinter makes clickable links 
possible, that's another reason my question wasn't based on false assumptions. 
It simply appears that the early responders to my question went off on a 
tangent of what is or is not technologically possible, and all of the 
approaches under consideration were in fact dead ends.

But clickable links turns out to be just eye candy, and the real result I 
wanted, which is opening urls in a browser from my IDE, is much more quickly 
and easily done programmatically. Although I didn't see this before I asked my 
question, and only saw it after reading quite a few replies.

Perhaps though, I should have said "I was persuaded after about 10 replies that 
that no one understood what I was asking." But that just seemed plain rude, so 
I went with "the answer was no".



From darcy at vex.net  Wed Jan  4 22:00:09 2017
From: darcy at vex.net (D'Arcy Cain)
Date: Wed, 4 Jan 2017 22:00:09 -0500
Subject: Clickable hyperlinks
In-Reply-To: <002401d266de$18bc4450$27b23dae@sambora>
References: <002401d266de$18bc4450$27b23dae@sambora>
Message-ID: <cf280d5e-beee-0e0f-1ef4-79a05c99bf2a@vex.net>

On 2017-01-04 05:58 PM, Deborah Swanson wrote:
>> the user to go and authenticate, you can simply
>> webbrowser.open("http://......./") and it'll DTRT.
>
> Thank you, thank you! Finally, at least one person on this list knows
> about something (anything) in the python world that is internet aware.

Lots of things in Python are Internet aware.  That's not the question 
you asked though.

> It's also occurred to me that Beautifulsoup downloads data from a url,
> so that code must have access to some kind of an internet engine too.

Nope.  You have to feed it HTML.  You either need to generate that or 
capture it from somewhere.

-- 
D'Arcy J.M. Cain
System Administrator, Vex.Net
http://www.Vex.Net/ IM:darcy at Vex.Net
VoIP: sip:darcy at Vex.Net


From rosuav at gmail.com  Wed Jan  4 22:08:04 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 05 Jan 2017 15:08:04 +1200
Subject: Clickable hyperlinks
Message-ID: <1835463384@f38.n261.z1.binkp.net>

On Thu, Jan 5, 2017 at 2:24 PM, D'Arcy Cain <darcy at vex.net> wrote:
> Think of it this way.  You drop a ring down a drain.  You can ask two
> questions, "How do I remove a drain trap?" or "How do I recover a ring that
> I dropped down the drain?"  If you ask the first question you will get lots
> of advice on tools and buckets, etc.  People will assume that the drain is
> blocked.  Ask the second question and someone might mention a magnet and a
> piece of string.

... and then you follow up with "it's a gold ring, magnet won't touch it", and 
we'll go off on a tangent about whether the ring is sufficiently plain that it 
might be the One Ring, and shouldn't you destroy it instead of retrieving 
it.... because that's what we do here
:D

ChrisA



From rustompmody at gmail.com  Wed Jan  4 22:22:29 2017
From: rustompmody at gmail.com (Rustom Mody)
Date: Wed, 4 Jan 2017 19:22:29 -0800 (PST)
Subject: Clickable hyperlinks
In-Reply-To: <mailman.243.1483574836.2395.python-list@python.org>
References: <e741c925-fe2e-d46e-bd67-49fc43516543@vex.net>
 <002901d266e7$a8583fc0$27b23dae@sambora>
 <mailman.243.1483574836.2395.python-list@python.org>
Message-ID: <40b7d676-6e5c-4855-89ba-f19c8bbf479e@googlegroups.com>

This thread does lead to the question:
Is the Url type in python less first-class than it could be?

In scheme I could point to something like this
https://docs.racket-lang.org/net/url.html

Is there something equivalent in python?


From darcy at vex.net  Wed Jan  4 22:24:35 2017
From: darcy at vex.net (D'Arcy Cain)
Date: Wed, 4 Jan 2017 22:24:35 -0500
Subject: Clickable hyperlinks
In-Reply-To: <002901d266e7$a8583fc0$27b23dae@sambora>
References: <002901d266e7$a8583fc0$27b23dae@sambora>
Message-ID: <08aab9ab-eff2-86de-8b68-8b8514aedf0a@vex.net>

On 2017-01-04 07:07 PM, Deborah Swanson wrote:
> D'Arcy Cain wrote, on Wednesday, January 04, 2017 5:03 AM
>> In all the messages in this thread I still don't understand what this
>> "teensy advantage" is supposed to be.  Do you want to be able
>> to do this:
>>
>>    make_web_link(http://...)
>>
>> instead of:
>>
>>    make_web_link("http://...")

[...]

> Is make_web_link("http://...") valid python code? That's exactly the

It's just a made up name.  My point was that the first was syntactically 
incorrect and the second, while not a real method, was at least parseable.

I think I saw someone else mention this but it bears repeating.  When 
you ask a question make sure you are presenting the problem and not your 
solution to a secret problem.  Always tell us the actual problem you are 
trying to solve.  You will get much better answers.

Think of it this way.  You drop a ring down a drain.  You can ask two 
questions, "How do I remove a drain trap?" or "How do I recover a ring 
that I dropped down the drain?"  If you ask the first question you will 
get lots of advice on tools and buckets, etc.  People will assume that 
the drain is blocked.  Ask the second question and someone might mention 
a magnet and a piece of string.

-- 
D'Arcy J.M. Cain
System Administrator, Vex.Net
http://www.Vex.Net/ IM:darcy at Vex.Net
VoIP: sip:darcy at Vex.Net


From rosuav at gmail.com  Wed Jan  4 22:27:18 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 05 Jan 2017 15:27:18 +1200
Subject: Clickable hyperlinks
Message-ID: <2710021487@f38.n261.z1.binkp.net>

On Thu, Jan 5, 2017 at 3:19 PM, Deborah Swanson
<python at deborahswanson.net> wrote:
> I downloaded the code from the Package Index, but there really wasn't
> much in it. This is the entire .py file:

Ehh, wrong file. Try the one in the standard library:

https://github.com/python/cpython/blob/master/Lib/antigravity.py
https://github.com/python/cpython/blob/master/Lib/webbrowser.py

Or you can look in your installed Python - "import webbrowser; 
print(webbrowser.__file__)" will tell you where.

ChrisA



From flebber.crue at gmail.com  Wed Jan  4 22:32:22 2017
From: flebber.crue at gmail.com (Sayth Renshaw)
Date: Wed, 4 Jan 2017 19:32:22 -0800 (PST)
Subject: Is there a good process or library for validating changes to XML
 format?
Message-ID: <1604a9b9-08ee-40fb-9014-abc2d5d989f1@googlegroups.com>

Afternoon

Is there a good library or way I could use to check that the author of the XML doc I am using doesn't make small changes to structure over releases?

Not fully over this with XML but thought that XSD may be what I need, if I search "python XSD" I get a main result for PyXB and generateDS (https://pythonhosted.org/generateDS/). 

Both seem to be libraries for generating bindings to structures for parsing so maybe I am searching the wrong thing. What is the right thing to search?

Cheers

Sayth


From rosuav at gmail.com  Wed Jan  4 23:08:04 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 5 Jan 2017 15:08:04 +1100
Subject: Clickable hyperlinks
In-Reply-To: <08aab9ab-eff2-86de-8b68-8b8514aedf0a@vex.net>
References: <002901d266e7$a8583fc0$27b23dae@sambora>
 <08aab9ab-eff2-86de-8b68-8b8514aedf0a@vex.net>
Message-ID: <CAPTjJmrQdOvnzHMQnexwCfib958sv_kkSCkAG+DeAn=m==wYGA@mail.gmail.com>

On Thu, Jan 5, 2017 at 2:24 PM, D'Arcy Cain <darcy at vex.net> wrote:
> Think of it this way.  You drop a ring down a drain.  You can ask two
> questions, "How do I remove a drain trap?" or "How do I recover a ring that
> I dropped down the drain?"  If you ask the first question you will get lots
> of advice on tools and buckets, etc.  People will assume that the drain is
> blocked.  Ask the second question and someone might mention a magnet and a
> piece of string.

... and then you follow up with "it's a gold ring, magnet won't touch
it", and we'll go off on a tangent about whether the ring is
sufficiently plain that it might be the One Ring, and shouldn't you
destroy it instead of retrieving it.... because that's what we do here
:D

ChrisA


From python at deborahswanson.net  Wed Jan  4 23:19:33 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 4 Jan 2017 20:19:33 -0800
Subject: Clickable hyperlinks
In-Reply-To: <CAPTjJmq9JKGqSuCT4ttoWOPh6stuc4=zs_tfU7Un1s437MntMg@mail.gmail.com>
Message-ID: <005701d2670a$eb5d9b80$27b23dae@sambora>

Chris Angelico wrote, on January 04, 2017 4:16 AM
> 
> Yeah, there's no simple answer; however, you'll find that 
> Python on many platforms is entirely capable of popping a URL 
> up in the user's default browser. Check this out:
> 
> >>> import antigravity

I downloaded the code from the Package Index, but there really wasn't
much in it. This is the entire .py file:

STRIP_URL = "http://xkcd.com/353/"

def start():
    return STRIP_URL

And setup.py is equally disappointing:
from distutils.core import setup

setup(
    name='antigravity',
    version='0.1',
    description='A really simple module that allow everyone to do
"import antigravity"',
    author='Fabien Schwob',
    author_email='antigravity at x-phuture.com',
    url='http://fabien.schwob.org/antigravity/',
    packages=['antigravity'],
)

> This uses the 'webbrowser' module, which knows about a number 
> of different ways to open a browser, and will attempt them 
> all. So if you can figure out the UI part of things, actually 
> making the link pop up in a browser isn't too hard; for 
> instance, if you're doing OAuth at the command line and need 
> the user to go and authenticate, you can simply 
> webbrowser.open("http://......./") and it'll DTRT.
> 
> ChrisA

All the action of antigravity must be done by the import statement. When
import opens a module that immediately returns a url, it must have a
mechanism to open it in a browser.

It would be very easy to do the same thing with my own .py and import it
into another .py.  

Or, take a look at import's code and figure out how it opens a url in a
browser. I imagine it's the 'webbrowser' module you mention. If it tries
several methods, just pick one that will work for you.

Or, take a look at this Index of Packages Matching 'webbrowser' (~50
packages)
https://pypi.python.org/pypi?%3Aaction=search&term=webbrowser&submit=sea
rch

D'Arcy was right, there's lots in python that's internet aware, though
that wasn't the question I knew to ask.



From rosuav at gmail.com  Wed Jan  4 23:27:19 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 5 Jan 2017 15:27:19 +1100
Subject: Clickable hyperlinks
In-Reply-To: <005701d2670a$eb5d9b80$27b23dae@sambora>
References: <CAPTjJmq9JKGqSuCT4ttoWOPh6stuc4=zs_tfU7Un1s437MntMg@mail.gmail.com>
 <005701d2670a$eb5d9b80$27b23dae@sambora>
Message-ID: <CAPTjJmq=8SsyMYBJQgT7+fZ_BP4YdAzm9Q=pBpyb4CBMy1LLBg@mail.gmail.com>

On Thu, Jan 5, 2017 at 3:19 PM, Deborah Swanson
<python at deborahswanson.net> wrote:
> I downloaded the code from the Package Index, but there really wasn't
> much in it. This is the entire .py file:

Ehh, wrong file. Try the one in the standard library:

https://github.com/python/cpython/blob/master/Lib/antigravity.py
https://github.com/python/cpython/blob/master/Lib/webbrowser.py

Or you can look in your installed Python - "import webbrowser;
print(webbrowser.__file__)" will tell you where.

ChrisA


From torriem at gmail.com  Wed Jan  4 23:41:20 2017
From: torriem at gmail.com (Michael Torrie)
Date: Wed, 4 Jan 2017 21:41:20 -0700
Subject: Clickable hyperlinks
In-Reply-To: <005701d2670a$eb5d9b80$27b23dae@sambora>
References: <005701d2670a$eb5d9b80$27b23dae@sambora>
Message-ID: <2cf52e7b-147e-9f51-23a5-0847ee298865@gmail.com>

On 01/04/2017 09:19 PM, Deborah Swanson wrote:
> Or, take a look at import's code and figure out how it opens a url in a
> browser. I imagine it's the 'webbrowser' module you mention. If it tries
> several methods, just pick one that will work for you.

webbrowser is part of the python standard library:
https://docs.python.org/3/library/webbrowser.html

It uses whatever method is appropriate for the platform for opening a
url in the user's default browser.

> Or, take a look at this Index of Packages Matching 'webbrowser' (~50
> packages)
> https://pypi.python.org/pypi?%3Aaction=search&term=webbrowser&submit=sea
> rch

There may be modules in there that will be useful, but the first port of
call should always be the python standard library.

> D'Arcy was right, there's lots in python that's internet aware, though
> that wasn't the question I knew to ask.

That's why it's always good to state your end goal when asking about things.






From python at deborahswanson.net  Wed Jan  4 23:52:28 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 4 Jan 2017 20:52:28 -0800
Subject: Clickable hyperlinks
In-Reply-To: <CAPTjJmqe0F_yDK9R4iO9N2CE0Vo2fz1b+X=6-ftuTaS5iNTEDA@mail.gmail.com>
Message-ID: <005801d2670f$84ab39b0$27b23dae@sambora>

Chris Angelico wrote, on January 04, 2017 3:49 PM
> 
> On Thu, Jan 5, 2017 at 9:58 AM, Deborah Swanson 
> <python at deborahswanson.net> wrote:
> >
> > Thank you, thank you! Finally, at least one person on this list
knows 
> > about something (anything) in the python world that is internet
aware. 
<snip>
> 
> We've been all talking at cross purposes a bit in this 
> thread. Most of us thought you were talking about the *user 
> interface* of a clickable link, but if you're talking about 
> the *mechanics* of HTTP downloads, Python has excellent 
> facilities. I'd recommend checking out the third-party 
> 'requests' module on PyPI.

My original question was in fact whether there was a way to make
clickable hyperlinks in a console. I was persuaded after about 10
replies that the answer was no, and I tried with little success to
change the question to one of directly opening a url in a browser from
Python. (In hindsight, maybe I should have started a new thread.) Turns
out this version of the question does have good answers, but the revised
question got totally drowned out in the scramble to show that clickable
links in a console are a no-go. I'm not surprised that you didn't see
the shift in what I was looking for.

<snip>
> 
> Hehe, yeah. It's a big joke that started because XKCD 
> mentioned the language. But actually, the source code for 
> antigravity.py itself isn't significant; all it does is call 
> on the webbrowser module:
> 
https://docs.python.org/3/library/webbrowser.html

I saw how insignificant antigravity's code is when I downloaded it from
the Package Index, and I copied the current version into another message
of yours that I replied to before this one. The original antigravity may
have used webbrowser, but now it just returns a url and hands it off to
import to open it. Maybe the author didn't know import had that
capability until after antigravity had been in the wild awhile.
Regardless, antigravity does point the way to pythonic web access.

> Yes, I'd gotten as far as figuring out that you don't need a clickable

> link. Code that opens a url in a browser would do the job just fine.
Or 
> the webbrowser.open("http://......./") in a Linux terminal you 
> suggest. (I just have to get my Linux machine up and running again to 
> try it.)
>
> All in all, given that clickable urls in a console is a non-starter, 
> this hits the nail on the head. Many thanks again!

Cool! Glad I could help out a bit. There are a few different things you
can consider:

1) Open up a browser tab and let the user see the result
2) Make the request programmatically and access the text of the page for
further processing
3) Invoke a hidden web browser, browse to a URL, submit form data, etc,
as a means of testing a web server.

All three are possible. Take your pick!

ChrisA

I have a fourth option. I use Firefox with profiles and I could make one
specifically for this task, and have the code open the page in that
profile. This would give it it's own window, history, bookmarks, and
sqlite database, which could be handy if a particular url continues to
be a problem, or I want to track it for some reason. In this project I
usually would want to look at the photos, so a text download wouldn't be
that helpful. But it could be in some other project, and I expect to be
doing quite a bit of web work down the road.



From python at deborahswanson.net  Wed Jan  4 23:55:56 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 4 Jan 2017 20:55:56 -0800
Subject: Clickable hyperlinks
In-Reply-To: <CAPTjJmq=8SsyMYBJQgT7+fZ_BP4YdAzm9Q=pBpyb4CBMy1LLBg@mail.gmail.com>
Message-ID: <005901d26710$006c4940$27b23dae@sambora>

Chris Angelico wrote, on January 04, 2017 8:27 PM
> 
> On Thu, Jan 5, 2017 at 3:19 PM, Deborah Swanson 
> <python at deborahswanson.net> wrote:
> > I downloaded the code from the Package Index, but there really
wasn't 
> > much in it. This is the entire .py file:
> 
> Ehh, wrong file. Try the one in the standard library:
> 
https://github.com/python/cpython/blob/master/Lib/antigravity.py
https://github.com/python/cpython/blob/master/Lib/webbrowser.py

>Or you can look in your installed Python - "import webbrowser;
print>(webbrowser.__file__)" will tell you where.
>
>ChrisA

Great! I will check it out. Thanks again!



From tjreedy at udel.edu  Thu Jan  5 00:04:17 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Thu, 5 Jan 2017 00:04:17 -0500
Subject: Hey, I'm new to python so don't judge.
In-Reply-To: <586db4c9$0$2921$c3e8da3$76491128@news.astraweb.com>
References: <a54e6d99-fb2a-4be0-885e-c8075513a7eb@googlegroups.com>
 <CAPTjJmrwnjd+em2beKAYyZAe6k6EJg4xO2Brzg=BOUzG+SFE3Q@mail.gmail.com>
 <cc7ace5b-46ca-0727-2be6-a173f89e9df1@lucidity.plus.com>
 <CAPTjJmo=1+bQe-2OMOwikJj11ziQVm0fZKBeHEeTMbo718YBFw@mail.gmail.com>
 <mailman.184.1483489020.2395.python-list@python.org>
 <40adacf3-b4de-4243-8cb5-6ea5fb74cf18@googlegroups.com>
 <g1qo6c1svbttrfnber6sfko92mqjqlmafa@4ax.com> <o4k02g$9p6$1@blaine.gmane.org>
 <mailman.240.1483572151.2395.python-list@python.org>
 <586db4c9$0$2921$c3e8da3$76491128@news.astraweb.com>
Message-ID: <o4kk4e$6lp$1@blaine.gmane.org>

On 1/4/2017 9:51 PM, Steven D'Aprano wrote:
> On Thursday 05 January 2017 10:21, Terry Reedy wrote:

>> IDLE does this when one runs code from the editor, because it
>> cannot/should not inject error messages into the editor buffer...
>> AND it replaces the ^ with red highlighting of the code pointed to.  No
>> information is lost.  Apparently, some beginners do not see the
>> connection between the SyntaxError box and the red highlighting.
>
> Some people may not even be able to distinguish red from other colours. Those
> with red-green colourblindness will probably see the red as a sort of muddy
> brown that hardly stands out as different from usual black text.
>
> http://wearecolorblind.com/
>
> One should never use colour alone as the only indicator of status.
>
> http://stackoverflow.com/questions/1498669/gui-design-for-color-blindness
>
> http://davemeeker.com/color-blind-considerations-for-ui-design/

I have described what I inherited.  After I wrote this, it occurred to 
me that perhaps the error color should be flashing, a bell rung, and 
maybe even the line and column numbers included in the box.

>> I
>> think I should add something to the box.  Maybe 'The error was detected
>> at the point of the red highlighting.'
>
>
> I just tested the REPL in idle for 2.7.4, and I get this:
>
>>>> print Hello World
> SyntaxError: invalid syntax
>
>
> where "print" is green text on a white background, and "World" is black text on
> a red background. That may be unfriendly to the colourblind, and makes coping
> and pasting the error less helpful. I suggest:
>
> - check the colours in a colourblindness simulator, and pay attention to the
> contrast; is the text still clear?

User can configure most of the syntax colors.  I am not sure ir the 
error 'red' is one of them or not.

#Suggestion 1
> - include the ^ caret as the primary status indicator, delegating colour to
> secondary; this makes errors in IDLE a little more like the same experience in
> the standard REPL.

Indeed, why not both in the Shell?  IDLE must currently be deleting the 
caret line.

> If I open a Python file containing:
>
> print Hello World
>
> and choose "Check Module", IDLE highlights the word "World" in red and displays
> a dialog showing:
>
> There's an error in your program:
> invalid syntax

#Suggestion 2
> Change the dialog box to display a read-only text field showing the traceback:
>
>   File "idletest.py", line 1
>     print Hello World
>                     ^
> SyntaxError: invalid syntax

#Suggestion 3
> and add a button "Copy traceback" to allow the user to copy the text of the
> traceback and paste it into an email.
>
> (Strictly speaking, the Copy button is redundant if the user can select the
> text in the field, but beginners may not realise the text can be selected.)

Thank you for the suggestions.  I will keep a copy of this.

-- 
Terry Jan Reedy



From python at deborahswanson.net  Thu Jan  5 00:11:28 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 4 Jan 2017 21:11:28 -0800
Subject: Clickable hyperlinks
In-Reply-To: <o4k25v$j3h$1@blaine.gmane.org>
Message-ID: <005e01d26712$2c75b6f0$27b23dae@sambora>

Terry Reedy wrote, on January 04, 2017 3:58 PM
> 
> On 1/4/2017 4:32 AM, Deborah Swanson wrote:
> 
> > My original question was whether python had anything to provide this

> > functionality, and the answer appears to be a resounding NO!!!
> 
> I would say 'Yes, but with user effort'.
> 
> To have a string interpreted as a clickable link, you send the string
to 
> software capable of creating a clickable link, plus the information 
> 'this is a clickable link'*.  There are two ways to tag a string as a 
> link.  One is to use markup around the url in the string itself. 
> '<url>' and html are example.  Python provides multiple to make this 
> easy. The other is to tag the string with a separate argument.  Python

> provides tkinter, which wraps tk Text widgets, which have a powerful
tag 
> system.  One can define a Link tag that will a) cause text to be 
> displayed, for instance, blue and underlined and b) cause clicks on
the 
> text to generate a web request.  One could then use
>    mytext.insert('insert', 'http://www.example.com', Link) 
> Browser must do something similar when they encounter when they 
> encounter html link tags.

I've actually moved on from my original question to one of opening a url
in a browser with python, which seems to be a much more easily achieved
goal.

But someone else mentioned tkinter, and I looked at it while ago but
haven't used it for anything. That really could be the way to go if you
want to make clickable links, although you still need some kind of
internet engine to open the url in a browser.  PyCharm has clickable
local links in its console output, but they're not internet enabled,
they just jump to the relevant line of code.

You say, "There are two ways to tag a string as a link.  One is to use
markup around the url in the string itself. '<url>' and html are
examples.  Python provides multiple ways to make this easy." 

Can you tell me where I'd begin to look for these? Are they in the core
language, or in packages?

> * If the software directly recognizes a bare url such as 
> 'http://www.example.com' as a link, without further 
> indication, then it 
> should have a way to disable conversion to a clickable link.

One would think so.  Thanks for all your info!

> 
> -- 
> Terry Jan Reedy




From steve+comp.lang.python at pearwood.info  Thu Jan  5 00:30:42 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 05 Jan 2017 16:30:42 +1100
Subject: Clickable hyperlinks
References: <e741c925-fe2e-d46e-bd67-49fc43516543@vex.net>
 <002901d266e7$a8583fc0$27b23dae@sambora>
 <mailman.243.1483574836.2395.python-list@python.org>
 <40b7d676-6e5c-4855-89ba-f19c8bbf479e@googlegroups.com>
Message-ID: <586dda09$0$11124$c3e8da3@news.astraweb.com>

On Thursday 05 January 2017 14:22, Rustom Mody wrote:

> This thread does lead to the question:
> Is the Url type in python less first-class than it could be?
> 
> In scheme I could point to something like this
> https://docs.racket-lang.org/net/url.html

Those docs say:

"To access the text of a document from the web, first obtain its URL 
AS A STRING..." [emphasis added]

which means that URLs are not a first-class data type in Racket at all. URLs in 
Racket are just strings, exactly the same as in Python.

There is a url struct:

https://docs.racket-lang.org/net/url.html#%28def._%28%28lib._net%2Furl-
structs..rkt%29._url%29%29

but there no first-class syntactic support for them, as ints and lists have in 
Python:

123  # rather than int("123")
[1, 2]  # rather than list(1, 2)


> Is there something equivalent in python?

Just like Racket, URLs in Python are not first-class. They start as a string, 
and then you parse them into a tuple:

https://docs.python.org/3/library/urllib.parse.html

https://docs.python.org/2/library/urlparse.html


-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From torriem at gmail.com  Thu Jan  5 00:41:48 2017
From: torriem at gmail.com (Michael Torrie)
Date: Thu, 05 Jan 2017 17:41:48 +1200
Subject: Python for WEB-page !?
Message-ID: <2895939025@f38.n261.z1.binkp.net>

On 01/05/2017 04:53 PM, Victor Porton wrote:
> Ionut Predoiu wrote:
>
>> I am a beginner in programming language.
>> I want to know what version of Python I must to learn to use, beside of
>> basic language, because I want to integrate in my site 1 page in which
>> users to can made calculus based on my formulas already write behind (the
>> users will only complete some field, and after push "Calculate" button
>> will see the results in form of: table, graphic, and so on ...). Please
>> take into account that behind will be more mathematical
>> equations/formulas, so the speed I think must be take into account.
>
> Consider PyPi. I never used it, but they say, it is faster than usual
> CPython interpreter.

With respect, I don't think it's appropriate to direct a python beginner to 
PyPi.  Far better to direct him to the relevant resources (like Django) and 
focus him on the standard Python interpreter, hopefully version 3.

Besides that, there's the old expression. Premature optimization is the root of 
all evil.  Until Python is shown to be too slow for a given task, it's 
premature to think about speedups like Cython or even PyPi.



From torriem at gmail.com  Thu Jan  5 00:48:30 2017
From: torriem at gmail.com (Michael Torrie)
Date: Thu, 05 Jan 2017 17:48:30 +1200
Subject: Python for WEB-page !?
Message-ID: <2317493603@f38.n261.z1.binkp.net>

On 01/05/2017 05:57 AM, Ionut Predoiu wrote:
> Good afternoon,
>
> I am a beginner in programming language. I want to know what version
> of Python I must to learn to use, beside of basic language, because I
> want to integrate in my site 1 page in which users to can made
> calculus based on my formulas already write behind (the users will
> only complete some field, and after push "Calculate" button will see
> the results in form of: table, graphic, and so on ...). Please take
> into account that behind will be more mathematical
> equations/formulas, so the speed I think must be take into account.

While Python can do that, using a web framework to process HTTP requests and 
generate HTML to display in the browser, I don't believe Python is the 
appropriate language for the task at hand.  Most web sites that do interactive 
formula calculations like you describe do it all in the browser using 
Javascript.  No need to have a web server do all that heavy lifting at all.  A 
simple html file would contain everything you need.

Even if you want to use Python to generate the web page and process events, 
you'll still have to master Javascript at some point to make the webpages more 
interactive.



From tjreedy at udel.edu  Thu Jan  5 01:17:37 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Thu, 5 Jan 2017 01:17:37 -0500
Subject: Clickable hyperlinks
In-Reply-To: <005e01d26712$2c75b6f0$27b23dae@sambora>
References: <o4k25v$j3h$1@blaine.gmane.org>
 <005e01d26712$2c75b6f0$27b23dae@sambora>
Message-ID: <o4kodu$cvb$1@blaine.gmane.org>

On 1/5/2017 12:11 AM, Deborah Swanson wrote:
> Terry Reedy wrote, on January 04, 2017 3:58 PM

>> To have a string interpreted as a clickable link, you send the string
> to
>> software capable of creating a clickable link, plus the information
>> 'this is a clickable link'*.  There are two ways to tag a string as a
>> link.  One is to use markup around the url in the string itself.
>> '<url>' and html are example.  Python provides multiple to make this
>> easy. The other is to tag the string with a separate argument.  Python
>
>> provides tkinter, which wraps tk Text widgets, which have a powerful
> tag
>> system.  One can define a Link tag that will a) cause text to be
>> displayed, for instance, blue and underlined and b) cause clicks on
> the
>> text to generate a web request.  One could then use
>>    mytext.insert('insert', 'http://www.example.com', Link)
>> Browser must do something similar when they encounter when they
>> encounter html link tags.
>
> I've actually moved on from my original question to one of opening a url
> in a browser with python, which seems to be a much more easily achieved
> goal.

> But someone else mentioned tkinter, and I looked at it while ago but
> haven't used it for anything. That really could be the way to go if you
> want to make clickable links, although you still need some kind of
> internet engine to open the url in a browser.

IDLE allows a user to add help menu entries that, when clicked on, open 
either a local file or an internet url.  For instance, adding the pair
'Pillow' and "https://pillow.readthedocs.io/en/latest/" in the Settings 
dialog adda "Pillow" to the help menu (after the standard stuff). 
Clicking on Help => Pillow opens 
"https://pillow.readthedocs.io/en/latest/" in the default browswer. 
IDLE just used the webbrowser module to do this.  No use re-inventing 
the wheel.  If instead "Pillow" were a link in text, the click handler 
should do something similar.

> You say, "There are two ways to tag a string as a link.  One is to use
> markup around the url in the string itself. '<url>' and html are
> examples.  Python provides multiple ways to make this easy."
>
> Can you tell me where I'd begin to look for these? Are they in the core
> language, or in packages?

I was referring to using either % or .format string formatting.  Both 
are in the core and described somewhere in the Library manual.  '%' 
should be in the Symbols page of the Index and 'format' on the 'F' page.

-- 
Terry Jan Reedy



From hetchkay at gmail.com  Thu Jan  5 02:09:11 2017
From: hetchkay at gmail.com (H Krishnan)
Date: Thu, 5 Jan 2017 12:39:11 +0530
Subject: Forcing prompt to be on newline when embedding Python with stdin/out
 redirection
Message-ID: <CANWsHydFpHy+COb5aVFwePicEVPD1bz=uvU=i8pn9otDvdwOEQ@mail.gmail.com>

Hi,

I am working on embedding Python in my application. I have redirected
sys.stdin and sys.stdout to call methods from a Qt TextEdit widget.
Everything works fine except that the Python prompt does not always come in
a new line:

>>> dir()
['__builtins__', '__doc__', '__name__', '__package__']>>>

Why doesn't the prompt appear in a new line as with the default stdout?

Thanks,
Krishnan


From domini.lex at gmail.com  Thu Jan  5 02:31:08 2017
From: domini.lex at gmail.com (domini.lex at gmail.com)
Date: Wed, 4 Jan 2017 23:31:08 -0800 (PST)
Subject: how to create IPictureDisp objects with python?
In-Reply-To: <a09gpa$dhl$1@mail.cn99.com>
References: <a09gpa$dhl$1@mail.cn99.com>
Message-ID: <a6b6b7b9-de14-4fed-a6a6-f44f39214c00@googlegroups.com>

???????, 25 ??????? 2001 ?., 12:29:26 UTC+3 ???????????? Felix ???????:
> i try to host an activex control in my program . the control has a picture
> property which only accepts "IPictureDisp" interfaces. does anybody know how
> to create IPictureDisp objects? thanks.

Hi, today in 2017 i have the same problem with IPictureDisp. I saw your posts on some sources without an answer, did you find a solution?


From rus.cahimb at gmail.com  Thu Jan  5 03:23:09 2017
From: rus.cahimb at gmail.com (Ramanathan Muthaiah)
Date: Thu, 5 Jan 2017 00:23:09 -0800 (PST)
Subject: Is there a good process or library for validating changes to XML
 format?
In-Reply-To: <1604a9b9-08ee-40fb-9014-abc2d5d989f1@googlegroups.com>
References: <1604a9b9-08ee-40fb-9014-abc2d5d989f1@googlegroups.com>
Message-ID: <7c3fadf7-53a4-434c-b04b-0800c4de597a@googlegroups.com>

On Thursday, January 5, 2017 at 9:02:38 AM UTC+5:30, Sayth Renshaw wrote:
> Afternoon
> 
> Is there a good library or way I could use to check that the author of the XML doc I am using doesn't make small changes to structure over releases?
> 
> Not fully over this with XML but thought that XSD may be what I need, if I search "python XSD" I get a main result for PyXB and generateDS (https://pythonhosted.org/generateDS/). 
> 
> Both seem to be libraries for generating bindings to structures for parsing so maybe I am searching the wrong thing. What is the right thing to search?

[RM]: Have you tried 'xmllint' (though it's not Python library) ?

/Ram


From nntp.fpp at spamgourmet.com  Thu Jan  5 03:32:00 2017
From: nntp.fpp at spamgourmet.com (fpp)
Date: Thu, 05 Jan 2017 20:32:00 +1200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I do
Message-ID: <928897436@f38.n261.z1.binkp.net>

> On Thu, Jan 5, 2017 at 12:12 PM, Chris Clark <chris.p.clark at ba.com>
> wrote:
>> I want an IDE that I can use at work and home, linux and dare I say
>> windows.
>> Sublime, had to remove it from my work PC as it is not licensed.
>> Atom, loved it until it slowed down.
>> VIM, ok the best if you know vi inside out.
>> Any JAVA based IDE, just slows up on work PC's due to all the
>> background stuff that corporates insist they run.
>> Why can not someone more clever than I fork DrPython and bring it up
>> to date.
>> Its is fast, looks great and just does the job ?

I'm suprised no one in this rich thread has even mentioned SciTE : 
http://www.scintilla.org/

Admittedly it's closer to an excellent code editor than a full-blown IDE. But 
it's very lightweight and fast, cross-platform, has superb syntax coloring and 
UTF8 handling, and is highly configurable through its configuration file(s) and 
embedded LUA scripting. It's also well maintained : version 1.0 came out in 
1999, and the latest (3.7.2) is just a week old...

Its IDE side consists mostly of hotkeys to run the interpreter or compiler for 
the language you're editing, with the file in the current tab.
A side pane shows the output (prints, exceptions, errors etc.) of the running 
script.
A nice touch is that it understands these error messages and makes them 
clickable, taking you to the tab/module/line where the error occurred. Also, it 
can save its current tabs (and their state) to a "session" file for later 
reloading, which is close to the idea of a "project" in most IDEs.
Oh, and it had multi-selection and multi-editing before most of the new IDEs 
out there :-)

Personally that's about all I need for my Python activities, but it can be 
customized much further than I have done : there are "hooks" for other external 
programs than compilers/interpreters, so you can also run a linter, debugger or 
cvs from the editor.

One word of warning: unlike most newer IDEs which tend to be shiny-shiny and 
ful of bells and whistles at first sight, out of the box SciTE is
*extremely* plain looking (you could even say drab, or ugly :-).
It is up to you to decide how it should look and what it should do or not, 
through the configuration file. Fortunately the documentation is very thorough, 
and there are a lot of examples lying around to be copy/pasted (like a dark 
theme, LUA scripts etc.).

Did I mention it's lightweight ? The archive is about 1.5 MB and it just needs 
unzipping, no installation. May be worth a look if you haven't tried it yet...
fp



From flebber.crue at gmail.com  Thu Jan  5 06:00:12 2017
From: flebber.crue at gmail.com (Sayth Renshaw)
Date: Thu, 5 Jan 2017 03:00:12 -0800 (PST)
Subject: Is there a good process or library for validating changes to XML
 format?
In-Reply-To: <7c3fadf7-53a4-434c-b04b-0800c4de597a@googlegroups.com>
References: <1604a9b9-08ee-40fb-9014-abc2d5d989f1@googlegroups.com>
 <7c3fadf7-53a4-434c-b04b-0800c4de597a@googlegroups.com>
Message-ID: <b5b6e054-2042-49bc-995f-a071a9bf4638@googlegroups.com>

It definitely has more features than i knew http://xmlsoft.org/xmllint.html

Essentially thigh it appears to be aimed at checking validity and compliance of xml.
I why to check the structure of 1 xml file against the previous known structure to ensure there are no changes.

Cheers

Sayth


From cae.mefeagroup at gmail.com  Thu Jan  5 06:07:28 2017
From: cae.mefeagroup at gmail.com (Ionut Predoiu)
Date: Thu, 05 Jan 2017 23:07:28 +1200
Subject: Python for WEB-page !?
References: <604212044@f38.n261.z1.binkp.net>
Message-ID: <3995227808@f38.n261.z1.binkp.net>

Good morning,

Thanks to all for feedback and advice. Because I am a beginner I will read more 
about versions of Python recommended by you.

On the other side I am interested to know if exist some sites which have 
develop platform where can be use for free Python from browsers, without have 
it installed on PC/laptop. As beginner I want to practice from everywhere.

I waiting with higher interest your feedback.

Thanks to all members of community for support and advice. Keep in touch.
Kind regards.



On Thursday, January 5, 2017 at 2:57:23 PM UTC+2, Ionut Predoiu wrote:
> Good afternoon,
>
> I am a beginner in programming language.
> I want to know what version of Python I must to learn to use, beside of basic
language, because I want to integrate in my site 1 page in which users to can 
made calculus based on my formulas already write behind (the users will only 
complete some field, and after push "Calculate" button will see the results in 
form of: table, graphic, and so on ...).
> Please take into account that behind will be more mathematical
equations/formulas, so the speed I think must be take into account.
>
> I waiting with higher interest your feedback.
>
> Thanks to all members of community for support and advice.
> Keep in touch.
> Kind regards.



From irmen.NOSPAM at xs4all.nl  Thu Jan  5 06:49:34 2017
From: irmen.NOSPAM at xs4all.nl (Irmen de Jong)
Date: Thu, 05 Jan 2017 23:49:34 +1200
Subject: Work between multiple processes
References: <2510477911@f38.n261.z1.binkp.net>
Message-ID: <2985338719@f38.n261.z1.binkp.net>

On 4-1-2017 23:14, zxpatric at gmail.com wrote:
> Hi everyone,
>
> I ran into a case that I need to create a work process of an application
(Jython so has to call using java.exe) which will collect the data based on 
what main process indicates.
>
> (1) I tried multiprocessing package, no luck. Java.exe can't be called from
Process class?
>
> (2) I tried subprocess. subprocess.communicate function will wait for the
work process to terminate so to return.
>
>
> either (1) or (2) doesn't work out well. Please suggest.  Global system
queue?
>
> Thanks,
> Patrick.
>


Is it a requirement that the workdf process is also Jython?

If not: you could spawn a Python subprocess that hosts a Pyro4 daemon. 
Utilizing the Pyrolite java client library you can call methods in it from the 
java/jython side.  (Unfortunately it is not yet possible (due to jython 
incompatibilities) to use the full Pyro4 library on the Jython side as well). 
Not sure if it meets your set of requirements but have a look at 
http://pythonhosted.org/Pyro4/
http://pythonhosted.org/Pyro4/pyrolite.html


Irmen



From rhodri at kynesim.co.uk  Thu Jan  5 06:53:15 2017
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Thu, 5 Jan 2017 11:53:15 +0000
Subject: Clickable hyperlinks
In-Reply-To: <005801d2670f$84ab39b0$27b23dae@sambora>
References: <005801d2670f$84ab39b0$27b23dae@sambora>
Message-ID: <763d0613-7c39-d540-5b1d-c2e925638c57@kynesim.co.uk>

On 05/01/17 04:52, Deborah Swanson wrote:
> My original question was in fact whether there was a way to make
> clickable hyperlinks in a console. I was persuaded after about 10
> replies that the answer was no,

Then you were persuaded wrong; the actual answer was "this isn't a 
meaningful question since it's based on incorrect assumptions." 
Translating that to "No" is just as much a mistake as translating it to 
"Yes."

-- 
Rhodri James *-* Kynesim Ltd


From eryksun at gmail.com  Thu Jan  5 07:00:30 2017
From: eryksun at gmail.com (eryk sun)
Date: Fri, 06 Jan 2017 00:00:30 +1200
Subject: Forcing prompt to be on newline when embedding Python with
Message-ID: <2421804724@f38.n261.z1.binkp.net>

On Thu, Jan 5, 2017 at 7:09 AM, H Krishnan <hetchkay at gmail.com> wrote:
>
> I am working on embedding Python in my application.

You forgot to tell us the version of Python that you're embedding.

> I have redirected sys.stdin and sys.stdout to call methods from a Qt TextEdit
> widget. Everything works fine except that the Python prompt does not always
> come in a new line:
>
>>>> dir()
> ['__builtins__', '__doc__', '__name__', '__package__']>>>
>
> Why doesn't the prompt appear in a new line as with the default stdout?

Are you using code.InteractiveConsole / code.interact?

If not, in what mode do you compile, Py_file_input ("exec") or Py_single_input 
("single")? The latter executes PRINT_EXPR:

    >>> dis.dis(compile('1', '', 'single'))
      1           0 LOAD_CONST               0 (1)
                  3 PRINT_EXPR
                  4 LOAD_CONST               1 (None)
                  7 RETURN_VALUE

PRINT_EXPR in turn calls sys.displayhook on the value it pops from the
stack. The default hook writes the repr of the value and a newline to 
sys.stdout, and it also references the value as "_" in the builtins module (2.x 
__builtin__).



From tonycamgar at gmail.com  Thu Jan  5 07:13:24 2017
From: tonycamgar at gmail.com (Antonio Caminero Garcia)
Date: Fri, 06 Jan 2017 00:13:24 +1200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
References: <1078639094@f38.n261.z1.binkp.net>
Message-ID: <532913255@f38.n261.z1.binkp.net>

On Thursday, January 5, 2017 at 9:51:17 AM UTC-8, ArnoB wrote:
> On 02-01-17 12:38, Antonio Caminero Garcia wrote:
> > Hello, I am having a hard time deciding what IDE or IDE-like code editor
should I use. This can be overwhelming.
> >
> > So far, I have used Vim, Sublime, Atom, Eclipse with PyDev, Pycharm,
IntelliJ with Python plugin.
> >
> > The thing with the from-the-scratch full featured IDEs (Eclipse, IntelliJ,
Pycharm) is that they look like a space craft dashboard and that unwarranted 
resources consumption and the unnecessary icons. I want my IDE to be 
minimalistic but powerful. My screen should be mostly ? ?made of code? ? as 
usually happens in Vim, Sublime or Atom. However, Pycharm is really cool and 
python oriented.
> >
> > The problem with Vim is the learning curve, so I know the very basic stuff,
but obviously not enough for coding and I do not have time to learn it, it is a 
pity because there are awesome plugins that turns Vim into a lightweight 
powerful IDE-like. So now it is not an option but I will reconsider it in the 
future, learning little by little. Also, I am not very fan GUI guy if the task 
can be accomplished through the terminal. However, I don? ?t understand why 
people underrate GUIs, that said I normally use shortcuts for the most frequent 
tasks and when I have to do something that is not that frequent then I do it 
with the mouse, for the latter case in vim you would need to look for that 
specific command every time.
> >
> > Sublime is my current and preferred code editor. I installed Anaconda, Git
integration and a couple of additional plugins that make sublime very powerful. 
Also, what I like about sublime compared to the full featured IDEs, besides the 
minimalism, is how you can perform code navigation back and forth so fast, I 
mean this is something that you can also do with the others but for some 
subjective reason I specifically love how sublime does it. The code completion 
in sublime I do not find it very intelligence, the SublimeCodeIntel is better 
than the one that Anaconda uses but the completions are not as verbose as in 
the IDEs.
> >
> > Now, I am thinking about giving a try to Visual Studio Code Edition (take a
look, it sounds good https://marketplace.visualstudio.com/items?itemName=donjay 
amanne.python). I need an editor for professional software development. What 
would you recommend to me?
>
> Hi Antonio,
>
> Just an extra one in case you'll ever want to create
> a nice GUI, then there's also QT Creator:
> https://wiki.qt.io/QtCreator_and_PySide
>
> A very simple but powerful interface a la XCode...
>
> It integrates nicely with PySide:
> https://wiki.qt.io/QtCreator_and_PySide
>
> gr
> Arno

Thanks!



From tonycamgar at gmail.com  Thu Jan  5 07:40:16 2017
From: tonycamgar at gmail.com (Antonio Caminero Garcia)
Date: Fri, 06 Jan 2017 00:40:16 +1200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
References: <2715841046@f38.n261.z1.binkp.net>
Message-ID: <424559356@f38.n261.z1.binkp.net>

On Wednesday, January 4, 2017 at 1:10:04 PM UTC-8, Dietmar Schwertberger wrote:
> On 04.01.2017 07:54, Antonio Caminero Garcia wrote:
> > Unfortunately most of the time I am still using print and input functions.
I know that sucks, I did not use the pdb module, I guess that IDE debuggers 
leverage such module.
> pdb is actually quite useful. On my Windows PCs I can invoke python on
> any .py file with the -i command line switch by right clicking in the
> Explorer and selecting "Debug". Now when the script crashes, I can
> inspect variables without launching a full-scale IDE or starting the
> script from the command line. For such quick fixes I have also a context
> menu entry "Edit" for editing with Pythonwin, which is still quite OK as
> editor and has no licensing restrictions or installation requirements.
> This is a nice option when you deploy your installation to many PCs over
> the network.
I am on MacOS but interesting way of debugging, I will take the idea.
>
> For the print functions vs. debugger:
> The most useful application for a debugger like Wing is not for
> bug-fixing, but to set a break point and then interactively develop on
> the debugger console and with the IDE editor's autocompletion using
> introspection on the live objects. This is very helpful for hardware
> interfacing, network protocols or GUI programs. It really boosted my
> productivity in a way I could not believe before. This is something most
> people forget when they evaluate programming languages. It's not the
> language or syntax that counts, but the overall environment. Probably
> the only other really interactive language and environment is Forth.
>
This is exactly part of the capabilities that I am looking for. I loved you 
brought that up. When I think of an ideal IDE (besides the desirable features 
that I already mentioned previously) as a coworker who is telling me the 
values,types and ids that the objects are getting as you are setting 
breakpoints. So why not use the debugger interactively to develop applications. 
As long as one sets the breakpoints in a meaningful way so you can trace your 
code in a very productive way. Is that what you mean by interactive 
environment?

> > If it happens to be Arduino I normally use a sublime plugin called Stino
> > https://github.com/Robot-Will/Stino
> > (1337 people starred that cool number :D)
> Well, it is CodeWarrior which was quite famous at the time of the 68k Macs.
> The company was bought by Motorola and the IDE is still around for
> Freescale/NXP/Qualcomm microcontrollers like the HCS08 8 bit series.
> Around ten years ago the original CodeWarrior IDE was migrated to
> something Eclipse based.
> When I last evaluated HCS08 vs. Arduino, the HCS08 won due to the better
> debug interface and native USB support. HCS08 is still quite cool, but
> when it comes to documentation, learning curve, tools etc. the Arduinos
> win....
>
>
> Regards,
>
> Dietmar



From tonycamgar at gmail.com  Thu Jan  5 07:46:26 2017
From: tonycamgar at gmail.com (Antonio Caminero Garcia)
Date: Fri, 06 Jan 2017 00:46:26 +1200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
Message-ID: <3454157350@f38.n261.z1.binkp.net>

On Thursday, January 5, 2017 at 12:32:19 PM UTC-8, fpp wrote:
> > On Thu, Jan 5, 2017 at 12:12 PM, Chris Clark <chris.p.clark at ba.com>
> > wrote:
> >> I want an IDE that I can use at work and home, linux and dare I say
> >> windows.
> >> Sublime, had to remove it from my work PC as it is not licensed.
> >> Atom, loved it until it slowed down.
> >> VIM, ok the best if you know vi inside out.
> >> Any JAVA based IDE, just slows up on work PC's due to all the
> >> background stuff that corporates insist they run.
> >> Why can not someone more clever than I fork DrPython and bring it up
> >> to date.
> >> Its is fast, looks great and just does the job ?
>
> I'm suprised no one in this rich thread has even mentioned SciTE :
> http://www.scintilla.org/
>
> Admittedly it's closer to an excellent code editor than a full-blown IDE.
> But it's very lightweight and fast, cross-platform, has superb syntax
> coloring and UTF8 handling, and is highly configurable through its
> configuration file(s) and embedded LUA scripting.
> It's also well maintained : version 1.0 came out in 1999, and the latest
> (3.7.2) is just a week old...
>
> Its IDE side consists mostly of hotkeys to run the interpreter or
> compiler for the language you're editing, with the file in the current
> tab.
> A side pane shows the output (prints, exceptions, errors etc.) of the
> running script.
> A nice touch is that it understands these error messages and makes them
> clickable, taking you to the tab/module/line where the error occurred.
> Also, it can save its current tabs (and their state) to a "session" file
> for later reloading, which is close to the idea of a "project" in most
> IDEs.
> Oh, and it had multi-selection and multi-editing before most of the new
> IDEs out there :-)
>
> Personally that's about all I need for my Python activities, but it can
> be customized much further than I have done : there are "hooks" for other
> external programs than compilers/interpreters, so you can also run a
> linter, debugger or cvs from the editor.
>
> One word of warning: unlike most newer IDEs which tend to be shiny-shiny
> and ful of bells and whistles at first sight, out of the box SciTE is
> *extremely* plain looking (you could even say drab, or ugly :-).
> It is up to you to decide how it should look and what it should do or
> not, through the configuration file.
> Fortunately the documentation is very thorough, and there are a lot of
> examples lying around to be copy/pasted (like a dark theme, LUA scripts
> etc.).
>
> Did I mention it's lightweight ? The archive is about 1.5 MB and it just
> needs unzipping, no installation. May be worth a look if you haven't
> tried it yet...
> fp

Interesting thanks for the link. There are a huge diversity when it comes to 
IDEs/editors. Now I have more than enough options.



From cae.mefeagroup at gmail.com  Thu Jan  5 07:57:12 2017
From: cae.mefeagroup at gmail.com (Ionut Predoiu)
Date: Thu, 5 Jan 2017 04:57:12 -0800 (PST)
Subject: Python for WEB-page !?
Message-ID: <4df49556-ce91-4ca5-8d9e-f505d7f1a1e9@googlegroups.com>

Good afternoon,

I am a beginner in programming language. 
I want to know what version of Python I must to learn to use, beside of basic language, because I want to integrate in my site 1 page in which users to can made calculus based on my formulas already write behind (the users will only complete some field, and after push "Calculate" button will see the results in form of: table, graphic, and so on ...). 
Please take into account that behind will be more mathematical equations/formulas, so the speed I think must be take into account.

I waiting with higher interest your feedback.

Thanks to all members of community for support and advice.
Keep in touch.
Kind regards.


From rustompmody at gmail.com  Thu Jan  5 08:43:07 2017
From: rustompmody at gmail.com (Rustom Mody)
Date: Thu, 5 Jan 2017 05:43:07 -0800 (PST)
Subject: Is there a good process or library for validating changes to XML
 format?
In-Reply-To: <1604a9b9-08ee-40fb-9014-abc2d5d989f1@googlegroups.com>
References: <1604a9b9-08ee-40fb-9014-abc2d5d989f1@googlegroups.com>
Message-ID: <6364315d-77ea-4136-9072-23cb534b7654@googlegroups.com>

On Thursday, January 5, 2017 at 9:02:38 AM UTC+5:30, Sayth Renshaw wrote:
> Afternoon
> 
> Is there a good library or way I could use to check that the author of the XML doc I am using doesn't make small changes to structure over releases?
> 
> Not fully over this with XML but thought that XSD may be what I need, if I search "python XSD" I get a main result for PyXB and generateDS (https://pythonhosted.org/generateDS/). 
> 
> Both seem to be libraries for generating bindings to structures for parsing so maybe I am searching the wrong thing. What is the right thing to search?
> 

Know v little about this. Some links that you can chase:
http://diffxml.sourceforge.net/
http://stackoverflow.com/questions/1871076/are-there-any-free-xml-diff-merge-tools-available

And in python 
https://pypi.python.org/pypi/xmldiff


From porton at narod.ru  Thu Jan  5 08:53:36 2017
From: porton at narod.ru (Victor Porton)
Date: Fri, 06 Jan 2017 01:53:36 +1200
Subject: Python for WEB-page !?
References: <604212044@f38.n261.z1.binkp.net>
Message-ID: <1795172493@f38.n261.z1.binkp.net>

Ionut Predoiu wrote:

> I am a beginner in programming language.
> I want to know what version of Python I must to learn to use, beside of
> basic language, because I want to integrate in my site 1 page in which
> users to can made calculus based on my formulas already write behind (the
> users will only complete some field, and after push "Calculate" button
> will see the results in form of: table, graphic, and so on ...). Please
> take into account that behind will be more mathematical
> equations/formulas, so the speed I think must be take into account.

Consider PyPi. I never used it, but they say, it is faster than usual CPython 
interpreter.

> I waiting with higher interest your feedback.
>
> Thanks to all members of community for support and advice.
> Keep in touch.
> Kind regards.

--
Victor Porton - http://portonvictor.org



From rosuav at gmail.com  Thu Jan  5 10:18:12 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 6 Jan 2017 02:18:12 +1100
Subject: Python for WEB-page !?
In-Reply-To: <4df49556-ce91-4ca5-8d9e-f505d7f1a1e9@googlegroups.com>
References: <4df49556-ce91-4ca5-8d9e-f505d7f1a1e9@googlegroups.com>
Message-ID: <CAPTjJmqTmYi9bx8rypG10C+XviktPR4m3wwaQw6hrm=Dw7i_9A@mail.gmail.com>

On Thu, Jan 5, 2017 at 11:57 PM, Ionut Predoiu <cae.mefeagroup at gmail.com> wrote:
> I am a beginner in programming language.
> I want to know what version of Python I must to learn to use, beside of basic language, because I want to integrate in my site 1 page in which users to can made calculus based on my formulas already write behind (the users will only complete some field, and after push "Calculate" button will see the results in form of: table, graphic, and so on ...).
> Please take into account that behind will be more mathematical equations/formulas, so the speed I think must be take into account.
>

Building a web site can be done with Flask, Django, aiohttp, or a
number of other frameworks. Generating graphs can be done with
matplotlib. Speed won't be a problem - a computer can do a LOT of
mathematical calculations in the time it takes to request something
over the internet.

Have fun exploring!

ChrisA


From python at deborahswanson.net  Thu Jan  5 10:20:26 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Fri, 06 Jan 2017 03:20:26 +1200
Subject: Python for WEB-page !?
Message-ID: <3581984281@f38.n261.z1.binkp.net>

Ionut Predoiu wrote, on January 05, 2017 11:07 PM
>
> Good morning,
>
> Thanks to all for feedback and advice.
> Because I am a beginner I will read more about versions of
> Python recommended by you.
>
> On the other side I am interested to know if exist some sites
> which have develop platform where can be use for free Python
> from browsers, without have it installed on PC/laptop. As
> beginner I want to practice from everywhere.

There's a website called Python Tutor where you can write Python programs and 
it will show you the structures built in memory as it executes. It's  very 
useful for seeing how recursive functions work, or any function or class you 
call. It will also work for simple programs and it has an output console you 
can print to.  (Well, it's more like a print window, but it works.) Very good 
for beginners, I used it all the time when I was first learning, and I still 
use it for recursive functions, since PyCharm doesn't step through recursion in 
a clear way.

http://pythontutor.com/


> I waiting with higher interest your feedback.
>
> Thanks to all members of community for support and advice.
> Keep in touch.
> Kind regards.
>
>
>
> On Thursday, January 5, 2017 at 2:57:23 PM UTC+2, Ionut Predoiu wrote:
> > Good afternoon,
> >
> > I am a beginner in programming language.
> > I want to know what version of Python I must to learn to
> use, beside of basic language, because I want to integrate in
> my site 1 page in which users to can made calculus based on
> my formulas already write behind (the users will only
> complete some field, and after push "Calculate" button will
> see the results in form of: table, graphic, and so on ...).
> > Please take into account that behind will be more
> mathematical equations/formulas, so the speed I think must be
> take into account.
> >
> > I waiting with higher interest your feedback.
> >
> > Thanks to all members of community for support and advice. Keep in
> > touch. Kind regards.
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>



From uri at speedy.net  Thu Jan  5 10:25:48 2017
From: uri at speedy.net (Uri Even-Chen)
Date: Thu, 5 Jan 2017 17:25:48 +0200
Subject: Python for WEB-page !?
In-Reply-To: <CAPTjJmqTmYi9bx8rypG10C+XviktPR4m3wwaQw6hrm=Dw7i_9A@mail.gmail.com>
References: <4df49556-ce91-4ca5-8d9e-f505d7f1a1e9@googlegroups.com>
 <CAPTjJmqTmYi9bx8rypG10C+XviktPR4m3wwaQw6hrm=Dw7i_9A@mail.gmail.com>
Message-ID: <CAMQ2MsH9XN+pC75XCmT_Of4AVxUyza2v0oVQ4VYY1TJUk3D1nQ@mail.gmail.com>

I recommend starting with Python 3, I also use it (3.5.2) for my Django
projects - Speedy Net and Speedy Match.

Uri.


*Uri Even-Chen*
[image: photo] Phone: +972-54-3995700
Email: uri at speedy.net
Website: http://www.speedysoftware.com/uri/en/
<http://www.facebook.com/urievenchen>  <http://plus.google.com/+urievenchen>
  <http://www.linkedin.com/in/urievenchen>  <http://github.com/urievenchen>
<http://twitter.com/urievenchen>

On Thu, Jan 5, 2017 at 5:18 PM, Chris Angelico <rosuav at gmail.com> wrote:

> On Thu, Jan 5, 2017 at 11:57 PM, Ionut Predoiu <cae.mefeagroup at gmail.com>
> wrote:
> > I am a beginner in programming language.
> > I want to know what version of Python I must to learn to use, beside of
> basic language, because I want to integrate in my site 1 page in which
> users to can made calculus based on my formulas already write behind (the
> users will only complete some field, and after push "Calculate" button will
> see the results in form of: table, graphic, and so on ...).
> > Please take into account that behind will be more mathematical
> equations/formulas, so the speed I think must be take into account.
> >
>
> Building a web site can be done with Flask, Django, aiohttp, or a
> number of other frameworks. Generating graphs can be done with
> matplotlib. Speed won't be a problem - a computer can do a LOT of
> mathematical calculations in the time it takes to request something
> over the internet.
>
> Have fun exploring!
>
> ChrisA
> --
> https://mail.python.org/mailman/listinfo/python-list
>


From python at deborahswanson.net  Thu Jan  5 10:28:12 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Fri, 06 Jan 2017 03:28:12 +1200
Subject: Receiving a lot of double messages.
Message-ID: <4289917042@f38.n261.z1.binkp.net>

Antoon Pardon wrote, on January 06, 2017 2:11 AM
>
> Is there something going on with the mailinglist? Because I
> have receive a lot of double messages. One copy is fairly
> normal and is part of the discussion thread, the other is
> completely seperated. -- Antoon Pardon.

Looks to me like the mail server got backed up or jammed and they're flushing 
the mail queue. I haven't seen anything older than Jan. 2 and just started 
seeing some current ones, so I think it's almost over with.



From eryksun at gmail.com  Thu Jan  5 10:54:42 2017
From: eryksun at gmail.com (eryk sun)
Date: Fri, 06 Jan 2017 03:54:42 +1200
Subject: Forcing prompt to be on newline when embedding Python with
Message-ID: <3051026109@f38.n261.z1.binkp.net>

On Fri, Jan 6, 2017 at 1:06 AM, H Krishnan <hetchkay at gmail.com> wrote:
> I tried replacing sys.displayhook with a function that does not print
> newline but the newline still got inserted. So, I am not sure where the
> newline is coming from. In any case, I could override sys.displayhook to add
> a newline at the end and that seems to resolve my problem.

In Python 2 the newline is written depending on the value of 
sys.stdout.softspace. sys.displayhook initially calls Py_FlushLine, which 
resets the file's softspace to 0 via PyFile_SoftSpace and writes a newline if 
the previous value was non-zero. Next displayhook writes the repr, sets the 
softspace to 1 and calls Py_FlushLine again.

The result you're seeing could occur if your filelike object doesn't have a 
dict or a property to allow setting the "softspace" attribute, as the following 
toy example demonstrates:

    import sys

    class File(object):
        def __init__(self, file):
            self._file = file
            self._sp_enabled = True
            self.softspace = 0

        def write(self, string):
            return self._file.write(string)

        def __getattribute__(self, name):
            value = object.__getattribute__(self, name)
            if name == 'softspace':
                if not self._sp_enabled:
                    raise AttributeError
                self._file.write('[get softspace <- %d]\n' % value)
            return value

        def __setattr__(self, name, value):
            if name == 'softspace':
                if not self._sp_enabled:
                    raise AttributeError
                self._file.write('[set softspace -> %d]\n' % value)
            object.__setattr__(self, name, value)

softspace enabled:

    >>> sys.stdout = File(sys.stdout)
    [set softspace -> 0]
    [get softspace <- 0]
    [set softspace -> 0]
    >>> 42
    [get softspace <- 0]
    [set softspace -> 0]
    42[get softspace <- 0]
    [set softspace -> 1]
    [get softspace <- 1]
    [set softspace -> 0]

    [get softspace <- 0]
    [set softspace -> 0]

softspace disabled:

    >>> sys.stdout._sp_enabled = False
    >>> 42
    42>>> 42
    42>>>



From python at rgbaz.eu  Thu Jan  5 12:32:33 2017
From: python at rgbaz.eu (ArnoB)
Date: Thu, 5 Jan 2017 18:32:33 +0100
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
Message-ID: <3dfabd5d-3a45-9fff-4053-fb40e8617154@rgbaz.eu>



On 02-01-17 12:38, Antonio Caminero Garcia wrote:
> Hello, I am having a hard time deciding what IDE or IDE-like code editor should I use. This can be overwhelming.
>
> So far, I have used Vim, Sublime, Atom, Eclipse with PyDev, Pycharm, IntelliJ with Python plugin.
>
> The thing with the from-the-scratch full featured IDEs (Eclipse, IntelliJ, Pycharm) is that they look like a space craft dashboard and that unwarranted resources consumption and the unnecessary icons. I want my IDE to be minimalistic but powerful. My screen should be mostly ?made of code? as usually happens in Vim, Sublime or Atom. However, Pycharm is really cool and python oriented.
>
> The problem with Vim is the learning curve, so I know the very basic stuff, but obviously not enough for coding and I do not have time to learn it, it is a pity because there are awesome plugins that turns Vim into a lightweight powerful IDE-like. So now it is not an option but I will reconsider it in the future, learning little by little. Also, I am not very fan GUI guy if the task can be accomplished through the terminal. However, I don?t understand why people underrate GUIs, that said I normally use shortcuts for the most frequent tasks and when I have to do something that is not that frequent then I do it with the mouse, for the latter case in vim you would need to look for that specific command every time.
>
> Sublime is my current and preferred code editor. I installed Anaconda, Git integration and a couple of additional plugins that make sublime very powerful. Also, what I like about sublime compared to the full featured IDEs, besides the minimalism, is how you can perform code navigation back and forth so fast, I mean this is something that you can also do with the others but for some subjective reason I specifically love how sublime does it. The code completion in sublime I do not find it very intelligence, the SublimeCodeIntel is better than the one that Anaconda uses but the completions are not as verbose as in the IDEs.
>
> Now, I am thinking about giving a try to Visual Studio Code Edition (take a look, it sounds good https://marketplace.visualstudio.com/items?itemName=donjayamanne.python). I need an editor for professional software development. What would you recommend to me?

Hi Antonio,

Just an extra one in case you'll ever want to create
a nice GUI, then there's also QT Creator:
https://wiki.qt.io/QtCreator_and_PySide

A very simple but powerful interface a la XCode...

It integrates nicely with PySide:
https://wiki.qt.io/QtCreator_and_PySide

gr
Arno



From chris.p.clark at ba.com  Thu Jan  5 13:12:14 2017
From: chris.p.clark at ba.com (Chris Clark)
Date: Thu, 5 Jan 2017 18:12:14 +0000
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <3dfabd5d-3a45-9fff-4053-fb40e8617154@rgbaz.eu>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>,
 <3dfabd5d-3a45-9fff-4053-fb40e8617154@rgbaz.eu>
Message-ID: <AM2PR01MB09779DACB5463396F908CF73D2600@AM2PR01MB0977.eurprd01.prod.exchangelabs.com>

I want an IDE that I can use at work and home, linux and dare I say windows.

Sublime, had to remove it from my work PC as it is not licensed.

Atom, loved it until it slowed down.

VIM, ok the best if you know vi inside out.

Any JAVA based IDE, just slows up on work PC's due to all the background stuff that corporates insist they run.

Why can not someone more clever than I fork DrPython and bring it up to date.

Its is fast, looks great and just does the job ?

Its wx, no idea if that is good or bad but it just works.


________________________________
From: Python-list <python-list-bounces+chris.p.clark=ba.com at python.org> on behalf of ArnoB <python at rgbaz.eu>
Sent: 05 January 2017 17:32:33
To: python-list at python.org
Subject: Re: Choosing a Python IDE. what is your Pythonish recommendation? I do not know what to choose.



On 02-01-17 12:38, Antonio Caminero Garcia wrote:
> Hello, I am having a hard time deciding what IDE or IDE-like code editor should I use. This can be overwhelming.
>
> So far, I have used Vim, Sublime, Atom, Eclipse with PyDev, Pycharm, IntelliJ with Python plugin.
>
> The thing with the from-the-scratch full featured IDEs (Eclipse, IntelliJ, Pycharm) is that they look like a space craft dashboard and that unwarranted resources consumption and the unnecessary icons. I want my IDE to be minimalistic but powerful. My screen should be mostly ?made of code? as usually happens in Vim, Sublime or Atom. However, Pycharm is really cool and python oriented.
>
> The problem with Vim is the learning curve, so I know the very basic stuff, but obviously not enough for coding and I do not have time to learn it, it is a pity because there are awesome plugins that turns Vim into a lightweight powerful IDE-like. So now it is not an option but I will reconsider it in the future, learning little by little. Also, I am not very fan GUI guy if the task can be accomplished through the terminal. However, I don?t understand why people underrate GUIs, that said I normally use shortcuts for the most frequent tasks and when I have to do something that is not that frequent then I do it with the mouse, for the latter case in vim you would need to look for that specific command every time.
>
> Sublime is my current and preferred code editor. I installed Anaconda, Git integration and a couple of additional plugins that make sublime very powerful. Also, what I like about sublime compared to the full featured IDEs, besides the minimalism, is how you can perform code navigation back and forth so fast, I mean this is something that you can also do with the others but for some subjective reason I specifically love how sublime does it. The code completion in sublime I do not find it very intelligence, the SublimeCodeIntel is better than the one that Anaconda uses but the completions are not as verbose as in the IDEs.
>
> Now, I am thinking about giving a try to Visual Studio Code Edition (take a look, it sounds good https://marketplace.visualstudio.com/items?itemName=donjayamanne.python). I need an editor for professional software development. What would you recommend to me?

Hi Antonio,

Just an extra one in case you'll ever want to create
a nice GUI, then there's also QT Creator:
https://wiki.qt.io/QtCreator_and_PySide

A very simple but powerful interface a la XCode...

It integrates nicely with PySide:
https://wiki.qt.io/QtCreator_and_PySide

gr
Arno

--
https://mail.python.org/mailman/listinfo/python-list
This message is private and confidential and may also be legally privileged. If you have received this message in error, please email it back to the sender and immediately permanently delete it from your computer system. Please do not read, print, re-transmit, store or act in reliance on it or any attachments. British Airways may monitor email traffic data and also the content of emails, where permitted by law, for the purposes of security and staff training and in order to prevent or detect unauthorised use of the British Airways email system. Virus checking of emails (including attachments) is the responsibility of the recipient. British Airways Plc is a public limited company registered in England and Wales. Registered number: 1777777. Registered office: Waterside, PO Box 365, Harmondsworth, West Drayton, Middlesex, England, UB7 0GB. Additional terms and conditions are available on our website: www.ba.com


From jonas at wielicki.name  Thu Jan  5 13:17:57 2017
From: jonas at wielicki.name (Jonas Wielicki)
Date: Thu, 05 Jan 2017 19:17:57 +0100
Subject: [ANN] aioxmpp 0.7.2 released
Message-ID: <4553913.7XCvY1p1dk@sinistra>

Dear subscribers,

I am pleased to announce the release of aioxmpp 0.7.1 (footnote 1). The
current release can be obtained from GitHub [1] (check out the v0.6.0 tag or
the master branch) or PyPI [2]. The HTML documentation can be found at [3].
Examples can be found in the GitHub repository, in the examples subdirectory.


aioxmpp is a Python library based on asyncio. It implements the client side of
the XMPP protocol (RFC 6120 and others). For a more detailed description of
the package, please review the README of the package on GitHub [1] or on PyPI
[2]. For more information on XMPP, please see [8]. It is licensed under the
terms of the GNU Lesser General Public License Version 3.0 or later.


Version 0.7.2 is a bugfix release. The most severe issue which has been fixed 
is that message stanzas without from attribute caused the stream to crash. 
Other bugfixes included are listed in the changelog [9].


Bugs, feature requests, patches and questions can be directed to either the
aioxmpp mailing list [4], the GitHub issue tracker [5] or the XMPP Multi-User
chat [6], whatever floats your boat. Please direct security-relevant issue
reports directly to me (jonas at wielicki.name), preferrably encrypted using my
GPG public key [7].

best regards and happy-asyncio-ing,
Jonas Wielicki


footnote 1: 0.7.0 and 0.7.1 are functionally identical. I messed up the 0.7.0
release by forgetting to change the license in the setup.py to LGPLv3+, which
made PyPI show the incorrect GPLv3 license.


   [1]: https://github.com/horazont/aioxmpp
   [2]: https://pypi.python.org/pypi/aioxmpp
   [3]: https://docs.zombofant.net/aioxmpp/0.7/
   [4]: https://lists.zombofant.net/mailman/listinfo/aioxmpp-devel
   [5]: https://github.com/horazont/aioxmpp/issues
   [6]: aioxmpp at conference.zombofant.net
   [7]: https://sks-keyservers.net/pks/lookup?op=get&search=0xE5EDE5AC679E300F
        AA5A 78FF 508D 8CF4 F355  F682 E5ED E5AC 679E 300F
   [8]: https://xmpp.org/
   [9]: https://docs.zombofant.net/aioxmpp/0.7/api/
changelog.html#version-0-7-2


From hetchkay at gmail.com  Thu Jan  5 13:36:48 2017
From: hetchkay at gmail.com (H Krishnan)
Date: Fri, 06 Jan 2017 06:36:48 +1200
Subject: Forcing prompt to be on newline when embedding Python with
Message-ID: <595980780@f38.n261.z1.binkp.net>

Thanks for your help.

>
> >
> > I am working on embedding Python in my application.
>
> You forgot to tell us the version of Python that you're embedding.
>
> I am using Python2.7.


> > I have redirected sys.stdin and sys.stdout to call methods from a Qt
> TextEdit
> > widget. Everything works fine except that the Python prompt does not
> always
> > come in a new line:
> >
> >>>> dir()
> > ['__builtins__', '__doc__', '__name__', '__package__']>>>
> >
> > Why doesn't the prompt appear in a new line as with the default stdout?
>
> Are you using code.InteractiveConsole / code.interact?
>
> I am using code.InteractiveConsole().interact().


> If not, in what mode do you compile, Py_file_input ("exec") or
> Py_single_input ("single")? The latter executes PRINT_EXPR:
>
>     >>> dis.dis(compile('1', '', 'single'))
>       1           0 LOAD_CONST               0 (1)
>                   3 PRINT_EXPR
>                   4 LOAD_CONST               1 (None)
>                   7 RETURN_VALUE
>
> PRINT_EXPR in turn calls sys.displayhook on the value it pops from the
> stack. The default hook writes the repr of the value and a newline to
> sys.stdout, and it also references the value as "_" in the builtins
> module (2.x __builtin__).
>

I tried replacing sys.displayhook with a function that does not print newline 
but the newline still got inserted. So, I am not sure where the newline is 
coming from. In any case, I could override sys.displayhook to add a newline at 
the end and that seems to resolve my problem.


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

Thanks,
Krishnan



From marko at pacujo.net  Thu Jan  5 13:46:54 2017
From: marko at pacujo.net (Marko Rauhamaa)
Date: Thu, 05 Jan 2017 20:46:54 +0200
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
 <3dfabd5d-3a45-9fff-4053-fb40e8617154@rgbaz.eu>
 <AM2PR01MB09779DACB5463396F908CF73D2600@AM2PR01MB0977.eurprd01.prod.exchangelabs.com>
 <mailman.263.1483640849.2395.python-list@python.org>
Message-ID: <87fukxtkdd.fsf@elektro.pacujo.net>

Chris Clark <chris.p.clark at ba.com>:

> I want an IDE that I can use at work and home, linux and dare I say
> windows.

I use emacs for all of my typing, including Python programming (and
making this post).


Marko


From nathan.ernst at gmail.com  Thu Jan  5 13:49:09 2017
From: nathan.ernst at gmail.com (Nathan Ernst)
Date: Thu, 5 Jan 2017 12:49:09 -0600
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <AM2PR01MB09779DACB5463396F908CF73D2600@AM2PR01MB0977.eurprd01.prod.exchangelabs.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
 <3dfabd5d-3a45-9fff-4053-fb40e8617154@rgbaz.eu>
 <AM2PR01MB09779DACB5463396F908CF73D2600@AM2PR01MB0977.eurprd01.prod.exchangelabs.com>
Message-ID: <CAPjBxg97jHsnrV9Yc_wKWwLBO1X3M1znjs6jGofVr_gccmN63Q@mail.gmail.com>

Have you looked into Visual Studio Code (https://code.visualstudio.com/)?
I've not used it extensively, and only on Windows, but it's an open source
IDE originated by MS that purportedly works on Windows, Linux & OS X.

It does have pretty decent Python support (haven't tried debugging, but
syntax highlighting works well).

There's also a really good vim extension available.

I tend to prefer vim (or vim extensions) when I can because even though I
probably know less than 10% of vim's capabilities, I'm more productive
using it. I also use the VsVim extension in full proper Visual Studio.

Regards,
Nate

On Thu, Jan 5, 2017 at 12:12 PM, Chris Clark <chris.p.clark at ba.com> wrote:

> I want an IDE that I can use at work and home, linux and dare I say
> windows.
>
> Sublime, had to remove it from my work PC as it is not licensed.
>
> Atom, loved it until it slowed down.
>
> VIM, ok the best if you know vi inside out.
>
> Any JAVA based IDE, just slows up on work PC's due to all the background
> stuff that corporates insist they run.
>
> Why can not someone more clever than I fork DrPython and bring it up to
> date.
>
> Its is fast, looks great and just does the job ?
>
> Its wx, no idea if that is good or bad but it just works.
>
>
> ________________________________
> From: Python-list <python-list-bounces+chris.p.clark=ba.com at python.org>
> on behalf of ArnoB <python at rgbaz.eu>
> Sent: 05 January 2017 17:32:33
> To: python-list at python.org
> Subject: Re: Choosing a Python IDE. what is your Pythonish recommendation?
> I do not know what to choose.
>
>
>
> On 02-01-17 12:38, Antonio Caminero Garcia wrote:
> > Hello, I am having a hard time deciding what IDE or IDE-like code editor
> should I use. This can be overwhelming.
> >
> > So far, I have used Vim, Sublime, Atom, Eclipse with PyDev, Pycharm,
> IntelliJ with Python plugin.
> >
> > The thing with the from-the-scratch full featured IDEs (Eclipse,
> IntelliJ, Pycharm) is that they look like a space craft dashboard and that
> unwarranted resources consumption and the unnecessary icons. I want my IDE
> to be minimalistic but powerful. My screen should be mostly ?made of code?
> as usually happens in Vim, Sublime or Atom. However, Pycharm is really cool
> and python oriented.
> >
> > The problem with Vim is the learning curve, so I know the very basic
> stuff, but obviously not enough for coding and I do not have time to learn
> it, it is a pity because there are awesome plugins that turns Vim into a
> lightweight powerful IDE-like. So now it is not an option but I will
> reconsider it in the future, learning little by little. Also, I am not very
> fan GUI guy if the task can be accomplished through the terminal. However,
> I don?t understand why people underrate GUIs, that said I normally use
> shortcuts for the most frequent tasks and when I have to do something that
> is not that frequent then I do it with the mouse, for the latter case in
> vim you would need to look for that specific command every time.
> >
> > Sublime is my current and preferred code editor. I installed Anaconda,
> Git integration and a couple of additional plugins that make sublime very
> powerful. Also, what I like about sublime compared to the full featured
> IDEs, besides the minimalism, is how you can perform code navigation back
> and forth so fast, I mean this is something that you can also do with the
> others but for some subjective reason I specifically love how sublime does
> it. The code completion in sublime I do not find it very intelligence, the
> SublimeCodeIntel is better than the one that Anaconda uses but the
> completions are not as verbose as in the IDEs.
> >
> > Now, I am thinking about giving a try to Visual Studio Code Edition
> (take a look, it sounds good https://marketplace.visualstudio.com/items?
> itemName=donjayamanne.python). I need an editor for professional software
> development. What would you recommend to me?
>
> Hi Antonio,
>
> Just an extra one in case you'll ever want to create
> a nice GUI, then there's also QT Creator:
> https://wiki.qt.io/QtCreator_and_PySide
>
> A very simple but powerful interface a la XCode...
>
> It integrates nicely with PySide:
> https://wiki.qt.io/QtCreator_and_PySide
>
> gr
> Arno
>
> --
> https://mail.python.org/mailman/listinfo/python-list
> This message is private and confidential and may also be legally
> privileged. If you have received this message in error, please email it
> back to the sender and immediately permanently delete it from your computer
> system. Please do not read, print, re-transmit, store or act in reliance on
> it or any attachments. British Airways may monitor email traffic data and
> also the content of emails, where permitted by law, for the purposes of
> security and staff training and in order to prevent or detect unauthorised
> use of the British Airways email system. Virus checking of emails
> (including attachments) is the responsibility of the recipient. British
> Airways Plc is a public limited company registered in England and Wales.
> Registered number: 1777777. Registered office: Waterside, PO Box 365,
> Harmondsworth, West Drayton, Middlesex, England, UB7 0GB. Additional terms
> and conditions are available on our website: www.ba.com
> --
> https://mail.python.org/mailman/listinfo/python-list
>


From nntp.fpp at spamgourmet.com  Thu Jan  5 15:32:00 2017
From: nntp.fpp at spamgourmet.com (fpp)
Date: 05 Jan 2017 20:32:00 GMT
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
 <3dfabd5d-3a45-9fff-4053-fb40e8617154@rgbaz.eu>
 <AM2PR01MB09779DACB5463396F908CF73D2600@AM2PR01MB0977.eurprd01.prod.exchangelabs.com>
 <CAPjBxg97jHsnrV9Yc_wKWwLBO1X3M1znjs6jGofVr_gccmN63Q@mail.gmail.com>
 <mailman.264.1483642153.2395.python-list@python.org>
Message-ID: <XnsA6F4DB0B81305PaCmAnRDLM@212.27.60.38>

> On Thu, Jan 5, 2017 at 12:12 PM, Chris Clark <chris.p.clark at ba.com>
> wrote: 
>> I want an IDE that I can use at work and home, linux and dare I say
>> windows.
>> Sublime, had to remove it from my work PC as it is not licensed.
>> Atom, loved it until it slowed down.
>> VIM, ok the best if you know vi inside out.
>> Any JAVA based IDE, just slows up on work PC's due to all the
>> background stuff that corporates insist they run.
>> Why can not someone more clever than I fork DrPython and bring it up
>> to date.
>> Its is fast, looks great and just does the job ?

I'm suprised no one in this rich thread has even mentioned SciTE :
http://www.scintilla.org/

Admittedly it's closer to an excellent code editor than a full-blown IDE.
But it's very lightweight and fast, cross-platform, has superb syntax 
coloring and UTF8 handling, and is highly configurable through its 
configuration file(s) and embedded LUA scripting.
It's also well maintained : version 1.0 came out in 1999, and the latest 
(3.7.2) is just a week old...

Its IDE side consists mostly of hotkeys to run the interpreter or 
compiler for the language you're editing, with the file in the current 
tab.
A side pane shows the output (prints, exceptions, errors etc.) of the 
running script.
A nice touch is that it understands these error messages and makes them 
clickable, taking you to the tab/module/line where the error occurred.
Also, it can save its current tabs (and their state) to a "session" file 
for later reloading, which is close to the idea of a "project" in most 
IDEs.
Oh, and it had multi-selection and multi-editing before most of the new 
IDEs out there :-)

Personally that's about all I need for my Python activities, but it can 
be customized much further than I have done : there are "hooks" for other 
external programs than compilers/interpreters, so you can also run a 
linter, debugger or cvs from the editor.

One word of warning: unlike most newer IDEs which tend to be shiny-shiny 
and ful of bells and whistles at first sight, out of the box SciTE is 
*extremely* plain looking (you could even say drab, or ugly :-).
It is up to you to decide how it should look and what it should do or 
not, through the configuration file.
Fortunately the documentation is very thorough, and there are a lot of 
examples lying around to be copy/pasted (like a dark theme, LUA scripts 
etc.).

Did I mention it's lightweight ? The archive is about 1.5 MB and it just 
needs unzipping, no installation. May be worth a look if you haven't 
tried it yet...
fp


From python at deborahswanson.net  Thu Jan  5 17:29:00 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Thu, 5 Jan 2017 14:29:00 -0800
Subject: Clickable hyperlinks
In-Reply-To: <o4kodu$cvb$1@blaine.gmane.org>
Message-ID: <002301d267a3$1d2e27e0$27b23dae@sambora>

Terry Reedy wrote, on January 04, 2017 10:18 PM
> 
> On 1/5/2017 12:11 AM, Deborah Swanson wrote:
> > Terry Reedy wrote, on January 04, 2017 3:58 PM
> 
> >> To have a string interpreted as a clickable link, you send the
string to
> >> software capable of creating a clickable link, plus the information

> >> 'this is a clickable link'*.  There are two ways to tag a string as
a 
> >> link.  One is to use markup around the url in the string itself. 
> >> '<url>' and html are example.  Python provides multiple to make
this 
> >> easy. The other is to tag the string with a separate argument.  
> >> Python provides tkinter, which wraps tk Text widgets, which have a 
> >> powerful tag system.  One can define a Link tag that will a) cause
text 
> >> to be displayed, for instance, blue and underlined and b) cause
clicks on
> >> the text to generate a web request.  One could then use
> >> mytext.insert('insert', 'http://www.example.com', Link) Browser 
> >> must do something similar when they encounter when they encounter 
> >> html link tags.
> >
> > I've actually moved on from my original question to one of opening a

> > url in a browser with python, which seems to be a much more easily 
> > achieved goal.
> 
> > But someone else mentioned tkinter, and I looked at it awhile ago
but 
> > haven't used it for anything. That really could be the way to go if 
> > you want to make clickable links, although you still need some kind
of 
> > internet engine to open the url in a browser.
> 
> IDLE allows a user to add help menu entries that, when clicked on,
open 
> either a local file or an internet url.  For instance, adding the pair

> 'Pillow' and "https://pillow.readthedocs.io/en/latest/" in > the
Settings 
> dialog adda "Pillow" to the help menu (after the standard stuff). 
> Clicking on Help => Pillow opens 
> "https://pillow.readthedocs.io/en/latest/" in the default browswer. 
> IDLE just used the webbrowser module to do this.  No use re-inventing 
> the wheel.  If instead "Pillow" were a link in text, the click handler

> should do something similar.

Yes, unless someone suggests something better, the webbrowser module
looks like the way to go for opening urls in a browser.
> 
> > You say, "There are two ways to tag a string as a link. One is to
use 
> > markup around the url in the string itself. '<url>' and html are 
> > examples.  Python provides multiple ways to make this easy."
> >
> > Can you tell me where I'd begin to look for these? Are they in the 
> > core language, or in packages?
> 
> I was referring to using either % or .format string formatting.  Both 
> are in the core and described somewhere in the Library manual.  '%' 
> should be in the Symbols page of the Index and 'format' on 
> the 'F' page.
> 
> -- 
> Terry Jan Reedy

I looked up % in the Symbols page, but I didn't see any specifier
related to urls. It would be nice if there was something like a %u for
url format, but it isn't in there.

I also tried

	print(<url>"http//python.org"</url>)
		^
but got 'SyntaxError: invalid syntax', with the red arrow pointing at
the first angle bracket. I also tried

	print(<html>"http//python.org"</html>)
            ^
and got the same syntax error, but I'm not sure if that's how you meant
html should be used.

I also tried to look up 'format', but there's no such entry in the
Index. There are a lot of entries that begin with 'format', but none of
them mention urls or anything link related. 'format_field()
(string.Formatter method)' looked like a possibility, but again, I
didn't see anything to format a link with. Maybe I didn't look hard
enough, or didn't see something that _would_ work.

As I've said, at this point I've moved on to directly opening a url in a
browser with the webbrowser module. All I originally wanted to do was be
able to open a url without leaving my IDE while I was debugging data
that has urls in it. Clickable links are really just eye candy that I
don't need if I can get the same result programmatically. But I was
curious whether there are any ways to tag a string as a link in a print
statement. If there are, I didn't find any, but thanks for your
suggestions!

Deborah



From rosuav at gmail.com  Thu Jan  5 17:46:16 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 06 Jan 2017 10:46:16 +1200
Subject: MySQL schema sync or diff
Message-ID: <251176773@f38.n261.z1.binkp.net>

On Thu, Jan 5, 2017 at 11:02 AM, Charles Heizer <ceh329 at gmail.com> wrote:
> I have a MySQL database that is not managed (yet) and I would like to get an
output or diff against my new model file. I'm using flask-sqlalchemy.
>
> Are there any modules that would help me discover the differences so that I
can script a migration to begin using flask-migrate?

I'm not specifically aware of any such tool per se, but what you may want to 
consider is a tool for generating models from existing tables. Then you could 
diff the generated models against your hand-made ones, and build your 
migrations from that. Expect a ton of noise, though.

ChrisA



From irmen.NOSPAM at xs4all.nl  Thu Jan  5 17:49:35 2017
From: irmen.NOSPAM at xs4all.nl (Irmen de Jong)
Date: Thu, 5 Jan 2017 23:49:35 +0100
Subject: Work between multiple processes
In-Reply-To: <892336f7-0adb-431b-aed0-b871d14ac16c@googlegroups.com>
References: <892336f7-0adb-431b-aed0-b871d14ac16c@googlegroups.com>
Message-ID: <586ecd7d$0$21507$e4fe514c@news.xs4all.nl>

On 4-1-2017 23:14, zxpatric at gmail.com wrote:
> Hi everyone,
> 
> I ran into a case that I need to create a work process of an application (Jython so has to call using java.exe) which will collect the data based on what main process indicates. 
> 
> (1) I tried multiprocessing package, no luck. Java.exe can't be called from Process class?
> 
> (2) I tried subprocess. subprocess.communicate function will wait for the work process to terminate so to return.
> 
>  
> either (1) or (2) doesn't work out well. Please suggest.  Global system queue?
> 
> Thanks,
> Patrick.
> 


Is it a requirement that the workdf process is also Jython?

If not: you could spawn a Python subprocess that hosts a Pyro4 daemon.
Utilizing the Pyrolite java client library you can call methods in it from the
java/jython side.  (Unfortunately it is not yet possible (due to jython
incompatibilities) to use the full Pyro4 library on the Jython side as well).
Not sure if it meets your set of requirements but have a look at
http://pythonhosted.org/Pyro4/
http://pythonhosted.org/Pyro4/pyrolite.html


Irmen



From python at deborahswanson.net  Thu Jan  5 17:53:02 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Thu, 5 Jan 2017 14:53:02 -0800
Subject: Clickable hyperlinks
In-Reply-To: <763d0613-7c39-d540-5b1d-c2e925638c57@kynesim.co.uk>
Message-ID: <002801d267a6$78ade4e0$27b23dae@sambora>

Rhodri James wrote, on January 05, 2017 3:53 AM
> 
> On 05/01/17 04:52, Deborah Swanson wrote:
> > My original question was in fact whether there was a way to make 
> > clickable hyperlinks in a console. I was persuaded after about 10 
> > replies that the answer was no,
> 
> Then you were persuaded wrong; the actual answer was "this isn't a 
> meaningful question since it's based on incorrect assumptions." 
> Translating that to "No" is just as much a mistake as 
> translating it to 
> "Yes."
> 
> -- 
> Rhodri James *-* Kynesim Ltd

Actually, your statement "this isn't a meaningful question since it's
based on incorrect assumptions" is false. PyCharm outputs clickable
links to the console, but they aren't web links, they simply link to
lines of code. I'd seen that PyCharm can make links in the console that
aren't web enabled, so it seemed, and in fact it is, reasonable to
assume that it could be done for urls. I just wanted to know if anyone
knew how to do it.

Granted, the suggestion to use tkinter to enable the links came up much
later than in the first 10 or so replies, and since tkinter makes
clickable links possible, that's another reason my question wasn't based
on false assumptions. It simply appears that the early responders to my
question went off on a tangent of what is or is not technologically
possible, and all of the approaches under consideration were in fact
dead ends.

But clickable links turns out to be just eye candy, and the real result
I wanted, which is opening urls in a browser from my IDE, is much more
quickly and easily done programmatically. Although I didn't see this
before I asked my question, and only saw it after reading quite a few
replies.

Perhaps though, I should have said "I was persuaded after about 10
replies that that no one understood what I was asking." But that just
seemed plain rude, so I went with "the answer was no". 



From antoon.pardon at rece.vub.ac.be  Thu Jan  5 18:11:06 2017
From: antoon.pardon at rece.vub.ac.be (Antoon Pardon)
Date: Fri, 06 Jan 2017 11:11:06 +1200
Subject: Receiving a lot of double messages.
Message-ID: <3639766662@f38.n261.z1.binkp.net>

Is there something going on with the mailinglist? Because I have receive a lot 
of double messages. One copy is fairly normal and is part of the discussion 
thread, the other is completely seperated. -- Antoon Pardon.



From rosuav at gmail.com  Thu Jan  5 18:46:17 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 6 Jan 2017 10:46:17 +1100
Subject: MySQL schema sync or diff
In-Reply-To: <68944b94-64d5-41a2-8d85-9a6471f5caab@googlegroups.com>
References: <68944b94-64d5-41a2-8d85-9a6471f5caab@googlegroups.com>
Message-ID: <CAPTjJmoxJ9bE7AOTMRDsape=cr31EqW48Z+QRumsTEgYjUKP4g@mail.gmail.com>

On Thu, Jan 5, 2017 at 11:02 AM, Charles Heizer <ceh329 at gmail.com> wrote:
> I have a MySQL database that is not managed (yet) and I would like to get an output or diff against my new model file. I'm using flask-sqlalchemy.
>
> Are there any modules that would help me discover the differences so that I can script a migration to begin using flask-migrate?

I'm not specifically aware of any such tool per se, but what you may
want to consider is a tool for generating models from existing tables.
Then you could diff the generated models against your hand-made ones,
and build your migrations from that. Expect a ton of noise, though.

ChrisA


From porton at narod.ru  Thu Jan  5 18:53:37 2017
From: porton at narod.ru (Victor Porton)
Date: Fri, 06 Jan 2017 01:53:37 +0200
Subject: Python for WEB-page !?
References: <4df49556-ce91-4ca5-8d9e-f505d7f1a1e9@googlegroups.com>
Message-ID: <o4mm9v$1tr6$1@gioia.aioe.org>

Ionut Predoiu wrote:

> I am a beginner in programming language.
> I want to know what version of Python I must to learn to use, beside of
> basic language, because I want to integrate in my site 1 page in which
> users to can made calculus based on my formulas already write behind (the
> users will only complete some field, and after push "Calculate" button
> will see the results in form of: table, graphic, and so on ...). Please
> take into account that behind will be more mathematical
> equations/formulas, so the speed I think must be take into account.

Consider PyPi. I never used it, but they say, it is faster than usual 
CPython interpreter.

> I waiting with higher interest your feedback.
> 
> Thanks to all members of community for support and advice.
> Keep in touch.
> Kind regards.

-- 
Victor Porton - http://portonvictor.org


From eryksun at gmail.com  Thu Jan  5 19:00:31 2017
From: eryksun at gmail.com (eryk sun)
Date: Fri, 6 Jan 2017 00:00:31 +0000
Subject: Forcing prompt to be on newline when embedding Python with
 stdin/out redirection
In-Reply-To: <CANWsHydFpHy+COb5aVFwePicEVPD1bz=uvU=i8pn9otDvdwOEQ@mail.gmail.com>
References: <CANWsHydFpHy+COb5aVFwePicEVPD1bz=uvU=i8pn9otDvdwOEQ@mail.gmail.com>
Message-ID: <CACL+1attG7g+ddM+kPipXKF9v6LXBxqcvx5oE6jjOkEkcQ1iVw@mail.gmail.com>

On Thu, Jan 5, 2017 at 7:09 AM, H Krishnan <hetchkay at gmail.com> wrote:
>
> I am working on embedding Python in my application.

You forgot to tell us the version of Python that you're embedding.

> I have redirected sys.stdin and sys.stdout to call methods from a Qt TextEdit
> widget. Everything works fine except that the Python prompt does not always
> come in a new line:
>
>>>> dir()
> ['__builtins__', '__doc__', '__name__', '__package__']>>>
>
> Why doesn't the prompt appear in a new line as with the default stdout?

Are you using code.InteractiveConsole / code.interact?

If not, in what mode do you compile, Py_file_input ("exec") or
Py_single_input ("single")? The latter executes PRINT_EXPR:

    >>> dis.dis(compile('1', '', 'single'))
      1           0 LOAD_CONST               0 (1)
                  3 PRINT_EXPR
                  4 LOAD_CONST               1 (None)
                  7 RETURN_VALUE

PRINT_EXPR in turn calls sys.displayhook on the value it pops from the
stack. The default hook writes the repr of the value and a newline to
sys.stdout, and it also references the value as "_" in the builtins
module (2.x __builtin__).


From iranna.gani28 at gmail.com  Thu Jan  5 19:00:32 2017
From: iranna.gani28 at gmail.com (Iranna Mathapati)
Date: Fri, 06 Jan 2017 12:00:32 +1200
Subject: Pexpect
Message-ID: <1324722496@f38.n261.z1.binkp.net>

Hi Team,

How to match latter(caps and small) ,numbers and # symbol in python pexpect.


Thanks,
Iranna M



From breamoreboy at gmail.com  Thu Jan  5 19:19:49 2017
From: breamoreboy at gmail.com (breamoreboy at gmail.com)
Date: Thu, 5 Jan 2017 16:19:49 -0800 (PST)
Subject: Python for WEB-page !?
In-Reply-To: <o4mm9v$1tr6$1@gioia.aioe.org>
References: <4df49556-ce91-4ca5-8d9e-f505d7f1a1e9@googlegroups.com>
 <o4mm9v$1tr6$1@gioia.aioe.org>
Message-ID: <59bd081f-1d98-4d78-83e1-2e0f8df0b553@googlegroups.com>

On Thursday, January 5, 2017 at 11:53:51 PM UTC, Victor Porton wrote:
> Ionut Predoiu wrote:
> 
> > I am a beginner in programming language.
> > I want to know what version of Python I must to learn to use, beside of
> > basic language, because I want to integrate in my site 1 page in which
> > users to can made calculus based on my formulas already write behind (the
> > users will only complete some field, and after push "Calculate" button
> > will see the results in form of: table, graphic, and so on ...). Please
> > take into account that behind will be more mathematical
> > equations/formulas, so the speed I think must be take into account.
> 
> Consider PyPi. I never used it, but they say, it is faster than usual 
> CPython interpreter.
> 

Really?  I'd strongly contrast the Python Package Index https://pypi.python.org/pypi with the Python implementation pypy at http://pypy.org/ :)

> -- 
> Victor Porton - http://portonvictor.org



From torriem at gmail.com  Thu Jan  5 19:41:49 2017
From: torriem at gmail.com (Michael Torrie)
Date: Thu, 5 Jan 2017 17:41:49 -0700
Subject: Python for WEB-page !?
In-Reply-To: <o4mm9v$1tr6$1@gioia.aioe.org>
References: <4df49556-ce91-4ca5-8d9e-f505d7f1a1e9@googlegroups.com>
 <o4mm9v$1tr6$1@gioia.aioe.org>
Message-ID: <a7865193-e8c1-8ce6-3c34-f52590c384f6@gmail.com>

On 01/05/2017 04:53 PM, Victor Porton wrote:
> Ionut Predoiu wrote:
> 
>> I am a beginner in programming language.
>> I want to know what version of Python I must to learn to use, beside of
>> basic language, because I want to integrate in my site 1 page in which
>> users to can made calculus based on my formulas already write behind (the
>> users will only complete some field, and after push "Calculate" button
>> will see the results in form of: table, graphic, and so on ...). Please
>> take into account that behind will be more mathematical
>> equations/formulas, so the speed I think must be take into account.
> 
> Consider PyPi. I never used it, but they say, it is faster than usual 
> CPython interpreter.

With respect, I don't think it's appropriate to direct a python beginner
to PyPi.  Far better to direct him to the relevant resources (like
Django) and focus him on the standard Python interpreter, hopefully
version 3.

Besides that, there's the old expression. Premature optimization is the
root of all evil.  Until Python is shown to be too slow for a given
task, it's premature to think about speedups like Cython or even PyPi.




From torriem at gmail.com  Thu Jan  5 19:48:30 2017
From: torriem at gmail.com (Michael Torrie)
Date: Thu, 5 Jan 2017 17:48:30 -0700
Subject: Python for WEB-page !?
In-Reply-To: <4df49556-ce91-4ca5-8d9e-f505d7f1a1e9@googlegroups.com>
References: <4df49556-ce91-4ca5-8d9e-f505d7f1a1e9@googlegroups.com>
Message-ID: <eba3dc40-05ec-0d17-21c9-0907da4ecaca@gmail.com>

On 01/05/2017 05:57 AM, Ionut Predoiu wrote:
> Good afternoon,
> 
> I am a beginner in programming language. I want to know what version
> of Python I must to learn to use, beside of basic language, because I
> want to integrate in my site 1 page in which users to can made
> calculus based on my formulas already write behind (the users will
> only complete some field, and after push "Calculate" button will see
> the results in form of: table, graphic, and so on ...). Please take
> into account that behind will be more mathematical
> equations/formulas, so the speed I think must be take into account.

While Python can do that, using a web framework to process HTTP requests
and generate HTML to display in the browser, I don't believe Python is
the appropriate language for the task at hand.  Most web sites that do
interactive formula calculations like you describe do it all in the
browser using Javascript.  No need to have a web server do all that
heavy lifting at all.  A simple html file would contain everything you need.

Even if you want to use Python to generate the web page and process
events, you'll still have to master Javascript at some point to make the
webpages more interactive.


From hetchkay at gmail.com  Thu Jan  5 20:06:48 2017
From: hetchkay at gmail.com (H Krishnan)
Date: Fri, 6 Jan 2017 06:36:48 +0530
Subject: Forcing prompt to be on newline when embedding Python with
 stdin/out redirection
In-Reply-To: <CACL+1attG7g+ddM+kPipXKF9v6LXBxqcvx5oE6jjOkEkcQ1iVw@mail.gmail.com>
References: <CANWsHydFpHy+COb5aVFwePicEVPD1bz=uvU=i8pn9otDvdwOEQ@mail.gmail.com>
 <CACL+1attG7g+ddM+kPipXKF9v6LXBxqcvx5oE6jjOkEkcQ1iVw@mail.gmail.com>
Message-ID: <CANWsHydD8mO+Pn7zp=+bEO+QTo4GZxRUNkR0c_OBwDZqMmJHMw@mail.gmail.com>

Thanks for your help.

>
> >
> > I am working on embedding Python in my application.
>
> You forgot to tell us the version of Python that you're embedding.
>
> I am using Python2.7.


> > I have redirected sys.stdin and sys.stdout to call methods from a Qt
> TextEdit
> > widget. Everything works fine except that the Python prompt does not
> always
> > come in a new line:
> >
> >>>> dir()
> > ['__builtins__', '__doc__', '__name__', '__package__']>>>
> >
> > Why doesn't the prompt appear in a new line as with the default stdout?
>
> Are you using code.InteractiveConsole / code.interact?
>
> I am using code.InteractiveConsole().interact().


> If not, in what mode do you compile, Py_file_input ("exec") or
> Py_single_input ("single")? The latter executes PRINT_EXPR:
>
>     >>> dis.dis(compile('1', '', 'single'))
>       1           0 LOAD_CONST               0 (1)
>                   3 PRINT_EXPR
>                   4 LOAD_CONST               1 (None)
>                   7 RETURN_VALUE
>
> PRINT_EXPR in turn calls sys.displayhook on the value it pops from the
> stack. The default hook writes the repr of the value and a newline to
> sys.stdout, and it also references the value as "_" in the builtins
> module (2.x __builtin__).
>

I tried replacing sys.displayhook with a function that does not print
newline but the newline still got inserted. So, I am not sure where the
newline is coming from. In any case, I could override sys.displayhook to
add a newline at the end and that seems to resolve my problem.


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

Thanks,
Krishnan


From hetchkay at gmail.com  Thu Jan  5 22:10:18 2017
From: hetchkay at gmail.com (H Krishnan)
Date: Fri, 06 Jan 2017 15:10:18 +1200
Subject: Forcing prompt to be on newline when embedding Python with
Message-ID: <3419216577@f38.n261.z1.binkp.net>

Hello Mr.Eryk,

Thanks for the detailed explanation. After I added attribute support to my 
extension class for stdio, the problem was resolved.

Regards,
Krishnan


On Fri, Jan 6, 2017 at 9:24 AM, eryk sun <eryksun at gmail.com> wrote:

> On Fri, Jan 6, 2017 at 1:06 AM, H Krishnan <hetchkay at gmail.com> wrote:
> > I tried replacing sys.displayhook with a function that does not print
> > newline but the newline still got inserted. So, I am not sure where the
> > newline is coming from. In any case, I could override sys.displayhook to
> add
> > a newline at the end and that seems to resolve my problem.
>
> In Python 2 the newline is written depending on the value of
> sys.stdout.softspace. sys.displayhook initially calls Py_FlushLine,
> which resets the file's softspace to 0 via PyFile_SoftSpace and writes
> a newline if the previous value was non-zero. Next displayhook writes
> the repr, sets the softspace to 1 and calls Py_FlushLine again.
>
> The result you're seeing could occur if your filelike object doesn't
> have a dict or a property to allow setting the "softspace" attribute,
> as the following toy example demonstrates:
>
>     import sys
>
>     class File(object):
>         def __init__(self, file):
>             self._file = file
>             self._sp_enabled = True
>             self.softspace = 0
>
>         def write(self, string):
>             return self._file.write(string)
>
>         def __getattribute__(self, name):
>             value = object.__getattribute__(self, name)
>             if name == 'softspace':
>                 if not self._sp_enabled:
>                     raise AttributeError
>                 self._file.write('[get softspace <- %d]\n' % value)
>             return value
>
>         def __setattr__(self, name, value):
>             if name == 'softspace':
>                 if not self._sp_enabled:
>                     raise AttributeError
>                 self._file.write('[set softspace -> %d]\n' % value)
>             object.__setattr__(self, name, value)
>
> softspace enabled:
>
>     >>> sys.stdout = File(sys.stdout)
>     [set softspace -> 0]
>     [get softspace <- 0]
>     [set softspace -> 0]
>     >>> 42
>     [get softspace <- 0]
>     [set softspace -> 0]
>     42[get softspace <- 0]
>     [set softspace -> 1]
>     [get softspace <- 1]
>     [set softspace -> 0]
>
>     [get softspace <- 0]
>     [set softspace -> 0]
>
> softspace disabled:
>
>     >>> sys.stdout._sp_enabled = False
>     >>> 42
>     42>>> 42
>     42>>>
> --
> https://mail.python.org/mailman/listinfo/python-list
>



From eryksun at gmail.com  Thu Jan  5 22:54:42 2017
From: eryksun at gmail.com (eryk sun)
Date: Fri, 6 Jan 2017 03:54:42 +0000
Subject: Forcing prompt to be on newline when embedding Python with
 stdin/out redirection
In-Reply-To: <CANWsHydD8mO+Pn7zp=+bEO+QTo4GZxRUNkR0c_OBwDZqMmJHMw@mail.gmail.com>
References: <CANWsHydFpHy+COb5aVFwePicEVPD1bz=uvU=i8pn9otDvdwOEQ@mail.gmail.com>
 <CACL+1attG7g+ddM+kPipXKF9v6LXBxqcvx5oE6jjOkEkcQ1iVw@mail.gmail.com>
 <CANWsHydD8mO+Pn7zp=+bEO+QTo4GZxRUNkR0c_OBwDZqMmJHMw@mail.gmail.com>
Message-ID: <CACL+1av3YvByT4V1s-MpQ51nqsj1HwYNu4U9sC-PV8iU2eFkKA@mail.gmail.com>

On Fri, Jan 6, 2017 at 1:06 AM, H Krishnan <hetchkay at gmail.com> wrote:
> I tried replacing sys.displayhook with a function that does not print
> newline but the newline still got inserted. So, I am not sure where the
> newline is coming from. In any case, I could override sys.displayhook to add
> a newline at the end and that seems to resolve my problem.

In Python 2 the newline is written depending on the value of
sys.stdout.softspace. sys.displayhook initially calls Py_FlushLine,
which resets the file's softspace to 0 via PyFile_SoftSpace and writes
a newline if the previous value was non-zero. Next displayhook writes
the repr, sets the softspace to 1 and calls Py_FlushLine again.

The result you're seeing could occur if your filelike object doesn't
have a dict or a property to allow setting the "softspace" attribute,
as the following toy example demonstrates:

    import sys

    class File(object):
        def __init__(self, file):
            self._file = file
            self._sp_enabled = True
            self.softspace = 0

        def write(self, string):
            return self._file.write(string)

        def __getattribute__(self, name):
            value = object.__getattribute__(self, name)
            if name == 'softspace':
                if not self._sp_enabled:
                    raise AttributeError
                self._file.write('[get softspace <- %d]\n' % value)
            return value

        def __setattr__(self, name, value):
            if name == 'softspace':
                if not self._sp_enabled:
                    raise AttributeError
                self._file.write('[set softspace -> %d]\n' % value)
            object.__setattr__(self, name, value)

softspace enabled:

    >>> sys.stdout = File(sys.stdout)
    [set softspace -> 0]
    [get softspace <- 0]
    [set softspace -> 0]
    >>> 42
    [get softspace <- 0]
    [set softspace -> 0]
    42[get softspace <- 0]
    [set softspace -> 1]
    [get softspace <- 1]
    [set softspace -> 0]

    [get softspace <- 0]
    [set softspace -> 0]

softspace disabled:

    >>> sys.stdout._sp_enabled = False
    >>> 42
    42>>> 42
    42>>>


From iranna.gani28 at gmail.com  Fri Jan  6 01:30:33 2017
From: iranna.gani28 at gmail.com (Iranna Mathapati)
Date: Fri, 6 Jan 2017 12:00:33 +0530
Subject: Pexpect
Message-ID: <CAA4=HD7esswWxjLkL1FiOF+CojNMGkGiRZKEuVtBaapssBZdtA@mail.gmail.com>

Hi Team,

How to match latter(caps and small) ,numbers and # symbol in python pexpect.


Thanks,
Iranna M


From cae.mefeagroup at gmail.com  Fri Jan  6 02:07:29 2017
From: cae.mefeagroup at gmail.com (Ionut Predoiu)
Date: Thu, 5 Jan 2017 23:07:29 -0800 (PST)
Subject: Python for WEB-page !?
In-Reply-To: <4df49556-ce91-4ca5-8d9e-f505d7f1a1e9@googlegroups.com>
References: <4df49556-ce91-4ca5-8d9e-f505d7f1a1e9@googlegroups.com>
Message-ID: <8e976271-c56b-4ac8-bf59-1fd4dd449ca5@googlegroups.com>

Good morning,

Thanks to all for feedback and advice.
Because I am a beginner I will read more about versions of Python recommended by you.

On the other side I am interested to know if exist some sites which have develop platform where can be use for free Python from browsers, without have it installed on PC/laptop. As beginner I want to practice from everywhere.

I waiting with higher interest your feedback. 

Thanks to all members of community for support and advice. 
Keep in touch. 
Kind regards. 



On Thursday, January 5, 2017 at 2:57:23 PM UTC+2, Ionut Predoiu wrote:
> Good afternoon,
> 
> I am a beginner in programming language. 
> I want to know what version of Python I must to learn to use, beside of basic language, because I want to integrate in my site 1 page in which users to can made calculus based on my formulas already write behind (the users will only complete some field, and after push "Calculate" button will see the results in form of: table, graphic, and so on ...). 
> Please take into account that behind will be more mathematical equations/formulas, so the speed I think must be take into account.
> 
> I waiting with higher interest your feedback.
> 
> Thanks to all members of community for support and advice.
> Keep in touch.
> Kind regards.



From tonycamgar at gmail.com  Fri Jan  6 03:13:25 2017
From: tonycamgar at gmail.com (Antonio Caminero Garcia)
Date: Fri, 6 Jan 2017 00:13:25 -0800 (PST)
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <mailman.261.1483638664.2395.python-list@python.org>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
 <3dfabd5d-3a45-9fff-4053-fb40e8617154@rgbaz.eu>
 <mailman.261.1483638664.2395.python-list@python.org>
Message-ID: <da6016b5-8919-47c0-91e3-c05da2ca8ed2@googlegroups.com>

On Thursday, January 5, 2017 at 9:51:17 AM UTC-8, ArnoB wrote:
> On 02-01-17 12:38, Antonio Caminero Garcia wrote:
> > Hello, I am having a hard time deciding what IDE or IDE-like code editor should I use. This can be overwhelming.
> >
> > So far, I have used Vim, Sublime, Atom, Eclipse with PyDev, Pycharm, IntelliJ with Python plugin.
> >
> > The thing with the from-the-scratch full featured IDEs (Eclipse, IntelliJ, Pycharm) is that they look like a space craft dashboard and that unwarranted resources consumption and the unnecessary icons. I want my IDE to be minimalistic but powerful. My screen should be mostly ?made of code? as usually happens in Vim, Sublime or Atom. However, Pycharm is really cool and python oriented.
> >
> > The problem with Vim is the learning curve, so I know the very basic stuff, but obviously not enough for coding and I do not have time to learn it, it is a pity because there are awesome plugins that turns Vim into a lightweight powerful IDE-like. So now it is not an option but I will reconsider it in the future, learning little by little. Also, I am not very fan GUI guy if the task can be accomplished through the terminal. However, I don?t understand why people underrate GUIs, that said I normally use shortcuts for the most frequent tasks and when I have to do something that is not that frequent then I do it with the mouse, for the latter case in vim you would need to look for that specific command every time.
> >
> > Sublime is my current and preferred code editor. I installed Anaconda, Git integration and a couple of additional plugins that make sublime very powerful. Also, what I like about sublime compared to the full featured IDEs, besides the minimalism, is how you can perform code navigation back and forth so fast, I mean this is something that you can also do with the others but for some subjective reason I specifically love how sublime does it. The code completion in sublime I do not find it very intelligence, the SublimeCodeIntel is better than the one that Anaconda uses but the completions are not as verbose as in the IDEs.
> >
> > Now, I am thinking about giving a try to Visual Studio Code Edition (take a look, it sounds good https://marketplace.visualstudio.com/items?itemName=donjayamanne.python). I need an editor for professional software development. What would you recommend to me?
> 
> Hi Antonio,
> 
> Just an extra one in case you'll ever want to create
> a nice GUI, then there's also QT Creator:
> https://wiki.qt.io/QtCreator_and_PySide
> 
> A very simple but powerful interface a la XCode...
> 
> It integrates nicely with PySide:
> https://wiki.qt.io/QtCreator_and_PySide
> 
> gr
> Arno

Thanks!


From tonycamgar at gmail.com  Fri Jan  6 03:40:16 2017
From: tonycamgar at gmail.com (Antonio Caminero Garcia)
Date: Fri, 6 Jan 2017 00:40:16 -0800 (PST)
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <mailman.235.1483564177.2395.python-list@python.org>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
 <64837604-9f3a-806c-d631-fcc352738952@schwertberger.de>
 <mailman.183.1483488743.2395.python-list@python.org>
 <04dc51b5-d546-427f-8ad2-d69284682bdf@googlegroups.com>
 <ededc552-c53f-860a-8ba1-97a58ddeb25d@schwertberger.de>
 <mailman.235.1483564177.2395.python-list@python.org>
Message-ID: <fe8313e9-8ef6-497c-90d5-0dfb9f0b3b34@googlegroups.com>

On Wednesday, January 4, 2017 at 1:10:04 PM UTC-8, Dietmar Schwertberger wrote:
> On 04.01.2017 07:54, Antonio Caminero Garcia wrote:
> > Unfortunately most of the time I am still using print and input functions. I know that sucks, I did not use the pdb module, I guess that IDE debuggers leverage such module.
> pdb is actually quite useful. On my Windows PCs I can invoke python on 
> any .py file with the -i command line switch by right clicking in the 
> Explorer and selecting "Debug". Now when the script crashes, I can 
> inspect variables without launching a full-scale IDE or starting the 
> script from the command line. For such quick fixes I have also a context 
> menu entry "Edit" for editing with Pythonwin, which is still quite OK as 
> editor and has no licensing restrictions or installation requirements. 
> This is a nice option when you deploy your installation to many PCs over 
> the network.
I am on MacOS but interesting way of debugging, I will take the idea.
> 
> For the print functions vs. debugger:
> The most useful application for a debugger like Wing is not for 
> bug-fixing, but to set a break point and then interactively develop on 
> the debugger console and with the IDE editor's autocompletion using 
> introspection on the live objects. This is very helpful for hardware 
> interfacing, network protocols or GUI programs. It really boosted my 
> productivity in a way I could not believe before. This is something most 
> people forget when they evaluate programming languages. It's not the 
> language or syntax that counts, but the overall environment. Probably 
> the only other really interactive language and environment is Forth.
> 
This is exactly part of the capabilities that I am looking for. I loved you brought that up. When I think of an ideal IDE (besides the desirable features that I already mentioned previously) as a coworker who is telling me the values,types and ids that the objects are getting as you are setting breakpoints. So why not use the debugger interactively to develop
applications. As long as one sets the breakpoints in a meaningful way so you can trace your code in a very productive way. Is that what you mean by interactive environment?

> > If it happens to be Arduino I normally use a sublime plugin called Stino
> > https://github.com/Robot-Will/Stino
> > (1337 people starred that cool number :D)
> Well, it is CodeWarrior which was quite famous at the time of the 68k Macs.
> The company was bought by Motorola and the IDE is still around for 
> Freescale/NXP/Qualcomm microcontrollers like the HCS08 8 bit series. 
> Around ten years ago the original CodeWarrior IDE was migrated to 
> something Eclipse based.
> When I last evaluated HCS08 vs. Arduino, the HCS08 won due to the better 
> debug interface and native USB support. HCS08 is still quite cool, but 
> when it comes to documentation, learning curve, tools etc. the Arduinos 
> win....
> 
> 
> Regards,
> 
> Dietmar


From tonycamgar at gmail.com  Fri Jan  6 03:46:27 2017
From: tonycamgar at gmail.com (Antonio Caminero Garcia)
Date: Fri, 6 Jan 2017 00:46:27 -0800 (PST)
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <XnsA6F4DB0B81305PaCmAnRDLM@212.27.60.38>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
 <3dfabd5d-3a45-9fff-4053-fb40e8617154@rgbaz.eu>
 <AM2PR01MB09779DACB5463396F908CF73D2600@AM2PR01MB0977.eurprd01.prod.exchangelabs.com>
 <CAPjBxg97jHsnrV9Yc_wKWwLBO1X3M1znjs6jGofVr_gccmN63Q@mail.gmail.com>
 <mailman.264.1483642153.2395.python-list@python.org>
 <XnsA6F4DB0B81305PaCmAnRDLM@212.27.60.38>
Message-ID: <bac40634-0bdd-44e2-8d2d-c4da4ba6eb03@googlegroups.com>

On Thursday, January 5, 2017 at 12:32:19 PM UTC-8, fpp wrote:
> > On Thu, Jan 5, 2017 at 12:12 PM, Chris Clark <chris.p.clark at ba.com>
> > wrote: 
> >> I want an IDE that I can use at work and home, linux and dare I say
> >> windows.
> >> Sublime, had to remove it from my work PC as it is not licensed.
> >> Atom, loved it until it slowed down.
> >> VIM, ok the best if you know vi inside out.
> >> Any JAVA based IDE, just slows up on work PC's due to all the
> >> background stuff that corporates insist they run.
> >> Why can not someone more clever than I fork DrPython and bring it up
> >> to date.
> >> Its is fast, looks great and just does the job ?
> 
> I'm suprised no one in this rich thread has even mentioned SciTE :
> http://www.scintilla.org/
> 
> Admittedly it's closer to an excellent code editor than a full-blown IDE.
> But it's very lightweight and fast, cross-platform, has superb syntax 
> coloring and UTF8 handling, and is highly configurable through its 
> configuration file(s) and embedded LUA scripting.
> It's also well maintained : version 1.0 came out in 1999, and the latest 
> (3.7.2) is just a week old...
> 
> Its IDE side consists mostly of hotkeys to run the interpreter or 
> compiler for the language you're editing, with the file in the current 
> tab.
> A side pane shows the output (prints, exceptions, errors etc.) of the 
> running script.
> A nice touch is that it understands these error messages and makes them 
> clickable, taking you to the tab/module/line where the error occurred.
> Also, it can save its current tabs (and their state) to a "session" file 
> for later reloading, which is close to the idea of a "project" in most 
> IDEs.
> Oh, and it had multi-selection and multi-editing before most of the new 
> IDEs out there :-)
> 
> Personally that's about all I need for my Python activities, but it can 
> be customized much further than I have done : there are "hooks" for other 
> external programs than compilers/interpreters, so you can also run a 
> linter, debugger or cvs from the editor.
> 
> One word of warning: unlike most newer IDEs which tend to be shiny-shiny 
> and ful of bells and whistles at first sight, out of the box SciTE is 
> *extremely* plain looking (you could even say drab, or ugly :-).
> It is up to you to decide how it should look and what it should do or 
> not, through the configuration file.
> Fortunately the documentation is very thorough, and there are a lot of 
> examples lying around to be copy/pasted (like a dark theme, LUA scripts 
> etc.).
> 
> Did I mention it's lightweight ? The archive is about 1.5 MB and it just 
> needs unzipping, no installation. May be worth a look if you haven't 
> tried it yet...
> fp

Interesting thanks for the link. There are a huge diversity when it comes to IDEs/editors. Now I have more than enough options. 


From hetchkay at gmail.com  Fri Jan  6 04:40:18 2017
From: hetchkay at gmail.com (H Krishnan)
Date: Fri, 6 Jan 2017 15:10:18 +0530
Subject: Forcing prompt to be on newline when embedding Python with
 stdin/out redirection
In-Reply-To: <CACL+1av3YvByT4V1s-MpQ51nqsj1HwYNu4U9sC-PV8iU2eFkKA@mail.gmail.com>
References: <CANWsHydFpHy+COb5aVFwePicEVPD1bz=uvU=i8pn9otDvdwOEQ@mail.gmail.com>
 <CACL+1attG7g+ddM+kPipXKF9v6LXBxqcvx5oE6jjOkEkcQ1iVw@mail.gmail.com>
 <CANWsHydD8mO+Pn7zp=+bEO+QTo4GZxRUNkR0c_OBwDZqMmJHMw@mail.gmail.com>
 <CACL+1av3YvByT4V1s-MpQ51nqsj1HwYNu4U9sC-PV8iU2eFkKA@mail.gmail.com>
Message-ID: <CANWsHyey9GAD_feeHLkpkAaf093s6fpj5ApR=TE7VjdEJqD2yQ@mail.gmail.com>

Hello Mr.Eryk,

Thanks for the detailed explanation. After I added attribute support to my
extension class for stdio, the problem was resolved.

Regards,
Krishnan


On Fri, Jan 6, 2017 at 9:24 AM, eryk sun <eryksun at gmail.com> wrote:

> On Fri, Jan 6, 2017 at 1:06 AM, H Krishnan <hetchkay at gmail.com> wrote:
> > I tried replacing sys.displayhook with a function that does not print
> > newline but the newline still got inserted. So, I am not sure where the
> > newline is coming from. In any case, I could override sys.displayhook to
> add
> > a newline at the end and that seems to resolve my problem.
>
> In Python 2 the newline is written depending on the value of
> sys.stdout.softspace. sys.displayhook initially calls Py_FlushLine,
> which resets the file's softspace to 0 via PyFile_SoftSpace and writes
> a newline if the previous value was non-zero. Next displayhook writes
> the repr, sets the softspace to 1 and calls Py_FlushLine again.
>
> The result you're seeing could occur if your filelike object doesn't
> have a dict or a property to allow setting the "softspace" attribute,
> as the following toy example demonstrates:
>
>     import sys
>
>     class File(object):
>         def __init__(self, file):
>             self._file = file
>             self._sp_enabled = True
>             self.softspace = 0
>
>         def write(self, string):
>             return self._file.write(string)
>
>         def __getattribute__(self, name):
>             value = object.__getattribute__(self, name)
>             if name == 'softspace':
>                 if not self._sp_enabled:
>                     raise AttributeError
>                 self._file.write('[get softspace <- %d]\n' % value)
>             return value
>
>         def __setattr__(self, name, value):
>             if name == 'softspace':
>                 if not self._sp_enabled:
>                     raise AttributeError
>                 self._file.write('[set softspace -> %d]\n' % value)
>             object.__setattr__(self, name, value)
>
> softspace enabled:
>
>     >>> sys.stdout = File(sys.stdout)
>     [set softspace -> 0]
>     [get softspace <- 0]
>     [set softspace -> 0]
>     >>> 42
>     [get softspace <- 0]
>     [set softspace -> 0]
>     42[get softspace <- 0]
>     [set softspace -> 1]
>     [get softspace <- 1]
>     [set softspace -> 0]
>
>     [get softspace <- 0]
>     [set softspace -> 0]
>
> softspace disabled:
>
>     >>> sys.stdout._sp_enabled = False
>     >>> 42
>     42>>> 42
>     42>>>
> --
> https://mail.python.org/mailman/listinfo/python-list
>


From antoon.pardon at rece.vub.ac.be  Fri Jan  6 05:11:07 2017
From: antoon.pardon at rece.vub.ac.be (Antoon Pardon)
Date: Fri, 6 Jan 2017 11:11:07 +0100
Subject: Receiving a lot of double messages.
Message-ID: <1974b8a3-7898-1b0a-a9da-5f0b96719df6@rece.vub.ac.be>

Is there something going on with the mailinglist? Because I have receive
a lot of double messages. One copy is fairly normal and is part of the
discussion thread, the other is completely seperated. -- Antoon Pardon.



From python at deborahswanson.net  Fri Jan  6 06:20:26 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Fri, 6 Jan 2017 03:20:26 -0800
Subject: Python for WEB-page !?
In-Reply-To: <8e976271-c56b-4ac8-bf59-1fd4dd449ca5@googlegroups.com>
Message-ID: <006e01d2680e$e1dc55b0$27b23dae@sambora>

Ionut Predoiu wrote, on January 05, 2017 11:07 PM
> 
> Good morning,
> 
> Thanks to all for feedback and advice.
> Because I am a beginner I will read more about versions of 
> Python recommended by you.
> 
> On the other side I am interested to know if exist some sites 
> which have develop platform where can be use for free Python 
> from browsers, without have it installed on PC/laptop. As 
> beginner I want to practice from everywhere.

There's a website called Python Tutor where you can write Python
programs and it will show you the structures built in memory as it
executes. It's  very useful for seeing how recursive functions work, or
any function or class you call. It will also work for simple programs
and it has an output console you can print to.  (Well, it's more like a
print window, but it works.) Very good for beginners, I used it all the
time when I was first learning, and I still use it for recursive
functions, since PyCharm doesn't step through recursion in a clear way.

http://pythontutor.com/

 
> I waiting with higher interest your feedback. 
> 
> Thanks to all members of community for support and advice. 
> Keep in touch. 
> Kind regards. 
> 
> 
> 
> On Thursday, January 5, 2017 at 2:57:23 PM UTC+2, Ionut Predoiu wrote:
> > Good afternoon,
> > 
> > I am a beginner in programming language.
> > I want to know what version of Python I must to learn to 
> use, beside of basic language, because I want to integrate in 
> my site 1 page in which users to can made calculus based on 
> my formulas already write behind (the users will only 
> complete some field, and after push "Calculate" button will 
> see the results in form of: table, graphic, and so on ...). 
> > Please take into account that behind will be more 
> mathematical equations/formulas, so the speed I think must be 
> take into account.
> > 
> > I waiting with higher interest your feedback.
> > 
> > Thanks to all members of community for support and advice. Keep in 
> > touch. Kind regards.
> 
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 



From python at deborahswanson.net  Fri Jan  6 06:28:13 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Fri, 6 Jan 2017 03:28:13 -0800
Subject: Receiving a lot of double messages.
In-Reply-To: <1974b8a3-7898-1b0a-a9da-5f0b96719df6@rece.vub.ac.be>
Message-ID: <006f01d2680f$f804d4b0$27b23dae@sambora>

Antoon Pardon wrote, on January 06, 2017 2:11 AM
> 
> Is there something going on with the mailinglist? Because I 
> have receive a lot of double messages. One copy is fairly 
> normal and is part of the discussion thread, the other is 
> completely seperated. -- Antoon Pardon.

Looks to me like the mail server got backed up or jammed and they're
flushing the mail queue. I haven't seen anything older than Jan. 2 and
just started seeing some current ones, so I think it's almost over with.



From cae.mefeagroup at gmail.com  Fri Jan  6 06:31:18 2017
From: cae.mefeagroup at gmail.com (Ionut Predoiu)
Date: Fri, 6 Jan 2017 03:31:18 -0800 (PST)
Subject: Python for WEB-page !?
In-Reply-To: <4df49556-ce91-4ca5-8d9e-f505d7f1a1e9@googlegroups.com>
References: <4df49556-ce91-4ca5-8d9e-f505d7f1a1e9@googlegroups.com>
Message-ID: <31394809-e0da-445e-aa9a-30c47ada342e@googlegroups.com>

Good afternoon,

Thank you for advice and promptitude in answer.

Keep in touch for further questions.
Kind regards.

On Thursday, January 5, 2017 at 2:57:23 PM UTC+2, Ionut Predoiu wrote:
> Good afternoon,
> 
> I am a beginner in programming language. 
> I want to know what version of Python I must to learn to use, beside of basic language, because I want to integrate in my site 1 page in which users to can made calculus based on my formulas already write behind (the users will only complete some field, and after push "Calculate" button will see the results in form of: table, graphic, and so on ...). 
> Please take into account that behind will be more mathematical equations/formulas, so the speed I think must be take into account.
> 
> I waiting with higher interest your feedback.
> 
> Thanks to all members of community for support and advice.
> Keep in touch.
> Kind regards.



From rosuav at gmail.com  Fri Jan  6 06:34:58 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 6 Jan 2017 22:34:58 +1100
Subject: Receiving a lot of double messages.
In-Reply-To: <1974b8a3-7898-1b0a-a9da-5f0b96719df6@rece.vub.ac.be>
References: <1974b8a3-7898-1b0a-a9da-5f0b96719df6@rece.vub.ac.be>
Message-ID: <CAPTjJmqWgeYRqiophO6sv5YBd0Jr9wniR1kHPpejq1_q3-kksA@mail.gmail.com>

On Fri, Jan 6, 2017 at 9:11 PM, Antoon Pardon
<antoon.pardon at rece.vub.ac.be> wrote:
> Is there something going on with the mailinglist? Because I have receive
> a lot of double messages. One copy is fairly normal and is part of the
> discussion thread, the other is completely seperated. -- Antoon Pardon.

Yeah, I'm seeing the same. Is the newsgroup gateway feeding back?

ChrisA


From Joaquin.Alzola at lebara.com  Fri Jan  6 06:37:24 2017
From: Joaquin.Alzola at lebara.com (Joaquin Alzola)
Date: Fri, 6 Jan 2017 11:37:24 +0000
Subject: Pexpect
In-Reply-To: <CAA4=HD7esswWxjLkL1FiOF+CojNMGkGiRZKEuVtBaapssBZdtA@mail.gmail.com>
References: <CAA4=HD7esswWxjLkL1FiOF+CojNMGkGiRZKEuVtBaapssBZdtA@mail.gmail.com>
Message-ID: <DB5PR07MB0806DDD2F063F20E7014EF09F0630@DB5PR07MB0806.eurprd07.prod.outlook.com>

> How to match latter(caps and small) ,numbers and # symbol in python pexpect.

With a .*

        child = pexpect.spawnu("ssh cbpapp@%s"% CBP[cust_cbp_server])
        child.setecho(False)
        child.logfile = open("/opt/webapi/logs/delete_accountID.log", "w")
        child.expect(".*assword:")
        child.sendline("XXXX\r")
        child.expect(".*/onip/app/cbpapp>")
        child.sendline("mdsql\r")
        child.expect("SQL>")
        child.sendline("select * from table; \r")
        child.expect("SQL>")
        child.expect("SQL>")

-----

This email is confidential and may be subject to privilege. If you are not the intended recipient, please do not copy or disclose its content but contact the sender immediately upon receipt.


From maillist at schwertberger.de  Fri Jan  6 07:14:52 2017
From: maillist at schwertberger.de (Dietmar Schwertberger)
Date: Fri, 6 Jan 2017 13:14:52 +0100
Subject: Choosing a Python IDE. what is your Pythonish recommendation? I
 do not know what to choose.
In-Reply-To: <fe8313e9-8ef6-497c-90d5-0dfb9f0b3b34@googlegroups.com>
References: <73af2d2d-71d5-450d-a8f8-ef69c016ac8f@googlegroups.com>
 <64837604-9f3a-806c-d631-fcc352738952@schwertberger.de>
 <mailman.183.1483488743.2395.python-list@python.org>
 <04dc51b5-d546-427f-8ad2-d69284682bdf@googlegroups.com>
 <ededc552-c53f-860a-8ba1-97a58ddeb25d@schwertberger.de>
 <mailman.235.1483564177.2395.python-list@python.org>
 <fe8313e9-8ef6-497c-90d5-0dfb9f0b3b34@googlegroups.com>
Message-ID: <c0158d13-3e34-2a54-7fd6-3f0118442820@schwertberger.de>

On 06.01.2017 09:40, Antonio Caminero Garcia wrote:
> So why not use the debugger interactively to develop
> applications. As long as one sets the breakpoints in a meaningful way so you can trace your code in a very productive way. Is that what you mean by interactive environment?
Well, not exactly. Maybe have a look at the video "Interactive Debug 
Probe" at
https://wingware.com/wingide/debugger

Regards,

Dietmar



From steve+python at pearwood.info  Fri Jan  6 08:03:37 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Sat, 07 Jan 2017 00:03:37 +1100
Subject: The hardest problem in computer science...
Message-ID: <586f95ac$0$1589$c3e8da3$5496439d@news.astraweb.com>

The second hardest problem in computer science is cache invalidation.

The *hardest* problem is naming things.

In a hierarchical tree view widget that displays items like this:


    Fiction
    ?? Fantasy
    ?  ?? Terry Pratchett
    ?  ?  ?? Discworld
    ?  ?  ?  ?? Wyrd Sisters
    ?  ?  ?  ?? Carpe Jugulum
    ?  ?  ?? Dodger
    ?  ?? JK Rowling
    ?     ?? Harry Potter And The Philosopher's Stone
    ?? Science Fiction
    ?  ?? Connie Willis
    ?  ?  ?? To Say Nothing Of The Dog
    ?  ?? Neal Stephenson
    ?     ?? Snow Crash
    ?? Horror
       ?? Stephen King
          ?? Salem's Lot
          ?? It


what do we call the vertical and horizontal line elements? I want to make
them configurable, which means the user has to be able to pass an argument
that specifies them. I have names for the individual components:

XXX = namedtuple("XXX", "vline tee corner")

default_YYY = XXX("?  ", "?? ", "?? ")
bold_YYY = XXX("?  ", "?? ", "?? ")
ascii_YYY = XXX("|  ", "|- ", "+- ")

def draw_tree(tree, YYY=default_YYY):
    ...


but what do I call XXX and YYY?


Seriously-considering-just-hard-coding-them-as-magic-constants-ly y'rs,


-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From muhammadasad254 at gmail.com  Fri Jan  6 08:13:21 2017
From: muhammadasad254 at gmail.com (muhammadasad254 at gmail.com)
Date: Fri, 6 Jan 2017 05:13:21 -0800 (PST)
Subject: "paperpk" "paper pk" "paperpk.com" "express newspaper" "newspaper
 classified ads" "dawn jobs ads" "jang newspaper" "dawn jobs" "jang
 jobs ads" "nawaiwaqt" "classified ads" on   www.npjobs.blogspot.com
In-Reply-To: <2d475602-e3b6-4d31-9a3b-55429df58984@y32g2000prd.googlegroups.com>
References: <2d475602-e3b6-4d31-9a3b-55429df58984@y32g2000prd.googlegroups.com>
Message-ID: <5ec651f9-6be5-45cd-92fe-170d30a2e441@googlegroups.com>

this a all of facek you are veiw the latest post today newspaperp on view <a href='http://governmentjobs.inpakistan.com.pk/category/paperpkads/'>paperpkads</a>.


From dan at tombstonezero.net  Fri Jan  6 08:44:28 2017
From: dan at tombstonezero.net (Dan Sommers)
Date: Fri, 6 Jan 2017 13:44:28 -0000 (UTC)
Subject: The hardest problem in computer science...
References: <586f95ac$0$1589$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <o4o6vs$tqh$1@dont-email.me>

On Sat, 07 Jan 2017 00:03:37 +1100, Steve D'Aprano wrote:

> The *hardest* problem is naming things.

> 
>     Fiction
>     ?? Fantasy
>     ?  ?? Terry Pratchett
>     ?  ?  ?? Discworld
>     ?  ?  ?  ?? Wyrd Sisters
>     ?  ?  ?  ?? Carpe Jugulum

[...]

> what do we call the vertical and horizontal line elements? I want to make
> them configurable, which means the user has to be able to pass an argument
> that specifies them ...

pstree(1) (https://en.wikipedia.org/wiki/Pstree,
http://man7.org/linux/man-pages/man1/pstree.1.html) calls them "line
drawing characters," and took a slightly different approach (I think) to
the command line argument(s):

The default is ASCII, or you can specify -G to specify the VT100 line
drawing characters (G for Graphic, I assume), or you can specify -U for
the UTF-8 line drawing characters.

Dan


From python.list at tim.thechases.com  Fri Jan  6 09:01:28 2017
From: python.list at tim.thechases.com (Tim Chase)
Date: Fri, 6 Jan 2017 08:01:28 -0600
Subject: The hardest problem in computer science...
In-Reply-To: <o4o6vs$tqh$1@dont-email.me>
References: <586f95ac$0$1589$c3e8da3$5496439d@news.astraweb.com>
 <o4o6vs$tqh$1@dont-email.me>
Message-ID: <20170106080128.6e45f019@bigbox.christie.dr>

On 2017-01-06 13:44, Dan Sommers wrote:
> On Sat, 07 Jan 2017 00:03:37 +1100, Steve D'Aprano wrote:
> > what do we call the vertical and horizontal line elements? I want
> > to make them configurable, which means the user has to be able to
> > pass an argument that specifies them ...
> 
> pstree(1) calls them "line drawing characters,"

I second the use of "drawing characters" as I've seen them described
as "line-drawing characters", "box drawing characters", or "tree
drawing characters" depending on the context.

Wikipedia seems to favor "box drawing characters"

  https://en.wikipedia.org/wiki/Box-drawing_character

Takes me back to my ascii-art days on BBSes. :-)

-tkc







From __peter__ at web.de  Fri Jan  6 09:04:02 2017
From: __peter__ at web.de (Peter Otten)
Date: Fri, 06 Jan 2017 15:04:02 +0100
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
Message-ID: <o4o84h$klm$1@blaine.gmane.org>

Example: you are looking for the minimum absolute value in a series of 
integers. As soon as you encounter the first 0 it's unnecessary extra work 
to check the remaining values, but the builtin min() will continue.

The solution is a minimum function that allows the user to specify a stop 
value:

>>> from itertools import count, chain
>>> stopmin(chain(reversed(range(10)), count()), key=abs, stop=0)
0

How would you implement stopmin()?

Currently I raise an exception in the key function:

class Stop(Exception):
    pass

def stopmin(items, key, stop):
    """
    >>> def g():
    ...     for i in reversed(range(10)):
    ...         print(10*i)
    ...         yield str(i)
    >>> stopmin(g(), key=int, stop=5)
    90
    80
    70
    60
    50
    '5'
    """
    def key2(value):
        result = key(value)
        if result <= stop:
            raise Stop(value)
        return result
    try:
        return min(items, key=key2)
    except Stop as stop:
        return stop.args[0]




From alain at universite-de-strasbourg.fr.invalid  Fri Jan  6 09:08:07 2017
From: alain at universite-de-strasbourg.fr.invalid (Alain Ketterlin)
Date: Fri, 06 Jan 2017 15:08:07 +0100
Subject: The hardest problem in computer science...
References: <586f95ac$0$1589$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <87y3yo703c.fsf@universite-de-strasbourg.fr.invalid>

Steve D'Aprano <steve+python at pearwood.info> writes:

[...]
>     Fiction
>     ?? Fantasy
>     ?  ?? Terry Pratchett
>     ?  ?  ?? Discworld
>     ?  ?  ?  ?? Wyrd Sisters
>     ?  ?  ?  ?? Carpe Jugulum
>     ?  ?  ?? Dodger
>     ?  ?? JK Rowling
[...]
> what do we call the vertical and horizontal line elements?

Box-drawing characters. At least that's how Unicode calls them. Even if
you don't draw boxes...

https://en.wikipedia.org/wiki/Box-drawing_character

-- Alain.


From skip.montanaro at gmail.com  Fri Jan  6 09:12:10 2017
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Fri, 6 Jan 2017 08:12:10 -0600
Subject: The hardest problem in computer science...
In-Reply-To: <20170106080128.6e45f019@bigbox.christie.dr>
References: <586f95ac$0$1589$c3e8da3$5496439d@news.astraweb.com>
 <o4o6vs$tqh$1@dont-email.me> <20170106080128.6e45f019@bigbox.christie.dr>
Message-ID: <CANc-5Uy=fdBF1uU21J23yRPqto1b6WM-qGtRvfYJTRApxVJr=A@mail.gmail.com>

"VT52 special graphics characters", anyone? Credit where credit is due. Who
hasn't borked their output and wound up with their VT(52|100) in graphics
mode? :-)

https://en.wikipedia.org/wiki/VT52

Skip


From ethan at stoneleaf.us  Fri Jan  6 10:37:40 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Fri, 06 Jan 2017 07:37:40 -0800
Subject: The hardest problem in computer science...
In-Reply-To: <586f95ac$0$1589$c3e8da3$5496439d@news.astraweb.com>
References: <586f95ac$0$1589$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <586FB9C4.6000505@stoneleaf.us>

On 01/06/2017 05:03 AM, Steve D'Aprano wrote:

> what do we call the vertical and horizontal line elements? I want to make
> them configurable, which means the user has to be able to pass an argument
> that specifies them. I have names for the individual components:
>
> XXX = namedtuple("XXX", "vline tee corner")
>
> default_YYY = XXX("?  ", "?? ", "?? ")
> bold_YYY = XXX("?  ", "?? ", "?? ")
> ascii_YYY = XXX("|  ", "|- ", "+- ")
>
> def draw_tree(tree, YYY=default_YYY):
>      ...
>
> but what do I call XXX and YYY?

Looks like horizontal, vertical, and corner are as groups -- so I would call YYY "style" and XXX "default", "bold", and "ascii".

--
~Ethan~


From mal at python.org  Fri Jan  6 11:01:00 2017
From: mal at python.org (M.-A. Lemburg)
Date: Fri, 6 Jan 2017 17:01:00 +0100
Subject: ANN: Python Events Calendar - Please submit your 2017 events
Message-ID: <855935bd-f516-0778-b711-8b35530825c3@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 2017 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 https://www.python.org/events/ and
http://pycon.org/. There's also a map mashup to show events near
you or get an overview of what currently going in the Python
community:

   http://lmorillas.github.io/python_events/

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, the calendars have proven to be a great tool
for the Python community to connect, with more than 250 conferences
and more than a hundred of user group events listed since 2012.

We would therefore like to encourage everyone to submit their
2017 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#Submitting_an_Event

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
Python Software Foundation
http://www.python.org/psf/
http://www.malemburg.com/



From zxpatric at gmail.com  Fri Jan  6 14:03:13 2017
From: zxpatric at gmail.com (Patrick Zhou)
Date: Fri, 6 Jan 2017 11:03:13 -0800 (PST)
Subject: Work between multiple processes
In-Reply-To: <586ecd7d$0$21507$e4fe514c@news.xs4all.nl>
References: <892336f7-0adb-431b-aed0-b871d14ac16c@googlegroups.com>
 <586ecd7d$0$21507$e4fe514c@news.xs4all.nl>
Message-ID: <a4bb5fce-0f7e-445a-b20f-4cb86a0deb5e@googlegroups.com>

On Thursday, January 5, 2017 at 5:49:46 PM UTC-5, Irmen de Jong wrote:
> On 4-1-2017 23:14, zxpatric at gmail.com wrote:
> > Hi everyone,
> > 
> > I ran into a case that I need to create a work process of an application (Jython so has to call using java.exe) which will collect the data based on what main process indicates. 
> > 
> > (1) I tried multiprocessing package, no luck. Java.exe can't be called from Process class?
> > 
> > (2) I tried subprocess. subprocess.communicate function will wait for the work process to terminate so to return.
> > 
> >  
> > either (1) or (2) doesn't work out well. Please suggest.  Global system queue?
> > 
> > Thanks,
> > Patrick.
> > 
> 
> 
> Is it a requirement that the workdf process is also Jython?
> 
> If not: you could spawn a Python subprocess that hosts a Pyro4 daemon.
> Utilizing the Pyrolite java client library you can call methods in it from the
> java/jython side.  (Unfortunately it is not yet possible (due to jython
> incompatibilities) to use the full Pyro4 library on the Jython side as well).
> Not sure if it meets your set of requirements but have a look at
> http://pythonhosted.org/Pyro4/
> http://pythonhosted.org/Pyro4/pyrolite.html
> 
> 
> Irmen


Thanks Irmen. I think that could be the solution I am looking for. The main process will be native python so it can be used to host a pyro daemon even with lock. The jython will be a subprocess that takes the daemon's uri and use the pyrolite library to make the communication. The only trouble is that I will have to involve two more java libraries but I don't think it is a big of deal. Will try it and post the source code if possible.


From jussi.piitulainen at helsinki.fi  Fri Jan  6 14:21:32 2017
From: jussi.piitulainen at helsinki.fi (Jussi Piitulainen)
Date: Fri, 06 Jan 2017 21:21:32 +0200
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
Message-ID: <lf57f68805f.fsf@ling.helsinki.fi>

Peter Otten writes:

> Example: you are looking for the minimum absolute value in a series of 
> integers. As soon as you encounter the first 0 it's unnecessary extra work 
> to check the remaining values, but the builtin min() will continue.
>
> The solution is a minimum function that allows the user to specify a stop 
> value:
>
>>>> from itertools import count, chain
>>>> stopmin(chain(reversed(range(10)), count()), key=abs, stop=0)
> 0
>
> How would you implement stopmin()?

Only let min see the data up to, but including, the stop value:

from itertools import groupby

def takeuntil(data, pred):
    '''Take values from data until and including the first that
    satisfies pred (until data is exhausted if none does).'''
    for kind, group in groupby(data, pred):
        if kind:
            yield next(group)
            break
        else:
            yield from group

def stopmin(data, key, stop):
    return min(takeuntil(data, lambda o : key(o) == stop),
               key = key)

data = '31415926'
for stop in range(5):
    print(stop,
          '=>', repr(''.join(takeuntil(data, lambda o : int(o) == stop))),
          '=>', repr(stopmin(data, int, stop)))

# 0 => '31415926' => '1'
# 1 => '31' => '1'
# 2 => '3141592' => '1'
# 3 => '3' => '3'
# 4 => '314' => '1'

from itertools import count, chain
print(stopmin(chain(reversed(range(10)), count()), key=abs, stop=0))
print(stopmin(chain(reversed(range(10)), count()), key=abs, stop=3))

# 0
# 3


From wolfgang.maier at biologie.uni-freiburg.de  Fri Jan  6 15:06:58 2017
From: wolfgang.maier at biologie.uni-freiburg.de (Wolfgang Maier)
Date: Fri, 6 Jan 2017 21:06:58 +0100
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
In-Reply-To: <o4o84h$klm$1@blaine.gmane.org>
References: <o4o84h$klm$1@blaine.gmane.org>
Message-ID: <072dfa54-0e8f-ee1e-b822-ad96300a1e6b@biologie.uni-freiburg.de>

On 1/6/2017 15:04, Peter Otten wrote:
> Example: you are looking for the minimum absolute value in a series of
> integers. As soon as you encounter the first 0 it's unnecessary extra work
> to check the remaining values, but the builtin min() will continue.
>
> The solution is a minimum function that allows the user to specify a stop
> value:
>
>>>> from itertools import count, chain
>>>> stopmin(chain(reversed(range(10)), count()), key=abs, stop=0)
> 0
>
> How would you implement stopmin()?
>

How about:

def stopmin (iterable, key, stop):
     def take_until ():
         for e in iterable:
             yield e
             if key(e) <= stop:
                 break
     return min(take_until(), key=key)

?



From wolfgang.maier at biologie.uni-freiburg.de  Fri Jan  6 15:06:58 2017
From: wolfgang.maier at biologie.uni-freiburg.de (Wolfgang Maier)
Date: Fri, 6 Jan 2017 21:06:58 +0100
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
In-Reply-To: <o4o84h$klm$1@blaine.gmane.org>
References: <o4o84h$klm$1@blaine.gmane.org>
Message-ID: <072dfa54-0e8f-ee1e-b822-ad96300a1e6b@biologie.uni-freiburg.de>

On 1/6/2017 15:04, Peter Otten wrote:
> Example: you are looking for the minimum absolute value in a series of
> integers. As soon as you encounter the first 0 it's unnecessary extra work
> to check the remaining values, but the builtin min() will continue.
>
> The solution is a minimum function that allows the user to specify a stop
> value:
>
>>>> from itertools import count, chain
>>>> stopmin(chain(reversed(range(10)), count()), key=abs, stop=0)
> 0
>
> How would you implement stopmin()?
>

How about:

def stopmin (iterable, key, stop):
     def take_until ():
         for e in iterable:
             yield e
             if key(e) <= stop:
                 break
     return min(take_until(), key=key)

?


From jf_byrnes at comcast.net  Fri Jan  6 16:44:53 2017
From: jf_byrnes at comcast.net (jim)
Date: Fri, 6 Jan 2017 15:44:53 -0600
Subject: Using sudo with pip3?
Message-ID: <o4p34h$3ci$1@blaine.gmane.org>

Setting up a new computer to run Ubuntu 16.04. Started using pip3 to 
install all the python stuff I had on the old machine and got this message:

jfb at jims-1604:~$ sudo pip3 install matplotlib
[sudo] password for jfb:
The directory '/home/jfb/.cache/pip/http' or its parent directory is not 
owned by the current user and the cache has been disabled. Please check 
the permissions and owner of that directory. If executing pip with sudo, 
you may want sudo's -H flag.

I (jfb) own the directory in question.

I used sudo because I recall needing to use it on the old machine to get 
something to install. So is it necessary or even desirable to use sudo 
with pip3?

Thanks,  Jim



From grant.b.edwards at gmail.com  Fri Jan  6 16:55:52 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Fri, 6 Jan 2017 21:55:52 +0000 (UTC)
Subject: Receiving a lot of double messages.
References: <3639766662@f38.n261.z1.binkp.net>
Message-ID: <o4p3p8$o5f$1@blaine.gmane.org>

On 2017-01-05, Antoon Pardon <antoon.pardon at rece.vub.ac.be> wrote:

> Is there something going on with the mailinglist? Because I have receive a lot 
> of double messages. One copy is fairly normal and is part of the discussion 
> thread, the other is completely seperated. -- Antoon Pardon.

Yep, there are a _lot_ of duplicate messages showing up on gmane's
NNTP server.  I would guess around 50-100 of them in the past day.
Entire chunks of long threads comprising 20-30 posts seem to be
duplicated in some cases.  In other cases, they're just individual
posts that seem to be detached from their original threads.

Something is seriously broken somewhere...

-- 
Grant Edwards               grant.b.edwards        Yow! I want a VEGETARIAN
                                  at               BURRITO to go ... with
                              gmail.com            EXTRA MSG!!



From contact at clintmoyer.com  Fri Jan  6 17:14:57 2017
From: contact at clintmoyer.com (Clint Moyer)
Date: Fri, 06 Jan 2017 22:14:57 +0000
Subject: Using sudo with pip3?
In-Reply-To: <o4p34h$3ci$1@blaine.gmane.org>
References: <o4p34h$3ci$1@blaine.gmane.org>
Message-ID: <CAO6+pg+fLTszLEgKxwGbPJT7L6EOSXochY=UTPsOjiC=HWSp=A@mail.gmail.com>

>From Ubuntu, why not try:

sudo apt-get install python-matplotlib

-Clint

On Fri, Jan 6, 2017 at 3:09 PM jim <jf_byrnes at comcast.net> wrote:

> Setting up a new computer to run Ubuntu 16.04. Started using pip3 to
>
> install all the python stuff I had on the old machine and got this message:
>
>
>
> jfb at jims-1604:~$ sudo pip3 install matplotlib
>
> [sudo] password for jfb:
>
> The directory '/home/jfb/.cache/pip/http' or its parent directory is not
>
> owned by the current user and the cache has been disabled. Please check
>
> the permissions and owner of that directory. If executing pip with sudo,
>
> you may want sudo's -H flag.
>
>
>
> I (jfb) own the directory in question.
>
>
>
> I used sudo because I recall needing to use it on the old machine to get
>
> something to install. So is it necessary or even desirable to use sudo
>
> with pip3?
>
>
>
> Thanks,  Jim
>
>
>
> --
>
> https://mail.python.org/mailman/listinfo/python-list
>
>


From cs at zip.com.au  Fri Jan  6 17:36:44 2017
From: cs at zip.com.au (cs at zip.com.au)
Date: Sat, 7 Jan 2017 09:36:44 +1100
Subject: Using sudo with pip3?
In-Reply-To: <o4p34h$3ci$1@blaine.gmane.org>
References: <o4p34h$3ci$1@blaine.gmane.org>
Message-ID: <20170106223644.GA71783@cskk.homeip.net>

On 06Jan2017 15:44, jim <jf_byrnes at comcast.net> wrote:
>Setting up a new computer to run Ubuntu 16.04. Started using pip3 to 
>install all the python stuff I had on the old machine and got this 
>message:
>
>jfb at jims-1604:~$ sudo pip3 install matplotlib
>[sudo] password for jfb:
>The directory '/home/jfb/.cache/pip/http' or its parent directory is 
>not owned by the current user and the cache has been disabled. Please 
>check the permissions and owner of that directory. If executing pip 
>with sudo, you may want sudo's -H flag.
>
>I (jfb) own the directory in question.
>
>I used sudo because I recall needing to use it on the old machine to 
>get something to install. So is it necessary or even desirable to use sudo 
>with pip3?

I would not, unless I were specificly trying to install into the system's 
python3 libraries. That will inherently fight with any vendor (Unbuntu) 
supplied packages that come through apt-get.

Instead I would make myself a virtualenv _based off the system python3_ and use 
the venv's pip to install extra packages. Not using sudo. They will land in 
your virtualenv directory's lib area, be entirely owned and controlled by you, 
and not have any complications that come with sudo.

Then just symlink the virtualenv's "python3" into your own $HOME/bin and 
whenever you invoke "python3" it will run the virtualenv one, getting all the 
package goodness you have added.

An important sysadmin rule of thumb: use apt (or yum etc, depending on distro) 
as root to install vendor supplied packages. And install your owon packages _as 
you_ in another area, _not_ in the system managed area. Virtualenv makes this 
very easy to do for Python.

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


From cs at zip.com.au  Fri Jan  6 18:00:13 2017
From: cs at zip.com.au (Cameron Simpson)
Date: Sat, 7 Jan 2017 10:00:13 +1100
Subject: Pexpect
In-Reply-To: <DB5PR07MB0806DDD2F063F20E7014EF09F0630@DB5PR07MB0806.eurprd07.prod.outlook.com>
References: <DB5PR07MB0806DDD2F063F20E7014EF09F0630@DB5PR07MB0806.eurprd07.prod.outlook.com>
Message-ID: <20170106230012.GA7100@cskk.homeip.net>

On 06Jan2017 11:37, Joaquin Alzola <Joaquin.Alzola at lebara.com> wrote:
>Iranna Mathapati <iranna.gani28 at gmail.com> asked:
>> How to match latter(caps and small) ,numbers and # symbol in python pexpect.
>
>With a .*

Ugh. Please not. Expect() accepts a nongreedy regular expression. ".*" is the 
lazy "match absolutely anything" pattern. Generally overused and imprecise.  
Iranna Mathapati knows what to look for.

See the documentation for the re module, specificly the regular expression 
syntax:

  https://docs.python.org/3/library/re.html#regular-expression-syntax

To match letters, digits and "#", try:

  [0-9a-zA-Z#]*

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


From contact at clintmoyer.com  Fri Jan  6 18:03:05 2017
From: contact at clintmoyer.com (Clint Moyer)
Date: Fri, 06 Jan 2017 23:03:05 +0000
Subject: Using sudo with pip3?
In-Reply-To: <20170106223644.GA71783@cskk.homeip.net>
References: <o4p34h$3ci$1@blaine.gmane.org>
 <20170106223644.GA71783@cskk.homeip.net>
Message-ID: <CAO6+pgJScW71-M3cZjLA6AYVAVgjEt488T9s+F-_0c7B+u-=pg@mail.gmail.com>

Packages supplied by your distribution can be trusted more than packages
from PyPi. Just my two cents.

Most distros offer nearly all the useful Python modules directly from the
repo.

Virtual environments are great, but if you want to add libraries to your
system interpreter I'd recommend a simple sync through your repo.

- Clint

On Fri, Jan 6, 2017 at 3:38 PM <cs at zip.com.au> wrote:

> On 06Jan2017 15:44, jim <jf_byrnes at comcast.net> wrote:
>
> >Setting up a new computer to run Ubuntu 16.04. Started using pip3 to
>
> >install all the python stuff I had on the old machine and got this
>
> >message:
>
> >
>
> >jfb at jims-1604:~$ sudo pip3 install matplotlib
>
> >[sudo] password for jfb:
>
> >The directory '/home/jfb/.cache/pip/http' or its parent directory is
>
> >not owned by the current user and the cache has been disabled. Please
>
> >check the permissions and owner of that directory. If executing pip
>
> >with sudo, you may want sudo's -H flag.
>
> >
>
> >I (jfb) own the directory in question.
>
> >
>
> >I used sudo because I recall needing to use it on the old machine to
>
> >get something to install. So is it necessary or even desirable to use sudo
>
> >with pip3?
>
>
>
> I would not, unless I were specificly trying to install into the system's
>
> python3 libraries. That will inherently fight with any vendor (Unbuntu)
>
> supplied packages that come through apt-get.
>
>
>
> Instead I would make myself a virtualenv _based off the system python3_
> and use
>
> the venv's pip to install extra packages. Not using sudo. They will land in
>
> your virtualenv directory's lib area, be entirely owned and controlled by
> you,
>
> and not have any complications that come with sudo.
>
>
>
> Then just symlink the virtualenv's "python3" into your own $HOME/bin and
>
> whenever you invoke "python3" it will run the virtualenv one, getting all
> the
>
> package goodness you have added.
>
>
>
> An important sysadmin rule of thumb: use apt (or yum etc, depending on
> distro)
>
> as root to install vendor supplied packages. And install your owon
> packages _as
>
> you_ in another area, _not_ in the system managed area. Virtualenv makes
> this
>
> very easy to do for Python.
>
>
>
> Cheers,
>
> Cameron Simpson <cs at zip.com.au>
>
> --
>
> https://mail.python.org/mailman/listinfo/python-list
>
>


From python at deborahswanson.net  Fri Jan  6 18:03:45 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Fri, 6 Jan 2017 15:03:45 -0800
Subject: Receiving a lot of double messages.
In-Reply-To: <o4p3p8$o5f$1@blaine.gmane.org>
Message-ID: <002701d26871$2222b9e0$27b23dae@sambora>

Grant Edwards wrote, on January 06, 2017 1:56 PM
> 
> On 2017-01-05, Antoon Pardon <antoon.pardon at rece.vub.ac.be> wrote:
> 
> > Is there something going on with the mailinglist? Because I have 
> > receive a lot
> > of double messages. One copy is fairly normal and is part 
> of the discussion 
> > thread, the other is completely seperated. -- Antoon Pardon.
> 
> Yep, there are a _lot_ of duplicate messages showing up on 
> gmane's NNTP server.  I would guess around 50-100 of them in 
> the past day. Entire chunks of long threads comprising 20-30 
> posts seem to be duplicated in some cases.  In other cases, 
> they're just individual posts that seem to be detached from 
> their original threads.
> 
> Something is seriously broken somewhere...
> 
> -- 
> Grant Edwards               grant.b.edwards        Yow! I 
> want a VEGETARIAN
>                                   at               BURRITO to 
> go ... with
>                               gmail.com            EXTRA MSG!!

162 duplicate messages, as of 2:04 PM PST today, to be precise. This
same thing happened when I was on the Exchange team at Microsoft, but
that was on a pre-release dogfood mail server, not even a beta for a
pre-release. Good thing it was only in-house Microsofties who had to
field the thousands of garbage messages when that happened.

The problem then was that they had to flush the mail queue that had
become clogged up with duplicate messages because some bit of code had
looped back on itself. 

Granted, the list mail server probably isn't an enterprise version, with
mail replicating between hundreds of servers, but as Chris mentioned, it
does take a feed from the newsgroup, and there's plenty of room for that
to break. Quite likely the fix for any mail server whose mail queue has
been corrupted is to flush it.



From valkrem at yahoo.com  Fri Jan  6 18:26:32 2017
From: valkrem at yahoo.com (Val Krem)
Date: Fri, 6 Jan 2017 23:26:32 +0000 (UTC)
Subject: crosstab output
References: <665870666.2223003.1483745192910.ref@mail.yahoo.com>
Message-ID: <665870666.2223003.1483745192910@mail.yahoo.com>

Hi all,

How do I access the rows and columns of a data frame crosstab output?


Here is code using  a sample data and output.

a= pd.read_csv("cross.dat", skipinitialspace=True)
xc=pd.crosstab(a['nam'],a['x1'],margins=True)

print(xc)

x1    0  1 
nam 
A1    3  2 
A2    1  4

I want to create a variable  by adding 2/(3+2) for the first row(A1)
and 4/(1+4) for the second row (A2)

Final data frame would be
A1 3 2  0.4
A2 1 4  0.8

Thank you in advance


From no.email at nospam.invalid  Fri Jan  6 20:34:09 2017
From: no.email at nospam.invalid (Paul Rubin)
Date: Fri, 06 Jan 2017 17:34:09 -0800
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
Message-ID: <87eg0f3b72.fsf@nightsong.com>

Peter Otten <__peter__ at web.de> writes:
> How would you implement stopmin()?

Use itertools.takewhile


From nimbiotics at gmail.com  Fri Jan  6 20:45:18 2017
From: nimbiotics at gmail.com (Mario R. Osorio)
Date: Fri, 6 Jan 2017 17:45:18 -0800 (PST)
Subject: The hardest problem in computer science...
In-Reply-To: <mailman.287.1483717046.2395.python-list@python.org>
References: <586f95ac$0$1589$c3e8da3$5496439d@news.astraweb.com>
 <586FB9C4.6000505@stoneleaf.us>
 <mailman.287.1483717046.2395.python-list@python.org>
Message-ID: <45df7e06-ca04-4aa3-90a0-32fa3f54d042@googlegroups.com>

On Friday, January 6, 2017 at 10:37:40 AM UTC-5, Ethan Furman wrote:
> On 01/06/2017 05:03 AM, Steve D'Aprano wrote:
> 
> > what do we call the vertical and horizontal line elements? I want to make
> > them configurable, which means the user has to be able to pass an argument
> > that specifies them. I have names for the individual components:
> >
> > XXX = namedtuple("XXX", "vline tee corner")
> >
> > default_YYY = XXX("?  ", "?? ", "?? ")
> > bold_YYY = XXX("?  ", "?? ", "?? ")
> > ascii_YYY = XXX("|  ", "|- ", "+- ")
> >
> > def draw_tree(tree, YYY=default_YYY):
> >      ...
> >
> > but what do I call XXX and YYY?
> 
> Looks like horizontal, vertical, and corner are as groups -- so I would call YYY "style" and XXX "default", "bold", and "ascii".
> 
> --
> ~Ethan~

back in the days of CPM this group was referred to as "box characters", and each of them were called as follows:

"?": vertical_line, v_line

"??": left_intersection, l_intersection, left_tee, l_tee

"??": bottom_left_corner, bl_corner

[...and son on...]

(the names also apply to the combination of lower ascii characters)




From nimbiotics at gmail.com  Fri Jan  6 20:49:12 2017
From: nimbiotics at gmail.com (Mario R. Osorio)
Date: Fri, 6 Jan 2017 17:49:12 -0800 (PST)
Subject: The hardest problem in computer science...
In-Reply-To: <45df7e06-ca04-4aa3-90a0-32fa3f54d042@googlegroups.com>
References: <586f95ac$0$1589$c3e8da3$5496439d@news.astraweb.com>
 <586FB9C4.6000505@stoneleaf.us>
 <mailman.287.1483717046.2395.python-list@python.org>
 <45df7e06-ca04-4aa3-90a0-32fa3f54d042@googlegroups.com>
Message-ID: <d7fc7ecf-0501-4ba0-80bd-1e56a5e64e3f@googlegroups.com>

On Friday, January 6, 2017 at 8:45:41 PM UTC-5, Mario R. Osorio wrote:
> On Friday, January 6, 2017 at 10:37:40 AM UTC-5, Ethan Furman wrote:
> > On 01/06/2017 05:03 AM, Steve D'Aprano wrote:
> > 
> > > what do we call the vertical and horizontal line elements? I want to make
> > > them configurable, which means the user has to be able to pass an argument
> > > that specifies them. I have names for the individual components:
> > >
> > > XXX = namedtuple("XXX", "vline tee corner")
> > >
> > > default_YYY = XXX("?  ", "?? ", "?? ")
> > > bold_YYY = XXX("?  ", "?? ", "?? ")
> > > ascii_YYY = XXX("|  ", "|- ", "+- ")
> > >
> > > def draw_tree(tree, YYY=default_YYY):
> > >      ...
> > >
> > > but what do I call XXX and YYY?
> > 
> > Looks like horizontal, vertical, and corner are as groups -- so I would call YYY "style" and XXX "default", "bold", and "ascii".
> > 
> > --
> > ~Ethan~
> 
> back in the days of CPM this group was referred to as "box characters", and each of them were called as follows:
> 
> "?": vertical_line, v_line
> 
> "??": left_intersection, l_intersection, left_tee, l_tee
> 
> "??": bottom_left_corner, bl_corner
> 
> [...and son on...]
> 
> (the names also apply to the combination of lower ascii characters)



NOW ... in particular this case I'd call them:

"?": vertical_line, v_line
 
"??": node
 
"??": last_node, l_node



From cs at zip.com.au  Fri Jan  6 21:24:24 2017
From: cs at zip.com.au (Cameron Simpson)
Date: Sat, 7 Jan 2017 13:24:24 +1100
Subject: Using sudo with pip3?
In-Reply-To: <CAO6+pgJScW71-M3cZjLA6AYVAVgjEt488T9s+F-_0c7B+u-=pg@mail.gmail.com>
References: <CAO6+pgJScW71-M3cZjLA6AYVAVgjEt488T9s+F-_0c7B+u-=pg@mail.gmail.com>
Message-ID: <20170107022424.GA68905@cskk.homeip.net>

On 06Jan2017 23:03, Clint Moyer <contact at clintmoyer.com> wrote:
>Packages supplied by your distribution can be trusted more than packages
>from PyPi. Just my two cents.
>Most distros offer nearly all the useful Python modules directly from the
>repo.

I would agree with this on the whole. And also that it is generally better to 
add modules to your system python via the distro's repo because that bring 
benefit to every user on the system, not just yourself.

>Virtual environments are great, but if you want to add libraries to your
>system interpreter I'd recommend a simple sync through your repo.

I'm directly advocating _not_ adding PyPI packages to the system interpreter.  
If nothing else, they may differ in behaviour and potentially actually break 
system behaviour.

Having your on virtualenv is good for: adding packages no provided by your 
vendor, adding packages deliberately different from those from your vendor (eg 
newer versions with specific bugfixes or extra features), having an isolated 
environment for packages (you can make more than one virtual environment).

And of course it avoids interfering with your system python install.

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


From orgnut at yahoo.com  Fri Jan  6 22:12:52 2017
From: orgnut at yahoo.com (Larry Hudson)
Date: Fri, 6 Jan 2017 19:12:52 -0800
Subject: The hardest problem in computer science...
In-Reply-To: <586f95ac$0$1589$c3e8da3$5496439d@news.astraweb.com>
References: <586f95ac$0$1589$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <45udnZ3EUtsowe3FnZ2dnUU7-VnNnZ2d@giganews.com>

On 01/06/2017 05:03 AM, Steve D'Aprano wrote:
> The second hardest problem in computer science is cache invalidation.
>
> The *hardest* problem is naming things.
>
> In a hierarchical tree view widget that displays items like this:
>
>
>     Fiction
>     ?? Fantasy
>     ?  ?? Terry Pratchett
>     ?  ?  ?? Discworld
[snip]

> but what do I call XXX and YYY?
>
>
> Seriously-considering-just-hard-coding-them-as-magic-constants-ly y'rs,

I don't know if this is helpful or even relevant, but here is a class for using these 
box-drawing characters that I wrote for my own use.  (I'm just a hobby programmer...)
It's not very elegant and not particularly convenient to use, but it is usable.  And I hesitate 
to post it because it is so long (approx 90 line docstring to explain its use, and ending with 
some test code).  In any case, here it is...

<code>
#   boxch.py

"""
BoxChr class to handle box-drawing characters.

The character is selected by a two-character string:
     'tl', 'tm', 'tr' -- Top Left, Top Mid, Top Right:  ? ? ?
     'ml', 'mm', 'mr' -- Mid Left, Mid Mid, Mid Right:  ? ? ?
     'bl', 'bm', 'br' -- Bot Left, Bot Mid, Bot Right:  ? ? ?
     'hz', 'vt'       -- Horizontal and Vertical lines: ? ?
     Case is ignored.  Invalid selection string returns a dot:  '?'
     NOTE:  It is currently disabled, but the code is still
         available to handle small and large dots with 'dt' and 'dd'.
         These both ignore the style.

The style is selected by a two-character string:
     The characters are 's', 'd' and 'b' for single, double and bold.
     The first character defines the horizontal components,
         the second defines the vertical components.
     The valid styles are 'ss', 'sd', 'sb', 'ds', 'dd', 'bs', 'bb'.
     The potential styles 'db' and 'bd' are invalid.
     The class defaults to 'ss' -- single horizontal, single vertical.
     Case is ignored.  Invalid style string raises ValueError.

NOTE:  The following examples assume bc has been set to a BoxChr class.
     bc = BoxChr()       #   Style defaults to 'ss'
       or
     bc = BoxChr('sd')   #   Style set to single/double, or whatever desired.
     (Examples assume 'ss' style.)

Attributes:
     style:  set or return the style-code string.
             Case is ignored.  Invalid style raises ValueError.
         Examples:  bc.style = 'ds' -- sets style to double/single.
             st = bc.style -- sets variable st to current style code.

Methods:
     [] (__getitem__):  Returns selected box character.
             Case is ignored.  Invalid selector returns a dot:  '?'
         Example:  bc['tm'] returns '?'

     bxstr():   Returns a string created from a sequence of box character codes
             and 'normal' characters.  (in this description 'selector' refers
             to the two-character codes as defined above.)

             Each element of the given sequence (list or tuple) must be a
             string, either a series of selector codes, or a 'normal' string
             (one without any box selectors).  The box character selector string
             must start with 'BX' followed by the selector codes, separated by
             spaces.  The 'BX' must be upper case, but the case of the selector
             codes is ignored.  A space between the 'BX' prefix and the first
             selector code is optional.  This selector string can only contain
             selector codes.  'Normal' characters are simply given as normal
             strings, interspersed with the selector strings in the given
             sequence.

             If the selection is only box characters, it can opionally be passed
             as a single string rather than enclosing it in a list.
         Example:
             seq = ['BX ml hz', ' TEXT ', 'BX hz mr']
             bc.bxstr(seq) returns '?? TEXT ??'
         Note:
             If you need a string beginning with 'BX' it has to be given
             as a single-character string 'B' followed by a string containing
             the remaining text.  Example 'BX etc' must be given as:
             ['B', 'X etc'].

     boxtext():  Create boxed text, returned as a single string with
             embedded newlines.

         Parameters:
             txt     The text to use
             tsize   Expand tabs to specified number of spaces,  Default is 4
             just    '<', '^' or '>' as left/center/right justification.
                     Default is '<' ? left-justified.
             tall    If True, inserts a blank line above and below the text.
                     If False, no extra blank lines are used.
                     Default is True.

             Text can be either a single string with embedded newlines (ie. a
             triple-quoted string) or list of strings.  Trailing blank lines
             are removed.  Center and right justification will strip whitespace
             from both ends of the lines.  Left justification (the default)
             only strips trailing whitespace.

             Width is based on the length of the longest line, plus two spaces
             before and after.
"""

class BoxChr:
     def __init__(self, style='ss'):
         self._styles = ('ss', 'sd', 'sb', 'ds', 'dd', 'bs', 'bb')
         self._keys = ('tl', 'tm', 'tr', 'ml', 'mm', 'mr',
                 'bl', 'bm', 'br', 'hz', 'vt')       #   'dt', 'dd')
         self._boxchrs = {
             'tl' : ('?', '?', '?', '?', '?', '?', '?'),
             'tm' : ('?', '?', '?', '?', '?', '?', '?'),
             'tr' : ('?', '?', '?', '?', '?', '?', '?'),
             'ml' : ('?', '?', '?', '?', '?', '?', '?'),
             'mm' : ('?', '?', '?', '?', '?', '?', '?'),
             'mr' : ('?', '?', '?', '?', '?', '?', '?'),
             'bl' : ('?', '?', '?', '?', '?', '?', '?'),
             'bm' : ('?', '?', '?', '?', '?', '?', '?'),
             'br' : ('?', '?', '?', '?', '?', '?', '?'),
             'hz' : ('?', '?', '?', '?', '?', '?', '?'),
             'vt' : ('?', '?', '?', '?', '?', '?', '?')
#           'dt' : ('?', '?', '?', '?', '?', '?', '?'),
#           'dd' : ('?', '?', '?', '?', '?', '?', '?')
         }
         self._setStyle(style)

     def _setStyle(self, style):
         """Set the class style"""
         try:
             self._style = self._styles.index(style.lower())
         except IndexError:
             raise ValueError


     def _getStyle(self):
         """Return the class style code"""
         return self._styles[self._style]

     style = property(_getStyle, _setStyle)

     def __getitem__(self, key):
         """Select and return the box character"""
         try:
             return self._boxchrs[key.lower()][self._style]
         except KeyError:
             return '?'

     def bxstr(self, slst):
         """Create a string from a given sequence of strings"""
         def cnvst(s):
             """Convert selector string to box character string"""
             bs = []
             for sc in s:                #   For each selector code
                 bs.append(self.__getitem__(sc)) #   Get box char
             return ''.join(bs)

         out = []
         if isinstance(slst, str):       #   Input is string?
             slst = [slst]               #   Make it a list
         for ss in slst:                 #   For each string in list
             if ss.startswith('BX'):     #   Check if selector or normal string
                 out.append(cnvst(ss[2:].split()))   #   Selector
             else:
                 out.append(ss)          #   Normal string
         return ''.join(out)

     def boxtext(self, txt, tsize=4, just='<', tall=True):
         """Create boxed text"""
         if just not in '<^>':           #   Check for valid justification code
             just = '<'
         if isinstance(txt, str):        #   Check for string input
             txt = txt.split('\n')       #   Convert to list
         while txt[-1].rstrip() == '':   #   Delete trailing blank lines
             txt = txt[:-1]
         if just == '<':                 #   Left just, only strip on right
             txt = [line.rstrip() for line in txt]
         else:                           #   Otherwise strip both ends
             txt = [line.strip() for line in txt]
         txt = [line.expandtabs(tsize) for line in txt]  #   Cnvt tabs to spaces
         maxlen = max([len(line) for line in txt]) + 4   #   Find longest line

         #   Create the boxed text
         out = []
         out.append(self.bxstr('BXtl ' + 'hz ' * maxlen + 'tr'))
         if tall:
             out.append(self.bxstr(['BXvt', ' ' * maxlen, 'BXvt']))
         for line in txt:
             out.append(self.bxstr(['BXvt', '  {:{}{}}  '.
                     format(line, just, maxlen-4), 'BXvt']))
         if tall:
             out.append(self.bxstr(['BXvt', ' ' * maxlen, 'BXvt']))
         out.append(self.bxstr('BXbl ' + 'hz ' * maxlen + 'br'))
         return '\n'.join(out)

#======================================
if __name__ == '__main__':
     def grid(bc):
         """Print a box"""
         print(bc.bxstr(['BXtl hz hz hz TM hz Hz hZ tr']))
         print(bc.bxstr(['BXvt', '   ', 'BXvt', '   ', 'BXvt']))
         print(bc.bxstr('BX ml hz hz hz mm hz hz hz mr'))
         print(bc.bxstr(['BX vt', '   ', 'BXvt', '   ', 'BXvt']))
         print(bc.bxstr('BXbl hz hz hz bm hz hz hz br'))

     bc = BoxChr()
     #   Check all chars in all styles
     for style in bc._styles:
         bc.style = style
         grid(bc)

     #   Verify error test
     try:
         bc.style = 'xx'
     except ValueError:
         print('Invaled style')

     #   Test boxtext() method
     jab = """'Twas brillig, and the slithy toves
\tDid gyre and gimbol in the wabe.
All mimsy were the borogoves,
\tAnd the momraths outgrabe.
     """
     bc.style='ds'
     print(bc.boxtext(jab))
     print(bc.boxtext(jab, tsize=8))
     print(bc.boxtext(jab, just='^'))
     print(bc.boxtext(jab, just='>'))
     print(bc.boxtext(jab, tall=False))

</code>

-- 
      -=- Larry -=-


From python at deborahswanson.net  Fri Jan  6 22:46:50 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Fri, 6 Jan 2017 19:46:50 -0800
Subject: Namedtuples: TypeError: 'str' object is not callable
Message-ID: <005301d26898$ae2bcef0$27b23dae@sambora>

I'm not sure what Python is complaining about here, or why.
 
Here's the example from the Python docs: 
https://docs.python.org/3/library/collections.html#collections.namedtupl
e

EmployeeRecord = namedtuple('EmployeeRecord', 'name, age, title,
department, paygrade')

import csv
for emp in map(EmployeeRecord._make, csv.reader(open("employees.csv",
"rb"))):
    print(emp.name, emp.title)

And here's my code:

listings = namedtuple('listings', ['CLDesc', 'url', 'desc',
'Description', 	'Location', 'STco', 'miles', 'Kind', 'Rent', 'Date',
'br', 'Notes', 
	'yesno', 'mark', 'arc'])
for lst in map(listings._make, csv.reader(open('Moving 2017.csv',
"r"))):
	.
	.

(['x', 'y'] is a valid format for the field names, and there are no
errors when the definition for listings executes.)


And here's the Traceback in PyCharm:
  File "E:/Coding projects/Pycharm/Moving/moving_numberedtuples.py",
line 139, in moving()
    for lst in map(listings._make, csv.reader(open('E:\\Coding
projects\\Pycharm\\Moving\\Moving 2017 in.csv',"r"))):
TypeError: 'str' object is not callable

What str object is not callable, and how do I fix it?  I see an
iteration variable (lst), a namedtuples method call(listings._make,
which makes a new instance of listings) and a csv.reader call, a
variable and 2 method calls, none of which are bare strings, except
possibly 'listings._make', but there's no str it might be trying to call
that I can see. My 'for' statement looks like a good copy of the example
from the docs to me, and the example in the docs uses
'EmployeeRecord._make' with no parentheses.

Is the example from the docs possibly in error? I don't see any other
possibility, but maybe I'm not looking in the right place. 

I don't know enough about classes in Python yet to know if this is ok or
not. And when I tried again with 'listings._make()', I got:

TypeError: _make() missing 1 required positional argument: 'iterable'.

This suggests that maybe 'listings._make' is wrong, but if it should be
'listings._make()', what should the iterable be? 'listings'?

'listings._make(listings)' looks awfully redundant for Python, so 
'_make(listings)' would make more sense (pun not intended), and seems to
be what the error thinks it is. But when I change it to
'_make(listings)', I get:

NameError: name '_make' is not defined

'listings._make(listings)' gets "TypeError: 'type' object is not
iterable", which answers the question of whether a namedtuple instance
(if that's what 'listings' is) is an iterable. It isn't.

There might be a version problem here. I'm using Python 3.4.3, and the
url for this page simply indicates version 3. As most of us know,
there's a lot of variance between dot versions of 3, and quite possibly
not all of the changes are documented correctly. In 3.4.3 the usage
might be slightly different, or the code broken.

Any help with this would be hugely appreciated.




From rosuav at gmail.com  Fri Jan  6 23:04:42 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 7 Jan 2017 15:04:42 +1100
Subject: Namedtuples: TypeError: 'str' object is not callable
In-Reply-To: <005301d26898$ae2bcef0$27b23dae@sambora>
References: <005301d26898$ae2bcef0$27b23dae@sambora>
Message-ID: <CAPTjJmqwhWgzyfmBUF1KUzvTfV6R1adcdxhLOg3XrXxSGD5bCQ@mail.gmail.com>

On Sat, Jan 7, 2017 at 2:46 PM, Deborah Swanson
<python at deborahswanson.net> wrote:
> And here's the Traceback in PyCharm:
>   File "E:/Coding projects/Pycharm/Moving/moving_numberedtuples.py",
> line 139, in moving()
>     for lst in map(listings._make, csv.reader(open('E:\\Coding
> projects\\Pycharm\\Moving\\Moving 2017 in.csv',"r"))):
> TypeError: 'str' object is not callable
>
> What str object is not callable, and how do I fix it?

Toss in a 'print' above that. You're calling map and open (and
csv.reader, but I doubt you've shadowed that). My money would be on
'map' having been assigned something.

ChrisA


From python at deborahswanson.net  Sat Jan  7 00:07:13 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Fri, 6 Jan 2017 21:07:13 -0800
Subject: Namedtuples: TypeError: 'str' object is not callable
In-Reply-To: <CAPTjJmqwhWgzyfmBUF1KUzvTfV6R1adcdxhLOg3XrXxSGD5bCQ@mail.gmail.com>
Message-ID: <005e01d268a3$e8e73470$27b23dae@sambora>

Chris Angelico wrote, on January 06, 2017 8:05 PM
> To: python-list at python.org
> Subject: Re: Namedtuples: TypeError: 'str' object is not callable
> 
> 
> On Sat, Jan 7, 2017 at 2:46 PM, Deborah Swanson 
> <python at deborahswanson.net> wrote:
> > And here's the Traceback in PyCharm:
> >   File "E:/Coding projects/Pycharm/Moving/moving_numberedtuples.py",
> > line 139, in moving()
> >     for lst in map(listings._make, csv.reader(open('E:\\Coding 
> > projects\\Pycharm\\Moving\\Moving 2017 in.csv',"r"))):
> > TypeError: 'str' object is not callable
> >
> > What str object is not callable, and how do I fix it?
> 
> Toss in a 'print' above that. You're calling map and open 
> (and csv.reader, but I doubt you've shadowed that). My money 
> would be on 'map' having been assigned something.
> 
> ChrisA

And you would be precisely correct. I have a variable named 'map', and I
intended to delete it and the code that used it, but totally forgot
about it. It's still in there somewhere, but a simple search will find
it.

I really don't know how long it would've taken me to think of that, so
thank you!

Deborah



From rosuav at gmail.com  Sat Jan  7 00:14:27 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 7 Jan 2017 16:14:27 +1100
Subject: Namedtuples: TypeError: 'str' object is not callable
In-Reply-To: <005e01d268a3$e8e73470$27b23dae@sambora>
References: <CAPTjJmqwhWgzyfmBUF1KUzvTfV6R1adcdxhLOg3XrXxSGD5bCQ@mail.gmail.com>
 <005e01d268a3$e8e73470$27b23dae@sambora>
Message-ID: <CAPTjJmquhv0VzRHipvgbk+wWu0=jg_fhNG0FmdH=sY2WdNrVhA@mail.gmail.com>

On Sat, Jan 7, 2017 at 4:07 PM, Deborah Swanson
<python at deborahswanson.net> wrote:
> And you would be precisely correct. I have a variable named 'map', and I
> intended to delete it and the code that used it, but totally forgot
> about it. It's still in there somewhere, but a simple search will find
> it.
>
> I really don't know how long it would've taken me to think of that, so
> thank you!

I have a well-trained crystal ball :)

ChrisA


From python at deborahswanson.net  Sat Jan  7 01:11:26 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Fri, 6 Jan 2017 22:11:26 -0800
Subject: Namedtuples: TypeError: 'str' object is not callable
In-Reply-To: <CAPTjJmquhv0VzRHipvgbk+wWu0=jg_fhNG0FmdH=sY2WdNrVhA@mail.gmail.com>
Message-ID: <000001d268ac$e14b0760$27b23dae@sambora>

Chris Angelico wrote, on January 06, 2017 9:14 PM
> 
> On Sat, Jan 7, 2017 at 4:07 PM, Deborah Swanson 
> <python at deborahswanson.net> wrote:
> >
> > I really don't know how long it would've taken me to think of that,
so 
> > thank you!
> 
> I have a well-trained crystal ball :)
> 
> ChrisA

More like a very experienced eye. I keep hoping I'll get one of those,
but it takes time.



From jussi.piitulainen at helsinki.fi  Sat Jan  7 01:55:54 2017
From: jussi.piitulainen at helsinki.fi (Jussi Piitulainen)
Date: Sat, 07 Jan 2017 08:55:54 +0200
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com>
Message-ID: <lf5h95bs6it.fsf@ling.helsinki.fi>

Paul Rubin writes:

> Peter Otten writes:
>> How would you implement stopmin()?
>
> Use itertools.takewhile

How? It consumes the crucial stop element:

   it = iter('what?')
   list(takewhile(str.isalpha, it)) # ==> ['w', 'h', 'a', 't']
   next(it, 42) # ==> 42


From rustompmody at gmail.com  Sat Jan  7 02:10:11 2017
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 6 Jan 2017 23:10:11 -0800 (PST)
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
In-Reply-To: <lf5h95bs6it.fsf@ling.helsinki.fi>
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com> <lf5h95bs6it.fsf@ling.helsinki.fi>
Message-ID: <029aea48-3f1f-4a99-8a3b-6e8a906cbdfd@googlegroups.com>

On Saturday, January 7, 2017 at 12:26:04 PM UTC+5:30, Jussi Piitulainen wrote:
> Paul Rubin writes:
> 
> > Peter Otten writes:
> >> How would you implement stopmin()?
> >
> > Use itertools.takewhile
> 
> How? It consumes the crucial stop element:
> 
>    it = iter('what?')
>    list(takewhile(str.isalpha, it)) # ==> ['w', 'h', 'a', 't']
>    next(it, 42) # ==> 42

I was also wondering how?
In a lazy language (eg haskell) with non-strict foldr (reduce but rightwards)
supplied non-strict operator this is trivial.
ie in python idiom with reduce being right_reduce
reduce(operator.mul, [1,2,0,4,...], 1)
the reduction would stop at the 0
Not sure how to simulate this in a strict language like python
Making fold(r) non-strict by using generators is ok
How to pass a non-strict operator?


From steve+python at pearwood.info  Sat Jan  7 02:34:16 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Sat, 07 Jan 2017 18:34:16 +1100
Subject: The hardest problem in computer science...
References: <586f95ac$0$1589$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <587099fa$0$1610$c3e8da3$5496439d@news.astraweb.com>

On Sat, 7 Jan 2017 12:03 am, Steve D'Aprano wrote:

> The second hardest problem in computer science is cache invalidation.
> 
> The *hardest* problem is naming things.

Thanks everyone who answered, but I think some of you misunderstood my
question. I know that the individual characters themselves are called some
variation of "line drawing characters", or "box drawing characters". But
the important part of the question was given by the Python code:

> XXX = namedtuple("XXX", "vline tee corner")
> 
> default_YYY = XXX("?  ", "?? ", "?? ")
> bold_YYY = XXX("?  ", "?? ", "?? ")
> ascii_YYY = XXX("|  ", "|- ", "+- ")
> 
> def draw_tree(tree, YYY=default_YYY):
>     ...
> 
> 
> but what do I call XXX and YYY?

After puzzling over this for three days, it suddenly hit me:

Theme = namedtuple("Theme", "vline tee corner")

DEFAULT = Theme("?  ", "?? ", "?? ")
BOLD = Theme("?  ", "?? ", "?? ")
ASCII = Theme("|  ", "|- ", "+- ")
 
def draw_tree(tree, theme=DEFAULT):
    ...



Ethan's idea of "style" is also good.


Thanks for all your ideas!



-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From steve+python at pearwood.info  Sat Jan  7 03:01:27 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Sat, 07 Jan 2017 19:01:27 +1100
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
Message-ID: <5870a057$0$1585$c3e8da3$5496439d@news.astraweb.com>

On Sat, 7 Jan 2017 01:04 am, Peter Otten wrote:

> Example: you are looking for the minimum absolute value in a series of
> integers. As soon as you encounter the first 0 it's unnecessary extra work
> to check the remaining values, but the builtin min() will continue.
> 
> The solution is a minimum function that allows the user to specify a stop
> value:
> 
>>>> from itertools import count, chain
>>>> stopmin(chain(reversed(range(10)), count()), key=abs, stop=0)
> 0
> 
> How would you implement stopmin()?

That depends on whether you want to stop when you find a value *equal* to
the stop value, or *less than* the stop value, or both.

It depends on whether you want to check for equality or check for any
arbitrary condition.

It depends on whether you want the stop value to be included or not. (It
looks like you do want it included.)

But I'd start with this:


# not tested
def stopmin(iterable, key=None, stop=None):
    it = iter(iterable)
    try:
        smallest = next(it)
    except StopIteration:
        raise ValueError('empty iterable has no minimum')
    else:
        if key is not None:
            keyed_smallest = key(smallest)
    if key is None:
        for x in iterable:
            if x < smallest:
                smallest = x
            if x == stop:
                break
    else:
        for x in iterable:
            y = key(x)
            if y < keyed_smallest:
                keyed_smallest = y
                smallest = x
            if y == stop:
                break
    return smallest


Another possibility is to create a variant of itertools takewhile:

def takeuntil(predicate, iterable):
    # takeuntil(lambda x: x<5, [1,4,6,4,1]) --> 1 4 6
    for x in iterable:
        yield x
        if predicate(x):
            break

min(takeuntil(lambda x: x == 0, iterable), key=abs)


py> from itertools import count, chain
py> iterable = chain(reversed(range(10)), count())
py> min(takeuntil(lambda x: x == 0, iterable), key=abs)
0
py> iterable = chain(range(-9, 10), count())
py> min(takeuntil(lambda x: x == 0, iterable), key=abs)
0




-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From jussi.piitulainen at helsinki.fi  Sat Jan  7 03:12:38 2017
From: jussi.piitulainen at helsinki.fi (Jussi Piitulainen)
Date: Sat, 07 Jan 2017 10:12:38 +0200
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com> <lf5h95bs6it.fsf@ling.helsinki.fi>
 <029aea48-3f1f-4a99-8a3b-6e8a906cbdfd@googlegroups.com>
Message-ID: <lf5d1fzs2yx.fsf@ling.helsinki.fi>

Rustom Mody writes:

> On Saturday, Jussi Piitulainen wrote:
>> Paul Rubin writes:
>> 
>> > Peter Otten writes:
>> >> How would you implement stopmin()?
>> >
>> > Use itertools.takewhile
>> 
>> How? It consumes the crucial stop element:
>> 
>>    it = iter('what?')
>>    list(takewhile(str.isalpha, it)) # ==> ['w', 'h', 'a', 't']
>>    next(it, 42) # ==> 42
>
> I was also wondering how?
> In a lazy language (eg haskell) with non-strict foldr (reduce but
> rightwards) supplied non-strict operator this is trivial.
> ie in python idiom with reduce being right_reduce
> reduce(operator.mul, [1,2,0,4,...], 1)
> the reduction would stop at the 0
> Not sure how to simulate this in a strict language like python
> Making fold(r) non-strict by using generators is ok
> How to pass a non-strict operator?

I think it would have to be some really awkward pseudo-operator that
throws an exception when it encounters its zero, and then reduce (or
something outside reduce) would catch that exception. Something like
that could be done but it would still be awkward. Don't wanna :)

You switched to a simpler operator. Would Haskell notice that

   def minabs(x, y): return min(x, y, key = abs)

has a meaningful zero? Surely it has its limits somewhere and then the
programmer needs to supply the information.


From rosuav at gmail.com  Sat Jan  7 03:19:03 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 7 Jan 2017 19:19:03 +1100
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
In-Reply-To: <lf5d1fzs2yx.fsf@ling.helsinki.fi>
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com> <lf5h95bs6it.fsf@ling.helsinki.fi>
 <029aea48-3f1f-4a99-8a3b-6e8a906cbdfd@googlegroups.com>
 <lf5d1fzs2yx.fsf@ling.helsinki.fi>
Message-ID: <CAPTjJmq46BbOMYNCfvthCoAbz3+Lyf0GR9WhENLEGAhVqi+YgA@mail.gmail.com>

On Sat, Jan 7, 2017 at 7:12 PM, Jussi Piitulainen
<jussi.piitulainen at helsinki.fi> wrote:
> You switched to a simpler operator. Would Haskell notice that
>
>    def minabs(x, y): return min(x, y, key = abs)
>
> has a meaningful zero? Surely it has its limits somewhere and then the
> programmer needs to supply the information.

If the return value of abs is int(0..) then yeah, it could. (Or
whatever the notation is. That's Pike's limited-range-int type
syntax.)

ChrisA


From jussi.piitulainen at helsinki.fi  Sat Jan  7 03:54:35 2017
From: jussi.piitulainen at helsinki.fi (Jussi Piitulainen)
Date: Sat, 07 Jan 2017 10:54:35 +0200
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com> <lf5h95bs6it.fsf@ling.helsinki.fi>
 <029aea48-3f1f-4a99-8a3b-6e8a906cbdfd@googlegroups.com>
 <lf5d1fzs2yx.fsf@ling.helsinki.fi>
 <CAPTjJmq46BbOMYNCfvthCoAbz3+Lyf0GR9WhENLEGAhVqi+YgA@mail.gmail.com>
 <mailman.306.1483777152.2395.python-list@python.org>
Message-ID: <lf58tqns110.fsf@ling.helsinki.fi>

Chris Angelico writes:

> On Sat, Jan 7, 2017 at 7:12 PM, Jussi Piitulainen wrote:

>> You switched to a simpler operator. Would Haskell notice that
>>
>>    def minabs(x, y): return min(x, y, key = abs)
>>
>> has a meaningful zero? Surely it has its limits somewhere and then
>> the programmer needs to supply the information.
>
> If the return value of abs is int(0..) then yeah, it could. (Or
> whatever the notation is. That's Pike's limited-range-int type
> syntax.)

Maybe so. If Haskell abs has such types. (For integers, rationals,
whatever numeric types Haskell has, which I've quite forgotten, or it
may have even changed since I knew some Haskell. It's been a while.)

I rewrite the question so that the answer cannot be deduced from just
the types of the functions:

    def minabs(x, y): return min(x, y, key = lambda w: max(w, -w))

Surely max of two ints is an int. Maybe the Haskell compiler could
specialize the type, but my question is, is it _guaranteed_ to do so,
and how should the programmer know to rely on that?


From greg.ewing at canterbury.ac.nz  Sat Jan  7 04:12:49 2017
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sat, 07 Jan 2017 22:12:49 +1300
Subject: Namedtuples: TypeError: 'str' object is not callable
In-Reply-To: <mailman.301.1483760810.2395.python-list@python.org>
References: <005301d26898$ae2bcef0$27b23dae@sambora>
 <mailman.301.1483760810.2395.python-list@python.org>
Message-ID: <edbpojFj93tU1@mid.individual.net>

Deborah Swanson wrote:
>   File "E:/Coding projects/Pycharm/Moving/moving_numberedtuples.py",
> line 139, in moving()
>     for lst in map(listings._make, csv.reader(open('E:\\Coding
> projects\\Pycharm\\Moving\\Moving 2017 in.csv',"r"))):
> TypeError: 'str' object is not callable

I know you've found the answer to this one, but as a general
tip, if you're getting an exception from a complicated line like
that, it can pay to break it down into simpler steps, then you
can see more clearly at what stage of the process the exception
is occurring. E.g.

   file = open('E:\\Coding projects\\Pycharm\\Moving\\Moving 2017 in.csv',"r")
   reader = csv.reader(file)
   rows = map(listings._make, reader)
   for lst in rows:
     ...

In this case the traceback would have pointed you to the third
line, telling you that it was something to do with the map()
call.

-- 
Greg


From motoom at xs4all.nl  Sat Jan  7 04:32:44 2017
From: motoom at xs4all.nl (Michiel Overtoom)
Date: Sat, 7 Jan 2017 10:32:44 +0100
Subject: Using sudo with pip3?
In-Reply-To: <20170107022424.GA68905@cskk.homeip.net>
References: <CAO6+pgJScW71-M3cZjLA6AYVAVgjEt488T9s+F-_0c7B+u-=pg@mail.gmail.com>
 <20170107022424.GA68905@cskk.homeip.net>
Message-ID: <2BFDB1B8-E168-4D10-BEF8-845D3FC9BA69@xs4all.nl>


> On 2017-01-07, at 03:24, Cameron Simpson <cs at zip.com.au> wrote:
> 
> Having your on virtualenv is good for: [...] having an isolated environment for packages (you can make more than one virtual environment).

Yes, indeed. For example, if you have to maintain two different codebases, one using Django 1.8 and the other Django 1.10 and a slew of other packages, for example an older and newer version of allauth, you'd have to create two virtual environments or otherwise you'll end up with a broken situation.

Greetings,

From python at deborahswanson.net  Sat Jan  7 04:41:56 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sat, 7 Jan 2017 01:41:56 -0800
Subject: Namedtuples: TypeError: 'str' object is not callable
In-Reply-To: <edbpojFj93tU1@mid.individual.net>
Message-ID: <001301d268ca$497d8110$27b23dae@sambora>

Gregory Ewing wrote, on January 07, 2017 1:13 AM
> 
> Deborah Swanson wrote:
> >   File "E:/Coding projects/Pycharm/Moving/moving_numberedtuples.py",
> > line 139, in moving()
> >     for lst in map(listings._make, csv.reader(open('E:\\Coding 
> > projects\\Pycharm\\Moving\\Moving 2017 in.csv',"r"))):
> > TypeError: 'str' object is not callable
> 
> I know you've found the answer to this one, but as a general 
> tip, if you're getting an exception from a complicated line 
> like that, it can pay to break it down into simpler steps, 
> then you can see more clearly at what stage of the process 
> the exception is occurring. E.g.
> 
>    file = open('E:\\Coding projects\\Pycharm\\Moving\\Moving 
> 2017 in.csv',"r")
>    reader = csv.reader(file)
>    rows = map(listings._make, reader)
>    for lst in rows:
>      ...
> 
> In this case the traceback would have pointed you to the 
> third line, telling you that it was something to do with the 
> map() call.
> 
> -- 
> Greg

Thanks Greg. I'm really kicking myself for seeing everything in that
statement except the 'map('! Not really sure why it was invisible to me,
but the mind is very devious (also a Terrible Thing to Taste, according
to Ministry).

But your method gives a systematic way to break things down and look at
them one by one. It can be really dismaying to have a complex statement
like this one, that you copied from an example, and have it spit out
error after error no matter what you try.  Having a systematic method of
approach is quite probably guaranteed to succeed.

(I'll bet you can guess why I'm taking on numberedtuples. Hope to have
the rewritten code using them soon, and the more I look at it the surer
I am that numberedtuples will clean up a lot of fuzziness and wobbly
code. Thanks for the suggestion.) 

Deborah



From steve+python at pearwood.info  Sat Jan  7 05:56:18 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Sat, 07 Jan 2017 21:56:18 +1100
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <072dfa54-0e8f-ee1e-b822-ad96300a1e6b@biologie.uni-freiburg.de>
 <mailman.290.1483733240.2395.python-list@python.org>
Message-ID: <5870c953$0$1614$c3e8da3$5496439d@news.astraweb.com>

On Sat, 7 Jan 2017 07:06 am, Wolfgang Maier wrote:

> On 1/6/2017 15:04, Peter Otten wrote:
[...]
>> How would you implement stopmin()?
>>
> 
> How about:
> 
> def stopmin (iterable, key, stop):
>      def take_until ():
>          for e in iterable:
>              yield e
>              if key(e) <= stop:
>                  break
>      return min(take_until(), key=key)

Heh, great minds think alike :-)




-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From __peter__ at web.de  Sat Jan  7 06:42:58 2017
From: __peter__ at web.de (Peter Otten)
Date: Sat, 07 Jan 2017 12:42:58 +0100
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <lf57f68805f.fsf@ling.helsinki.fi>
Message-ID: <o4qk7v$vdu$1@blaine.gmane.org>

Jussi Piitulainen wrote:

> Peter Otten writes:
> 
>> Example: you are looking for the minimum absolute value in a series of
>> integers. As soon as you encounter the first 0 it's unnecessary extra
>> work to check the remaining values, but the builtin min() will continue.
>>
>> The solution is a minimum function that allows the user to specify a stop
>> value:
>>
>>>>> from itertools import count, chain
>>>>> stopmin(chain(reversed(range(10)), count()), key=abs, stop=0)
>> 0
>>
>> How would you implement stopmin()?
> 
> Only let min see the data up to, but including, the stop value:

I should have mentioned that my actual use case has a costly key() function.

> from itertools import groupby
> 
> def takeuntil(data, pred):
>     '''Take values from data until and including the first that
>     satisfies pred (until data is exhausted if none does).'''
>     for kind, group in groupby(data, pred):
>         if kind:
>             yield next(group)
>             break
>         else:
>             yield from group

A clever takeuntil() implementation ;) I may steal it for my current 
favourite

def stopmin_du(items, *, key, stop):
    # decorate, process, undecorate
    pairs = ((key(item), item) for item in items)
    pairs = takeuntil(pairs, lambda pair: pair[0] <= stop)
    return min(pairs, key=firstitem)[1]


> def stopmin(data, key, stop):
>     return min(takeuntil(data, lambda o : key(o) == stop),
>                key = key)
> 
> data = '31415926'
> for stop in range(5):
>     print(stop,
>           '=>', repr(''.join(takeuntil(data, lambda o : int(o) == stop))),
>           '=>', repr(stopmin(data, int, stop)))
> 
> # 0 => '31415926' => '1'
> # 1 => '31' => '1'
> # 2 => '3141592' => '1'
> # 3 => '3' => '3'
> # 4 => '314' => '1'
> 
> from itertools import count, chain
> print(stopmin(chain(reversed(range(10)), count()), key=abs, stop=0))
> print(stopmin(chain(reversed(range(10)), count()), key=abs, stop=3))
> 
> # 0
> # 3




From __peter__ at web.de  Sat Jan  7 06:44:05 2017
From: __peter__ at web.de (Peter Otten)
Date: Sat, 07 Jan 2017 12:44:05 +0100
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <072dfa54-0e8f-ee1e-b822-ad96300a1e6b@biologie.uni-freiburg.de>
Message-ID: <o4qka1$vdu$2@blaine.gmane.org>

Wolfgang Maier wrote:

> On 1/6/2017 15:04, Peter Otten wrote:
>> Example: you are looking for the minimum absolute value in a series of
>> integers. As soon as you encounter the first 0 it's unnecessary extra
>> work to check the remaining values, but the builtin min() will continue.
>>
>> The solution is a minimum function that allows the user to specify a stop
>> value:
>>
>>>>> from itertools import count, chain
>>>>> stopmin(chain(reversed(range(10)), count()), key=abs, stop=0)
>> 0
>>
>> How would you implement stopmin()?
>>
> 
> How about:
> 
> def stopmin (iterable, key, stop):
>      def take_until ():
>          for e in iterable:
>              yield e
>              if key(e) <= stop:
>                  break
>      return min(take_until(), key=key)
> 
> ?

Clean and simple -- if it could be tweaked to invoke key() just once per 
item it would be perfect.



From __peter__ at web.de  Sat Jan  7 06:45:24 2017
From: __peter__ at web.de (Peter Otten)
Date: Sat, 07 Jan 2017 12:45:24 +0100
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com>
Message-ID: <o4qkcf$vdu$3@blaine.gmane.org>

Paul Rubin wrote:

> Peter Otten <__peter__ at web.de> writes:
>> How would you implement stopmin()?
> 
> Use itertools.takewhile

I should have mentioned that I had already run into that -- let's call it -- 
off-by-one bug.



From __peter__ at web.de  Sat Jan  7 06:55:12 2017
From: __peter__ at web.de (Peter Otten)
Date: Sat, 07 Jan 2017 12:55:12 +0100
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <5870a057$0$1585$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <o4qkus$eol$1@blaine.gmane.org>

Steve D'Aprano wrote:

> On Sat, 7 Jan 2017 01:04 am, Peter Otten wrote:
> 
>> Example: you are looking for the minimum absolute value in a series of
>> integers. As soon as you encounter the first 0 it's unnecessary extra
>> work to check the remaining values, but the builtin min() will continue.
>> 
>> The solution is a minimum function that allows the user to specify a stop
>> value:
>> 
>>>>> from itertools import count, chain
>>>>> stopmin(chain(reversed(range(10)), count()), key=abs, stop=0)
>> 0
>> 
>> How would you implement stopmin()?
> 
> That depends on whether you want to stop when you find a value *equal* to
> the stop value, or *less than* the stop value, or both.
> 
> It depends on whether you want to check for equality or check for any
> arbitrary condition.
> 
> It depends on whether you want the stop value to be included or not. (It
> looks like you do want it included.)
> 
> But I'd start with this:
> 
> 
> # not tested
> def stopmin(iterable, key=None, stop=None):
>     it = iter(iterable)
>     try:
>         smallest = next(it)
>     except StopIteration:
>         raise ValueError('empty iterable has no minimum')
>     else:
>         if key is not None:
>             keyed_smallest = key(smallest)

Must test for stop here.

>     if key is None:
>         for x in iterable:

Replace `iterable` with `it` in the for loops.

>             if x < smallest:
>                 smallest = x
>             if x == stop:
>                 break
>     else:
>         for x in iterable:
>             y = key(x)
>             if y < keyed_smallest:
>                 keyed_smallest = y
>                 smallest = x
>             if y == stop:
>                 break
>     return smallest

The whole distraction started when I wanted to avoid the straight-forward 
thing ;) 

As it turns out there is not as much legwork as I expected, particularly as 
I'm not interested in the no-key branch.
 
> Another possibility is to create a variant of itertools takewhile:
> 
> def takeuntil(predicate, iterable):
>     # takeuntil(lambda x: x<5, [1,4,6,4,1]) --> 1 4 6
>     for x in iterable:
>         yield x
>         if predicate(x):
>             break
> 
> min(takeuntil(lambda x: x == 0, iterable), key=abs)
> 
> 
> py> from itertools import count, chain
> py> iterable = chain(reversed(range(10)), count())
> py> min(takeuntil(lambda x: x == 0, iterable), key=abs)
> 0
> py> iterable = chain(range(-9, 10), count())
> py> min(takeuntil(lambda x: x == 0, iterable), key=abs)
> 0




From __peter__ at web.de  Sat Jan  7 07:15:22 2017
From: __peter__ at web.de (Peter Otten)
Date: Sat, 07 Jan 2017 13:15:22 +0100
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
Message-ID: <o4qm4m$tal$1@blaine.gmane.org>

Peter Otten wrote:

> Example: you are looking for the minimum absolute value in a series of
> integers. As soon as you encounter the first 0 it's unnecessary extra work
> to check the remaining values, but the builtin min() will continue.
> 
> The solution is a minimum function that allows the user to specify a stop
> value:

Thanks everyone who contributed to this thread!

For those interested here's my collection of stopmin() implementations so 
far. Remember, there should be one ... *obvious* way to do it (emphasis 
mine).

$ cat stopmin_simple.py               
import functools
import operator
import re

from itertools import groupby
from functools import lru_cache


def steal_doc(f):
    def set_doc(g):
        sub = re.compile(r"\b{}\b".format(f.__name__)).sub
        g.__doc__ = sub(g.__name__, f.__doc__)
        return g
    return set_doc


class Stop(Exception):
    pass


def stopmin(items, *, key, stop):
    """
    >>> def g():
    ...     for i in reversed(range(10)):
    ...         print(10*i)
    ...         yield str(i)
    >>> stopmin(g(), key=int, stop=5)
    90
    80
    70
    60
    50
    '5'
    >>> stopmin(g(), key=int, stop=8.5)
    90
    80
    '8'
    >>> stopmin(g(), key=int, stop=9)
    90
    '9'
    >>> stopmin([10, 9, -11, 7, -12], key=abs, stop=0)
    7
    >>> try: stopmin([], key=abs, stop=0)
    ... except ValueError: print('OK')
    OK
    >>> stopmin("a", key=lambda x: print(x) or "c", stop="b")
    a
    'a'
    """
    def key2(value):
        result = key(value)
        if result <= stop:
            raise Stop(value)
        return result
    try:
        return min(items, key=key2)
    except Stop as stop:
        return stop.args[0]


def takeuntil(data, pred):
    '''Take values from data until and including the first that
    satisfies pred (until data is exhausted if none does).'''
    for kind, group in groupby(data, pred):
        if kind:
            yield next(group)
            break
        else:
            yield from group


@steal_doc(stopmin)
def stopmin_jussi(data, *, key, stop):
    key = lru_cache(maxsize=1)(key)
    return min(
        takeuntil(data, lambda o: key(o) <= stop),
        key=key
    )


@steal_doc(stopmin)
def stopmin_wolfgang(iterable, *, key, stop):
    key = lru_cache(maxsize=1)(key)

    def take_until():
        for e in iterable:
            yield e
            if key(e) <= stop:
                break
    return min(take_until(), key=key)


firstitem = operator.itemgetter(0)


@steal_doc(stopmin)
def stopmin_du(items, *, key, stop):
    # decorate, process, undecorate
    pairs = ((key(item), item) for item in items)
    pairs = takeuntil(pairs, lambda pair: pair[0] <= stop)
    return min(pairs, key=firstitem)[1]


@functools.total_ordering
class Pair:
    __slots__ = ["key", "value"]

    def __init__(self, key, value):
        self.key = key
        self.value = value

    def __lt__(self, other):
        return self.key < other.key


@steal_doc(stopmin)
def stopmin_du2(items, *, key, stop):
    pairs = (Pair(key(item), item) for item in items)
    pairs = takeuntil(pairs, lambda p: p.key <= stop)
    return min(pairs).value


@steal_doc(stopmin)
def stopmin_steve(iterable, *, key, stop):
    it = iter(iterable)
    try:
        smallest = next(it)
    except StopIteration:
        raise ValueError('empty iterable has no minimum')
    keyed_smallest = key(smallest)
    if keyed_smallest <= stop:
        return smallest
    for x in it:
        y = key(x)
        if y < keyed_smallest:
            keyed_smallest = y
            smallest = x
        if y <= stop:
            break
    return smallest


@steal_doc(stopmin)
def stopmin2(items, key, stop):
    pairs = ((key(item), item) for item in items)
    try:
        minkey, minval = next(pairs)
    except StopIteration:
        raise ValueError("stopmin2() arg is an empty sequence")
    if minkey <= stop:
        return minval
    for k, v in pairs:
        if k < minkey:
            if k <= stop:
                return v
            minkey = k
            minval = v
    return minval
$ pep8 stopmin_simple.py
$ python3 -m doctest stopmin_simple.py




From rustompmody at gmail.com  Sat Jan  7 10:14:58 2017
From: rustompmody at gmail.com (Rustom Mody)
Date: Sat, 7 Jan 2017 07:14:58 -0800 (PST)
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
In-Reply-To: <lf5d1fzs2yx.fsf@ling.helsinki.fi>
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com> <lf5h95bs6it.fsf@ling.helsinki.fi>
 <029aea48-3f1f-4a99-8a3b-6e8a906cbdfd@googlegroups.com>
 <lf5d1fzs2yx.fsf@ling.helsinki.fi>
Message-ID: <d1eac55a-6ad8-44b4-ac65-a2a073778d53@googlegroups.com>

On Saturday, January 7, 2017 at 1:42:47 PM UTC+5:30, Jussi Piitulainen wrote:
> Rustom Mody writes:
> 
> > On Saturday, Jussi Piitulainen wrote:
> >> Paul Rubin writes:
> >> 
> >> > Peter Otten writes:
> >> >> How would you implement stopmin()?
> >> >
> >> > Use itertools.takewhile
> >> 
> >> How? It consumes the crucial stop element:
> >> 
> >>    it = iter('what?')
> >>    list(takewhile(str.isalpha, it)) # ==> ['w', 'h', 'a', 't']
> >>    next(it, 42) # ==> 42
> >
> > I was also wondering how?
> > In a lazy language (eg haskell) with non-strict foldr (reduce but
> > rightwards) supplied non-strict operator this is trivial.
> > ie in python idiom with reduce being right_reduce
> > reduce(operator.mul, [1,2,0,4,...], 1)
> > the reduction would stop at the 0
> > Not sure how to simulate this in a strict language like python
> > Making fold(r) non-strict by using generators is ok
> > How to pass a non-strict operator?
> 
> I think it would have to be some really awkward pseudo-operator that
> throws an exception when it encounters its zero, and then reduce (or
> something outside reduce) would catch that exception. Something like
> that could be done but it would still be awkward. Don't wanna :)
> 
> You switched to a simpler operator. Would Haskell notice that
> 
>    def minabs(x, y): return min(x, y, key = abs)
> 
> has a meaningful zero? Surely it has its limits somewhere and then the
> programmer needs to supply the information.



Over ? multiply has 1 identity and 0 absorbent
min has ? as identity and 0 as absorbent
If you allow for ? they are quite the same

Below I am pretending that 100 = ?

Here are two lazy functions:
mul.0.y = 0  -- Lazy in y ie y not evaluated
mul.x.y = x*y

minm.0.y = 0  -- likewise lazy in y
minm.x.y = min.x.y

Now at the interpreter:
? foldr.minm . 100.[1,2,3,4]
1 : Int
? foldr.minm . 100.[1,2,3,4,0]
0 : Int
? foldr.minm . 100.([1,2,3,4,0]++[1...])
0 : Int

The last expression appended [1,2,3,4,0] to the infinite list of numbers.

More succinctly:
? foldr.minm . 100.([1,2,3,4,0]++undefined)
0 : Int

Both these are extremal examples of what Peter is asking for ? avoiding an 
expensive computation


From alister.ware at ntlworld.com  Sat Jan  7 10:33:22 2017
From: alister.ware at ntlworld.com (alister)
Date: Sat, 07 Jan 2017 15:33:22 GMT
Subject: Pexpect
References: <1324722496@f38.n261.z1.binkp.net>
Message-ID: <6T7cA.702399$7m2.516222@fx37.am4>

On Fri, 06 Jan 2017 12:00:32 +1200, Iranna Mathapati wrote:

> Hi Team,
> 
> How to match latter(caps and small) ,numbers and # symbol in python
> pexpect.
> 
> 
> Thanks,
> Iranna M

Simple
just write a small program
 



-- 
New screensaver released: Curtains for Windows.


From jussi.piitulainen at helsinki.fi  Sat Jan  7 11:38:16 2017
From: jussi.piitulainen at helsinki.fi (Jussi Piitulainen)
Date: Sat, 07 Jan 2017 18:38:16 +0200
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com> <lf5h95bs6it.fsf@ling.helsinki.fi>
 <029aea48-3f1f-4a99-8a3b-6e8a906cbdfd@googlegroups.com>
 <lf5d1fzs2yx.fsf@ling.helsinki.fi>
 <d1eac55a-6ad8-44b4-ac65-a2a073778d53@googlegroups.com>
Message-ID: <lf560lq4yh3.fsf@ling.helsinki.fi>

Rustom Mody writes:
> On a Saturday, Jussi Piitulainen wrote:

[snip]

>> You switched to a simpler operator. Would Haskell notice that
>> 
>>    def minabs(x, y): return min(x, y, key = abs)
>> 
>> has a meaningful zero? Surely it has its limits somewhere and then
>> the programmer needs to supply the information.
>
> Over ? multiply has 1 identity and 0 absorbent
> min has ? as identity and 0 as absorbent
> If you allow for ? they are quite the same

There is nothing like ? in Python ints. Floats would have one, but we
can leave empty minimum undefined instead. No worries.

> Below I am pretending that 100 = ?

Quite silly but fortunately not really relevant.

> Here are two lazy functions:
> mul.0.y = 0  -- Lazy in y ie y not evaluated
> mul.x.y = x*y
>
> minm.0.y = 0  -- likewise lazy in y
> minm.x.y = min.x.y

Now I don't see any reason to avoid the actual function that's been the
example in this thread:

minabs.0.y = 0
minabs.x.y = x if abs.x <= abs.y else y 

And now I see where the desired behaviour comes from in Haskell. The
absorbing clause is redundant, apart from providing the specific
stopping condition explicitly.

> Now at the interpreter:
> ? foldr.minm . 100.[1,2,3,4]
> 1 : Int
> ? foldr.minm . 100.[1,2,3,4,0]
> 0 : Int
> ? foldr.minm . 100.([1,2,3,4,0]++[1...])
> 0 : Int
>
> The last expression appended [1,2,3,4,0] to the infinite list of numbers.
>
> More succinctly:
> ? foldr.minm . 100.([1,2,3,4,0]++undefined)
> 0 : Int
>
> Both these are extremal examples of what Peter is asking for ? avoiding an 
> expensive computation

Ok. Thanks.


From jf_byrnes at comcast.net  Sat Jan  7 13:22:45 2017
From: jf_byrnes at comcast.net (jim)
Date: Sat, 7 Jan 2017 12:22:45 -0600
Subject: Using sudo with pip3?
In-Reply-To: <20170107022424.GA68905@cskk.homeip.net>
References: <CAO6+pgJScW71-M3cZjLA6AYVAVgjEt488T9s+F-_0c7B+u-=pg@mail.gmail.com>
 <20170107022424.GA68905@cskk.homeip.net>
Message-ID: <o4rblh$s2n$1@blaine.gmane.org>

On 01/06/2017 08:24 PM, Cameron Simpson wrote:
> On 06Jan2017 23:03, Clint Moyer <contact at clintmoyer.com> wrote:

Thanks everyone for the advice. Please note in my following comments I 
am not arguing with anyone, merely trying to understand. I am not a 
professional programmer, just someone who enjoys programing for my own 
use/enjoyment and I am the only user of this system.

>> Packages supplied by your distribution can be trusted more than packages
>> from PyPi. Just my two cents.
>> Most distros offer nearly all the useful Python modules directly from the
>> repo.
>
> I would agree with this on the whole. And also that it is generally
> better to add modules to your system python via the distro's repo
> because that bring benefit to every user on the system, not just yourself.

What is "system python"? If I do $ which python I get /usr/bin/python 
which points to python 2.7xx. So if everything I added was for python 3 
either using pip3 or apt-get would I be adding to "system python"?

I see that most of the "major" python3 modules I had installed, with the 
exception of scripy, are in the repository. If I upgraded one of the 
repository modules using pip3 would I lose the benefits of installing 
from the repository? I know it seems to be possible as I installed pip3 
from the repository.  The first time I used it to install a module it 
informed me there was a more current version available and showed me the 
command to update. I updated and it seems to be fine.

>> Virtual environments are great, but if you want to add libraries to your
>> system interpreter I'd recommend a simple sync through your repo.
>
> I'm directly advocating _not_ adding PyPI packages to the system
> interpreter.  If nothing else, they may differ in behaviour and
> potentially actually break system behaviour.
>
> Having your on virtualenv is good for: adding packages no provided by
> your vendor, adding packages deliberately different from those from your
> vendor (eg newer versions with specific bugfixes or extra features),
> having an isolated environment for packages (you can make more than one
> virtual environment).
>
> And of course it avoids interfering with your system python install.

A number of years ago I had virtualenv installed.  At the time I 
remember it took me a while to get it installed and working. Right now I 
am working on some scripts to download some financial date using 
Selenium and paste it into Libreoffice Calc spreadsheets.  Will using 
virtualenv have any effect on me running those scripts?

Thanks,  Jim

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




From contact at clintmoyer.com  Sat Jan  7 13:39:40 2017
From: contact at clintmoyer.com (Clint Moyer)
Date: Sat, 7 Jan 2017 11:39:40 -0700
Subject: Using sudo with pip3?
In-Reply-To: <o4rblh$s2n$1@blaine.gmane.org>
References: <CAO6+pgJScW71-M3cZjLA6AYVAVgjEt488T9s+F-_0c7B+u-=pg@mail.gmail.com>
 <20170107022424.GA68905@cskk.homeip.net> <o4rblh$s2n$1@blaine.gmane.org>
Message-ID: <CAO6+pgJGQA8-TapdAYN5e9n5SmJnvNhcrZX8WrFaWhaZQY583w@mail.gmail.com>

All Linux operating systems come with Python installed, with more
recent systems such as Arch defaulting /usr/bin/python to Python3,
since Python2 discontinued some 7-9 years ago. I believe Ubuntu still
defaults that to Python2, however.

So when you run pip3 you are attempting to download and install a
package from the internet, specifically the PyPi repository. You are
deliberately avoiding your Package Repository from your OS in this
scenario. That's fine, but when the package requires root privilege to
install arbitrary executables and bindings in the root filesystem, you
are taking on too much risk to be acceptable.

Which is why nearly all current Linux OS systems have these common
Python packages ready for instant download, through the respective
repo.

I find the benefit of adding libraries directly to your system's
Python, outweighs the extra effort of setting up a VirtualEnv. When it
comes to individual projects, that's when I'll set up the env. Being
able to run those commands directly:

$ ansible-playbook run.yml

Is quite useful. Working in the field, sadly the most common
roadblocks I see are difficulties installing through Pip, or even a
VirtualEnv. Much better off going through your system, and learning
what other dependencies may be needed.
--
Clint


On Sat, Jan 7, 2017 at 11:22 AM, jim <jf_byrnes at comcast.net> wrote:
> On 01/06/2017 08:24 PM, Cameron Simpson wrote:
>>
>> On 06Jan2017 23:03, Clint Moyer <contact at clintmoyer.com> wrote:
>
>
> Thanks everyone for the advice. Please note in my following comments I am
> not arguing with anyone, merely trying to understand. I am not a
> professional programmer, just someone who enjoys programing for my own
> use/enjoyment and I am the only user of this system.
>
>>> Packages supplied by your distribution can be trusted more than packages
>>> from PyPi. Just my two cents.
>>> Most distros offer nearly all the useful Python modules directly from the
>>> repo.
>>
>>
>> I would agree with this on the whole. And also that it is generally
>> better to add modules to your system python via the distro's repo
>> because that bring benefit to every user on the system, not just yourself.
>
>
> What is "system python"? If I do $ which python I get /usr/bin/python which
> points to python 2.7xx. So if everything I added was for python 3 either
> using pip3 or apt-get would I be adding to "system python"?
>
> I see that most of the "major" python3 modules I had installed, with the
> exception of scripy, are in the repository. If I upgraded one of the
> repository modules using pip3 would I lose the benefits of installing from
> the repository? I know it seems to be possible as I installed pip3 from the
> repository.  The first time I used it to install a module it informed me
> there was a more current version available and showed me the command to
> update. I updated and it seems to be fine.
>
>>> Virtual environments are great, but if you want to add libraries to your
>>> system interpreter I'd recommend a simple sync through your repo.
>>
>>
>> I'm directly advocating _not_ adding PyPI packages to the system
>> interpreter.  If nothing else, they may differ in behaviour and
>> potentially actually break system behaviour.
>>
>> Having your on virtualenv is good for: adding packages no provided by
>> your vendor, adding packages deliberately different from those from your
>> vendor (eg newer versions with specific bugfixes or extra features),
>> having an isolated environment for packages (you can make more than one
>> virtual environment).
>>
>> And of course it avoids interfering with your system python install.
>
>
> A number of years ago I had virtualenv installed.  At the time I remember it
> took me a while to get it installed and working. Right now I am working on
> some scripts to download some financial date using Selenium and paste it
> into Libreoffice Calc spreadsheets.  Will using virtualenv have any effect
> on me running those scripts?
>
> Thanks,  Jim
>
>
>>
>> Cheers,
>> Cameron Simpson <cs at zip.com.au>
>
>
>
> --
> https://mail.python.org/mailman/listinfo/python-list


From ethan at stoneleaf.us  Sat Jan  7 14:05:28 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Sat, 07 Jan 2017 11:05:28 -0800
Subject: The hardest problem in computer science...
In-Reply-To: <587099fa$0$1610$c3e8da3$5496439d@news.astraweb.com>
References: <586f95ac$0$1589$c3e8da3$5496439d@news.astraweb.com>
 <587099fa$0$1610$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <58713BF8.7080803@stoneleaf.us>

On 01/06/2017 11:34 PM, Steve D'Aprano wrote:
> On Sat, 7 Jan 2017 12:03 am, Steve D'Aprano wrote:
>
>> The second hardest problem in computer science is cache invalidation.
>>
>> The *hardest* problem is naming things.
>
> After puzzling over this for three days, it suddenly hit me:
>
> Theme = namedtuple("Theme", "vline tee corner")
>
> DEFAULT = Theme("?  ", "?? ", "?? ")
> BOLD = Theme("?  ", "?? ", "?? ")
> ASCII = Theme("|  ", "|- ", "+- ")
>
> def draw_tree(tree, theme=DEFAULT):
>      ...

Ya know, that looks an /awful/ lot like a collection!  Maybe even an Enum?  ;)

-- 8< -------------------------------------------------------
from aenum import Enum   # note the 'a' before the 'enum'  :)

class Theme(Enum, init='v vr llc'):
     DEFAULT = "?  ", "?? ", "?? "
     BOLD = "?  ", "?? ", "?? "
     ASCII = "|  ", "|- ", "+- "

def draw_tree(tree, theme=Theme.DEFAULT):
     print(theme.v)
     print(theme.vr)
     print(theme.v)
     print(theme.llc)

draw_tree(None)
-- 8< -------------------------------------------------------

--
~Ethan~


From cmpython at gmail.com  Sat Jan  7 16:40:42 2017
From: cmpython at gmail.com (CM)
Date: Sat, 7 Jan 2017 13:40:42 -0800 (PST)
Subject: Can't match str/unicode
Message-ID: <821e460c-1bf1-4062-9984-03ec1e110fe1@googlegroups.com>

This is probably very simple but I get confused when it comes to encoding and am generally rusty. (What follows is in Python 2.7; I know.).

I'm scraping a Word docx using win32com and am just trying to do some matching rules to find certain paragraphs that, for testing purposes, equal the word 'match', which I know exists as its own "paragraph" in the target document. First, this is at the top of the file:

#!/usr/bin/env python
# -*- coding: utf-8 -*-

Then this is the relevant code:

candidate_text = Paragraph.Range.Text.encode('utf-8')
print 'This is candidate_text:', candidate_text
print type(candidate_text)   
print type('match')
print candidate_text == 'match'
if candidate_text == 'match':
 #  do something...

And that section produces this:

This is candidate_text: match
<type 'str'>
<type 'str'>
False

and, of course, doesn't enter that "do something" loop since apparently candidate_text != 'match'...even though it seems like it does.

So what's going on here? Why isn't a string with the content 'match' equal to another string with the content 'match'?

I've also tried it with removing that .encode part and the encoding part at the very top, but then the candidate_text is a unicode object that I also can't get to match to anything.

What am I doing wrong? How should I approach this? Thanks.


From ethan at stoneleaf.us  Sat Jan  7 16:48:53 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Sat, 07 Jan 2017 13:48:53 -0800
Subject: python 3 dict: .keys(), .values(), and .item()
Message-ID: <58716245.3010102@stoneleaf.us>

In Python 2 we have:

   dict().keys()   \
   dict().items()   -->  separate list() of the results
   dict().values() /

and

   dict().iter_keys()   \
   dict().iter_items()   -->  integrated iter() of the results
   dict().iter_values() /

By "separate list" I mean a snapshot of the dict at the time, and by
"integrated iter()" I mean  changes to the dict during iteration are
seen by the iter.

In Python 3 the iter_* methods replaced the list() type methods, which
makes sense from the point-of-view of moving to a more iterator based
language; however, as a result of that change the typical "iterate over
a dict" operation now has a built-in gotcha: modifying the dict during
the iteration can now cause exceptions.

The solution, of course, is simple: surround the iterator call with list():

   list(dict.keys())
   list(dict.items())
   list(dict.values())

   for k, v in list(flag._value2member_map_.items()):
       ...

The solution, however, feels a lot more boilerplate-ish.  Either the
programmer takes a lot more care to remember the current state of the dict
(since it's no longer a snapshot), or "list()" is sprinkled around every
iterator access.

In other words, what used to be a completely safe operation now is not.

Thoughts?

--
~Ethan~


From torriem at gmail.com  Sat Jan  7 17:34:51 2017
From: torriem at gmail.com (Michael Torrie)
Date: Sat, 7 Jan 2017 15:34:51 -0700
Subject: Using sudo with pip3?
In-Reply-To: <CAO6+pgJGQA8-TapdAYN5e9n5SmJnvNhcrZX8WrFaWhaZQY583w@mail.gmail.com>
References: <CAO6+pgJScW71-M3cZjLA6AYVAVgjEt488T9s+F-_0c7B+u-=pg@mail.gmail.com>
 <20170107022424.GA68905@cskk.homeip.net> <o4rblh$s2n$1@blaine.gmane.org>
 <CAO6+pgJGQA8-TapdAYN5e9n5SmJnvNhcrZX8WrFaWhaZQY583w@mail.gmail.com>
Message-ID: <4578c74c-c174-aabb-44cf-bf4cfd95ec98@gmail.com>

On 01/07/2017 11:39 AM, Clint Moyer wrote:
> All Linux operating systems come with Python installed, with more
> recent systems such as Arch defaulting /usr/bin/python to Python3,
> since Python2 discontinued some 7-9 years ago. 

Poor choice of words, in my opinion.  Python 2 has not received new
features for 7-9 years now but it certainly hasn't been "discontinued"
and won't be for some years yet, though new programming (and distros)
should be with Python 3 now.


From __peter__ at web.de  Sat Jan  7 18:04:26 2017
From: __peter__ at web.de (Peter Otten)
Date: Sun, 08 Jan 2017 00:04:26 +0100
Subject: python 3 dict: .keys(), .values(), and .item()
References: <58716245.3010102@stoneleaf.us>
Message-ID: <o4rs5n$qgo$1@blaine.gmane.org>

Ethan Furman wrote:

> In Python 2 we have:
> 
>    dict().keys()   \
>    dict().items()   -->  separate list() of the results
>    dict().values() /
> 
> and
> 
>    dict().iter_keys()   \
>    dict().iter_items()   -->  integrated iter() of the results
>    dict().iter_values() /

I guess you didn't use these as often as I did ;)

By the way, there are also the virtually unused/unknown dict.viewXXX() 
methods that are the exact? equivalent to the dict.XXX() methods in Python 
3.

> By "separate list" I mean a snapshot of the dict at the time, and by
> "integrated iter()" I mean  changes to the dict during iteration are
> seen by the iter.
> 
> In Python 3 the iter_* methods replaced the list() type methods, which
> makes sense from the point-of-view of moving to a more iterator based
> language; however, as a result of that change the typical "iterate over
> a dict" operation now has a built-in gotcha: modifying the dict during
> the iteration can now cause exceptions.
> 
> The solution, of course, is simple: surround the iterator call with
> list():
> 
>    list(dict.keys())
>    list(dict.items())
>    list(dict.values())
> 
>    for k, v in list(flag._value2member_map_.items()):
>        ...
> 
> The solution, however, feels a lot more boilerplate-ish.  Either the
> programmer takes a lot more care to remember the current state of the dict
> (since it's no longer a snapshot), or "list()" is sprinkled around every
> iterator access.
> 
> In other words, what used to be a completely safe operation now is not.
> 
> Thoughts?

Is code that was written for Python 3 riddled with list(...) calls?

That's not my impression.

Do you see

RuntimeError: dictionary changed size during iteration

regularly? 

I don't, and while I wouldn't have changed the dict interface I think Python 
3's items() and values() -- who uses keys()? -- are clearly the better 
defaults.



From ethan at stoneleaf.us  Sat Jan  7 18:34:16 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Sat, 07 Jan 2017 15:34:16 -0800
Subject: python 3 dict: .keys(), .values(), and .item()
In-Reply-To: <o4rs5n$qgo$1@blaine.gmane.org>
References: <58716245.3010102@stoneleaf.us> <o4rs5n$qgo$1@blaine.gmane.org>
Message-ID: <58717AF8.4040901@stoneleaf.us>

On 01/07/2017 03:04 PM, Peter Otten wrote:
> Ethan Furman wrote:
>
>> In Python 2 we have:
>>
>>     dict().keys()   \
>>     dict().items()   -->  separate list() of the results
>>     dict().values() /
>>
>> and
>>
>>     dict().iter_keys()   \
>>     dict().iter_items()   -->  integrated iter() of the results
>>     dict().iter_values() /
>
> I guess you didn't use these as often as I did ;)
>
> By the way, there are also the virtually unused/unknown dict.viewXXX()
> methods that are the exact? equivalent to the dict.XXX() methods in Python
> 3.

Ah, right -- in fact, those are the ones that got transplanted, I think.

>> In other words, what used to be a completely safe operation now is not.
>>
>> Thoughts?
>
> Is code that was written for Python 3 riddled with list(...) calls?

Generally, or just around dicts?  I know I've placed list() around a few dict
calls (when I am going to modify the dict in the loop) or I make a separate list
to save the modifications and the bulk change in a separate loop.

> Do you see
>
> RuntimeError: dictionary changed size during iteration
>
> regularly?

No, thank goodness.  Still embarrassing when it happens, though.  :(

Thinking on it some more, I'm pretty sure I would have ended up with another
exception of a different flavor, so overall no extra harm done.  ;)

--
~Ethan~


From rosuav at gmail.com  Sat Jan  7 18:39:58 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 8 Jan 2017 10:39:58 +1100
Subject: Using sudo with pip3?
In-Reply-To: <4578c74c-c174-aabb-44cf-bf4cfd95ec98@gmail.com>
References: <CAO6+pgJScW71-M3cZjLA6AYVAVgjEt488T9s+F-_0c7B+u-=pg@mail.gmail.com>
 <20170107022424.GA68905@cskk.homeip.net> <o4rblh$s2n$1@blaine.gmane.org>
 <CAO6+pgJGQA8-TapdAYN5e9n5SmJnvNhcrZX8WrFaWhaZQY583w@mail.gmail.com>
 <4578c74c-c174-aabb-44cf-bf4cfd95ec98@gmail.com>
Message-ID: <CAPTjJmo_mOHqYP+JUQwLAL7HxEBxwsH7BQpJCG59xv6FOa8q3Q@mail.gmail.com>

On Sun, Jan 8, 2017 at 9:34 AM, Michael Torrie <torriem at gmail.com> wrote:
> On 01/07/2017 11:39 AM, Clint Moyer wrote:
>> All Linux operating systems come with Python installed, with more
>> recent systems such as Arch defaulting /usr/bin/python to Python3,
>> since Python2 discontinued some 7-9 years ago.
>
> Poor choice of words, in my opinion.  Python 2 has not received new
> features for 7-9 years now but it certainly hasn't been "discontinued"
> and won't be for some years yet, though new programming (and distros)
> should be with Python 3 now.

Also, /usr/bin/python shouldn't be Python 3.

https://www.python.org/dev/peps/pep-0394/

But various distros are moving towards "don't have Python 2 installed
by default", which consequently means "no system scripts depend on
Python 2".

ChrisA


From rosuav at gmail.com  Sat Jan  7 18:42:06 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 8 Jan 2017 10:42:06 +1100
Subject: Can't match str/unicode
In-Reply-To: <821e460c-1bf1-4062-9984-03ec1e110fe1@googlegroups.com>
References: <821e460c-1bf1-4062-9984-03ec1e110fe1@googlegroups.com>
Message-ID: <CAPTjJmoG2ZqvvG01XoDph8s425Q4_9UUofbJCvnuZZbrqcAuLg@mail.gmail.com>

On Sun, Jan 8, 2017 at 8:40 AM, CM <cmpython at gmail.com> wrote:
>
> This is candidate_text: match
> <type 'str'>
> <type 'str'>
> False
>
> and, of course, doesn't enter that "do something" loop since apparently candidate_text != 'match'...even though it seems like it does.
>
> So what's going on here? Why isn't a string with the content 'match' equal to another string with the content 'match'?

What happens if you print the repr of each string? Or, if one of them
truly is a literal, just print the repr of the one you got from
win32com.

ChrisA


From cs at zip.com.au  Sat Jan  7 18:51:39 2017
From: cs at zip.com.au (Cameron Simpson)
Date: Sun, 8 Jan 2017 10:51:39 +1100
Subject: Using sudo with pip3?
In-Reply-To: <o4rblh$s2n$1@blaine.gmane.org>
References: <o4rblh$s2n$1@blaine.gmane.org>
Message-ID: <20170107235139.GA45969@cskk.homeip.net>

On 07Jan2017 12:22, jim <jf_byrnes at comcast.net> wrote:
>On 01/06/2017 08:24 PM, Cameron Simpson wrote:
>>On 06Jan2017 23:03, Clint Moyer <contact at clintmoyer.com> wrote:
>>>Packages supplied by your distribution can be trusted more than packages
>>>from PyPi. Just my two cents.
>>>Most distros offer nearly all the useful Python modules directly from the
>>>repo.
>>
>>I would agree with this on the whole. And also that it is generally
>>better to add modules to your system python via the distro's repo
>>because that bring benefit to every user on the system, not just yourself.
>
>What is "system python"? If I do $ which python I get /usr/bin/python 
>which points to python 2.7xx. So if everything I added was for python 
>3 either using pip3 or apt-get would I be adding to "system python"?

Whatever python(s) came from the vendor. If they're in /bin or /usr/bin, then 
they will almost certainly be the vendor python.

The thing is, many distros will have an aim to move to python 3 as their python 
for tooling (python 2 is essentially maintenance only - see PEP 404), and there 
will be a mix of python 2 and python 3 programs on your system, both core 
vendor-made tools (eg yum on redhat/centos) or third party but vendor supplied 
stuff (== anything else that apt-get will give you).

Basicly, for Ubuntu the "system" python is anything supplied by apt-get and 
therefore _managed_ by apt. This is why you should avoid "become root and run 
pip3 install" on the whole - you may well tread in the space owned by the 
vendor because Ubuntu supply many python packages.

Normally a vendor will not install its packages in /opt or /usr/local or in 
/home/wherever; that leaves such spaces as safe for third party stuff installs.

So, instead, make a python3 virtualenv as yourself and use _its_ pip3 for 
installs; they will land in the virtualenv, away from the vendor files.

When you make a virtualenv you base it on an existing python; if you tell it to 
use /usr/bin/python3 that will be the underlying python executable, but the 
"python3" from inside the virutalenv will be configured to use the virtualenv's 
packages.

I generally configure my virtualenvs to leverag the system's packages, as this 
lets me benefit if more vendor supplied packages are added. (Some virtualenvs 
are not, in order to isolate them from changes.)

Here's an example:

  $ mkdir ~/var ~/var/venv  # where I keep my virtualenvs
  $ virtualenv -p /usr/bin/python3 --system-site-packages ~/var/venv/3
  $ ~/var/venv/3/bin/python3    # invokes the virtualenv python3
  $ ~/var/venv/3/bin/pip3       # invokes the virtualenv pip3
  $ ln -s ~/var/venv/3/bin/python3 ~/bin/.  # make these my default
  $ ln -s ~/var/venv/3/bin/pip3 ~/bin/.

From this point on "pip3" should execute your own $HOME/bin/pip3, which comes 
from the virtualenv and installs in ~/var/venv/3/lib/...

In this way:

  - you get whatever vendor supplied packages there are, including any updates


  - you can install freely with pip3 safe in the knowledge that it will be in 
    ~/var/venv/3, away from the system packages; pip3 install packages will 
    override any vendor supplied one for the venv python3

>A number of years ago I had virtualenv installed.  At the time I remember it 
>took me a while to get it installed and working.

It is almost a one liner these days, see example above.

>Right now I am working on some scripts to download some financial date using 
>Selenium and paste it into Libreoffice Calc spreadsheets.  Will using 
>virtualenv have any effect on me running those scripts?

I wouldn't think so. Especially if they already work.

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


From contact at clintmoyer.com  Sat Jan  7 18:58:45 2017
From: contact at clintmoyer.com (Clint Moyer)
Date: Sat, 7 Jan 2017 16:58:45 -0700
Subject: Using sudo with pip3?
Message-ID: <CAO6+pg+v9B2dTavcAHdm7MLUzqHQnH2BiC9t4ib6X1B3MOAE-g@mail.gmail.com>

Not sure how you guys got this thread so far off topic, but I think it
is valuable to present the current situation in the context of Jim's
sudo question. Staying on topic, the emphasis should be on taking the
path of least resistance with your current OS. The only thing to be
gleaned from PEP394 is that users should not put faith or expectations
in what their /usr/bin/python symlink points to. Most systems point to
Python2, but it is not guaranteed.

So to minimize your issues with installing Python packages, take the
path of least resistance and install through your system repo. And use
Python2 or Python3 explicitly to avoid conflicts.

--
Clint



On Sat, Jan 7, 2017 at 4:39 PM, Chris Angelico <rosuav at gmail.com> wrote:
> On Sun, Jan 8, 2017 at 9:34 AM, Michael Torrie <torriem at gmail.com> wrote:
>> On 01/07/2017 11:39 AM, Clint Moyer wrote:
>>> All Linux operating systems come with Python installed, with more
>>> recent systems such as Arch defaulting /usr/bin/python to Python3,
>>> since Python2 discontinued some 7-9 years ago.
>>
>> Poor choice of words, in my opinion.  Python 2 has not received new
>> features for 7-9 years now but it certainly hasn't been "discontinued"
>> and won't be for some years yet, though new programming (and distros)
>> should be with Python 3 now.
>
> Also, /usr/bin/python shouldn't be Python 3.
>
> https://www.python.org/dev/peps/pep-0394/
>
> But various distros are moving towards "don't have Python 2 installed
> by default", which consequently means "no system scripts depend on
> Python 2".
>
> ChrisA


From jackrharvey at hotmail.com  Sat Jan  7 19:15:30 2017
From: jackrharvey at hotmail.com (Jack Harvey)
Date: Sun, 8 Jan 2017 00:15:30 +0000
Subject: Error with math.sqrt
Message-ID: <CY1PR1001MB1083F4A7122AB4BDD3B29E73AF650@CY1PR1001MB1083.namprd10.prod.outlook.com>

I'm starting out with Python 3.5.  My current frustration is with:


>>> math.sqrt(25)
Traceback (most recent call last):
  File "<pyshell#0>", line 1, in <module>
    math.sqrt(25)
NameError: name 'math' is not defined
>>>


Advice?


Jack


From rosuav at gmail.com  Sat Jan  7 19:22:02 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 8 Jan 2017 11:22:02 +1100
Subject: Using sudo with pip3?
In-Reply-To: <20170107235139.GA45969@cskk.homeip.net>
References: <o4rblh$s2n$1@blaine.gmane.org>
 <20170107235139.GA45969@cskk.homeip.net>
Message-ID: <CAPTjJmoxOm0JJjRd-w6oRrthP+RnOZYbUmRLB3moXo2rUqzciw@mail.gmail.com>

On Sun, Jan 8, 2017 at 10:51 AM, Cameron Simpson <cs at zip.com.au> wrote:
> Here's an example:
>
>  $ mkdir ~/var ~/var/venv  # where I keep my virtualenvs
>  $ virtualenv -p /usr/bin/python3 --system-site-packages ~/var/venv/3
>  $ ~/var/venv/3/bin/python3    # invokes the virtualenv python3
>  $ ~/var/venv/3/bin/pip3       # invokes the virtualenv pip3
>  $ ln -s ~/var/venv/3/bin/python3 ~/bin/.  # make these my default
>  $ ln -s ~/var/venv/3/bin/pip3 ~/bin/.
>
> From this point on "pip3" should execute your own $HOME/bin/pip3, which
> comes from the virtualenv and installs in ~/var/venv/3/lib/...

Can you do the same with the standard library 'venv' module? I
generally recommend and prefer that over the third-party 'virtualenv',
which achieves what it does via a series of hacks.

ChrisA


From rosuav at gmail.com  Sat Jan  7 19:23:29 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 8 Jan 2017 11:23:29 +1100
Subject: Error with math.sqrt
In-Reply-To: <CY1PR1001MB1083F4A7122AB4BDD3B29E73AF650@CY1PR1001MB1083.namprd10.prod.outlook.com>
References: <CY1PR1001MB1083F4A7122AB4BDD3B29E73AF650@CY1PR1001MB1083.namprd10.prod.outlook.com>
Message-ID: <CAPTjJmqPPQC81FjGvcK-wU2-jr3tOCy7VU94m5JVQbYCug+kpg@mail.gmail.com>

On Sun, Jan 8, 2017 at 11:15 AM, Jack Harvey <jackrharvey at hotmail.com> wrote:
> I'm starting out with Python 3.5.  My current frustration is with:
>
>
>>>> math.sqrt(25)
> Traceback (most recent call last):
>   File "<pyshell#0>", line 1, in <module>
>     math.sqrt(25)
> NameError: name 'math' is not defined
>>>>
>
>
> Advice?

A lot of Python's features are in what's called the "standard library"
- a set of modules that you can call up with the 'import' statement.
In this case, all you need is to start with this line:

import math

Once you do that, everything in the math module (including math.sqrt)
should be available.

Enjoy!

ChrisA


From cs at zip.com.au  Sat Jan  7 19:48:51 2017
From: cs at zip.com.au (Cameron Simpson)
Date: Sun, 8 Jan 2017 11:48:51 +1100
Subject: Using sudo with pip3?
In-Reply-To: <CAPTjJmoxOm0JJjRd-w6oRrthP+RnOZYbUmRLB3moXo2rUqzciw@mail.gmail.com>
References: <CAPTjJmoxOm0JJjRd-w6oRrthP+RnOZYbUmRLB3moXo2rUqzciw@mail.gmail.com>
Message-ID: <20170108004851.GA32483@cskk.homeip.net>

On 08Jan2017 11:22, Chris Angelico <rosuav at gmail.com> wrote:
>On Sun, Jan 8, 2017 at 10:51 AM, Cameron Simpson <cs at zip.com.au> wrote:
>> Here's an example:
>>
>>  $ mkdir ~/var ~/var/venv  # where I keep my virtualenvs
>>  $ virtualenv -p /usr/bin/python3 --system-site-packages ~/var/venv/3
>>  $ ~/var/venv/3/bin/python3    # invokes the virtualenv python3
>>  $ ~/var/venv/3/bin/pip3       # invokes the virtualenv pip3
>>  $ ln -s ~/var/venv/3/bin/python3 ~/bin/.  # make these my default
>>  $ ln -s ~/var/venv/3/bin/pip3 ~/bin/.
>>
>> From this point on "pip3" should execute your own $HOME/bin/pip3, which
>> comes from the virtualenv and installs in ~/var/venv/3/lib/...
>
>Can you do the same with the standard library 'venv' module? I
>generally recommend and prefer that over the third-party 'virtualenv',
>which achieves what it does via a series of hacks.

Probably? Haven't tried. I thought the venv module was essentially virtualenv's 
innards presented as a module, but have never tested it.

Do I need to retire my "venv" shell script (convenience wrapper for the 
virtualenv command)?

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


From steve+python at pearwood.info  Sat Jan  7 19:48:56 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Sun, 08 Jan 2017 11:48:56 +1100
Subject: python 3 dict: .keys(), .values(), and .item()
References: <58716245.3010102@stoneleaf.us>
 <mailman.318.1483825734.2395.python-list@python.org>
Message-ID: <58718c7a$0$1587$c3e8da3$5496439d@news.astraweb.com>

On Sun, 8 Jan 2017 08:48 am, Ethan Furman wrote:

> In Python 2 we have:
> 
>    dict().keys()   \
>    dict().items()   -->  separate list() of the results
>    dict().values() /
> 
> and
> 
>    dict().iter_keys()   \
>    dict().iter_items()   -->  integrated iter() of the results
>    dict().iter_values() /

You missed another group of methods:

viewkeys()
viewitems()
viewvalues()

which are integrated, iterable, set-like views of the keys/items/values.


> By "separate list" I mean a snapshot of the dict at the time, and by
> "integrated iter()" I mean  changes to the dict during iteration are
> seen by the iter.
> 
> In Python 3 the iter_* methods replaced the list() type methods, 

Its actually the view* methods.


> which 
> makes sense from the point-of-view of moving to a more iterator based
> language; however, as a result of that change the typical "iterate over
> a dict" operation now has a built-in gotcha: modifying the dict during
> the iteration can now cause exceptions.

Even in Python 2, modifying the dict during iteration can cause exceptions:

for key in adict:  # iterate over the dict directly
    ...


As usual, the standard rule applies: don't add or remove elements of a
collection while you are iterating over it.

This doesn't work either:

for i, x in enumerate(alist):
    if condition(x):
        del alist(i)


and has a similar solution:

for i, x in enumerate(list(alist)):
    ...

except that's more commonly written using slicing:

for i, x in enumerate(alist[:]):
    ...


For both dicts and lists, it is safe to modify existing elements:

    adict[key] = new_value  # provided key already exists

    alist[index] = new_value


are both safe, but insertions and deletions are not.


> The solution, of course, is simple: surround the iterator call with
> list():

There's nothing magical about list. You could use tuple, or (sometimes) set
or frozenset. But list is good.


>    list(dict.keys())
>    list(dict.items())
>    list(dict.values())
> 
>    for k, v in list(flag._value2member_map_.items()):
>        ...
> 
> The solution, however, feels a lot more boilerplate-ish.  Either the
> programmer takes a lot more care to remember the current state of the dict
> (since it's no longer a snapshot), or "list()" is sprinkled around every
> iterator access.

Not *every* view access. Only the ones where you insert/delete elements.


> In other words, what used to be a completely safe operation now is not.
> 
> Thoughts?

The old Python 2 keys/values/items methods used to make a copy of the
elements, whether you needed a copy or not. Now making a copy is your
responsibility. That feels more Pythonic to me.



-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From steve+python at pearwood.info  Sat Jan  7 19:58:51 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Sun, 08 Jan 2017 11:58:51 +1100
Subject: Can't match str/unicode
References: <821e460c-1bf1-4062-9984-03ec1e110fe1@googlegroups.com>
Message-ID: <58718ecd$0$1611$c3e8da3$5496439d@news.astraweb.com>

On Sun, 8 Jan 2017 08:40 am, CM wrote:

> So what's going on here? Why isn't a string with the content 'match' equal
> to another string with the content 'match'?

You don't know that the content is 'match'. All you know is that when
printed, it *looks like* 'match'.

Hint:

s = 'match '
print 'match', s  # they look the same
print 'match' == s  # but they aren't the same


Start by printing repr(candidate_text) and see what you really have.




-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From jf_byrnes at comcast.net  Sat Jan  7 20:02:14 2017
From: jf_byrnes at comcast.net (jim)
Date: Sat, 7 Jan 2017 19:02:14 -0600
Subject: Using sudo with pip3?
In-Reply-To: <efm27c9hij6sd3dsegscl0ec9u1dnpbs5k@4ax.com>
References: <CAO6+pgJScW71-M3cZjLA6AYVAVgjEt488T9s+F-_0c7B+u-=pg@mail.gmail.com>
 <20170107022424.GA68905@cskk.homeip.net> <o4rblh$s2n$1@blaine.gmane.org>
 <efm27c9hij6sd3dsegscl0ec9u1dnpbs5k@4ax.com>
Message-ID: <o4s32h$d12$1@blaine.gmane.org>

On 01/07/2017 03:17 PM, Dennis Lee Bieber wrote:
> On Sat, 7 Jan 2017 12:22:45 -0600, jim <jf_byrnes at comcast.net> declaimed
> the following:
>
>>
>> What is "system python"? If I do $ which python I get /usr/bin/python
>> which points to python 2.7xx. So if everything I added was for python 3
>> either using pip3 or apt-get would I be adding to "system python"?
>>
>
> 	What does
>
> 		which python3
>
> return?

jfb at jims-1604:~$ which python3
/usr/bin/python3

Regards,  Jim

> wulfraed at Jessie:~$ which python
> /usr/bin/python
> wulfraed at Jessie:~$ which python3
> /usr/bin/python3
> wulfraed at Jessie:~$ python
> Python 2.7.9 (default, Mar  1 2015, 12:57:24)
> [GCC 4.9.2] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
>>>>
> wulfraed at Jessie:~$ 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.
>>>>
> wulfraed at Jessie:~$
>
> 	I consider both of those to be "system" as I don't recall explicitly
> asking for either (Debian running in VirtualBox)
>




From jf_byrnes at comcast.net  Sat Jan  7 20:45:17 2017
From: jf_byrnes at comcast.net (jim)
Date: Sat, 7 Jan 2017 19:45:17 -0600
Subject: Using sudo with pip3?
In-Reply-To: <CAO6+pg+v9B2dTavcAHdm7MLUzqHQnH2BiC9t4ib6X1B3MOAE-g@mail.gmail.com>
References: <CAO6+pg+v9B2dTavcAHdm7MLUzqHQnH2BiC9t4ib6X1B3MOAE-g@mail.gmail.com>
Message-ID: <o4s5j9$ntg$1@blaine.gmane.org>

On 01/07/2017 05:58 PM, Clint Moyer wrote:
> Not sure how you guys got this thread so far off topic, but I think it
> is valuable to present the current situation in the context of Jim's
> sudo question. Staying on topic, the emphasis should be on taking the
> path of least resistance with your current OS. The only thing to be
> gleaned from PEP394 is that users should not put faith or expectations
> in what their /usr/bin/python symlink points to. Most systems point to
> Python2, but it is not guaranteed.
>
> So to minimize your issues with installing Python packages, take the
> path of least resistance and install through your system repo. And use
> Python2 or Python3 explicitly to avoid conflicts.
>
> --
> Clint
>

As I mentioned in another post, most of the more popular modules I had 
installed on my old system using pip are available in the repository and 
I will use the repository to install them on the new system. I now 
understand that using sudo is a bad idea.

One question from the earlier post that did not get answered concerned 
upgrading a repository installed module with pip. To get started on the 
new system I installed pip3 from the repository. The first time I used 
it to install a module it said a newer version was available and gave 
the command to update it. What are the consequences of using pip to 
upgrade repository installed modules?

I ask because 16.04 is LTS and won't be getting version upgrades unless 
they are security related. Also pandas is in the repositories but the 
module pandas-datareader, which I may need to use, is not.

Regards,  Jim

>
> On Sat, Jan 7, 2017 at 4:39 PM, Chris Angelico <rosuav at gmail.com> wrote:
>> On Sun, Jan 8, 2017 at 9:34 AM, Michael Torrie <torriem at gmail.com> wrote:
>>> On 01/07/2017 11:39 AM, Clint Moyer wrote:
>>>> All Linux operating systems come with Python installed, with more
>>>> recent systems such as Arch defaulting /usr/bin/python to Python3,
>>>> since Python2 discontinued some 7-9 years ago.
>>>
>>> Poor choice of words, in my opinion.  Python 2 has not received new
>>> features for 7-9 years now but it certainly hasn't been "discontinued"
>>> and won't be for some years yet, though new programming (and distros)
>>> should be with Python 3 now.
>>
>> Also, /usr/bin/python shouldn't be Python 3.
>>
>> https://www.python.org/dev/peps/pep-0394/
>>
>> But various distros are moving towards "don't have Python 2 installed
>> by default", which consequently means "no system scripts depend on
>> Python 2".
>>
>> ChrisA




From plucena24 at gmail.com  Sat Jan  7 20:56:30 2017
From: plucena24 at gmail.com (Pablo Lucena)
Date: Sat, 7 Jan 2017 17:56:30 -0800
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
In-Reply-To: <lf560lq4yh3.fsf@ling.helsinki.fi>
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com> <lf5h95bs6it.fsf@ling.helsinki.fi>
 <029aea48-3f1f-4a99-8a3b-6e8a906cbdfd@googlegroups.com>
 <lf5d1fzs2yx.fsf@ling.helsinki.fi>
 <d1eac55a-6ad8-44b4-ac65-a2a073778d53@googlegroups.com>
 <lf560lq4yh3.fsf@ling.helsinki.fi>
Message-ID: <CAB_tDZwZf0CyGPf5dG0agJrGa54iB_6EaEeH965uCCFzngo3GA@mail.gmail.com>

How about using the second usage of builtin iter()?

In [92]: iter?
Docstring:
iter(iterable) -> iterator
iter(callable, sentinel) -> iterator

Get an iterator from an object.  In the first form, the argument must
supply its own iterator, or be a sequence.
*In the second form, the callable is called until it returns the sentinel.
 <<<-----this one <<<-------*
Type:      builtin_function_or_method


In [88]: numbers
Out[88]: [1, 9, 8, 11, 22, 4, 0, 3, 5, 6]

# create iterator over the numbers to make callable simple
# you may pre-sort or do w/e as needed of course
In [89]: numbers_it = iter(numbers)

# callable passed into iter - you may customize this
# using functools.partial if need to add function arguments
In [90]: def grab_until():
    ...:     return next(numbers_it)
    ...:

# here 0 is the 'sentinel' ('int()' would work as well as you have
# the iterator produced by iter() here stops as soon as sentinel value
# is encountered
In [91]: list(iter(grab_until, 0))
Out[91]: [1, 9, 8, 11, 22, 4]



Hope this helps

Pablo

On Sat, Jan 7, 2017 at 8:38 AM, Jussi Piitulainen <
jussi.piitulainen at helsinki.fi> wrote:

> Rustom Mody writes:
> > On a Saturday, Jussi Piitulainen wrote:
>
> [snip]
>
> >> You switched to a simpler operator. Would Haskell notice that
> >>
> >>    def minabs(x, y): return min(x, y, key = abs)
> >>
> >> has a meaningful zero? Surely it has its limits somewhere and then
> >> the programmer needs to supply the information.
> >
> > Over ? multiply has 1 identity and 0 absorbent
> > min has ? as identity and 0 as absorbent
> > If you allow for ? they are quite the same
>
> There is nothing like ? in Python ints. Floats would have one, but we
> can leave empty minimum undefined instead. No worries.
>
> > Below I am pretending that 100 = ?
>
> Quite silly but fortunately not really relevant.
>
> > Here are two lazy functions:
> > mul.0.y = 0  -- Lazy in y ie y not evaluated
> > mul.x.y = x*y
> >
> > minm.0.y = 0  -- likewise lazy in y
> > minm.x.y = min.x.y
>
> Now I don't see any reason to avoid the actual function that's been the
> example in this thread:
>
> minabs.0.y = 0
> minabs.x.y = x if abs.x <= abs.y else y
>
> And now I see where the desired behaviour comes from in Haskell. The
> absorbing clause is redundant, apart from providing the specific
> stopping condition explicitly.
>
> > Now at the interpreter:
> > ? foldr.minm . 100.[1,2,3,4]
> > 1 : Int
> > ? foldr.minm . 100.[1,2,3,4,0]
> > 0 : Int
> > ? foldr.minm . 100.([1,2,3,4,0]++[1...])
> > 0 : Int
> >
> > The last expression appended [1,2,3,4,0] to the infinite list of numbers.
> >
> > More succinctly:
> > ? foldr.minm . 100.([1,2,3,4,0]++undefined)
> > 0 : Int
> >
> > Both these are extremal examples of what Peter is asking for ? avoiding
> an
> > expensive computation
>
> Ok. Thanks.
> --
> https://mail.python.org/mailman/listinfo/python-list
>



-- 
*Pablo Lucena*


From contact at clintmoyer.com  Sat Jan  7 21:07:55 2017
From: contact at clintmoyer.com (Clint Moyer)
Date: Sat, 7 Jan 2017 19:07:55 -0700
Subject: Using sudo with pip3?
In-Reply-To: <o4s5j9$ntg$1@blaine.gmane.org>
References: <CAO6+pg+v9B2dTavcAHdm7MLUzqHQnH2BiC9t4ib6X1B3MOAE-g@mail.gmail.com>
 <o4s5j9$ntg$1@blaine.gmane.org>
Message-ID: <CAO6+pg+28J9VEPNc-pCHmBjXT2z9ja4frjZ2YW7tBJQgpjbKHQ@mail.gmail.com>

I would lightly advise against, assuming both Pip and your package
manager are trying to accomplish nearly the same thing. Stick with
updating through the repo.

If you find that the version your OS provides is out-of-date compared
to what's on PyPi or Github, then you might want to remove from your
OS and re-install through Pip, for those discrete cases. That's the
platform agnostic route.
--
Clint


On Sat, Jan 7, 2017 at 6:45 PM, jim <jf_byrnes at comcast.net> wrote:
> On 01/07/2017 05:58 PM, Clint Moyer wrote:
>>
>> Not sure how you guys got this thread so far off topic, but I think it
>> is valuable to present the current situation in the context of Jim's
>> sudo question. Staying on topic, the emphasis should be on taking the
>> path of least resistance with your current OS. The only thing to be
>> gleaned from PEP394 is that users should not put faith or expectations
>> in what their /usr/bin/python symlink points to. Most systems point to
>> Python2, but it is not guaranteed.
>>
>> So to minimize your issues with installing Python packages, take the
>> path of least resistance and install through your system repo. And use
>> Python2 or Python3 explicitly to avoid conflicts.
>>
>> --
>> Clint
>>
>
> As I mentioned in another post, most of the more popular modules I had
> installed on my old system using pip are available in the repository and I
> will use the repository to install them on the new system. I now understand
> that using sudo is a bad idea.
>
> One question from the earlier post that did not get answered concerned
> upgrading a repository installed module with pip. To get started on the new
> system I installed pip3 from the repository. The first time I used it to
> install a module it said a newer version was available and gave the command
> to update it. What are the consequences of using pip to upgrade repository
> installed modules?
>
> I ask because 16.04 is LTS and won't be getting version upgrades unless they
> are security related. Also pandas is in the repositories but the module
> pandas-datareader, which I may need to use, is not.
>
> Regards,  Jim
>
>
>>
>> On Sat, Jan 7, 2017 at 4:39 PM, Chris Angelico <rosuav at gmail.com> wrote:
>>>
>>> On Sun, Jan 8, 2017 at 9:34 AM, Michael Torrie <torriem at gmail.com> wrote:
>>>>
>>>> On 01/07/2017 11:39 AM, Clint Moyer wrote:
>>>>>
>>>>> All Linux operating systems come with Python installed, with more
>>>>> recent systems such as Arch defaulting /usr/bin/python to Python3,
>>>>> since Python2 discontinued some 7-9 years ago.
>>>>
>>>>
>>>> Poor choice of words, in my opinion.  Python 2 has not received new
>>>> features for 7-9 years now but it certainly hasn't been "discontinued"
>>>> and won't be for some years yet, though new programming (and distros)
>>>> should be with Python 3 now.
>>>
>>>
>>> Also, /usr/bin/python shouldn't be Python 3.
>>>
>>> https://www.python.org/dev/peps/pep-0394/
>>>
>>> But various distros are moving towards "don't have Python 2 installed
>>> by default", which consequently means "no system scripts depend on
>>> Python 2".
>>>
>>> ChrisA
>
>
>
> --
> https://mail.python.org/mailman/listinfo/python-list


From cs at zip.com.au  Sat Jan  7 21:31:01 2017
From: cs at zip.com.au (Cameron Simpson)
Date: Sun, 8 Jan 2017 13:31:01 +1100
Subject: Using sudo with pip3?
In-Reply-To: <o4s32h$d12$1@blaine.gmane.org>
References: <o4s32h$d12$1@blaine.gmane.org>
Message-ID: <20170108023101.GA70579@cskk.homeip.net>

On 07Jan2017 19:02, jim <jf_byrnes at comcast.net> wrote:
>On 01/07/2017 03:17 PM, Dennis Lee Bieber wrote:
>>On Sat, 7 Jan 2017 12:22:45 -0600, jim <jf_byrnes at comcast.net> declaimed
>>the following:
>>>What is "system python"? If I do $ which python I get /usr/bin/python
>>>which points to python 2.7xx. So if everything I added was for python 3
>>>either using pip3 or apt-get would I be adding to "system python"?
>>
>>	What does
>>		which python3
>>return?
>
>jfb at jims-1604:~$ which python3
>/usr/bin/python3

That is the system (Ubuntu supplied) python3. /usr/bin belongs to the vendor.

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


From cs at zip.com.au  Sat Jan  7 21:42:14 2017
From: cs at zip.com.au (Cameron Simpson)
Date: Sun, 8 Jan 2017 13:42:14 +1100
Subject: Using sudo with pip3?
In-Reply-To: <o4s5j9$ntg$1@blaine.gmane.org>
References: <o4s5j9$ntg$1@blaine.gmane.org>
Message-ID: <20170108024214.GA78154@cskk.homeip.net>

On 07Jan2017 19:45, jim <jf_byrnes at comcast.net> wrote:
>On 01/07/2017 05:58 PM, Clint Moyer wrote:
>>So to minimize your issues with installing Python packages, take the
>>path of least resistance and install through your system repo. And use
>>Python2 or Python3 explicitly to avoid conflicts.
>
>As I mentioned in another post, most of the more popular modules I had 
>installed on my old system using pip are available in the repository 
>and I will use the repository to install them on the new system. I now 
>understand that using sudo is a bad idea.

Cool.

>One question from the earlier post that did not get answered concerned 
>upgrading a repository installed module with pip.

I would recommend not. As soon as you get there:

  - if the vendor updates it, use apt-get (I know this doesn't fit your 
    situation with Ubuntu 16.04 LTS)

  - if you want a more modern version, now is the time to use virtualenv

The thing about LTS is that the vendor guarentees its stability. If you upgrade 
the vendor installed package using /usr/bin/pip (or pip3) as root, you're 
replacing the vendor supplied module with a newer one, which may break vendor 
supplied packages which use that module expected the _old_ behaviour.

So endeavour to leave the vendor suppplied stuff entirely alone except for 
apt-get style updates.

Instead, make a virtualenv an upgrade it with a newer package.

>To get started on the new system I installed pip3 from the repository. The 
>first time I used it to install a module it said a newer version was available 
>and gave the command to update it. What are the consequences of using pip to 
>upgrade repository installed modules?

In theory, if the newer version of the module installs a breaking change it can 
break things in the system which might use that module and expect its old 
behaviour. Also, _sometimes_, vendors supply patches versions of packages, 
possibly including python modules. If they're modified/patched, there is 
probably a reason. You'd be undoing that patch.

>I ask because 16.04 is LTS and won't be getting version upgrades 
>unless they are security related. Also pandas is in the repositories but the 
>module pandas-datareader, which I may need to use, is not.

Again: make a virtualenv as yourself.

Its pip can be run as yourself, therefore cannot accidentally modify system 
module. It's pip can freely upgrade a older module. If you install a module 
_not_ supplied by the vendor, the virtualenv pip can freely do that, and _also_ 
upgrade a required module should that be required (PyPI package definitions let 
a module specify required revisions of other modules it may use).

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


From no.email at nospam.invalid  Sat Jan  7 22:46:10 2017
From: no.email at nospam.invalid (Paul Rubin)
Date: Sat, 07 Jan 2017 19:46:10 -0800
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com> <lf5h95bs6it.fsf@ling.helsinki.fi>
Message-ID: <87a8b22ozh.fsf@nightsong.com>

Jussi Piitulainen <jussi.piitulainen at helsinki.fi> writes:
>> Use itertools.takewhile
> How? It consumes the crucial stop element:

Oh yucch, you're right, it takes it from both sides.  How about this:

    from itertools import takewhile, islice
    def minabs(xs):
	a = iter(xs)
	m = min(map(abs,takewhile(lambda x: x!=0, a)))
	z = list(islice(a,1))
	if z: return 0
	return m


From jf_byrnes at comcast.net  Sat Jan  7 23:26:47 2017
From: jf_byrnes at comcast.net (jim)
Date: Sat, 7 Jan 2017 22:26:47 -0600
Subject: Using sudo with pip3?
In-Reply-To: <20170108024214.GA78154@cskk.homeip.net>
References: <o4s5j9$ntg$1@blaine.gmane.org>
 <20170108024214.GA78154@cskk.homeip.net>
Message-ID: <o4sf23$os5$1@blaine.gmane.org>

On 01/07/2017 08:42 PM, Cameron Simpson wrote:
> On 07Jan2017 19:45, jim <jf_byrnes at comcast.net> wrote:
>> On 01/07/2017 05:58 PM, Clint Moyer wrote:
>>> So to minimize your issues with installing Python packages, take the
>>> path of least resistance and install through your system repo. And use
>>> Python2 or Python3 explicitly to avoid conflicts.
>>
>> As I mentioned in another post, most of the more popular modules I had
>> installed on my old system using pip are available in the repository
>> and I will use the repository to install them on the new system. I now
>> understand that using sudo is a bad idea.
>
> Cool.
>
>> One question from the earlier post that did not get answered concerned
>> upgrading a repository installed module with pip.
>
> I would recommend not. As soon as you get there:
>
>  - if the vendor updates it, use apt-get (I know this doesn't fit your
>    situation with Ubuntu 16.04 LTS)
>
>  - if you want a more modern version, now is the time to use virtualenv
>
> The thing about LTS is that the vendor guarentees its stability. If you
> upgrade the vendor installed package using /usr/bin/pip (or pip3) as
> root, you're replacing the vendor supplied module with a newer one,
> which may break vendor supplied packages which use that module expected
> the _old_ behaviour.
>
> So endeavour to leave the vendor suppplied stuff entirely alone except
> for apt-get style updates.
>
> Instead, make a virtualenv an upgrade it with a newer package.
>
>> To get started on the new system I installed pip3 from the repository.
>> The first time I used it to install a module it said a newer version
>> was available and gave the command to update it. What are the
>> consequences of using pip to upgrade repository installed modules?
>
> In theory, if the newer version of the module installs a breaking change
> it can break things in the system which might use that module and expect
> its old behaviour. Also, _sometimes_, vendors supply patches versions of
> packages, possibly including python modules. If they're
> modified/patched, there is probably a reason. You'd be undoing that patch.
>
>> I ask because 16.04 is LTS and won't be getting version upgrades
>> unless they are security related. Also pandas is in the repositories
>> but the module pandas-datareader, which I may need to use, is not.
>
> Again: make a virtualenv as yourself.
>
> Its pip can be run as yourself, therefore cannot accidentally modify
> system module. It's pip can freely upgrade a older module. If you
> install a module _not_ supplied by the vendor, the virtualenv pip can
> freely do that, and _also_ upgrade a required module should that be
> required (PyPI package definitions let a module specify required
> revisions of other modules it may use).
>
> Cheers,
> Cameron Simpson <cs at zip.com.au>

You've convinced me.  I will have to buckle down and figure out to use 
virtualenv/venv. I see Chris recommends venv. I read through PEP405 and 
this link https://docs.python.org/3.5/library/venv.html. I don't pretend 
to fully understand it all but it does seem to make a good case for 
using venv over virtualenv.

thanks,  Jim





From cmpython at gmail.com  Sat Jan  7 23:31:25 2017
From: cmpython at gmail.com (CM)
Date: Sat, 7 Jan 2017 20:31:25 -0800 (PST)
Subject: Can't match str/unicode
In-Reply-To: <mailman.324.1483832534.2395.python-list@python.org>
References: <821e460c-1bf1-4062-9984-03ec1e110fe1@googlegroups.com>
 <CAPTjJmoG2ZqvvG01XoDph8s425Q4_9UUofbJCvnuZZbrqcAuLg@mail.gmail.com>
 <mailman.324.1483832534.2395.python-list@python.org>
Message-ID: <0ce4fcd4-d183-4b50-84cd-83857d1d8f12@googlegroups.com>

On Saturday, January 7, 2017 at 6:42:25 PM UTC-5, Chris Angelico wrote:

> What happens if you print the repr of each string? Or, if one of them
> truly is a literal, just print the repr of the one you got from
> win32com.
> 
> ChrisA

Yes, that did it. The repr of that one was, in fact:

u'match /r'

Thanks!


From cmpython at gmail.com  Sat Jan  7 23:33:15 2017
From: cmpython at gmail.com (CM)
Date: Sat, 7 Jan 2017 20:33:15 -0800 (PST)
Subject: Can't match str/unicode
In-Reply-To: <58718ecd$0$1611$c3e8da3$5496439d@news.astraweb.com>
References: <821e460c-1bf1-4062-9984-03ec1e110fe1@googlegroups.com>
 <58718ecd$0$1611$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <44e508f2-6c8d-41f8-bc2f-eaeda2a35e3a@googlegroups.com>

On Saturday, January 7, 2017 at 7:59:01 PM UTC-5, Steve D'Aprano wrote:
> On Sun, 8 Jan 2017 08:40 am, CM wrote:
> 
> > So what's going on here? Why isn't a string with the content 'match' equal
> > to another string with the content 'match'?
> 
> You don't know that the content is 'match'. All you know is that when
> printed, it *looks like* 'match'.
> 
> Hint:
> 
> s = 'match '
> print 'match', s  # they look the same
> print 'match' == s  # but they aren't the same
> 
> 
> Start by printing repr(candidate_text) and see what you really have.

Yes, that did it. The repr of that one was, in fact:

u'match /r'

Thanks, that did it. Do you happen to know why that /r was appended to the unicode object in this case?


From cmpython at gmail.com  Sat Jan  7 23:38:30 2017
From: cmpython at gmail.com (CM)
Date: Sat, 7 Jan 2017 20:38:30 -0800 (PST)
Subject: What is PyOleMissing object? (win32com)
Message-ID: <45ed4da7-96ad-45b4-9535-5d73c87e9c1f@googlegroups.com>

Trying to manipulate z-order for MSOffice with win32com and wasn't sure what argument was needed. Using help on that ZOrder method gives:

>>>
Help on method ZOrder in module win32com.client.dynamic:

ZOrder(self, ZOrderCmd=<PyOleMissing object>) method of win32com.client.CDispatch instance


So, what does "<PyOleMissing object> mean in this case?


From rosuav at gmail.com  Sat Jan  7 23:46:48 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 8 Jan 2017 15:46:48 +1100
Subject: Can't match str/unicode
In-Reply-To: <0ce4fcd4-d183-4b50-84cd-83857d1d8f12@googlegroups.com>
References: <821e460c-1bf1-4062-9984-03ec1e110fe1@googlegroups.com>
 <CAPTjJmoG2ZqvvG01XoDph8s425Q4_9UUofbJCvnuZZbrqcAuLg@mail.gmail.com>
 <mailman.324.1483832534.2395.python-list@python.org>
 <0ce4fcd4-d183-4b50-84cd-83857d1d8f12@googlegroups.com>
Message-ID: <CAPTjJmpF7BZ-qeAJLXR3yx0ige3puiuvqi0Rqh6NC1DUyDDjFA@mail.gmail.com>

On Sun, Jan 8, 2017 at 3:31 PM, CM <cmpython at gmail.com> wrote:
> On Saturday, January 7, 2017 at 6:42:25 PM UTC-5, Chris Angelico wrote:
>
>> What happens if you print the repr of each string? Or, if one of them
>> truly is a literal, just print the repr of the one you got from
>> win32com.
>>
>> ChrisA
>
> Yes, that did it. The repr of that one was, in fact:
>
> u'match /r'
>
> Thanks!

Are you sure that's what it was? Copy and paste for accuracy.

ChrisA


From python at deborahswanson.net  Sun Jan  8 00:39:47 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sat, 7 Jan 2017 21:39:47 -0800
Subject: Using namedtuples field names for column indices in a list of lists
Message-ID: <004101d26971$a0395ae0$27b23dae@sambora>

What I've done so far:

with open('E:\\Coding projects\\Pycharm\\Moving\\Moving 2017 in.csv',
'r') as infile:
	ls = list(csv.reader(infile))
lst = namedtuple('lst', ls[0])

where 'ls[0]' is the header row of the csv, and it works perfectly well.
'lst' is a namedtuple instance with each of the column titles as field
names. 

And retrieving values also works:

if len(lst.Location.fget(l)) == 0:
	.
	.

Using the .fget method for each field name returns the value in the row
and column, here row 'l' and column 'Location'.

So far so good. 'lst.Location.fget(l)' is clunkier than l[lo], but it's
recognizable and it works.

But I haven't found a way to assign new values to a list element. using
namedtuple.fieldname. I think a basic problem is that namedtuples have
the properties of tuples, and you can't assign to an existing tuple
because they're immutable. Also there's the matter of
namedtuple.fieldname being a property and not an index integer, so it
doesn't work if you try to use them as indices.

If I try:    

l[lst.Location] = 'xyz'     ('l' is a list)

I get: TypeError: list indices must be integers, not property

I'm a little hopeful that namedtuples has a built-in solution. In
addition to the method fget, each field name also has a property fset:

fset = {NoneType}None

But I can't find anything in the documentation that tells what fset is
and how to use it.

Another possibility would be to map index integers to the field names in
the namedtuple, in a way that could be accessed using the namedtuple's
field names. I've looked into using map(), but the documentation is so
sketchy I couldn't see a way to do this from what is given.  And
google's no help. If anyone else has tried to do this, google can't find
it. They don't have a string of words that I could find preloaded into
their "AI" code that will turn up anything close. Most search attempts
just ignored all my search terms except 'namedtuples' and returned
general stuff on namedtuples. I looked through a few of them, but
nothing I looked at gave any useful solution to this problem. 

Anybody know how to use .fset?  Or a way to assign to list locations by
their namedtuples fieldnames and list rows?




From jussi.piitulainen at helsinki.fi  Sun Jan  8 01:06:52 2017
From: jussi.piitulainen at helsinki.fi (Jussi Piitulainen)
Date: Sun, 08 Jan 2017 08:06:52 +0200
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com> <lf5h95bs6it.fsf@ling.helsinki.fi>
 <87a8b22ozh.fsf@nightsong.com>
Message-ID: <lf5zij2t79f.fsf@ling.helsinki.fi>

Paul Rubin writes:

> Jussi Piitulainen writes:
>>> Use itertools.takewhile
>> How? It consumes the crucial stop element:
>
> Oh yucch, you're right, it takes it from both sides.  How about this:
>
>     from itertools import takewhile, islice
>     def minabs(xs):
> 	a = iter(xs)
> 	m = min(map(abs,takewhile(lambda x: x!=0, a)))
> 	z = list(islice(a,1))
> 	if z: return 0
> 	return m

That would return 0 even when there is no 0 in xs at all.

(It would also return the absolute value, not a value whose absolute
value is minimal, but that is easy to fix.)


From steve+comp.lang.python at pearwood.info  Sun Jan  8 01:17:41 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 08 Jan 2017 17:17:41 +1100
Subject: Can't match str/unicode
References: <821e460c-1bf1-4062-9984-03ec1e110fe1@googlegroups.com>
 <58718ecd$0$1611$c3e8da3$5496439d@news.astraweb.com>
 <44e508f2-6c8d-41f8-bc2f-eaeda2a35e3a@googlegroups.com>
Message-ID: <5871d987$0$11114$c3e8da3@news.astraweb.com>

On Sunday 08 January 2017 15:33, CM wrote:

> On Saturday, January 7, 2017 at 7:59:01 PM UTC-5, Steve D'Aprano wrote:
[...]
>> Start by printing repr(candidate_text) and see what you really have.
> 
> Yes, that did it. The repr of that one was, in fact:
> 
> u'match /r'

Are you sure it is a forward-slash /r rather than backslash \r?


> Thanks, that did it. Do you happen to know why that /r was appended to the
> unicode object in this case?

*shrug* 

You're the only one that can answer that, because only you know where the text 
came from. The code you showed:

candidate_text = Paragraph.Range.Text.encode('utf-8')

is a mystery, because we don't know what Paragraph is or where it comes from, 
or what .Range.Text does.

You mention "scraping a Word docx", but we have no idea how you're scraping it. 
If I had to guess, I'd guess:

- you actually mean \r rather than /r;

- paragraphs in Word docs always end with a carriage return \r;

- and whoever typed the paragraph accidentally hit the spacebar after typing 
the word "match".


But its just a guess. For all I know, the software you are using to scrape the 
docx file inserts space/r after everything.



-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From cs at zip.com.au  Sun Jan  8 01:30:29 2017
From: cs at zip.com.au (Cameron Simpson)
Date: Sun, 8 Jan 2017 17:30:29 +1100
Subject: Using sudo with pip3?
In-Reply-To: <o4sf23$os5$1@blaine.gmane.org>
References: <o4sf23$os5$1@blaine.gmane.org>
Message-ID: <20170108063029.GA21525@cskk.homeip.net>

On 07Jan2017 22:26, jim <jf_byrnes at comcast.net> wrote:
>You've convinced me.  I will have to buckle down and figure out to use 
>virtualenv/venv. I see Chris recommends venv. I read through PEP405 and this 
>link https://docs.python.org/3.5/library/venv.html. I don't pretend to fully 
>understand it all but it does seem to make a good case for using venv over 
>virtualenv.

Note that it recommends:

  python3 -m venv ...options... path/to/env_dir

which makes sure you're getting a venv based on a specific python executable; 
in the case above whatever "python3" runs -- you could invoke a different 
python 3 to use that instead.

It looks like aside from saying "python3 -m venv" instead of "virtualenv" my 
previous example recipe should pretty much work for you.

Good luck.

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


From steve+comp.lang.python at pearwood.info  Sun Jan  8 01:42:49 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 08 Jan 2017 17:42:49 +1100
Subject: Using namedtuples field names for column indices in a list of
 lists
References: <004101d26971$a0395ae0$27b23dae@sambora>
 <mailman.339.1483853977.2395.python-list@python.org>
Message-ID: <5871df6c$0$1536$c3e8da3$5496439d@news.astraweb.com>

On Sunday 08 January 2017 16:39, Deborah Swanson wrote:

> What I've done so far:
> 
> with open('E:\\Coding projects\\Pycharm\\Moving\\Moving 2017 in.csv',
> 'r') as infile:
>     ls = list(csv.reader(infile))
>     lst = namedtuple('lst', ls[0])
> 
> where 'ls[0]' is the header row of the csv, and it works perfectly well.
> 'lst' is a namedtuple instance with each of the column titles as field
> names.

Are you sure? namedtuple() returns a class, not a list:

py> from collections import namedtuple
py> names = ['A', 'B', 'C']
py> namedtuple('lst', names)
<class '__main__.lst'>

The way namedtuple() is intended to be used is like this:


py> from collections import namedtuple
py> names = ['A', 'B', 'C']
py> Record = namedtuple('Record', names)
py> instance = Record(10, 20, 30)
py> print(instance)
Record(A=10, B=20, C=30)


There is no need to call fget directly to access the individual fields:

py> instance.A
10
py> instance.B
20
py> instance[1]  # indexing works too
20


which is *much* simpler than:

py> Record.A.fget(instance)
10



I think you should be doing something like this:

pathname = 'E:\\Coding projects\\Pycharm\\Moving\\Moving 2017 in.csv'
with open(pathname, 'r') as infile:
    rows = list(csv.reader(infile))
    Record = namedtuple("Record", rows[0])
    for row in rows[1:]:  # skip the first row, the header
        row = Record(row)
        # process this row...
        if row.location == 0:
            ...

[...]
> But I haven't found a way to assign new values to a list element. using
> namedtuple.fieldname. I think a basic problem is that namedtuples have
> the properties of tuples, and you can't assign to an existing tuple
> because they're immutable.

Indeed. Being tuples, you have to create a new one. You can do it with slicing, 
like ordinary tuples, but that's rather clunky:

py> print(instance)
Record(A=10, B=20, C=30)
py> Record(999, *instance[1:])
Record(A=999, B=20, C=30)


The recommended way is with the _replace method:

py> instance._replace(A=999)
Record(A=999, B=20, C=30)
py> instance._replace(A=999, C=888)
Record(A=999, B=20, C=888)


Note that despite the leading underscore, _replace is *not* a private method of 
the class. It is intentionally documented as public. The leading underscore is 
so that it won't clash with any field names.




-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From jussi.piitulainen at helsinki.fi  Sun Jan  8 02:01:08 2017
From: jussi.piitulainen at helsinki.fi (Jussi Piitulainen)
Date: Sun, 08 Jan 2017 09:01:08 +0200
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com> <lf5h95bs6it.fsf@ling.helsinki.fi>
 <029aea48-3f1f-4a99-8a3b-6e8a906cbdfd@googlegroups.com>
 <lf5d1fzs2yx.fsf@ling.helsinki.fi>
 <d1eac55a-6ad8-44b4-ac65-a2a073778d53@googlegroups.com>
 <lf560lq4yh3.fsf@ling.helsinki.fi>
 <CAB_tDZwZf0CyGPf5dG0agJrGa54iB_6EaEeH965uCCFzngo3GA@mail.gmail.com>
 <mailman.333.1483840599.2395.python-list@python.org>
Message-ID: <lf5vatqt4qz.fsf@ling.helsinki.fi>

Pablo Lucena writes:

> How about using the second usage of builtin iter()?
>
> In [92]: iter?
> Docstring:
> iter(iterable) -> iterator
> iter(callable, sentinel) -> iterator

Nice to learn about that. But it has the same problem as
itertools.takewhile:

> In [88]: numbers
> Out[88]: [1, 9, 8, 11, 22, 4, 0, 3, 5, 6]
>
> # create iterator over the numbers to make callable simple
> # you may pre-sort or do w/e as needed of course
> In [89]: numbers_it = iter(numbers)
>
> # callable passed into iter - you may customize this
> # using functools.partial if need to add function arguments
> In [90]: def grab_until():
>     ...:     return next(numbers_it)
>     ...:
>
> # here 0 is the 'sentinel' ('int()' would work as well as you have
> # the iterator produced by iter() here stops as soon as sentinel value
> # is encountered
> In [91]: list(iter(grab_until, 0))
> Out[91]: [1, 9, 8, 11, 22, 4]

You get the same with numbers = [1, 9, 8, 11, 22, 4], where 0 does not
occur. How do you then tell which it was?

I think both itertools.takewhile(-, -) and iter(-, -) should have an
option to include the sentinel in their output. Then they could be used
in situations like this.

[The discussion with Rustom about Haskell's lazy evaluation is not
related to this, as far as I can see, so I just snipped it from here.]


From steve+comp.lang.python at pearwood.info  Sun Jan  8 02:37:06 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 08 Jan 2017 18:37:06 +1100
Subject: Grumpy: Python to Go compiler
Message-ID: <5871ec24$0$11119$c3e8da3@news.astraweb.com>

Grumpy, an experimental project from Google, transpiles Python code into Go,
allowing Python programs to be compiled and run as static binaries using the Go
toolchain.



http://www.infoworld.com/article/3154624/application-development/google-boosts-python-by-turning-it-into-go.html


-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From cmpython at gmail.com  Sun Jan  8 02:44:12 2017
From: cmpython at gmail.com (CM)
Date: Sat, 7 Jan 2017 23:44:12 -0800 (PST)
Subject: Can't match str/unicode
In-Reply-To: <5871d987$0$11114$c3e8da3@news.astraweb.com>
References: <821e460c-1bf1-4062-9984-03ec1e110fe1@googlegroups.com>
 <58718ecd$0$1611$c3e8da3$5496439d@news.astraweb.com>
 <44e508f2-6c8d-41f8-bc2f-eaeda2a35e3a@googlegroups.com>
 <5871d987$0$11114$c3e8da3@news.astraweb.com>
Message-ID: <247a4ce0-9cf3-4620-9a57-bf7e2e17a1e6@googlegroups.com>

On Sunday, January 8, 2017 at 1:17:56 AM UTC-5, Steven D'Aprano wrote:
> On Sunday 08 January 2017 15:33, CM wrote:
> 
> > On Saturday, January 7, 2017 at 7:59:01 PM UTC-5, Steve D'Aprano wrote:
> [...]
> >> Start by printing repr(candidate_text) and see what you really have.
> > 
> > Yes, that did it. The repr of that one was, in fact:
> > 
> > u'match /r'
> 
> Are you sure it is a forward-slash /r rather than backslash \r?

No, you're right, it was a backslash \r. Should have pasted it. Good catch.


From no.email at nospam.invalid  Sun Jan  8 04:49:39 2017
From: no.email at nospam.invalid (Paul Rubin)
Date: Sun, 08 Jan 2017 01:49:39 -0800
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com> <lf5h95bs6it.fsf@ling.helsinki.fi>
 <87a8b22ozh.fsf@nightsong.com> <lf5zij2t79f.fsf@ling.helsinki.fi>
Message-ID: <8760lp3mq4.fsf@nightsong.com>

Jussi Piitulainen <jussi.piitulainen at helsinki.fi> writes:
> That would return 0 even when there is no 0 in xs at all.

Doesn't look that way to me:

    >>> minabs([5,3,1,2,4])
    1


From python at deborahswanson.net  Sun Jan  8 04:53:00 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sun, 8 Jan 2017 01:53:00 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <5871df6c$0$1536$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <000401d26994$ffd151b0$27b23dae@sambora>

Steven D'Aprano wrote, on January 07, 2017 10:43 PM
> 
> On Sunday 08 January 2017 16:39, Deborah Swanson wrote:
> 
> > What I've done so far:
> > 
> > with open('E:\\Coding projects\\Pycharm\\Moving\\Moving 
> 2017 in.csv',
> > 'r') as infile:
> >     ls = list(csv.reader(infile))
> >     lst = namedtuple('lst', ls[0])
> > 
> > where 'ls[0]' is the header row of the csv, and it works perfectly 
> > well. 'lst' is a namedtuple instance with each of the 
> column titles as 
> > field names.
> 
> Are you sure? namedtuple() returns a class, not a list:

Yes. 'ls' is defined as 'list(csv.reader(infile))', so ls[0] is the
first row from the csv, the header row. 'lst' is the namedtuple.

Perhaps what's puzzling you is that the way I've written it, the list of
data and the namedtuple are disjoint, and that's the problem.

> py> from collections import namedtuple
> py> names = ['A', 'B', 'C']
> py> namedtuple('lst', names)
> <class '__main__.lst'>
> 
> The way namedtuple() is intended to be used is like this:
> 
> 
> py> from collections import namedtuple
> py> names = ['A', 'B', 'C']
> py> Record = namedtuple('Record', names)
> py> instance = Record(10, 20, 30)
> py> print(instance)
> Record(A=10, B=20, C=30)
> 
> 
> There is no need to call fget directly to access the 
> individual fields:
> 
> py> instance.A
> 10
> py> instance.B
> 20
> py> instance[1]  # indexing works too
> 20
> 
> 
> which is *much* simpler than:
> 
> py> Record.A.fget(instance)
> 10
 
I don't disagree with anything you've said and shown here. But I want to
use the 'instance.A' as a subscript for the list 'ls', and the only way
to do that is with .fget(). Believe me, I tried every possible way to
use instance.A or instance[1] and no way could I get ls[instance.A]. 

The problem I'm having here is one of linkage between the named tuple
for the column titles and the list that holds the data in the columns.

> I think you should be doing something like this:
> 
> pathname = 'E:\\Coding projects\\Pycharm\\Moving\\Moving 2017 
> in.csv' with open(pathname, 'r') as infile:
>     rows = list(csv.reader(infile))
>     Record = namedtuple("Record", rows[0])
>     for row in rows[1:]:  # skip the first row, the header
>         row = Record(row)
>         # process this row...
>         if row.location == 0:
>             ...

Now here you have something I didn't think of: 'row = Record(row)' in a
loop through the rows. 

> [...]
> > But I haven't found a way to assign new values to a list element. 
> > using namedtuple.fieldname. I think a basic problem is that 
> > namedtuples have the properties of tuples, and you can't assign to
an 
> > existing tuple because they're immutable.
> 
> Indeed. Being tuples, you have to create a new one. You can 
> do it with slicing, 
> like ordinary tuples, but that's rather clunky:
> 
> py> print(instance)
> Record(A=10, B=20, C=30)
> py> Record(999, *instance[1:])
> Record(A=999, B=20, C=30)

Very clunky. I don't like modifying standard tuples with slicing, and
this is even worse.

> The recommended way is with the _replace method:
> 
> py> instance._replace(A=999)
> Record(A=999, B=20, C=30)
> py> instance._replace(A=999, C=888)
> Record(A=999, B=20, C=888)
> 
> 
> Note that despite the leading underscore, _replace is *not* a 
> private method of 
> the class. It is intentionally documented as public. The 
> leading underscore is 
> so that it won't clash with any field names.
> 
> 
> 
> 
> -- 
> Steven
> "Ever since I learned about confirmation bias, I've been seeing 
> it everywhere." - Jon Ronson

I will have to work with this. It's entirely possible it will do what I
want it to do. The key problem I was having was getting a linkage
between the namedtuple and the list of data from the csv.

I want to implement a suggestion I got to use a namedtuple made from the
header row as subscripts for elements in the list of data, and the
example given in the docs: 

EmployeeRecord = namedtuple('EmployeeRecord', 'name, age, title,
department, paygrade')

import csv
for emp in map(EmployeeRecord._make, csv.reader(open("employees.csv",
"rb"))):
    print(emp.name, emp.title)

assumes the field names will be hardcoded. Reading the csv into a list
and then trying to use the namedtuple made from the header row as
subscripts is how I ended up resorting to 'Record.A.fget(instance)' to
read values, and wasn't able to assign them. 

But assigning the rows of data into namedtuple instances with: 

Record = namedtuple("Record", rows[0])
for row in rows[1:]: 
    row = Record(row)

does look like the linkage I need and wasn't finding the way I was doing
it. If 'Record(row)' is the list data and the columns are the same as
defined in 'namedtuple("Record", rows[0])', it really should work. And I
didn't get it that _replace could be used to assign new values to
namedtuples (duh. Pretty clear now that I reread it, and all the row
data is in namedtuple instances.) 

The big question is whether the namedtuple instances can be used as
something recognizable as field name subscripts, but that's something
I'll just have to try and see what it looks like. The goal is that
they'll look like row.Description, row.Location, etc., and I think they
will.

Thanks Steven. I know stuff that I've already learned and used enough
that I'm familiar with it pretty well, but I'm a new enough python coder
that I still have to thrash around with something new before I
understand it. I hope I get to a point where I'll be more systematic in
learning complex new things without a professor to tell me how to do it,
but that hasn't quite happened yet.

Deborah



From no.email at nospam.invalid  Sun Jan  8 05:02:02 2017
From: no.email at nospam.invalid (Paul Rubin)
Date: Sun, 08 Jan 2017 02:02:02 -0800
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com> <lf5h95bs6it.fsf@ling.helsinki.fi>
 <87a8b22ozh.fsf@nightsong.com> <lf5zij2t79f.fsf@ling.helsinki.fi>
 <8760lp3mq4.fsf@nightsong.com>
Message-ID: <871swd3m5h.fsf@nightsong.com>

Paul Rubin <no.email at nospam.invalid> writes:
> Doesn't look that way to me:
>     >>> minabs([5,3,1,2,4])
>     1

There's a different problem though:

    >>> minabs([1,2,3,0])
    1

I think Python's version of iterators is actually buggy and at least the
first element of the rest of the sequence should be preserved.  There
are ways to fake it but they're too messy for something like this.  It
should be the default and might have been a good change for Python 3.

    def minabs2(xs):
        def z():
            for x in xs:
                yield x
                if x==0: break
        return min((abs(x),x) for x in z())[1]


seems to work, but is ugly.  Maybe there's something better.


From no.email at nospam.invalid  Sun Jan  8 05:04:30 2017
From: no.email at nospam.invalid (Paul Rubin)
Date: Sun, 08 Jan 2017 02:04:30 -0800
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com> <lf5h95bs6it.fsf@ling.helsinki.fi>
 <87a8b22ozh.fsf@nightsong.com> <lf5zij2t79f.fsf@ling.helsinki.fi>
 <8760lp3mq4.fsf@nightsong.com> <871swd3m5h.fsf@nightsong.com>
Message-ID: <87wpe527gx.fsf@nightsong.com>

Paul Rubin <no.email at nospam.invalid> writes:
> seems to work, but is ugly.  Maybe there's something better.

    def minabs2(xs):
        def z():
            for x in xs:
                yield abs(x), x
                if x==0: break
        return min(z())[1]

is the same thing but a little bit nicer.


From __peter__ at web.de  Sun Jan  8 06:01:23 2017
From: __peter__ at web.de (Peter Otten)
Date: Sun, 08 Jan 2017 12:01:23 +0100
Subject: Using namedtuples field names for column indices in a list of
 lists
References: <5871df6c$0$1536$c3e8da3$5496439d@news.astraweb.com>
 <000401d26994$ffd151b0$27b23dae@sambora>
Message-ID: <o4t65v$4on$1@blaine.gmane.org>

Deborah Swanson wrote:

> to do that is with .fget(). Believe me, I tried every possible way to
> use instance.A or instance[1] and no way could I get ls[instance.A].

Sorry, no.

To get a list of namedtuple instances use:

rows = csv.reader(infile)
Record = namedtuple("Record", next(rows))
records = [Record._make(row) for row in rows]

If you want a column from a list of records you need to extract it manually:

columnA = [record.A for record in records]




From __peter__ at web.de  Sun Jan  8 06:24:04 2017
From: __peter__ at web.de (Peter Otten)
Date: Sun, 08 Jan 2017 12:24:04 +0100
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com> <lf5h95bs6it.fsf@ling.helsinki.fi>
 <87a8b22ozh.fsf@nightsong.com> <lf5zij2t79f.fsf@ling.helsinki.fi>
 <8760lp3mq4.fsf@nightsong.com> <871swd3m5h.fsf@nightsong.com>
 <87wpe527gx.fsf@nightsong.com>
Message-ID: <o4t7gg$c2i$1@blaine.gmane.org>

Paul Rubin wrote:

> Paul Rubin <no.email at nospam.invalid> writes:
>> seems to work, but is ugly.  Maybe there's something better.
> 
>     def minabs2(xs):
>         def z():
>             for x in xs:
>                 yield abs(x), x
>                 if x==0: break
>         return min(z())[1]
> 
> is the same thing but a little bit nicer.

Yes, that's another variant of the decorate/undecorate approach combined 
with Wolfgang's local take_until(). The generalized form that cannot rely on 
the sequence items being orderable would be

firstitem = operator.itemgetter(0)


def stopmin_paul(items, *, key, stop):
    def take_until():
        for item in items:
            k = key(item)
            yield k, item
            if k <= stop:
                break
    return min(take_until(), key=firstitem)[1]




From python at deborahswanson.net  Sun Jan  8 06:54:36 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sun, 8 Jan 2017 03:54:36 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <o4t65v$4on$1@blaine.gmane.org>
Message-ID: <000c01d269a5$fc654020$27b23dae@sambora>

Peter Otten wrote, on January 08, 2017 3:01 AM
> 
> Deborah Swanson wrote:
> 
> > to do that is with .fget(). Believe me, I tried every > possible way
to 
> > use instance.A or instance[1] and no way could I get ls[instance.A].
> 
> Sorry, no.

I quite agree, I was describing the dead end I was in from peeling the
list of data and the namedtuple from the header row off the csv
separately. That was quite obviously the wrong path to take, but I
didn't know what a good way would be.

> To get a list of namedtuple instances use:
> 
> rows = csv.reader(infile)
> Record = namedtuple("Record", next(rows))
> records = [Record._make(row) for row in rows]

This is slightly different from Steven's suggestion, and it makes a
block of records that I think would be iterable. At any rate all the
data from the csv would belong to a single data structure, and that
seems inherently a good thing.

	a = records[i].A , for example

And I think that this would produce recognizable field names in my code
(which was the original goal) if the following works:

records[0] is the header row == ('Description', 'Location', etc.)

If I can use records[i].Location for the Location column data in row
'i', then I've got my recognizable-field-name variables.  

> If you want a column from a list of records you need to 
> extract it manually:
> 
> columnA = [record.A for record in records]

This is very neat. Something like a list comprehension for named tuples?

Thanks Peter, I'll try it all tomorrow and see how it goes.

PS. I haven't forgotten your defaultdict suggestion, I'm just taking the
suggestions I got in the "Cleaning up Conditionals" thread one at a
time, and I will get to defaultdict. Then I'll look at all of them and
see what final version of the code will work best with all the factors
to consider. 



From jussi.piitulainen at helsinki.fi  Sun Jan  8 08:14:03 2017
From: jussi.piitulainen at helsinki.fi (Jussi Piitulainen)
Date: Sun, 08 Jan 2017 15:14:03 +0200
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com> <lf5h95bs6it.fsf@ling.helsinki.fi>
 <87a8b22ozh.fsf@nightsong.com> <lf5zij2t79f.fsf@ling.helsinki.fi>
 <8760lp3mq4.fsf@nightsong.com>
Message-ID: <lf5mvf14rtw.fsf@ling.helsinki.fi>

Paul Rubin writes:

> Jussi Piitulainen writes:
>> That would return 0 even when there is no 0 in xs at all.
>
> Doesn't look that way to me:
>
>     >>> minabs([5,3,1,2,4])
>     1

Sorry about that. I honestly meant to say it would return 1 even when
there was a single 0 at the very end. Somehow I got seriously confused.

You noticed the actual problem yourself.


From jussi.piitulainen at helsinki.fi  Sun Jan  8 08:16:16 2017
From: jussi.piitulainen at helsinki.fi (Jussi Piitulainen)
Date: Sun, 08 Jan 2017 15:16:16 +0200
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com> <lf5h95bs6it.fsf@ling.helsinki.fi>
 <87a8b22ozh.fsf@nightsong.com> <lf5zij2t79f.fsf@ling.helsinki.fi>
 <8760lp3mq4.fsf@nightsong.com> <871swd3m5h.fsf@nightsong.com>
Message-ID: <lf5inpp4rq7.fsf@ling.helsinki.fi>

Paul Rubin writes:

> I think Python's version of iterators is actually buggy and at least
> the first element of the rest of the sequence should be preserved.
> There are ways to fake it but they're too messy for something like
> this.  It should be the default and might have been a good change for
> Python 3.

It could still be added as an option, to both takewhile and iter(_, _).


From __peter__ at web.de  Sun Jan  8 08:20:51 2017
From: __peter__ at web.de (Peter Otten)
Date: Sun, 08 Jan 2017 14:20:51 +0100
Subject: Using namedtuples field names for column indices in a list of
 lists
References: <o4t65v$4on$1@blaine.gmane.org>
 <000c01d269a5$fc654020$27b23dae@sambora>
Message-ID: <o4tebf$al7$1@blaine.gmane.org>

Deborah Swanson wrote:

> Peter Otten wrote, on January 08, 2017 3:01 AM
>> 
>> Deborah Swanson wrote:
>> 
>> > to do that is with .fget(). Believe me, I tried every > possible way
> to
>> > use instance.A or instance[1] and no way could I get ls[instance.A].
>> 
>> Sorry, no.
> 
> I quite agree, I was describing the dead end I was in from peeling the
> list of data and the namedtuple from the header row off the csv
> separately. That was quite obviously the wrong path to take, but I
> didn't know what a good way would be.
> 
>> To get a list of namedtuple instances use:
>> 
>> rows = csv.reader(infile)
>> Record = namedtuple("Record", next(rows))
>> records = [Record._make(row) for row in rows]
> 
> This is slightly different from Steven's suggestion, and it makes a
> block of records that I think would be iterable. At any rate all the
> data from the csv would belong to a single data structure, and that
> seems inherently a good thing.
> 
> a = records[i].A , for example
> 
> And I think that this would produce recognizable field names in my code
> (which was the original goal) if the following works:
> 
> records[0] is the header row == ('Description', 'Location', etc.)

Personally I would recommend against mixing data (an actual location) and 
metadata (the column name,"Location"), but if you wish my code can be 
adapted as follows:

infile = open("dictreader_demo.csv")
rows = csv.reader(infile)
fieldnames = next(rows)
Record = namedtuple("Record", fieldnames)
records = [Record._make(fieldnames)]
records.extend(Record._make(row) for row in rows)

If you want a lot of flexibility without doing the legwork yourself you 
might also have a look at pandas. Example session:

$ cat places.csv
Location,Description,Size
here,something,17
there,something else,10
$ python3
Python 3.4.3 (default, Nov 17 2016, 01:08:31) 
[GCC 4.8.4] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import pandas
>>> places = pandas.read_csv("places.csv")
>>> places
  Location     Description  Size
0     here       something    17
1    there  something else    10

[2 rows x 3 columns]
>>> places.Location
0     here
1    there
Name: Location, dtype: object
>>> places.sort(columns="Size")
  Location     Description  Size
1    there  something else    10
0     here       something    17

[2 rows x 3 columns]
>>> places.Size.mean()
13.5

Be aware that there is a learning curve...
 
> If I can use records[i].Location for the Location column data in row
> 'i', then I've got my recognizable-field-name variables.
> 
>> If you want a column from a list of records you need to
>> extract it manually:
>> 
>> columnA = [record.A for record in records]
> 
> This is very neat. Something like a list comprehension for named tuples?
> 
> Thanks Peter, I'll try it all tomorrow and see how it goes.
> 
> PS. I haven't forgotten your defaultdict suggestion, I'm just taking the
> suggestions I got in the "Cleaning up Conditionals" thread one at a
> time, and I will get to defaultdict. Then I'll look at all of them and
> see what final version of the code will work best with all the factors
> to consider.




From python at deborahswanson.net  Sun Jan  8 08:53:15 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sun, 8 Jan 2017 05:53:15 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <o4tebf$al7$1@blaine.gmane.org>
Message-ID: <002401d269b6$8fb73a80$27b23dae@sambora>

Peter Otten wrote, on January 08, 2017 5:21 AM
> 
> Deborah Swanson wrote:
> 
> > Peter Otten wrote, on January 08, 2017 3:01 AM
> >> 
> >> Deborah Swanson wrote:
> >> 
> >> > to do that is with .fget(). Believe me, I tried every > possible 
> >> > way
> > to
> >> > use instance.A or instance[1] and no way could I get 
> >> > ls[instance.A].
> >> 
> >> Sorry, no.
> > 
> > I quite agree, I was describing the dead end I was in from 
> peeling the 
> > list of data and the namedtuple from the header row off the csv 
> > separately. That was quite obviously the wrong path to take, but I 
> > didn't know what a good way would be.
> > 
> >> To get a list of namedtuple instances use:
> >> 
> >> rows = csv.reader(infile)
> >> Record = namedtuple("Record", next(rows))
> >> records = [Record._make(row) for row in rows]
> > 
> > This is slightly different from Steven's suggestion, and it makes a 
> > block of records that I think would be iterable. At any 
> rate all the 
> > data from the csv would belong to a single data structure, and that 
> > seems inherently a good thing.
> > 
> > a = records[i].A , for example
> > 
> > And I think that this would produce recognizable field names in my 
> > code (which was the original goal) if the following works:
> > 
> > records[0] is the header row == ('Description', 'Location', etc.)
> 
> Personally I would recommend against mixing data (an actual 
> location) and 
> metadata (the column name,"Location"), but if you wish my code can be 
> adapted as follows:
> 
> infile = open("dictreader_demo.csv")
> rows = csv.reader(infile)
> fieldnames = next(rows)
> Record = namedtuple("Record", fieldnames)
> records = [Record._make(fieldnames)]
> records.extend(Record._make(row) for row in rows)

Peter, this looks really good, and yes, I didn't feel so good about 
records[i].Location either, but it was the only way I could see to get
the recognizable variable names I want. By extending records from a
namedtuple of field names, I think it can be done cleanly. I'll try it
and see.

> If you want a lot of flexibility without doing the legwork 
> yourself you 
> might also have a look at pandas. Example session:
> 
> $ cat places.csv
> Location,Description,Size
> here,something,17
> there,something else,10
> $ python3
> Python 3.4.3 (default, Nov 17 2016, 01:08:31) 
> [GCC 4.8.4] on linux
> Type "help", "copyright", "credits" or "license" for more information.
> >>> import pandas
> >>> places = pandas.read_csv("places.csv")
> >>> places
>   Location     Description  Size
> 0     here       something    17
> 1    there  something else    10
> 
> [2 rows x 3 columns]
> >>> places.Location
> 0     here
> 1    there
> Name: Location, dtype: object
> >>> places.sort(columns="Size")
>   Location     Description  Size
> 1    there  something else    10
> 0     here       something    17
> 
> [2 rows x 3 columns]
> >>> places.Size.mean()
> 13.5
> 
> Be aware that there is a learning curve...

Yes, and I'm sure the learning curve is steep. I watched a webinar on
pandas about a year ago, not to actually learn it, but just to take in
the big picture and see something people were really accomplishing with
python.  I won't take this on any time right away, but I'll definitely
keep it and work with it sometime. Maybe as just an intro to pandas,
using my data from the real estate project.


> > If I can use records[i].Location for the Location column 
> data in row 
> > 'i', then I've got my recognizable-field-name variables.
> > 
> >> If you want a column from a list of records you need to extract it 
> >> manually:
> >> 
> >> columnA = [record.A for record in records]
> > 
> > This is very neat. Something like a list comprehension for named 
> > tuples?
> > 
> > Thanks Peter, I'll try it all tomorrow and see how it goes.
> > 
> > PS. I haven't forgotten your defaultdict suggestion, I'm 
> just taking 
> > the suggestions I got in the "Cleaning up Conditionals" 
> thread one at 
> > a time, and I will get to defaultdict. Then I'll look at 
> all of them 
> > and see what final version of the code will work best with all the 
> > factors to consider.



From paul.nospam at rudin.co.uk  Sun Jan  8 09:48:41 2017
From: paul.nospam at rudin.co.uk (Paul Rudin)
Date: Sun, 08 Jan 2017 14:48:41 +0000
Subject: Using namedtuples field names for column indices in a list of
 lists
References: <o4t65v$4on$1@blaine.gmane.org>
 <000c01d269a5$fc654020$27b23dae@sambora>
 <mailman.344.1483876458.2395.python-list@python.org>
Message-ID: <87d1fx4ng6.fsf@rudin.co.uk>

"Deborah Swanson" <python at deborahswanson.net> writes:

> Peter Otten wrote, on January 08, 2017 3:01 AM
>> 
>> columnA = [record.A for record in records]
>
> This is very neat. Something like a list comprehension for named tuples?

Not something like - this *is* a list comprehension - it creates a list
of named tuples.

The thing you iterate over within the comprehension can be any
iterator. (Of course you're going to run into problems if you try to
construct a list from an infinite iterator.)


From no.email at nospam.invalid  Sun Jan  8 14:08:43 2017
From: no.email at nospam.invalid (Paul Rubin)
Date: Sun, 08 Jan 2017 11:08:43 -0800
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com> <lf5h95bs6it.fsf@ling.helsinki.fi>
 <87a8b22ozh.fsf@nightsong.com> <lf5zij2t79f.fsf@ling.helsinki.fi>
 <8760lp3mq4.fsf@nightsong.com> <871swd3m5h.fsf@nightsong.com>
 <87wpe527gx.fsf@nightsong.com> <o4t7gg$c2i$1@blaine.gmane.org>
 <mailman.343.1483874674.2395.python-list@python.org>
Message-ID: <87lgul1i9w.fsf@nightsong.com>

Peter Otten <__peter__ at web.de> writes:
>     return min(take_until(), key=firstitem)[1]

Actually, key=abs should work.  I realized that after posting.


From no.email at nospam.invalid  Sun Jan  8 14:10:23 2017
From: no.email at nospam.invalid (Paul Rubin)
Date: Sun, 08 Jan 2017 11:10:23 -0800
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <87eg0f3b72.fsf@nightsong.com> <lf5h95bs6it.fsf@ling.helsinki.fi>
 <87a8b22ozh.fsf@nightsong.com> <lf5zij2t79f.fsf@ling.helsinki.fi>
 <8760lp3mq4.fsf@nightsong.com> <871swd3m5h.fsf@nightsong.com>
 <lf5inpp4rq7.fsf@ling.helsinki.fi>
Message-ID: <87h9591i74.fsf@nightsong.com>

Jussi Piitulainen <jussi.piitulainen at helsinki.fi> writes:
> It could still be added as an option, to both takewhile and iter(_, _).

That's too messy, it really should be pervasive in iterators.


From python at deborahswanson.net  Sun Jan  8 15:22:52 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sun, 8 Jan 2017 12:22:52 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <87d1fx4ng6.fsf@rudin.co.uk>
Message-ID: <005d01d269ec$fdb52070$27b23dae@sambora>

Paul Rudin wrote, on January 08, 2017 6:49 AM
> 
> "Deborah Swanson" <python at deborahswanson.net> writes:
> 
> > Peter Otten wrote, on January 08, 2017 3:01 AM
> >> 
> >> columnA = [record.A for record in records]
> >
> > This is very neat. Something like a list comprehension for named 
> > tuples?
> 
> Not something like - this *is* a list comprehension - it 
> creates a list of named tuples.
> 
> The thing you iterate over within the comprehension can be 
> any iterator. (Of course you're going to run into problems if 
> you try to construct a list from an infinite iterator.)

Thanks Paul. I've been meaning to spend some time getting to thoroughly
know list comprehensions for awhile now, but I keep running into so many
new things I just haven't gotten to it. I thought it looked like one,
but I hedged my wording because I wasn't sure.  Infinite iterators
definitely sound like something to remember!



From hpj at urpla.net  Sun Jan  8 18:18:38 2017
From: hpj at urpla.net (Hans-Peter Jansen)
Date: Mon, 09 Jan 2017 00:18:38 +0100
Subject: Using sudo with pip3?
In-Reply-To: <CAO6+pg+28J9VEPNc-pCHmBjXT2z9ja4frjZ2YW7tBJQgpjbKHQ@mail.gmail.com>
References: <CAO6+pg+v9B2dTavcAHdm7MLUzqHQnH2BiC9t4ib6X1B3MOAE-g@mail.gmail.com>
 <o4s5j9$ntg$1@blaine.gmane.org>
 <CAO6+pg+28J9VEPNc-pCHmBjXT2z9ja4frjZ2YW7tBJQgpjbKHQ@mail.gmail.com>
Message-ID: <8295323.khLXTiFXdt@xrated>

On Samstag, 7. Januar 2017 19:07:55 Clint Moyer wrote:
> I would lightly advise against, assuming both Pip and your package
> manager are trying to accomplish nearly the same thing. Stick with
> updating through the repo.
> 
> If you find that the version your OS provides is out-of-date compared
> to what's on PyPi or Github, then you might want to remove from your
> OS and re-install through Pip, for those discrete cases. That's the
> platform agnostic route.

Or take the ninja way, I do:

Build all packages, you want (updated) for your distribution:

https://build.opensuse.org/project/monitor/home:frispete:python
https://build.opensuse.org/project/monitor/home:frispete:python3

The red labels are reminders...

SCR,
Pete


From python at deborahswanson.net  Sun Jan  8 19:18:28 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sun, 8 Jan 2017 16:18:28 -0800
Subject: Grumpy: Python to Go compiler
In-Reply-To: <5871ec24$0$11119$c3e8da3@news.astraweb.com>
Message-ID: <000e01d26a0d$e75d3490$27b23dae@sambora>

Steven D'Aprano wrote, on January 07, 2017 11:37 PM
> 
> Grumpy, an experimental project from Google, transpiles 
> Python code into Go, allowing Python programs to be compiled 
> and run as static binaries using the Go toolchain.
> 
> 
> 
http://www.infoworld.com/article/3154624/application-development/google-
boosts-python-by-turning-it-into-go.html
>
>
>-- 
>Steven
>"Ever since I learned about confirmation bias, I've been seeing 
>it everywhere." - Jon Ronson

Interesting online resource, if you can stomach contact with Google.
I'll spare you the diatribe of all my beefs with Google (haha, unless
you ask). But this is a potentially useful tool to know about.



From tonycamgar at gmail.com  Sun Jan  8 19:45:29 2017
From: tonycamgar at gmail.com (Antonio Caminero Garcia)
Date: Sun, 8 Jan 2017 16:45:29 -0800 (PST)
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
In-Reply-To: <mailman.285.1483711463.2395.python-list@python.org>
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
Message-ID: <725de1f8-42f4-4cef-9ca3-58a2c7477576@googlegroups.com>

On Friday, January 6, 2017 at 6:04:33 AM UTC-8, Peter Otten wrote:
> Example: you are looking for the minimum absolute value in a series of 
> integers. As soon as you encounter the first 0 it's unnecessary extra work 
> to check the remaining values, but the builtin min() will continue.
> 
> The solution is a minimum function that allows the user to specify a stop 
> value:
> 
> >>> from itertools import count, chain
> >>> stopmin(chain(reversed(range(10)), count()), key=abs, stop=0)
> 0
> 
> How would you implement stopmin()?
> 
> Currently I raise an exception in the key function:
> 
> class Stop(Exception):
>     pass
> 
> def stopmin(items, key, stop):
>     """
>     >>> def g():
>     ...     for i in reversed(range(10)):
>     ...         print(10*i)
>     ...         yield str(i)
>     >>> stopmin(g(), key=int, stop=5)
>     90
>     80
>     70
>     60
>     50
>     '5'
>     """
>     def key2(value):
>         result = key(value)
>         if result <= stop:
>             raise Stop(value)
>         return result
>     try:
>         return min(items, key=key2)
>     except Stop as stop:
>         return stop.args[0]

This is the simplest version I could come up with. I also like the classic 100% imperative, but it seems that is not trendy between the solutions given :D.

you can test it here https://repl.it/FD5A/0
source code:

from itertools import accumulate

# stopmin calculates the greatest lower bound (infimum). 
# https://upload.wikimedia.org/wikipedia/commons/0/0a/Infimum_illustration.svg 

def takeuntil(pred, seq):
  for item in seq:
    yield item
    if not pred(item):
      break

def stopmin(seq, stop=0):
  drop_ltstop = (item for item in seq if item >= stop)
  min_gen = (min_ for min_ in accumulate(drop_ltstop, func=min))
  return list(takeuntil(lambda x: x!= stop, min_gen))[-1]

seq = [1, 4, 7, -8, 0, 7, -8, 9] # 0 just until zero is generated
seq = [1, 4, 7, -8, 7, -8, 9] # 1 the entire sequence is generated

print(stopmin(seq, stop=0))


From info at tundraware.com  Sun Jan  8 19:49:10 2017
From: info at tundraware.com (Tim Daneliuk)
Date: Sun, 8 Jan 2017 18:49:10 -0600
Subject: Grumpy: Python to Go compiler
In-Reply-To: <mailman.360.1483921113.2395.python-list@python.org>
References: <5871ec24$0$11119$c3e8da3@news.astraweb.com>
 <000e01d26a0d$e75d3490$27b23dae@sambora>
 <mailman.360.1483921113.2395.python-list@python.org>
Message-ID: <a91514a6-6460-d17f-10e9-1e5f6c30f19a@tundraware.com>

On 01/08/2017 06:18 PM, Deborah Swanson wrote:
> (haha, unless
> you ask)

C'mon, go for it ... there hasn't been a good rant here in
4 or 5 minutes ...




From steve+comp.lang.python at pearwood.info  Sun Jan  8 22:29:51 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Mon, 09 Jan 2017 14:29:51 +1100
Subject: Using namedtuples field names for column indices in a list of
 lists
References: <5871df6c$0$1536$c3e8da3$5496439d@news.astraweb.com>
 <000401d26994$ffd151b0$27b23dae@sambora>
 <mailman.341.1483869168.2395.python-list@python.org>
Message-ID: <587303b0$0$11102$c3e8da3@news.astraweb.com>

On Sunday 08 January 2017 20:53, Deborah Swanson wrote:

> Steven D'Aprano wrote, on January 07, 2017 10:43 PM
>> 
>> On Sunday 08 January 2017 16:39, Deborah Swanson wrote:
>> 
>> > What I've done so far:
>> > 
>> > with open('E:\\Coding projects\\Pycharm\\Moving\\Moving
>> 2017 in.csv',
>> > 'r') as infile:
>> >     ls = list(csv.reader(infile))
>> >     lst = namedtuple('lst', ls[0])
>> > 
>> > where 'ls[0]' is the header row of the csv, and it works perfectly
>> > well. 'lst' is a namedtuple instance with each of the
>> column titles as
>> > field names.
>> 
>> Are you sure? namedtuple() returns a class, not a list:
> 
> Yes. 'ls' is defined as 'list(csv.reader(infile))', so ls[0] is the
> first row from the csv, the header row. 'lst' is the namedtuple.
> 
> Perhaps what's puzzling you is that the way I've written it, the list of
> data and the namedtuple are disjoint, and that's the problem.

No, I'm pretty sure that's not the case. I don't have access to your CSV file, 
but I can simulate it:

ls = [['Location', 'Date', 'Price'],
      ['here', '1/1/17', '1234'],
      ['there', '1/1/17', '5678'],
      ['everywhere', '1/1/17', '9821']
      ]

from collections import namedtuple
lst = namedtuple('lst', ls[0])

print(type(lst))
print(lst)



If you run that code, you should see:

<class 'type'>
<class '__main__.lst'>


which contradicts your statement:

    'lst' is a namedtuple instance with each of the column 
    titles as field names.


and explains why you had to access the individual property method `fget`: you 
were accessing the *class object* rather than an actual named tuple instance.

The code you gave was:

    lst.Location.fget(l)

where l was not given, but I can guess it was a row of the CSV file, i.e. an 
individual record. So:

- lst was the named tuple class, a subclass of tuple

- lst.Location returns a property object

- lst.Location.fget is the internal fget method of the property object.


I think Peter Otten has the right idea: create a list of records with something 
like this:


Record = namedtuple('Record', ls[0])
data = [Record(*row) for row in ls[1:])


or if you prefer Peter's version:

data = [Record._make(row) for row in ls[1:])


Half the battle is coming up with the right data structures :-)


-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From python at deborahswanson.net  Sun Jan  8 22:33:45 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sun, 8 Jan 2017 19:33:45 -0800
Subject: Grumpy: Python to Go compiler
In-Reply-To: <a91514a6-6460-d17f-10e9-1e5f6c30f19a@tundraware.com>
Message-ID: <001f01d26a29$2ee552f0$27b23dae@sambora>

Tim Daneliuk wrote, on January 08, 2017 4:49 PM
> 
> On 01/08/2017 06:18 PM, Deborah Swanson wrote:
> > (haha, unless
> > you ask)
> 
> C'mon, go for it ... there hasn't been a good rant here in
> 4 or 5 minutes ...

Oh hell. (How do I tell him I was up til 8am this morning, only got a
few hours sleep, and I'm just too pookie now to deliver a decent rant on
all the ways Google is truly evil.  Don't have to, just did.)

Besides, I'm rewriting code this afternoon and really want to see how
much better it is when I'm done.



From steve+comp.lang.python at pearwood.info  Sun Jan  8 22:53:26 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Mon, 09 Jan 2017 14:53:26 +1100
Subject: Temporary variables in list comprehensions
Message-ID: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>

Suppose you have an expensive calculation that gets used two or more times in a 
loop. The obvious way to avoid calculating it twice in an ordinary loop is with 
a temporary variable:

result = []
for x in data:
    tmp = expensive_calculation(x)
    result.append((tmp, tmp+1))


But what if you are using a list comprehension? Alas, list comps don't let you 
have temporary variables, so you have to write this:


[(expensive_calculation(x), expensive_calculation(x) + 1) for x in data]


Or do you? ... no, you don't!


[(tmp, tmp + 1) for x in data for tmp in [expensive_calculation(x)]]


I can't decide whether that's an awesome trick or a horrible hack...


-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From rosuav at gmail.com  Sun Jan  8 23:09:33 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 9 Jan 2017 15:09:33 +1100
Subject: Temporary variables in list comprehensions
In-Reply-To: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmqHLO7q15kCB-bF0LgEbcYmW=42F=38EEdTP9-J4Emg3Q@mail.gmail.com>

On Mon, Jan 9, 2017 at 2:53 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> [(tmp, tmp + 1) for x in data for tmp in [expensive_calculation(x)]]
>
>
> I can't decide whether that's an awesome trick or a horrible hack...

A horrible hack on par with abusing a recursive function's arguments
for private variables. Much better would be to refactor the append
part:

def this_and_one(value):
    return value, value + 1

[this_and_one(expensive_calculation(x)) for x in data]

ChrisA


From steve+comp.lang.python at pearwood.info  Sun Jan  8 23:49:10 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Mon, 09 Jan 2017 15:49:10 +1100
Subject: Temporary variables in list comprehensions
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqHLO7q15kCB-bF0LgEbcYmW=42F=38EEdTP9-J4Emg3Q@mail.gmail.com>
 <mailman.362.1483934982.2395.python-list@python.org>
Message-ID: <58731647$0$11108$c3e8da3@news.astraweb.com>

On Monday 09 January 2017 15:09, Chris Angelico wrote:

> On Mon, Jan 9, 2017 at 2:53 PM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> [(tmp, tmp + 1) for x in data for tmp in [expensive_calculation(x)]]
>>
>>
>> I can't decide whether that's an awesome trick or a horrible hack...
> 
> A horrible hack on par with abusing a recursive function's arguments
> for private variables. 

What's wrong with that? That's a perfectly legitimate technique. I prefer to 
hide it behind a private function rather than expose it in a public interface:

# instead of this
def recursive(arg, _internal=None):
    """Recursive function. Don't supply the _internal argument."""
    ...
    return recursive(arg-1, spam)


# I usually prefer this
def recursive(arg):
    """Recursive function."""
    return _recursive(arg, spam)

def _recursive(arg, internal):
    ...


but that's just polishing the code.



> Much better would be to refactor the append
> part:
> 
> def this_and_one(value):
>     return value, value + 1

I wouldn't call that "much better". Requiring an extra function defeats the 
purpose of using a list comp, and it doesn't scale well for multiple list comps 
each of which needs a different helper function:


def this_and_one(value):
    return value, value + 1

def this_less_one_and_this_plus_one_and_this(value):
    return value - 1, value + 1, value

def this_and_that_or_something(value):
    return value, value.that() or something

def extract_value(value):
    return spam[value] or ham[value] or eggs[value]


and so on. Helper functions are good. Helper functions that are only used 
*once* are a code smell. *LOTS* of helper functions that are only used once are 
a sign that something is horrible, and it might just be your language...



-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From rosuav at gmail.com  Sun Jan  8 23:54:31 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 9 Jan 2017 15:54:31 +1100
Subject: Temporary variables in list comprehensions
In-Reply-To: <58731647$0$11108$c3e8da3@news.astraweb.com>
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqHLO7q15kCB-bF0LgEbcYmW=42F=38EEdTP9-J4Emg3Q@mail.gmail.com>
 <mailman.362.1483934982.2395.python-list@python.org>
 <58731647$0$11108$c3e8da3@news.astraweb.com>
Message-ID: <CAPTjJmqV5Z428NvzVMaRiccQvQCR8iMkFy0N1EnQdq62Y0cP4w@mail.gmail.com>

On Mon, Jan 9, 2017 at 3:49 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Helper functions are good. Helper functions that are only used
> *once* are a code smell. *LOTS* of helper functions that are only used once are
> a sign that something is horrible, and it might just be your language...

Agreed, but with a toy example like you posted, it's impossible to say
which is happening :)

ChrisA


From rustompmody at gmail.com  Mon Jan  9 00:51:03 2017
From: rustompmody at gmail.com (Rustom Mody)
Date: Sun, 8 Jan 2017 21:51:03 -0800 (PST)
Subject: Temporary variables in list comprehensions
In-Reply-To: <58731647$0$11108$c3e8da3@news.astraweb.com>
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqHLO7q15kCB-bF0LgEbcYmW=42F=38EEdTP9-J4Emg3Q@mail.gmail.com>
 <mailman.362.1483934982.2395.python-list@python.org>
 <58731647$0$11108$c3e8da3@news.astraweb.com>
Message-ID: <e2b493e1-dfcb-4672-9a20-94edd5401d4e@googlegroups.com>

On Monday, January 9, 2017 at 10:19:31 AM UTC+5:30, Steven D'Aprano wrote:
> On Monday 09 January 2017 15:09, Chris Angelico wrote:
> 
> > On Mon, Jan 9, 2017 at 2:53 PM, Steven D'Aprano wrote:
> >> [(tmp, tmp + 1) for x in data for tmp in [expensive_calculation(x)]]
> >>
> >>
> >> I can't decide whether that's an awesome trick or a horrible hack...
> > 
> > A horrible hack on par with abusing a recursive function's arguments
> > for private variables. 
> 
> What's wrong with that? That's a perfectly legitimate technique. I prefer to 
> hide it behind a private function rather than expose it in a public interface:
> 
> # instead of this
> def recursive(arg, _internal=None):
>     """Recursive function. Don't supply the _internal argument."""
>     ...
>     return recursive(arg-1, spam)
> 
> 
> # I usually prefer this
> def recursive(arg):
>     """Recursive function."""
>     return _recursive(arg, spam)
> 
> def _recursive(arg, internal):
>     ...
> 
> 
> but that's just polishing the code.
> 
> 
> 
> > Much better would be to refactor the append
> > part:
> > 
> > def this_and_one(value):
> >     return value, value + 1
> 
> I wouldn't call that "much better". Requiring an extra function defeats the 
> purpose of using a list comp, and it doesn't scale well for multiple list comps 

+1

Id call it (your original) neither an awesome trick nor a horrible hack ? just 
a neat workaround for an obvious lacuna

As for Chris' solution there is a simple test to see whether it's worth it:
Does the function name make sense? If yes then the subexpression refactored-
into-a-function is probably fine. If not the kludgyness shows

[Im assuming the real usage is something else and your question is a highly
sscce-ed version]


From esj at harvee.org  Mon Jan  9 00:57:24 2017
From: esj at harvee.org (Eric S. Johansson)
Date: Mon, 9 Jan 2017 00:57:24 -0500
Subject: Python for WEB-page !?
In-Reply-To: <eba3dc40-05ec-0d17-21c9-0907da4ecaca@gmail.com>
References: <4df49556-ce91-4ca5-8d9e-f505d7f1a1e9@googlegroups.com>
 <eba3dc40-05ec-0d17-21c9-0907da4ecaca@gmail.com>
Message-ID: <0b621aaa-03d0-0e72-f12d-030189e6a3f1@harvee.org>

On 1/5/2017 7:48 PM, Michael Torrie wrote:
> While Python can do that, using a web framework to process HTTP requests
> and generate HTML to display in the browser, I don't believe Python is
> the appropriate language for the task at hand.  Most web sites that do
> interactive formula calculations like you describe do it all in the
> browser using Javascript.  No need to have a web server do all that
> heavy lifting at all.  A simple html file would contain everything you need.
>
> Even if you want to use Python to generate the web page and process
> events, you'll still have to master Javascript at some point to make the
> webpages more interactive.

There are a few implementations of Python that generate code that can
run the browser. I'm currently using brython and its significantly
easier than struggling with JavaScript. It's not perfect by any means,
it has its own quirks and bugs but the developer is very responsive, the
product is getting better every month and I like to see the Python
community give it a bit more love



From python at deborahswanson.net  Mon Jan  9 01:18:35 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sun, 8 Jan 2017 22:18:35 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <5871df6c$0$1536$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <002a01d26a40$35ea89a0$27b23dae@sambora>

Steven D'Aprano wrote, on January 07, 2017 10:43 PM
> 
> On Sunday 08 January 2017 16:39, Deborah Swanson wrote:
> 
> The recommended way is with the _replace method:
> 
> py> instance._replace(A=999)
> Record(A=999, B=20, C=30)
> py> instance._replace(A=999, C=888)
> Record(A=999, B=20, C=888)
> 
> -- 
> Steven
> "Ever since I learned about confirmation bias, I've been seeing 
> it everywhere." - Jon Ronson

instance._replace(A=999) works perfectly, and editting my existing
assignment statements was really easy.  Thanks - a lot.



From python at deborahswanson.net  Mon Jan  9 01:58:34 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sun, 8 Jan 2017 22:58:34 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <o4tebf$al7$1@blaine.gmane.org>
Message-ID: <003301d26a45$cc04a5b0$27b23dae@sambora>

Peter Otten wrote, on January 08, 2017 5:21 AM
> 
> Deborah Swanson wrote:
> 
> > Peter Otten wrote, on January 08, 2017 3:01 AM
>  
> Personally I would recommend against mixing data (an actual location)
and 
> metadata (the column name,"Location"), but if you wish my code can be 
> adapted as follows:
> 
> infile = open("dictreader_demo.csv")
> rows = csv.reader(infile)
> fieldnames = next(rows)
> Record = namedtuple("Record", fieldnames)
> records = [Record._make(fieldnames)]
> records.extend(Record._make(row) for row in rows)

Works like a charm. I stumbled a bit changing all my subscripted
variables to namedtuples and rewriting the inevitable places my code
that didn't work the same. But actually it was fun, especially deleting
all the sections and variables I no longer needed. And it executes
correctly now too - with recognizable fieldnames instead of my quirky
2-letter code subscripts.  All in all a huge win!

I do have two more questions.

1) I have a section that loops through the sorted data, compares two
adjacent rows at a time, and marks one of them for deletion if the rows
are identical.

I'm using 

for i in range(len(records)-1):
    r1 = records[i]
    r2 = records[i+1]
    if r1.xx = r2.xx:
		.
		.
and my question is whether there's a way to work with two adjacent rows
without using subscripts?  

Even better, to get hold of all the records with the same Description as
the current row, compare them all, mark all but the different ones for
deletion, and then resume processing the records after the last one?

2) I'm using mergesort. (I didn't see any way to sort a namedtuple in
the docs.) In the list version of my code I copied and inserted the 2
columns I wanted to sort by into the beginning of the list, and then
deleted them after the list was sorted. But just looking at records, I'm
not so sure that can easily be done. I remember your code to work with
columns of the data:

columnA = [record.A for record in records]

and I can see how that would get me columnA and columnB, but then is
there any better way to insert and delete columns in an existing
namedtuple than slicing? And I don't think you can insert or delete a
whole column while slicing.

Or maybe my entire approach is not the best. I know it's possible to do
keyed sorts, but I haven't actually written or used any. So I just
pulled a mergesort off the shelf and got what I wanted by inserting
copies of those 2 columns at the front, and then deleting them when the
sort was complete. Not exactly elegant, but it works.

Any suggestions would be most welcome. 



From python at deborahswanson.net  Mon Jan  9 02:11:58 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sun, 8 Jan 2017 23:11:58 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <587303b0$0$11102$c3e8da3@news.astraweb.com>
Message-ID: <003901d26a47$ab209ff0$27b23dae@sambora>

Steven D'Aprano wrote, on January 08, 2017 7:30 PM
> 
> On Sunday 08 January 2017 20:53, Deborah Swanson wrote:
> 
> > Steven D'Aprano wrote, on January 07, 2017 10:43 PM
> 
> No, I'm pretty sure that's not the case. I don't have access 
> to your CSV file, 
> but I can simulate it:
> 
> ls = [['Location', 'Date', 'Price'],
>       ['here', '1/1/17', '1234'],
>       ['there', '1/1/17', '5678'],
>       ['everywhere', '1/1/17', '9821']
>       ]
> 
> from collections import namedtuple
> lst = namedtuple('lst', ls[0])
> 
> print(type(lst))
> print(lst)
> 
> 
> 
> If you run that code, you should see:
> 
> <class 'type'>
> <class '__main__.lst'>
> 
> 
> which contradicts your statement:
> 
>     'lst' is a namedtuple instance with each of the column 
>     titles as field names.

Yes, yes. In a careless moment I called a class an instance.

> and explains why you had to access the individual property 
> method `fget`: you 
> were accessing the *class object* rather than an actual named 
> tuple instance.

That code is deleted and long gone now, so I can't look at it in the
debugger, but yes, I'm pretty sure 'fget' is a class member.

> The code you gave was:
> 
>     lst.Location.fget(l)
> 
> where l was not given, but I can guess it was a row of the 
> CSV file, i.e. an 
> individual record. So:
> 
> - lst was the named tuple class, a subclass of tuple
> 
> - lst.Location returns a property object
> 
> - lst.Location.fget is the internal fget method of the 
> property object.

And your point is?  Perhaps I didn't express myself in a way that you
could recognize, but I understood all of that before I wrote to you, and
attempted to convey that understanding to you. Obviously I failed, if
you now think I need a lesson in what's going on here.

> I think Peter Otten has the right idea: create a list of 
> records with something 
> like this:
> 
> 
> Record = namedtuple('Record', ls[0])
> data = [Record(*row) for row in ls[1:])
> 
> 
> or if you prefer Peter's version:
> 
> data = [Record._make(row) for row in ls[1:])
> 
> 
> Half the battle is coming up with the right data structures :-)

Can't and wouldn't disagree with any part of that!

> -- 
> Steven
> "Ever since I learned about confirmation bias, I've been seeing 
> it everywhere." - Jon Ronson



From stephane at wirtel.be  Mon Jan  9 04:54:49 2017
From: stephane at wirtel.be (Stephane Wirtel)
Date: Mon, 9 Jan 2017 10:54:49 +0100
Subject: Python Events in 2017, Need your help.
Message-ID: <20170109095449.v4ual5czl5mc7xxs@sg1>

Dear Community,

For the PythonFOSDEM [1] on 4th and 5th February in Belgium, I would 
like to present some slides with the Python events around the World.  
Based on https://python.org/events, I have noted that there are missing 
events, for example:

* PyCon Otto: Italy
* PyCon UK: United Kingdom
* PyCon CA: Canada
* PyCon Ireland: Ireland
* PyCon France: France

Some of these events are not yet announced and I understand they are in 
the second semester, and thus, they don't know the location and the 
dates, excepted for PyCon Otto (April).

In fact, I have noted that we know some big events in the Python 
community (for example: PyCon US and EuroPython) but do you know the 
others events, maybe the local event, PyCon IE, PyCon UK or PyCon IT.

I like to know where there is a PyCon or a Django Conf or a PyData Event.

In fact, I think we can help the Python Community if we submit all the 
events in https://python.org/events.

This page has been created by the PSF and is maintained by some 
volunteers.

I know this list of events: 

* PyCon Cameroon : 20-23 Jav, Cameroon
* PythonFOSDEM : 4-5 Feb, Belgium
* PyCon Colombia : 10-12 Feb, Colombia
* PyCon Pune : 16-20 Feb, India
* Swiss Python Summit : 17-18 Feb, Switzerland
* IrPyCon : 17-18 Feb, Iran
* PyCon SK : 10-13 Mar, Slovakia
* Django Europe : 3-8 Apr, Italy
* PyCon Otto : 6-9 Apr, Italy
* Python Sudeste : 5-7 Mai, Brazil
* GeoPython : 8-11 May, Switzerland
* PyCon US : 17-26 May, USA
* EuroPython : July, Italy
* PyCon AU : 3-9 Aug, Australia
* PyCon UK : September, United Kingdom
* PyCon CA : November, Canada
* PyCon Ireland : October, Ireland
* PyCon FR : October/November, France

And you ? 

Please, could you check on https://www.python.org/events/ , if you are 
an organizer, please add your event.

If you think there is a missing event, please, send me the info via 
[email](mailto:stephane at wirtel.be) or via my [twitter 
account](https://twitter.com/matrixise) and I will add it on my slides.

I would like to present your event.

Thank you so much for your help.

Stephane Wirtel

[1] https://www.python-fosdem.org

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


From antoon.pardon at rece.vub.ac.be  Mon Jan  9 05:14:19 2017
From: antoon.pardon at rece.vub.ac.be (Antoon Pardon)
Date: Mon, 9 Jan 2017 11:14:19 +0100
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <003301d26a45$cc04a5b0$27b23dae@sambora>
References: <003301d26a45$cc04a5b0$27b23dae@sambora>
Message-ID: <65e73143-fa67-c160-b38c-2d1577872c45@rece.vub.ac.be>

Op 09-01-17 om 07:58 schreef Deborah Swanson:
> Peter Otten wrote, on January 08, 2017 5:21 AM
>> Deborah Swanson wrote:
>>
>>> Peter Otten wrote, on January 08, 2017 3:01 AM
>>  
>> Personally I would recommend against mixing data (an actual location)
> and 
>> metadata (the column name,"Location"), but if you wish my code can be 
>> adapted as follows:
>>
>> infile = open("dictreader_demo.csv")
>> rows = csv.reader(infile)
>> fieldnames = next(rows)
>> Record = namedtuple("Record", fieldnames)
>> records = [Record._make(fieldnames)]
>> records.extend(Record._make(row) for row in rows)
> Works like a charm. I stumbled a bit changing all my subscripted
> variables to namedtuples and rewriting the inevitable places my code
> that didn't work the same. But actually it was fun, especially deleting
> all the sections and variables I no longer needed. And it executes
> correctly now too - with recognizable fieldnames instead of my quirky
> 2-letter code subscripts.  All in all a huge win!
>
> I do have two more questions.
>
> 1) I have a section that loops through the sorted data, compares two
> adjacent rows at a time, and marks one of them for deletion if the rows
> are identical.
>
> I'm using 
>
> for i in range(len(records)-1):
>     r1 = records[i]
>     r2 = records[i+1]
>     if r1.xx = r2.xx:
> 		.
> 		.
> and my question is whether there's a way to work with two adjacent rows
> without using subscripts?  

for r1, r2 in zip(records[i], records[i+1]):
    if r1.xx == r2.xx
        .
        .




From antoon.pardon at rece.vub.ac.be  Mon Jan  9 05:35:18 2017
From: antoon.pardon at rece.vub.ac.be (Antoon Pardon)
Date: Mon, 9 Jan 2017 11:35:18 +0100
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <003301d26a45$cc04a5b0$27b23dae@sambora>
References: <003301d26a45$cc04a5b0$27b23dae@sambora>
Message-ID: <133f4cc5-b56a-fba6-cde9-bb98eb080fac@rece.vub.ac.be>

Op 09-01-17 om 07:58 schreef Deborah Swanson:
> Peter Otten wrote, on January 08, 2017 5:21 AM
>> Deborah Swanson wrote:
>>
>>> Peter Otten wrote, on January 08, 2017 3:01 AM
>>  
>> Personally I would recommend against mixing data (an actual location)
> and 
>> metadata (the column name,"Location"), but if you wish my code can be 
>> adapted as follows:
>>
>> infile = open("dictreader_demo.csv")
>> rows = csv.reader(infile)
>> fieldnames = next(rows)
>> Record = namedtuple("Record", fieldnames)
>> records = [Record._make(fieldnames)]
>> records.extend(Record._make(row) for row in rows)
> Works like a charm. I stumbled a bit changing all my subscripted
> variables to namedtuples and rewriting the inevitable places my code
> that didn't work the same. But actually it was fun, especially deleting
> all the sections and variables I no longer needed. And it executes
> correctly now too - with recognizable fieldnames instead of my quirky
> 2-letter code subscripts.  All in all a huge win!
>
> I do have two more questions.
>
> 1) I have a section that loops through the sorted data, compares two
> adjacent rows at a time, and marks one of them for deletion if the rows
> are identical.
>
> I'm using 
>
> for i in range(len(records)-1):
>     r1 = records[i]
>     r2 = records[i+1]
>     if r1.xx = r2.xx:
> 		.
> 		.
> and my question is whether there's a way to work with two adjacent rows
> without using subscripts?  
>
> Even better, to get hold of all the records with the same Description as
> the current row, compare them all, mark all but the different ones for
> deletion, and then resume processing the records after the last one?

If I understand correctly you want something like:

    records.sort(key = lamda rec: rec.xx)

AKA 

    from operator import attrgetter
    records.sort(key = attrgetter('xx'))

or maybe:

    records.sort(key = lambda rec: (rec.xx,) + tuple(rec))

-- 
Antoon Pardon



From storchaka at gmail.com  Mon Jan  9 05:41:44 2017
From: storchaka at gmail.com (Serhiy Storchaka)
Date: Mon, 9 Jan 2017 12:41:44 +0200
Subject: Temporary variables in list comprehensions
In-Reply-To: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <o4vpd4$nuu$1@blaine.gmane.org>

On 09.01.17 05:53, Steven D'Aprano wrote:
> Suppose you have an expensive calculation that gets used two or more times in a
> loop. The obvious way to avoid calculating it twice in an ordinary loop is with
> a temporary variable:
>
> result = []
> for x in data:
>     tmp = expensive_calculation(x)
>     result.append((tmp, tmp+1))
>
>
> But what if you are using a list comprehension?

result = [(tmp, tmp + 1)
           for tmp in (expensive_calculation(x) for x in data)]

You could also assign an internal generator expression to temporal 
variable for readability if it is long.

gen = (expensive_calculation(x) for x in data)
result = [(tmp, tmp + 1) for tmp in gen]




From no.email at nospam.invalid  Mon Jan  9 05:44:12 2017
From: no.email at nospam.invalid (Paul Rubin)
Date: Mon, 09 Jan 2017 02:44:12 -0800
Subject: Temporary variables in list comprehensions
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <8760lo1pj7.fsf@nightsong.com>

Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:
> [(expensive_calculation(x), expensive_calculation(x) + 1) for x in data]

   def memoize(f):
	cache = {}
	def m(x):
		if x in cache:
			return cache[x]
		a = f(x)
		cache[x] = a
		return a
	return m

   ec = memoize(expensive_calculation)
   ...  [(ec(x), ec(x) + 1) for x in data]

Or can write:

    @memoize
    def expensive_calculation(x): ....

Note the Haskell version of your listcomp would be:

  [(e, e+1) | x <- data_, let e = expensive_calculation x]

Maybe Python could get some version of that.  I've wanted it more than
once.  (I used "data_" because data is a Haskell keyword).


From python at deborahswanson.net  Mon Jan  9 05:45:54 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 9 Jan 2017 02:45:54 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <65e73143-fa67-c160-b38c-2d1577872c45@rece.vub.ac.be>
Message-ID: <005601d26a65$8e01f5e0$27b23dae@sambora>

Antoon Pardon wrote, on January 09, 2017 2:14 AM

> > 1) I have a section that loops through the sorted data, compares two

> > adjacent rows at a time, and marks one of them for deletion if the 
> > rows are identical.
> >
> > I'm using
> >
> > for i in range(len(records)-1):
> >     r1 = records[i]
> >     r2 = records[i+1]
> >     if r1.xx = r2.xx:
> > 		.
> > 		.
> > and my question is whether there's a way to work with two adjacent 
> > rows without using subscripts?
> 
> for r1, r2 in zip(records[i], records[i+1]):
>     if r1.xx == r2.xx
>         .
>         .

Ok, I've seen the zip function before and it might do the job, but here
I think you're suggesting:

for i in range(len(records)-1):
	for r1, r2 in zip(records[i], records[i+1]):
		if r1.xx == r2.xx
			.
			.

The hope was to do the loop without subscripts, and this may or may not
have gotchas because records is a namedtuple:

for r in records(1:):
	.
	.

Deborah



From no.email at nospam.invalid  Mon Jan  9 05:46:44 2017
From: no.email at nospam.invalid (Paul Rubin)
Date: Mon, 09 Jan 2017 02:46:44 -0800
Subject: Temporary variables in list comprehensions
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
 <o4vpd4$nuu$1@blaine.gmane.org>
 <mailman.372.1483958517.2395.python-list@python.org>
Message-ID: <871swc1pez.fsf@nightsong.com>

Serhiy Storchaka <storchaka at gmail.com> writes:
> gen = (expensive_calculation(x) for x in data)
> result = [(tmp, tmp + 1) for tmp in gen]

result = [(tmp, tmp+1) for tmp in map(expensive_calculation, data)]


From python at deborahswanson.net  Mon Jan  9 05:57:48 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 9 Jan 2017 02:57:48 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <133f4cc5-b56a-fba6-cde9-bb98eb080fac@rece.vub.ac.be>
Message-ID: <005701d26a67$37b99290$27b23dae@sambora>

Antoon Pardon wrote, on January 09, 2017 2:35 AM

> If I understand correctly you want something like:
> 
>     records.sort(key = lamda rec: rec.xx)
> 
> AKA 
> 
>     from operator import attrgetter
>     records.sort(key = attrgetter('xx'))
> 
> or maybe:
> 
>     records.sort(key = lambda rec: (rec.xx,) + tuple(rec))
> 
> -- 
> Antoon Pardon

I think you are replying to my question about sorting a namedtuple, in
this case it's called 'records'.

I think your suggestion works for lists and tuples, and probably
dictionaries. But namedtuples doesn't have a sort function.

>>> from collections import namedtuple
>>> dir(namedtuple)
['__annotations__', '__call__', '__class__', '__closure__', '__code__',
'__defaults__', '__delattr__', '__dict__', '__dir__', '__doc__',
'__eq__', '__format__', '__ge__', '__get__', '__getattribute__',
'__globals__', '__gt__', '__hash__', '__init__', '__kwdefaults__',
'__le__', '__lt__', '__module__', '__name__', '__ne__', '__new__',
'__qualname__', '__reduce__', '__reduce_ex__', '__repr__',
'__setattr__', '__sizeof__', '__str__', '__subclasshook__']

so nothing with records.sort will work.  :(

Deborah



From steve+python at pearwood.info  Mon Jan  9 06:39:45 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Mon, 09 Jan 2017 22:39:45 +1100
Subject: Using namedtuples field names for column indices in a list of
 lists
References: <133f4cc5-b56a-fba6-cde9-bb98eb080fac@rece.vub.ac.be>
 <005701d26a67$37b99290$27b23dae@sambora>
 <mailman.374.1483959422.2395.python-list@python.org>
Message-ID: <58737683$0$1606$c3e8da3$5496439d@news.astraweb.com>

On Mon, 9 Jan 2017 09:57 pm, Deborah Swanson wrote:

[...]
> I think you are replying to my question about sorting a namedtuple, in
> this case it's called 'records'.
> 
> I think your suggestion works for lists and tuples, and probably
> dictionaries. But namedtuples doesn't have a sort function.

Tuples in general (whether named or not) represent structs or records, where
the position of the item is significant. It doesn't usually make sense to
sort individual elements of a record or tuple:

Before sorting: Record(name='George', spouse='', position='Accountant')
After sorting:  Record(name='', spouse='Accountant', position='George')


I think what you want to do is sort a list of records, not each record
itself. Or possibly you want to reorder the columns, in which case the
easiest way to do that is by editing the CSV file in LibreOffice or Excel
or another spreadsheet application.

If you have a list of records, call .sort() on the list, not the individual
records. 

But if I am wrong, and you absolutely must sort the fields of each record,
call the sorted() function, which will copy the fields into a list and sort
the list. That is:

alist = sorted(record)





-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From ghasselbring at hotmail.com  Mon Jan  9 06:48:00 2017
From: ghasselbring at hotmail.com (Gretchen Hasselbring)
Date: Mon, 9 Jan 2017 11:48:00 +0000
Subject: Error message IDLE
Message-ID: <HE1PR0602MB28116020D7BA058EAA5B39EAD8640@HE1PR0602MB2811.eurprd06.prod.outlook.com>

Hello

Trying to learn python on a laptop.  Was successful for awhile then...

Had a 'subprocess startup error'

'IDLE's subprocess didn't make connection.  Either IDLE can't start subprocess or personal firewall software is blocking the connection '


Doesn't appear to be firewall and I uninstalled and reinstalled python 3.6.032 bit???

Any advice?
Thanks


Sent from my iPad

From python.list at tim.thechases.com  Mon Jan  9 07:15:31 2017
From: python.list at tim.thechases.com (Tim Chase)
Date: Mon, 9 Jan 2017 06:15:31 -0600
Subject: Temporary variables in list comprehensions
In-Reply-To: <871swc1pez.fsf@nightsong.com>
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
 <o4vpd4$nuu$1@blaine.gmane.org>
 <mailman.372.1483958517.2395.python-list@python.org>
 <871swc1pez.fsf@nightsong.com>
Message-ID: <20170109061531.71e3c795@bigbox.christie.dr>

On 2017-01-09 02:46, Paul Rubin wrote:
> > gen = (expensive_calculation(x) for x in data)
> > result = [(tmp, tmp + 1) for tmp in gen]  
> 
> result = [(tmp, tmp+1) for tmp in map(expensive_calculation, data)]

As charmingly expressive as map() is, the wildly different behavior in
py3 (it's a generator that evaluates lazily) vs py2 (it consumes the
entire iterable in one go) leads me to avoid it in general,
especially when Python gives me list-comprehensions and generators
that can do what I intend explicitly.  E.g., passing in
itertools.count() as an iterable to map() will kill py2 but is
perfectly fine in py3 (a horrible example):

  import itertools as i
  for x in i.takewhile(
      lambda n: n < 100, 
      map(lambda g: g**2, i.count())
      ):
    print(x)

But yes, both ChrisA's pass-it-to-a-function and Serhiy's nested
generate-the-tmp-values-then-operate-on-those are good solutions
depending on how they feel in any particular context.  If I need to
use an "if" clause in the outer generator that tests the resulting
temp values, I use Serhiy's solution:

  [(tmp, tmp + 1)
    for tmp in (
      expensive_calculation(x)
      for x in data
      )
    if tmp > 42
    ]
 
Otherwise, I like the cleanliness of ChrisA's function:

  def fn(x)
    tmp = expensive_calculation(x)
    return x, x + 1
  [fn(x) for x in data]

-tkc






From python at deborahswanson.net  Mon Jan  9 07:25:27 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 9 Jan 2017 04:25:27 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <58737683$0$1606$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <007101d26a73$7601d2e0$27b23dae@sambora>

Steve D'Aprano wrote, on January 09, 2017 3:40 AM
> 
> On Mon, 9 Jan 2017 09:57 pm, Deborah Swanson wrote:
> 
> [...]
> > I think you are replying to my question about sorting a 
> namedtuple, in 
> > this case it's called 'records'.
> > 
> > I think your suggestion works for lists and tuples, and probably 
> > dictionaries. But namedtuples doesn't have a sort function.
> 
> Tuples in general (whether named or not) represent structs or 
> records, where the position of the item is significant. It 
> doesn't usually make sense to sort individual elements of a 
> record or tuple:
> 
> Before sorting: Record(name='George', spouse='', 
> position='Accountant') After sorting:  Record(name='', 
> spouse='Accountant', position='George')
> 
> 
> I think what you want to do is sort a list of records, not 
> each record itself. Or possibly you want to reorder the 
> columns, in which case the easiest way to do that is by 
> editing the CSV file in LibreOffice or Excel or another 
> spreadsheet application.
> If you have a list of records, call .sort() on the list, not 
> the individual records. 
> 

I want to sort a nametuple of records.

I could convert it to a list easy enough, with:

recs = list(records)

and then use the column copying and deleting method I described in my
previous post and use mergesort. This would give me exactly what I had
in my original code, and it would be ok. There's only one step after the
mergesort, and I could do it without the namedtuple, although I'd have
to count column indices for that section, and rewrite them whenever the
columns changed, which was what my original 2-letter codes and the
conversion to namedtuples were both meant to avoid.

So all in all, the best thing would be if there's a way to sort records
as a namedtuple. 


> But if I am wrong, and you absolutely must sort the fields of 
> each record, call the sorted() function, which will copy the 
> fields into a list and sort the list. That is:
> 
> alist = sorted(record)
> 
> -- 
> Steve
> "Cheer up," they said, "things could be worse." So I cheered 
> up, and sure enough, things got worse.

I'm not sure what you mean by sorting the fields of each record. I want
all the rows in records sorted by the Description and Date in each
record.

alist = sorted(record)

looks like it sorts one record, by what? An alphanumeric ordering of all
the fields in record?  That would be beyond useless for my purposes.

It's possible sorted() will work on namedtuples. Stackoverflow has an
example:

from operator import attrgetter
from collections import namedtuple

Person = namedtuple('Person', 'name age score')
seq = [Person(name='nick', age=23, score=100),
       Person(name='bob', age=25, score=200)]
# Sort list by name
sorted(seq, key=attrgetter('name'))
# Sort list by age
sorted(seq, key=attrgetter('age'))

So apparently it's done, and it's a keyed sort too. Although what
they're sorting is a list of namedtuples, which may or may not work on a
single namedtuple made of row (record) namedtuples. I'll definitely try
it tomorrow.

Know any way to convert a list back into a namedtuple? I suppose I could
go through all the steps used at the beginning to make records, but that
seems a waste if there's any way at all to sort the namedtuple without
converting it into a list.

Thanks Steven! Maybe sorted() is my friend here.  (haha, and maybe not.)

Deborah



From rhodri at kynesim.co.uk  Mon Jan  9 07:27:38 2017
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Mon, 9 Jan 2017 12:27:38 +0000
Subject: Clickable hyperlinks
In-Reply-To: <4018729974@f38.n261.z1.binkp.net>
References: <4018729974@f38.n261.z1.binkp.net>
Message-ID: <6cafdb17-0a68-1000-abc0-fd8634fd473d@kynesim.co.uk>

On 05/01/17 02:53, Deborah Swanson (Deborah Swanson) wrote:
> Rhodri James wrote, on January 05, 2017 3:53 AM
>>
>> On 05/01/17 04:52, Deborah Swanson wrote:
>>> My original question was in fact whether there was a way to make
>>> clickable hyperlinks in a console. I was persuaded after about 10
>>> replies that the answer was no,
>>
>> Then you were persuaded wrong; the actual answer was "this isn't a
>> meaningful question since it's based on incorrect assumptions."
>> Translating that to "No" is just as much a mistake as
>> translating it to
>> "Yes."
>
> Actually, your statement "this isn't a meaningful question since it's based on
> incorrect assumptions" is false. PyCharm outputs clickable links to the
> console, but they aren't web links, they simply link to lines of code.

Nope.  PyCharm outputs text to the console that the console chooses to 
interpret as a link and makes clickable.  As Stephen pointed out right 
back at the beginning of this thread, printing the textual string that 
is a URL could do exactly the same thing *if* the console you print to 
chooses to interpret it as such.  The choice is with the console, not 
your program; that there is the incorrect assumption.

-- 
Rhodri James *-* Kynesim Ltd


From rustompmody at gmail.com  Mon Jan  9 07:59:56 2017
From: rustompmody at gmail.com (Rustom Mody)
Date: Mon, 9 Jan 2017 04:59:56 -0800 (PST)
Subject: Temporary variables in list comprehensions
In-Reply-To: <mailman.376.1483964642.2395.python-list@python.org>
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
 <o4vpd4$nuu$1@blaine.gmane.org>
 <mailman.372.1483958517.2395.python-list@python.org>
 <871swc1pez.fsf@nightsong.com> <20170109061531.71e3c795@bigbox.christie.dr>
 <mailman.376.1483964642.2395.python-list@python.org>
Message-ID: <135a6b02-def4-4b59-b230-ee5a5a733bfd@googlegroups.com>

On Monday, January 9, 2017 at 5:54:15 PM UTC+5:30, Tim Chase wrote:
> On 2017-01-09 02:46, Paul Rubin wrote:
> > > gen = (expensive_calculation(x) for x in data)
> > > result = [(tmp, tmp + 1) for tmp in gen]  
> > 
> > result = [(tmp, tmp+1) for tmp in map(expensive_calculation, data)]
> 
> As charmingly expressive as map() is, the wildly different behavior in
> py3 (it's a generator that evaluates lazily) vs py2 (it consumes the
> entire iterable in one go) leads me to avoid it in general,
> especially when Python gives me list-comprehensions and generators
> that can do what I intend explicitly.  E.g., passing in
> itertools.count() as an iterable to map() will kill py2 but is
> perfectly fine in py3 (a horrible example):
> 
>   import itertools as i
>   for x in i.takewhile(
>       lambda n: n < 100, 
>       map(lambda g: g**2, i.count())
>       ):
>     print(x)
> 
> But yes, both ChrisA's pass-it-to-a-function and Serhiy's nested
> generate-the-tmp-values-then-operate-on-those are good solutions
> depending on how they feel in any particular context.  If I need to
> use an "if" clause in the outer generator that tests the resulting
> temp values, I use Serhiy's solution:
> 
>   [(tmp, tmp + 1)
>     for tmp in (
>       expensive_calculation(x)
>       for x in data
>       )
>     if tmp > 42
>     ]

What happens when the expensive is on an inner generator?
Something like:

[expensive?(y)  for x in data for y in foo(x)]

[The ? representing the 2 or more occurrences in Steven's eg]


From python at deborahswanson.net  Mon Jan  9 08:00:16 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 9 Jan 2017 05:00:16 -0800
Subject: Clickable hyperlinks
In-Reply-To: <6cafdb17-0a68-1000-abc0-fd8634fd473d@kynesim.co.uk>
Message-ID: <007401d26a78$530df890$27b23dae@sambora>

Rhodri James wrote, on January 09, 2017 4:28 AM
> 
> Nope.  PyCharm outputs text to the console that the console 
> chooses to 
> interpret as a link and makes clickable.  As Stephen pointed 
> out right 
> back at the beginning of this thread, printing the textual 
> string that 
> is a URL could do exactly the same thing *if* the console you 
> print to 
> chooses to interpret it as such.  The choice is with the console, not 
> your program; that there is the incorrect assumption.
> 
> -- 
> Rhodri James *-* Kynesim Ltd

Sorry, Rhodri. I don't agree with your logic. You can use tkinter (code
in a program) to make clickable links in the console, and the webbrowser
module to web-enable them so urls open in a browser when you click on
them.

I have no idea how this crowd got off on the mantra "The choice is with
the console".  Code does in fact have the power to control what happens
in the console. How do you think Linux does it on their terminals with
clickable links? Granted, the code may have to specify parameters for a
particular console, but I certainly wasn't asking for universal code
that would work with any console. That was something made up by the
responders on the thread, so they could revile me for such an
outrageously impossible demand. My original question was if Python had
anything equivalent to the hyperlink formula in Excel, which is a
program (code) feature. Nothing about doing it on any console in the
universe.

The developers who wrote PyCharm coded it for the console they were
using. The console is a dead thing, it has no mind or soul to choose
anything. Surely an educated person would know that.



From josemsuarezsierra at gmail.com  Mon Jan  9 08:08:51 2017
From: josemsuarezsierra at gmail.com (=?UTF-8?Q?Jos=C3=A9_Manuel_Su=C3=A1rez_Sierra?=)
Date: Mon, 9 Jan 2017 05:08:51 -0800 (PST)
Subject: Help with this code
Message-ID: <84a38553-c6bb-4c6d-9247-eb22a69fe897@googlegroups.com>

Hello, I am trying to make a code wich compares between 2 or several sequences (lists). It compares every element in a list with another list elements. For example, if we have a list_a=["a","b","c","d"] and list_b=["a","b"] I want to obtain a new list_c containing elements that match between these lists (a and b here), but, if for instance list_b were ["a","c"] the program must not store this data because they are not in same order.

Said this, I wrote this code but it doesnt work:

if __name__ == "__main__":


    def compare(a, b):

        i = 0
        j = 0
        c1 = []

        while a[i] == b[j]:
            c1.append(a[i])
                j = j+1
                i=i+1

        return c1




    cadena_1=raw_input("Introduce list 1 \n")
    cadena_2 = raw_input("Introduce list 2 \n")


    transf1=list(cad_1) 
    transf2 = list(cad_2)


    print compare(transf1,transf2)




Thank you


From antoon.pardon at rece.vub.ac.be  Mon Jan  9 08:12:24 2017
From: antoon.pardon at rece.vub.ac.be (Antoon Pardon)
Date: Mon, 9 Jan 2017 14:12:24 +0100
Subject: Temporary variables in list comprehensions
In-Reply-To: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <718d3926-e673-3d7b-e55c-8df5db719957@rece.vub.ac.be>

Op 09-01-17 om 04:53 schreef Steven D'Aprano:
> Suppose you have an expensive calculation that gets used two or more times in a 
> loop. The obvious way to avoid calculating it twice in an ordinary loop is with 
> a temporary variable:
>
> result = []
> for x in data:
>     tmp = expensive_calculation(x)
>     result.append((tmp, tmp+1))
>
>
> But what if you are using a list comprehension? Alas, list comps don't let you 
> have temporary variables, so you have to write this:
>
>
> [(expensive_calculation(x), expensive_calculation(x) + 1) for x in data]
>
>
> Or do you? ... no, you don't!
>
>
> [(tmp, tmp + 1) for x in data for tmp in [expensive_calculation(x)]]
>
>
> I can't decide whether that's an awesome trick or a horrible hack...

Maybe this in an occasion to use your recipe.

http://code.activestate.com/recipes/580625-collection-pipeline-in-python/

result = data | Map(expensive_calculation) | Map(lambda tmp: (tmp, tmp + 1)) | List

-- 
Antoon.



From python at deborahswanson.net  Mon Jan  9 08:39:33 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 9 Jan 2017 05:39:33 -0800
Subject: Help with this code
In-Reply-To: <84a38553-c6bb-4c6d-9247-eb22a69fe897@googlegroups.com>
Message-ID: <007a01d26a7d$d034e770$27b23dae@sambora>

Jos? Manuel Su?rez Sierra wrote, on January 09, 2017 5:09 AM
> 
> Hello, I am trying to make a code wich compares between 2 or 
> several sequences (lists). It compares every element in a 
> list with another list elements. For example, if we have a 
> list_a=["a","b","c","d"] and list_b=["a","b"] I want to 
> obtain a new list_c containing elements that match between 
> these lists (a and b here), but, if for instance list_b were 
> ["a","c"] the program must not store this data because they 
> are not in same order.
> 
> Said this, I wrote this code but it doesnt work:
> 
> if __name__ == "__main__":
> 
> 
>     def compare(a, b):
> 
>         i = 0
>         j = 0
>         c1 = []
> 
>         while a[i] == b[j]:
>             c1.append(a[i])
>                 j = j+1
>                 i=i+1
> 
>         return c1
> 
> 
> 
> 
>     cadena_1=raw_input("Introduce list 1 \n")
>     cadena_2 = raw_input("Introduce list 2 \n")
> 
> 
>     transf1=list(cad_1) 
>     transf2 = list(cad_2)
> 
> 
>     print compare(transf1,transf2)
> 
> 
> 
> 
> Thank you

I think your code assumes that a and b are the same length, and that all
the elements in the intersection (the ones in both lists) are in order
at the beginning of the list, like:

a = [1, 2, 5, 8, 22, 11, 14]
b = [1, 2, 5, 19, 12, 31, 42]

You only want to append the current list element if you test that it's
in both lists, and the answer is True. We do that with an 'if'
statement.

You need something like this, and a for loop would be the better choice
here.

cl = []
# look at every list element in 'a'
for c in a:
	# is this element in 'b'?
	if e in b:
		# if True, then append e to the result list, or continue
if False
		cl.append(e)
return cl

There's fancier ways to do it all in one line of code, but you need to
understand the fundamentals before you move on to tricks.

Deborah
		




From josemsuarezsierra at gmail.com  Mon Jan  9 08:46:44 2017
From: josemsuarezsierra at gmail.com (=?UTF-8?Q?Jos=C3=A9_Manuel_Su=C3=A1rez_Sierra?=)
Date: Mon, 9 Jan 2017 05:46:44 -0800 (PST)
Subject: Help with this code
In-Reply-To: <84a38553-c6bb-4c6d-9247-eb22a69fe897@googlegroups.com>
References: <84a38553-c6bb-4c6d-9247-eb22a69fe897@googlegroups.com>
Message-ID: <625c76bf-2548-4261-adc9-274cc77a5051@googlegroups.com>

El lunes, 9 de enero de 2017, 14:09:09 (UTC+1), Jos? Manuel Su?rez Sierra  escribi?:
> Hello, I am trying to make a code wich compares between 2 or several sequences (lists). It compares every element in a list with another list elements. For example, if we have a list_a=["a","b","c","d"] and list_b=["a","b"] I want to obtain a new list_c containing elements that match between these lists (a and b here), but, if for instance list_b were ["a","c"] the program must not store this data because they are not in same order.
> 
> Said this, I wrote this code but it doesnt work:
> 
> if __name__ == "__main__":
> 
> 
>     def compare(a, b):
> 
>         i = 0
>         j = 0
>         c1 = []
> 
>         while a[i] == b[j]:
>             c1.append(a[i])
>                 j = j+1
>                 i=i+1
> 
>         return c1
> 
> 
> 
> 
>     cadena_1=raw_input("Introduce list 1 \n")
>     cadena_2 = raw_input("Introduce list 2 \n")
> 
> 
>     transf1=list(cad_1) 
>     transf2 = list(cad_2)
> 
> 
>     print compare(transf1,transf2)
> 
> 
> 
> 
> Thank you

Thanks for your reply,
I wrote this code:
    def comparar(cad1, cad2):
        i = 0
        j = 0
        cad3 = []
        k = True

        for cad1[i] in cad1:
            k = True
            for cad2[j] in cad2:
                while cad1[i] == cad2[j] and i<= len(cad1) and j <= len(cad2):
                    cad3.append(cad1[i])
                    i = i + 1
                    j = j + 1

                    if cad1[i] != cad2[j]:
                        k = False
            i = i + 1
        return cad3

This is a function, another important thing is the order of elements, it must be ordered as it appears in one of the lists, in your example, my function must return a list with elements 1,2,5 in that order.

I cant find my mistake in these function I wrote you above.

Thank you very much


From __peter__ at web.de  Mon Jan  9 08:46:56 2017
From: __peter__ at web.de (Peter Otten)
Date: Mon, 09 Jan 2017 14:46:56 +0100
Subject: Help with this code
References: <84a38553-c6bb-4c6d-9247-eb22a69fe897@googlegroups.com>
Message-ID: <o5048c$bfq$1@blaine.gmane.org>

Jos? Manuel Su?rez Sierra wrote:

> Hello, 

Welcome!


> I am trying to make a code wich compares between 2 or several
> sequences (lists). It compares every element in a list with another list
> elements. For example, if we have a list_a=["a","b","c","d"] and
> list_b=["a","b"] I want to obtain a new list_c containing elements that
> match between these lists (a and b here), but, if for instance list_b were
> ["a","c"] the program must not store this data because they are not in
> same order.
> 
> Said this, I wrote this code but it doesnt work:

Get into the habit of describing what "doesn't work" as precisely as you 
can. That is the first and most important step to fixing a bug. Python often 
helps you with that task by producing a "traceback", in your case something 
like

$ python tmp3.py
  File "tmp3.py", line 12
    j = j+1
    ^
IndentationError: unexpected indent

probably with another filename and line number. This is the compiler trying 
to tell you that line 12 has more leading whitespace than the preceding one, 
something that should only occur e. g. for the body of a while-loop, not at 
random places like the

j = j+1

that follows the ordinary statement

c1.append(a[i])

Note that once you have fixed your code in this place you will run into 
another error. Read the traceback carefully and try to figure out what's 
going on. If you need help come back here or, better, ask on the tutor 
mailing list which is dedicated to newbies making their first steps with 
Python. Good luck!

> if __name__ == "__main__":
> 
> 
>     def compare(a, b):
> 
>         i = 0
>         j = 0
>         c1 = []
> 
>         while a[i] == b[j]:
>             c1.append(a[i])
>                 j = j+1
>                 i=i+1
> 
>         return c1
> 
> 
> 
> 
>     cadena_1=raw_input("Introduce list 1 \n")
>     cadena_2 = raw_input("Introduce list 2 \n")
> 
> 
>     transf1=list(cad_1)
>     transf2 = list(cad_2)
> 
> 
>     print compare(transf1,transf2)
> 
> 
> 
> 
> Thank you




From python.list at tim.thechases.com  Mon Jan  9 08:53:13 2017
From: python.list at tim.thechases.com (Tim Chase)
Date: Mon, 9 Jan 2017 07:53:13 -0600
Subject: Clickable hyperlinks
In-Reply-To: <007401d26a78$530df890$27b23dae@sambora>
References: <6cafdb17-0a68-1000-abc0-fd8634fd473d@kynesim.co.uk>
 <007401d26a78$530df890$27b23dae@sambora>
Message-ID: <20170109075313.583d49e2@bigbox.christie.dr>

On 2017-01-09 05:00, Deborah Swanson wrote:
> Code does in fact have the power to control what happens
> in the console. How do you think Linux does it on their terminals
> with clickable links? Granted, the code may have to specify
> parameters for a particular console, but I certainly wasn't asking
> for universal code that would work with any console.

Only to a degree.  Some consoles sniff the text sent to them for
particular URL-like patterns and linkify them for you.  All you have
to do is print a URL that its pattern-matching identifies:

  print("http://example.com")

However, as Rhodri details, *this is a feature of the terminal
emulator*. I've got a smattering of terminal emulators at my disposal
and many don't auto-linkify (xterm, rxvt, the base non-X terminal)
while others do (Gnome terminal).  And in the ones where it doesn't
work, it's because it's the *terminal* that doesn't support
linkifying, so no amount of work on the application's part will make
it linkify.

> The console is a dead thing, it has no mind or soul to choose
> anything. Surely an educated person would know that.

Pretty much every quality system administrator I know uses the
terminal.  Just about all of the best devs I know use the terminal.
Microsoft added Powershell because of demand. They added Ubuntu/bash
support because of demand.  It allows for powerful automation that
would otherwise require writing full-fledged scripts.  There is
nothing dead about it.

I'm not sure where you get your baseless claim that "an educated
person would know that", since someone who had taken the time to
study the state of terminal use would see that is far from dead.

-tkc





From python.list at tim.thechases.com  Mon Jan  9 09:21:43 2017
From: python.list at tim.thechases.com (Tim Chase)
Date: Mon, 9 Jan 2017 08:21:43 -0600
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <003301d26a45$cc04a5b0$27b23dae@sambora>
References: <o4tebf$al7$1@blaine.gmane.org>
 <003301d26a45$cc04a5b0$27b23dae@sambora>
Message-ID: <20170109082143.6b0a019f@bigbox.christie.dr>

On 2017-01-08 22:58, Deborah Swanson wrote:
> 1) I have a section that loops through the sorted data, compares two
> adjacent rows at a time, and marks one of them for deletion if the
> rows are identical.
> 
> I'm using 
> 
> for i in range(len(records)-1):
>     r1 = records[i]
>     r2 = records[i+1]
>     if r1.xx = r2.xx:
> 		.
> 		.
> and my question is whether there's a way to work with two adjacent
> rows without using subscripts?  

I usually wrap the iterable in something like

  def pairwise(it):
    prev = next(it)
    for thing in it:
      yield prev, thing
      prev = thing

  for prev, cur in pairwise(records):
    compare(prev, cur)

which I find makes it more readable.

-tkc




From josemsuarezsierra at gmail.com  Mon Jan  9 09:47:47 2017
From: josemsuarezsierra at gmail.com (=?UTF-8?Q?Jos=C3=A9_Manuel_Su=C3=A1rez_Sierra?=)
Date: Mon, 9 Jan 2017 06:47:47 -0800 (PST)
Subject: Help with this code
In-Reply-To: <84a38553-c6bb-4c6d-9247-eb22a69fe897@googlegroups.com>
References: <84a38553-c6bb-4c6d-9247-eb22a69fe897@googlegroups.com>
Message-ID: <36919c0e-ebc3-456f-889a-121081f28a37@googlegroups.com>

El lunes, 9 de enero de 2017, 14:09:09 (UTC+1), Jos? Manuel Su?rez Sierra  escribi?:
> Hello, I am trying to make a code wich compares between 2 or several sequences (lists). It compares every element in a list with another list elements. For example, if we have a list_a=["a","b","c","d"] and list_b=["a","b"] I want to obtain a new list_c containing elements that match between these lists (a and b here), but, if for instance list_b were ["a","c"] the program must not store this data because they are not in same order.
> 
> Said this, I wrote this code but it doesnt work:
> 
> if __name__ == "__main__":
> 
> 
>     def compare(a, b):
> 
>         i = 0
>         j = 0
>         c1 = []
> 
>         while a[i] == b[j]:
>             c1.append(a[i])
>                 j = j+1
>                 i=i+1
> 
>         return c1
> 
> 
> 
> 
>     cadena_1=raw_input("Introduce list 1 \n")
>     cadena_2 = raw_input("Introduce list 2 \n")
> 
> 
>     transf1=list(cad_1) 
>     transf2 = list(cad_2)
> 
> 
>     print compare(transf1,transf2)
> 
> 
> 
> 
> Thank you

Thank you!

Here is my code, I dont understand why it doesnt work very well:
if __name__ == "__main__":


    cadena_1 = raw_input("Introduce la cadena 1 \n")
    cadena_2 = raw_input("Introduce la cadena 2 \n")
    # n=input("De cuantas letras quieres hacer la comparacion?\n")

    transf1 = list(cadena_1)  
    transf2 = list(cadena_2)
    l1=len(transf1)
    l2=len(transf2)
    c3=[]
    i=0
    j=0


    for transf1[i] in transf1:          
        for transf2[j] in transf2:   
            if transf1[i]==transf2[j]: 
                c3.append(transf1[i])   
                i=i+1                   
                j=j+1                   
            else:                      
                j=j+1                   

    print c3

This is the traceback:
line 18, in <module>
   for transf2[j] in transf2:
IndexError: list assignment index out of range

If I have initialized j=0 (such as i) why does it not work?
I want the script to read sequence 1 and compares every element inside it with elements in sequence 2 no mattering where it matches.

Thank you!


From __peter__ at web.de  Mon Jan  9 09:51:14 2017
From: __peter__ at web.de (Peter Otten)
Date: Mon, 09 Jan 2017 15:51:14 +0100
Subject: Using namedtuples field names for column indices in a list of
 lists
References: <o4tebf$al7$1@blaine.gmane.org>
 <003301d26a45$cc04a5b0$27b23dae@sambora>
Message-ID: <o50811$cnn$1@blaine.gmane.org>

Deborah Swanson wrote:

> Even better, to get hold of all the records with the same Description as
> the current row, compare them all, mark all but the different ones for
> deletion, and then resume processing the records after the last one?

When you look at all fields for deduplication anyway there's no need to 
treat one field (Description) specially. Just

records = set(records)

should be fine. As the initial order is lost* you probably want to sort 
afterwards. The code then becomes

records = sorted(
    set(records), 
    key=operator.attrgetter("Description")
)

Now if you want to fill in missing values, you should probably do this 
before deduplication -- and the complete() function introduced in

https://mail.python.org/pipermail/python-list/2016-December/717847.html

can be adapted to work with namedtuples instead of dicts.

(*) If you want to preserve the initial order you can use a 
collections.OrderedDict instead of the set.




From rhodri at kynesim.co.uk  Mon Jan  9 10:15:04 2017
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Mon, 9 Jan 2017 15:15:04 +0000
Subject: Clickable hyperlinks
In-Reply-To: <20170109075313.583d49e2@bigbox.christie.dr>
References: <6cafdb17-0a68-1000-abc0-fd8634fd473d@kynesim.co.uk>
 <007401d26a78$530df890$27b23dae@sambora>
 <20170109075313.583d49e2@bigbox.christie.dr>
Message-ID: <e127b661-5df1-74bb-202a-5fb0ec46b8ee@kynesim.co.uk>

On 09/01/17 13:53, Tim Chase wrote:
> On 2017-01-09 05:00, Deborah Swanson wrote:
>> The console is a dead thing, it has no mind or soul to choose
>> anything. Surely an educated person would know that.
>
> Pretty much every quality system administrator I know uses the
> terminal.  Just about all of the best devs I know use the terminal.
> Microsoft added Powershell because of demand. They added Ubuntu/bash
> support because of demand.  It allows for powerful automation that
> would otherwise require writing full-fledged scripts.  There is
> nothing dead about it.

I think you're falling foul of Deborah's inability to communicate again. 
  I think she meant to say that the console is dumb, not dead.  In a 
very strict sense that's almost true, but since we've been using 
"console" interchangeably with "terminal emulator" throughout this 
discussion, it's hilariously wrong.

-- 
Rhodri James *-* Kynesim Ltd


From ghasselbring at hotmail.com  Mon Jan  9 10:54:15 2017
From: ghasselbring at hotmail.com (Gretchen Hasselbring)
Date: Mon, 9 Jan 2017 15:54:15 +0000
Subject: Error message IDLE
In-Reply-To: <HE1PR0602MB28116020D7BA058EAA5B39EAD8640@HE1PR0602MB2811.eurprd06.prod.outlook.com>
References: <HE1PR0602MB28116020D7BA058EAA5B39EAD8640@HE1PR0602MB2811.eurprd06.prod.outlook.com>
Message-ID: <HE1PR0602MB2811F85C03FE9F9652CD8FA9D8640@HE1PR0602MB2811.eurprd06.prod.outlook.com>

FYI

Turns out I was saving my practice exercises as files (.py) under the python directory which conflicted with the running of Idle.  All cleared up now.

Sent from my iPad

> On 9 Jan 2017, at 12:16, Gretchen Hasselbring <ghasselbring at hotmail.com> wrote:
> 
> Hello
> 
> Trying to learn python on a laptop.  Was successful for awhile then...
> 
> Had a 'subprocess startup error'
> 
> 'IDLE's subprocess didn't make connection.  Either IDLE can't start subprocess or personal firewall software is blocking the connection '
> 
> 
> Doesn't appear to be firewall and I uninstalled and reinstalled python 3.6.032 bit???
> 
> Any advice?
> Thanks
> 
> 
> Sent from my iPad
> -- 
> https://mail.python.org/mailman/listinfo/python-list


From tjreedy at udel.edu  Mon Jan  9 10:58:52 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Mon, 9 Jan 2017 10:58:52 -0500
Subject: Error message IDLE
In-Reply-To: <HE1PR0602MB28116020D7BA058EAA5B39EAD8640@HE1PR0602MB2811.eurprd06.prod.outlook.com>
References: <HE1PR0602MB28116020D7BA058EAA5B39EAD8640@HE1PR0602MB2811.eurprd06.prod.outlook.com>
Message-ID: <o50bvp$1pb$1@blaine.gmane.org>

On 1/9/2017 6:48 AM, Gretchen Hasselbring wrote:
> Hello
>
> Trying to learn python on a laptop.  Was successful for awhile then...
>
> Had a 'subprocess startup error'
>
> 'IDLE's subprocess didn't make connection.  Either IDLE can't start subprocess or personal firewall software is blocking the connection '
>
>
> Doesn't appear to be firewall and I uninstalled and reinstalled python 3.6.032 bit???
>
> Any advice?

When IDLE works consistently and then consistently does not work, 
something changed on your system.  Since reinstalling did not fix the 
issue, the change was not in Python and IDLE.  The first thing to do is 
to run IDLE from your system's console with '<path to>/python -m 
idlelib' and see if an error message appears.

There are at least 5 other possible causes, including

1. You created a file with the same name as a stdlib mdoule. (Rename it.)
2. There is a problem with a config file in $HOME/.idlerc/.  (Easier is 
to delete.)
3. Some network setting change cause socket connection to fail.

-- 
Terry Jan Reedy



From __peter__ at web.de  Mon Jan  9 10:59:17 2017
From: __peter__ at web.de (Peter Otten)
Date: Mon, 09 Jan 2017 16:59:17 +0100
Subject: Help with this code
References: <84a38553-c6bb-4c6d-9247-eb22a69fe897@googlegroups.com>
 <36919c0e-ebc3-456f-889a-121081f28a37@googlegroups.com>
Message-ID: <o50c0j$cj6$1@blaine.gmane.org>

Jos? Manuel Su?rez Sierra wrote:

> This is the traceback:
> line 18, in <module>
> for transf2[j] in transf2:
> IndexError: list assignment index out of range
> 
> If I have initialized j=0 (such as i) why does it not work?

A for loop

for x in y:
   ...

sequentually assigns every value in y to x. So with y = "ab" it executes

x = "a"
...
x = "b"
...

This is the case even when there is something more complex like transf2[j]:

for transf2[j] in y:
    ...

translates to

transf2[j] = "a"
...  # both transf2 and j may be rebound here and thus affect
transf2[j] = "b" # what this actually does
...

and thus can fail with an IndexError when j is bound to a value greater than 
the length of the transf2 list. 

But most likely you want to avoid this feature of Python -- even the experts 
never use it.

> I want the script to read sequence 1 and compares every element inside it
> with elements in sequence 2 no mattering where it matches.

That may be sufficient to explain the objective to a human who already has a 
rough idea of your goal, but to come up with an actual algorithm you need to 
think about -- and communicate -- a lot more detail.

There is a third party module that operates on strings, not lists which 
finds the edit operations

>>> Levenshtein.editops("abcdefgj", "axcdyezfg")
[('replace', 1, 1), ('insert', 4, 4), ('insert', 5, 6), ('delete', 7, 9)]

What should your function return given the equivalent lists

['a', 'b', 'c', 'd', 'e', 'f', 'g', 'j']
['a', 'x', 'c', 'd', 'y', 'e', 'z', 'f', 'g']

? Try to make your plain-english description as precise as possible before 
you start coding.




From __peter__ at web.de  Mon Jan  9 11:05:01 2017
From: __peter__ at web.de (Peter Otten)
Date: Mon, 09 Jan 2017 17:05:01 +0100
Subject: Error message IDLE
References: <HE1PR0602MB28116020D7BA058EAA5B39EAD8640@HE1PR0602MB2811.eurprd06.prod.outlook.com>
 <HE1PR0602MB2811F85C03FE9F9652CD8FA9D8640@HE1PR0602MB2811.eurprd06.prod.outlook.com>
Message-ID: <o50cb9$803$1@blaine.gmane.org>

Gretchen Hasselbring wrote:

> FYI
> 
> Turns out I was saving my practice exercises as files (.py) under the
> python directory which conflicted with the running of Idle.  All cleared
> up now.

Thanks for the update. Can you tell which file you shadowed to cause the 
error? Perhaps even if the underlying problem turns out to be hard to fix at 
least the error message could be improved.




From alemos at plux.info  Mon Jan  9 11:17:41 2017
From: alemos at plux.info (=?UTF-8?B?QW5kcsOpIExlbW9z?=)
Date: Mon, 9 Jan 2017 16:17:41 +0000
Subject: enable-framework Vs. Naught
Message-ID: <CAJ4-95X7TyqAzauwZrkrJ70fOw_1sCQgmy7j4vJKiFZAdJizpA@mail.gmail.com>

Hi,


I have a C++ module that I am compiling to use inside of my Python
installation under Mac OS.

If I compile & link it against a Framework enabled Python installation, it
works fine, but if I compile & link it against a *non* enabled Framework
installation that we use for distribution, I simply get a non inspiring:

Fatal Python error: PyThreadState_Get: no current thread


I am using python-config to get my flags on both the examples, but I simply
cannot get it to run (although it compiles fine) on a *non* enabled
Framework installation.


Thoughts/Help?



--
Andr? Lemos


From breamoreboy at gmail.com  Mon Jan  9 11:31:55 2017
From: breamoreboy at gmail.com (breamoreboy at gmail.com)
Date: Mon, 9 Jan 2017 08:31:55 -0800 (PST)
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <mailman.386.1483971726.2395.python-list@python.org>
References: <o4tebf$al7$1@blaine.gmane.org>
 <003301d26a45$cc04a5b0$27b23dae@sambora>
 <20170109082143.6b0a019f@bigbox.christie.dr>
 <mailman.386.1483971726.2395.python-list@python.org>
Message-ID: <51c2cf13-b516-4ebf-8ca9-a915520adcab@googlegroups.com>

On Monday, January 9, 2017 at 2:22:19 PM UTC, Tim Chase wrote:
> On 2017-01-08 22:58, Deborah Swanson wrote:
> > 1) I have a section that loops through the sorted data, compares two
> > adjacent rows at a time, and marks one of them for deletion if the
> > rows are identical.
> > 
> > I'm using 
> > 
> > for i in range(len(records)-1):
> >     r1 = records[i]
> >     r2 = records[i+1]
> >     if r1.xx = r2.xx:
> > 		.
> > 		.
> > and my question is whether there's a way to work with two adjacent
> > rows without using subscripts?  
> 
> I usually wrap the iterable in something like
> 
>   def pairwise(it):
>     prev = next(it)
>     for thing in it:
>       yield prev, thing
>       prev = thing
> 
>   for prev, cur in pairwise(records):
>     compare(prev, cur)
> 
> which I find makes it more readable.
> 
> -tkc

Or from https://docs.python.org/3/library/itertools.html#itertools-recipes:-

def pairwise(iterable):
    "s -> (s0,s1), (s1,s2), (s2, s3), ..."
    a, b = tee(iterable)
    next(b, None)
    return zip(a, b)

This and many other recipes are available in the more-itertools module which is on pypi.


From ghasselbring at hotmail.com  Mon Jan  9 12:02:02 2017
From: ghasselbring at hotmail.com (Gretchen Hasselbring)
Date: Mon, 9 Jan 2017 17:02:02 +0000
Subject: Error message IDLE
In-Reply-To: <o50cb9$803$1@blaine.gmane.org>
References: <HE1PR0602MB28116020D7BA058EAA5B39EAD8640@HE1PR0602MB2811.eurprd06.prod.outlook.com>
 <HE1PR0602MB2811F85C03FE9F9652CD8FA9D8640@HE1PR0602MB2811.eurprd06.prod.outlook.com>,
 <o50cb9$803$1@blaine.gmane.org>
Message-ID: <HE1PR0602MB2811010E2A2677A501DDB32CD8640@HE1PR0602MB2811.eurprd06.prod.outlook.com>

Thank you for your responses.  The file I think is responsible was called types.py





Sent from my iPad

> On 9 Jan 2017, at 16:11, Peter Otten <__peter__ at web.de> wrote:
> 
> Gretchen Hasselbring wrote:
> 
>> FYI
>> 
>> Turns out I was saving my practice exercises as files (.py) under the
>> python directory which conflicted with the running of Idle.  All cleared
>> up now.
> 
> Thanks for the update. Can you tell which file you shadowed to cause the 
> error? Perhaps even if the underlying problem turns out to be hard to fix at 
> least the error message could be improved.
> 
> 
> -- 
> https://mail.python.org/mailman/listinfo/python-list


From python.list at tim.thechases.com  Mon Jan  9 12:08:30 2017
From: python.list at tim.thechases.com (Tim Chase)
Date: Mon, 9 Jan 2017 11:08:30 -0600
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <51c2cf13-b516-4ebf-8ca9-a915520adcab@googlegroups.com>
References: <o4tebf$al7$1@blaine.gmane.org>
 <003301d26a45$cc04a5b0$27b23dae@sambora>
 <20170109082143.6b0a019f@bigbox.christie.dr>
 <mailman.386.1483971726.2395.python-list@python.org>
 <51c2cf13-b516-4ebf-8ca9-a915520adcab@googlegroups.com>
Message-ID: <20170109110830.42cb734e@bigbox.christie.dr>

On 2017-01-09 08:31, breamoreboy at gmail.com wrote:
> On Monday, January 9, 2017 at 2:22:19 PM UTC, Tim Chase wrote:
> > I usually wrap the iterable in something like
> > 
> >   def pairwise(it):
> >     prev = next(it)
> >     for thing in it:
> >       yield prev, thing
> >       prev = thing
> 
> Or from
> https://docs.python.org/3/library/itertools.html#itertools-recipes:-
> 
> def pairwise(iterable):
>     "s -> (s0,s1), (s1,s2), (s2, s3), ..."
>     a, b = tee(iterable)
>     next(b, None)
>     return zip(a, b)
> 
> This and many other recipes are available in the more-itertools
> module which is on pypi. 

Ah, helpful to not have to do it from scratch each time.  Also, I see
several others that I've coded up from scratch (particularly the
partition() and first_true() functions).

I usually want to make sure it's tailored for my use cases. The above
pairwise() is my most common use case, but I occasionally want N-wise
pairing

  s -> (s0,s1,?sN), (s1,s2,?S{N+1}), (s2,s3,?s{N+2}), ?

or to pad them out so either the leader/follower gets *all* of the
values, with subsequent values being a padding value:

  # lst = [s0, s1, s2]
  (s0,s1), (s1, s2), (s2, PADDING)
  # or
  (PADDING, s0), (s0, s1), (s1, s2)

but it's good to have my common cases already coded & tested.

-tkc




From python.list at tim.thechases.com  Mon Jan  9 12:11:29 2017
From: python.list at tim.thechases.com (Tim Chase)
Date: Mon, 9 Jan 2017 11:11:29 -0600
Subject: Temporary variables in list comprehensions
In-Reply-To: <135a6b02-def4-4b59-b230-ee5a5a733bfd@googlegroups.com>
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
 <o4vpd4$nuu$1@blaine.gmane.org>
 <mailman.372.1483958517.2395.python-list@python.org>
 <871swc1pez.fsf@nightsong.com>
 <20170109061531.71e3c795@bigbox.christie.dr>
 <mailman.376.1483964642.2395.python-list@python.org>
 <135a6b02-def4-4b59-b230-ee5a5a733bfd@googlegroups.com>
Message-ID: <20170109111129.0170a709@bigbox.christie.dr>

On 2017-01-09 04:59, Rustom Mody wrote:
> What happens when the expensive is on an inner generator?
> Something like:
> 
> [expensive?(y)  for x in data for y in foo(x)]
> 
> [The ? representing the 2 or more occurrences in Steven's eg]

Well, if I understand your question correctly, the goal would be to
execute each expensive operation only once, regardless of how many
expensive functions you execute:

  [(x, a, b, x+1, a+1, b+1)
   for x, a, b
   in (
     x,
     expensive_a(x),
     expensive_b(x),
     for x
     in data
     )
   # if x > 42 # optionally test against values
   ]

-tkc





From torriem at gmail.com  Mon Jan  9 12:27:41 2017
From: torriem at gmail.com (Michael Torrie)
Date: Mon, 9 Jan 2017 10:27:41 -0700
Subject: Clickable hyperlinks
In-Reply-To: <007401d26a78$530df890$27b23dae@sambora>
References: <007401d26a78$530df890$27b23dae@sambora>
Message-ID: <a6503766-f23f-6e2e-1e4d-be1105efbbd9@gmail.com>

On 01/09/2017 06:00 AM, Deborah Swanson wrote:
> Rhodri James wrote, on January 09, 2017 4:28 AM
>>
>> Nope.  PyCharm outputs text to the console that the console 
>> chooses to 
>> interpret as a link and makes clickable.  As Stephen pointed 
>> out right 
>> back at the beginning of this thread, printing the textual 
>> string that 
>> is a URL could do exactly the same thing *if* the console you 
>> print to 
>> chooses to interpret it as such.  The choice is with the console, not 
>> your program; that there is the incorrect assumption.
> Sorry, Rhodri. I don't agree with your logic. 

You may, but that doesn't change the fact that Rhodri's post is 100%
accurate.

> You can use tkinter (code
> in a program) to make clickable links in the console, 

Unless you're talking about an implementation of a console or terminal
emulator in tkinter, this is incorrect.  Tkinter does not do anything
with standard out.

> and the webbrowser
> module to web-enable them so urls open in a browser when you click on
> them.
> 
> I have no idea how this crowd got off on the mantra "The choice is with
> the console".  

I guess things keep going in circles because people are just trying to
help you understand what these various parts of the system are and how
they fit together, particularly with regards to so-called "console
applications."  (Text-mode, terminal-based, etc.)

> Code does in fact have the power to control what happens
> in the console.

Other than a pre-arranged protocol (win32 console api, ANSI, VT100, or
similar) between the displayer of the bytes and the python program, code
does not in fact have power to control what happens in the "console."

> How do you think Linux does it on their terminals with
> clickable links? 

This is just the terminal emulator trying to be smart and assuming
meaning in the bytes given to it, which may be a valid assumption on its
part, or may  not.  This is no way implies that all terminal emulators
should do this, nor do most terminal emulators.

> Granted, the code may have to specify parameters for a
> particular console, but I certainly wasn't asking for universal code
> that would work with any console. 

Your initial query back in the beginning did not state this.  Indeed you
never stated which console you wanted to work with. We addressed several
common ones including the Win32 console window (which cmd.exe runs in)
and various terminal emulators.

> That was something made up by the
> responders on the thread, so they could revile me for such an
> outrageously impossible demand. My original question was if Python had
> anything equivalent to the hyperlink formula in Excel, which is a
> program (code) feature. Nothing about doing it on any console in the
> universe.

I read frustration in several posts, but never reviling!

> The developers who wrote PyCharm coded it for the console they were
> using. 

The PyCharm developers built their own window to display "console"
output (standard-out bytes) from the app, and they could have their own
window interpret bytes and messages however they wanted to, and added
their own PyCharm-specific feature including hot links to error
locations (I think that comes from standard-err, though, not
standard-out). So if you want the PyCharm output window to create a
clickable hot-link for you you have to modify the PyCharm code to do that.

> The console is a dead thing, it has no mind or soul to choose
> anything. Surely an educated person would know that.

Not sure what you mean by that?


From __peter__ at web.de  Mon Jan  9 12:30:30 2017
From: __peter__ at web.de (Peter Otten)
Date: Mon, 09 Jan 2017 18:30:30 +0100
Subject: Search a sequence for its minimum and stop as soon as the lowest
 possible value is found
References: <o4o84h$klm$1@blaine.gmane.org>
 <mailman.285.1483711463.2395.python-list@python.org>
 <725de1f8-42f4-4cef-9ca3-58a2c7477576@googlegroups.com>
Message-ID: <o50hbi$jna$1@blaine.gmane.org>

Antonio Caminero Garcia wrote:

> On Friday, January 6, 2017 at 6:04:33 AM UTC-8, Peter Otten wrote:
>> Example: you are looking for the minimum absolute value in a series of
>> integers. As soon as you encounter the first 0 it's unnecessary extra
>> work to check the remaining values, but the builtin min() will continue.
>> 
>> The solution is a minimum function that allows the user to specify a stop
>> value:
>> 
>> >>> from itertools import count, chain
>> >>> stopmin(chain(reversed(range(10)), count()), key=abs, stop=0)
>> 0
>> 
>> How would you implement stopmin()?
>> 
>> Currently I raise an exception in the key function:
>> 
>> class Stop(Exception):
>>     pass
>> 
>> def stopmin(items, key, stop):
>>     """
>>     >>> def g():
>>     ...     for i in reversed(range(10)):
>>     ...         print(10*i)
>>     ...         yield str(i)
>>     >>> stopmin(g(), key=int, stop=5)
>>     90
>>     80
>>     70
>>     60
>>     50
>>     '5'
>>     """
>>     def key2(value):
>>         result = key(value)
>>         if result <= stop:
>>             raise Stop(value)
>>         return result
>>     try:
>>         return min(items, key=key2)
>>     except Stop as stop:
>>         return stop.args[0]
> 
> This is the simplest version I could come up with. I also like the classic
> 100% imperative, but it seems that is not trendy between the solutions
> given :D.
> 
> you can test it here https://repl.it/FD5A/0
> source code:
> 
> from itertools import accumulate
> 
> # stopmin calculates the greatest lower bound (infimum).
> # 
https://upload.wikimedia.org/wikipedia/commons/0/0a/Infimum_illustration.svg
> 
> def takeuntil(pred, seq):
>   for item in seq:
>     yield item
>     if not pred(item):

The "not": one of those decisions that can drive programmers into madness ;)

>       break
> 
> def stopmin(seq, stop=0):
>   drop_ltstop = (item for item in seq if item >= stop)
>   min_gen = (min_ for min_ in accumulate(drop_ltstop, func=min))

    You don't need the genexp here; just accumulate() will do.
    Using accumulate() is a nice suggestion, by the way.

>   return list(takeuntil(lambda x: x!= stop, min_gen))[-1]

 
> seq = [1, 4, 7, -8, 0, 7, -8, 9] # 0 just until zero is generated
> seq = [1, 4, 7, -8, 7, -8, 9] # 1 the entire sequence is generated
> 
> print(stopmin(seq, stop=0))

Once it passes my doctests your code isn't quite as simple, but still 
readable:

from itertools import accumulate
from operator import itemgetter
from collections import deque

firstitem = itemgetter(0)


def takeuntil(pred, items):
    for item in items:
        yield item
        if pred(item):
            break


def last(items):
    tail = deque(items, maxlen=1)
    if tail:
        return tail.pop()
    else:
        raise ValueError


def minkey(a, b):
    return min(a, b, key=firstitem)


def stopmin(items, *, key, stop):
    """
    >>> def g():
    ...     for i in reversed(range(10)):
    ...         print(10*i)
    ...         yield str(i)
    >>> stopmin(g(), key=int, stop=5)
    90
    80
    70
    60
    50
    '5'
    >>> stopmin(g(), key=int, stop=8.5)
    90
    80
    '8'
    >>> stopmin(g(), key=int, stop=9)
    90
    '9'
    >>> stopmin([10, 9, -11, 7, -12], key=abs, stop=0)
    7
    >>> try: stopmin([], key=abs, stop=0)
    ... except ValueError: print('OK')
    OK
    >>> stopmin("a", key=lambda x: print(x) or "c", stop="b")
    a
    'a'
    >>> class A:
    ...    def __init__(self, key):
    ...        self.key = key
    >>> stopmin([A(2), A(2), A(1), A(0)], key=lambda a: a.key, stop=1.1).key
    1
    """
    pairs = ((key(item), item) for item in items)
    descending_pairs = accumulate(pairs, func=minkey)
    return last(takeuntil(lambda p: p[0] <= stop, descending_pairs))[1]




From exarkun at twistedmatrix.com  Mon Jan  9 12:58:24 2017
From: exarkun at twistedmatrix.com (Jean-Paul Calderone)
Date: Mon, 9 Jan 2017 12:58:24 -0500
Subject: Announcing txAWS 0.2.3.1
Message-ID: <CAEeXt4PSgAGjFbj50=mUytatk5=0tu_UzhV6au+gvqCfWP_a7Q@mail.gmail.com>

I've just release txAWS 0.2.3.1.  txAWS is a library for interacting with
Amazon Web Services (AWS) using Twisted.

AWSServiceEndpoint's ssl_hostname_verification's parameter now defaults to
True instead of False.  This affects all txAWS APIs which issue requests to
AWS endpoints.  For any application which uses the default
AWSServiceEndpoints, the server's TLS certificate will now be verified.

This resolves a security issue in which txAWS applications were vulnerable
to man-in-the-middle attacks which could either steal sensitive information
or, possibly, alter the AWS operation requested.

The new release is available on PyPI in source and wheel forms.  You can
also find txAWS at its new home on github, <https://github.com/twisted/txaws
>.

Special thanks to Least Authority Enterprises
(<https://leastauthority.com/>) for
sponsoring the work to find and fix this issue and to publish this new
release.

Jean-Paul


From Joaquin.Alzola at lebara.com  Mon Jan  9 13:14:45 2017
From: Joaquin.Alzola at lebara.com (Joaquin Alzola)
Date: Mon, 9 Jan 2017 18:14:45 +0000
Subject: Help with this code
In-Reply-To: <PeQcA.459692$Yj7.154339@fx15.am4>
References: <84a38553-c6bb-4c6d-9247-eb22a69fe897@googlegroups.com>
 <PeQcA.459692$Yj7.154339@fx15.am4>
Message-ID: <DB5PR07MB0806C2B0B456515C91BD31DAF0640@DB5PR07MB0806.eurprd07.prod.outlook.com>

>> elements. For example, if we have a list_a=["a","b","c","d"] and
>> list_b=["a","b"] I want to obtain a new list_c containing elements that
>> match between these lists (a and b here),

>Perhaps this might work:

>>>> list(set(list_a).intersection(set(list_b)))
>['a', 'b']

>>> list_a={"a","b","c","d"}
>>> list_b={"a","b"}
> sorted(list_a & list_b)
['a', 'b']

------

This email is confidential and may be subject to privilege. If you are not the intended recipient, please do not copy or disclose its content but contact the sender immediately upon receipt.

From joel.goldstick at gmail.com  Mon Jan  9 13:43:35 2017
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Mon, 9 Jan 2017 13:43:35 -0500
Subject: Help with this code
In-Reply-To: <PeQcA.459692$Yj7.154339@fx15.am4>
References: <84a38553-c6bb-4c6d-9247-eb22a69fe897@googlegroups.com>
 <PeQcA.459692$Yj7.154339@fx15.am4>
Message-ID: <CAPM-O+ys-mvC38qSTFDJL6Ky8xNeLNdo-s1veFWHG1TggaarTQ@mail.gmail.com>

On Mon, Jan 9, 2017 at 1:02 PM, Gilmeh Serda
<gilmeh.serdah at nothing.here.invalid> wrote:
> On Mon, 09 Jan 2017 05:08:51 -0800, Jos? Manuel Su?rez Sierra wrote:
>
>> elements. For example, if we have a list_a=["a","b","c","d"] and
>> list_b=["a","b"] I want to obtain a new list_c containing elements that
>> match between these lists (a and b here),
>
> Perhaps this might work:
>
>>>> list(set(list_a).intersection(set(list_b)))
> ['a', 'b']
>
> HTH
> --
> Gilmeh
> --
> https://mail.python.org/mailman/listinfo/python-list

I was confused whether the OP wanted to retain the list order.  The
spec seemed unclear. If not, this is a nice approach.  Of course this
also removes duplicate values.

-- 
Joel Goldstick
http://joelgoldstick.com/blog
http://cc-baseballstats.info/stats/birthdays


From torriem at gmail.com  Mon Jan  9 14:00:13 2017
From: torriem at gmail.com (Michael Torrie)
Date: Mon, 9 Jan 2017 12:00:13 -0700
Subject: Clickable hyperlinks
In-Reply-To: <a6503766-f23f-6e2e-1e4d-be1105efbbd9@gmail.com>
References: <007401d26a78$530df890$27b23dae@sambora>
 <a6503766-f23f-6e2e-1e4d-be1105efbbd9@gmail.com>
Message-ID: <968c2174-f32d-d225-9b81-549c3c998c67@gmail.com>

On 01/09/2017 10:27 AM, Michael Torrie wrote:
>> You can use tkinter (code
>> in a program) to make clickable links in the console, 
> 
> Unless you're talking about an implementation of a console or terminal
> emulator in tkinter, this is incorrect.  Tkinter does not do anything
> with standard out.

To be clearer, what I mean is that using Tkinter or some other toolkit
you can indeed place links on a GUI form or window.  But this has
nothing to do with a terminal emulator or console (meaning the display
of standard-out bytes).

Using your understanding of the word, console, Tkinter could be used to
create a console of your own that displays the output from other
processes and implements clickable hyperlinks, but Tkinter itself does
not display using standard out, and thus cannot cause a terminal
emulator or Windows console to display hyperlinks in a clickable fashion.



From tonycamgar at gmail.com  Mon Jan  9 14:15:59 2017
From: tonycamgar at gmail.com (Antonio Caminero Garcia)
Date: Mon, 9 Jan 2017 11:15:59 -0800 (PST)
Subject: Temporary variables in list comprehensions
In-Reply-To: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <11bfb5cd-c8c3-408a-bedb-ca9eafb78460@googlegroups.com>

On Sunday, January 8, 2017 at 7:53:37 PM UTC-8, Steven D'Aprano wrote:
> Suppose you have an expensive calculation that gets used two or more times in a 
> loop. The obvious way to avoid calculating it twice in an ordinary loop is with 
> a temporary variable:
> 
> result = []
> for x in data:
>     tmp = expensive_calculation(x)
>     result.append((tmp, tmp+1))
> 
> 
> But what if you are using a list comprehension? Alas, list comps don't let you 
> have temporary variables, so you have to write this:
> 
> 
> [(expensive_calculation(x), expensive_calculation(x) + 1) for x in data]
> 
> 
> Or do you? ... no, you don't!
> 
> 
> [(tmp, tmp + 1) for x in data for tmp in [expensive_calculation(x)]]
> 
> 
> I can't decide whether that's an awesome trick or a horrible hack...
> 
> 
> -- 
> Steven
> "Ever since I learned about confirmation bias, I've been seeing 
> it everywhere." - Jon Ronson

Hello I saw some memoizing functions, in that sense you can use the functools.lru_cache decorator, that is even better if you have repeated elements in data.

@functools.lru_cache
def expensive_calculation(x):
    # very NP-hard calculation
    pass


Hope that helps :)


From auriocus at gmx.de  Mon Jan  9 14:43:01 2017
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Mon, 9 Jan 2017 20:43:01 +0100
Subject: Temporary variables in list comprehensions
In-Reply-To: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <o50p18$3q6$1@dont-email.me>

Am 09.01.17 um 04:53 schrieb Steven D'Aprano:
> Or do you? ... no, you don't!
>
> [(tmp, tmp + 1) for x in data for tmp in [expensive_calculation(x)]]
>
> I can't decide whether that's an awesome trick or a horrible hack...

I think this is quite clear, and a useful feature, only that Python 
makes it unnecessarily hard. In Haskell, there is a "let" clause, which 
would allow to write it as:

	[let tmp = expensive_calc(x), (tmp, tmp+1)  for x in data]

or better readable using "with" or "where" as in

	[(tmp, tmp + 1) with tmp = expensive_calc(x) for x in data]
	
or similar. So maybe that's a PEP to extend the list comprehension syntax?

	Christian


From danny.adair at unfold.co.nz  Mon Jan  9 16:01:05 2017
From: danny.adair at unfold.co.nz (Danny Adair)
Date: Tue, 10 Jan 2017 10:01:05 +1300
Subject: [PSF-Community] Python Events in 2017, Need your help.
In-Reply-To: <20170109095449.v4ual5czl5mc7xxs@sg1>
References: <20170109095449.v4ual5czl5mc7xxs@sg1>
Message-ID: <CAM7XvD0dGbw3LqafSer9Z+YL32FEfHYj3v=jDvz=o0E5iiaKMQ@mail.gmail.com>

Thanks Stephane,

Kiwi PyCon 2017 will be in Auckland, New Zealand in September - exact
dates and location not yet determined. I'll submit it when they are.

Cheers,
Danny


On Mon, Jan 9, 2017 at 10:54 PM, Stephane Wirtel via PSF-Community
<psf-community at python.org> wrote:
> Dear Community,
>
> For the PythonFOSDEM [1] on 4th and 5th February in Belgium, I would like to
> present some slides with the Python events around the World.  Based on
> https://python.org/events, I have noted that there are missing events, for
> example:
>
> * PyCon Otto: Italy
> * PyCon UK: United Kingdom
> * PyCon CA: Canada
> * PyCon Ireland: Ireland
> * PyCon France: France
>
> Some of these events are not yet announced and I understand they are in the
> second semester, and thus, they don't know the location and the dates,
> excepted for PyCon Otto (April).
>
> In fact, I have noted that we know some big events in the Python community
> (for example: PyCon US and EuroPython) but do you know the others events,
> maybe the local event, PyCon IE, PyCon UK or PyCon IT.
>
> I like to know where there is a PyCon or a Django Conf or a PyData Event.
>
> In fact, I think we can help the Python Community if we submit all the
> events in https://python.org/events.
>
> This page has been created by the PSF and is maintained by some volunteers.
>
> I know this list of events:
> * PyCon Cameroon : 20-23 Jav, Cameroon
> * PythonFOSDEM : 4-5 Feb, Belgium
> * PyCon Colombia : 10-12 Feb, Colombia
> * PyCon Pune : 16-20 Feb, India
> * Swiss Python Summit : 17-18 Feb, Switzerland
> * IrPyCon : 17-18 Feb, Iran
> * PyCon SK : 10-13 Mar, Slovakia
> * Django Europe : 3-8 Apr, Italy
> * PyCon Otto : 6-9 Apr, Italy
> * Python Sudeste : 5-7 Mai, Brazil
> * GeoPython : 8-11 May, Switzerland
> * PyCon US : 17-26 May, USA
> * EuroPython : July, Italy
> * PyCon AU : 3-9 Aug, Australia
> * PyCon UK : September, United Kingdom
> * PyCon CA : November, Canada
> * PyCon Ireland : October, Ireland
> * PyCon FR : October/November, France
>
> And you ?
> Please, could you check on https://www.python.org/events/ , if you are an
> organizer, please add your event.
>
> If you think there is a missing event, please, send me the info via
> [email](mailto:stephane at wirtel.be) or via my [twitter
> account](https://twitter.com/matrixise) and I will add it on my slides.
>
> I would like to present your event.
>
> Thank you so much for your help.
>
> Stephane Wirtel
>
> [1] https://www.python-fosdem.org
>
> --
> St?phane Wirtel - http://wirtel.be - @matrixise
> _______________________________________________
> PSF-Community mailing list
> PSF-Community at python.org
> https://mail.python.org/mailman/listinfo/psf-community



-- 
Kind regards,

Danny W. Adair


From no.email at nospam.invalid  Mon Jan  9 16:16:25 2017
From: no.email at nospam.invalid (Paul Rubin)
Date: Mon, 09 Jan 2017 13:16:25 -0800
Subject: Temporary variables in list comprehensions
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
 <o4vpd4$nuu$1@blaine.gmane.org>
 <mailman.372.1483958517.2395.python-list@python.org>
 <871swc1pez.fsf@nightsong.com>
 <20170109061531.71e3c795@bigbox.christie.dr>
 <mailman.376.1483964642.2395.python-list@python.org>
Message-ID: <87tw98ylw6.fsf@nightsong.com>

Tim Chase <python.list at tim.thechases.com> writes:
>> result = [(tmp, tmp+1) for tmp in map(expensive_calculation, data)]
>
> As charmingly expressive as map() is, the wildly different behavior in
> py3 (it's a generator that evaluates lazily) vs py2 (it consumes the
> entire iterable in one go) leads me to avoid it in general,

Well, there's itertools.imap which maps lazily in py2.



From python at deborahswanson.net  Mon Jan  9 16:40:47 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 9 Jan 2017 13:40:47 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <o50811$cnn$1@blaine.gmane.org>
Message-ID: <003c01d26ac1$0a358e00$27b23dae@sambora>

Peter Otten wrote, on January 09, 2017 6:51 AM
> 
> Deborah Swanson wrote:
> 
> > Even better, to get hold of all the records with the same
Description 
> > as the current row, compare them all, mark all but the different
ones 
> > for deletion, and then resume processing the records after the last 
> > one?
> 
> When you look at all fields for deduplication anyway there's no need
to 
> treat one field (Description) specially. Just
> 
> records = set(records)

I haven't worked with sets before, so this would be a good time to
start.

> should be fine. As the initial order is lost* you probably want to
sort 
> afterwards. The code then becomes
> 
> records = sorted(
>     set(records), 
>     key=operator.attrgetter("Description")
> )

Good, this is confirmation that 'sorted()' is the way to go. I want a 2
key sort, Description and Date, but I think I can figure out how to do
that.


> Now if you want to fill in missing values, you should probably do this

> before deduplication 

That's how my original code was written, to fill in missing values as
the very last thing before saving to csv.

> -- and the complete() function introduced in
>https://mail.python.org/pipermail/python-list/2016-December/717847.html

> can be adapted to work with namedtuples instead of dicts.

Ah, your defaultdict suggestion. Since my original comprows() function
to fill in missing values is now broken after the rest of the code was
rewritten for namedtuples (I just commented it out to test the
namedtuples version), this would be a good time to look at defaultdict.

> (*) If you want to preserve the initial order you can use a 
> collections.OrderedDict instead of the set.

OrderedDict is another thing I haven't used, but would love to, so I
think I'll try both the set and the OrderedDict, and see which one is
best here.

Thanks again Peter, all your help is very much appreciated.

Deborah



From python at deborahswanson.net  Mon Jan  9 16:52:01 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 9 Jan 2017 13:52:01 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <51c2cf13-b516-4ebf-8ca9-a915520adcab@googlegroups.com>
Message-ID: <003d01d26ac2$9c17f0a0$27b23dae@sambora>

breamoreboy at gmail.com wrote, on January 09, 2017 8:32 AM
> 
> On Monday, January 9, 2017 at 2:22:19 PM UTC, Tim Chase wrote:
> > On 2017-01-08 22:58, Deborah Swanson wrote:
> > > 1) I have a section that loops through the sorted data, compares
two 
> > > adjacent rows at a time, and marks one of them for deletion if the

> > > rows are identical.
> > > and my question is whether there's a way to work with two adjacent

> > > rows without using subscripts?
> > 
> > I usually wrap the iterable in something like
> > 
> >   def pairwise(it):
> >     prev = next(it)
> >     for thing in it:
> >       yield prev, thing
> >       prev = thing
> > 
> >   for prev, cur in pairwise(records):
> >     compare(prev, cur)
> > 
> > which I find makes it more readable.
> > 
> > -tkc
> 
> Or from 
> https://docs.python.org/3/library/itertools.ht> ml#itertools-recipes:-
> 
> def pairwise(iterable):
>     "s -> (s0,s1), (s1,s2), (s2, s3), ..."
>     a, b = tee(iterable)
>     next(b, None)
>     return zip(a, b)
> 
> This and many other recipes are available in the 
> more-itertools module which is on pypi.

Thanks, I'll keep this since I seem to do pairwise comparisons a lot.
I'm going to try using set or OrderedDict for the current problem, per
Peter's suggestion, but if I can't make that work, this surely will.



From python at deborahswanson.net  Mon Jan  9 16:56:04 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 9 Jan 2017 13:56:04 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <20170109082143.6b0a019f@bigbox.christie.dr>
Message-ID: <003e01d26ac3$2d1036d0$27b23dae@sambora>

Tim Chase wrote, on January 09, 2017 6:22 AM
> 
> On 2017-01-08 22:58, Deborah Swanson wrote:
> > 1) I have a section that loops through the sorted data, compares two

> > adjacent rows at a time, and marks one of them for deletion if the 
> > rows are identical.
> > and my question is whether there's a way to work with two adjacent 
> > rows without using subscripts?
> 
> I usually wrap the iterable in something like
> 
>   def pairwise(it):
>     prev = next(it)
>     for thing in it:
>       yield prev, thing
>       prev = thing
> 
>   for prev, cur in pairwise(records):
>     compare(prev, cur)
> 
> which I find makes it more readable.
> 
> -tkc

This looks very useful, and comparing two adjacent rows is something I
do often. Thanks Tim!

Deborah



From breamoreboy at gmail.com  Mon Jan  9 17:16:41 2017
From: breamoreboy at gmail.com (breamoreboy at gmail.com)
Date: Mon, 9 Jan 2017 14:16:41 -0800 (PST)
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <mailman.400.1483983236.2395.python-list@python.org>
References: <o4tebf$al7$1@blaine.gmane.org>
 <003301d26a45$cc04a5b0$27b23dae@sambora>
 <20170109082143.6b0a019f@bigbox.christie.dr>
 <mailman.386.1483971726.2395.python-list@python.org>
 <51c2cf13-b516-4ebf-8ca9-a915520adcab@googlegroups.com>
 <20170109110830.42cb734e@bigbox.christie.dr>
 <mailman.400.1483983236.2395.python-list@python.org>
Message-ID: <2ba0c533-b586-4865-a524-2ee0aaff14ad@googlegroups.com>

On Monday, January 9, 2017 at 5:34:12 PM UTC, Tim Chase wrote:
> On 2017-01-09 08:31, breamoreboy wrote:
> > On Monday, January 9, 2017 at 2:22:19 PM UTC, Tim Chase wrote:
> > > I usually wrap the iterable in something like
> > > 
> > >   def pairwise(it):
> > >     prev = next(it)
> > >     for thing in it:
> > >       yield prev, thing
> > >       prev = thing
> > 
> > Or from
> > https://docs.python.org/3/library/itertools.html#itertools-recipes:-
> > 
> > def pairwise(iterable):
> >     "s -> (s0,s1), (s1,s2), (s2, s3), ..."
> >     a, b = tee(iterable)
> >     next(b, None)
> >     return zip(a, b)
> > 
> > This and many other recipes are available in the more-itertools
> > module which is on pypi. 
> 
> Ah, helpful to not have to do it from scratch each time.  Also, I see
> several others that I've coded up from scratch (particularly the
> partition() and first_true() functions).
> 
> I usually want to make sure it's tailored for my use cases. The above
> pairwise() is my most common use case, but I occasionally want N-wise
> pairing

def ntuplewise(iterable, n=2):
    args = tee(iterable, n)
    loops = n - 1
    while loops:
        for _ in range(loops):
            next(args[loops], None)
        loops -= 1
    return zip(*args)

> 
>   s -> (s0,s1,?sN), (s1,s2,?S{N+1}), (s2,s3,?s{N+2}), ?
> 
> or to pad them out so either the leader/follower gets *all* of the
> values, with subsequent values being a padding value:
> 
>   # lst = [s0, s1, s2]
>   (s0,s1), (s1, s2), (s2, PADDING)

Use zip_longest instead of zip in the example code above.

>   # or
>   (PADDING, s0), (s0, s1), (s1, s2)

Haven't a clue off of the top of my head and I'm too darn tired to think about it :)

> 
> but it's good to have my common cases already coded & tested.
> 
> -tkc

Kindest regards.

Mark Lawrence.


From rhodri at kynesim.co.uk  Mon Jan  9 17:28:00 2017
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Mon, 9 Jan 2017 22:28:00 +0000
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <003c01d26ac1$0a358e00$27b23dae@sambora>
References: <003c01d26ac1$0a358e00$27b23dae@sambora>
Message-ID: <43063cff-c970-3221-96bc-11b6d8638e9e@kynesim.co.uk>

On 09/01/17 21:40, Deborah Swanson wrote:
> Peter Otten wrote, on January 09, 2017 6:51 AM
>>
>> records = sorted(
>>     set(records),
>>     key=operator.attrgetter("Description")
>> )
>
> Good, this is confirmation that 'sorted()' is the way to go. I want a 2
> key sort, Description and Date, but I think I can figure out how to do
> that.

There's a handy trick that you can use because the sorting algorithm is 
stable.  First, sort on your secondary key.  This will leave the data in 
the wrong order, but objects with the same primary key will be in the 
right order by secondary key relative to each other.

Then sort on your primary key.  Because the sorting algorithm is stable, 
it won't disturb the relative order of objects with the same primary 
key, giving you the sort that you want!

So assuming you want your data sorted by date, and then by description 
within the same date, it's just:

records = sorted(
     sorted(
         set(records),
         key=operator.attrgetter("Description")
     ),
     key=operator.attrgetter("Date")
)

-- 
Rhodri James *-* Kynesim Ltd


From python at deborahswanson.net  Mon Jan  9 17:33:12 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 9 Jan 2017 14:33:12 -0800
Subject: Clickable hyperlinks
In-Reply-To: <20170109075313.583d49e2@bigbox.christie.dr>
Message-ID: <004601d26ac8$5cdbfc50$27b23dae@sambora>

Tim Chase wrote, on January 09, 2017 5:53 AM
> 
> On 2017-01-09 05:00, Deborah Swanson wrote:
> > Code does in fact have the power to control what happens
> > in the console. How do you think Linux does it on their terminals
with 
> > clickable links? Granted, the code may have to specify parameters
for 
> > a particular console, but I certainly wasn't asking for universal
code 
> > that would work with any console.
> 
> Only to a degree.  Some consoles sniff the text sent to them 
> for particular URL-like patterns and linkify them for you.  
> All you have to do is print a URL that its pattern-matching 
> identifies:
> 
>   print("http://example.com")
> 
> However, as Rhodri details, *this is a feature of the 
> terminal emulator*. I've got a smattering of terminal 
> emulators at my disposal and many don't auto-linkify (xterm, 
> rxvt, the base non-X terminal) while others do (Gnome 
> terminal).  And in the ones where it doesn't work, it's 
> because it's the *terminal* that doesn't support linkifying, 
> so no amount of work on the application's part will make it linkify.

Ok, here is the crux of this thread's communication problem. I didn't
ask, or particularly care for all these lectures on the technology of
terminal emulators. I asked how to code Python to make clickable links.

Since all of you are quite obviously passionate about terminal
emulators, I would suggest that you start your own thread. Except that
it would have nothing to do with Python, and would be OT for this list.
What you're doing instead is thread jacking, hijacking a thread to talk
about a different topic. And in every list I've ever been on, thread
jacking is considered to be very rude. And it's also confusing if the
two topics are similar, which is exactly what happened here.

> > The console is a dead thing, it has no mind or soul to choose 
> > anything. Surely an educated person would know that.
> 
> Pretty much every quality system administrator I know uses 
> the terminal.  Just about all of the best devs I know use the 
> terminal. Microsoft added Powershell because of demand. They 
> added Ubuntu/bash support because of demand.  It allows for 
> powerful automation that would otherwise require writing 
> full-fledged scripts.  There is nothing dead about it.
> 
> I'm not sure where you get your baseless claim that "an 
> educated person would know that", since someone who had taken 
> the time to study the state of terminal use would see that is 
> far from dead.
> 
> -tkc

You are an ardently passionate and loyal bunch, aren't you.

I wasn't using "dead" in the figurative sense of no longer in use, I was
using it literally, as I clarified by saying "it has no mind or soul to
choose anything". A console (or terminal) is not a living thing with a
brain and consciousness, and its only capacity to choose anything is
dictated by the conditionals programmed into it. I've never heard of a
console (or terminal) that could choose to respond to some clicks and
not to others, have you? No, consoles have no minds of their own to
choose anything. This is what "an educated person would know" means in
the sentence I wrote.

It's not a good practice to twist other people's words to mean what you
want them to mean, while ignoring what they meant by them. Though it is
a convenient way to invent an argument where there is none, and that's
exactly what's happened here.



From ben.usenet at bsb.me.uk  Mon Jan  9 18:11:18 2017
From: ben.usenet at bsb.me.uk (Ben Bacarisse)
Date: Mon, 09 Jan 2017 23:11:18 +0000
Subject: Temporary variables in list comprehensions
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <87vatnvnft.fsf@bsb.me.uk>

Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:

> Suppose you have an expensive calculation that gets used two or more times in a 
> loop. The obvious way to avoid calculating it twice in an ordinary loop is with 
> a temporary variable:
>
> result = []
> for x in data:
>     tmp = expensive_calculation(x)
>     result.append((tmp, tmp+1))
>
>
> But what if you are using a list comprehension? Alas, list comps don't let you 
> have temporary variables, so you have to write this:
>
>
> [(expensive_calculation(x), expensive_calculation(x) + 1) for x in data]
>
>
> Or do you? ... no, you don't!
>
>
> [(tmp, tmp + 1) for x in data for tmp in [expensive_calculation(x)]]
>
>
> I can't decide whether that's an awesome trick or a horrible hack...

Nor I (but then I'm not really a Pythonista).  However I would use a
lambda as the natural way to create a local binding:

  [(lambda tmp: (tmp, tmp+1))(expensive_calculation(x)) for x in data]

-- 
Ben.


From __peter__ at web.de  Mon Jan  9 18:27:20 2017
From: __peter__ at web.de (Peter Otten)
Date: Tue, 10 Jan 2017 00:27:20 +0100
Subject: Using namedtuples field names for column indices in a list of
 lists
References: <003c01d26ac1$0a358e00$27b23dae@sambora>
 <43063cff-c970-3221-96bc-11b6d8638e9e@kynesim.co.uk>
Message-ID: <o5168k$6b2$1@blaine.gmane.org>

Rhodri James wrote:

> On 09/01/17 21:40, Deborah Swanson wrote:
>> Peter Otten wrote, on January 09, 2017 6:51 AM
>>>
>>> records = sorted(
>>>     set(records),
>>>     key=operator.attrgetter("Description")
>>> )
>>
>> Good, this is confirmation that 'sorted()' is the way to go. I want a 2
>> key sort, Description and Date, but I think I can figure out how to do
>> that.
> 
> There's a handy trick that you can use because the sorting algorithm is
> stable.  First, sort on your secondary key.  This will leave the data in
> the wrong order, but objects with the same primary key will be in the
> right order by secondary key relative to each other.
> 
> Then sort on your primary key.  Because the sorting algorithm is stable,
> it won't disturb the relative order of objects with the same primary
> key, giving you the sort that you want!
> 
> So assuming you want your data sorted by date, and then by description
> within the same date, it's just:
> 
> records = sorted(
>      sorted(
>          set(records),
>          key=operator.attrgetter("Description")
>      ),
>      key=operator.attrgetter("Date")
> )

While stable sort is nice in this case you can just say

key=operator.attrgetter("Description", "Date")

Personally I'd only use sorted() once and then switch to the sort() method.




From __peter__ at web.de  Mon Jan  9 19:09:46 2017
From: __peter__ at web.de (Peter Otten)
Date: Tue, 10 Jan 2017 01:09:46 +0100
Subject: Using namedtuples field names for column indices in a list of
 lists
References: <o4tebf$al7$1@blaine.gmane.org>
 <003301d26a45$cc04a5b0$27b23dae@sambora>
 <20170109082143.6b0a019f@bigbox.christie.dr>
 <mailman.386.1483971726.2395.python-list@python.org>
 <51c2cf13-b516-4ebf-8ca9-a915520adcab@googlegroups.com>
 <20170109110830.42cb734e@bigbox.christie.dr>
 <mailman.400.1483983236.2395.python-list@python.org>
 <2ba0c533-b586-4865-a524-2ee0aaff14ad@googlegroups.com>
Message-ID: <o518o6$ht$1@blaine.gmane.org>

breamoreboy at gmail.com wrote:

> On Monday, January 9, 2017 at 5:34:12 PM UTC, Tim Chase wrote:
>> On 2017-01-09 08:31, breamoreboy wrote:
>> > On Monday, January 9, 2017 at 2:22:19 PM UTC, Tim Chase wrote:
>> > > I usually wrap the iterable in something like
>> > > 
>> > >   def pairwise(it):
>> > >     prev = next(it)
>> > >     for thing in it:
>> > >       yield prev, thing
>> > >       prev = thing
>> > 
>> > Or from
>> > https://docs.python.org/3/library/itertools.html#itertools-recipes:->> > 
>> > def pairwise(iterable):
>> >     "s -> (s0,s1), (s1,s2), (s2, s3), ..."
>> >     a, b = tee(iterable)
>> >     next(b, None)
>> >     return zip(a, b)
>> > 
>> > This and many other recipes are available in the more-itertools
>> > module which is on pypi.
>> 
>> Ah, helpful to not have to do it from scratch each time.  Also, I see
>> several others that I've coded up from scratch (particularly the
>> partition() and first_true() functions).
>> 
>> I usually want to make sure it's tailored for my use cases. The above
>> pairwise() is my most common use case, but I occasionally want N-wise
>> pairing
> 
> def ntuplewise(iterable, n=2):
>     args = tee(iterable, n)
>     loops = n - 1
>     while loops:
>         for _ in range(loops):
>             next(args[loops], None)
>         loops -= 1
>     return zip(*args)
> 
>> 
>>   s -> (s0,s1,?sN), (s1,s2,?S{N+1}), (s2,s3,?s{N+2}), ?
>> 
>> or to pad them out so either the leader/follower gets *all* of the
>> values, with subsequent values being a padding value:
>> 
>>   # lst = [s0, s1, s2]
>>   (s0,s1), (s1, s2), (s2, PADDING)
> 
> Use zip_longest instead of zip in the example code above.
> 
>>   # or
>>   (PADDING, s0), (s0, s1), (s1, s2)
> 
> Haven't a clue off of the top of my head and I'm too darn tired to think
> about it :)

In both cases modify the iterable before feeding it to ntuplewise():

>>> PADDING = None
>>> N = 3
>>> items = range(5)
>>> list(ntuplewise(chain(repeat(PADDING, N-1), items), N))
[(None, None, 0), (None, 0, 1), (0, 1, 2), (1, 2, 3), (2, 3, 4)]
>>> list(ntuplewise(chain(items, repeat(PADDING, N-1)), N))
[(0, 1, 2), (1, 2, 3), (2, 3, 4), (3, 4, None), (4, None, None)]




From larry.martell at gmail.com  Mon Jan  9 19:10:59 2017
From: larry.martell at gmail.com (Larry Martell)
Date: Mon, 9 Jan 2017 19:10:59 -0500
Subject: Clickable hyperlinks
In-Reply-To: <004601d26ac8$5cdbfc50$27b23dae@sambora>
References: <20170109075313.583d49e2@bigbox.christie.dr>
 <004601d26ac8$5cdbfc50$27b23dae@sambora>
Message-ID: <CACwCsY5VpD4MpZZpRp4SHxWiFVHiVE0usv=kuDN7n4BFj4gsMg@mail.gmail.com>

On Mon, Jan 9, 2017 at 5:33 PM, Deborah Swanson
<python at deborahswanson.net> wrote:
> Ok, here is the crux of this thread's communication problem. I didn't
> ask, or particularly care for all these lectures on the technology of
> terminal emulators. I asked how to code Python to make clickable links.
>
> Since all of you are quite obviously passionate about terminal
> emulators, I would suggest that you start your own thread. Except that
> it would have nothing to do with Python, and would be OT for this list.
> What you're doing instead is thread jacking, hijacking a thread to talk
> about a different topic. And in every list I've ever been on, thread
> jacking is considered to be very rude. And it's also confusing if the
> two topics are similar, which is exactly what happened here.

Once you start a thread and put it out in the ether, it takes on a
life of its own, and cannot be controlled by anyone. That is true more
on this list then any other of the 100's I've been on. And it's why I
love it here.


From python at deborahswanson.net  Mon Jan  9 19:54:06 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 9 Jan 2017 16:54:06 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <o5168k$6b2$1@blaine.gmane.org>
Message-ID: <006901d26adc$0bc07f80$27b23dae@sambora>

Peter Otten wrote, on January 09, 2017 3:27 PM
> 
> While stable sort is nice in this case you can just say
> 
> key=operator.attrgetter("Description", "Date")
> 
> Personally I'd only use sorted() once and then switch to the 
> sort() method.

This works perfectly, thank you.

As I read the docs, the main (only?) difference between sorted() and
.sort() is that .sort() sorts the list in place.

Since I won't change the order of the records again after the sort, I'm
using 

records.sort(key=operator.attrgetter("Description", "Date"))

once, which also works perfectly.

So both sorted() and sort() can be used to sort namedtuples.  Good to
know!



From python at deborahswanson.net  Mon Jan  9 20:02:57 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 9 Jan 2017 17:02:57 -0800
Subject: Clickable hyperlinks
In-Reply-To: <CACwCsY5VpD4MpZZpRp4SHxWiFVHiVE0usv=kuDN7n4BFj4gsMg@mail.gmail.com>
Message-ID: <007101d26add$48752880$27b23dae@sambora>

Larry Martell wrote, on January 09, 2017 4:11 PM
> 
> On Mon, Jan 9, 2017 at 5:33 PM, Deborah Swanson 
> <python at deborahswanson.net> wrote:
> > Ok, here is the crux of this thread's communication problem. I
didn't 
> > ask, or particularly care for all these lectures on the technology
of 
> > terminal emulators. I asked how to code Python to make clickable
links.
> >
> > Since all of you are quite obviously passionate about terminal 
> > emulators, I would suggest that you start your own thread. Except
that 
> > it would have nothing to do with Python, and would be OT for this 
> > list. What you're doing instead is thread jacking, hijacking a
thread 
> > to talk about a different topic. And in every list I've ever been
on, 
> > thread jacking is considered to be very rude. And it's also
confusing 
> > if the two topics are similar, which is exactly what happened here.
> 
> Once you start a thread and put it out in the ether, it takes 
> on a life of its own, and cannot be controlled by anyone. 
> That is true more on this list then any other of the 100's 
> I've been on. And it's why I love it here.

Fair enough. I only suggested that they could have started their own
thread, but mainly just to point out that they would have been off-topic
if they did. I didn't demand that they do so, I just wanted them to
think about it.

I also prefer a loosely controlled list, and a freewheeling list is
ideal, but it only works well if people exercise basic politeness and
common sense.



From torriem at gmail.com  Mon Jan  9 20:33:28 2017
From: torriem at gmail.com (Michael Torrie)
Date: Mon, 9 Jan 2017 18:33:28 -0700
Subject: Clickable hyperlinks
In-Reply-To: <007101d26add$48752880$27b23dae@sambora>
References: <007101d26add$48752880$27b23dae@sambora>
Message-ID: <16bf1e18-1ab8-5f5f-1942-727949476a70@gmail.com>

On 01/09/2017 06:02 PM, Deborah Swanson wrote:
> Fair enough. I only suggested that they could have started their own
> thread, but mainly just to point out that they would have been off-topic
> if they did. I didn't demand that they do so, I just wanted them to
> think about it.

I don't see how it would be any more off-topic than your original query.
Which is to say, talking about Python's use of the console (beit a Win32
Console API window, a terminal emulator, or a PyCharm window) is on-topic.

> I also prefer a loosely controlled list, and a freewheeling list is
> ideal, but it only works well if people exercise basic politeness and
> common sense.

I agree.  Be aware that your own posts in this thread have bordered on
inflammatory on occasion.  Certainly your remark about "any educated
person would know that" could be taken in a very negative way.  I can't
remember everything I read in this thread, but I'm hard-pressed to find
examples where people were not polite to you, even though you pressed on
with certain lines of comment, especially when it was pointed out that
your question came from the wrong premise and idea of what the "console"
is.  I don't believe that someone pointing out flaws in your
understanding is inherently rude, though I think you took it as such.




From joel.goldstick at gmail.com  Mon Jan  9 20:42:39 2017
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Mon, 9 Jan 2017 20:42:39 -0500
Subject: Clickable hyperlinks
In-Reply-To: <16bf1e18-1ab8-5f5f-1942-727949476a70@gmail.com>
References: <007101d26add$48752880$27b23dae@sambora>
 <16bf1e18-1ab8-5f5f-1942-727949476a70@gmail.com>
Message-ID: <CAPM-O+xUFpeKkZqA1mdEsJiYGwgCUqH4R7x6tZeLYhktY5Oa5w@mail.gmail.com>

On Mon, Jan 9, 2017 at 8:33 PM, Michael Torrie <torriem at gmail.com> wrote:
> On 01/09/2017 06:02 PM, Deborah Swanson wrote:
>> Fair enough. I only suggested that they could have started their own
>> thread, but mainly just to point out that they would have been off-topic
>> if they did. I didn't demand that they do so, I just wanted them to
>> think about it.
>
> I don't see how it would be any more off-topic than your original query.
> Which is to say, talking about Python's use of the console (beit a Win32
> Console API window, a terminal emulator, or a PyCharm window) is on-topic.
>
>> I also prefer a loosely controlled list, and a freewheeling list is
>> ideal, but it only works well if people exercise basic politeness and
>> common sense.
>
> I agree.  Be aware that your own posts in this thread have bordered on
> inflammatory on occasion.  Certainly your remark about "any educated
> person would know that" could be taken in a very negative way.  I can't
> remember everything I read in this thread, but I'm hard-pressed to find
> examples where people were not polite to you, even though you pressed on
> with certain lines of comment, especially when it was pointed out that
> your question came from the wrong premise and idea of what the "console"
> is.  I don't believe that someone pointing out flaws in your
> understanding is inherently rude, though I think you took it as such.
>
>
> --
> https://mail.python.org/mailman/listinfo/python-list

Well put Michael

-- 
Joel Goldstick
http://joelgoldstick.com/blog
http://cc-baseballstats.info/stats/birthdays


From python at lucidity.plus.com  Mon Jan  9 20:47:00 2017
From: python at lucidity.plus.com (Erik)
Date: Tue, 10 Jan 2017 01:47:00 +0000
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <006901d26adc$0bc07f80$27b23dae@sambora>
References: <006901d26adc$0bc07f80$27b23dae@sambora>
Message-ID: <acc1130c-d4e3-e567-1a64-52097b97b691@lucidity.plus.com>

On 10/01/17 00:54, Deborah Swanson wrote:
> Since I won't change the order of the records again after the sort, I'm
> using
>
> records.sort(key=operator.attrgetter("Description", "Date"))
>
> once, which also works perfectly.
>
> So both sorted() and sort() can be used to sort namedtuples.  Good to
> know!

As people keep saying, the object you have called 'records' is a *list* 
of namedtuple objects. It is not a namedtuple.

IIRC, you create it using a list comprehension which creates the 
records. A list comprehension always creates a list.

The sorted() function and the list.sort() method can be used to sort a 
list containing any objects - it's just a case of telling them how to 
obtain the key values to compare (which, in the case of simple attribute 
access which the namedtuple objects allow, "operator.attrgetter()" will 
do that). This is why sorting the list works for you.

You could sort objects of different types - but you might need to supply 
a function instead of operator.attrgetter() which looks at the type of 
each object and returns something that's obtained differently for each 
type (but which the sort function can compare).




When you say 'Foo = namedtuple("Foo", "spam ham")', you are creating a 
"factory" which is able to generate "Foo" objects for you.

When you say "x = Foo(1, 2)" you are using the factory to create an 
object for you which has its "spam" and "ham" attributes set to the 
values 1 and 2 respectively.

When you say "records = [Foo(x, y) for x, y in some_iterable()]", you 
are creating a list of such objects. This is the thing you are then sorting.



Does that make sense?

Regards, E.


From python.list at tim.thechases.com  Mon Jan  9 21:37:15 2017
From: python.list at tim.thechases.com (Tim Chase)
Date: Mon, 9 Jan 2017 20:37:15 -0600
Subject: Temporary variables in list comprehensions
In-Reply-To: <87tw98ylw6.fsf@nightsong.com>
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
 <o4vpd4$nuu$1@blaine.gmane.org>
 <mailman.372.1483958517.2395.python-list@python.org>
 <871swc1pez.fsf@nightsong.com>
 <20170109061531.71e3c795@bigbox.christie.dr>
 <mailman.376.1483964642.2395.python-list@python.org>
 <87tw98ylw6.fsf@nightsong.com>
Message-ID: <20170109203715.1fa875a5@bigbox.christie.dr>

On 2017-01-09 13:16, Paul Rubin wrote:
> Tim Chase <python.list at tim.thechases.com> writes:
> >> result = [(tmp, tmp+1) for tmp in map(expensive_calculation,
> >> data)]
> >
> > As charmingly expressive as map() is, the wildly different
> > behavior in py3 (it's a generator that evaluates lazily) vs py2
> > (it consumes the entire iterable in one go) leads me to avoid it
> > in general,
> 
> Well, there's itertools.imap which maps lazily in py2.

Yes, but it's one of those things that I have to remember to
distinguish which one I use based on whether I'm working in py2 or
py3.  Meanwhile, using a generator expression is readable (my #1
reason for using Python is its readability) and works across 2 and 3
without changes or thinking about it further.  So that's what I tend
to use.

-tkc




From no.email at nospam.invalid  Mon Jan  9 21:57:21 2017
From: no.email at nospam.invalid (Paul Rubin)
Date: Mon, 09 Jan 2017 18:57:21 -0800
Subject: Temporary variables in list comprehensions
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
 <87vatnvnft.fsf@bsb.me.uk>
Message-ID: <87d1fvzkoe.fsf@nightsong.com>

Ben Bacarisse <ben.usenet at bsb.me.uk> writes:
>   [(lambda tmp: (tmp, tmp+1))(expensive_calculation(x)) for x in data]

Nice.  The Haskell "let" expression is implemented as syntax sugar for
that, I believe.


From python at deborahswanson.net  Mon Jan  9 22:02:59 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 9 Jan 2017 19:02:59 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <acc1130c-d4e3-e567-1a64-52097b97b691@lucidity.plus.com>
Message-ID: <007c01d26aee$0d76b5d0$27b23dae@sambora>

Erik wrote, on January 09, 2017 5:47 PM
> As people keep saying, the object you have called 'records' 
> is a *list* 
> of namedtuple objects. It is not a namedtuple.
> 
> IIRC, you create it using a list comprehension which creates the 
> records. A list comprehension always creates a list.

Well no. The list is created with:

records.extend(Record._make(row) for row in rows)

I'm new to both namedtuples and list comprehensions, so I'm not exactly
sure if this statement is a list comprehension. It looks like it could
be. In any case I recreated records in IDLE and got

>>> type(records)
<class 'list'>

So it's a class, derived from list? (Not sure what the 'list' means.)
'records' is in fact a class, it has an fget method and data members
that I've used. And it behaves like a list sometimes, but many times
not.

The only reason I've hedged away from advice to treat records as a list
for sorting until I tried it for myself, was because of an awful lot of
strange behavior I've seen, while trying to do the same things with
namedtuples as I routinely do with scalars and lists. This is all new,
and until now, unexplored territory for me. And I generally avoid saying
I'm sure or outright agreeing with something unless I really do know it.
 
> The sorted() function and the list.sort() method can be used 
> to sort a 
> list containing any objects - it's just a case of telling them how to 
> obtain the key values to compare (which, in the case of 
> simple attribute 
> access which the namedtuple objects allow, 
> "operator.attrgetter()" will 
> do that). This is why sorting the list works for you.
> 
> You could sort objects of different types - but you might 
> need to supply 
> a function instead of operator.attrgetter() which looks at 
> the type of 
> each object and returns something that's obtained differently 
> for each 
> type (but which the sort function can compare).
> 
> 
> 
> 
> When you say 'Foo = namedtuple("Foo", "spam ham")', you are 
> creating a 
> "factory" which is able to generate "Foo" objects for you.
> 
> When you say "x = Foo(1, 2)" you are using the factory to create an 
> object for you which has its "spam" and "ham" attributes set to the 
> values 1 and 2 respectively.
> 
> When you say "records = [Foo(x, y) for x, y in some_iterable()]", you 
> are creating a list of such objects. This is the thing you 
> are then sorting.
> 
> 
> 
> Does that make sense?
> 
> Regards, E.

Perfect sense. And now that I've confirmed in code that both sorted()
and 
.sort() behave as hoped for with namedtuples, I couldn't be happier.  ;)

The only thing I don't think you have 100% correct is your assertion
that records is a list. And I'm really not sure now that

records.extend(Record._make(row) for row in rows) 

is a list comprehension. 

That's the last statement in the creation of 'records', and immediately
after that statement executes, the type function says the resulting
'records' is a class, probably derived from list, but it's not a
straight up list.

'records' is enough different that you can't assume across the board
that namedtuples created this way are equivalent to a list. You do run
into problems if you assume it behaves like a list, or even like
standard tuples, because it doesn't always. Believe me, when I first
started working with namedtuples, I got plenty snarled up debugging code
that was written assuming list behavior to know that a namedtuple of
namedtuples is not exactly a list. Or even exactly like a list.

But that's just a quibble. The important thing in this context is that
both .sort() and sorted() treat it like a list and DTRT.  And that's
very nice. ;)

Deborah



From python.list at tim.thechases.com  Mon Jan  9 22:10:40 2017
From: python.list at tim.thechases.com (Tim Chase)
Date: Mon, 9 Jan 2017 21:10:40 -0600
Subject: Clickable hyperlinks
In-Reply-To: <004601d26ac8$5cdbfc50$27b23dae@sambora>
References: <20170109075313.583d49e2@bigbox.christie.dr>
 <004601d26ac8$5cdbfc50$27b23dae@sambora>
Message-ID: <20170109211040.3b09940e@bigbox.christie.dr>

On 2017-01-09 14:33, Deborah Swanson wrote:
> Ok, here is the crux of this thread's communication problem. I
> didn't ask, or particularly care for all these lectures on the
> technology of terminal emulators. I asked how to code Python to
> make clickable links.

The crux of the problem is that words mean things.  Specific words
have *specific* meanings.  When you say "make a clickable hyperlink
in a console", those words each have meanings.  Part of helping
people is coming to a common understanding.  In this case, the common
meaning is "I want to send some magical sequence to a terminal
emulator to make it treat the item as a clickable link."

To which anybody with experience in the matter answers exactly like
happened on the list:  that depends on your terminal emulator but is
entirely the domain of that emulator, and only within the context of
knowing which terminal emulator you're talking about, can any sort of
meaningful solution be given (if any).  You used words that carry a
particular technical meaning, but didn't use them in a way that made
much sense without taking the effort to clarify.

To round it out, you brought up your lengthy experience in the
computer field:

> I've only been online since 1992 (offline computing since 1972)

This usually suggests that you have been around enough to know that
these terms have precise meanings, and that you are wielding them in
the way others in the field use them.

So the roundabout discussion finally sussed out that you meant "I
want to send information to the PyCharm output area which I'm calling
a console (but is not necessarily an actual terminal emulator as the
technical word 'console' would usually be understood) and that output
area happens to know how to interpret some sequences as things that
are clickable.  How can I do that?"  Which then became "well, I don't
really even need to make clickable links, I just want to open some
target in a web browser."

And until folks on the list could understand your *intent* despite
the words you were using, it's a frustrating experience for all
involved.  So because of imprecise language, even if you didn't ask or
care about the terminology, *it matters if you want a viable answer*.


-tkc





From python at mrabarnett.plus.com  Mon Jan  9 22:37:01 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Tue, 10 Jan 2017 03:37:01 +0000
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <007c01d26aee$0d76b5d0$27b23dae@sambora>
References: <007c01d26aee$0d76b5d0$27b23dae@sambora>
Message-ID: <bda391e0-7660-a562-45f8-503eec1fe8cf@mrabarnett.plus.com>

On 2017-01-10 03:02, Deborah Swanson wrote:
> Erik wrote, on January 09, 2017 5:47 PM
>> As people keep saying, the object you have called 'records'
>> is a *list*
>> of namedtuple objects. It is not a namedtuple.
>>
>> IIRC, you create it using a list comprehension which creates the
>> records. A list comprehension always creates a list.
>
> Well no. The list is created with:
>
> records.extend(Record._make(row) for row in rows)
>
> I'm new to both namedtuples and list comprehensions, so I'm not exactly
> sure if this statement is a list comprehension. It looks like it could
> be.
 >
This is a list comprehension:

     [Record._make(row) for row in rows]

and this is a generator expression:

     (Record._make(row) for row in rows)

It needs the outer parentheses.

The .extend method will accept any iterable, including list comprehensions:

     records.extend([Record._make(row) for row in rows])

and generator expressions:

     records.extend((Record._make(row) for row in rows))

In the latter case, the generator expression is the only argument of the 
.extend method, and Python lets us drop the pair of parentheses:

     records.extend(Record._make(row) for row in rows)

If there were another argument, it would be ambiguous and Python would 
complain.

> In any case I recreated records in IDLE and got
>
>>>> type(records)
> <class 'list'>
>
> So it's a class, derived from list? (Not sure what the 'list' means.)
> 'records' is in fact a class, it has an fget method and data members
> that I've used. And it behaves like a list sometimes, but many times
> not.
>
Its type is 'list', so it's an instance of a list, i.e. it's a list!

> The only reason I've hedged away from advice to treat records as a list
> for sorting until I tried it for myself, was because of an awful lot of
> strange behavior I've seen, while trying to do the same things with
> namedtuples as I routinely do with scalars and lists. This is all new,
> and until now, unexplored territory for me. And I generally avoid saying
> I'm sure or outright agreeing with something unless I really do know it.
>
>> The sorted() function and the list.sort() method can be used
>> to sort a
>> list containing any objects - it's just a case of telling them how to
>> obtain the key values to compare (which, in the case of
>> simple attribute
>> access which the namedtuple objects allow,
>> "operator.attrgetter()" will
>> do that). This is why sorting the list works for you.
>>
>> You could sort objects of different types - but you might
>> need to supply
>> a function instead of operator.attrgetter() which looks at
>> the type of
>> each object and returns something that's obtained differently
>> for each
>> type (but which the sort function can compare).
>>
>>
>>
>>
>> When you say 'Foo = namedtuple("Foo", "spam ham")', you are
>> creating a
>> "factory" which is able to generate "Foo" objects for you.
>>
>> When you say "x = Foo(1, 2)" you are using the factory to create an
>> object for you which has its "spam" and "ham" attributes set to the
>> values 1 and 2 respectively.
>>
>> When you say "records = [Foo(x, y) for x, y in some_iterable()]", you
>> are creating a list of such objects. This is the thing you
>> are then sorting.
>>
>>
>>
>> Does that make sense?
>>
>> Regards, E.
>
> Perfect sense. And now that I've confirmed in code that both sorted()
> and
> .sort() behave as hoped for with namedtuples, I couldn't be happier.  ;)
>
> The only thing I don't think you have 100% correct is your assertion
> that records is a list. And I'm really not sure now that
>
> records.extend(Record._make(row) for row in rows)
>
> is a list comprehension.
>
> That's the last statement in the creation of 'records', and immediately
> after that statement executes, the type function says the resulting
> 'records' is a class, probably derived from list, but it's not a
> straight up list.
>
> 'records' is enough different that you can't assume across the board
> that namedtuples created this way are equivalent to a list. You do run
> into problems if you assume it behaves like a list, or even like
> standard tuples, because it doesn't always. Believe me, when I first
> started working with namedtuples, I got plenty snarled up debugging code
> that was written assuming list behavior to know that a namedtuple of
> namedtuples is not exactly a list. Or even exactly like a list.
>
> But that's just a quibble. The important thing in this context is that
> both .sort() and sorted() treat it like a list and DTRT.  And that's
> very nice. ;)
>
The list class has the .sort method, which sorts in-place. The 'sorted' 
function is a simple function that takes an iterable, iterates over it 
to build a list, sorts that list in-place, and then returns the list.

The oft-stated rule is that not every 2- or 3-line function needs to be 
a built-in, but 'sorted' is one of those cases where it's just nice to 
have it, a case of "practicality beats purity".



From ethan at stoneleaf.us  Mon Jan  9 23:00:47 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Mon, 09 Jan 2017 20:00:47 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <007c01d26aee$0d76b5d0$27b23dae@sambora>
References: <007c01d26aee$0d76b5d0$27b23dae@sambora>
Message-ID: <58745C6F.3020403@stoneleaf.us>

On 01/09/2017 07:02 PM, Deborah Swanson wrote:
> Erik wrote, on January 09, 2017 5:47 PM

>> As people keep saying, the object you have called 'records'
>> is a *list*
>> of namedtuple objects. It is not a namedtuple.
>>
>> IIRC, you create it using a list comprehension which creates the
>> records. A list comprehension always creates a list.
>
> Well no. The list is created with:
>
> records.extend(Record._make(row) for row in rows)
>
> I'm new to both namedtuples and list comprehensions, so I'm not exactly
> sure if this statement is a list comprehension. It looks like it could
> be. In any case I recreated records in IDLE and got
>
>--> type(records)
> <class 'list'>
>
> So it's a class, derived from list? (Not sure what the 'list' means.)

On the one hand, Deborah, I applaud your perseverance.  On the other, it seems as if you trying to run before you can walk.  I know tutorials can be boring, but you really should go through one so you have a basic understanding of the fundamentals.

Working in the REPL (the python console), we can see:

Python 3.4.0 (default, Apr 11 2014, 13:05:18)
...
--> type(list)
<class 'type'>
-->
--> type(list())
<class 'list'>
--> type([1, 2, 3])
<class 'list'>

So the `list` type is 'type', and the type of list instances is 'class list'.

Your records variable is an instance of a list filled with instances of a namedtuple, 'Record'.  One cannot sort a namedtuple, but one can sort a list of namedtuples -- which is what you are doing.

As I said earlier, I admire your persistence -- but take some time and learn the basic vocabulary as that will make it much easier for you to ask questions, and for us to give you meaningful answers.

--
~Ethan~


From python at lucidity.plus.com  Mon Jan  9 23:05:42 2017
From: python at lucidity.plus.com (Erik)
Date: Tue, 10 Jan 2017 04:05:42 +0000
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <007c01d26aee$0d76b5d0$27b23dae@sambora>
References: <007c01d26aee$0d76b5d0$27b23dae@sambora>
Message-ID: <21ae7283-b017-9181-7370-eb9b4678fe57@lucidity.plus.com>

On 10/01/17 03:02, Deborah Swanson wrote:
> Erik wrote, on January 09, 2017 5:47 PM
>> IIRC, you create it using a list comprehension which creates the
>> records. A list comprehension always creates a list.
>
> Well no. The list is created with:
>
> records.extend(Record._make(row) for row in rows)

No, the list is _extended_ by that code. The list is _created_ with a 
line that will say something like "records = []" or "records = list()" 
(or "records = <expression that yields a list>").

It's nice to see you agree that it's a list though. Oh, hold on ... ;)

> I'm not exactly
> sure if this statement is a list comprehension.

No, it's not. I was remembering an old message where someone suggested 
using the _make() method and that was expressed as a list comprehension.

What you have there is a call to list.extend() passing a _generator_ 
comprehension as its only parameter (which in this case you can consider 
to be equivalent to a list comprehension as all of the data are 
generated greedily). You see that I said "list.extend()". That's because 
'records' is a list.

>>>> type(records)
> <class 'list'>

Yes, it's an instance of the list class. A list object. A list.

 >>> type(list())
<class 'list'>
 >>> type([])
<class 'list'>
 >>> class foo: pass
...
 >>> type(foo())
<class '__main__.foo'>
 >>>

... type() will tell you what class your object is an instance of. 
"<class 'list'>" tells you that your object is a list.

> And it behaves like a list sometimes, but many times
> not.

I think that's impossible. I'm 100% sure it's a list. Please give an 
example of when 'records' does not behave like a list.

> The only thing I don't think you have 100% correct is your assertion
> that records is a list.

It's a list.

> But that's just a quibble. The important thing in this context is that
> both .sort() and sorted() treat it like a list and DTRT.

That's because it's a list :)

E.


From python at deborahswanson.net  Mon Jan  9 23:27:38 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 9 Jan 2017 20:27:38 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <bda391e0-7660-a562-45f8-503eec1fe8cf@mrabarnett.plus.com>
Message-ID: <008801d26af9$e0968ed0$27b23dae@sambora>

MRAB wrote, on January 09, 2017 7:37 PM
> 
> On 2017-01-10 03:02, Deborah Swanson wrote:
> > Erik wrote, on January 09, 2017 5:47 PM
> >> As people keep saying, the object you have called 'records' is a 
> >> *list* of namedtuple objects. It is not a namedtuple.
> >>
> >> IIRC, you create it using a list comprehension which creates the 
> >> records. A list comprehension always creates a list.
> >
> > Well no. The list is created with:
> >
> > records.extend(Record._make(row) for row in rows)
> >
> > I'm new to both namedtuples and list comprehensions, so I'm not 
> > exactly sure if this statement is a list comprehension. It 
> looks like 
> > it could be.
>  >
> This is a list comprehension:
> 
>      [Record._make(row) for row in rows]
> 
> and this is a generator expression:
> 
>      (Record._make(row) for row in rows)
> 
> It needs the outer parentheses.
> 
> The .extend method will accept any iterable, including list 
> comprehensions:
> 
>      records.extend([Record._make(row) for row in rows])
> 
> and generator expressions:
> 
>      records.extend((Record._make(row) for row in rows))
> 
> In the latter case, the generator expression is the only 
> argument of the 
> .extend method, and Python lets us drop the pair of parentheses:
> 
>      records.extend(Record._make(row) for row in rows)
> 
> If there were another argument, it would be ambiguous and 
> Python would 
> complain.

Appreciate your explanation of why this statement looks like a list
comprehension, but it isn't one.
 
> > In any case I recreated records in IDLE and got
> >
> >>>> type(records)
> > <class 'list'>
> >
> > So it's a class, derived from list? (Not sure what the 
> 'list' means.) 

>>> [1,2,3]
[1, 2, 3]
>>> type(_)
<class 'list'>

So it is a list, despite not being made by a list comprehension and
despite its non-listlike behaviors. Guess I've never looked at the type
of a list before, probably because lists are so obvious by looking at
them.

> > 'records' is in fact a class, it has an fget method and data members

> > that I've used. And it behaves like a list sometimes, but many times
not.
> >
> Its type is 'list', so it's an instance of a list, i.e. it's a list!

As testified by IDLE above!  ;)  A list of namedtuples may be an
instance of a list, but it doesn't always behave like a list of lists.
For example, if you want to modify an element of a record in records,
you can't just say 

'record.Location = Tulsa' 

like you can say 

'record[Location] = Tulsa'

because each record is very much like a tuple, and tuples are immutable.
You have to use the _replace function:

record._replace(Location) = Tulsa

This is very unlike a list of lists. Only the outer data structure is a
list, and inside it's all namedtuples.

So it's not a list of lists, it's a list of namedtuples.  But .sort and 
sorted() DTRT, and that's valuable.

> > The only reason I've hedged away from advice to treat records as a 
> > list for sorting until I tried it for myself, was because of an
awful 
> > lot of strange behavior I've seen, while trying to do the same
things 
> > with namedtuples as I routinely do with scalars and lists. This is
all 
> > new, and until now, unexplored territory for me. And I generally
avoid 
> > saying I'm sure or outright agreeing with something unless I really
do 
> > know it.
> >
> >> The sorted() function and the list.sort() method can be used to
sort 
> >> a list containing any objects - it's just a case of telling them
how 
> >> to obtain the key values to compare (which, in the case of
> >> simple attribute access which the namedtuple objects allow,
> >> "operator.attrgetter()" will
> >> do that). This is why sorting the list works for you.
> >>
> >> You could sort objects of different types - but you might need to 
> >> supply a function instead of operator.attrgetter() which looks at
> >> the type of
> >> each object and returns something that's obtained differently
> >> for each
> >> type (but which the sort function can compare).
> >>
> >>
> >>
> >>
> >> When you say 'Foo = namedtuple("Foo", "spam ham")', you 
> are creating 
> >> a "factory" which is able to generate "Foo" objects for you.
> >>
> >> When you say "x = Foo(1, 2)" you are using the factory to 
> create an 
> >> object for you which has its "spam" and "ham" attributes 
> set to the 
> >> values 1 and 2 respectively.
> >>
> >> When you say "records = [Foo(x, y) for x, y in 
> some_iterable()]", you 
> >> are creating a list of such objects. This is the thing you 
> are then 
> >> sorting.
> >>
> >>
> >>
> >> Does that make sense?
> >>
> >> Regards, E.
> >
> > Perfect sense. And now that I've confirmed in code that both
sorted() and
> > .sort() behave as hoped for with namedtuples, I couldn't be happier.

> > ;)
> >
> > The only thing I don't think you have 100% correct is your assertion

> > that records is a list. And I'm really not sure now that 
> > 
> > records.extend(Record._make(row) for row in rows)
> >
> > is a list comprehension.
> >
> > That's the last statement in the creation of 'records', and 
> > immediately after that statement executes, the type function says
the 
> > resulting 'records' is a class, probably derived from list, but it's

> > not a straight up list.
> >
> > 'records' is enough different that you can't assume across the board

> > that namedtuples created this way are equivalent to a list. You do
run 
> > into problems if you assume it behaves like a list, or even like 
> > standard tuples, because it doesn't always. Believe me, when I first

> > started working with namedtuples, I got plenty snarled up debugging 
> > code that was written assuming list behavior to know that a
namedtuple 
> > of namedtuples is not exactly a list. Or even exactly like a list.
> >
> > But that's just a quibble. The important thing in this context is
that 
> > both .sort() and sorted() treat it like a list and DTRT.  
> And that's very nice. ;)
> >
> The list class has the .sort method, which sorts in-place. The
'sorted' 
> function is a simple function that takes an iterable, iterates over it

> to build a list, sorts that list in-place, and then returns the list.
> 
> The oft-stated rule is that not every 2- or 3-line function needs to
be 
> a built-in, but 'sorted' is one of those cases where it's just nice to

> have it, a case of "practicality beats purity".
> 
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 



From steve+comp.lang.python at pearwood.info  Mon Jan  9 23:43:27 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Tue, 10 Jan 2017 15:43:27 +1100
Subject: Enum with only a single member
Message-ID: <58746671$0$11123$c3e8da3@news.astraweb.com>

Is it silly to create an enumeration with only a single member? That is, a 
singleton enum?

from enum import Enum

class Unique(Enum):
    FOO = auto()


The reason I ask is that I have two functions that take an enum argument. The 
first takes one of three enums:

class MarxBros(Enum):
    GROUCHO = 1
    CHICO = 2
    HARPO = 3

and the second takes *either* one of those three, or a fourth distinct value. 
So in my two functions, I have something like this:


def spam(arg):
    if isinstance(arg, MarxBros): 
        ...


def ham(arg):
    if isinstance(arg, MarxBros) or arg is Unique.FOO:
        ...


Good, bad or indifferent?



-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From python at deborahswanson.net  Mon Jan  9 23:51:44 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 9 Jan 2017 20:51:44 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <58745C6F.3020403@stoneleaf.us>
Message-ID: <008901d26afd$3e632200$27b23dae@sambora>

Ethan Furman wrote, on January 09, 2017 8:01 PM
> 
> On 01/09/2017 07:02 PM, Deborah Swanson wrote:
> > Erik wrote, on January 09, 2017 5:47 PM
> 
> >> As people keep saying, the object you have called 'records' is a 
> >> *list* of namedtuple objects. It is not a namedtuple.
> >>
> >> IIRC, you create it using a list comprehension which creates the 
> >> records. A list comprehension always creates a list.
> >
> > Well no. The list is created with:
> >
> > records.extend(Record._make(row) for row in rows)
> >
> > I'm new to both namedtuples and list comprehensions, so I'm not 
> > exactly sure if this statement is a list comprehension. It 
> looks like 
> > it could be. In any case I recreated records in IDLE and got
> >
> >--> type(records)
> > <class 'list'>
> >
> > So it's a class, derived from list? (Not sure what the 
> 'list' means.)
> 
> On the one hand, Deborah, I applaud your perseverance.  On 
> the other, it seems as if you trying to run before you can 
> walk.  I know tutorials can be boring, but you really should 
> go through one so you have a basic understanding of the fundamentals.

I actually have had a solid foundation of study in 2 terms of MIT's
introductory Python courses. But they can't cover everything in that
short a time.

> Working in the REPL (the python console), we can see:
> 
> Python 3.4.0 (default, Apr 11 2014, 13:05:18)
> ...
> --> type(list)
> <class 'type'>
> -->
> --> type(list())
> <class 'list'>
> --> type([1, 2, 3])
> <class 'list'>
> 
> So the `list` type is 'type', and the type of list instances 
> is 'class list'.

I just saw that while replying to MRAB. 'records' has type list, but
it's only the outer data structure that's a list. Inside, all the
records are namedtuples, and I think that accounts for behaviors that
are unlike a list of lists. (And the reason I was reluctant to accept
that it could be sorted until I tried it for myself.) The method calls I
was able to use were from the namedtuples, not the list of namedtuples.

> Your records variable is an instance of a list filled with 
> instances of a namedtuple, 'Record'.  One cannot sort a 
> namedtuple, but one can sort a list of namedtuples -- which 
> is what you are doing.

Yes, I think we've got that straight now.

> As I said earlier, I admire your persistence -- but take some 
> time and learn the basic vocabulary as that will make it much 
> easier for you to ask questions, and for us to give you 
> meaningful answers.
> 
> --
> ~Ethan~

As I mentioned, I have completed MIT's 2 introductory Python courses
with final grades of 98% and 97%.  What tutorials do you think would
significantly add to that introduction?

It's true that I didn't spend much time in the forums while I was taking
those courses, so this is the first time I've talked with people about
Python this intensively. But I'm a good learner and I'm picking up a lot
of it pretty quickly. People on the list also talk and comprehend
differently than people in the MIT courses did, so I have to become
accustomed to this as well. And the only place to learn that is right
here. 



From ethan at stoneleaf.us  Tue Jan 10 00:01:25 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Mon, 09 Jan 2017 21:01:25 -0800
Subject: Enum with only a single member
In-Reply-To: <58746671$0$11123$c3e8da3@news.astraweb.com>
References: <58746671$0$11123$c3e8da3@news.astraweb.com>
Message-ID: <58746AA5.7000107@stoneleaf.us>

On 01/09/2017 08:43 PM, Steven D'Aprano wrote:

> Is it silly to create an enumeration with only a single member? That is, a
> singleton enum?
>
> from enum import Enum
>
> class Unique(Enum):
>      FOO = auto()
>
>
> The reason I ask is that I have two functions that take an enum argument. The
> first takes one of three enums:
>
> class MarxBros(Enum):
>      GROUCHO = 1
>      CHICO = 2
>      HARPO = 3
>
> and the second takes *either* one of those three, or a fourth distinct value.
> So in my two functions, I have something like this:
>
>
> def spam(arg):
>      if isinstance(arg, MarxBros):
>          ...
>
>
> def ham(arg):
>      if isinstance(arg, MarxBros) or arg is Unique.FOO:
>          ...
>
>
> Good, bad or indifferent?

Well, the basic purpose of Enum is give meaningful names to otherwise magic constants, so while it certainly looks a bit unusual to have only one item in the enumeration, if that group naturally has only one item then sure, go for it!

--
~Ethan~


From python at deborahswanson.net  Tue Jan 10 00:03:04 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 9 Jan 2017 21:03:04 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <21ae7283-b017-9181-7370-eb9b4678fe57@lucidity.plus.com>
Message-ID: <008a01d26afe$d3fa7650$27b23dae@sambora>

Erik wrote, on January 09, 2017 8:06 PM
> 
> On 10/01/17 03:02, Deborah Swanson wrote:
> > Erik wrote, on January 09, 2017 5:47 PM
> >> IIRC, you create it using a list comprehension which creates the 
> >> records. A list comprehension always creates a list.
> >
> > Well no. The list is created with:
> >
> > records.extend(Record._make(row) for row in rows)
> 
> No, the list is _extended_ by that code. The list is _created_ with a 
> line that will say something like "records = []" or "records 
> = list()" 
> (or "records = <expression that yields a list>").

The list was created with this code:

    infile = open("E:\\Coding projects\\Pycharm\\Moving\\Moving 2017
in.csv")
    rows = csv.reader(infile)
    fieldnames = next(rows)
    Record = namedtuple("Record", fieldnames)
    records = [Record._make(fieldnames)]
    records.extend(Record._make(row) for row in rows)

I just pulled out the .extend statement to show you because that's what
looks like a list comprehension, but turns out not to be one.  We still
get a list though, on that we agree.  ;)
 
> It's nice to see you agree that it's a list though. Oh, hold on ... ;)
> 
> > I'm not exactly
> > sure if this statement is a list comprehension.
> 
> No, it's not. I was remembering an old message where someone 
> suggested 
> using the _make() method and that was expressed as a list 
> comprehension.
> 
> What you have there is a call to list.extend() passing a _generator_ 
> comprehension as its only parameter (which in this case you 
> can consider 
> to be equivalent to a list comprehension as all of the data are 
> generated greedily). You see that I said "list.extend()". 
> That's because 
> 'records' is a list.
> 
> >>>> type(records)
> > <class 'list'>
> 
> Yes, it's an instance of the list class. A list object. A list.
> 
>  >>> type(list())
> <class 'list'>
>  >>> type([])
> <class 'list'>
>  >>> class foo: pass
> ...
>  >>> type(foo())
> <class '__main__.foo'>
>  >>>
> 
> ... type() will tell you what class your object is an instance of. 
> "<class 'list'>" tells you that your object is a list.
> 
> > And it behaves like a list sometimes, but many times
> > not.
> 
> I think that's impossible. I'm 100% sure it's a list. Please give an 
> example of when 'records' does not behave like a list.

I gave an example in one of my last two replies to other people. The
thing is that it's a list, but it's not a list of lists. It's a list of
namedtuples, and the non-listlike behaviors appear when I'm directly
working with the namedtuples.

> > The only thing I don't think you have 100% correct is your assertion

> > that records is a list.
> 
> It's a list.

I agree, now. 
 
> > But that's just a quibble. The important thing in this context is
that 
> > both .sort() and sorted() treat it like a list and DTRT.
> 
> That's because it's a list :)
> 
> E.

It is!  A list of namedtuples that is, not a list of lists. sorted() and
.sort work because they only interact with the outer data structure,
which is a list.



From steve+comp.lang.python at pearwood.info  Tue Jan 10 00:18:09 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Tue, 10 Jan 2017 16:18:09 +1100
Subject: Is enum iteration order guaranteed?
Message-ID: <58746e93$0$1587$c3e8da3$5496439d@news.astraweb.com>

The docs say that enums can be iterated over, but it isn't clear to me whether 
they are iterated over in definition order or value order.

If I have:

class MarxBros(Enum):
    GROUCHO = 999
    CHICO = 5
    HARPO = 11
    ZEPPO = auto()
    GUMMO = -1

GROUCHO, CHICO, HARPO, ZEPPO, GUMMO = list(MarxBros)


is that guaranteed to do the right thing?

i.e. GROUCHO is MarxBros.GROUCHO, and similarly for the other members.




On that related note, how would people feel about a method that injects enums 
into the given namespace?

MarxBros._inject_(globals())

although maybe 

from MarxBros import *

would be more familiar syntax :-)





-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From jussi.piitulainen at helsinki.fi  Tue Jan 10 00:41:22 2017
From: jussi.piitulainen at helsinki.fi (Jussi Piitulainen)
Date: Tue, 10 Jan 2017 07:41:22 +0200
Subject: Enum with only a single member
References: <58746671$0$11123$c3e8da3@news.astraweb.com>
Message-ID: <lf5mvezeakd.fsf@ling.helsinki.fi>

Steven D'Aprano writes:

> Is it silly to create an enumeration with only a single member? That
> is, a singleton enum?
>
> from enum import Enum
>
> class Unique(Enum):
>     FOO = auto()
>
>
> The reason I ask is that I have two functions that take an enum
> argument. The first takes one of three enums:
>
> class MarxBros(Enum):
>     GROUCHO = 1
>     CHICO = 2
>     HARPO = 3
>
> and the second takes *either* one of those three, or a fourth distinct
> value. So in my two functions, I have something like this:
>
>
> def spam(arg):
>     if isinstance(arg, MarxBros): 
>         ...
>
>
> def ham(arg):
>     if isinstance(arg, MarxBros) or arg is Unique.FOO:
>         ...
>
>
> Good, bad or indifferent?

With a class of its own, the single value can be identified by its class
uniformly with the other relevant values.

def ham(arg):
    if insinstance(arg, (MarxBros, Unique)):
        ...

Seems good to me.


From ethan at stoneleaf.us  Tue Jan 10 00:55:10 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Mon, 09 Jan 2017 21:55:10 -0800
Subject: Is enum iteration order guaranteed?
In-Reply-To: <58746e93$0$1587$c3e8da3$5496439d@news.astraweb.com>
References: <58746e93$0$1587$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <5874773E.5040407@stoneleaf.us>

On 01/09/2017 09:18 PM, Steven D'Aprano wrote:

> The docs say that enums can be iterated over, but it isn't clear to me whether
> they are iterated over in definition order or value order.
>
> If I have:
>
> class MarxBros(Enum):
>      GROUCHO = 999
>      CHICO = 5
>      HARPO = 11
>      ZEPPO = auto()
>      GUMMO = -1
>
> GROUCHO, CHICO, HARPO, ZEPPO, GUMMO = list(MarxBros)

In Python 3 it is always definition order.  In Python 2 (using the enum34 [1] backport), the order is either by value if possible, or alphabetical  if not -- unless you use the _order_ attribute to set it:

class MarkBros(Enum):
     _order_ = 'GROUCHO CHICO HARGPO ZEPPO GUMMO'
     GROUCHO = 999
     ...

> On that related note, how would people feel about a method that injects enums
> into the given namespace?
>
> MarxBros._inject_(globals())
>
> although maybe
>
> from MarxBros import *
>
> would be more familiar syntax :-)

Or you can do globals().update(MarxBros.__members__).

--
~Ethan~


From ethan at stoneleaf.us  Tue Jan 10 01:05:52 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Mon, 09 Jan 2017 22:05:52 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <008901d26afd$3e632200$27b23dae@sambora>
References: <008901d26afd$3e632200$27b23dae@sambora>
Message-ID: <587479C0.7050401@stoneleaf.us>

On 01/09/2017 08:51 PM, Deborah Swanson wrote:
> Ethan Furman wrote, on January 09, 2017 8:01 PM

>> As I said earlier, I admire your persistence -- but take some
>> time and learn the basic vocabulary as that will make it much
>> easier for you to ask questions, and for us to give you
>> meaningful answers.
>
> As I mentioned, I have completed MIT's 2 introductory Python courses
> with final grades of 98% and 97%.  What tutorials do you think would
> significantly add to that introduction?

The Python version of "Think like a computer scientist" is good.  Otherwise, ask the list for recommendations.  I'm not suggesting more advanced topics, but rather basic topics such as how the REPL works, how to tell what objects you have, how to find the methods those objects have, etc.
  
> It's true that I didn't spend much time in the forums while I was taking
> those courses, so this is the first time I've talked with people about
> Python this intensively. But I'm a good learner and I'm picking up a lot
> of it pretty quickly. People on the list also talk and comprehend
> differently than people in the MIT courses did, so I have to become
> accustomed to this as well. And the only place to learn that is right
> here.

Indeed.

The issue I (and others) see, though, is more along the lines of basic understanding: you seemed to think that a list of lists should act the same as a list of tuples, even though lists and tuples are not the same thing.  It's like expecting a basket of oranges to behave like a basket of avocados. ;)

As you say, you're making good progress.

--
~Ethan~


From steve+comp.lang.python at pearwood.info  Tue Jan 10 01:22:34 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Tue, 10 Jan 2017 17:22:34 +1100
Subject: Is enum iteration order guaranteed?
References: <58746e93$0$1587$c3e8da3$5496439d@news.astraweb.com>
 <5874773E.5040407@stoneleaf.us>
 <mailman.439.1484027689.2395.python-list@python.org>
Message-ID: <58747dac$0$22142$c3e8da3$5496439d@news.astraweb.com>

On Tuesday 10 January 2017 16:55, Ethan Furman wrote:

> On 01/09/2017 09:18 PM, Steven D'Aprano wrote:
> 
>> The docs say that enums can be iterated over, but it isn't clear to me
>> whether they are iterated over in definition order or value order.
>>
>> If I have:
>>
>> class MarxBros(Enum):
>>      GROUCHO = 999
>>      CHICO = 5
>>      HARPO = 11
>>      ZEPPO = auto()
>>      GUMMO = -1
>>
>> GROUCHO, CHICO, HARPO, ZEPPO, GUMMO = list(MarxBros)
> 
> In Python 3 it is always definition order.

I only care about Python 3 for this.

Did I miss something in the docs, or should this be added?


[...]
>> On that related note, how would people feel about a method that injects
>> enums into the given namespace?
[...]
> Or you can do globals().update(MarxBros.__members__).

Sweet!



-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From python at deborahswanson.net  Tue Jan 10 02:14:16 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Mon, 9 Jan 2017 23:14:16 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <587479C0.7050401@stoneleaf.us>
Message-ID: <009501d26b11$281a3d30$27b23dae@sambora>

Ethan Furman wrote, on January 09, 2017 10:06 PM
> 
> On 01/09/2017 08:51 PM, Deborah Swanson wrote:
> > Ethan Furman wrote, on January 09, 2017 8:01 PM
> 
> >> As I said earlier, I admire your persistence -- but take some time 
> >> and learn the basic vocabulary as that will make it much easier for

> >> you to ask questions, and for us to give you meaningful answers.
> >
> > As I mentioned, I have completed MIT's 2 introductory Python courses

> > with final grades of 98% and 97%.  What tutorials do you think would

> > significantly add to that introduction?
> 
> The Python version of "Think like a computer scientist" is 
> good.  Otherwise, ask the list for recommendations.  I'm not 
> suggesting more advanced topics, but rather basic topics such 
> as how the REPL works, how to tell what objects you have, how 
> to find the methods those objects have, etc.

I'm working on all of that, and I've been taking physics, chem, computer
science and theoretical mathematics (straight 4.0s my last 2 years,
graduated summa cum laude), but it's been a couple of decades since my
last brick building university course. It's coming back fast, but
there's a lot I'm still pulling out of cobwebs. I basically know the
tools to use for the things you mention, but in the online coursework
I've done in the past year, we didn't need to use them because they told
us everything. So that's another thing I'm doing catch up on. Really
shouldn't take too long, it's not that complicated or difficult.

> > It's true that I didn't spend much time in the forums while I was 
> > taking those courses, so this is the first time I've talked with 
> > people about Python this intensively. But I'm a good learner and I'm

> > picking up a lot of it pretty quickly. People on the list also talk 
> > and comprehend differently than people in the MIT courses did, so I 
> > have to become accustomed to this as well. And the only place to
learn 
> > that is right here.
> 
> Indeed.
> 
> The issue I (and others) see, though, is more along the lines 
> of basic understanding: you seemed to think that a list of 
> lists should act the same as a list of tuples, even though 
> lists and tuples are not the same thing.  It's like expecting 
> a basket of oranges to behave like a basket of avocados. ;)
> 
> As you say, you're making good progress.
> 
> --
> ~Ethan~

I'm sorry, I didn't think a list of namedtuples would be like a list of
lists when I wrote to Erik just a bit ago today, but I sort of did when
I first started trying to use them a couple days ago. And to the extent
I was pretty sure they weren't the same, I still didn't know in what
ways they were different. So when people ask me questions about why I
did things the way I did, I try to explain that I didn't know certain
things then, but I know them now. I'm guessing that you (and those who
see things like you do) might not be used to working with quick learners
who make mistakes at first but catch up with them real fast, or you're
very judgemental about people who make mistakes, period. I certainly
don't care if you want to judge me, you're entitled to your opinion. One
of my MIT professors was always screwing up little things, even things
he knew inside out. Some people are like that, and I think I might be
one of them, although I'm really not as bad as he was.

So I guess you should just do your thing and I'll do mine. I don't
promise that I'll ever get to the point where I never set a foot wrong.
I know some people can do that, and I hope someday I will. But then I
remember the MIT professor, who I really learned a lot from, despite all
his flub-ups, and that I might be a little bit like him. Takes all
kinds, and I think in the end what will count is the quality of my
finished work (which has always been excellent), and not the messy
process to get there.

It shocked me the first time someone on this list jumped down my throat
for a momentary lapse on my part, as if I was a total idiot and knew
nothing, but I'm sort of getting used to that too. It must be nice to be
so perfect, I guess.

Deborah



From storchaka at gmail.com  Tue Jan 10 02:19:14 2017
From: storchaka at gmail.com (Serhiy Storchaka)
Date: Tue, 10 Jan 2017 09:19:14 +0200
Subject: Temporary variables in list comprehensions
In-Reply-To: <871swc1pez.fsf@nightsong.com>
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
 <o4vpd4$nuu$1@blaine.gmane.org>
 <mailman.372.1483958517.2395.python-list@python.org>
 <871swc1pez.fsf@nightsong.com>
Message-ID: <o521te$b04$1@blaine.gmane.org>

On 09.01.17 12:46, Paul Rubin wrote:
> Serhiy Storchaka <storchaka at gmail.com> writes:
>> gen = (expensive_calculation(x) for x in data)
>> result = [(tmp, tmp + 1) for tmp in gen]
>
> result = [(tmp, tmp+1) for tmp in map(expensive_calculation, data)]

Yes, of course, but only in the case of one-argument function 
expensive_calculation(). If this is just an expensive expression or need 
to pass multiple arguments to an expensive function, a generator 
expression could look simpler than a lambda or a local function.




From no.email at nospam.invalid  Tue Jan 10 03:33:32 2017
From: no.email at nospam.invalid (Paul Rubin)
Date: Tue, 10 Jan 2017 00:33:32 -0800
Subject: Enum with only a single member
References: <58746671$0$11123$c3e8da3@news.astraweb.com>
Message-ID: <878tqjz543.fsf@nightsong.com>

Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:
> Is it silly to create an enumeration with only a single member?

No.  

> That is, a singleton enum?

Why stop there?  You can make empty ones too.  (Zerotons?)

> The reason I ask is that I have two functions that take an enum
> argument. 

Sounds like a good reason.

> def spam(arg):
>     if isinstance(arg, MarxBros): 
> def ham(arg):
>     if isinstance(arg, MarxBros) or arg is Unique.FOO:

> Good, bad or indifferent?

Ummmm, that's ugly, but the alternatives are worse unless there's more
branches, and maybe even then.


From ethan at stoneleaf.us  Tue Jan 10 03:35:25 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 10 Jan 2017 00:35:25 -0800
Subject: Is enum iteration order guaranteed?
In-Reply-To: <58747dac$0$22142$c3e8da3$5496439d@news.astraweb.com>
References: <58746e93$0$1587$c3e8da3$5496439d@news.astraweb.com>
 <5874773E.5040407@stoneleaf.us>
 <mailman.439.1484027689.2395.python-list@python.org>
 <58747dac$0$22142$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <58749CCD.6080606@stoneleaf.us>

On 01/09/2017 10:22 PM, Steven D'Aprano wrote:
> On Tuesday 10 January 2017 16:55, Ethan Furman wrote:
>> On 01/09/2017 09:18 PM, Steven D'Aprano wrote:
>>
>>> The docs say that enums can be iterated over, but it isn't clear to me
>>> whether they are iterated over in definition order or value order.
>>>
>>> If I have:
>>>
>>> class MarxBros(Enum):
>>>       GROUCHO = 999
>>>       CHICO = 5
>>>       HARPO = 11
>>>       ZEPPO = auto()
>>>       GUMMO = -1
>>>
>>> GROUCHO, CHICO, HARPO, ZEPPO, GUMMO = list(MarxBros)
>>
>> In Python 3 it is always definition order.
>
> I only care about Python 3 for this.
>
> Did I miss something in the docs, or should this be added?

In https://docs.python.org/3/library/enum.html#creating-an-enum, fifth paragraph down:

   Enumerations support iteration, in definition order ...

--
~Ethan~


From rosuav at gmail.com  Tue Jan 10 03:37:08 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 10 Jan 2017 19:37:08 +1100
Subject: Enum with only a single member
In-Reply-To: <878tqjz543.fsf@nightsong.com>
References: <58746671$0$11123$c3e8da3@news.astraweb.com>
 <878tqjz543.fsf@nightsong.com>
Message-ID: <CAPTjJmotbSR57BYsvzmoWKSpKZ+-XtLPEoS-HCO-LLsO=E2FOQ@mail.gmail.com>

On Tue, Jan 10, 2017 at 7:33 PM, Paul Rubin <no.email at nospam.invalid> wrote:
>> That is, a singleton enum?
>
> Why stop there?  You can make empty ones too.  (Zerotons?)

Sure you *can*, but I can't think of any time they'd be useful. Can
you give an example?

ChrisA


From ethan at stoneleaf.us  Tue Jan 10 03:49:36 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 10 Jan 2017 00:49:36 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <009501d26b11$281a3d30$27b23dae@sambora>
References: <009501d26b11$281a3d30$27b23dae@sambora>
Message-ID: <5874A020.7070001@stoneleaf.us>

On 01/09/2017 11:14 PM, Deborah Swanson wrote:

> So I guess you should just do your thing and I'll do mine.

As you say.

> Takes all kinds, and I think in the end what will count is the quality of my
> finished work (which has always been excellent), and not the messy
> process to get there.

Agreed.

--
~Ethan~


From ethan at stoneleaf.us  Tue Jan 10 03:51:45 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 10 Jan 2017 00:51:45 -0800
Subject: Enum with only a single member
In-Reply-To: <CAPTjJmotbSR57BYsvzmoWKSpKZ+-XtLPEoS-HCO-LLsO=E2FOQ@mail.gmail.com>
References: <58746671$0$11123$c3e8da3@news.astraweb.com>
 <878tqjz543.fsf@nightsong.com>
 <CAPTjJmotbSR57BYsvzmoWKSpKZ+-XtLPEoS-HCO-LLsO=E2FOQ@mail.gmail.com>
Message-ID: <5874A0A1.3010707@stoneleaf.us>

On 01/10/2017 12:37 AM, Chris Angelico wrote:
> On Tue, Jan 10, 2017 at 7:33 PM, Paul Rubin wrote:

>>> That is, a singleton enum?
>>
>> Why stop there?  You can make empty ones too.  (Zerotons?)
>
> Sure you *can*, but I can't think of any time they'd be useful. Can
> you give an example?

Sure.  Any time you have some base behaviour you want shared amongst multiple Enum classes.  ;)

--
~Ethan~


From jeanmichel at sequans.com  Tue Jan 10 04:47:01 2017
From: jeanmichel at sequans.com (jmp)
Date: Tue, 10 Jan 2017 10:47:01 +0100
Subject: Enum with only a single member
In-Reply-To: <58746671$0$11123$c3e8da3@news.astraweb.com>
References: <58746671$0$11123$c3e8da3@news.astraweb.com>
Message-ID: <o52aih$md8$1@blaine.gmane.org>

On 01/10/2017 05:43 AM, Steven D'Aprano wrote:
> Is it silly to create an enumeration with only a single member? That is, a
> singleton enum?

Don't think so, for the same reason that lists with one element make sense.

> def ham(arg):
>      if isinstance(arg, MarxBros) or arg is Unique.FOO:
>          ...
>
>
> Good, bad or indifferent?
>


Though I'd write

def ham(arg):
   if arg in MarxBros or arg in Unique:
     ...


JM



From __peter__ at web.de  Tue Jan 10 04:52:26 2017
From: __peter__ at web.de (Peter Otten)
Date: Tue, 10 Jan 2017 10:52:26 +0100
Subject: Enum with only a single member
References: <58746671$0$11123$c3e8da3@news.astraweb.com>
Message-ID: <o52asm$qgr$1@blaine.gmane.org>

Steven D'Aprano wrote:

> Is it silly to create an enumeration with only a single member? That is, a
> singleton enum?
> 
> from enum import Enum
> 
> class Unique(Enum):
>     FOO = auto()
> 
> 
> The reason I ask is that I have two functions that take an enum argument.
> The first takes one of three enums:
> 
> class MarxBros(Enum):
>     GROUCHO = 1
>     CHICO = 2
>     HARPO = 3
> 
> and the second takes *either* one of those three, or a fourth distinct
> value. So in my two functions, I have something like this:
> 
> 
> def spam(arg):
>     if isinstance(arg, MarxBros):
>         ...
> 
> 
> def ham(arg):
>     if isinstance(arg, MarxBros) or arg is Unique.FOO:
>         ...
> 
> 
> Good, bad or indifferent?

I don't see a problem. As it looks like you cannot subclass Enum subclasses 
alternative spellings might be

isintance(args, (MarxBros, Unique))

or

BOTH = set(MarxBros) | set(Unique)
arg in MarxBros
arg in BOTH



From jeanmichel at sequans.com  Tue Jan 10 05:35:31 2017
From: jeanmichel at sequans.com (jmp)
Date: Tue, 10 Jan 2017 11:35:31 +0100
Subject: Temporary variables in list comprehensions
In-Reply-To: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <o52dde$iot$1@blaine.gmane.org>

On 01/09/2017 04:53 AM, Steven D'Aprano wrote:
> Suppose you have an expensive calculation that gets used two or more times in a
> loop. The obvious way to avoid calculating it twice in an ordinary loop is with
> a temporary variable:
>
> result = []
> for x in data:
>      tmp = expensive_calculation(x)
>      result.append((tmp, tmp+1))
>
>
> But what if you are using a list comprehension? Alas, list comps don't let you
> have temporary variables, so you have to write this:
>
>
> [(expensive_calculation(x), expensive_calculation(x) + 1) for x in data]
>
>
> Or do you? ... no, you don't!
>
>
> [(tmp, tmp + 1) for x in data for tmp in [expensive_calculation(x)]]
>
>
> I can't decide whether that's an awesome trick or a horrible hack...


In any situation, the double list comprehension (also used to flatten 
lists) is very difficult to read.

What about

for x in (f(d) for d in data):
    result.append(x, x+1)


There's a double for loop in the same line but the generator parenthesis 
help a lot. No lame tmp variable involved.

JM



From p.f.moore at gmail.com  Tue Jan 10 09:32:31 2017
From: p.f.moore at gmail.com (Paul Moore)
Date: Tue, 10 Jan 2017 06:32:31 -0800 (PST)
Subject: Temporary variables in list comprehensions
In-Reply-To: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <520ce11d-5549-4b87-911d-15fa91851218@googlegroups.com>

On Monday, 9 January 2017 03:53:37 UTC, Steven D'Aprano  wrote:
> Suppose you have an expensive calculation that gets used two or more times
> in a loop.

[...]

> [(tmp, tmp + 1) for x in data for tmp in [expensive_calculation(x)]]
> 
> I can't decide whether that's an awesome trick or a horrible hack...

My immediate reaction is that it depends on the constraints that made it important for you to use a comprehension rather than an explicit loop in the first place.

For a toy example like this it's obviously a horrible hack, and you should simply make an explicit loop:

    result = []
    for x in data:
      # Don't recalculate this value, as it's expensive!
      val = expensive_calculation(x)
      result.append((val, val+1))

In a real world case, maybe there's a good reason why you'd prefer to stick with a comprehension. In that case, you look at trade-offs like

    def intermediate_tuple(val): return val, val+1
    [intermediate_tuple(x) for x in data]

or

    [(lambda val: (val, val+1))(x) for x in data]

or your version.

All have their own unique uglinesses, as does the explicit loop. Personally my preferences would be the explicit loop, then the intermediate_tuple function, in that order.

Paul


From phd at phdru.name  Tue Jan 10 09:59:45 2017
From: phd at phdru.name (Oleg Broytman)
Date: Tue, 10 Jan 2017 15:59:45 +0100
Subject: Announcement: TLSv1.2 will become mandatory in the future for
 Python.org Sites
In-Reply-To: <1B1B29CD-AA4E-47C0-89A8-2748D5A14FC3@python.org>
References: <1B1B29CD-AA4E-47C0-89A8-2748D5A14FC3@python.org>
Message-ID: <20170110145945.GA2925@phdru.name>

On Tue, Jan 10, 2017 at 08:27:21AM -0500, Donald Stufft <donald at python.org> wrote:
>     python3 -c "import urllib.request,json; print(json.loads(urllib.request.urlopen('https://www.howsmyssl.com/a/check').read())['tls_version'])"

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/lib/python3.4/json/__init__.py", line 312, in loads
    s.__class__.__name__))
TypeError: the JSON object must be str, not 'bytes'

   Fix:

$ python3 -c "import urllib.request,json; print(json.loads(urllib.request.urlopen('https://www.howsmyssl.com/a/check').read().decode('ascii'))['tls_version'])"

Oleg.
-- 
     Oleg Broytman            http://phdru.name/            phd at phdru.name
           Programmers don't die, they just GOSUB without RETURN.


From donald at python.org  Tue Jan 10 10:01:22 2017
From: donald at python.org (Donald Stufft)
Date: Tue, 10 Jan 2017 10:01:22 -0500
Subject: Announcement: TLSv1.2 will become mandatory in the future for
 Python.org Sites
In-Reply-To: <20170110145945.GA2925@phdru.name>
References: <1B1B29CD-AA4E-47C0-89A8-2748D5A14FC3@python.org>
 <20170110145945.GA2925@phdru.name>
Message-ID: <04A82852-13DF-422E-8A29-03C8E8261DCB@python.org>


> On Jan 10, 2017, at 9:59 AM, Oleg Broytman <phd at phdru.name> wrote:
> 
> On Tue, Jan 10, 2017 at 08:27:21AM -0500, Donald Stufft <donald at python.org> wrote:
>>    python3 -c "import urllib.request,json; print(json.loads(urllib.request.urlopen('https://www.howsmyssl.com/a/check').read())['tls_version'])"
> 
> Traceback (most recent call last):
>  File "<string>", line 1, in <module>
>  File "/usr/lib/python3.4/json/__init__.py", line 312, in loads
>    s.__class__.__name__))
> TypeError: the JSON object must be str, not ?bytes'
> 


Huh, just tested, my original snippet works on Python 3.6 but fails on Python 3.5. 



From p.f.moore at gmail.com  Tue Jan 10 10:47:00 2017
From: p.f.moore at gmail.com (Paul Moore)
Date: Tue, 10 Jan 2017 07:47:00 -0800 (PST)
Subject: The hardest problem in computer science...
In-Reply-To: <mailman.316.1483816473.2395.python-list@python.org>
References: <586f95ac$0$1589$c3e8da3$5496439d@news.astraweb.com>
 <587099fa$0$1610$c3e8da3$5496439d@news.astraweb.com>
 <58713BF8.7080803@stoneleaf.us>
 <mailman.316.1483816473.2395.python-list@python.org>
Message-ID: <a10d4b71-78bf-4e04-8d83-427b4b79aa20@googlegroups.com>

On Saturday, 7 January 2017 19:14:43 UTC, Ethan Furman  wrote:
> Ya know, that looks an /awful/ lot like a collection!  Maybe even an Enum?  ;)
> 
> -- 8< -------------------------------------------------------
> from aenum import Enum   # note the 'a' before the 'enum'  :)
> 
> class Theme(Enum, init='v vr llc'):
>      DEFAULT = "?  ", "?? ", "?? "
>      BOLD = "?  ", "?? ", "?? "
>      ASCII = "|  ", "|- ", "+- "
> 
> def draw_tree(tree, theme=Theme.DEFAULT):
>      print(theme.v)
>      print(theme.vr)
>      print(theme.v)
>      print(theme.llc)
> 
> draw_tree(None)

I noted the "a" before enum :-)

Is the implication that this form (a sort of combined namedtuple/enum) *isn't* possible with the stdlib enum? But rather that it's specific to your aenum module? I don't see any documentation for the "init" parameter in either version, so I'm a little puzzled.

The capability seems neat, although (as is probably obvious) the way you declare it seems a little confusing to me.

Paul


From p.f.moore at gmail.com  Tue Jan 10 11:06:35 2017
From: p.f.moore at gmail.com (Paul Moore)
Date: Tue, 10 Jan 2017 08:06:35 -0800 (PST)
Subject: The hardest problem in computer science...
In-Reply-To: <a10d4b71-78bf-4e04-8d83-427b4b79aa20@googlegroups.com>
References: <586f95ac$0$1589$c3e8da3$5496439d@news.astraweb.com>
 <587099fa$0$1610$c3e8da3$5496439d@news.astraweb.com>
 <58713BF8.7080803@stoneleaf.us>
 <mailman.316.1483816473.2395.python-list@python.org>
 <a10d4b71-78bf-4e04-8d83-427b4b79aa20@googlegroups.com>
Message-ID: <6cde77f0-255e-414f-9d53-8e016a884074@googlegroups.com>

On Tuesday, 10 January 2017 15:47:20 UTC, Paul  Moore  wrote:
> On Saturday, 7 January 2017 19:14:43 UTC, Ethan Furman  wrote:
> > Ya know, that looks an /awful/ lot like a collection!  Maybe even an Enum?  ;)
> > 
> > -- 8< -------------------------------------------------------
> > from aenum import Enum   # note the 'a' before the 'enum'  :)
> > 
> > class Theme(Enum, init='v vr llc'):
> >      DEFAULT = "?  ", "?? ", "?? "
> >      BOLD = "?  ", "?? ", "?? "
> >      ASCII = "|  ", "|- ", "+- "
> > 
> > def draw_tree(tree, theme=Theme.DEFAULT):
> >      print(theme.v)
> >      print(theme.vr)
> >      print(theme.v)
> >      print(theme.llc)
> > 
> > draw_tree(None)
> 
> I noted the "a" before enum :-)
> 
> Is the implication that this form (a sort of combined namedtuple/enum) *isn't* possible with the stdlib enum? But rather that it's specific to your aenum module? I don't see any documentation for the "init" parameter in either version, so I'm a little puzzled.
> 
> The capability seems neat, although (as is probably obvious) the way you declare it seems a little confusing to me.
> 
> Paul

After a bit more digging I found https://docs.python.org/3.6/library/enum.html#planet which looks like a stdlib-supported way of doing the same sort of thing. I assume init is an aenum convenience argument to do the same?

Anyway, it's a neat feature - I'd not really looked beyond the surface of the new enum module, looks like I missed some good stuff :-)

Paul


From irmen.NOSPAM at xs4all.nl  Tue Jan 10 12:24:10 2017
From: irmen.NOSPAM at xs4all.nl (Irmen de Jong)
Date: Tue, 10 Jan 2017 18:24:10 +0100
Subject: Announcement: TLSv1.2 will become mandatory in the future for
 Python.org Sites
In-Reply-To: <mailman.453.1484065329.2395.python-list@python.org>
References: <1B1B29CD-AA4E-47C0-89A8-2748D5A14FC3@python.org>
 <20170110145945.GA2925@phdru.name>
 <04A82852-13DF-422E-8A29-03C8E8261DCB@python.org>
 <mailman.453.1484065329.2395.python-list@python.org>
Message-ID: <587518b7$0$21416$e4fe514c@news.xs4all.nl>

On 10-1-2017 16:01, Donald Stufft wrote:
>> TypeError: the JSON object must be str, not ?bytes'
> Huh, just tested, my original snippet works on Python 3.6 but fails on Python 3.5. 


My guess is that is due to an improvement in 3.6 mentioned here:
https://docs.python.org/3/whatsnew/3.6.html#json

Irmen




From jladasky at itu.edu  Tue Jan 10 15:10:19 2017
From: jladasky at itu.edu (jladasky at itu.edu)
Date: Tue, 10 Jan 2017 12:10:19 -0800 (PST)
Subject: Help with this code
In-Reply-To: <mailman.408.1483994998.2395.python-list@python.org>
References: <84a38553-c6bb-4c6d-9247-eb22a69fe897@googlegroups.com>
 <PeQcA.459692$Yj7.154339@fx15.am4>
 <DB5PR07MB0806C2B0B456515C91BD31DAF0640@DB5PR07MB0806.eurprd07.prod.outlook.com>
 <mailman.408.1483994998.2395.python-list@python.org>
Message-ID: <fa883d3b-0a84-48ae-84c1-cc2cf097aebc@googlegroups.com>

On Monday, January 9, 2017 at 12:50:11 PM UTC-8, Joaquin Alzola wrote:
> >> elements. For example, if we have a list_a=["a","b","c","d"] and
> >> list_b=["a","b"] I want to obtain a new list_c containing elements that
> >> match between these lists (a and b here),
> 
> >Perhaps this might work:
> 
> >>>> list(set(list_a).intersection(set(list_b)))
> >['a', 'b']
> 
> >>> list_a={"a","b","c","d"}
> >>> list_b={"a","b"}
> > sorted(list_a & list_b)
> ['a', 'b']

You might want to use some other names for the objects you defined: "list_a" and "list_b" are not lists, they are sets.  Of course it doesn't matter if it's two throw-away lines typed into the interpreter, but in code that you share with someone else (especially a beginner like the OP), it could be confusing.


From zxpatric at gmail.com  Tue Jan 10 17:57:51 2017
From: zxpatric at gmail.com (Patrick Zhou)
Date: Tue, 10 Jan 2017 14:57:51 -0800 (PST)
Subject: Work between multiple processes
In-Reply-To: <2985338719@f38.n261.z1.binkp.net>
References: <2510477911@f38.n261.z1.binkp.net>
 <2985338719@f38.n261.z1.binkp.net>
Message-ID: <e839a44c-7a3f-4548-ad3a-2d756ef11649@googlegroups.com>

Hi Irmen,

I have successfully got it to work with both side as python but so far having trouble with pyrolite.jar which is downloaded from https://mvnrepository.com/artifact/net.razorvine/pyrolite/4.4


Having simple codes as:

    public static void main(String[] args) {
//        System.out.println("Hello world");

        try {
            String uri = "PYRO:obj_12a65b09f95f4ee9bec5958f819ced45 at localhost:64404";
            PyroURI pyURI = new PyroURI(uri);
            PyroProxy pyroP = new PyroProxy(pyURI);

            Object result = pyroP.call("getDst");
            String message = (String) result;
            System.out.println("result message=" + message);
            pyroP.close();
        }
        catch (IOException e1) {
            System.out.println(e1.getMessage());
        }
        catch (PickleException e2)
        {
            System.out.println(e2.getMessage());
        }
        catch (PyroException e3)
        {
            System.out.println(e3.getMessage());
        }
    }

which "getDst" works on Java but hangs on handshake() in the call function. 

Any thought? Thanks. -P


From steve+comp.lang.python at pearwood.info  Tue Jan 10 20:10:13 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 11 Jan 2017 12:10:13 +1100
Subject: Temporary variables in list comprehensions
References: <58730938$0$1597$c3e8da3$5496439d@news.astraweb.com>
 <718d3926-e673-3d7b-e55c-8df5db719957@rece.vub.ac.be>
 <mailman.381.1483967642.2395.python-list@python.org>
Message-ID: <587585f7$0$1621$c3e8da3$5496439d@news.astraweb.com>

On Tuesday 10 January 2017 00:12, Antoon Pardon wrote:

> Op 09-01-17 om 04:53 schreef Steven D'Aprano:
>> Suppose you have an expensive calculation that gets used two or more times
>> in a loop. The obvious way to avoid calculating it twice in an ordinary loop
>> is with a temporary variable:
[...]
>> I can't decide whether that's an awesome trick or a horrible hack...
> 
> Maybe this in an occasion to use your recipe.
> 
> http://code.activestate.com/recipes/580625-collection-pipeline-in-python/
> 
> result = data | Map(expensive_calculation) | Map(lambda tmp: (tmp, tmp + 1))
> | List
> 


Indeed :-)



-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From gerald.britton at gmail.com  Tue Jan 10 20:26:38 2017
From: gerald.britton at gmail.com (Gerald Britton)
Date: Tue, 10 Jan 2017 20:26:38 -0500
Subject: Question about abstract base classes and abstract properties --
 Python 2.7
In-Reply-To: <CAPxRSnaBys-thsCB56KPZ2EoPj9gu5O9Ostvdhqs9GDJH2DmbQ@mail.gmail.com>
References: <CAPxRSnaBys-thsCB56KPZ2EoPj9gu5O9Ostvdhqs9GDJH2DmbQ@mail.gmail.com>
Message-ID: <CAPxRSnb5Ydu23uTWUTpU9=_4bLqHbF=s=SJuD1F2HGg2o2NrQQ@mail.gmail.com>

I was rereading the 2.7 docs  about abstract base classes the other day.  I
found this line in the usage section of the abc.abstractproperty function:

"This defines a read-only property; you can also define a read-write
abstract property using the ?long? form of property declaration:"

along with an example.  so I copied the example and put in a little
surrounding code:


from abc import ABCMeta, abstractproperty

class C(object):
    __metaclass__ = ABCMeta
    def getx(self): pass
    def setx(self, value): pass
    x = abstractproperty(getx, setx)

class D(C):
    @property
    def x(self):self._x

d = D()
print(d)

When I ran this, I expected an exception, since I defined a read/write
abstract property but only implemented the read operation.  However, the
example runs fine. That is the class D can be instantiated without error.
Of course I cannot set the property since I didn't implement that part.

Now, If I don't implement the property at all, I can't instantiate the
class.  I get:

"TypeError: Can't instantiate abstract class D with abstract methods x"

which is what I would expect.  What I don't understand is why I don't get a
similar error when I implement the read operation for the property but not
the write operation.

If this actually doesn't work (catching the non-implementation at
instantiation time), then would it be appropriate to amend the
documentation?  To me at least the doc implies that it *will* raise on the
missing write property implementation (otherwise, what's the point of the
example?)

Or, am I just not grokking it properly?


From ethan at stoneleaf.us  Tue Jan 10 21:07:34 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 10 Jan 2017 18:07:34 -0800
Subject: The hardest problem in computer science...
In-Reply-To: <6cde77f0-255e-414f-9d53-8e016a884074@googlegroups.com>
References: <586f95ac$0$1589$c3e8da3$5496439d@news.astraweb.com>
 <587099fa$0$1610$c3e8da3$5496439d@news.astraweb.com>
 <58713BF8.7080803@stoneleaf.us>
 <mailman.316.1483816473.2395.python-list@python.org>
 <a10d4b71-78bf-4e04-8d83-427b4b79aa20@googlegroups.com>
 <6cde77f0-255e-414f-9d53-8e016a884074@googlegroups.com>
Message-ID: <58759366.5050207@stoneleaf.us>

On 01/10/2017 08:06 AM, Paul Moore wrote:
> On Tuesday, 10 January 2017 15:47:20 UTC, Paul  Moore  wrote:
>> On Saturday, 7 January 2017 19:14:43 UTC, Ethan Furman  wrote:

>>> Ya know, that looks an /awful/ lot like a collection!  Maybe even an Enum?  ;)
>>>
>>> -- 8< -------------------------------------------------------
>>> from aenum import Enum   # note the 'a' before the 'enum'  :)
>>>
>>> class Theme(Enum, init='v vr llc'):
>>>       DEFAULT = "?  ", "?? ", "?? "
>>>       BOLD = "?  ", "?? ", "?? "
>>>       ASCII = "|  ", "|- ", "+- "
>>>
>>> def draw_tree(tree, theme=Theme.DEFAULT):
>>>       print(theme.v)
>>>       print(theme.vr)
>>>       print(theme.v)
>>>       print(theme.llc)
>>>
>>> draw_tree(None)
>>
>> I noted the "a" before enum :-)
>>
>> Is the implication that this form (a sort of combined namedtuple/enum)
>>  *isn't* possible with the stdlib enum? But rather that it's specific
>>  to your aenum module?

It's possible with the stdlib version, and a built-in convenience with aenum.

>>  I don't see any documentation for the "init"
>>  parameter in either version, so I'm a little puzzled.

It's in the docs for aenum, which you will get with the source download.  I need to figure out how to get them included in the wheels.  :(

>> The capability seems neat, although (as is probably obvious) the way you
>>  declare it seems a little confusing to me.

Yes, it is possible to pass keyword arguments in a class header, although (as far as I know) very few make use of this.

> Anyway, it's a neat feature - I'd not really looked beyond the surface of
>  the new enum module, looks like I missed some good stuff :-)

Lot's of good stuff in the stdlib, but who has time to learn it all?  :(

--
~Ethan~


From steve+comp.lang.python at pearwood.info  Tue Jan 10 21:16:43 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 11 Jan 2017 13:16:43 +1100
Subject: Question about abstract base classes and abstract properties --
 Python 2.7
References: <CAPxRSnaBys-thsCB56KPZ2EoPj9gu5O9Ostvdhqs9GDJH2DmbQ@mail.gmail.com>
 <CAPxRSnb5Ydu23uTWUTpU9=_4bLqHbF=s=SJuD1F2HGg2o2NrQQ@mail.gmail.com>
 <mailman.454.1484098007.2395.python-list@python.org>
Message-ID: <5875958c$0$1595$c3e8da3$5496439d@news.astraweb.com>

On Wednesday 11 January 2017 12:26, Gerald Britton wrote:

> I was rereading the 2.7 docs  about abstract base classes the other day.  I
> found this line in the usage section of the abc.abstractproperty function:
> 
> "This defines a read-only property; you can also define a read-write
> abstract property using the ?long? form of property declaration:"
> 
> along with an example.  so I copied the example and put in a little
> surrounding code:
> 
> 
> from abc import ABCMeta, abstractproperty
> 
> class C(object):
>     __metaclass__ = ABCMeta
>     def getx(self): pass
>     def setx(self, value): pass
>     x = abstractproperty(getx, setx)
>
> class D(C):
>     @property
>     def x(self):self._x
> 
> d = D()
> print(d)
> 
> When I ran this, I expected an exception, since I defined a read/write
> abstract property but only implemented the read operation.

I expected the same thing.


[...]
> If this actually doesn't work (catching the non-implementation at
> instantiation time), then would it be appropriate to amend the
> documentation?  To me at least the doc implies that it *will* raise on the
> missing write property implementation (otherwise, what's the point of the
> example?)

Personally, I consider this a design bug: as designed, abstractproperty is 
broken. But I couldn't call it a functional bug: it looks like it is working as 
documented, as useless as that it.

Note that in Python 3.3 and better, abstractproperty is deprecated: the ABC 
metaclass is smart enough to work with the regular property decorator:

https://docs.python.org/3.6/library/abc.html#abc.abstractproperty



> Or, am I just not grokking it properly?

No, I agree with you. I think that a bug request to improve the documentation 
is appropriate.



-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From steve+comp.lang.python at pearwood.info  Tue Jan 10 21:18:49 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 11 Jan 2017 13:18:49 +1100
Subject: Using namedtuples field names for column indices in a list of
 lists
References: <587479C0.7050401@stoneleaf.us>
 <009501d26b11$281a3d30$27b23dae@sambora>
 <mailman.441.1484032461.2395.python-list@python.org>
Message-ID: <58759609$0$1595$c3e8da3$5496439d@news.astraweb.com>

On Tuesday 10 January 2017 18:14, Deborah Swanson wrote:

> I'm guessing that you (and those who
> see things like you do) might not be used to working with quick learners
> who make mistakes at first but catch up with them real fast, or you're
> very judgemental about people who make mistakes, period. I certainly
> don't care if you want to judge me, you're entitled to your opinion.

Be fair. We're not mind-readers, and we're trying to help you, not attack you.

It is true that we're often extremely pedantic. Sometimes annoyingly so, but on 
the other hand precision is important, especially in technical fields. There's 
a *huge* difference between a MTA and a MUA, even though they differ only by 
one letter and both are related to email.

One of the techs I work with has the same habit of correcting me, and when I'm 
invariably forced to agree that he is technical correct, he replies "technical 
correctness is the best kind of correctness". Annoying as it is to be on the 
receiving end, he is right: at least half the time I learn something from his 
pedantry. (The other half of the time, its a difference that makes no 
difference.)


What are we supposed to do when somebody asks a question based on an obvious 
mistake? Assume that they're a quick learner who has probably already worked 
out their mistake and doesn't need an answer? That would certainly make our 
life easier: we can just ignore everybody's questions.

Sometimes people make errors of terminology that doesn't affect the semantics 
of what they're asking:

    "I have an array [1, 2, 3, 4] and I want to ..."

It's very likely that they have a list and they're merely using a term they're 
familiar with from another language, rather than the array module.

But what are we supposed to make of mistakes that *do* affect the semantics of 
the question:

    "I have a dict of ints {1, 2, 3, 4} and want to sort the values by 
    key so that I get [4, 2, 3, 1], how do I do that?"

How can we answer that without correcting their misuse of terminology and 
asking for clarification of what data structure they *actually* have?

We get questions like this very frequently. How would you answer it?


Or:

    "I have a list l = namedtuple('l', 'field1 field2') and can't 
    extract fields by index, l[0] doesn't work..."

Of course it doesn't work. How would you respond to that if you were in our 
place?

- ignore the question because the poster is ever so smart and will have
  worked it out by now?

- point out that l is not a list, or even a tuple, and of course l[0] 
  doesn't work because l is actually a class?

Its easy to criticise us for answering the questions you ask instead of the 
questions you intended, but we're not mind-readers. We don't know what you're 
thinking, we only know what you communicate to us. Telling us off for answering 
your questions is hardly likely to encourage us to answer them in the future.




-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From bc at freeuk.com  Wed Jan 11 08:27:38 2017
From: bc at freeuk.com (BartC)
Date: Wed, 11 Jan 2017 13:27:38 +0000
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <58759609$0$1595$c3e8da3$5496439d@news.astraweb.com>
References: <587479C0.7050401@stoneleaf.us>
 <009501d26b11$281a3d30$27b23dae@sambora>
 <mailman.441.1484032461.2395.python-list@python.org>
 <58759609$0$1595$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <o55bpd$br9$1@dont-email.me>

On 11/01/2017 02:18, Steven D'Aprano wrote:
> On Tuesday 10 January 2017 18:14, Deborah Swanson wrote:
>
>> I'm guessing that you (and those who
>> see things like you do) might not be used to working with quick learners
>> who make mistakes at first but catch up with them real fast, or you're
>> very judgemental about people who make mistakes, period. I certainly
>> don't care if you want to judge me, you're entitled to your opinion.
>
> Be fair. We're not mind-readers, and we're trying to help you, not attack you.
>
> It is true that we're often extremely pedantic. Sometimes annoyingly so, but on
> the other hand precision is important, especially in technical fields. There's
> a *huge* difference between a MTA and a MUA, even though they differ only by
> one letter and both are related to email.

There's a bigger difference between USB and USA!

-- 
Bartc




From pengyu.ut at gmail.com  Wed Jan 11 10:51:19 2017
From: pengyu.ut at gmail.com (Peng Yu)
Date: Wed, 11 Jan 2017 09:51:19 -0600
Subject: Is there an peekable similar to peekable but in additional allowing
 one to put some data to it?
Message-ID: <CABrM6wnBz2CseBkVHY6x5fE_VA0Z2i18Oo+iT0SqVV+uorkr8Q@mail.gmail.com>

Hi, peekable from more-itertools only allow peeking an iterator. But
sometimes, one may want to take a look at an element, manipulate it,
then put it back to the iterator. Is there a class in python that can
help do this?

https://pypi.python.org/pypi/more-itertools/

-- 
Regards,
Peng


From rustompmody at gmail.com  Wed Jan 11 11:50:33 2017
From: rustompmody at gmail.com (Rustom Mody)
Date: Wed, 11 Jan 2017 08:50:33 -0800 (PST)
Subject: reactiveX vs Async
Message-ID: <c7309382-f8ed-49a4-bd41-2fbdce422852@googlegroups.com>

There is the recent flurry around the new async additions to python

Also, addressing the same problem area, there is the slightly older reactiveX 
system that seems to have bindings for at least 15 mainstream languages? 
including python: http://reactivex.io/

Has someone been able to put these two in context? To relate one to the other?


From rustompmody at gmail.com  Wed Jan 11 11:53:40 2017
From: rustompmody at gmail.com (Rustom Mody)
Date: Wed, 11 Jan 2017 08:53:40 -0800 (PST)
Subject: reactiveX vs Async
In-Reply-To: <c7309382-f8ed-49a4-bd41-2fbdce422852@googlegroups.com>
References: <c7309382-f8ed-49a4-bd41-2fbdce422852@googlegroups.com>
Message-ID: <a42964f6-f224-4039-b893-e5d7d227656a@googlegroups.com>

On Wednesday, January 11, 2017 at 10:21:02 PM UTC+5:30, Rustom Mody wrote:
> There is the recent flurry around the new async additions to python

I meant to add: ?? which I dont pretend to understand??


From ian.g.kelly at gmail.com  Wed Jan 11 12:07:35 2017
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 11 Jan 2017 10:07:35 -0700
Subject: Is there an peekable similar to peekable but in additional
 allowing one to put some data to it?
In-Reply-To: <CABrM6wnBz2CseBkVHY6x5fE_VA0Z2i18Oo+iT0SqVV+uorkr8Q@mail.gmail.com>
References: <CABrM6wnBz2CseBkVHY6x5fE_VA0Z2i18Oo+iT0SqVV+uorkr8Q@mail.gmail.com>
Message-ID: <CALwzidnPRRF1DD4X1kgTjOc0Q2xm24v0xjm9C2_phMVOgnofuQ@mail.gmail.com>

On Wed, Jan 11, 2017 at 8:51 AM, Peng Yu <pengyu.ut at gmail.com> wrote:
> Hi, peekable from more-itertools only allow peeking an iterator. But
> sometimes, one may want to take a look at an element, manipulate it,
> then put it back to the iterator. Is there a class in python that can
> help do this?

Not that I'm aware of, but maybe this recipe will help.


from collections import deque

class PushIterator:

    def __init__(self, iterable, push=()):
        self._iter = iter(iterable)
        self._pushed = deque(push)
        self._stopped = False

    def push(self, item):
        if self._stopped:
            raise RuntimeError('Cannot push onto exhausted iterator')
        self._pushed.append(item)

    def __iter__(self):
        return self

    def __next__(self):
        if self._pushed:
            return self._pushed.pop()
        try:
            return next(self._iter)
        except StopIteration:
            self._stopped = True
            raise


From ian.g.kelly at gmail.com  Wed Jan 11 12:15:39 2017
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 11 Jan 2017 10:15:39 -0700
Subject: Is there an peekable similar to peekable but in additional
 allowing one to put some data to it?
In-Reply-To: <CALwzidnPRRF1DD4X1kgTjOc0Q2xm24v0xjm9C2_phMVOgnofuQ@mail.gmail.com>
References: <CABrM6wnBz2CseBkVHY6x5fE_VA0Z2i18Oo+iT0SqVV+uorkr8Q@mail.gmail.com>
 <CALwzidnPRRF1DD4X1kgTjOc0Q2xm24v0xjm9C2_phMVOgnofuQ@mail.gmail.com>
Message-ID: <CALwzid=Thyyf+TDdtv-aYY-=3JPTViYut+CfAHLFjC1H8XOWzA@mail.gmail.com>

On Wed, Jan 11, 2017 at 10:07 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> On Wed, Jan 11, 2017 at 8:51 AM, Peng Yu <pengyu.ut at gmail.com> wrote:
>> Hi, peekable from more-itertools only allow peeking an iterator. But
>> sometimes, one may want to take a look at an element, manipulate it,
>> then put it back to the iterator. Is there a class in python that can
>> help do this?
>
> Not that I'm aware of, but maybe this recipe will help.
>
>
> from collections import deque
>
> class PushIterator:
>
>     def __init__(self, iterable, push=()):
>         self._iter = iter(iterable)
>         self._pushed = deque(push)
>         self._stopped = False
>
>     def push(self, item):
>         if self._stopped:
>             raise RuntimeError('Cannot push onto exhausted iterator')
>         self._pushed.append(item)
>
>     def __iter__(self):
>         return self
>
>     def __next__(self):
>         if self._pushed:
>             return self._pushed.pop()
>         try:
>             return next(self._iter)
>         except StopIteration:
>             self._stopped = True
>             raise


And in case it's not obvious, adding a peek method to this is pretty simple:


from collections import deque

class PushIterator:

    def __init__(self, iterable, push=()):
        self._iter = iter(iterable)
        self._pushed = deque(push)
        self._stopped = False

    def peek(self):
        item = next(self)
        self.push(item)
        return item

    def push(self, item):
        if self._stopped:
            raise RuntimeError('Cannot push onto exhausted iterator')
        self._pushed.append(item)

    def __iter__(self):
        return self

    def __next__(self):
        if self._pushed:
            return self._pushed.pop()
        try:
            return next(self._iter)
        except StopIteration:
            self._stopped = True
            raise


From falter_donald at bah.com  Wed Jan 11 12:31:42 2017
From: falter_donald at bah.com (Falter, Donald [USA])
Date: Wed, 11 Jan 2017 17:31:42 +0000
Subject: Cannot import GDAL
Message-ID: <93285AC0FA20BA47BE43FA54FCA5B321EDD9AE3B@ASHBDAG2M3.resource.ds.bah.com>

I am new to Python and I am trying to utilize GDAL.  I installed Python 3.6.  The version I get when I activate IDLE is: MSC v.1900 32 bit (Intel)] on win32.  In downloading the GDAL bindings the latest version I can find is release-1800-gdal-2-1-2-mapserver-7-0-2 so I installed the following: gdal-201-1800-core.msi and GDAL-2.1.2.win32-py3.4.msi.

I added C:\Program Files\GDAL to my path and added the system variables GDAL_DATA = C:\Program Files\GDAL\gdal-data and\
GDAL_DRIVER_PATH = C:\Program Files\GDAL\gdalplugins

When I open IDLE and type the following: from osgeo import gdal I get the following error

>>> from osgeo import gdal
Traceback (most recent call last):
  File "<pyshell#0>", line 1, in <module>
    from osgeo import gdal
ModuleNotFoundError: No module named 'osgeo'
>>>

I have been all over the internet looking for answer but have found none that work.  Some real help here would be appreciated.

Thanks,
Don



From irmen.NOSPAM at xs4all.nl  Wed Jan 11 15:07:34 2017
From: irmen.NOSPAM at xs4all.nl (Irmen de Jong)
Date: Wed, 11 Jan 2017 21:07:34 +0100
Subject: Work between multiple processes
In-Reply-To: <e839a44c-7a3f-4548-ad3a-2d756ef11649@googlegroups.com>
References: <2510477911@f38.n261.z1.binkp.net>
 <2985338719@f38.n261.z1.binkp.net>
 <e839a44c-7a3f-4548-ad3a-2d756ef11649@googlegroups.com>
Message-ID: <58769083$0$21443$e4fe514c@news.xs4all.nl>

On 10-1-2017 23:57, Patrick Zhou wrote:
> Hi Irmen,
> 
> I have successfully got it to work with both side as python but so far having trouble with pyrolite.jar which is downloaded from https://mvnrepository.com/artifact/net.razorvine/pyrolite/4.4
> 
> 

[...]

> 
> which "getDst" works on Java but hangs on handshake() in the call function. 
> 
> Any thought? Thanks. -P
> 

Yeah, don't use the oldest version of the library available, use the newest ;-)
https://mvnrepository.com/artifact/net.razorvine/pyrolite/4.15


Irmen



From irmen.NOSPAM at xs4all.nl  Wed Jan 11 16:35:50 2017
From: irmen.NOSPAM at xs4all.nl (Irmen de Jong)
Date: Wed, 11 Jan 2017 22:35:50 +0100
Subject: Cannot import GDAL
In-Reply-To: <mailman.460.1484156080.2395.python-list@python.org>
References: <93285AC0FA20BA47BE43FA54FCA5B321EDD9AE3B@ASHBDAG2M3.resource.ds.bah.com>
 <mailman.460.1484156080.2395.python-list@python.org>
Message-ID: <5876a533$0$21466$e4fe514c@news.xs4all.nl>

On 11-1-2017 18:31, Falter, Donald [USA] wrote:
> I am new to Python and I am trying to utilize GDAL.  I installed Python 3.6.
> I installed the following: gdal-201-1800-core.msi and GDAL-2.1.2.win32-py3.4.msi.

Those don't match. You'll have to use a MSI built for py3.6, one thinks.

Either install and use Python 3.4 with this (rather than 3.6) or find the approprite
installer for python 3.6. It seems that you can get one here:
http://www.lfd.uci.edu/~gohlke/pythonlibs/#gdal


Irmen



From fabien.maussion at gmail.com  Wed Jan 11 16:59:27 2017
From: fabien.maussion at gmail.com (Fabien)
Date: Wed, 11 Jan 2017 22:59:27 +0100
Subject: Cannot import GDAL
References: <93285AC0FA20BA47BE43FA54FCA5B321EDD9AE3B@ASHBDAG2M3.resource.ds.bah.com>
 <mailman.460.1484156080.2395.python-list@python.org>
Message-ID: <o569ru$17qr$1@gioia.aioe.org>

On 01/11/2017 06:31 PM, Falter, Donald [USA] wrote:
> I am new to Python and I am trying to utilize GDAL

GDAL is notoriously difficult to install :-(

I would strongly recommend to use conda 
(http://conda.pydata.org/miniconda.html) for managing your packages and 
environments, and then use the conda-forge channel 
(https://conda-forge.github.io/) to install gdal:

conda install -c conda-forge gdal

Good luck!

Fabien


From fabien.maussion at gmail.com  Wed Jan 11 17:06:00 2017
From: fabien.maussion at gmail.com (Fabien)
Date: Wed, 11 Jan 2017 23:06:00 +0100
Subject: Cannot import GDAL
References: <93285AC0FA20BA47BE43FA54FCA5B321EDD9AE3B@ASHBDAG2M3.resource.ds.bah.com>
 <mailman.460.1484156080.2395.python-list@python.org>
 <o569ru$17qr$1@gioia.aioe.org>
Message-ID: <o56a87$18bq$1@gioia.aioe.org>

On 01/11/2017 10:59 PM, Fabien wrote:
> I would strongly recommend to use conda
> (http://conda.pydata.org/miniconda.html) for managing your packages and
> environments, and then use the conda-forge channel
> (https://conda-forge.github.io/) to install gdal:
>
> conda install -c conda-forge gdal


I forgot to mention that since py3.6 is quite recent, most packages 
still don't have binaries ready for it. Staying with py3.5 is a better 
idea for now.




From python at deborahswanson.net  Wed Jan 11 17:57:24 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Wed, 11 Jan 2017 14:57:24 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <58759609$0$1595$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <001f01d26c5e$13762080$27b23dae@sambora>

Steven D'Aprano wrote, on January 10, 2017 6:19 PM
> 
> On Tuesday 10 January 2017 18:14, Deborah Swanson wrote:
> 
> > I'm guessing that you (and those who see things like you do) might 
> > not be used to working with quick learners who make mistakes at 
> > first but catch up with them real fast, or you're very judgemental 
> > about people who make mistakes, period. I certainly don't care if 
> > you want to judge me, you're entitled to your opinion.
> 
> Be fair. We're not mind-readers, and we're trying to help you, not 
> attack you.

You aren't, and I've never seen you as attacking me, but there's a few
others here who have attacked me, and they weren't trying to help me
either. But it's only a very few people who've harrassed me, and the
person I was writing to above wasn't one of them. 

> It is true that we're often extremely pedantic. Sometimes annoyingly
> so, but on the other hand precision is important, especially in 
> technical fields. > There's a *huge* difference between a MTA and a 
> MUA, even though they differ only by one letter and both are related 
> to email.
>
> One of the techs I work with has the same habit of correcting me, and 
> when I'm invariably forced to agree that he is technical correct, he 
> replies "technical correctness is the best kind of correctness". 
> Annoying as it is to be on the receiving end, he is right: at least 
> half the time I learn something from his pedantry. (The other half of 
> the time, its a difference that makes no difference.)

I'm sorry you have to work with someone like that, he sounds perfectly
awful. (But that doesn't give you license to do the same. You're better
than that.)

> What are we supposed to do when somebody asks a question based on an
> obvious mistake? Assume that they're a quick learner who has probably 
> already worked out their mistake and doesn't need an answer? That 
> would certainly make our life easier: we can just ignore everybody's 
> questions.

No, of course not. My advice to people who want to help is to not assume
that you know what the question asker does and doesn't know, and just
answer the questions without obsessing about what they know. If that's
impossible because they have something so wrong that you don't know what
they're asking, that would be a good time to point it out and give them
a chance to correct it. 

> Sometimes people make errors of terminology that doesn't affect the 
> semantics of what they're asking:
> 
>     "I have an array [1, 2, 3, 4] and I want to ..."
> 
> It's very likely that they have a list and they're merely using a term

> they're familiar with from another language, rather than the array 
> module.
> 
> But what are we supposed to make of mistakes that *do* affect the 
> semantics of the question:
> 
>     "I have a dict of ints {1, 2, 3, 4} and want to sort the values by

>     key so that I get [4, 2, 3, 1], how do I do that?"
> 
> How can we answer that without correcting their misuse of terminology
> and asking for clarification of what data structure they *actually* 
> have?
>
> We get questions like this very frequently. How would you answer it?

Well, I'd tell them how to reverse sort a dictionary, and point out that
what they've given isn't a dictionary because it doesn't have any keys,
and on this occasion I'd just give them an example of what a dictionary
looks like (as part of showing them how to reverse sort it) with its
keys, including the curly braces, and see what they come back with. They
pretty clearly mean a dictionary and not a list, since they said "dict",
used curly braces, and said they want to sort the values by key" in the
first clause of their sentence. So they're just a little confused and
maybe absent-mindedly slipping back into the more familiar list notation
and concepts, or they don't exactly know what a dictionary is. I
wouldn't belabor the point at this time, unless they keep coming back
with the same issues. That would be the time to belabor it, in my
opinion.  When some people are learning it's hard to keep all the new
things firmly in mind and not confuse them with more familiar things
they already know. But if they get it all straight in reasonably good
time, that should be ok. 

> Or:
> 
>     "I have a list l = namedtuple('l', 'field1 field2') and can't 
>     extract fields by index, l[0] doesn't work..."
> 
> Of course it doesn't work. How would you respond to that if you were
> in our place?
> 
> - ignore the question because the poster is ever so smart and will
have
>   worked it out by now?
> 
> - point out that l is not a list, or even a tuple, and of course l[0] 
>   doesn't work because l is actually a class?

I'd go with some variant of option 2, depending on how well I knew the
person asking. If the asker had just dropped in out of the blue and I
knew nothing about them I'd say something like "You can't because 'l'
isn't a list." Then I'd try to gauge how useful it would be to them to
know exactly what 'l' is, but most likely I would be asking them one of
several questions next (depending on the context), because it's not
clear what they're trying to do. You can't proceed if you don't have
enough information to work with. (Well, you can, but it frequently
doesn't work out too well.)
 
> Its easy to criticise us for answering the questions you ask instead
> of the questions you intended, but we're not mind-readers. We don't 
> know what you're thinking, we only know what you communicate to us. 
> Telling us off for answering your questions is hardly likely to 
> encourage us to answer them in the future.
> --
> Steven
> "Ever since I learned about confirmation bias, I've been seeing it 
> everywhere." - Jon Ronson

I imagine that people answer questions because they're interested in the
question, or they want to help. But really, it's up to them whether they
want to answer it or not.



From jcasale at activenetwerx.com  Wed Jan 11 20:11:32 2017
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Thu, 12 Jan 2017 01:11:32 +0000
Subject: reactiveX vs Async
In-Reply-To: <a42964f6-f224-4039-b893-e5d7d227656a@googlegroups.com>
References: <c7309382-f8ed-49a4-bd41-2fbdce422852@googlegroups.com>
 <a42964f6-f224-4039-b893-e5d7d227656a@googlegroups.com>
Message-ID: <4062a277404f4823bf0baea1ae76dd8f@activenetwerx.com>

>> There is the recent flurry around the new async additions to python
>
> I meant to add: ?? which I dont pretend to understand??

Try these links on for size:

https://msdn.microsoft.com/en-us/library/hh242982(v=vs.103).aspx which links to
https://msdn.microsoft.com/en-us/library/hh242983(v=vs.103).aspx near the end.

That summarizes the conceptual difference pretty well imho. It's also summarized on
the .NET versions GitHub page: https://github.com/Reactive-Extensions/Rx.NET#a-brief-intro

I think you can summarize RX as a framework whereas async/await can be used without
significant buy-in (Overlook the "async top down or none at all" best practice sound bite).
That is, you can artificially convert a synchronous method into a threaded operation and
have it executely asynchronously while you do something else and wait on it for completion
at somne other time.

However, I have only used the .NET implementations.

jlc

From jcasale at activenetwerx.com  Wed Jan 11 20:15:30 2017
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Thu, 12 Jan 2017 01:15:30 +0000
Subject: reactiveX vs Async
In-Reply-To: <4062a277404f4823bf0baea1ae76dd8f@activenetwerx.com>
References: <c7309382-f8ed-49a4-bd41-2fbdce422852@googlegroups.com>
 <a42964f6-f224-4039-b893-e5d7d227656a@googlegroups.com>
 <4062a277404f4823bf0baea1ae76dd8f@activenetwerx.com>
Message-ID: <eb3ce818c34c444c9d73094215154d83@activenetwerx.com>

> Try these links on for size:
>
> https://msdn.microsoft.com/en-us/library/hh242982(v=vs.103).aspx which links to
> https://msdn.microsoft.com/en-us/library/hh242983(v=vs.103).aspx near the end.

These two SO threads have a variation of pretty good explanations:

http://stackoverflow.com/questions/2550763/good-example-of-reactive-extensions-use
http://stackoverflow.com/questions/1596158/good-introduction-to-the-net-reactive-framework



From rustompmody at gmail.com  Wed Jan 11 20:47:43 2017
From: rustompmody at gmail.com (Rustom Mody)
Date: Wed, 11 Jan 2017 17:47:43 -0800 (PST)
Subject: reactiveX vs Async
In-Reply-To: <mailman.463.1484184001.2395.python-list@python.org>
References: <c7309382-f8ed-49a4-bd41-2fbdce422852@googlegroups.com>
 <a42964f6-f224-4039-b893-e5d7d227656a@googlegroups.com>
 <4062a277404f4823bf0baea1ae76dd8f@activenetwerx.com>
 <mailman.463.1484184001.2395.python-list@python.org>
Message-ID: <abbdf6ab-a140-454c-9946-1e5794c57922@googlegroups.com>

On Thursday, January 12, 2017 at 6:50:09 AM UTC+5:30, Joseph L. Casale wrote:
> >> There is the recent flurry around the new async additions to python
> >
> > I meant to add: ?? which I dont pretend to understand??
> 
> Try these links on for size:
> 
> https://msdn.microsoft.com/en-us/library/hh242982(v=vs.103).aspx which links to
> https://msdn.microsoft.com/en-us/library/hh242983(v=vs.103).aspx near the end.
> 
> That summarizes the conceptual difference pretty well imho. It's also summarized on
> the .NET versions GitHub page: https://github.com/Reactive-Extensions/Rx.NET#a-brief-intro
> 
> I think you can summarize RX as a framework whereas async/await can be used without
> significant buy-in (Overlook the "async top down or none at all" best practice sound bite).
> That is, you can artificially convert a synchronous method into a threaded operation and
> have it executely asynchronously while you do something else and wait on it for completion
> at somne other time.
> 
> However, I have only used the .NET implementations.
> 
> jlc

Thanks Joseph
Trouble is there is stew of technologies/languages?
(meta)-stewed with more abstract concepts, eg push vs pull, Enumerable-Observable
duality, continuous vs discrete time
The last causing its own share of confusion with ?functional reactive programming? (FRP) meaning sometimes the one and sometimes the other:
http://lambda-the-ultimate.org/node/4982

As for 'Overlook the ?async/await can be used without significant buy-in? '
I believe Ive seen people with considerable experience/understanding of the area
take the opposite view, usually along the lines: ?Once you start going non-blocking,
you have to non-block all the way?


From rustompmody at gmail.com  Wed Jan 11 20:56:07 2017
From: rustompmody at gmail.com (Rustom Mody)
Date: Wed, 11 Jan 2017 17:56:07 -0800 (PST)
Subject: reactiveX vs Async
In-Reply-To: <mailman.463.1484184001.2395.python-list@python.org>
References: <c7309382-f8ed-49a4-bd41-2fbdce422852@googlegroups.com>
 <a42964f6-f224-4039-b893-e5d7d227656a@googlegroups.com>
 <4062a277404f4823bf0baea1ae76dd8f@activenetwerx.com>
 <mailman.463.1484184001.2395.python-list@python.org>
Message-ID: <93f66f14-c9ee-446e-9996-3971e96509f7@googlegroups.com>

On Thursday, January 12, 2017 at 6:50:09 AM UTC+5:30, Joseph L. Casale wrote:
> However, I have only used the .NET implementations.

One more question: Do you know if (and how much) of these things would work
in Linux/C# (ie mono)?


From tjreedy at udel.edu  Wed Jan 11 20:59:30 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Wed, 11 Jan 2017 20:59:30 -0500
Subject: Cannot import GDAL
In-Reply-To: <o56a87$18bq$1@gioia.aioe.org>
References: <93285AC0FA20BA47BE43FA54FCA5B321EDD9AE3B@ASHBDAG2M3.resource.ds.bah.com>
 <mailman.460.1484156080.2395.python-list@python.org>
 <o569ru$17qr$1@gioia.aioe.org> <o56a87$18bq$1@gioia.aioe.org>
Message-ID: <o56nu0$qpl$1@blaine.gmane.org>

On 1/11/2017 5:06 PM, Fabien wrote:
> On 01/11/2017 10:59 PM, Fabien wrote:
>> I would strongly recommend to use conda
>> (http://conda.pydata.org/miniconda.html) for managing your packages and
>> environments, and then use the conda-forge channel
>> (https://conda-forge.github.io/) to install gdal:
>>
>> conda install -c conda-forge gdal
>
>
> I forgot to mention that since py3.6 is quite recent, most packages
> still don't have binaries ready for it. Staying with py3.5 is a better
> idea for now.

http://www.lfd.uci.edu/~gohlke/pythonlibs/
has 32 and 64 bit 3.6 binaries for over 200 packages, including GDAL 2.1.2.


-- 
Terry Jan Reedy



From tjreedy at udel.edu  Wed Jan 11 21:06:15 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Wed, 11 Jan 2017 21:06:15 -0500
Subject: Cannot import GDAL
In-Reply-To: <93285AC0FA20BA47BE43FA54FCA5B321EDD9AE3B@ASHBDAG2M3.resource.ds.bah.com>
References: <93285AC0FA20BA47BE43FA54FCA5B321EDD9AE3B@ASHBDAG2M3.resource.ds.bah.com>
Message-ID: <o56oak$1jc$1@blaine.gmane.org>

On 1/11/2017 12:31 PM, Falter, Donald [USA] wrote:
> I am new to Python and I am trying to utilize GDAL.  I installed Python 3.6.  The version I get when I activate IDLE is: MSC v.1900 32 bit (Intel)] on win32.  In downloading the GDAL bindings the latest version I can find is release-1800-gdal-2-1-2-mapserver-7-0-2 so I installed the following: gdal-201-1800-core.msi and GDAL-2.1.2.win32-py3.4.msi.
>
> I added C:\Program Files\GDAL to my path and added the system variables GDAL_DATA = C:\Program Files\GDAL\gdal-data and\
> GDAL_DRIVER_PATH = C:\Program Files\GDAL\gdalplugins
>
> When I open IDLE and type the following: from osgeo import gdal I get the following error

IDLE does not normally cause imports to fail (though it often get 
blamed), but one can check by running, in this case, 3.6, from the 
Windows console (ie, Command Prompt) and trying the same import statement.

>>>> from osgeo import gdal
> Traceback (most recent call last):
>   File "<pyshell#0>", line 1, in <module>
>     from osgeo import gdal
> ModuleNotFoundError: No module named 'osgeo'

Does C:\Program Files\GDAL contain a package 'osgeo' containing a module 
'gdal'?

I am not sure if the version mismatch pointed out by others would cause 
that particular error.  If replacing the 3.4 package with a 3.6 package 
fixes your problem completely, please let us know.

-- 
Terry Jan Reedy



From jcasale at activenetwerx.com  Wed Jan 11 21:12:29 2017
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Thu, 12 Jan 2017 02:12:29 +0000
Subject: reactiveX vs Async
In-Reply-To: <abbdf6ab-a140-454c-9946-1e5794c57922@googlegroups.com>
References: <c7309382-f8ed-49a4-bd41-2fbdce422852@googlegroups.com>
 <a42964f6-f224-4039-b893-e5d7d227656a@googlegroups.com>
 <4062a277404f4823bf0baea1ae76dd8f@activenetwerx.com>
 <mailman.463.1484184001.2395.python-list@python.org>
 <abbdf6ab-a140-454c-9946-1e5794c57922@googlegroups.com>
Message-ID: <f3340d09a97b4845b3bb0bd8d5101094@activenetwerx.com>

> Thanks Joseph
> Trouble is there is stew of technologies/languages?
> (meta)-stewed with more abstract concepts, eg push vs pull, Enumerable-Observable
> duality, continuous vs discrete time
> The last causing its own share of confusion with ?functional reactive programming? (FRP) meaning sometimes the one and sometimes the other:
> http://lambda-the-ultimate.org/node/4982

Heh,
Yeah I don't claim to be an expert, I have only just started using the syntax
in my own projects whereas I almost always used the classical thread model
with sync primitives and message passing.

> As for 'Overlook the ?async/await can be used without significant buy-in? '
> I believe Ive seen people with considerable experience/understanding of the area
> take the opposite view, usually along the lines: ?Once you start going non-blocking,
> you have to non-block all the way?

Right, as I mentioned overlook the pedantic argument just for the concept.
While you *can* do as I mentioned rather easily, it's not a useful or scalable
approach. Their suggestion is correct in reality but I only mentioned the minimal
buy-in it to illustrate that existing code *could* adopt the pattern trivially
whereas Rx is not simply two keywords, it's an entire framework.

Ultimately they accomplish the same thing, that is asynchronous execution
but use two different patterns. I'll paraphrase another source: "Rx adds a
convenient way to add callbacks and manage execution." The async/await
pattern is closer to the metal, it's not dealing with a sequence of observable
objects, it is however manipulating execution of the explicit block of code where
its applied.

jlc

From jcasale at activenetwerx.com  Wed Jan 11 21:17:04 2017
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Thu, 12 Jan 2017 02:17:04 +0000
Subject: reactiveX vs Async
In-Reply-To: <93f66f14-c9ee-446e-9996-3971e96509f7@googlegroups.com>
References: <c7309382-f8ed-49a4-bd41-2fbdce422852@googlegroups.com>
 <a42964f6-f224-4039-b893-e5d7d227656a@googlegroups.com>
 <4062a277404f4823bf0baea1ae76dd8f@activenetwerx.com>
 <mailman.463.1484184001.2395.python-list@python.org>
 <93f66f14-c9ee-446e-9996-3971e96509f7@googlegroups.com>
Message-ID: <aef27b8cde514b1982b6df0cc9eeafd4@activenetwerx.com>

> One more question: Do you know if (and how much) of these things would work
> in Linux/C# (ie mono)?

Mono, I forgot what that is when .net core debuted:)

Looks like the .net Rx guys have a port, https://github.com/Reactive-Extensions/Rx.NET/issues/148

A package for .net core is up on nuget.

jlc


From rustompmody at gmail.com  Thu Jan 12 00:00:38 2017
From: rustompmody at gmail.com (Rustom Mody)
Date: Wed, 11 Jan 2017 21:00:38 -0800 (PST)
Subject: reactiveX vs Async
In-Reply-To: <mailman.467.1484187431.2395.python-list@python.org>
References: <c7309382-f8ed-49a4-bd41-2fbdce422852@googlegroups.com>
 <a42964f6-f224-4039-b893-e5d7d227656a@googlegroups.com>
 <4062a277404f4823bf0baea1ae76dd8f@activenetwerx.com>
 <mailman.463.1484184001.2395.python-list@python.org>
 <93f66f14-c9ee-446e-9996-3971e96509f7@googlegroups.com>
 <aef27b8cde514b1982b6df0cc9eeafd4@activenetwerx.com>
 <mailman.467.1484187431.2395.python-list@python.org>
Message-ID: <0a41fd4a-e51a-4f29-baf8-312cbb85f30f@googlegroups.com>

On Thursday, January 12, 2017 at 7:47:21 AM UTC+5:30, Joseph L. Casale wrote:
> > One more question: Do you know if (and how much) of these things would work
> > in Linux/C# (ie mono)?
> 
> Mono, I forgot what that is when .net core debuted:)

A brief elaboration on that please?? ? ?
> 
> Looks like the .net Rx guys have a port, https://github.com/Reactive-Extensions/Rx.NET/issues/148

All this makes little sense to me :-(
C# is a sweet language, in many small ways better than java
But Windows/.NET?? Hoo boy!
[Just an ol-nixer getting lost... No judgement really!]

> 
> A package for .net core is up on nuget.

So you are saying that nuget-ing .Net core would be a workable pre-requisite for
Rx on mono?


From jcasale at activenetwerx.com  Thu Jan 12 00:20:07 2017
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Thu, 12 Jan 2017 05:20:07 +0000
Subject: reactiveX vs Async
In-Reply-To: <0a41fd4a-e51a-4f29-baf8-312cbb85f30f@googlegroups.com>
References: <c7309382-f8ed-49a4-bd41-2fbdce422852@googlegroups.com>
 <a42964f6-f224-4039-b893-e5d7d227656a@googlegroups.com>
 <4062a277404f4823bf0baea1ae76dd8f@activenetwerx.com>
 <mailman.463.1484184001.2395.python-list@python.org>
 <93f66f14-c9ee-446e-9996-3971e96509f7@googlegroups.com>
 <aef27b8cde514b1982b6df0cc9eeafd4@activenetwerx.com>
 <mailman.467.1484187431.2395.python-list@python.org>
 <0a41fd4a-e51a-4f29-baf8-312cbb85f30f@googlegroups.com>
Message-ID: <a6c6225ac4e249ea93872f84120f17da@activenetwerx.com>

> So you are saying that nuget-ing .Net core would be a workable pre-requisite for
> Rx on mono?

Microsoft open sourced .net a while ago. With that came the movement to
bring .net to other platforms.

https://en.wikipedia.org/wiki/.NET_Framework#.NET_Core

As its currently being heavily developed, it only provides a subset of the full
.net base class library but its covering more ground constantly. A good intro
into what is covered is https://blogs.msdn.microsoft.com/dotnet/2016/09/26/introducing-net-standard/

So you can install the sdk and runtime on many supported Linux versions,
a mac or Windows. Get it at https://www.microsoft.com/net/download/core

Then use your text editor of choice, or something like visual studio code (another
free offering that supports multiple platforms), add the nuget package and hack
away on your platform of choice;).

jlc

From metal.suomi at gmail.com  Thu Jan 12 00:36:54 2017
From: metal.suomi at gmail.com (metal.suomi at gmail.com)
Date: Wed, 11 Jan 2017 21:36:54 -0800 (PST)
Subject: just started
In-Reply-To: <mailman.168.1482159623.2322.python-list@python.org>
References: <7e1190f3-e5be-4a39-ad68-35abb9832653@googlegroups.com>
 <CAPTjJmqumgxdPunBnQkL6C93i9-ZOAqDB-gOMyJ_Oqqjvcd7Yg@mail.gmail.com>
 <mailman.120.1481864161.2322.python-list@python.org>
 <b7b8beab-86ae-42b3-93bf-e005bb144ee2@googlegroups.com>
 <CAG93HwFV3PQY6hX6CL=sR1_-yo4ijDthNvaaSOv4YxbWtuta5A@mail.gmail.com>
 <mailman.168.1482159623.2322.python-list@python.org>
Message-ID: <e3381038-b278-4030-9391-7ab84ad7a6d4@googlegroups.com>

along the above discussion, resuming my python after the Xmas break (hope you had a nice one!)

I want to install a number of scientific libraries, but I'm confused which packages it contains what. 

1) I see on scipy.org that scipy contains scipy library (fine, it makes sense), along with other ones  (numpy, matplotlib ....). So, I would guess that the following command 

pip install --user scipy

install all the libraries I need, but instead it seems that I need to specify them too? I.e. to install them I need to name them

pip install --user scipy numpy matplotlib etc... etc...
(of course, I guess I can equivalently use the command python3.5 -m pip install --user scipy numpy matplotlib .... right?)

2) I have already install matplotlib time ago. So, in the above commands I can avoid to add matplotlib, or I can included and a new installation will be overwritten, correct?

Thanks! 


From antoon.pardon at rece.vub.ac.be  Thu Jan 12 03:49:18 2017
From: antoon.pardon at rece.vub.ac.be (Antoon Pardon)
Date: Thu, 12 Jan 2017 09:49:18 +0100
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <001f01d26c5e$13762080$27b23dae@sambora>
References: <001f01d26c5e$13762080$27b23dae@sambora>
Message-ID: <3e3e7166-dc5f-2df2-b8d8-3aca4b1c3cf7@rece.vub.ac.be>

Op 11-01-17 om 23:57 schreef Deborah Swanson:
>
>> What are we supposed to do when somebody asks a question based on an
>> obvious mistake? Assume that they're a quick learner who has probably 
>> already worked out their mistake and doesn't need an answer? That 
>> would certainly make our life easier: we can just ignore everybody's 
>> questions.
> No, of course not. My advice to people who want to help is to not assume
> that you know what the question asker does and doesn't know, and just
> answer the questions without obsessing about what they know.

With all respect, such an answer betrays not much experience on this
list. Half the time answering in this way would mean making very little
progress in actually helping the person. There is an important difference
in trying to help someone and just answering his questions. And your
advice may be the best way to help someone like you but not everyone
is like you. A lot of people have been helped by a remark that didn't
answer the question.

>  If that's
> impossible because they have something so wrong that you don't know what
> they're asking, that would be a good time to point it out and give them
> a chance to correct it.

It is rarely a question of impossibility. It often enough is a sense
that the person asking the question is approaching the problem from
the wrong side. Often enough that sense is correct, often enough that
sense is wrong. All the participants can do is take a clue from the
question and then guess what respons would help this person best.

Nobody can expect that this list will treat their questions in a way
that suits their personal style.

-- 
Antoon Pardon




From python at deborahswanson.net  Thu Jan 12 04:26:38 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Thu, 12 Jan 2017 01:26:38 -0800
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <3e3e7166-dc5f-2df2-b8d8-3aca4b1c3cf7@rece.vub.ac.be>
Message-ID: <001301d26cb5$fa51c930$27b23dae@sambora>

Antoon Pardon wrote, on January 12, 2017 12:49 AM
> 
> Op 11-01-17 om 23:57 schreef Deborah Swanson:
> >
> >> What are we supposed to do when somebody asks a question based on
an 
> >> obvious mistake? Assume that they're a quick learner who has
probably 
> >> already worked out their mistake and doesn't need an answer? That 
> >> would certainly make our life easier: we can just ignore
everybody's 
> >> questions.
> > No, of course not. My advice to people who want to help is to not 
> > assume that you know what the question asker does and doesn't know, 
> > and just answer the questions without obsessing about what 
> they know.
> 
> With all respect, such an answer betrays not much experience 
> on this list. Half the time answering in this way would mean 
> making very little progress in actually helping the person. 
> There is an important difference in trying to help someone 
> and just answering his questions. And your advice may be the 
> best way to help someone like you but not everyone is like 
> you. A lot of people have been helped by a remark that didn't 
> answer the question.

It's true, I've only been on this list a few weeks, although I've seen
and been on the receiving end of the kind of "help" that feels more like
being sneered at than help. Not on this list, but on Linux and similar
lists. There does seem to be a "tough love" approach to "helping"
people, and I haven't seen that it really helped that much, in other
places that I've seen it in action over a period of time.  I'm willing
though to just see how it works on this list. Since I've been here, I
haven't seen people come back who get that kind of approach, but a few
weeks is too short a time to draw conclusions. Still, when people who
need help don't come right back, that should be a first clue that they
didn't get it.
 
> >  If that's
> > impossible because they have something so wrong that you don't know 
> > what they're asking, that would be a good time to point it out and 
> > give them a chance to correct it.
> 
> It is rarely a question of impossibility. It often enough is 
> a sense that the person asking the question is approaching 
> the problem from the wrong side. Often enough that sense is 
> correct, often enough that sense is wrong. All the 
> participants can do is take a clue from the question and then 
> guess what respons would help this person best.

This sounds right to me. Any list or forum that fields questions has the
problem of understanding the questioner who's writing in. Any strategy
that briges that gap seems like a good one to me.

> Nobody can expect that this list will treat their questions 
> in a way that suits their personal style.
> 
> -- 
> Antoon Pardon
> 
> 
Oh, I'm sure that's true, though I do think more direct question asking
and answering is always helpful. Communication in lists and forums is
somewhat in the dark, because there's so little context in many of the
conversations. Questions (and waiting for the answers before responding)
are an excellent way to fill in some of the dark spaces.



From ansu.igit at gmail.com  Thu Jan 12 05:26:30 2017
From: ansu.igit at gmail.com (Ansuman Suryaprakash)
Date: Thu, 12 Jan 2017 02:26:30 -0800 (PST)
Subject: need help getting error when trying selenium with python
Message-ID: <1c47379c-cf9b-40e0-a288-f5385317d118@googlegroups.com>

pyhton version 3.5
selenium version 3.0.2
firefox version 50.1.0


pyhton code:

from selenium import webdriver

browser = webdriver.Firefox()
browser.get('http://127.0.0.1:8000')

assert 'Django' in browser.title

Error:

D:\django_learning_TDD>py functional_tests.py
Traceback (most recent call last):
  File "functional_tests.py", line 3, in <module>
    browser = webdriver.Firefox()
  File "C:\Users\Subhasish\AppData\Local\Programs\Python\Python35-32\lib\site-pa
ckages\selenium\webdriver\firefox\webdriver.py", line 140, in __init__
    self.service.start()
  File "C:\Users\Subhasish\AppData\Local\Programs\Python\Python35-32\lib\site-packages\selenium\webdriver\common\service.py", line 102, in start
    raise WebDriverException("Can not connect to the Service %s" % self.path)
selenium.common.exceptions.WebDriverException: Message: Can not connect to the Service geckodriver


Can someonr help me with getting rid of the above error


From marko at pacujo.net  Thu Jan 12 05:27:34 2017
From: marko at pacujo.net (Marko Rauhamaa)
Date: Thu, 12 Jan 2017 12:27:34 +0200
Subject: Using namedtuples field names for column indices in a list of
 lists
References: <3e3e7166-dc5f-2df2-b8d8-3aca4b1c3cf7@rece.vub.ac.be>
 <001301d26cb5$fa51c930$27b23dae@sambora>
 <mailman.471.1484213203.2395.python-list@python.org>
Message-ID: <87o9zck1yh.fsf@elektro.pacujo.net>

"Deborah Swanson" <python at deborahswanson.net>:

> I've only been on this list a few weeks, although I've seen and been
> on the receiving end of the kind of "help" that feels more like being
> sneered at than help. Not on this list, but on Linux and similar
> lists. There does seem to be a "tough love" approach to "helping"
> people,

An instructive anecdote: somebody I know told me he once needed the
definitive list of some websites. He posted a question on the relevant
online forum, but it fell on deaf ears. After some days, he replied to
his own posting saying he had found the list and included the list in
his reply. He knew the list was probably not current, but it served its
purpose: right away he got an angry response pointing out his list was
completely wrong with a link to the up-to-date list.


Marko


From skip.montanaro at gmail.com  Thu Jan 12 07:12:00 2017
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Thu, 12 Jan 2017 06:12:00 -0600
Subject: timers in threaded application
Message-ID: <CANc-5UxNU9tiCVM0cSKZH-wm68TSB-tO+3Xmy=__cA-oyU4o=Q@mail.gmail.com>

I know signals and threads are a bad mix, but I only discovered I was
playing with fire a few minutes ago. I've been using the websocket-client
library (https://pypi.python.org/pypi/websocket-client/) to interact with
another system at work. It implements its own event loop, but doesn't seem
to play nice with others. I used gtk/gobject for years. It implemented
timeouts for you, you could integrate it with other event loops, etc.

As far as I could tell, websocket-client implements none of that. I needed
some timer functionality, so not thinking about it too carefully, I
implemented it using signal.alarm. This worked pretty well, but I was
experiencing mysterious hangs. This morning, looking through the
websocket-client code to see if I'd missed something, I saw that it uses
threads. So, that might be my problem.

I still need timers, and for the moment I'm stuck with this package's event
loop. What options do I have? I'm certainly willing to switch to another
websocket client library if that will make all my problems go away. This is
my first ws experience though, and I inherited some code which used
websocket-client, so just went with what I had.

Thx,

Skip


From rosuav at gmail.com  Thu Jan 12 08:31:01 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 13 Jan 2017 00:31:01 +1100
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <87o9zck1yh.fsf@elektro.pacujo.net>
References: <3e3e7166-dc5f-2df2-b8d8-3aca4b1c3cf7@rece.vub.ac.be>
 <001301d26cb5$fa51c930$27b23dae@sambora>
 <mailman.471.1484213203.2395.python-list@python.org>
 <87o9zck1yh.fsf@elektro.pacujo.net>
Message-ID: <CAPTjJmraJtcm90XT3wmtcOM0KGtsU2dVoz94tg+QCDzBVKCRXA@mail.gmail.com>

On Thu, Jan 12, 2017 at 9:27 PM, Marko Rauhamaa <marko at pacujo.net> wrote:
> An instructive anecdote: somebody I know told me he once needed the
> definitive list of some websites. He posted a question on the relevant
> online forum, but it fell on deaf ears. After some days, he replied to
> his own posting saying he had found the list and included the list in
> his reply. He knew the list was probably not current, but it served its
> purpose: right away he got an angry response pointing out his list was
> completely wrong with a link to the up-to-date list.

There's a reason for that. Inaccurate information is worse than none
at all, because it's indistinguishable from accurate information
without deep analysis. Also, often someone won't know the correct
answer, but will recognize a wrong answer. In correcting the record,
you come a bit closer to the truth. Sometimes all it takes is one
wrong answer, and the discussion kicks off.

ChrisA


From info at wingware.com  Thu Jan 12 08:49:58 2017
From: info at wingware.com (Wingware)
Date: Thu, 12 Jan 2017 08:49:58 -0500
Subject: ANN: Wing IDE 6.0.1 released
Message-ID: <58778986.8060509@wingware.com>

Hi,

We've just released Wing IDE 6.0.1 which improves remote host 
configuration, adds remote development support for 32-bit Linux and 
older 64-bit Linux systems, fixes stability problems affecting some 
users, and makes many other improvements.  For details on this release, 
see the change log at http://wingware.com/pub/wingide/6.0.1/CHANGELOG.txt

Wing IDE 6 is the latest major release of Wingware's Python IDE that 
adds many new features, introduces a new annual license option, and 
makes some changes to the product line.

New Features

  * Improved Multiple Selections:  Quickly add selections and edit them
    all at once
  * Easy Remote Development:  Work seamlessly on remote Linux, OS X, and
    Raspberry Pi systems
  * Debugging in the Python Shell:  Reach breakpoints and exceptions in
    (and from) the Python Shell
  * Recursive Debugging:  Debug code invoked in the context of stack
    frames that are already being debugged
  * PEP 484 and PEP 526 Type Hinting:  Inform Wing's static analysis
    engine of types it cannot infer
  * Support for Python 3.6 and Stackless 3.4:  Use async and other new
    language features
  * Optimized debugger:  Run faster, particularly in multi-process and
    multi-threaded code
  * Support for OS X full screen mode:  Zoom to a virtual screen, with
    auto-hiding menu bar
  * Added a new One Dark color palette:  Enjoy the best dark display
    style yet
  * Updated French and German localizations:  Thanks to Jean Sanchez,
    Laurent Fasnacht, and Christoph Heitkamp

For a much more detailed overview of new features see the release notice 
at http://wingware.com/news/2017-01-10

Annual Use License Option

Wing 6 adds the option of purchasing a lower-cost expiring annual 
license for Wing IDE Pro.  An annual license includes access to all 
available Wing IDE versions while it is valid, and then ceases to 
function if it is now renewed.  Pricing for annual licenses is US$ 
179/user for Commercial Use and US$ 69/user for Non-Commercial Use.

Perpetual licenses for Wing IDE will continue to be available at the 
same pricing.

The cost of extending Support+Upgrades subscriptions on Non-Commercial 
Use perpetual licenses for Wing IDE Pro has also been dropped from US$ 
89 to US$ 39 per user.

For details, see https://wingware.com/store/purchase

Wing Personal is Free

Wing IDE Personal is now free and no longer requires a license to run. 
  It now also includes the Source Browser, PyLint, and OS Commands 
tools, and supports the scripting API and Perspectives.

However, Wing Personal does not include Wing Pro's advanced editing, 
debugging, testing and code management features, such as remote host 
access, refactoring, find uses, version control, unit testing, 
interactive debug probe, multi-process and child process debugging, move 
program counter, conditional breakpoints, debug watch, 
framework-specific support (for matplotlib, Django, and others), find 
symbol in project, and other features.

Links

Release notice: http://wingware.com/news/2017-01-10
Free trial: http://wingware.com/wingide/trial
Downloads: http://wingware.com/downloads
Feature list: http://wingware.com/wingide/features
Buy: http://wingware.com/store/purchase
Upgrade: 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 iranna.gani28 at gmail.com  Thu Jan 12 08:58:02 2017
From: iranna.gani28 at gmail.com (Iranna Mathapati)
Date: Thu, 12 Jan 2017 19:28:02 +0530
Subject: Find and append file path
Message-ID: <CAA4=HD4psQPzNhaTOz+m_DJCEYbwynqEGnE2uwYxgXNPu23N=w@mail.gmail.com>

Hi Team,

How to append file path and find the latest folder according to the latest
date:

CLI input :"/root/user/branches/xyz"

i want to find latest file within CLI input path and append to given CLI
path

Example:
CLI Input: /root/user/branches/xyz

find latest file and append to CLI path:
"/root/user/branches/xyz/Apple"


From rhodri at kynesim.co.uk  Thu Jan 12 09:44:17 2017
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Thu, 12 Jan 2017 14:44:17 +0000
Subject: Find and append file path
In-Reply-To: <CAA4=HD4psQPzNhaTOz+m_DJCEYbwynqEGnE2uwYxgXNPu23N=w@mail.gmail.com>
References: <CAA4=HD4psQPzNhaTOz+m_DJCEYbwynqEGnE2uwYxgXNPu23N=w@mail.gmail.com>
Message-ID: <9938851c-9a95-016f-1cc0-14859845d78c@kynesim.co.uk>

On 12/01/17 13:58, Iranna Mathapati wrote:
> Hi Team,
>
> How to append file path and find the latest folder according to the latest
> date:
>
> CLI input :"/root/user/branches/xyz"
>
> i want to find latest file within CLI input path and append to given CLI
> path
>
> Example:
> CLI Input: /root/user/branches/xyz
>
> find latest file and append to CLI path:
> "/root/user/branches/xyz/Apple"
>

Use os.scandir() to list whatever is in the directory, DirEntry.is_dir() 
will tell you if an entry is itself a directory, and DirEntry.stat() 
will let you get at the directory's various time stats.  Which attribute 
you want depends on exactly what you mean by "the latest folder 
according to the latest date".  Then just use your favourite means to 
join the directory name you selected to the original path.

-- 
Rhodri James *-* Kynesim Ltd


From python.list at tim.thechases.com  Thu Jan 12 10:39:34 2017
From: python.list at tim.thechases.com (Tim Chase)
Date: Thu, 12 Jan 2017 09:39:34 -0600
Subject: Find and append file path
In-Reply-To: <CAA4=HD4psQPzNhaTOz+m_DJCEYbwynqEGnE2uwYxgXNPu23N=w@mail.gmail.com>
References: <CAA4=HD4psQPzNhaTOz+m_DJCEYbwynqEGnE2uwYxgXNPu23N=w@mail.gmail.com>
Message-ID: <20170112093934.5689207a@bigbox.christie.dr>

On 2017-01-12 19:28, Iranna Mathapati wrote:
> Example:
> CLI Input: /root/user/branches/xyz
> 
> find latest file and append to CLI path:
> "/root/user/branches/xyz/Apple"


I've used something like the below to find the most recent file in a
directory tree (it also works for pulling other attributes like the
file-size from os.stat() results).

-tkc


import os
from operator import attrgetter

def dir_iter(root):
    for fullpath in (
            os.path.join(path, dir_)
            for path, dirs, files in os.walk(root)
            for dir_ in dirs
            ):
        if os.path.isdir(fullpath):
            yield fullpath

def find_latest(root,
        which_time=attrgetter("st_mtime")
        ):
    return max(dir_iter(root),
        key=lambda fullpath: which_time(os.stat(fullpath))
        )

if __name__ == "__main__":
    from sys import argv
    if len(argv) > 1:
        root = argv[1]
    else:
        root = '.'
    print(find_latest(root))
    print(find_latest(root, which_time=attrgetter("st_ctime")))


From josemsuarezsierra at gmail.com  Thu Jan 12 11:07:31 2017
From: josemsuarezsierra at gmail.com (=?UTF-8?Q?Jos=C3=A9_Manuel_Su=C3=A1rez_Sierra?=)
Date: Thu, 12 Jan 2017 08:07:31 -0800 (PST)
Subject: Doubt with matrix
Message-ID: <eb36d051-b6ac-42fe-b7f6-0c3f1bf0506d@googlegroups.com>

Hello, I want to  go over matrix indexs with this code:
def comparador2(a, b):
    c3 = ["0"]  # variables
    x = -1  # contador de letras aniadidas a c3
    i = 0  # contador bucle secuencia a
    j = 0  # contador bucle secuencia b
    l1 = len(a)
    l2 = len(b)
    cont = []  # contador de ciclos poner primer termino a 0
    k = -1  # contador de 0 y 1 aniadidos a cont

    if l1 > l2:  # metodo de la burbuja que elige la secuencia mas larga REVISAR puede ser alreves
        aux = a
        a = b
        b = aux

    for a[i] in a:  # en la secuencia1 recorro los elementos

            for b[j] in b :

                if a[i] == b[j] and i <= l1 and j <= l2:  # Si el elemento i de la seq1 es igual que el elemento j de la seq2, y el numero de elementos en i y j es menor o igual que la longitud de las secuencias 1 y 2
                    c3.append(a[i])  # se aniade el elemento comun a la lista c3
                    x = x + 1
                    k = k + 1
                    j = j + 1  # se pasa el elemento siguiente de la seq2
                    i = i + 1  # se pasa el elemento siguiente de la seq1
                    cont.append(1)



                elif a[i] != b[
                    j] and i <= l1 and j <= l2:  # si no coinciden estos elementos se pasa al siguiente elemento de la lista 2
                    j = j + 1
                    k = k + 1
                    cont.append(0)
                    if cont[k] == 0 and cont[k - 1] == 1 and cont[k - 2] == 0 and k >= 2:
                        i = i - 1
                        j = j - 1
                    else:
                        k = k + 1
                        cont.append(0)
                        if i == l2:
                            i = i + 1
                            j = 0


    return c3

and this issue is prompted:
IndexError: list assignment index out of range

How could I fix it?

Thank you for your assistance


From bgailer at gmail.com  Thu Jan 12 11:33:43 2017
From: bgailer at gmail.com (Bob Gailer)
Date: Thu, 12 Jan 2017 11:33:43 -0500
Subject: Doubt with matrix
In-Reply-To: <eb36d051-b6ac-42fe-b7f6-0c3f1bf0506d@googlegroups.com>
References: <eb36d051-b6ac-42fe-b7f6-0c3f1bf0506d@googlegroups.com>
Message-ID: <CAP1rxO7+u8ekNxQ5yY8d=WAg=n21CjEYezB89e7KztsLsez-Zw@mail.gmail.com>

Always Post the entire traceback. That will show us the line of code that
raised the error, as well as the sequence of function calls involved.

On Jan 12, 2017 11:10 AM, "Jos? Manuel Su?rez Sierra" <
josemsuarezsierra at gmail.com> wrote:

> Hello, I want to  go over matrix indexs with this code:
> def comparador2(a, b):
>     c3 = ["0"]  # variables
>     x = -1  # contador de letras aniadidas a c3
>     i = 0  # contador bucle secuencia a
>     j = 0  # contador bucle secuencia b
>     l1 = len(a)
>     l2 = len(b)
>     cont = []  # contador de ciclos poner primer termino a 0
>     k = -1  # contador de 0 y 1 aniadidos a cont
>
>     if l1 > l2:  # metodo de la burbuja que elige la secuencia mas larga
> REVISAR puede ser alreves
>         aux = a
>         a = b
>         b = aux
>
>     for a[i] in a:  # en la secuencia1 recorro los elementos
>
>             for b[j] in b :
>
>                 if a[i] == b[j] and i <= l1 and j <= l2:  # Si el elemento
> i de la seq1 es igual que el elemento j de la seq2, y el numero de
> elementos en i y j es menor o igual que la longitud de las secuencias 1 y 2
>                     c3.append(a[i])  # se aniade el elemento comun a la
> lista c3
>                     x = x + 1
>                     k = k + 1
>                     j = j + 1  # se pasa el elemento siguiente de la seq2
>                     i = i + 1  # se pasa el elemento siguiente de la seq1
>                     cont.append(1)
>
>
>
>                 elif a[i] != b[
>                     j] and i <= l1 and j <= l2:  # si no coinciden estos
> elementos se pasa al siguiente elemento de la lista 2
>                     j = j + 1
>                     k = k + 1
>                     cont.append(0)
>                     if cont[k] == 0 and cont[k - 1] == 1 and cont[k - 2]
> == 0 and k >= 2:
>                         i = i - 1
>                         j = j - 1
>                     else:
>                         k = k + 1
>                         cont.append(0)
>                         if i == l2:
>                             i = i + 1
>                             j = 0
>
>
>     return c3
>
> and this issue is prompted:
> IndexError: list assignment index out of range
>
> How could I fix it?
>
> Thank you for your assistance
> --
> https://mail.python.org/mailman/listinfo/python-list
>


From __peter__ at web.de  Thu Jan 12 11:59:31 2017
From: __peter__ at web.de (Peter Otten)
Date: Thu, 12 Jan 2017 17:59:31 +0100
Subject: Doubt with matrix
References: <eb36d051-b6ac-42fe-b7f6-0c3f1bf0506d@googlegroups.com>
Message-ID: <o58clf$nqh$1@blaine.gmane.org>

Jos? Manuel Su?rez Sierra wrote:

> Hello, I want to  go over matrix indexs with this code:
> def comparador2(a, b):
>     c3 = ["0"]  # variables
>     x = -1  # contador de letras aniadidas a c3
>     i = 0  # contador bucle secuencia a
>     j = 0  # contador bucle secuencia b
>     l1 = len(a)
>     l2 = len(b)
>     cont = []  # contador de ciclos poner primer termino a 0
>     k = -1  # contador de 0 y 1 aniadidos a cont
> 
>     if l1 > l2:  # metodo de la burbuja que elige la secuencia mas larga
>     REVISAR puede ser alreves

In Python there's a cool way to swap values without an explicit helper 
variable:

          a, b = b, a

>         aux = a
>         a = b
>         b = aux

OK, now you have swapped a and b, but not their respective lengths l1 and 
l2...
 
>     for a[i] in a:  # en la secuencia1 recorro los elementos

Do you really want to modify a[i] on every iteration? Most certainly not. 
Try to use the normal way with just a name, e. g.

      for entry_a in a:
          ...

Then use entry_a instead of a[i] for your comparison in the body of the for-
loop. With that approach it's impossible to get an IndexError.
If you still need the index to alter an entry in the list -- enumerate() is 
your friend:

for index_a, entry_a in enumerate(a):
    ...

Again it's unlikely that you will get an IndexError.
 
>             for b[j] in b :
> 
>                 if a[i] == b[j] and i <= l1 and j <= l2:  # Si el elemento
>                 i de la seq1 es igual que el elemento j de la seq2, y el
>                 numero de elementos en i y j es menor o igual que la
>                 longitud de las secuencias 1 y 2
>                     c3.append(a[i])  # se aniade el elemento comun a la
>                     lista c3 x = x + 1
>                     k = k + 1
>                     j = j + 1  # se pasa el elemento siguiente de la seq2
>                     i = i + 1  # se pasa el elemento siguiente de la seq1
>                     cont.append(1)
> 
> 
> 
>                 elif a[i] != b[
>                     j] and i <= l1 and j <= l2:  # si no coinciden estos
>                     elementos se pasa al siguiente elemento de la lista 2
>                     j = j + 1 k = k + 1
>                     cont.append(0)
>                     if cont[k] == 0 and cont[k - 1] == 1 and cont[k - 2]
>                     == 0 and k >= 2:
>                         i = i - 1
>                         j = j - 1
>                     else:
>                         k = k + 1
>                         cont.append(0)
>                         if i == l2:
>                             i = i + 1
>                             j = 0
> 
> 
>     return c3
> 
> and this issue is prompted:
> IndexError: list assignment index out of range
> 
> How could I fix it?
> 
> Thank you for your assistance




From __peter__ at web.de  Thu Jan 12 12:32:02 2017
From: __peter__ at web.de (Peter Otten)
Date: Thu, 12 Jan 2017 18:32:02 +0100
Subject: Find and append file path
References: <CAA4=HD4psQPzNhaTOz+m_DJCEYbwynqEGnE2uwYxgXNPu23N=w@mail.gmail.com>
 <20170112093934.5689207a@bigbox.christie.dr>
Message-ID: <o58eie$8g5$1@blaine.gmane.org>

Tim Chase wrote:

> def dir_iter(root):
>     for fullpath in (
>             os.path.join(path, dir_)
>             for path, dirs, files in os.walk(root)
>             for dir_ in dirs
>             ):
>         if os.path.isdir(fullpath):
>             yield fullpath

Why did you add an explicit isdir() check? My understanding is that the 
names in dirs are known to be directories.




From python.list at tim.thechases.com  Thu Jan 12 12:50:39 2017
From: python.list at tim.thechases.com (Tim Chase)
Date: Thu, 12 Jan 2017 11:50:39 -0600
Subject: Find and append file path
In-Reply-To: <o58eie$8g5$1@blaine.gmane.org>
References: <CAA4=HD4psQPzNhaTOz+m_DJCEYbwynqEGnE2uwYxgXNPu23N=w@mail.gmail.com>
 <20170112093934.5689207a@bigbox.christie.dr>
 <o58eie$8g5$1@blaine.gmane.org>
Message-ID: <20170112115039.3d335097@bigbox.christie.dr>

On 2017-01-12 18:32, Peter Otten wrote:
> Why did you add an explicit isdir() check? My understanding is that
> the names in dirs are known to be directories.

Ah, right.  The code I had laying around that did something similar
but processes both the dirs and the files, so when the OP asked for
just dirs, I ended up with both belt-and-suspenders changes to it.

So that isdir() check could readily be removed.

-tkc




From kulakov.ilya at gmail.com  Thu Jan 12 20:20:49 2017
From: kulakov.ilya at gmail.com (Ilya Kulakov)
Date: Thu, 12 Jan 2017 17:20:49 -0800 (PST)
Subject: Automatically restore virtualenv in Terminal.app on macOS (zsh, bash)
Message-ID: <727d9c09-be19-44cc-ae47-75561b4dccb4@googlegroups.com>

Today I discovered that one can customize session restoration in Terminal.app
by defining the shell_session_save_user_state function.

Here is a script that restores active virtualenv, e.g. after you reboot your machine:

    https://gist.github.com/Kentzo/185e4eab382bbcf1f0a9738a28128dce

It's written for ZSH, but it's fairly simple to port it to bash: you don't even need plugin,
since session management is supported out of the box.

Here is a plugin for oh-my-zsh:

    https://github.com/Kentzo/oh-my-zsh/tree/master/plugins/session


From torriem at gmail.com  Thu Jan 12 20:40:57 2017
From: torriem at gmail.com (Michael Torrie)
Date: Thu, 12 Jan 2017 18:40:57 -0700
Subject: Using namedtuples field names for column indices in a list of
 lists
In-Reply-To: <001301d26cb5$fa51c930$27b23dae@sambora>
References: <001301d26cb5$fa51c930$27b23dae@sambora>
Message-ID: <e21f12cf-a874-1f16-3da8-a188f59a603a@gmail.com>

On 01/12/2017 02:26 AM, Deborah Swanson wrote:
> It's true, I've only been on this list a few weeks, although I've seen
> and been on the receiving end of the kind of "help" that feels more like
> being sneered at than help. Not on this list, but on Linux and similar
> lists. There does seem to be a "tough love" approach to "helping"
> people, and I haven't seen that it really helped that much, in other
> places that I've seen it in action over a period of time.  

If you go down a wrong path, people are going to try to warn you.  For
example, you were told several times, no that object really is a list,
yet you argued with them on that point for several posts.  Tough love or
sneering? No, absolutely not.  Communication difficulties?  Yes!  But
not even close to wholly the fault of those who were trying to assist
you. If you haven't been helped, it's not for lack of their trying.

> I'm willing
> though to just see how it works on this list. Since I've been here, I
> haven't seen people come back who get that kind of approach, but a few
> weeks is too short a time to draw conclusions. Still, when people who
> need help don't come right back, that should be a first clue that they
> didn't get it.

Fortunately this list is pretty friendly and open to newbies.  And
long-time posters have no problem telling other long-time posters when
they do cross the line into bullying or trolling territory.

Fortunately I've seen nothing but people wanting to help you with your
ventures in Python programming responding to your queries, which I'm
gratified to see.  And many many newbies have been helped in their
explorations of Python land.


From dieter at handshake.de  Fri Jan 13 04:23:51 2017
From: dieter at handshake.de (dieter)
Date: Fri, 13 Jan 2017 10:23:51 +0100
Subject: timers in threaded application
References: <CANc-5UxNU9tiCVM0cSKZH-wm68TSB-tO+3Xmy=__cA-oyU4o=Q@mail.gmail.com>
Message-ID: <87lguf9uu0.fsf@handshake.de>

Skip Montanaro <skip.montanaro at gmail.com> writes:
> ...
> I still need timers, and for the moment I'm stuck with this package's event
> loop. What options do I have?

If the activities are really run in separate threads (such that
an event processing can take arbitrary time without much
affecting the processing of other events) and "select.select"
is available on your platform (e.g. some *nix* platform),
you might be able to use its "timeout" parameter. This is
particularly useful when what you want to timeout are I/O operations.

If what you want to timeout are not I/O operations, you can have a
look at "threading.Timer". It uses a separate thread, lets it wait
a specified time and then starts a specified function, unless
"cancel"ed. In this case, you must find some way to abort a pending
event processing due to a timeout and let the timer function use it
for abortion.



From haraldnordgren at gmail.com  Fri Jan 13 04:27:10 2017
From: haraldnordgren at gmail.com (haraldnordgren at gmail.com)
Date: Fri, 13 Jan 2017 01:27:10 -0800 (PST)
Subject: A detailed description on virtualenv's packaging dependecies? (pip,
 easy_install, wheel, setuptools, distlib, etc.)
Message-ID: <05080bd7-5903-4621-9cc5-e5c9be04e80d@googlegroups.com>

I was working on a bugfix for Virtualenv, regarding very long shebang lines that are breaking things. In the process, I realized that if I want really fix to my particular issue it likely needs to be done on the lower level of Python package management. I started with pip, moved to setuptools and now set my sight on distlib.

Can someone describe the specific dependencies of all the *packaging* libraries that `virtualenv` uses? And the dependencies between them?

I believe that virtualenv directly imports `pip`, `easy_install` and `wheel`. Those in turn import `setuptools` and `distlib`. Am I so lucky as to assume that distlib in the lowest-level library used by all the rest in virtualenv for packages?


From haraldnordgren at gmail.com  Fri Jan 13 04:27:46 2017
From: haraldnordgren at gmail.com (haraldnordgren at gmail.com)
Date: Fri, 13 Jan 2017 01:27:46 -0800 (PST)
Subject: Running Virtualenv with a custom distlib?
Message-ID: <2bc1125c-eb70-49bc-bd90-ebeaa9741258@googlegroups.com>

I want to do some development on `distlib`, and in the process run the code via `virtualenv` which has distlib as a dependency.

That is, not run the process inside a virtualenv, but run virtualenv's code using a custom dependency. What are the steps I need to go through to achieve this?

It seems to me that normal package management (`pip`) is not possible here.


From steve+python at pearwood.info  Fri Jan 13 05:46:34 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Fri, 13 Jan 2017 21:46:34 +1100
Subject: Byte-run: a Python interpreter written in Python
Message-ID: <5878b00c$0$1588$c3e8da3$5496439d@news.astraweb.com>


http://aosabook.org/en/500L/a-python-interpreter-written-in-python.html


-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From adnan.connexus at gmail.com  Fri Jan 13 06:38:33 2017
From: adnan.connexus at gmail.com (adnan.connexus at gmail.com)
Date: Fri, 13 Jan 2017 03:38:33 -0800 (PST)
Subject: matrix from matrix
Message-ID: <fb5f7ed4-4902-4c20-b5cd-4d86a923c2d1@googlegroups.com>

Hi all,

I have just started python coding  and have ran into my first brick wall.  Can some one please assist me with the following query  ?

 I have two Matrices:
1 ? masterMatrix ? A 2d matrix containing items in the rows and time as the columns column headers (time beginning from 00:00 to 23:45 at every 15 minutes interval (96 columns e.g. 00:00 | 00:15 . . . .23:45). this matrix provides a value of each item in the list a every 14 minutes. 

2 ? subMatrix ? A matrix which has to be populate based on selected items and times from masterMatrix 

What would be the fastest way to first initialise the subMatrix  and populate the workingTable based on the matching values in masterTable.

best regards,
Shei


From __peter__ at web.de  Fri Jan 13 10:20:23 2017
From: __peter__ at web.de (Peter Otten)
Date: Fri, 13 Jan 2017 16:20:23 +0100
Subject: matrix from matrix
References: <fb5f7ed4-4902-4c20-b5cd-4d86a923c2d1@googlegroups.com>
Message-ID: <o5ar7l$c01$1@blaine.gmane.org>

adnan.connexus at gmail.com wrote:

> Hi all,
> 
> I have just started python coding  and have ran into my first brick wall. 
> Can some one please assist me with the following query  ?
> 
>  I have two Matrices:
> 1 ? masterMatrix ? A 2d matrix containing items in the rows and time as
> the columns column headers (time beginning from 00:00 to 23:45 at every 15
> minutes interval (96 columns e.g. 00:00 | 00:15 . . . .23:45). this matrix
> provides a value of each item in the list a every 14 minutes.
> 
> 2 ? subMatrix ? A matrix which has to be populate based on selected items
> and times from masterMatrix
> 
> What would be the fastest way to first initialise the subMatrix  and

Forget about "fastest" as long as you have no way.

> populate the workingTable based on the matching values in masterTable.

Give us a bit of code that initialises your master matrix with some toy data 
(3 to 5 rows and columns, say) and that shows what you have tried to build 
the sub-matrix.

Then we can identify your "road block" and help you overcome it.



From steve+python at pearwood.info  Fri Jan 13 10:23:47 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Sat, 14 Jan 2017 02:23:47 +1100
Subject: matrix from matrix
References: <fb5f7ed4-4902-4c20-b5cd-4d86a923c2d1@googlegroups.com>
Message-ID: <5878f104$0$1587$c3e8da3$5496439d@news.astraweb.com>

On Fri, 13 Jan 2017 10:38 pm, adnan.connexus at gmail.com wrote:

> Hi all,
> 
> I have just started python coding  and have ran into my first brick wall. 
> Can some one please assist me with the following query  ?

Not really, because you haven't given us enough information to answer your
questions.


>  I have two Matrices:

What is a matrix? Do you mean a list? A numpy array?

The best thing is to show us the code you already have. We don't need to see
ALL your code, just the relevant part that creates the two matrices.


> 1 ? masterMatrix ? A 2d matrix containing items in the rows and time as
> the columns column headers (time beginning from 00:00 to 23:45 at every 15
> minutes interval (96 columns e.g. 00:00 | 00:15 . . . .23:45). this matrix
> provides a value of each item in the list a every 14 minutes.
> 
> 2 ? subMatrix ? A matrix which has to be populate based on selected items
> and times from masterMatrix

How do you select the items that you want?


> What would be the fastest way to first initialise the subMatrix  and
> populate the workingTable based on the matching values in masterTable.

That's like asking:

"What's the shortest piece of string to tie two things together?"

Um, it depends on which two things, it depends on how secure you need the
tie to be... we need more detail.




-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From skip.montanaro at gmail.com  Fri Jan 13 10:41:38 2017
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Fri, 13 Jan 2017 09:41:38 -0600
Subject: timers in threaded application
In-Reply-To: <87lguf9uu0.fsf@handshake.de>
References: <CANc-5UxNU9tiCVM0cSKZH-wm68TSB-tO+3Xmy=__cA-oyU4o=Q@mail.gmail.com>
 <87lguf9uu0.fsf@handshake.de>
Message-ID: <CANc-5Uz44rTNRe_08F=WryGWZycnZz344daP+nWetGjRmmekTw@mail.gmail.com>

On Fri, Jan 13, 2017 at 3:23 AM, dieter <dieter at handshake.de> wrote:

> If what you want to timeout are not I/O operations, you can have a
> look at "threading.Timer". It uses a separate thread, lets it wait
> a specified time and then starts a specified function, unless
> "cancel"ed.
>

Ooh, hadn't considered that. That would seem to do the trick. I assume the
function to be executed will be run in the timer's thread, so will have to
suitably lock any shared data.

Thx,

Skip


From ian.g.kelly at gmail.com  Fri Jan 13 12:08:57 2017
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 13 Jan 2017 10:08:57 -0700
Subject: Byte-run: a Python interpreter written in Python
In-Reply-To: <5878b00c$0$1588$c3e8da3$5496439d@news.astraweb.com>
References: <5878b00c$0$1588$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CALwzid=OmP3_a-+xW=hF4RnnZ3AATxkdbwb9be1PxwNY7QZvQg@mail.gmail.com>

On Fri, Jan 13, 2017 at 3:46 AM, Steve D'Aprano
<steve+python at pearwood.info> wrote:
>
> http://aosabook.org/en/500L/a-python-interpreter-written-in-python.html

Neat. But not really surprising IMO that it can fit into 500 lines,
since it doesn't handle compiling Python into bytecode (which is the
hard part) and doesn't include libraries. There doesn't seem to be
much purpose to this other than it being a toy project written for a
book.


From michael.s011235 at gmail.com  Fri Jan 13 13:00:05 2017
From: michael.s011235 at gmail.com (Michael S)
Date: Fri, 13 Jan 2017 19:00:05 +0100
Subject: Problem while building Python 3.6 from source.
Message-ID: <CAGGEVu-1x-7b=psOQN39sx_6Yf0MFZmMAB5+-CEisbS0LBUAgQ@mail.gmail.com>

Hello,
I am new to this mailing-list and I really don't know whether this
mail should belong to python-dev. Please tell me, if so.


Unfortunately, I have got the following problem: I wanted to build and
install Python 3.6 from source but did not succeed.
To clarify my situation, I got as an operating system Debian jessie
8.6 and I used the xz compressed source tarball from
https://www.python.org/downloads/release/python-360/.
Concerning the build dependencies: I just executed:
$ sudo apt-get build-dep python3.4 (since 3.6 and 3.5 did not work).
Then I executed ./configure --enable-optimizations and make -j4 (I got 4 cores).
The output of make ended like:
'make: *** [profile-opt] Error 2'.
I had redirected the output and error of the configure and make commands via
$ make -j4 &> /home/username/make_output.txt.
Nevertheless I got an error to the console:
'*** Error in ./python'" free(): invalid next size (normal):
0x00000000015bdf90 ***'.
Due to these error messages (this one and the one at the end of make)
I think the build was not successful.

How to solve this problem?

Of course I could send you the output and error files.

I'd be glad at any help.
-MichaelS


From brettsalyer at gmail.com  Fri Jan 13 13:07:29 2017
From: brettsalyer at gmail.com (brettsalyer at gmail.com)
Date: Fri, 13 Jan 2017 10:07:29 -0800 (PST)
Subject: Software to Control RGB Strips
Message-ID: <739c31a6-bf54-41c9-b5c8-050bbe174ac9@googlegroups.com>

Hey all,

I was debating on getting some RGB light strips for my room. I noticed, from this tutorial:

http://popoklopsi.github.io/RaspberryPi-LedStrip/#!/ws2812


there is a  WS2812x library to run commands that control the RGB strip. Well, I wanted to, instead of running commands through a terminal, create a GUI using python, then exploit the library I mentioned above to create a piece of software that controls my lighting from my Raspberry Pi.

I was going to use Tkinter to create the GUI. 

Now, I'm a pretty beginner programmer, having only taken a C++ course and the Java course I'm in now.

Do I just need to download the WS2812x library, and, then, access that library as I would, say, a header file in C++? In Pythons syntax, of course.

Anything to get me pointed in the right direction would be greatly appreciated! Thanks!


From bc at freeuk.com  Fri Jan 13 13:07:33 2017
From: bc at freeuk.com (BartC)
Date: Fri, 13 Jan 2017 18:07:33 +0000
Subject: Byte-run: a Python interpreter written in Python
In-Reply-To: <mailman.4.1484327381.22298.python-list@python.org>
References: <5878b00c$0$1588$c3e8da3$5496439d@news.astraweb.com>
 <CALwzid=OmP3_a-+xW=hF4RnnZ3AATxkdbwb9be1PxwNY7QZvQg@mail.gmail.com>
 <mailman.4.1484327381.22298.python-list@python.org>
Message-ID: <o5b4u8$dob$1@dont-email.me>

On 13/01/2017 17:08, Ian Kelly wrote:
> On Fri, Jan 13, 2017 at 3:46 AM, Steve D'Aprano
> <steve+python at pearwood.info> wrote:
>>
>> http://aosabook.org/en/500L/a-python-interpreter-written-in-python.html
>
> Neat. But not really surprising IMO that it can fit into 500 lines,

If there are still 120 or so byte-codes, then that's just 4 lines on 
average to implement each byte-code, which is pretty good going.

Even when it turns out that the actual code on github is 1000 lines 
rather than 500! Maybe it grew a bit since the 500 lines was quoted.

But it's still 8 lines per byte-code.

> since it doesn't handle compiling Python into bytecode (which is the
> hard part)

I disagree that that's the hardest part. But it was probably not very 
interesting for this project. Implementing the runtime environment, the 
object system, type-dispatchers, error-handling, symbol tables, garbage 
collection and all the rest would be more challenging.

> and doesn't include libraries. There doesn't seem to be
> much purpose to this other than it being a toy project written for a
> book.

Being educational would be enough of a point.

-- 
Bartc


From tomuxiong at gmx.com  Fri Jan 13 13:12:25 2017
From: tomuxiong at gmx.com (Thomas Nyberg)
Date: Fri, 13 Jan 2017 10:12:25 -0800
Subject: Problem while building Python 3.6 from source.
In-Reply-To: <CAGGEVu-1x-7b=psOQN39sx_6Yf0MFZmMAB5+-CEisbS0LBUAgQ@mail.gmail.com>
References: <CAGGEVu-1x-7b=psOQN39sx_6Yf0MFZmMAB5+-CEisbS0LBUAgQ@mail.gmail.com>
Message-ID: <2efba555-859e-717a-42fb-8daee5497e4e@gmx.com>

On 01/13/2017 10:00 AM, Michael S wrote:
> '*** Error in ./python'" free(): invalid next size (normal):
> 0x00000000015bdf90 ***'.

Are you possibly running out of memory due to the extra concurrent 
compilations?

Cheers,
Thomas



From rosuav at gmail.com  Fri Jan 13 13:19:10 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 14 Jan 2017 05:19:10 +1100
Subject: Problem while building Python 3.6 from source.
In-Reply-To: <CAGGEVu-1x-7b=psOQN39sx_6Yf0MFZmMAB5+-CEisbS0LBUAgQ@mail.gmail.com>
References: <CAGGEVu-1x-7b=psOQN39sx_6Yf0MFZmMAB5+-CEisbS0LBUAgQ@mail.gmail.com>
Message-ID: <CAPTjJmoUm-UUU+8nb7-+jCVFAXqWvkCFm9FufOE8-ZUMDtW6_Q@mail.gmail.com>

On Sat, Jan 14, 2017 at 5:00 AM, Michael S <michael.s011235 at gmail.com> wrote:
> Hello,
> I am new to this mailing-list and I really don't know whether this
> mail should belong to python-dev. Please tell me, if so.

Hi and welcome! This kind of thing is best on this list initially.

> Unfortunately, I have got the following problem: I wanted to build and
> install Python 3.6 from source but did not succeed.
> To clarify my situation, I got as an operating system Debian jessie
> 8.6 and I used the xz compressed source tarball from
> https://www.python.org/downloads/release/python-360/.
> Concerning the build dependencies: I just executed:
> $ sudo apt-get build-dep python3.4 (since 3.6 and 3.5 did not work).

That should be fine; the build dependencies of Python don't tend to
change frequently. Jessie shipped with Python 3.4 but nothing newer,
so there won't be packages for python3.5 or python3.6.

> Then I executed ./configure --enable-optimizations and make -j4 (I got 4 cores).
> The output of make ended like:
> 'make: *** [profile-opt] Error 2'.

That just means that something went wrong. You'd have to scroll up to
find the actual cause of the error.

> I had redirected the output and error of the configure and make commands via
> $ make -j4 &> /home/username/make_output.txt.
> Nevertheless I got an error to the console:
> '*** Error in ./python'" free(): invalid next size (normal):
> 0x00000000015bdf90 ***'.
> Due to these error messages (this one and the one at the end of make)
> I think the build was not successful.
>
> How to solve this problem?
>
> Of course I could send you the output and error files.

The first thing I'd do would be to try a non-optimized build. Set your
current build tree aside and re-extract into a new directory (that
way, when you go back to playing with optimized builds, you don't have
to redo the work), and run configure with no arguments. I'd also be
inclined to run make with no arguments; there've been issues with
parallel builds in enough projects that I've gotten into the habit of
"problem? do it the slow way". If that build also fails, scroll up a
bit and find where stuff failed.

Are you familiar with building programs from source? If not, the best
solution might be to post the entire log, but ideally, you should be
able to skim through the last part of the log and report the actual
problem that's cropping up.

ChrisA


From rosuav at gmail.com  Fri Jan 13 13:24:41 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 14 Jan 2017 05:24:41 +1100
Subject: Software to Control RGB Strips
In-Reply-To: <739c31a6-bf54-41c9-b5c8-050bbe174ac9@googlegroups.com>
References: <739c31a6-bf54-41c9-b5c8-050bbe174ac9@googlegroups.com>
Message-ID: <CAPTjJmoO8Pbj2V-sJrz_kTROO4vtdwCDD_zX7eH2=qGS1Td=tA@mail.gmail.com>

On Sat, Jan 14, 2017 at 5:07 AM,  <brettsalyer at gmail.com> wrote:
> Hey all,
>
> I was debating on getting some RGB light strips for my room. I noticed, from this tutorial:
>
> http://popoklopsi.github.io/RaspberryPi-LedStrip/#!/ws2812
>
>
> there is a  WS2812x library to run commands that control the RGB strip.
>
> Do I just need to download the WS2812x library, and, then, access that library as I would, say, a header file in C++? In Pythons syntax, of course.
>
> Anything to get me pointed in the right direction would be greatly appreciated! Thanks!

Pretty much, yeah. The Python syntax to do that is probably:

import ws2812

although a glance at the examples suggests that the package might be
called "neopixel" instead, which is a bit surprising.

You may be able to skip the download and compilation steps and just run this:

python3 -m pip install rpi_ws281x

I don't know anything about the library itself, but that's the normal
way to install more Python packages. You can find a full list of
packages you can install that way here:

https://pypi.python.org/pypi

There's a lot of them :)

Enjoy!

ChrisA


From ian.g.kelly at gmail.com  Fri Jan 13 13:47:31 2017
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 13 Jan 2017 11:47:31 -0700
Subject: Byte-run: a Python interpreter written in Python
In-Reply-To: <o5b4u8$dob$1@dont-email.me>
References: <5878b00c$0$1588$c3e8da3$5496439d@news.astraweb.com>
 <CALwzid=OmP3_a-+xW=hF4RnnZ3AATxkdbwb9be1PxwNY7QZvQg@mail.gmail.com>
 <mailman.4.1484327381.22298.python-list@python.org>
 <o5b4u8$dob$1@dont-email.me>
Message-ID: <CALwzidnLFjDcD8oqnHmnVALTRMJv-_Trb0a9RvAo-ZHANOgqYg@mail.gmail.com>

On Fri, Jan 13, 2017 at 11:07 AM, BartC <bc at freeuk.com> wrote:
> Even when it turns out that the actual code on github is 1000 lines rather
> than 500! Maybe it grew a bit since the 500 lines was quoted.

I assume they're excluding blank lines, comments and docstrings. And I
don't know whether the 500 lines is a hard limit or if there is a bit
of leeway there.


From bc at freeuk.com  Fri Jan 13 14:25:00 2017
From: bc at freeuk.com (BartC)
Date: Fri, 13 Jan 2017 19:25:00 +0000
Subject: Byte-run: a Python interpreter written in Python
In-Reply-To: <mailman.9.1484333295.22298.python-list@python.org>
References: <5878b00c$0$1588$c3e8da3$5496439d@news.astraweb.com>
 <CALwzid=OmP3_a-+xW=hF4RnnZ3AATxkdbwb9be1PxwNY7QZvQg@mail.gmail.com>
 <mailman.4.1484327381.22298.python-list@python.org>
 <o5b4u8$dob$1@dont-email.me>
 <CALwzidnLFjDcD8oqnHmnVALTRMJv-_Trb0a9RvAo-ZHANOgqYg@mail.gmail.com>
 <mailman.9.1484333295.22298.python-list@python.org>
Message-ID: <o5b9ff$q6c$1@dont-email.me>

On 13/01/2017 18:47, Ian Kelly wrote:
> On Fri, Jan 13, 2017 at 11:07 AM, BartC <bc at freeuk.com> wrote:
>> Even when it turns out that the actual code on github is 1000 lines rather
>> than 500! Maybe it grew a bit since the 500 lines was quoted.
>
> I assume they're excluding blank lines, comments and docstrings. And I
> don't know whether the 500 lines is a hard limit or if there is a bit
> of leeway there.
>

https://github.com/nedbat/byterun/blob/master/byterun/pyvm2.py

github reports 869 sloc from a total of 1044 lines.

But 1000 lines is still small compared with the 220,000 lines of CPython 
(and that was an old version) which is only the C code and nothing else.

If someone wants to experiment with the behaviour of a byte-code, they 
might be able to do with this project (I haven't tried), more easily 
than with the real thing.


-- 
Bartc


From ned at nedbatchelder.com  Fri Jan 13 14:57:32 2017
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Fri, 13 Jan 2017 11:57:32 -0800 (PST)
Subject: Byte-run: a Python interpreter written in Python
In-Reply-To: <mailman.4.1484327381.22298.python-list@python.org>
References: <5878b00c$0$1588$c3e8da3$5496439d@news.astraweb.com>
 <CALwzid=OmP3_a-+xW=hF4RnnZ3AATxkdbwb9be1PxwNY7QZvQg@mail.gmail.com>
 <mailman.4.1484327381.22298.python-list@python.org>
Message-ID: <fb677988-770a-48eb-8ad6-3e272fe80f1f@googlegroups.com>

On Friday, January 13, 2017 at 12:09:52 PM UTC-5, Ian wrote:
> On Fri, Jan 13, 2017 at 3:46 AM, Steve D'Aprano
> <steve+python at pearwood.info> wrote:
> >
> > http://aosabook.org/en/500L/a-python-interpreter-written-in-python.html
> 
> Neat. But not really surprising IMO that it can fit into 500 lines,
> since it doesn't handle compiling Python into bytecode (which is the
> hard part) and doesn't include libraries. There doesn't seem to be
> much purpose to this other than it being a toy project written for a
> book.

I can tell you what its purpose was: it was to verify my understanding
of the execution semantics of Python bytecode.  At the time, coverage.py
analyzed code for possible branches by reading the bytecode.  There are
some very tricky bytecodes, and I wasn't sure that I understood what they
did.

I figured that if I could implement a Python VM, then it would prove that
I understood it, or would shine a light on my misconceptions.

I thought perhaps someone had done it already.  I found Paul Swartz's vm2
code, which was a very similar idea. I refactored it, polished it up, and
extended it, and the result was byterun.

It served its purpose: although it didn't execute everything properly,
there were some twisty bits made clearer by the exercise.  Post-Script:
coverage.py no longer uses bytecode analysis, it uses AST analysis, which
works much better.

Since we're talking about possible purposes: Paul Swartz's original goal
was to sandbox Python execution. I'm not sure that was a realistic goal
for code like this, but that was his goal.

--Ned.


From darcy at VybeNetworks.com  Fri Jan 13 17:24:27 2017
From: darcy at VybeNetworks.com (D'Arcy Cain)
Date: Fri, 13 Jan 2017 17:24:27 -0500
Subject: Extended ASCII
Message-ID: <20aa3bc3-b26d-aa3d-2265-8e3c8d7bdf65@VybeNetworks.com>

I thought I was done with this crap once I moved to 3.x but some 
Winblows machines are still sending what some circles call "Extended 
ASCII".  I have a file that I am trying to read and it is barfing on 
some characters.  For example:

   due to the Qu\xe9bec government

Obviously should be "due to the Qu?bec government".  I can't figure out 
what that encoding is or if it is anything that can even be understood 
outside of M$.  I have tried ascii, cp437, cp858, cp1140, cp1250, 
latin-1, utf8 and others.  None of them recognize that character.  Can 
someone tell me what encoding includes that character please.

Here is the failing code:

with open(sys.argv[1], encoding="latin-1") as fp:
   for ln in fp:
     print(ln)

Traceback (most recent call last):
   File "./load_iff", line 11, in <module>
     print(ln)
UnicodeEncodeError: 'ascii' codec can't encode character '\xe9' in 
position 132: ordinal not in range(128)

I don't understand why the error says "ascii" when I told it to use 
"latin-1".

-- 
D'Arcy J.M. Cain
Vybe Networks Inc.
http://www.VybeNetworks.com/
IM:darcy at Vex.Net VoIP: sip:darcy at VybeNetworks.com


From daviddschool at gmail.com  Fri Jan 13 17:26:54 2017
From: daviddschool at gmail.com (daviddschool at gmail.com)
Date: Fri, 13 Jan 2017 14:26:54 -0800 (PST)
Subject: How can I make a sentinel value NOT be initialized in a class/method
 - OOP?
Message-ID: <c49823f1-3d05-4101-a766-4ac5bca034f4@googlegroups.com>

I am testing out some basic Object Oriented Programming in Python.  The basics: 

-User enters a name 
-While loop with a sentinel value of "quit" will continue entering names until the sentinel value is reached 
-The object is created with the inputted value (NAME and until a sentinel value is entered) 
-the object is then printed out using the constructor __str__ 

In my solution ( I am saying this because someone might have a work around that doesn't include the following below) 
-I want to use __init__ 
-I want to use __str__ 
-I want to use a while loop with a sentinel value 

EXPLANATION: 
I want to have the user enter in their NAME using a while loop, with "quit" being the sentinel value that breaks the loop.  Once the name is entered, an object is created and it is passed into a constructor def __ini__ (self, name) and then I have them return a string value using __str__ for the name entered. 
The issue I am having is that when i enter the sentinel value of QUIT, it gets initialized as the name and printed out.  How can I get around this?  I hope this makes sense.


From random832 at fastmail.com  Fri Jan 13 17:36:11 2017
From: random832 at fastmail.com (Random832)
Date: Fri, 13 Jan 2017 17:36:11 -0500
Subject: Extended ASCII
In-Reply-To: <20aa3bc3-b26d-aa3d-2265-8e3c8d7bdf65@VybeNetworks.com>
References: <20aa3bc3-b26d-aa3d-2265-8e3c8d7bdf65@VybeNetworks.com>
Message-ID: <1484346971.3140184.847206424.09B816FC@webmail.messagingengine.com>

On Fri, Jan 13, 2017, at 17:24, D'Arcy Cain wrote:
> I thought I was done with this crap once I moved to 3.x but some 
> Winblows machines are still sending what some circles call "Extended 
> ASCII".  I have a file that I am trying to read and it is barfing on 
> some characters.  For example:
> 
>    due to the Qu\xe9bec government
> 
> Obviously should be "due to the Qu?bec government".  I can't figure out 
> what that encoding is or if it is anything that can even be understood 
> outside of M$.  I have tried ascii, cp437, cp858, cp1140, cp1250, 
> latin-1, utf8 and others.  None of them recognize that character.  Can 
> someone tell me what encoding includes that character please.

It's latin-1 (or possibly cp1252 or something else depending on other
characters), your problem is elsewhere.

> Here is the failing code:
> 
> with open(sys.argv[1], encoding="latin-1") as fp:
>    for ln in fp:
>      print(ln)
> 
> Traceback (most recent call last):
>    File "./load_iff", line 11, in <module>
>      print(ln)
> UnicodeEncodeError: 'ascii' codec can't encode character '\xe9' in 
> position 132: ordinal not in range(128)

Note that this is an encode error - it's converting *from* unicode *to*
bytes, for the print statement.
 
> I don't understand why the error says "ascii" when I told it to use 
> "latin-1".

You set the encoding for the file, not the output. The problem is in
your print statement, and the fact that you probably have your locale
set to "C" or not set up at all instead of e.g. "en_CA.UTF-8".


From jon+usenet at unequivocal.eu  Fri Jan 13 17:43:24 2017
From: jon+usenet at unequivocal.eu (Jon Ribbens)
Date: Fri, 13 Jan 2017 22:43:24 -0000 (UTC)
Subject: Extended ASCII
References: <20aa3bc3-b26d-aa3d-2265-8e3c8d7bdf65@VybeNetworks.com>
 <mailman.10.1484346612.22298.python-list@python.org>
Message-ID: <slrno7im3c.2ca.jon+usenet@sable.unequivocal.eu>

On 2017-01-13, D'Arcy Cain <darcy at VybeNetworks.com> wrote:
> I thought I was done with this crap once I moved to 3.x but some 
> Winblows machines are still sending what some circles call "Extended 
> ASCII".  I have a file that I am trying to read and it is barfing on 
> some characters.  For example:
>
>    due to the Qu\xe9bec government
>
> Obviously should be "due to the Qu?bec government".  I can't figure out 
> what that encoding is or if it is anything that can even be understood 
> outside of M$.

$ cat decode.py
#!/usr/bin/env python3

CODECS = (
    "ascii", "big5", "big5hkscs", "cp037", "cp273", "cp424", "cp437", "cp500",
    "cp720", "cp737", "cp775", "cp850", "cp852", "cp855", "cp856", "cp857",
    "cp858", "cp860", "cp861", "cp862", "cp863", "cp864", "cp865", "cp866",
    "cp869", "cp874", "cp875", "cp932", "cp949", "cp950", "cp1006", "cp1026",
    "cp1125", "cp1140", "cp1250", "cp1251", "cp1252", "cp1253", "cp1254",
    "cp1255", "cp1256", "cp1257", "cp1258", "cp65001", "euc_jp",
    "euc_jis_2004", "euc_jisx0213", "euc_kr", "gb2312", "gbk", "gb18030", "hz",
    "iso2022_jp", "iso2022_jp_1", "iso2022_jp_2", "iso2022_jp_2004",
    "iso2022_jp_3", "iso2022_jp_ext", "iso2022_kr", "latin_1", "iso8859_2",
    "iso8859_3", "iso8859_4", "iso8859_5", "iso8859_6", "iso8859_7",
    "iso8859_8", "iso8859_9", "iso8859_10", "iso8859_11", "iso8859_13",
    "iso8859_14", "iso8859_15", "iso8859_16", "johab", "koi8_r", "koi8_t",
    "koi8_u", "kz1048", "mac_cyrillic", "mac_greek", "mac_iceland",
    "mac_latin2", "mac_roman", "mac_turkish", "ptcp154", "shift_jis",
    "shift_jis_2004", "shift_jisx0213", "utf_32", "utf_32_be", "utf_32_le",
    "utf_16", "utf_16_be", "utf_16_le", "utf_7", "utf_8", "utf_8_sig",
)

for encoding in CODECS:
    try:
        if b"Qu\xe9bec".decode(encoding) == "Qu?bec":
            print(encoding)
    except (UnicodeError, LookupError):
        pass

$ ./decode.py 
cp1250
cp1252
cp1254
cp1256
cp1257
cp1258
latin_1
iso8859_2
iso8859_3
iso8859_4
iso8859_9
iso8859_10
iso8859_13
iso8859_14
iso8859_15
iso8859_16


From grant.b.edwards at gmail.com  Fri Jan 13 17:44:09 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Fri, 13 Jan 2017 22:44:09 +0000 (UTC)
Subject: Extended ASCII
References: <20aa3bc3-b26d-aa3d-2265-8e3c8d7bdf65@VybeNetworks.com>
Message-ID: <o5bl7p$n2j$1@blaine.gmane.org>

On 2017-01-13, D'Arcy Cain <darcy at VybeNetworks.com> wrote:

> Here is the failing code:
>
> with open(sys.argv[1], encoding="latin-1") as fp:
>    for ln in fp:
>      print(ln)
>
> Traceback (most recent call last):
>    File "./load_iff", line 11, in <module>
>      print(ln)
> UnicodeEncodeError: 'ascii' codec can't encode character '\xe9' in 
> position 132: ordinal not in range(128)
>
> I don't understand why the error says "ascii" when I told it to use 
> "latin-1".

That can't be the failing code, since it's failing at line 11, and
that's only 5 lines. It helps if we can tell which line generated the
error.  ;)

I'm _guessing_ that line 11 is the print(), and it's barfing because
stdout is using ascii encoding, and there's no way to encode that
character in ascii so that it can be printed to an ascii output
stream.

-- 
Grant Edwards               grant.b.edwards        Yow! Everybody gets free
                                  at               BORSCHT!
                              gmail.com            



From python at lucidity.plus.com  Fri Jan 13 18:32:51 2017
From: python at lucidity.plus.com (Erik)
Date: Fri, 13 Jan 2017 23:32:51 +0000
Subject: How can I make a sentinel value NOT be initialized in a
 class/method - OOP?
In-Reply-To: <c49823f1-3d05-4101-a766-4ac5bca034f4@googlegroups.com>
References: <c49823f1-3d05-4101-a766-4ac5bca034f4@googlegroups.com>
Message-ID: <401cc9ce-824f-6cc5-c92e-c397430d11d4@lucidity.plus.com>

Hi,

On 13/01/17 22:26, daviddschool at gmail.com wrote:
> The issue I am having is that when i enter the sentinel value of QUIT, it gets initialized as the name and printed out.  How can I get around this?

If I understand the question correctly (which looks like it's just a 
re-worded homework question (*)), you need to look at the 'if' statement:

https://docs.python.org/3/tutorial/controlflow.html#if-statements

E.

(*) If it is a homework question, you'd look better on the list to state 
it as such, and post some code that at least tries to answer the 
question before you're likely to get a useful response. However, as you 
have indicated a specific problem, I'll assume you have actually written 
some code.


From oliver.schoenborn at gmail.com  Fri Jan 13 18:38:28 2017
From: oliver.schoenborn at gmail.com (oliver)
Date: Fri, 13 Jan 2017 23:38:28 +0000
Subject: Announcement: TLSv1.2 will become mandatory in the future for
 Python.org Sites
In-Reply-To: <CAMb+DaVjzUWCb4CaA7c+jUk34UAi_wayYL7jMmiAO3hSodJTFw@mail.gmail.com>
References: <1B1B29CD-AA4E-47C0-89A8-2748D5A14FC3@python.org>
 <CAMb+DaVjzUWCb4CaA7c+jUk34UAi_wayYL7jMmiAO3hSodJTFw@mail.gmail.com>
Message-ID: <CAMb+DaXMq=Ri+HVTRu1eZ=5jBMvfX0LbxoDDs4Rs8t3-KLmcKg@mail.gmail.com>

When I run this per email from my work laptop,

python3 -c "import urllib.request,json;
print(json.loads(urllib.request.urlopen('
https://www.howsmyssl.com/a/check').read())['tls_version'])"

I get the following traceback:

C:\...>python -c "import urllib.request,json;
print(json.loads(urllib.request.url
w.howsmyssl.com/a/check').read())['tls_version'])"
Traceback (most recent call last):
File "c:\Python35\lib\urllib\request.py", line 1254, in do_open
h.request(req.get_method(), req.selector, req.data, headers)
File "c:\Python35\lib\http\client.py", line 1106, in request
self._send_request(method, url, body, headers)
File "c:\Python35\lib\http\client.py", line 1151, in _send_request
self.endheaders(body)
File "c:\Python35\lib\http\client.py", line 1102, in endheaders
self._send_output(message_body)
File "c:\Python35\lib\http\client.py", line 934, in _send_output
self.send(msg)
File "c:\Python35\lib\http\client.py", line 877, in send
self.connect()
File "c:\Python35\lib\http\client.py", line 1260, in connect
server_hostname=server_hostname)
File "c:\Python35\lib\ssl.py", line 377, in wrap_socket
_context=self)
File "c:\Python35\lib\ssl.py", line 752, in __init__
self.do_handshake()
File "c:\Python35\lib\ssl.py", line 988, in do_handshake
self._sslobj.do_handshake()
File "c:\Python35\lib\ssl.py", line 633, in do_handshake
self._sslobj.do_handshake()
ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed
(_ssl.c:645)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "<string>", line 1, in <module>
File "c:\Python35\lib\urllib\request.py", line 163, in urlopen
return opener.open(url, data, timeout)
File "c:\Python35\lib\urllib\request.py", line 466, in open
response = self._open(req, data)
File "c:\Python35\lib\urllib\request.py", line 484, in _open
'_open', req)
File "c:\Python35\lib\urllib\request.py", line 444, in _call_chain
result = func(*args)
File "c:\Python35\lib\urllib\request.py", line 1297, in https_open
context=self._context, check_hostname=self._check_hostname)
File "c:\Python35\lib\urllib\request.py", line 1256, in do_open
raise URLError(err)
urllib.error.URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED]
certificate verify failed (_ssl.c:645)>

Anyone know how to deal with that? When using pip, I get same error, unless
I add "--trusted-host pypi.python.org":

C:\...>pip install nose
Collecting nose
Could not fetch URL https://pypi.python.org/simple/nose/: There was a
problem confirming the ssl certificate: [SSL: CERTIF
LED] certificate verify failed (_ssl.c:645) - skipping
Could not find a version that satisfies the requirement nose (from
versions: )
No matching distribution found for nose

C:\...>pip install nose --trusted-host pypi.python.org
Collecting nose
Downloading nose-1.3.7-py3-none-any.whl (154kB)
100% |################################| 163kB 386kB/s
Installing collected packages: nose
Successfully installed nose-1.3.7


-- 
Oliver
-- 
Oliver
My StackOverflow contributions
My CodeProject articles
My Github projects
My SourceForget.net projects


From ian.g.kelly at gmail.com  Fri Jan 13 18:52:55 2017
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 13 Jan 2017 16:52:55 -0700
Subject: How can I make a sentinel value NOT be initialized in a
 class/method - OOP?
In-Reply-To: <c49823f1-3d05-4101-a766-4ac5bca034f4@googlegroups.com>
References: <c49823f1-3d05-4101-a766-4ac5bca034f4@googlegroups.com>
Message-ID: <CALwzidkAaB_kEX1z_C-9EDY+OxExWhCw7wgH-S5VS6ZAtby+_Q@mail.gmail.com>

On Jan 13, 2017 3:33 PM, <daviddschool at gmail.com> wrote:


The issue I am having is that when i enter the sentinel value of QUIT, it
gets initialized as the name and printed out.  How can I get around this?
I hope this makes sense.


Hard to say for certain without seeing your code, but the most likely cause
of this is that the input string contains a trailing newline that causes it
to differ from the sentinel value you're comparing it to. Consider using
the rstrip string method to remove any trailing whitespace.


From hba008 at aol.com  Fri Jan 13 19:02:53 2017
From: hba008 at aol.com (=?utf-8?B?aGJhMDA4QGFvbC5jb20=?=)
Date: Sat, 14 Jan 2017 00:02:53 GMT
Subject: Can not run the  Python software
Message-ID: <000f4242.04d2cee60ab85b00@aol.com>







    I have been added to the mailing list per your instructions. Please, have someone address the problem below....Thanks
Sent from my Sprint Phone.



------ Original message------From: Date: Thu, Jan 5, 2017 10:13 PMTo: python-list at python.org;Subject:Can not run the  Python software
Hi,?Just downloaded Python 3.6.0 2016-12-23 and PyCharm. Tried to run the "Hello World" program and got the following message:"Process finished with exit code 1073741515 (0xC0000135)" I am using Windows 8.1 on an HP ENVY Touchsmart Notebook (64-bit OS, x64-based processor).Help Needed....Thanks,Bernard

From darcy at vex.net  Fri Jan 13 19:30:58 2017
From: darcy at vex.net (D'Arcy Cain)
Date: Fri, 13 Jan 2017 19:30:58 -0500
Subject: Extended ASCII [solved]
In-Reply-To: <o5bl7p$n2j$1@blaine.gmane.org>
References: <20aa3bc3-b26d-aa3d-2265-8e3c8d7bdf65@VybeNetworks.com>
 <o5bl7p$n2j$1@blaine.gmane.org>
Message-ID: <a8fa35e2-14b1-8060-277a-cc1ad3c96f1f@vex.net>

On 2017-01-13 05:44 PM, Grant Edwards wrote:
> On 2017-01-13, D'Arcy Cain <darcy at VybeNetworks.com> wrote:
>
>> Here is the failing code:
>>
>> with open(sys.argv[1], encoding="latin-1") as fp:
>>    for ln in fp:
>>      print(ln)
>>
>> Traceback (most recent call last):
>>    File "./load_iff", line 11, in <module>
>>      print(ln)
>> UnicodeEncodeError: 'ascii' codec can't encode character '\xe9' in
>> position 132: ordinal not in range(128)
>>
>> I don't understand why the error says "ascii" when I told it to use
>> "latin-1".
>
> That can't be the failing code, since it's failing at line 11, and
> that's only 5 lines. It helps if we can tell which line generated the
> error.  ;)

I didn't think that the part leading up to it was relevant.  Here it is.

#! /usr/bin/python

import sys, os

if len(sys.argv) < 2:
     print("No file named", file=sys.stderr)
     sys.exit(1)

> I'm _guessing_ that line 11 is the print(), and it's barfing because

Of course.  That's why the error is listed right below it.

> stdout is using ascii encoding, and there's no way to encode that
> character in ascii so that it can be printed to an ascii output
> stream.

Thank you!  I know all about that but for some reason I did not have 
PYTHONIOENCODING=utf8 set on that particular machine.  I have it set on 
every other machine I work on an never thought to check.  My Unicode 
universe is all right again.

Cheers.

-- 
D'Arcy J.M. Cain
System Administrator, Vex.Net
http://www.Vex.Net/ IM:darcy at Vex.Net
VoIP: sip:darcy at Vex.Net


From sohcahtoa82 at gmail.com  Fri Jan 13 20:02:30 2017
From: sohcahtoa82 at gmail.com (sohcahtoa82 at gmail.com)
Date: Fri, 13 Jan 2017 17:02:30 -0800 (PST)
Subject: How can I make a sentinel value NOT be initialized in a
 class/method - OOP?
In-Reply-To: <c49823f1-3d05-4101-a766-4ac5bca034f4@googlegroups.com>
References: <c49823f1-3d05-4101-a766-4ac5bca034f4@googlegroups.com>
Message-ID: <9e40483f-59e4-4e7a-a038-552f941e6927@googlegroups.com>

On Friday, January 13, 2017 at 2:27:04 PM UTC-8, David D wrote:
> I am testing out some basic Object Oriented Programming in Python.  The basics: 
> 
> -User enters a name 
> -While loop with a sentinel value of "quit" will continue entering names until the sentinel value is reached 
> -The object is created with the inputted value (NAME and until a sentinel value is entered) 
> -the object is then printed out using the constructor __str__ 
> 
> In my solution ( I am saying this because someone might have a work around that doesn't include the following below) 
> -I want to use __init__ 
> -I want to use __str__ 
> -I want to use a while loop with a sentinel value 
> 
> EXPLANATION: 
> I want to have the user enter in their NAME using a while loop, with "quit" being the sentinel value that breaks the loop.  Once the name is entered, an object is created and it is passed into a constructor def __ini__ (self, name) and then I have them return a string value using __str__ for the name entered. 
> The issue I am having is that when i enter the sentinel value of QUIT, it gets initialized as the name and printed out.  How can I get around this?  I hope this makes sense.

It would help if you posted your code to see what you're doing.

Also, is the sentinel value supposed to be "quit" or "QUIT"?  If you're only checking for "quit", but you type "QUIT", it isn't going to work.  Programs execute exactly as you write them, and "quit" is not the same as "QUIT".


From hba008 at aol.com  Fri Jan 13 20:34:23 2017
From: hba008 at aol.com (hba008 at aol.com)
Date: Fri, 13 Jan 2017 20:34:23 -0500
Subject: Can not run the  Python software
In-Reply-To: <000f4242.04d2cee60ab85b00@aol.com>
References: <000f4242.04d2cee60ab85b00@aol.com>
Message-ID: <1599a9c7b49-1232-d4f@webstg-m06.mail.aol.com>


 
 
 
-----Original Message-----
From: hba008 <hba008 at aol.com>
To: hba008 <hba008 at aol.com>; python-list <python-list at python.org>
Sent: Fri, Jan 13, 2017 7:02 pm
Subject: Re: Can not run the  Python software


    
I have been added to the mailing list per your instructions. Please, have someone address the problem below....Thanks


Sent from my Sprint Phone.




------ Original message------
From: 
Date: Thu, Jan 5, 2017 10:13 PM
To: python-list at python.org;
Subject:Can not run the  Python software



Hi,
 
Just downloaded Python 3.6.0 2016-12-23 and PyCharm. Tried to run the "Hello World" program and got the following message:
"Process finished with exit code 1073741515 (0xC0000135)" 
I am using Windows 8.1 on an HP ENVY Touchsmart Notebook (64-bit OS, x64-based processor).
Help Needed....
Thanks,
Bernard




From torriem at gmail.com  Fri Jan 13 22:01:21 2017
From: torriem at gmail.com (Michael Torrie)
Date: Fri, 13 Jan 2017 20:01:21 -0700
Subject: Can not run the Python software
In-Reply-To: <1599a9c7b49-1232-d4f@webstg-m06.mail.aol.com>
References: <000f4242.04d2cee60ab85b00@aol.com>
 <1599a9c7b49-1232-d4f@webstg-m06.mail.aol.com>
Message-ID: <0a2d8b37-0c5e-b349-6d6c-0bcf05dcdfe6@gmail.com>

On 01/13/2017 06:34 PM, Bernard via Python-list wrote:
> Hi,
>  
> Just downloaded Python 3.6.0 2016-12-23 and PyCharm. Tried to run the "Hello World" program and got the following message:
> "Process finished with exit code 1073741515 (0xC0000135)" 
> I am using Windows 8.1 on an HP ENVY Touchsmart Notebook (64-bit OS, x64-based processor).
> Help Needed....

Unfortunately there's not a lot of information there to go on, which is
why you haven't got any replies yet.  What was the python program you
tried to run? How did you run it?  The error message you quote does not
appear to be a Python error message, so I'm not sure where it is coming
from.  It's possible the python interpreter itself crashed, which is
unusual, especially for a simple program.  Can you post the entire
python program you were trying to run?

Also can you try a simple program of your own such as this as a sanity
check?

print ("Hello, World.")




From brettsalyer at gmail.com  Fri Jan 13 22:16:07 2017
From: brettsalyer at gmail.com (Brett Salyer)
Date: Fri, 13 Jan 2017 19:16:07 -0800 (PST)
Subject: Software to Control RGB Strips
In-Reply-To: <739c31a6-bf54-41c9-b5c8-050bbe174ac9@googlegroups.com>
References: <739c31a6-bf54-41c9-b5c8-050bbe174ac9@googlegroups.com>
Message-ID: <1eae2e6a-3f84-4820-b648-58d23ca39125@googlegroups.com>

On Friday, January 13, 2017 at 1:07:40 PM UTC-5, Brett Salyer wrote:
> Hey all,
> 
> I was debating on getting some RGB light strips for my room. I noticed, from this tutorial:
> 
> http://popoklopsi.github.io/RaspberryPi-LedStrip/#!/ws2812
> 
> 
> there is a  WS2812x library to run commands that control the RGB strip. Well, I wanted to, instead of running commands through a terminal, create a GUI using python, then exploit the library I mentioned above to create a piece of software that controls my lighting from my Raspberry Pi.
> 
> I was going to use Tkinter to create the GUI. 
> 
> Now, I'm a pretty beginner programmer, having only taken a C++ course and the Java course I'm in now.
> 
> Do I just need to download the WS2812x library, and, then, access that library as I would, say, a header file in C++? In Pythons syntax, of course.
> 
> Anything to get me pointed in the right direction would be greatly appreciated! Thanks!

Thanks a lot, man!


From jcasale at activenetwerx.com  Fri Jan 13 22:32:26 2017
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Sat, 14 Jan 2017 03:32:26 +0000
Subject: Can not run the  Python software
In-Reply-To: <1599a9c7b49-1232-d4f@webstg-m06.mail.aol.com>
References: <000f4242.04d2cee60ab85b00@aol.com>
 <1599a9c7b49-1232-d4f@webstg-m06.mail.aol.com>
Message-ID: <c47f15475d7b474796419e851f6dfa79@activenetwerx.com>

> Just downloaded Python 3.6.0 2016-12-23 and PyCharm. Tried to run the "Hello World" program and got the following message:
> "Process finished with exit code 1073741515 (0xC0000135)" 
> I am using Windows 8.1 on an HP ENVY Touchsmart Notebook (64-bit OS, x64-based processor).

If you track the error, it indicates a file was not found, bets are
you don't have the needed runtime installed for Python to run.

Nothing else PyCharm can do here, it tries to start Python and
fails.

If memory serves me, you need the Visual C++ Redistributable
for Visual Studio 2015...

jlc


From torriem at gmail.com  Fri Jan 13 23:08:04 2017
From: torriem at gmail.com (Michael Torrie)
Date: Fri, 13 Jan 2017 21:08:04 -0700
Subject: Can not run the Python software
In-Reply-To: <c47f15475d7b474796419e851f6dfa79@activenetwerx.com>
References: <000f4242.04d2cee60ab85b00@aol.com>
 <1599a9c7b49-1232-d4f@webstg-m06.mail.aol.com>
 <c47f15475d7b474796419e851f6dfa79@activenetwerx.com>
Message-ID: <4a5c7ae0-b09a-9063-f521-3318c71d769c@gmail.com>

On 01/13/2017 08:32 PM, Joseph L. Casale wrote:
>> Just downloaded Python 3.6.0 2016-12-23 and PyCharm. Tried to run the "Hello World" program and got the following message:
>> "Process finished with exit code 1073741515 (0xC0000135)" 
>> I am using Windows 8.1 on an HP ENVY Touchsmart Notebook (64-bit OS, x64-based processor).
> 
> If you track the error, it indicates a file was not found, bets are
> you don't have the needed runtime installed for Python to run.
> 
> Nothing else PyCharm can do here, it tries to start Python and
> fails.
> 
> If memory serves me, you need the Visual C++ Redistributable
> for Visual Studio 2015...

And this is coming up a lot.  This is something that should already be
on all supported versions of Windows if Windows updates are done, right?
 It's probably in the FAQ on python.org, and I know this is really a
user problem (not installing updates), but maybe it's time that the
Python installer bundles the redistributable installer and installs it
if necessary during Python's install.  We get queries on the list almost
weekly from Windows users.


From hba008 at aol.com  Fri Jan 13 23:20:30 2017
From: hba008 at aol.com (hba008 at aol.com)
Date: Fri, 13 Jan 2017 23:20:30 -0500
Subject: Can not run the Python software
In-Reply-To: <4a5c7ae0-b09a-9063-f521-3318c71d769c@gmail.com>
Message-ID: <1599b34906a-29af-209a@webstg-m09.mail.aol.com>


Thanks for the info..
 
 
 
-----Original Message-----
From: Michael Torrie <torriem at gmail.com>
To: python-list <python-list at python.org>
Sent: Fri, Jan 13, 2017 11:08 pm
Subject: Re: Can not run the Python software

On 01/13/2017 08:32 PM, Joseph L. Casale wrote:
>> Just downloaded Python 3.6.0 2016-12-23 and PyCharm. Tried to run the "Hello World" program and got the following message:
>> "Process finished with exit code 1073741515 (0xC0000135)" 
>> I am using Windows 8.1 on an HP ENVY Touchsmart Notebook (64-bit OS, x64-based processor).
> 
> If you track the error, it indicates a file was not found, bets are
> you don't have the needed runtime installed for Python to run.
> 
> Nothing else PyCharm can do here, it tries to start Python and
> fails.
> 
> If memory serves me, you need the Visual C++ Redistributable
> for Visual Studio 2015...

And this is coming up a lot.  This is something that should already be
on all supported versions of Windows if Windows updates are done, right?
 It's probably in the FAQ on python.org, and I know this is really a
user problem (not installing updates), but maybe it's time that the
Python installer bundles the redistributable installer and installs it
if necessary during Python's install.  We get queries on the list almost
weekly from Windows users.
-- 
https://mail.python.org/mailman/listinfo/python-list



From jcasale at activenetwerx.com  Fri Jan 13 23:22:43 2017
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Sat, 14 Jan 2017 04:22:43 +0000
Subject: Can not run the Python software
In-Reply-To: <4a5c7ae0-b09a-9063-f521-3318c71d769c@gmail.com>
References: <000f4242.04d2cee60ab85b00@aol.com>
 <1599a9c7b49-1232-d4f@webstg-m06.mail.aol.com>
 <c47f15475d7b474796419e851f6dfa79@activenetwerx.com>
 <4a5c7ae0-b09a-9063-f521-3318c71d769c@gmail.com>
Message-ID: <97dbd7d47c2445a381ecb3a857fb1a95@activenetwerx.com>

> And this is coming up a lot.  This is something that should already be
> on all supported versions of Windows if Windows updates are done, right?

No, it's not an update. You install the runtime *if* you need it.

 > but maybe it's time that the
> Python installer bundles the redistributable installer and installs it
> if necessary during Python's install.

That's exactly how most other software does work and wix for example
even has support for it...

http://wixtoolset.org/documentation/manual/v3/howtos/redistributables_and_install_checks/




From shahsn11 at gmail.com  Fri Jan 13 23:42:47 2017
From: shahsn11 at gmail.com (shahsn11 at gmail.com)
Date: Fri, 13 Jan 2017 20:42:47 -0800 (PST)
Subject: Python Web Scrapping : Within href readonly those value that have
 href in it
Message-ID: <d611e6b8-5653-436f-90f8-0a868e160e22@googlegroups.com>

I am trying to scrape a webpage just for learning. In that webpage there are multiple "a" tags. consider the below code

<a href='\abc\def\jkl'> Something </a>

<a href ='http:\\www.google.com'> Something</a>


Now i want to read only those href in which there is http. My Current code is

for link in soup.find_all("a"):
    print link.get("href")

i would like to change it to read only http links.


From dieter at handshake.de  Sat Jan 14 03:38:09 2017
From: dieter at handshake.de (dieter)
Date: Sat, 14 Jan 2017 09:38:09 +0100
Subject: timers in threaded application
References: <CANc-5UxNU9tiCVM0cSKZH-wm68TSB-tO+3Xmy=__cA-oyU4o=Q@mail.gmail.com>
 <87lguf9uu0.fsf@handshake.de>
 <CANc-5Uz44rTNRe_08F=WryGWZycnZz344daP+nWetGjRmmekTw@mail.gmail.com>
Message-ID: <87o9zahw9a.fsf@handshake.de>

Skip Montanaro <skip.montanaro at gmail.com> writes:

> On Fri, Jan 13, 2017 at 3:23 AM, dieter <dieter at handshake.de> wrote:
>
>> If what you want to timeout are not I/O operations, you can have a
>> look at "threading.Timer". It uses a separate thread, lets it wait
>> a specified time and then starts a specified function, unless
>> "cancel"ed.
>>
>
> Ooh, hadn't considered that. That would seem to do the trick. I assume the
> function to be executed will be run in the timer's thread, so will have to
> suitably lock any shared data.

Yes.



From dieter at handshake.de  Sat Jan 14 03:43:45 2017
From: dieter at handshake.de (dieter)
Date: Sat, 14 Jan 2017 09:43:45 +0100
Subject: Running Virtualenv with a custom distlib?
References: <2bc1125c-eb70-49bc-bd90-ebeaa9741258@googlegroups.com>
Message-ID: <87k29yhvzy.fsf@handshake.de>

haraldnordgren at gmail.com writes:

> I want to do some development on `distlib`, and in the process run the code via `virtualenv` which has distlib as a dependency.
>
> That is, not run the process inside a virtualenv, but run virtualenv's code using a custom dependency. What are the steps I need to go through to achieve this?

I would try to run "virtualenv" in a virtual environment with a "distlib"
seemingly to fulfill the "virtualenv" requirements but in fact be under
your control (e.g. set up via "python setup.py develop").

I do not know whether the virtual environment mentioned above can
be set up via "virtualenv" itself (that would be the easiest thing).
If not, I would install "python" from source and tweak its "site-packages"
as necessary.



From __peter__ at web.de  Sat Jan 14 03:44:33 2017
From: __peter__ at web.de (Peter Otten)
Date: Sat, 14 Jan 2017 09:44:33 +0100
Subject: Python Web Scrapping : Within href readonly those value that have
 href in it
References: <d611e6b8-5653-436f-90f8-0a868e160e22@googlegroups.com>
Message-ID: <o5codd$cc5$1@blaine.gmane.org>

shahsn11 at gmail.com wrote:

> I am trying to scrape a webpage just for learning. In that webpage there
> are multiple "a" tags. consider the below code
> 
> <a href='\abc\def\jkl'> Something </a>
> 
> <a href ='http:\\www.google.com'> Something</a>

These are probaly all forward slashes.

> Now i want to read only those href in which there is http. My Current code
> is
> 
> for link in soup.find_all("a"):
>     print link.get("href")
> 
> i would like to change it to read only http links.

You mean href values that start with "http://"?
While you can do that with a callback

def check_scheme(href):
    return href is not None and href.startswith("http://")

for a in soup.find_all("a", href=check_scheme):
    print(a["href"])

or a regular expression

import re

for a in soup.find_all("a", href=re.compile("^http://")):
    print(a["href"])

why not keep things simple and check before printing? Like

for a in soup.find_all("a"):
    href = a.get("href", "") # empty string if href is missing
    if href.startswith("http://"):
        print(href)




From dieter at handshake.de  Sat Jan 14 04:03:26 2017
From: dieter at handshake.de (dieter)
Date: Sat, 14 Jan 2017 10:03:26 +0100
Subject: Announcement: TLSv1.2 will become mandatory in the future for
 Python.org Sites
References: <1B1B29CD-AA4E-47C0-89A8-2748D5A14FC3@python.org>
 <CAMb+DaVjzUWCb4CaA7c+jUk34UAi_wayYL7jMmiAO3hSodJTFw@mail.gmail.com>
 <CAMb+DaXMq=Ri+HVTRu1eZ=5jBMvfX0LbxoDDs4Rs8t3-KLmcKg@mail.gmail.com>
Message-ID: <87fukmhv35.fsf@handshake.de>

oliver <oliver.schoenborn at gmail.com> writes:

> When I run this per email from my work laptop,
>
> python3 -c "import urllib.request,json;
> print(json.loads(urllib.request.urlopen('
> https://www.howsmyssl.com/a/check').read())['tls_version'])"
>
> I get the following traceback:
> ...
> File "c:\Python35\lib\ssl.py", line 633, in do_handshake
> self._sslobj.do_handshake()
> ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed
> (_ssl.c:645)

I guess (!) that somehow the well known trusted CA (= "Certificate authority")
certificates are incomplete on your machine.

Certificate verification works as follows:
a certificate is always signed by a certificate authority ("CA");
for a certificate to be trusted, the signing CA must be trusted.
There may be several trust steps but finally, there must be
some "CA" that you are trusting "without further proof".
The certificates of those "CA"s are somewhere stored on your machine.

Apparently, the "https" servers you have problems with
are using a CA which is not declared trusted on your machine
(by installing the appropriate certificate at the correct place).



From saxri89 at gmail.com  Sat Jan 14 06:18:33 2017
From: saxri89 at gmail.com (Xristos Xristoou)
Date: Sat, 14 Jan 2017 03:18:33 -0800 (PST)
Subject: geopandas bug ?
Message-ID: <2bffcdb3-066a-4f91-b00b-e390dd03c103@googlegroups.com>

i want  to create a simple spatial joing using geopandas but i thing so geopandas has bug ?



geopandas code :

from geopandas import gpd
import geopandas
points = geopandas.GeoDataFrame.from_file('points.shp') # or geojson etc
polys = geopandas.GeoDataFrame.from_file('polygons.shp')
pointInPoly = gpd.sjoin(points, polys, how='left',op='within')

error :

Traceback (most recent call last):
  File "/home/sarantis/testshapely/sumpointsinsidepolygon/testgeo.py", line 7, in <module>
    pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
  File "/usr/local/lib/python2.7/dist-packages/geopandas/tools/sjoin.py", line 57, in sjoin
    r_idx = np.concatenate(idxmatch.values)
ValueError: need at least one array to concatenate

and if i change the imports with the some code :

import geopandas
import pandas as pd
import geopandas as gpd
from geopandas import GeoDataFrame, read_file
from geopandas.tools import sjoin
from shapely.geometry import Point, mapping,shape
import pandas as gpd

i take that error :

    pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
AttributeError: 'module' object has no attribute 'sjoin'


any idea why ?


From saxri89 at gmail.com  Sat Jan 14 06:20:24 2017
From: saxri89 at gmail.com (Xristos Xristoou)
Date: Sat, 14 Jan 2017 03:20:24 -0800 (PST)
Subject: geopandas bug ?
Message-ID: <d3ee516b-d229-4d91-8ba1-f96b5eefc5a6@googlegroups.com>

i want  to create a simple spatial joing using geopandas but i thing so geopandas has bug ?



geopandas code :

from geopandas import gpd
import geopandas
points = geopandas.GeoDataFrame.from_file('points.shp') # or geojson etc
polys = geopandas.GeoDataFrame.from_file('polygons.shp')
pointInPoly = gpd.sjoin(points, polys, how='left',op='within')

error :

Traceback (most recent call last):
  File "/home/username/testshapely/sumpointsinsidepolygon/testgeo.py", line 7, in <module>
    pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
  File "/usr/local/lib/python2.7/dist-packages/geopandas/tools/sjoin.py", line 57, in sjoin
    r_idx = np.concatenate(idxmatch.values)
ValueError: need at least one array to concatenate

and if i change the imports with the some code :

import geopandas
import pandas as pd
import geopandas as gpd
from geopandas import GeoDataFrame, read_file
from geopandas.tools import sjoin
from shapely.geometry import Point, mapping,shape
import pandas as gpd

i take that error :

    pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
AttributeError: 'module' object has no attribute 'sjoin'


any idea why ?


From __peter__ at web.de  Sat Jan 14 08:42:23 2017
From: __peter__ at web.de (Peter Otten)
Date: Sat, 14 Jan 2017 14:42:23 +0100
Subject: geopandas bug ?
References: <2bffcdb3-066a-4f91-b00b-e390dd03c103@googlegroups.com>
Message-ID: <o5d9rr$l7q$1@blaine.gmane.org>

Xristos Xristoou wrote:

> i want  to create a simple spatial joing using geopandas but i thing so
> geopandas has bug ?

Have you tried the examples on <http://geopandas.org/mergingdata.html>?
Do they work? If yes, inspect your data, does it have the same format?

> geopandas code :
> 
> from geopandas import gpd
> import geopandas
> points = geopandas.GeoDataFrame.from_file('points.shp') # or geojson etc
> polys = geopandas.GeoDataFrame.from_file('polygons.shp')
> pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
> 
> error :
> 
> Traceback (most recent call last):
>   File "/home/sarantis/testshapely/sumpointsinsidepolygon/testgeo.py",
>   line 7, in <module>
>     pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
>   File "/usr/local/lib/python2.7/dist-packages/geopandas/tools/sjoin.py",
>   line 57, in sjoin
>     r_idx = np.concatenate(idxmatch.values)
> ValueError: need at least one array to concatenate
> 
> and if i change the imports with the some code :
> 
> import geopandas
> import pandas as pd
> import geopandas as gpd
> from geopandas import GeoDataFrame, read_file
> from geopandas.tools import sjoin
> from shapely.geometry import Point, mapping,shape
> import pandas as gpd
> 
> i take that error :
> 
>     pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
> AttributeError: 'module' object has no attribute 'sjoin'
> 
> 
> any idea why ?

My crystal ball says that either points or polys is empty ;)




From saxri89 at gmail.com  Sat Jan 14 09:06:15 2017
From: saxri89 at gmail.com (Xristos Xristoou)
Date: Sat, 14 Jan 2017 06:06:15 -0800 (PST)
Subject: geopandas bug ?
In-Reply-To: <mailman.4.1484401371.2442.python-list@python.org>
References: <2bffcdb3-066a-4f91-b00b-e390dd03c103@googlegroups.com>
 <o5d9rr$l7q$1@blaine.gmane.org>
 <mailman.4.1484401371.2442.python-list@python.org>
Message-ID: <aaacba13-a82d-4eb8-9265-502ef9a6824d@googlegroups.com>

?? ???????, 14 ?????????? 2017 - 3:43:10 ?.?. UTC+2, ? ??????? Peter Otten ??????:
> Xristos Xristoou wrote:
> 
> > i want  to create a simple spatial joing using geopandas but i thing so
> > geopandas has bug ?
> 
> Have you tried the examples on <http://geopandas.org/mergingdata.html>?
> Do they work? If yes, inspect your data, does it have the same format?
> 
> > geopandas code :
> > 
> > from geopandas import gpd
> > import geopandas
> > points = geopandas.GeoDataFrame.from_file('points.shp') # or geojson etc
> > polys = geopandas.GeoDataFrame.from_file('polygons.shp')
> > pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
> > 
> > error :
> > 
> > Traceback (most recent call last):
> >   File "/home/sarantis/testshapely/sumpointsinsidepolygon/testgeo.py",
> >   line 7, in <module>
> >     pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
> >   File "/usr/local/lib/python2.7/dist-packages/geopandas/tools/sjoin.py",
> >   line 57, in sjoin
> >     r_idx = np.concatenate(idxmatch.values)
> > ValueError: need at least one array to concatenate
> > 
> > and if i change the imports with the some code :
> > 
> > import geopandas
> > import pandas as pd
> > import geopandas as gpd
> > from geopandas import GeoDataFrame, read_file
> > from geopandas.tools import sjoin
> > from shapely.geometry import Point, mapping,shape
> > import pandas as gpd
> > 
> > i take that error :
> > 
> >     pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
> > AttributeError: 'module' object has no attribute 'sjoin'
> > 
> > 
> > any idea why ?
> 
> My crystal ball says that either points or polys is empty ;)

is not empty and yes i have two shapefiles from qgis.what is the error ?


From __peter__ at web.de  Sat Jan 14 09:30:05 2017
From: __peter__ at web.de (Peter Otten)
Date: Sat, 14 Jan 2017 15:30:05 +0100
Subject: geopandas bug ?
References: <2bffcdb3-066a-4f91-b00b-e390dd03c103@googlegroups.com>
 <o5d9rr$l7q$1@blaine.gmane.org>
 <mailman.4.1484401371.2442.python-list@python.org>
 <aaacba13-a82d-4eb8-9265-502ef9a6824d@googlegroups.com>
Message-ID: <o5dcl8$6rl$1@blaine.gmane.org>

Xristos Xristoou wrote:

> ?? ???????, 14 ?????????? 2017 - 3:43:10 ?.?. UTC+2, ? ??????? Peter Otten
> ??????:
>> Xristos Xristoou wrote:
>> 
>> > i want  to create a simple spatial joing using geopandas but i thing so
>> > geopandas has bug ?
>> 
>> Have you tried the examples on <http://geopandas.org/mergingdata.html>?
>> Do they work? If yes, inspect your data, does it have the same format?

Looks like you chose to ignore the hard part.
 
>> > geopandas code :
>> > 
>> > from geopandas import gpd
>> > import geopandas
>> > points = geopandas.GeoDataFrame.from_file('points.shp') # or geojson
>> > etc polys = geopandas.GeoDataFrame.from_file('polygons.shp')
>> > pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
>> > 
>> > error :
>> > 
>> > Traceback (most recent call last):
>> >   File "/home/sarantis/testshapely/sumpointsinsidepolygon/testgeo.py",
>> >   line 7, in <module>
>> >     pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
>> >   File
>> >   "/usr/local/lib/python2.7/dist-packages/geopandas/tools/sjoin.py",
>> >   line 57, in sjoin
>> >     r_idx = np.concatenate(idxmatch.values)
>> > ValueError: need at least one array to concatenate

>> > any idea why ?
>> 
>> My crystal ball says that either points or polys is empty ;)
> 
> is not empty and yes i have two shapefiles from qgis.

Can I download those files somewhere?

> what is the error ?

No idea. Without those files I cannot run your code.



From saxri89 at gmail.com  Sat Jan 14 09:37:08 2017
From: saxri89 at gmail.com (Xristos Xristoou)
Date: Sat, 14 Jan 2017 06:37:08 -0800 (PST)
Subject: geopandas bug ?
In-Reply-To: <mailman.5.1484404236.2442.python-list@python.org>
References: <2bffcdb3-066a-4f91-b00b-e390dd03c103@googlegroups.com>
 <o5d9rr$l7q$1@blaine.gmane.org>
 <mailman.4.1484401371.2442.python-list@python.org>
 <aaacba13-a82d-4eb8-9265-502ef9a6824d@googlegroups.com>
 <o5dcl8$6rl$1@blaine.gmane.org>
 <mailman.5.1484404236.2442.python-list@python.org>
Message-ID: <9a293ac7-d306-4c8b-9f7e-f5a0de377169@googlegroups.com>

?? ???????, 14 ?????????? 2017 - 4:30:48 ?.?. UTC+2, ? ??????? Peter Otten ??????:
> Xristos Xristoou wrote:
> 
> > ?? ???????, 14 ?????????? 2017 - 3:43:10 ?.?. UTC+2, ? ??????? Peter Otten
> > ??????:
> >> Xristos Xristoou wrote:
> >> 
> >> > i want  to create a simple spatial joing using geopandas but i thing so
> >> > geopandas has bug ?
> >> 
> >> Have you tried the examples on <http://geopandas.org/mergingdata.html>?
> >> Do they work? If yes, inspect your data, does it have the same format?
> 
> Looks like you chose to ignore the hard part.
>  
> >> > geopandas code :
> >> > 
> >> > from geopandas import gpd
> >> > import geopandas
> >> > points = geopandas.GeoDataFrame.from_file('points.shp') # or geojson
> >> > etc polys = geopandas.GeoDataFrame.from_file('polygons.shp')
> >> > pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
> >> > 
> >> > error :
> >> > 
> >> > Traceback (most recent call last):
> >> >   File "/home/sarantis/testshapely/sumpointsinsidepolygon/testgeo.py",
> >> >   line 7, in <module>
> >> >     pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
> >> >   File
> >> >   "/usr/local/lib/python2.7/dist-packages/geopandas/tools/sjoin.py",
> >> >   line 57, in sjoin
> >> >     r_idx = np.concatenate(idxmatch.values)
> >> > ValueError: need at least one array to concatenate
> 
> >> > any idea why ?
> >> 
> >> My crystal ball says that either points or polys is empty ;)
> > 
> > is not empty and yes i have two shapefiles from qgis.
> 
> Can I download those files somewhere?
> 
> > what is the error ?
> 
> No idea. Without those files I cannot run your code.

yes i sent you


From duncan at invalid.invalid  Sat Jan 14 09:38:29 2017
From: duncan at invalid.invalid (duncan smith)
Date: Sat, 14 Jan 2017 14:38:29 +0000
Subject: geopandas bug ?
In-Reply-To: <2bffcdb3-066a-4f91-b00b-e390dd03c103@googlegroups.com>
References: <2bffcdb3-066a-4f91-b00b-e390dd03c103@googlegroups.com>
Message-ID: <GJqeA.959$DF1.330@fx02.iad>

On 14/01/17 11:18, Xristos Xristoou wrote:
> i want  to create a simple spatial joing using geopandas but i thing so geopandas has bug ?
> 
> 
> 
> geopandas code :
> 
> from geopandas import gpd
> import geopandas
> points = geopandas.GeoDataFrame.from_file('points.shp') # or geojson etc
> polys = geopandas.GeoDataFrame.from_file('polygons.shp')
> pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
> 
> error :
> 
> Traceback (most recent call last):
>   File "/home/sarantis/testshapely/sumpointsinsidepolygon/testgeo.py", line 7, in <module>
>     pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
>   File "/usr/local/lib/python2.7/dist-packages/geopandas/tools/sjoin.py", line 57, in sjoin
>     r_idx = np.concatenate(idxmatch.values)
> ValueError: need at least one array to concatenate
> 
> and if i change the imports with the some code :
> 
> import geopandas
> import pandas as pd
> import geopandas as gpd
> from geopandas import GeoDataFrame, read_file
> from geopandas.tools import sjoin
> from shapely.geometry import Point, mapping,shape
> import pandas as gpd
> 
> i take that error :
> 
>     pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
> AttributeError: 'module' object has no attribute 'sjoin'
> 
> 
> any idea why ?
> 


import geopandas as gpd
import pandas as gpd

Does pandas have an attribute 'sjoin'?

Duncan


From saxri89 at gmail.com  Sat Jan 14 09:58:59 2017
From: saxri89 at gmail.com (Xristos Xristoou)
Date: Sat, 14 Jan 2017 06:58:59 -0800 (PST)
Subject: geopandas bug ?
In-Reply-To: <mailman.5.1484404236.2442.python-list@python.org>
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?? ???????, 14 ?????????? 2017 - 4:30:48 ?.?. UTC+2, ? ??????? Peter Otten ??????:
> Xristos Xristoou wrote:
> 
> > ?? ???????, 14 ?????????? 2017 - 3:43:10 ?.?. UTC+2, ? ??????? Peter Otten
> > ??????:
> >> Xristos Xristoou wrote:
> >> 
> >> > i want  to create a simple spatial joing using geopandas but i thing so
> >> > geopandas has bug ?
> >> 
> >> Have you tried the examples on <http://geopandas.org/mergingdata.html>?
> >> Do they work? If yes, inspect your data, does it have the same format?
> 
> Looks like you chose to ignore the hard part.
>  
> >> > geopandas code :
> >> > 
> >> > from geopandas import gpd
> >> > import geopandas
> >> > points = geopandas.GeoDataFrame.from_file('points.shp') # or geojson
> >> > etc polys = geopandas.GeoDataFrame.from_file('polygons.shp')
> >> > pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
> >> > 
> >> > error :
> >> > 
> >> > Traceback (most recent call last):
> >> >   File "/home/sarantis/testshapely/sumpointsinsidepolygon/testgeo.py",
> >> >   line 7, in <module>
> >> >     pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
> >> >   File
> >> >   "/usr/local/lib/python2.7/dist-packages/geopandas/tools/sjoin.py",
> >> >   line 57, in sjoin
> >> >     r_idx = np.concatenate(idxmatch.values)
> >> > ValueError: need at least one array to concatenate
> 
> >> > any idea why ?
> >> 
> >> My crystal ball says that either points or polys is empty ;)
> > 
> > is not empty and yes i have two shapefiles from qgis.
> 
> Can I download those files somewhere?
> 
> > what is the error ?
> 
> No idea. Without those files I cannot run your code.

https://www.dropbox.com/s/2693nfi248z0y9q/files.zip?dl=0 with the shapefiles


From saxri89 at gmail.com  Sat Jan 14 09:59:55 2017
From: saxri89 at gmail.com (Xristos Xristoou)
Date: Sat, 14 Jan 2017 06:59:55 -0800 (PST)
Subject: geopandas bug ?
In-Reply-To: <GJqeA.959$DF1.330@fx02.iad>
References: <2bffcdb3-066a-4f91-b00b-e390dd03c103@googlegroups.com>
 <GJqeA.959$DF1.330@fx02.iad>
Message-ID: <f36a02ed-774e-45a2-926e-76f13fd4288d@googlegroups.com>

?? ???????, 14 ?????????? 2017 - 4:38:39 ?.?. UTC+2, ? ??????? duncan smith ??????:
> On 14/01/17 11:18, Xristos Xristoou wrote:
> > i want  to create a simple spatial joing using geopandas but i thing so geopandas has bug ?
> > 
> > 
> > 
> > geopandas code :
> > 
> > from geopandas import gpd
> > import geopandas
> > points = geopandas.GeoDataFrame.from_file('points.shp') # or geojson etc
> > polys = geopandas.GeoDataFrame.from_file('polygons.shp')
> > pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
> > 
> > error :
> > 
> > Traceback (most recent call last):
> >   File "/home/sarantis/testshapely/sumpointsinsidepolygon/testgeo.py", line 7, in <module>
> >     pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
> >   File "/usr/local/lib/python2.7/dist-packages/geopandas/tools/sjoin.py", line 57, in sjoin
> >     r_idx = np.concatenate(idxmatch.values)
> > ValueError: need at least one array to concatenate
> > 
> > and if i change the imports with the some code :
> > 
> > import geopandas
> > import pandas as pd
> > import geopandas as gpd
> > from geopandas import GeoDataFrame, read_file
> > from geopandas.tools import sjoin
> > from shapely.geometry import Point, mapping,shape
> > import pandas as gpd
> > 
> > i take that error :
> > 
> >     pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
> > AttributeError: 'module' object has no attribute 'sjoin'
> > 
> > 
> > any idea why ?
> > 
> 
> 
> import geopandas as gpd
> import pandas as gpd
> 
> Does pandas have an attribute 'sjoin'?
> 
> Duncan

i dont know i follow detais i am newbie


From __peter__ at web.de  Sat Jan 14 11:00:41 2017
From: __peter__ at web.de (Peter Otten)
Date: Sat, 14 Jan 2017 17:00:41 +0100
Subject: geopandas bug ?
References: <2bffcdb3-066a-4f91-b00b-e390dd03c103@googlegroups.com>
 <o5d9rr$l7q$1@blaine.gmane.org>
 <mailman.4.1484401371.2442.python-list@python.org>
 <aaacba13-a82d-4eb8-9265-502ef9a6824d@googlegroups.com>
 <o5dcl8$6rl$1@blaine.gmane.org>
 <mailman.5.1484404236.2442.python-list@python.org>
 <bf010388-33e2-467d-88b9-c59fd6f9dbda@googlegroups.com>
Message-ID: <o5dhv4$9ov$1@blaine.gmane.org>

Xristos Xristoou wrote:

> ?? ???????, 14 ?????????? 2017 - 4:30:48 ?.?. UTC+2, ? ??????? Peter Otten
> ??????:
>> Xristos Xristoou wrote:
>> 
>> > ?? ???????, 14 ?????????? 2017 - 3:43:10 ?.?. UTC+2, ? ??????? Peter
>> > Otten ??????:
>> >> Xristos Xristoou wrote:
>> >> 
>> >> > i want  to create a simple spatial joing using geopandas but i thing
>> >> > so geopandas has bug ?
>> >> 
>> >> Have you tried the examples on
>> >> <http://geopandas.org/mergingdata.html>? Do they work? If yes, inspect
>> >> your data, does it have the same format?
>> 
>> Looks like you chose to ignore the hard part.
>>  
>> >> > geopandas code :
>> >> > 
>> >> > from geopandas import gpd
>> >> > import geopandas
>> >> > points = geopandas.GeoDataFrame.from_file('points.shp') # or geojson
>> >> > etc polys = geopandas.GeoDataFrame.from_file('polygons.shp')
>> >> > pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
>> >> > 
>> >> > error :
>> >> > 
>> >> > Traceback (most recent call last):
>> >> >   File
>> >> >   "/home/sarantis/testshapely/sumpointsinsidepolygon/testgeo.py",
>> >> >   line 7, in <module>
>> >> >     pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
>> >> >   File
>> >> >   "/usr/local/lib/python2.7/dist-packages/geopandas/tools/sjoin.py",
>> >> >   line 57, in sjoin
>> >> >     r_idx = np.concatenate(idxmatch.values)
>> >> > ValueError: need at least one array to concatenate
>> 
>> >> > any idea why ?
>> >> 
>> >> My crystal ball says that either points or polys is empty ;)
>> > 
>> > is not empty and yes i have two shapefiles from qgis.
>> 
>> Can I download those files somewhere?
>> 
>> > what is the error ?
>> 
>> No idea. Without those files I cannot run your code.
> 
> https://www.dropbox.com/s/2693nfi248z0y9q/files.zip?dl=0 with the
> shapefiles

It looks like there are no intersections in your data.
With the proviso that I've learned about the library only today I think you 
should get an empty result set rather than the ValueError.
Here's a way to reproduce the error (?) with the data provided in the 
project:

import geopandas
from geopandas import gpd

world = gpd.read_file(gpd.datasets.get_path('naturalearth_lowres'))
cities = gpd.read_file(gpd.datasets.get_path('naturalearth_cities'))
countries = world[['geometry', 'name']]

def find(items, name):
    # didn't find the idomatic way quickly, so
    for index, n in enumerate(items["name"]):
        if n == name:
            return items[index:index+1]
    raise ValueError

berlin = find(cities, "Berlin")
paris = find(cities, "Paris")
germany = find(countries, "Germany")

print(gpd.sjoin(berlin, germany))
print(gpd.sjoin(paris, germany)) # ValueError
             
$ python demo.py
                                        geometry name_left  index_right  \
175  POINT (13.39960276470055 52.52376452225116)    Berlin           41   

    name_right  
175    Germany  

[1 rows x 4 columns]
Traceback (most recent call last):
  File "demo.py", line 20, in <module>
    print(gpd.sjoin(paris, germany)) # ValueError
  File "/home/peter/virt/geopandas/lib/python3.4/site-
packages/geopandas/tools/sjoin.py", line 57, in sjoin
    r_idx = np.concatenate(idxmatch.values)
ValueError: need at least one array to concatenate
$

I suggest that you file a bug report.




From saxri89 at gmail.com  Sat Jan 14 11:11:17 2017
From: saxri89 at gmail.com (Xristos Xristoou)
Date: Sat, 14 Jan 2017 08:11:17 -0800 (PST)
Subject: geopandas bug ?
In-Reply-To: <mailman.6.1484409688.2442.python-list@python.org>
References: <2bffcdb3-066a-4f91-b00b-e390dd03c103@googlegroups.com>
 <o5d9rr$l7q$1@blaine.gmane.org>
 <mailman.4.1484401371.2442.python-list@python.org>
 <aaacba13-a82d-4eb8-9265-502ef9a6824d@googlegroups.com>
 <o5dcl8$6rl$1@blaine.gmane.org>
 <mailman.5.1484404236.2442.python-list@python.org>
 <bf010388-33e2-467d-88b9-c59fd6f9dbda@googlegroups.com>
 <o5dhv4$9ov$1@blaine.gmane.org>
 <mailman.6.1484409688.2442.python-list@python.org>
Message-ID: <4fe4140d-b424-42dd-a132-f7d76fce44bb@googlegroups.com>

?? ???????, 14 ?????????? 2017 - 6:01:39 ?.?. UTC+2, ? ??????? Peter Otten ??????:
> Xristos Xristoou wrote:
> 
> > ?? ???????, 14 ?????????? 2017 - 4:30:48 ?.?. UTC+2, ? ??????? Peter Otten
> > ??????:
> >> Xristos Xristoou wrote:
> >> 
> >> > ?? ???????, 14 ?????????? 2017 - 3:43:10 ?.?. UTC+2, ? ??????? Peter
> >> > Otten ??????:
> >> >> Xristos Xristoou wrote:
> >> >> 
> >> >> > i want  to create a simple spatial joing using geopandas but i thing
> >> >> > so geopandas has bug ?
> >> >> 
> >> >> Have you tried the examples on
> >> >> <http://geopandas.org/mergingdata.html>? Do they work? If yes, inspect
> >> >> your data, does it have the same format?
> >> 
> >> Looks like you chose to ignore the hard part.
> >>  
> >> >> > geopandas code :
> >> >> > 
> >> >> > from geopandas import gpd
> >> >> > import geopandas
> >> >> > points = geopandas.GeoDataFrame.from_file('points.shp') # or geojson
> >> >> > etc polys = geopandas.GeoDataFrame.from_file('polygons.shp')
> >> >> > pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
> >> >> > 
> >> >> > error :
> >> >> > 
> >> >> > Traceback (most recent call last):
> >> >> >   File
> >> >> >   "/home/sarantis/testshapely/sumpointsinsidepolygon/testgeo.py",
> >> >> >   line 7, in <module>
> >> >> >     pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
> >> >> >   File
> >> >> >   "/usr/local/lib/python2.7/dist-packages/geopandas/tools/sjoin.py",
> >> >> >   line 57, in sjoin
> >> >> >     r_idx = np.concatenate(idxmatch.values)
> >> >> > ValueError: need at least one array to concatenate
> >> 
> >> >> > any idea why ?
> >> >> 
> >> >> My crystal ball says that either points or polys is empty ;)
> >> > 
> >> > is not empty and yes i have two shapefiles from qgis.
> >> 
> >> Can I download those files somewhere?
> >> 
> >> > what is the error ?
> >> 
> >> No idea. Without those files I cannot run your code.
> > 
> > https://www.dropbox.com/s/2693nfi248z0y9q/files.zip?dl=0 with the
> > shapefiles
> 
> It looks like there are no intersections in your data.
> With the proviso that I've learned about the library only today I think you 
> should get an empty result set rather than the ValueError.
> Here's a way to reproduce the error (?) with the data provided in the 
> project:
> 
> import geopandas
> from geopandas import gpd
> 
> world = gpd.read_file(gpd.datasets.get_path('naturalearth_lowres'))
> cities = gpd.read_file(gpd.datasets.get_path('naturalearth_cities'))
> countries = world[['geometry', 'name']]
> 
> def find(items, name):
>     # didn't find the idomatic way quickly, so
>     for index, n in enumerate(items["name"]):
>         if n == name:
>             return items[index:index+1]
>     raise ValueError
> 
> berlin = find(cities, "Berlin")
> paris = find(cities, "Paris")
> germany = find(countries, "Germany")
> 
> print(gpd.sjoin(berlin, germany))
> print(gpd.sjoin(paris, germany)) # ValueError
>              
> $ python demo.py
>                                         geometry name_left  index_right  \
> 175  POINT (13.39960276470055 52.52376452225116)    Berlin           41   
> 
>     name_right  
> 175    Germany  
> 
> [1 rows x 4 columns]
> Traceback (most recent call last):
>   File "demo.py", line 20, in <module>
>     print(gpd.sjoin(paris, germany)) # ValueError
>   File "/home/peter/virt/geopandas/lib/python3.4/site-
> packages/geopandas/tools/sjoin.py", line 57, in sjoin
>     r_idx = np.concatenate(idxmatch.values)
> ValueError: need at least one array to concatenate
> $
> 
> I suggest that you file a bug report.

Mr.Peter Otten do you see my shapefiles ?have instersection 100 to 100 i use instersection on QGIS ad work fine


From __peter__ at web.de  Sat Jan 14 11:33:01 2017
From: __peter__ at web.de (Peter Otten)
Date: Sat, 14 Jan 2017 17:33:01 +0100
Subject: geopandas bug ?
References: <2bffcdb3-066a-4f91-b00b-e390dd03c103@googlegroups.com>
 <o5d9rr$l7q$1@blaine.gmane.org>
 <mailman.4.1484401371.2442.python-list@python.org>
 <aaacba13-a82d-4eb8-9265-502ef9a6824d@googlegroups.com>
 <o5dcl8$6rl$1@blaine.gmane.org>
 <mailman.5.1484404236.2442.python-list@python.org>
 <bf010388-33e2-467d-88b9-c59fd6f9dbda@googlegroups.com>
 <o5dhv4$9ov$1@blaine.gmane.org>
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 <4fe4140d-b424-42dd-a132-f7d76fce44bb@googlegroups.com>
Message-ID: <o5djrp$sj3$1@blaine.gmane.org>

Xristos Xristoou wrote:

>> I suggest that you file a bug report.
> 
> Mr.Peter Otten do you see my shapefiles ?have instersection 100 to 100 i
> use instersection on QGIS ad work fine

Yes, I downloaded the zipfile at

> https://www.dropbox.com/s/2693nfi248z0y9q/files.zip?dl=0 with the

and when I ran your code I got the very error that you saw. There are many 
NaN values in your data, so if it works elsewhere perhaps the data is 
corrupted in some way. I'm sorry I cannot help you any further. 

Good luck!



From saxri89 at gmail.com  Sat Jan 14 11:41:31 2017
From: saxri89 at gmail.com (Xristos Xristoou)
Date: Sat, 14 Jan 2017 08:41:31 -0800 (PST)
Subject: geopandas bug ?
In-Reply-To: <mailman.7.1484411623.2442.python-list@python.org>
References: <2bffcdb3-066a-4f91-b00b-e390dd03c103@googlegroups.com>
 <o5d9rr$l7q$1@blaine.gmane.org>
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 <o5dcl8$6rl$1@blaine.gmane.org>
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 <bf010388-33e2-467d-88b9-c59fd6f9dbda@googlegroups.com>
 <o5dhv4$9ov$1@blaine.gmane.org>
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?? ???????, 14 ?????????? 2017 - 6:33:54 ?.?. UTC+2, ? ??????? Peter Otten ??????:
> Xristos Xristoou wrote:
> 
> >> I suggest that you file a bug report.
> > 
> > Mr.Peter Otten do you see my shapefiles ?have instersection 100 to 100 i
> > use instersection on QGIS ad work fine
> 
> Yes, I downloaded the zipfile at
> 
> > https://www.dropbox.com/s/2693nfi248z0y9q/files.zip?dl=0 with the
> 
> and when I ran your code I got the very error that you saw. There are many 
> NaN values in your data, so if it works elsewhere perhaps the data is 
> corrupted in some way. I'm sorry I cannot help you any further. 
> 
> Good luck!

one more question,i have a idea what is wrong,but if my code work how to export spatial join "pointInPoly" to new shapefile ?


From __peter__ at web.de  Sat Jan 14 12:30:23 2017
From: __peter__ at web.de (Peter Otten)
Date: Sat, 14 Jan 2017 18:30:23 +0100
Subject: geopandas bug ?
References: <2bffcdb3-066a-4f91-b00b-e390dd03c103@googlegroups.com>
 <o5d9rr$l7q$1@blaine.gmane.org>
 <mailman.4.1484401371.2442.python-list@python.org>
 <aaacba13-a82d-4eb8-9265-502ef9a6824d@googlegroups.com>
 <o5dcl8$6rl$1@blaine.gmane.org>
 <mailman.5.1484404236.2442.python-list@python.org>
 <bf010388-33e2-467d-88b9-c59fd6f9dbda@googlegroups.com>
 <o5dhv4$9ov$1@blaine.gmane.org>
 <mailman.6.1484409688.2442.python-list@python.org>
 <4fe4140d-b424-42dd-a132-f7d76fce44bb@googlegroups.com>
 <o5djrp$sj3$1@blaine.gmane.org>
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Message-ID: <o5dn7b$5q1$1@blaine.gmane.org>

Xristos Xristoou wrote:

> ?? ???????, 14 ?????????? 2017 - 6:33:54 ?.?. UTC+2, ? ??????? Peter Otten
> ??????:
>> Xristos Xristoou wrote:
>> 
>> >> I suggest that you file a bug report.
>> > 
>> > Mr.Peter Otten do you see my shapefiles ?have instersection 100 to 100
>> > i use instersection on QGIS ad work fine
>> 
>> Yes, I downloaded the zipfile at
>> 
>> > https://www.dropbox.com/s/2693nfi248z0y9q/files.zip?dl=0 with the
>> 
>> and when I ran your code I got the very error that you saw. There are
>> many NaN values in your data, so if it works elsewhere perhaps the data
>> is corrupted in some way. I'm sorry I cannot help you any further.
>> 
>> Good luck!
> 
> one more question,i have a idea what is wrong,but if my code work how to
> export spatial join "pointInPoly" to new shapefile ?

You can find an object's methods in the interactive interpreter with dir()

>>> dir(pointInPoly)
['T', '_AXIS_ALIASES', '_AXIS_IALIASES', '_AXIS_LEN', '_AXIS_NAMES', 
'_AXIS_NUMBERS', '_AXIS_ORDERS', '_AXIS_REVERSED', '_AXIS_SLICEMAP', 

<snip>

'rmod', 'rmul', 'rotate', 'rpow', 'rsub', 'rtruediv', 'save', 'scale', 
'select', 'set_geometry', 'set_index', 'set_value', 'shape', 'shift', 
'simplify', 'sindex', 'skew', 'sort', 'sort_index', 'sortlevel', 'squeeze', 
'stack', 'std', 'sub', 'subtract', 'sum', 'swapaxes', 'swaplevel', 
'symmetric_difference', 'tail', 'take', 'to_clipboard', 'to_crs', 'to_csv', 
'to_dense', 'to_dict', 'to_excel', 'to_file', 'to_gbq', 'to_hdf', 'to_html', 
'to_json', 'to_latex', 'to_msgpack', 'to_panel', 'to_period', 'to_pickle', 
'to_records', 'to_sparse', 'to_sql', 'to_stata', 'to_string', 
'to_timestamp', 'to_wide', 'total_bounds', 'touches', 'translate', 
'transpose', 'truediv', 'truncate', 'tshift', 'type', 'tz_convert', 
'tz_localize', 'unary_union', 'union', 'unstack', 'update', 'values', 'var', 
'where', 'within', 'xs']

OK, that's quite a lot, but to_file() seems to be a good candidate. Let's 
see what it does:

>>> help(pointInPoly.to_file)
Help on method to_file in module geopandas.geodataframe:

to_file(filename, driver='ESRI Shapefile', schema=None, **kwargs) metod of 
geopandas.geodataframe.GeoDataFrame instance
    Write this GeoDataFrame to an OGR data source
    
    A dictionary of supported OGR providers is available via:
    >>> import fiona
    >>> fiona.supported_drivers
    
    Parameters
    ----------
    filename : string
        File path or file handle to write to.
    driver : string, default 'ESRI Shapefile'
        The OGR format driver used to write the vector file.
    schema : dict, default None
        If specified, the schema dictionary is passed to Fiona to
        better control how the file is written.
    
    The *kwargs* are passed to fiona.open and can be used to write
    to multi-layer data, store data within archives (zip files), etc.

Looks good, run it:

>>> pointInPoly.to_file("point_in_poly")

No error. Does it round-trip?

>>> pointInPoly == gpd.GeoDataFrame.from_file("point_in_poly")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3/dist-packages/pandas/core/ops.py", line 875, in f
    return self._compare_frame(other, func, str_rep)
  File "/usr/lib/python3/dist-packages/pandas/core/frame.py", line 2860, in 
_compare_frame
    raise ValueError('Can only compare identically-labeled '
ValueError: Can only compare identically-labeled DataFrame objects

Ouch, unfortunately not. Upon further inspection:

>>> pip.columns
Index(['geometry', 'index_righ', 'name_left', 'name_right'], dtype='object')
>>> pointInPoly.columns
Index(['geometry', 'name_left', 'index_right', 'name_right'], 
dtype='object')

Looks like column names are either corrupted or limited to 10 characters by 
default. Again I don't know how to overcome this, but as a special service 
here's the first hit for 'shp file column name limit' on a popular search 
engine:

http://gis.stackexchange.com/questions/15784/how-to-bypass-10-character-limit-of-field-name-in-shapefiles

I'm out of this now.




From duncan at invalid.invalid  Sat Jan 14 13:09:42 2017
From: duncan at invalid.invalid (duncan smith)
Date: Sat, 14 Jan 2017 18:09:42 +0000
Subject: geopandas bug ?
In-Reply-To: <f36a02ed-774e-45a2-926e-76f13fd4288d@googlegroups.com>
References: <2bffcdb3-066a-4f91-b00b-e390dd03c103@googlegroups.com>
 <GJqeA.959$DF1.330@fx02.iad>
 <f36a02ed-774e-45a2-926e-76f13fd4288d@googlegroups.com>
Message-ID: <HPteA.1069$Hz6.322@fx28.iad>

On 14/01/17 14:59, Xristos Xristoou wrote:
> ?? ???????, 14 ?????????? 2017 - 4:38:39 ?.?. UTC+2, ? ??????? duncan smith ??????:
>> On 14/01/17 11:18, Xristos Xristoou wrote:
>>> i want  to create a simple spatial joing using geopandas but i thing so geopandas has bug ?
>>>
>>>
>>>
>>> geopandas code :
>>>
>>> from geopandas import gpd
>>> import geopandas
>>> points = geopandas.GeoDataFrame.from_file('points.shp') # or geojson etc
>>> polys = geopandas.GeoDataFrame.from_file('polygons.shp')
>>> pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
>>>
>>> error :
>>>
>>> Traceback (most recent call last):
>>>   File "/home/sarantis/testshapely/sumpointsinsidepolygon/testgeo.py", line 7, in <module>
>>>     pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
>>>   File "/usr/local/lib/python2.7/dist-packages/geopandas/tools/sjoin.py", line 57, in sjoin
>>>     r_idx = np.concatenate(idxmatch.values)
>>> ValueError: need at least one array to concatenate
>>>
>>> and if i change the imports with the some code :
>>>
>>> import geopandas
>>> import pandas as pd
>>> import geopandas as gpd
>>> from geopandas import GeoDataFrame, read_file
>>> from geopandas.tools import sjoin
>>> from shapely.geometry import Point, mapping,shape
>>> import pandas as gpd
>>>
>>> i take that error :
>>>
>>>     pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
>>> AttributeError: 'module' object has no attribute 'sjoin'
>>>
>>>
>>> any idea why ?
>>>
>>
>>
>> import geopandas as gpd
>> import pandas as gpd
>>
>> Does pandas have an attribute 'sjoin'?
>>
>> Duncan
> 
> i dont know i follow detais i am newbie
> 

You import geopandas as gpd, then import pandas as gpd. So maybe you
think gpd refers to geopandas while it actually refers to pandas. I
don't know geopandas or pandas, but you should check your imports.

Duncan


From saxri89 at gmail.com  Sat Jan 14 13:29:45 2017
From: saxri89 at gmail.com (Xristos Xristoou)
Date: Sat, 14 Jan 2017 10:29:45 -0800 (PST)
Subject: geopandas bug ?
In-Reply-To: <HPteA.1069$Hz6.322@fx28.iad>
References: <2bffcdb3-066a-4f91-b00b-e390dd03c103@googlegroups.com>
 <GJqeA.959$DF1.330@fx02.iad>
 <f36a02ed-774e-45a2-926e-76f13fd4288d@googlegroups.com>
 <HPteA.1069$Hz6.322@fx28.iad>
Message-ID: <65c4340e-3edb-4703-8159-6927d975a8a2@googlegroups.com>

?? ???????, 14 ?????????? 2017 - 8:09:53 ?.?. UTC+2, ? ??????? duncan smith ??????:
> On 14/01/17 14:59, Xristos Xristoou wrote:
> > ?? ???????, 14 ?????????? 2017 - 4:38:39 ?.?. UTC+2, ? ??????? duncan smith ??????:
> >> On 14/01/17 11:18, Xristos Xristoou wrote:
> >>> i want  to create a simple spatial joing using geopandas but i thing so geopandas has bug ?
> >>>
> >>>
> >>>
> >>> geopandas code :
> >>>
> >>> from geopandas import gpd
> >>> import geopandas
> >>> points = geopandas.GeoDataFrame.from_file('points.shp') # or geojson etc
> >>> polys = geopandas.GeoDataFrame.from_file('polygons.shp')
> >>> pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
> >>>
> >>> error :
> >>>
> >>> Traceback (most recent call last):
> >>>   File "/home/sarantis/testshapely/sumpointsinsidepolygon/testgeo.py", line 7, in <module>
> >>>     pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
> >>>   File "/usr/local/lib/python2.7/dist-packages/geopandas/tools/sjoin.py", line 57, in sjoin
> >>>     r_idx = np.concatenate(idxmatch.values)
> >>> ValueError: need at least one array to concatenate
> >>>
> >>> and if i change the imports with the some code :
> >>>
> >>> import geopandas
> >>> import pandas as pd
> >>> import geopandas as gpd
> >>> from geopandas import GeoDataFrame, read_file
> >>> from geopandas.tools import sjoin
> >>> from shapely.geometry import Point, mapping,shape
> >>> import pandas as gpd
> >>>
> >>> i take that error :
> >>>
> >>>     pointInPoly = gpd.sjoin(points, polys, how='left',op='within')
> >>> AttributeError: 'module' object has no attribute 'sjoin'
> >>>
> >>>
> >>> any idea why ?
> >>>
> >>
> >>
> >> import geopandas as gpd
> >> import pandas as gpd
> >>
> >> Does pandas have an attribute 'sjoin'?
> >>
> >> Duncan
> > 
> > i dont know i follow detais i am newbie
> > 
> 
> You import geopandas as gpd, then import pandas as gpd. So maybe you
> think gpd refers to geopandas while it actually refers to pandas. I
> don't know geopandas or pandas, but you should check your imports.
> 
> Duncan

@Duncan i see that and i remove line with pandas ans no change


From rodrick.brown at gmail.com  Sat Jan 14 13:46:19 2017
From: rodrick.brown at gmail.com (Rodrick Brown)
Date: Sat, 14 Jan 2017 13:46:19 -0500
Subject: multiprocessing.Process call blocks other processes from running
Message-ID: <CABRP1o-YRJZNLZ+Kh9evr_48ycTssF2wLEO0HWa-hUFWci9S6A@mail.gmail.com>

I'm trying to implement a script that tracks how much space certain
applications are using and send a metric to a statsd service for realtime
analysis however when running this code it nots forking multiple processes
its still running sequential at some point the forking was working but I
can't seem to figure out where I went wrong please advise

I'm just trying to keep track of the growth rate of certain dirs these dirs
have hundreds of thousands of files and take sometime to run I use du as it
runs much faster than os.walk() and it also returns the correct compressed
size on the file system pythons getsize() does not.

Thanks.

from datadog import initialize
from datadog import api
from datadog import statsd
import os
import subprocess
from import Process, Queue
from datadog import ThreadStats
import time
import datetime
from hashlib import md5

options = {
  'api_key': 'xx',
  'app_key': 'xx'
}

def getWhispererLogsDirSize(clientcfg, queue):
  clientName, logPath = clientcfg.items()[0]
  totalSize = 0
  clientResult = {}
  for item in os.listdir(logPath):
    logDir = logPath + "/" + item
    try:
      totalSize = totalSize +
int(subprocess.check_output(["du","-s",logDir]).split('\t')[0])
    except subprocess.CalledProcessError:
      print("Error processing {0} skipping.....".format(logDir))
      continue
  clientResult[clientName] = [os.path.basename(logPath),totalSize]
  queue.put(clientResult)
  return

if __name__ == '__main__':

  title = 'Whisperer client marketdata usage'
  text = 'This simple utility sends whisperer logs into datadog based on
client usage on disk'
  tags = ['version:1']
  initialize(**options)
  #api.Event.create(title=title, text=text, tags=tags)
  #stats = ThreadStats()
  #stats.start()
  queue = Queue()
  jobs = []
  clients = [
    {'xx1':'/mnt/auto/glusterfs/app/NYC01-xx-PROD-01'},
    {'xx2':'/mnt/auto/glusterfs/app/NYC01-xx-PROD-01'},
    {'xx3':'/mnt/auto/glusterfs/app/NYC01-xx-PROD-01'},
    {'xx4':'/mnt/auto/glusterfs/app/NYC01-xx-PROD-01'}
  ]
  tags = []
  while True:
    for client in clients:
      stats = ThreadStats()
      stats.start()
      p = Process(target=getWhispererLogsDirSize, args=(client,queue,))
      jobs.append(p)
      p.start()
      p.join()
      clientinfo = queue.get()

      clientName = clientinfo.values()[0][0]
      clientPath = clientinfo.keys()[0]
      clientLogSize = clientinfo.values()[0][1]
      tags = [clientName,clientPath]
      aggregation_key = md5(clientName).hexdigest()

      print(clientName, clientPath, clientLogSize)
      with open('/tmp/dogstatd_out.log', 'a+') as fp:
        fp.write("{0} {1} {2}
{3}\n".format(str(datetime.datetime.now()),clientName, clientPath,
clientLogSize))

stats.gauge('whisperer.marketdata.clientlogsize',int(clientLogSize),tags=tags)


From jcasale at activenetwerx.com  Sat Jan 14 14:05:48 2017
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Sat, 14 Jan 2017 19:05:48 +0000
Subject: multiprocessing.Process call blocks other processes from running
In-Reply-To: <CABRP1o-YRJZNLZ+Kh9evr_48ycTssF2wLEO0HWa-hUFWci9S6A@mail.gmail.com>
References: <CABRP1o-YRJZNLZ+Kh9evr_48ycTssF2wLEO0HWa-hUFWci9S6A@mail.gmail.com>
Message-ID: <cd3d4dec57d2423dbc4f8f2a216f2f73@activenetwerx.com>

>  while True:
>    for client in clients:
>      stats = ThreadStats()
>      stats.start()
>      p = Process(target=getWhispererLogsDirSize, args=(client,queue,))
>      jobs.append(p)
>      p.start()
>      p.join()

You start one client then join before starting the next...

Start them all and push the pointer the resulting process object into a collection.
Then use whatever semantics you desire to wait them all...

jlc


From python at mrabarnett.plus.com  Sat Jan 14 15:10:02 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Sat, 14 Jan 2017 20:10:02 +0000
Subject: multiprocessing.Process call blocks other processes from running
In-Reply-To: <cd3d4dec57d2423dbc4f8f2a216f2f73@activenetwerx.com>
References: <CABRP1o-YRJZNLZ+Kh9evr_48ycTssF2wLEO0HWa-hUFWci9S6A@mail.gmail.com>
 <cd3d4dec57d2423dbc4f8f2a216f2f73@activenetwerx.com>
Message-ID: <fe7b3593-1b7e-a355-9f04-f0578d085839@mrabarnett.plus.com>

On 2017-01-14 19:05, Joseph L. Casale wrote:
>>  while True:
>>    for client in clients:
>>      stats = ThreadStats()
>>      stats.start()
>>      p = Process(target=getWhispererLogsDirSize, args=(client,queue,))
>>      jobs.append(p)
>>      p.start()
>>      p.join()
>
> You start one client then join before starting the next...
>
> Start them all and push the pointer the resulting process object into a collection.
> Then use whatever semantics you desire to wait them all...
>
To me it also looks slightly odd that you're creating a ThreadStats
instance each time around the loop, and the only other reference to it
is to the last one created, and that line's indentation puts it outside
the """if __name__ == '__main__':""" block.



From python at lucidity.plus.com  Sat Jan 14 16:13:26 2017
From: python at lucidity.plus.com (Erik)
Date: Sat, 14 Jan 2017 21:13:26 +0000
Subject: How can I make a sentinel value NOT be initialized in a
 class/method - OOP?
In-Reply-To: <c49823f1-3d05-4101-a766-4ac5bca034f4@googlegroups.com>
References: <c49823f1-3d05-4101-a766-4ac5bca034f4@googlegroups.com>
Message-ID: <64df2ad9-3944-ff95-74e1-9d83ea8ad1a5@lucidity.plus.com>

[Replying to direct email. David - please respond to the list so that 
you can receive other people's suggestions also]

Hi David,

On 14/01/17 15:30, David D wrote:
 > 1)  No this is not homework, I am doing this all on my own.

In that case I apologise - I gave you the benefit of the doubt though as 
I was only half-suspicious. FWIW, listing specific constructs that must 
be used is often a thing that a tutor would write in an assignment 
(because the purpose of the assignment is to get you to learn about 
those particular constructs). That's what raised the flag for me. Anyway ...

 > 2) I am changing the class to cars.
 >
 > 3) A second question arose that I thought would work, but I am getting
 > this error :*can't assign to a function call*
 >
 > What I am trying to do is this pseudo code :

Firstly, there's little point in posting pseudo code if you are 
reporting a specific compiler or run-time error. The errors you get are 
very specific to your code and in some cases are caused by *subtle* 
things in your code. We generally need to see the actual code (or a 
cut-down example) that allows the subtleties to be described to you.

 > count= 0
 >
 > class car
 > initialize all of the values and put self so they are available to the
 > entire class
 > def __init__(self, model...)
 >   self.mode=model etc
 >
 >
 > while loop
 > input model =what is the model
 > input serial = what is the serial
 > input doors = how many doors
 > count = count + 1
 > #create the instance/object
 > mycar (count) = car(model, serial, doors)
 >
 > input do you want another car in the database?
 > if yes
 >   continue
 > if no
 >   break
 >
 > The issue is that when creating an object/instance, python won't let me
 > use this syntax of having -- car(count) which would give me multiple
 > objects (car1, car2, car3 etc) with the count variable.  I am not 
sure why.

The syntax "foo(spam)" will *call* the function "foo" and pass it the 
value "spam". It doesn't make any sense to _assign a value_ to a 
function call operation (you're effectively trying to assign a value - 
the thing after the '=' - to another value - the return value of the 
function call).

So, what is "mycar"? How do you create it?

In Python, the built-in structure for a group of objects which can be 
dynamically extended with new entries in the way you want is a list. 
Create an empty one with:

mycar = []

or

mycar = list()

Lists have an 'append()' method which will add the parameter it is 
called with to the end of the list object it is called on:

mycar.append(car(model, serial, doors))


You don't have to worry about keeping track of 'count'. Lists will grow 
dynamically as you add things. Use "len(mycar)" to see how many items it 
holds and "for vehicle in mycar:" to step through them all or "mycar[n]" 
to address as specific entry.

 From the Python prompt, type "help(list)"

Hope that helps.
E.


From steve+python at pearwood.info  Sat Jan 14 18:32:07 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Sun, 15 Jan 2017 10:32:07 +1100
Subject: multiprocessing.Process call blocks other processes from running
References: <CABRP1o-YRJZNLZ+Kh9evr_48ycTssF2wLEO0HWa-hUFWci9S6A@mail.gmail.com>
 <mailman.9.1484419628.2442.python-list@python.org>
Message-ID: <587ab4f9$0$1588$c3e8da3$5496439d@news.astraweb.com>

On Sun, 15 Jan 2017 05:46 am, Rodrick Brown wrote:

> at some point the forking was working

Then whatever you changed, you should change back to the way it was.

That's the most important lesson here: never make two or more unrelated
changes to a program unless you have a backup of the working file.

An excellent way to manage this process is by using a revision control
system like Mercurial (hg) or equivalent. But at the very least, whenever
you change a working program, you should confirm it is still working before
making the next change.





-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From hawat.thufir at gmail.com  Sun Jan 15 12:19:34 2017
From: hawat.thufir at gmail.com (Thufir Hawat)
Date: Sun, 15 Jan 2017 09:19:34 -0800 (PST)
Subject: nfldb API
Message-ID: <alpine.DEB.2.20.1701150908540.9504@qbtr.obhaprzr.arg>

I'm looking at nfldb:

pip install --user nfldb

which is on github:

https://github.com/BurntSushi/nfldb/wiki/More-examples


Coming at this from Java, how would I hook into nfldb with Java?  Or, 
perhaps, run the code in Jython?

I'm sure there's a general solution or approach, would appreciate any 
pointers.  Perhaps simply using JNI to leverage the work that's gone into 
this library already.



thanks,

Thufir


From daviddschool at gmail.com  Sun Jan 15 14:58:16 2017
From: daviddschool at gmail.com (David D)
Date: Sun, 15 Jan 2017 11:58:16 -0800 (PST)
Subject: working with classes, inheritance, _str_ returns and a list
Message-ID: <4f0680eb-2678-4ea2-b622-a6cd5a19e0a0@googlegroups.com>

I am creating a parent class and a child class.  I am inheriting from the parent with an additional attribute in the child class.  I am using __str__ to return the information.  When I run the code, it does exactly what I want, it returns the __str__ information.  This all works great. 

BUT

1) I want what is returned to be appended to a list (the list will be my database)
2) I append the information to the list that I created
3) Whenever I print the list, I get a memory location

So how do I take the information that is coming out of the child class (as a __str__ string), and keep it as a string so I can append it to the list?

pseudo code

allcars=[]

parent class()
   def init (self, model, wheels, doors)
      self.model= model etc

child class (parent)
   def init(self, model, wheels, doors, convertible)
       super(child, self).__init__(model, wheels, doors)
       self.convertible = convertible

   def __str__(self):
        return "model: " + self.model + etc

car1= child(model, wheels, doors, convertible)
print car1



Here is where it goes wrong for me


allcars.append(car1)

I am sure I am making a silly mistake in here somewhere...







From rosuav at gmail.com  Sun Jan 15 15:08:04 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 16 Jan 2017 07:08:04 +1100
Subject: working with classes, inheritance, _str_ returns and a list
In-Reply-To: <4f0680eb-2678-4ea2-b622-a6cd5a19e0a0@googlegroups.com>
References: <4f0680eb-2678-4ea2-b622-a6cd5a19e0a0@googlegroups.com>
Message-ID: <CAPTjJmr6QpUcwF+XSss2drZNz=wKV40FUA5bb=Ejj4skuKxggg@mail.gmail.com>

On Mon, Jan 16, 2017 at 6:58 AM, David D <daviddschool at gmail.com> wrote:
> I am creating a parent class and a child class.  I am inheriting from the parent with an additional attribute in the child class.  I am using __str__ to return the information.  When I run the code, it does exactly what I want, it returns the __str__ information.  This all works great.
>
> BUT
>
> 1) I want what is returned to be appended to a list (the list will be my database)
> 2) I append the information to the list that I created
> 3) Whenever I print the list, I get a memory location

Technically it's an identity, not a memory location, but yes, I know
what you mean here.

What's happening is that printing a list actually prints the *repr* of
an object, rather than its str. The easiest change is to rename your
__str__ function to __repr__; if you don't need them to be different,
define __repr__ and it'll be used for printing as well.

By the way, you'll find that Python 3 makes some things with class
definitions a bit easier. There are less traps to potentially fall
into. I strongly suggest using the latest Python (currently 3.6) or
something close to it (3.5 is in a lot of Linux distributions).

All the best!

ChrisA


From michael.s011235 at gmail.com  Sun Jan 15 15:55:14 2017
From: michael.s011235 at gmail.com (Michael S)
Date: Sun, 15 Jan 2017 21:55:14 +0100
Subject: Problem while building Python 3.6 from source.
In-Reply-To: <CAPTjJmoUm-UUU+8nb7-+jCVFAXqWvkCFm9FufOE8-ZUMDtW6_Q@mail.gmail.com>
References: <CAGGEVu-1x-7b=psOQN39sx_6Yf0MFZmMAB5+-CEisbS0LBUAgQ@mail.gmail.com>
 <CAPTjJmoUm-UUU+8nb7-+jCVFAXqWvkCFm9FufOE8-ZUMDtW6_Q@mail.gmail.com>
Message-ID: <CAGGEVu_MeCSrzQPMK6YjoqA11DM_dgpuu0Z9=ebUFpu2DohV2A@mail.gmail.com>

Thanks Thomas and ChrisA!

@Thomas: I don't know.. Unfortunately I am not as skilled as to be
able to find out..

@ChrisA: I tried your advice and think it worked. So, I just used $
./configure and then $ make. Then I was not sure, whether it had
worked so I used $ make test and got a fairly long result. At the end
there was a line like "test successful". Nevertheless not all of the
tests were successful.

So, now I got some questions:

1) Why did not all of the tests in $ make test succeed? But the end
line was "test successful". That confuses me.

2) This is more general. In order to get the build-dependencies I used
# apt-get build-dep python3.4. I also googled for the build
dependencies but did not find anything. So, how could I actually
figure out the build dependencies for Python3.6?


On Fri, Jan 13, 2017 at 7:19 PM, Chris Angelico <rosuav at gmail.com> wrote:
> On Sat, Jan 14, 2017 at 5:00 AM, Michael S <michael.s011235 at gmail.com> wrote:
>> Hello,
>> I am new to this mailing-list and I really don't know whether this
>> mail should belong to python-dev. Please tell me, if so.
>
> Hi and welcome! This kind of thing is best on this list initially.
>
>> Unfortunately, I have got the following problem: I wanted to build and
>> install Python 3.6 from source but did not succeed.
>> To clarify my situation, I got as an operating system Debian jessie
>> 8.6 and I used the xz compressed source tarball from
>> https://www.python.org/downloads/release/python-360/.
>> Concerning the build dependencies: I just executed:
>> $ sudo apt-get build-dep python3.4 (since 3.6 and 3.5 did not work).
>
> That should be fine; the build dependencies of Python don't tend to
> change frequently. Jessie shipped with Python 3.4 but nothing newer,
> so there won't be packages for python3.5 or python3.6.
>
>> Then I executed ./configure --enable-optimizations and make -j4 (I got 4 cores).
>> The output of make ended like:
>> 'make: *** [profile-opt] Error 2'.
>
> That just means that something went wrong. You'd have to scroll up to
> find the actual cause of the error.
>
>> I had redirected the output and error of the configure and make commands via
>> $ make -j4 &> /home/username/make_output.txt.
>> Nevertheless I got an error to the console:
>> '*** Error in ./python'" free(): invalid next size (normal):
>> 0x00000000015bdf90 ***'.
>> Due to these error messages (this one and the one at the end of make)
>> I think the build was not successful.
>>
>> How to solve this problem?
>>
>> Of course I could send you the output and error files.
>
> The first thing I'd do would be to try a non-optimized build. Set your
> current build tree aside and re-extract into a new directory (that
> way, when you go back to playing with optimized builds, you don't have
> to redo the work), and run configure with no arguments. I'd also be
> inclined to run make with no arguments; there've been issues with
> parallel builds in enough projects that I've gotten into the habit of
> "problem? do it the slow way". If that build also fails, scroll up a
> bit and find where stuff failed.
>
> Are you familiar with building programs from source? If not, the best
> solution might be to post the entire log, but ideally, you should be
> able to skim through the last part of the log and report the actual
> problem that's cropping up.
>
> ChrisA
> --
> https://mail.python.org/mailman/listinfo/python-list


From rosuav at gmail.com  Sun Jan 15 16:09:17 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 16 Jan 2017 08:09:17 +1100
Subject: Problem while building Python 3.6 from source.
In-Reply-To: <CAGGEVu_MeCSrzQPMK6YjoqA11DM_dgpuu0Z9=ebUFpu2DohV2A@mail.gmail.com>
References: <CAGGEVu-1x-7b=psOQN39sx_6Yf0MFZmMAB5+-CEisbS0LBUAgQ@mail.gmail.com>
 <CAPTjJmoUm-UUU+8nb7-+jCVFAXqWvkCFm9FufOE8-ZUMDtW6_Q@mail.gmail.com>
 <CAGGEVu_MeCSrzQPMK6YjoqA11DM_dgpuu0Z9=ebUFpu2DohV2A@mail.gmail.com>
Message-ID: <CAPTjJmqSarAqVJWOcwdzEwNnoDreWo6g=aRVgvBkiVoPNj6bHQ@mail.gmail.com>

On Mon, Jan 16, 2017 at 7:55 AM, Michael S <michael.s011235 at gmail.com> wrote:
> @ChrisA: I tried your advice and think it worked. So, I just used $
> ./configure and then $ make. Then I was not sure, whether it had
> worked so I used $ make test and got a fairly long result. At the end
> there was a line like "test successful". Nevertheless not all of the
> tests were successful.

Can you run:

$ ./python

That should fire up the newly-built interpreter.

> So, now I got some questions:
>
> 1) Why did not all of the tests in $ make test succeed? But the end
> line was "test successful". That confuses me.

Not sure - I'd have to see what the actual output was. Most likely
there were some tests skipped; not all tests apply on all platforms.
For instance, there are a number of Windows-specific tests, which
won't be running on your system. Also, Python includes a number of
optional modules, and if you don't have their dependencies, you get a
Python that's fully functional with the exception of that/those
module(s).

> 2) This is more general. In order to get the build-dependencies I used
> # apt-get build-dep python3.4. I also googled for the build
> dependencies but did not find anything. So, how could I actually
> figure out the build dependencies for Python3.6?

They don't often change between versions. Certainly between 3.4 and
3.6 you should have no problems. It's only an issue if you're porting
to a brand new platform or something, and then you have to do the
usual dance of "compile, read the error, grab a new library, rinse and
repeat".

ChrisA


From python at lucidity.plus.com  Sun Jan 15 16:27:58 2017
From: python at lucidity.plus.com (Erik)
Date: Sun, 15 Jan 2017 21:27:58 +0000
Subject: working with classes, inheritance, _str_ returns and a list
In-Reply-To: <4f0680eb-2678-4ea2-b622-a6cd5a19e0a0@googlegroups.com>
References: <4f0680eb-2678-4ea2-b622-a6cd5a19e0a0@googlegroups.com>
Message-ID: <6f235a6f-cb53-a613-a4c1-da3de72990a9@lucidity.plus.com>

Hi,

On 15/01/17 19:58, David D wrote:
> I am creating a parent class and a child class.  I am inheriting from
> the parent with an additional attribute in the child class.  I am
> using __str__ to return the information.  When I run the code, it
> does exactly what I want, it returns the __str__ information.  This
> all works great.
>
> BUT
>
> 1) I want what is returned to be appended to a list (the list will be
> my database) 2) I append the information to the list that I created
> 3) Whenever I print the list, I get a memory location
>
> So how do I take the information that is coming out of the child
> class (as a __str__ string), and keep it as a string so I can append
> it to the list?

[snip]

> Here is where it goes wrong for me
>
> allcars.append(car1)

This adds the object (of the child or parent class) to the list. If you
_really_ want the *string* returned by __str__() to be appended to the
list then you would do:

allcars.append(str(car1))

(The str() function returns what the object's __str__() method returns
if it has one - otherwise it will return SOME sort of string
representation of your object, but you can't rely on the format of that).

I'm a bit confused though as to why you would want to create that object
only store its __str__() value and discard the object itself.

E.


From frank at chagford.com  Mon Jan 16 00:25:59 2017
From: frank at chagford.com (Frank Millman)
Date: Mon, 16 Jan 2017 07:25:59 +0200
Subject: working with classes, inheritance, _str_ returns and a list
In-Reply-To: <4f0680eb-2678-4ea2-b622-a6cd5a19e0a0@googlegroups.com>
References: <4f0680eb-2678-4ea2-b622-a6cd5a19e0a0@googlegroups.com>
Message-ID: <o5hlh4$1sb$1@blaine.gmane.org>

"David D"  wrote in message 
news:4f0680eb-2678-4ea2-b622-a6cd5a19e0a0 at googlegroups.com...
>
> I am creating a parent class and a child class.  I am inheriting from the 
> parent with an additional attribute in the child class.  I am using 
> __str__ to return the information.  When I run > the code, it does exactly 
> what I want, it returns the __str__ information.  This all works great.
>
> BUT
>
> 1) I want what is returned to be appended to a list (the list will be my 
> database)
> 2) I append the information to the list that I created
> 3) Whenever I print the list, I get a memory location
>

You have been given an explanation, and a couple of workarounds.

Here is another possible workaround, which may help depending on how you 
actually print the list -

If you are saying -
    for item in list:
        print(item)

you can say instead -
  for item in list:
        print(str(item))

HTH

Frank Millman




From girishrkhasnis at gmail.com  Mon Jan 16 00:32:25 2017
From: girishrkhasnis at gmail.com (Girish Khasnis)
Date: Mon, 16 Jan 2017 11:02:25 +0530
Subject: Python Error
Message-ID: <CANj0iegMqRep+=22+inhsdAADz-5RLg0rXkd1TiZ0wVHgOW+xQ@mail.gmail.com>

Hi,


I am unable to install Python on my system. After installing Python I get
the below error when I try to open Python.

[image: Inline image 1]

Regards
Girish


From jessealama at fastmail.fm  Mon Jan 16 00:39:34 2017
From: jessealama at fastmail.fm (Jesse Alama)
Date: Mon, 16 Jan 2017 06:39:34 +0100
Subject: Python Web Scrapping : Within href readonly those value that have
 href in it
In-Reply-To: <mailman.47.1484411622.2441.python-list@python.org>
References: <mailman.47.1484411622.2441.python-list@python.org>
Message-ID: <1484545174.2046826.848802760.2F41A44F@webmail.messagingengine.com>

To complement what Peter wrote: I'd approach this problem using
XPath. XPath is a query language for XML/HTML documents; it's a great
tool to have in your web scraping toolbox (among other tasks). With
Python's excellent lxml library you can do some XPath processing. Here's
how I might tackle this problem:

== [ scrape.py ] ======================================================

from lxml import etree

# ...somehow get HTML/XML into the variable xml

root = etree.HTML(xml)

hrefs = root.xpath("//a[@href and starts-with(@href, 'http://')]/@href")

# magic =========>  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

print(hrefs) # if you want to see what this looks like

== [ end scrape.py ] ==================================================

The argument to the xpath method here is an XPath expression.  The
overall form is:

    //a[.....]/@href

The '//a' at the beginning means: starting at the root node of the
document, find all a (anchor) elements that match the condition
specified by ".....".  The '/@href' at the end means: give me the href
attribute of the nodes (if any) that remain.

Looking inside the square brackets (what's known as the predicate in the
XPath world), we find

    @href and starts-with(@href, 'http://')

The 'and' bit should be clear (there are two conditions that need to be
checked).  The first part says: the a element should have an href
attribute.  The second part says that the value of the href element had
better start with 'http://'.

In fact, we could simplify the predicate to

  starts-with(@href, 'http://')

If an element does not even have an href attribute, its value does not
start with 'http://'. It's not an error, and no exception will be
thrown, when the XPath evaluator applies the starts-with function to an
a element that does not have an href attribute.

Hope this helps.

Best regards,

Jesse

--
Jesse Alama
http://xml.sh


From pkpearson at nowhere.invalid  Mon Jan 16 00:47:58 2017
From: pkpearson at nowhere.invalid (Peter Pearson)
Date: 16 Jan 2017 05:47:58 GMT
Subject: Sockets: IPPROTO_IP not supported
Message-ID: <ee354dFb503U1@mid.individual.net>

Trying to sniff Ethernet packets, I do this:

    s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_IP)

but it results in this:

    $ sudo python3 sniff_survey.py 
    Traceback (most recent call last):
      File "sniff_survey.py", line 118, in <module>
        s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_IP)
      File "/usr/lib/python3.2/socket.py", line 94, in __init__
        _socket.socket.__init__(self, family, type, proto, fileno)
    socket.error: [Errno 93] Protocol not supported

Anybody know what I'm doing wrong?  (Python 3.2.3 under Debian 3.2.84-1.)

-- 
To email me, substitute nowhere->runbox, invalid->com.


From frank at chagford.com  Mon Jan 16 00:57:16 2017
From: frank at chagford.com (Frank Millman)
Date: Mon, 16 Jan 2017 07:57:16 +0200
Subject: working with classes, inheritance, _str_ returns and a list
In-Reply-To: <o5hlh4$1sb$1@blaine.gmane.org>
References: <4f0680eb-2678-4ea2-b622-a6cd5a19e0a0@googlegroups.com>
 <o5hlh4$1sb$1@blaine.gmane.org>
Message-ID: <o5hnbq$q36$1@blaine.gmane.org>

"Frank Millman"  wrote in message news:o5hlh4$1sb$1 at blaine.gmane.org...
>
> If you are saying -
>     for item in list:
>         print(item)
>
> you can say instead -
>   for item in list:
>         print(str(item))
>

This is not correct, sorry.

print(item) will automatically print the string representation of item, so 
it makes no difference.

The principle is still correct, though.

If you want to convert what you call the memory address of the item to the 
string representation, just wrap it in str(...)

Frank




From frank at chagford.com  Mon Jan 16 01:03:19 2017
From: frank at chagford.com (Frank Millman)
Date: Mon, 16 Jan 2017 08:03:19 +0200
Subject: working with classes, inheritance, _str_ returns and a list
In-Reply-To: <o5hnbq$q36$1@blaine.gmane.org>
References: <4f0680eb-2678-4ea2-b622-a6cd5a19e0a0@googlegroups.com>
 <o5hlh4$1sb$1@blaine.gmane.org> <o5hnbq$q36$1@blaine.gmane.org>
Message-ID: <o5hnn4$dop$1@blaine.gmane.org>

"Frank Millman"  wrote in message news:o5hnbq$q36$1 at blaine.gmane.org...
>
> "Frank Millman"  wrote in message news:o5hlh4$1sb$1 at blaine.gmane.org...
> >
> > If you are saying -
> >     for item in list:
> >         print(item)
> >
> > you can say instead -
> >   for item in list:
> >         print(str(item))
> >
>
> This is not correct, sorry.
>
> print(item) will automatically print the string representation of item, so 
> it makes no difference.
>
> The principle is still correct, though.
>
> If you want to convert what you call the memory address of the item to the 
> string representation, just wrap it in str(...)
>

I keep thinking of something else just after I have posted - sorry about 
that.

When you say you print the list, maybe you are literally doing the 
following -
    print(list)

In that case, the solution is to turn it into a list comprehension, and 
apply str() to each item -
    print([str(item) for item in list])

Frank




From adnan.connexus at gmail.com  Mon Jan 16 02:55:02 2017
From: adnan.connexus at gmail.com (Adnan Sheikh)
Date: Sun, 15 Jan 2017 23:55:02 -0800 (PST)
Subject: matrix from matrix
In-Reply-To: <fb5f7ed4-4902-4c20-b5cd-4d86a923c2d1@googlegroups.com>
References: <fb5f7ed4-4902-4c20-b5cd-4d86a923c2d1@googlegroups.com>
Message-ID: <9f06e031-fba6-4863-bbab-fde485d1c655@googlegroups.com>

My apologies for not providing enough information.

I'll share my code attempt shortly.

Cheers for your help :)

Shei


From tjreedy at udel.edu  Mon Jan 16 04:24:08 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Mon, 16 Jan 2017 04:24:08 -0500
Subject: Python Error
In-Reply-To: <CANj0iegMqRep+=22+inhsdAADz-5RLg0rXkd1TiZ0wVHgOW+xQ@mail.gmail.com>
References: <CANj0iegMqRep+=22+inhsdAADz-5RLg0rXkd1TiZ0wVHgOW+xQ@mail.gmail.com>
Message-ID: <o5i3fk$74k$1@blaine.gmane.org>

On 1/16/2017 12:32 AM, Girish Khasnis wrote:
> Hi,
>
>
> I am unable to install Python on my system. After installing Python I get
> the below error when I try to open Python.
>
> [image: Inline image 1]

Copy and paste the error message.  This is text only list.


-- 
Terry Jan Reedy



From jcasale at activenetwerx.com  Mon Jan 16 05:17:06 2017
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Mon, 16 Jan 2017 10:17:06 +0000
Subject: Sockets: IPPROTO_IP not supported
In-Reply-To: <ee354dFb503U1@mid.individual.net>
References: <ee354dFb503U1@mid.individual.net>
Message-ID: <32fb9ad66f854486889cb7af607e6fff@activenetwerx.com>

> Trying to sniff Ethernet packets, I do this:
>
>    s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_IP)
>
> but it results in this:
>
>     $ sudo python3 sniff_survey.py 
>     Traceback (most recent call last):
>       File "sniff_survey.py", line 118, in <module>
>         s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_IP)
>       File "/usr/lib/python3.2/socket.py", line 94, in __init__
>         _socket.socket.__init__(self, family, type, proto, fileno)
>     socket.error: [Errno 93] Protocol not supported
>
> Anybody know what I'm doing wrong?  (Python 3.2.3 under Debian 3.2.84-1.)

Have a look at the bottom of this SO question:
http://stackoverflow.com/questions/5385312/ipproto-ip-vs-ipproto-tcp-ipproto-udp



From info at egenix.com  Mon Jan 16 06:35:15 2017
From: info at egenix.com (eGenix Team: M.-A. Lemburg)
Date: Mon, 16 Jan 2017 12:35:15 +0100
Subject: =?UTF-8?Q?ANN:_Python_Meeting_D=c3=bcsseldorf_-_18.01.2017?=
Message-ID: <6ac5851e-cc56-c128-cb08-267b711973be@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.

                   Mittwoch, 18.01.2017, 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-2017-01-18
________________________________________________________________________

NEUIGKEITEN

 * Bereits angemeldete Vortr?ge:

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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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   Google Street View: http://bit.ly/11sCfiw

________________________________________________________________________

EINLEITUNG

Das Python Meeting D?sseldorf ist eine regelm??ige Veranstaltung in
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 * 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:

 * http://www.youtube.com/pyddf/

Veranstaltet wird das Meeting von der eGenix.com GmbH, Langenfeld,
in Zusammenarbeit mit Clark Consulting & Research, D?sseldorf:

 * http://www.egenix.com/
 * http://www.clark-consulting.eu/

________________________________________________________________________

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Das Python Meeting D?sseldorf nutzt eine Mischung aus (Lightning)
Talks und offener Diskussion.

Vortr?ge k?nnen vorher angemeldet werden, oder auch spontan w?hrend
des Treffens eingebracht werden. Ein Beamer mit XGA Aufl?sung
steht zur Verf?gung.

(Lightning) Talk Anmeldung bitte formlos per EMail an info at pyddf.de

________________________________________________________________________

KOSTENBETEILIGUNG

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.

________________________________________________________________________

ANMELDUNG

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 Experts (#1, Jan 16 2017)
>>> Python Projects, Coaching and Consulting ...  http://www.egenix.com/
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________________________________________________________________________

::: We implement business ideas - efficiently in both time and costs :::

   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/
                      http://www.malemburg.com/



From p.f.moore at gmail.com  Mon Jan 16 07:09:06 2017
From: p.f.moore at gmail.com (Paul Moore)
Date: Mon, 16 Jan 2017 04:09:06 -0800 (PST)
Subject: A detailed description on virtualenv's packaging dependecies?
 (pip, easy_install, wheel, setuptools, distlib, etc.)
In-Reply-To: <05080bd7-5903-4621-9cc5-e5c9be04e80d@googlegroups.com>
References: <05080bd7-5903-4621-9cc5-e5c9be04e80d@googlegroups.com>
Message-ID: <7a1a87bc-5cdd-4b20-b305-86a1f303de19@googlegroups.com>

On Friday, 13 January 2017 09:27:21 UTC, haraldn... at gmail.com  wrote:
> I was working on a bugfix for Virtualenv, regarding very long shebang lines that are breaking things. In the process, I realized that if I want really fix to my particular issue it likely needs to be done on the lower level of Python package management. I started with pip, moved to setuptools and now set my sight on distlib.
> 
> Can someone describe the specific dependencies of all the *packaging* libraries that `virtualenv` uses? And the dependencies between them?
> 
> I believe that virtualenv directly imports `pip`, `easy_install` and `wheel`. Those in turn import `setuptools` and `distlib`. Am I so lucky as to assume that distlib in the lowest-level library used by all the rest in virtualenv for packages?

I believe distlib is the lowest level. But I think you're looking at the problem wrongly. From the issue you reported, the problem you're hitting is that your OS limits the length of paths you can use in a "shebang" line, and the pathname for your virtualenv exceeds that limit. And as a result, script wrappers for Python modules installed in the virtualenv fail because the shebang line is too long.

So it's not virtualenv creating the environment that needs to be fixed, but *anything* that installs wrappers that point to the environment Python with a shebang line (wherever they are installed to).

By patching distlib, you'll catch the case of installing packages into the virtualenv using pip and distil (once they update distlib). But I don't think you will catch easy_install (which uses setuptools, which uses its own wrapper script) or setup.py install (which again most likely uses setuptools). And nothing will catch 3rd party tools that do their own thing.

So if you want to try to minimise the impact of the OS limitation, you can patch both distlib and setuptools and probably get most things (actually, there's probably not much that doesn't use pip, so just patching distlib will probably get the majority of cases). You'll have to manually apply the workaround to any scripts you write yourself that you want to run with the virtualenv's Python.

Or you can just accept the limitation and use shorter pathnames.

If you're willing to accept the limitation, and it's possible to somehow determine from the OS what it allows, then getting virtualenv to warn if you use a "too long" pathname might be an alternative solution.

Paul


From valkrem at yahoo.com  Mon Jan 16 07:45:45 2017
From: valkrem at yahoo.com (Val Krem)
Date: Mon, 16 Jan 2017 12:45:45 -0000
Subject: data frame
In-Reply-To: <o3k3o7$onp$1@blaine.gmane.org>
References: <235400868.1750803.1482525599916.ref@mail.yahoo.com>
 <235400868.1750803.1482525599916@mail.yahoo.com>
 <o3k3o7$onp$1@blaine.gmane.org>
Message-ID: <1242451632.1794626.1482530144997@mail.yahoo.com>

Here is the first few lines of the data


s1.csv 
size,w1,h1
512,214,26
123,250,34
234,124,25
334,213,43

and the script

    a=pd.read_csv("s1.csv", skipinitialspace=True).keys()
    print(a)
i see the following

Index(['size', 'w1', 'h1'], dtype='object')



when I wanted to add the two columns; then I get the following message.

a=pd.read_csv("s1.csv", skipinitialspace=True).keys()
a['test']=a['w1'] + a['h1']
print(a)




data/apps/Intel/intelpython35/lib/python3.5/site-packages/pandas/indexes/base.py:1393: VisibleDeprecationWarning: using a non-integer number instead of an integer will result in an error in the future
return getitem(key)
Traceback (most recent call last):
File "tt.py", line 12, in <module>
a['test']=a['w1'] + a['h1']
File "/data/apps/Intel/intelpython35/lib/python3.5/site-packages/pandas/indexes/base.py", line 1393, in __getitem__
return getitem(key)
IndexError: only integers, slices (`:`), ellipsis (`...`), numpy.newaxis (`None`) and integer or boolean arrays are valid indices



On Friday, December 23, 2016 3:09 PM, Peter Otten <__peter__ at web.de> wrote:
Val Krem via Python-list wrote:

> Hi all,
>
> #!/usr/bin/env python
> import sys
> import csv
> import numpy as np
> import pandas as  pd
>
> a= pd.read_csv("s1.csv")
> print(a)
>
>      size  w1  h1
> 0  512  214  26
> 1  123  250  34
> 2  234  124  25
> 3  334  213  43
> 4  a45  223  32
> 5  a12  214  26
>
> I wanted to create a new column by adding the two column values
> as follows
>
> a['test'] = a['w1'] + a['h1']
>
> Traceback (most recent call last):
> File
> "/data/apps/Intel/intelpython35/lib/python3.5/site-
packages/pandas/indexes/base.py",
> line 2104, in get_loc return self._engine.get_loc(key) File
> "pandas/index.pyx", line 139, in pandas.index.IndexEngine.get_loc
> (pandas/index.c:4152) File "pandas/index.pyx", line 161, in
> pandas.index.IndexEngine.get_loc (pandas/index.c:4016) File
> "pandas/src/hashtable_class_helper.pxi", line 732, in
> pandas.hashtable.PyObjectHashTable.get_item (pandas/hashtable.c:13153)
> File "pandas/src/hashtable_class_helper.pxi", line 740, in
> pandas.hashtable.PyObjectHashTable.get_item (pandas/hashtable.c:13107)
> KeyError: 'w1'
>
> During handling of the above exception, another exception occurred:
>
> Traceback (most recent call last):
> File "tt.py", line 16, in <module>
> a['test']=a['w1'] + a['h1']
>
> File "pandas/src/hashtable_class_helper.pxi", line 740, in
> pandas.hashtable.PyObjectHashTable.get_item (pandas/hashtable.c:13107)
> KeyError: 'w1'
>
> Can someone help me what the problem is?
>
> Thank you in advance

Have a look at a.keys(). I suspect that the column name has extra space:

>>> pd.read_csv("s1.csv").keys()
Index([u'size', u' w1', u' h1'], dtype='object')

I that's what you see you can fix it by reading the csv with
skipinitialspace=True:

>>> pd.read_csv("s1.csv", skipinitialspace=True).keys()
Index([u'size', u'w1', u'h1'], dtype='object')


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


/data/apps/Intel/intelpython35/lib/python3.5/site-packages/pandas/indexes/base.py:1393: VisibleDeprecationWarning: using a non-integer number instead of an integer will result in an error in the future
return getitem(key)
Traceback (most recent call last):
File "tt.py", line 12, in <module>
a['test']=a['w1'] + a['h1']
File "/data/apps/Intel/intelpython35/lib/python3.5/site-packages/pandas/indexes/base.py", line 1393, in __getitem__
return getitem(key)
IndexError: only integers, slices (`:`), ellipsis (`...`), numpy.newaxis (`None`) and integer or boolean arrays are valid indices







On Friday, December 23, 2016 3:09 PM, Peter Otten <__peter__ at web.de> wrote:
Val Krem via Python-list wrote:

> Hi all,
> 
> #!/usr/bin/env python
> import sys
> import csv
> import numpy as np
> import pandas as  pd
> 
> a= pd.read_csv("s1.csv")
> print(a)
> 
>      size   w1   h1
> 0  512  214   26
> 1  123  250   34
> 2  234  124   25
> 3  334  213   43
> 4  a45  223   32
> 5  a12  214   26
> 
> I wanted to create a new column by adding the two column values
> as follows
> 
> a['test'] = a['w1'] + a['h1']
> 
> Traceback (most recent call last):
> File
> "/data/apps/Intel/intelpython35/lib/python3.5/site-
packages/pandas/indexes/base.py",
> line 2104, in get_loc return self._engine.get_loc(key) File
> "pandas/index.pyx", line 139, in pandas.index.IndexEngine.get_loc
> (pandas/index.c:4152) File "pandas/index.pyx", line 161, in
> pandas.index.IndexEngine.get_loc (pandas/index.c:4016) File
> "pandas/src/hashtable_class_helper.pxi", line 732, in
> pandas.hashtable.PyObjectHashTable.get_item (pandas/hashtable.c:13153)
> File "pandas/src/hashtable_class_helper.pxi", line 740, in
> pandas.hashtable.PyObjectHashTable.get_item (pandas/hashtable.c:13107)
> KeyError: 'w1'
> 
> During handling of the above exception, another exception occurred:
> 
> Traceback (most recent call last):
> File "tt.py", line 16, in <module>
> a['test']=a['w1'] + a['h1']
> 
> File "pandas/src/hashtable_class_helper.pxi", line 740, in
> pandas.hashtable.PyObjectHashTable.get_item (pandas/hashtable.c:13107)
> KeyError: 'w1'
> 
> Can someone help me what the problem is?
> 
> Thank you in advance

Have a look at a.keys(). I suspect that the column name has extra space:

>>> pd.read_csv("s1.csv").keys()
Index([u'size', u' w1', u' h1'], dtype='object')

I that's what you see you can fix it by reading the csv with 
skipinitialspace=True:

>>> pd.read_csv("s1.csv", skipinitialspace=True).keys()
Index([u'size', u'w1', u'h1'], dtype='object')


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


From p.f.moore at gmail.com  Mon Jan 16 11:44:37 2017
From: p.f.moore at gmail.com (Paul Moore)
Date: Mon, 16 Jan 2017 08:44:37 -0800 (PST)
Subject: Running Virtualenv with a custom distlib?
In-Reply-To: <2bc1125c-eb70-49bc-bd90-ebeaa9741258@googlegroups.com>
References: <2bc1125c-eb70-49bc-bd90-ebeaa9741258@googlegroups.com>
Message-ID: <985384eb-0336-4836-b24c-9350807969db@googlegroups.com>

On Friday, 13 January 2017 09:27:59 UTC, haraldn... at gmail.com  wrote:
> I want to do some development on `distlib`, and in the process run the code via `virtualenv` which has distlib as a dependency.
> 
> That is, not run the process inside a virtualenv, but run virtualenv's code using a custom dependency. What are the steps I need to go through to achieve this?
> 
> It seems to me that normal package management (`pip`) is not possible here.

virtualenv bundles a local copy of pip. And that pip in turn vendors distlib. So you'd need to build a new pip wheel with your customised version of distlib vendored in it, and then build virtualenv with that version of pip embedded.

(You can avoid the last step by putting the new pip wheel in a virtualenv_embedded directory next to virtualenv.py, but you'd have to check the docs and maybe sources to ensure I remembered that right. Also your pip wheel would need to be a higher version than the embedded one, or it would get ignored).

Paul


From israel at ravnalaska.net  Mon Jan 16 13:06:02 2017
From: israel at ravnalaska.net (Israel Brewster)
Date: Mon, 16 Jan 2017 09:06:02 -0900
Subject: Error handling in context managers
Message-ID: <8932DADB-D790-4A62-849A-4CB48D76E65A@ravnalaska.net>

I generally use context managers for my SQL database connections, so I can just write code like:

with psql_cursor() as cursor:
    <do whatever>

And the context manager takes care of making a connection (or getting a connection from a pool, more likely), and cleaning up after the fact (such as putting the connection back in the pool), even if something goes wrong. Simple, elegant, and works well.

The problem is that, from time to time, I can't get a connection, the result being that cursor is None, and attempting to use it results in an AttributeError. So my instinctive reaction is to wrap the potentially offending code in a try block, such that if I get that AttributeError I can decide how I want to handle the "no connection" case. This, of course, results in code like:

try:
	with psql_cursor() as cursor:
		<do whatever>
except AttributeError as e:
	<handle no-connection case>

I could also wrap the code within the context manager in an if block checking for if cursor is not None, but while perhaps a bit clearer as to the purpose, now I've got an extra check that will not be needed most of the time (albeit a quite inexpensive check).

The difficulty I have with either of these solutions, however, is that they feel ugly to me - and wrapping the context manager in a try block almost seems to defeat the purpose of the context manager in the first place - If I'm going to be catching errors anyway, why not just do the cleanup there rather than hiding it in the context manager?

Now don't get me wrong - neither of these issues is terribly significant to me. I'll happily wrap all the context manager calls in a try block and move on with life if that it in fact the best option. It's just my gut says "there should be a better way", so I figured I'd ask: *is* there a better way? Perhaps some way I could handle the error internally to the context manager, such that it just dumps me back out? Of course, that might not work, given that I may need to do something different *after* the context manager, depending on if I was able to get a connection, but it's a thought. Options?

-----------------------------------------------
Israel Brewster
Systems Analyst II
Ravn Alaska
5245 Airport Industrial Rd
Fairbanks, AK 99709
(907) 450-7293
-----------------------------------------------






From rosuav at gmail.com  Mon Jan 16 13:25:54 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 17 Jan 2017 05:25:54 +1100
Subject: Error handling in context managers
In-Reply-To: <8932DADB-D790-4A62-849A-4CB48D76E65A@ravnalaska.net>
References: <8932DADB-D790-4A62-849A-4CB48D76E65A@ravnalaska.net>
Message-ID: <CAPTjJmpG3jSh45SQB2Ows-RvoMqyTzNqd_jLeSD2n=mpAaAdgg@mail.gmail.com>

On Tue, Jan 17, 2017 at 5:06 AM, Israel Brewster <israel at ravnalaska.net> wrote:
> I generally use context managers for my SQL database connections, so I can just write code like:
>
> with psql_cursor() as cursor:
>     <do whatever>
>
> And the context manager takes care of making a connection (or getting a connection from a pool, more likely), and cleaning up after the fact (such as putting the connection back in the pool), even if something goes wrong. Simple, elegant, and works well.
>
> The problem is that, from time to time, I can't get a connection, the result being that cursor is None, and attempting to use it results in an AttributeError.

My question is: If you can't get a connection, why do you get back
None? Wouldn't it be better for psql_cursor() to raise an exception?

ChrisA


From __peter__ at web.de  Mon Jan 16 13:52:59 2017
From: __peter__ at web.de (Peter Otten)
Date: Mon, 16 Jan 2017 19:52:59 +0100
Subject: Error handling in context managers
References: <8932DADB-D790-4A62-849A-4CB48D76E65A@ravnalaska.net>
Message-ID: <o5j4q7$rcd$1@blaine.gmane.org>

Israel Brewster wrote:

> I generally use context managers for my SQL database connections, so I can
> just write code like:
> 
> with psql_cursor() as cursor:
>     <do whatever>
> 
> And the context manager takes care of making a connection (or getting a
> connection from a pool, more likely), and cleaning up after the fact (such
> as putting the connection back in the pool), even if something goes wrong.
> Simple, elegant, and works well.
> 
> The problem is that, from time to time, I can't get a connection, the
> result being that cursor is None, and attempting to use it results in an
> AttributeError. So my instinctive reaction is to wrap the potentially
> offending code in a try block, such that if I get that AttributeError I
> can decide how I want to handle the "no connection" case. This, of course,
> results in code like:
> 
> try:
> with psql_cursor() as cursor:
> <do whatever>
> except AttributeError as e:
> <handle no-connection case>
> 
> I could also wrap the code within the context manager in an if block
> checking for if cursor is not None, but while perhaps a bit clearer as to
> the purpose, now I've got an extra check that will not be needed most of
> the time (albeit a quite inexpensive check).

That seems to be the cleanest approach.

> The difficulty I have with either of these solutions, however, is that
> they feel ugly to me - and wrapping the context manager in a try block
> almost seems to defeat the purpose of the context manager in the first
> place - If I'm going to be catching errors anyway, why not just do the
> cleanup there rather than hiding it in the context manager?
> 
> Now don't get me wrong - neither of these issues is terribly significant
> to me. I'll happily wrap all the context manager calls in a try block and
> move on with life if that it in fact the best option. It's just my gut
> says "there should be a better way", so I figured I'd ask: *is* there a
> better way? Perhaps some way I could handle the error internally to the
> context manager, such that it just dumps me back out? Of course, that
> might not work, given that I may need to do something different *after*
> the context manager, depending on if I was able to get a connection, but
> it's a thought. Options?

The problem is that there is no way to skip the with-block. It would be nice 
if you could raise a special exception in the __enter__() method that would 
achieve that.

For the time being you could 

(1) abuse a for loop

def psql_cursor():
    try:
      yield make_cursor()
    except NoConnection:
      pass

for cursor in psql_cursor():
    ...

or you could 

(2) return something that hopefully raises an exception soon, e. g.

$ cat conditional_context.py
import sys
from contextlib import contextmanager

class Cursor:
    def execute(self, sql):
        print("EXECUTING", sql)

class Exit(Exception):
    pass

class FailingCursor:
    def __getattr__(self, name):
        raise Exit

@contextmanager
def cursor():
    try:
        yield FailingCursor() if "--fail" in sys.argv else Cursor()
    except Exit:
        print("no connection")
        

with cursor() as cs:
    cs.execute("insert into...")
        
              
$ python3 conditional_context.py
EXECUTING insert into...
$ python3 conditional_context.py --fail
no connection

Option (1) works, but looks wrong while option (2) looks better, but does 
not work reliably in the general case, e. g. when you perform some costly 
calculation before the first attribute access.



From steve+python at pearwood.info  Mon Jan 16 14:07:55 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Tue, 17 Jan 2017 06:07:55 +1100
Subject: Error handling in context managers
References: <8932DADB-D790-4A62-849A-4CB48D76E65A@ravnalaska.net>
 <mailman.34.1484590983.2442.python-list@python.org>
Message-ID: <587d1a0d$0$1606$c3e8da3$5496439d@news.astraweb.com>

On Tue, 17 Jan 2017 05:06 am, Israel Brewster wrote:

> I generally use context managers for my SQL database connections, so I can
> just write code like:
> 
> with psql_cursor() as cursor:
>     <do whatever>
> 
> And the context manager takes care of making a connection (or getting a
> connection from a pool, more likely), and cleaning up after the fact (such
> as putting the connection back in the pool), even if something goes wrong.
> Simple, elegant, and works well.
> 
> The problem is that, from time to time, I can't get a connection, the
> result being that cursor is None, 

Seriously? psql_cursor().__enter__ returns None instead of failing? That
sounds like a poor design to me.

Where is this psql_cursor coming from?


> and attempting to use it results in an 
> AttributeError. So my instinctive reaction is to wrap the potentially
> offending code in a try block, such that if I get that AttributeError I
> can decide how I want to handle the "no connection" case. This, of course,
> results in code like:
> 
> try:
> with psql_cursor() as cursor:
> <do whatever>
> except AttributeError as e:
> <handle no-connection case>

Except that isn't necessarily the no-connection case. It could be *any*
AttributeError anywhere in the entire with block.

> I could also wrap the code within the context manager in an if block
> checking for if cursor is not None, but while perhaps a bit clearer as to
> the purpose, now I've got an extra check that will not be needed most of
> the time (albeit a quite inexpensive check).

It's cheap, it's only needed once (at the start of the block), it isn't
subject to capturing the wrong exception... I would definitely write:

with psql_cursor() as cursor:
    if cursor is not None:
        <do whatever>


> The difficulty I have with either of these solutions, however, is that
> they feel ugly to me - and wrapping the context manager in a try block
> almost seems to defeat the purpose of the context manager in the first
> place - If I'm going to be catching errors anyway, why not just do the
> cleanup there rather than hiding it in the context manager?

Context managers don't necessarily swallow exceptions (although they can).
That's not what they're for. Context managers are intended to avoid:

try:
    ...
finally:
    ...


*not* try...except blocks. If you need a try...except, then you could avoid
using the context manager and re-invent the wheel:

try:
    ...
except:
    ...
finally:
    # do whatever cleanup the context manager already defines
    # but now you have to do it yourself



or you can let the context manager do what it does, and write your own code
to do what you do:

try:
    with ...:
       ...
except:
    ...



[...]
> says "there should be a better way", so I figured I'd ask: *is* there a
> better way? Perhaps some way I could handle the error internally to the
> context manager, such that it just dumps me back out? 

That's what's supposed to happen:

py> with open('foobarbaz') as f:
...     pass
...
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
FileNotFoundError: [Errno 2] No such file or directory: 'foobarbaz'


Notice that the context manager simply raises an exception on failure, which
I can catch or not as I so choose, rather than returning None.

I really think that the problem here is the design of psql_cursor().


> Of course, that 
> might not work, given that I may need to do something different *after*
> the context manager, depending on if I was able to get a connection, but
> it's a thought. Options?





-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From marko at pacujo.net  Mon Jan 16 14:29:42 2017
From: marko at pacujo.net (Marko Rauhamaa)
Date: Mon, 16 Jan 2017 21:29:42 +0200
Subject: Error handling in context managers
References: <8932DADB-D790-4A62-849A-4CB48D76E65A@ravnalaska.net>
 <mailman.34.1484590983.2442.python-list@python.org>
 <587d1a0d$0$1606$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <8760leiz15.fsf@elektro.pacujo.net>

Steve D'Aprano <steve+python at pearwood.info>:

> or you can let the context manager do what it does, and write your own code
> to do what you do:
>
> try:
>     with ...:
>        ...
> except:
>     ...

Even better:

    try:
       a = open(...)
    except ...:
       ...
    with a:
       ...

You want to catch exceptions immediately after (potentially) raising
them.


Marko


From pkpearson at nowhere.invalid  Mon Jan 16 17:24:46 2017
From: pkpearson at nowhere.invalid (Peter Pearson)
Date: 16 Jan 2017 22:24:46 GMT
Subject: Sockets: IPPROTO_IP not supported
References: <ee354dFb503U1@mid.individual.net>
 <32fb9ad66f854486889cb7af607e6fff@activenetwerx.com>
 <mailman.29.1484561840.2442.python-list@python.org>
Message-ID: <ee4vhdFoulgU1@mid.individual.net>

On Mon, 16 Jan 2017 10:17:06 +0000, Joseph L. Casale wrote:
>> Trying to sniff Ethernet packets, I do this:
>>
>>    s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_IP)
>>
>> but it results in this:
>>
>>     $ sudo python3 sniff_survey.py 
>>     Traceback (most recent call last):
>>       File "sniff_survey.py", line 118, in <module>
>>         s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_IP)
>>       File "/usr/lib/python3.2/socket.py", line 94, in __init__
>>         _socket.socket.__init__(self, family, type, proto, fileno)
>>     socket.error: [Errno 93] Protocol not supported
>>
>> Anybody know what I'm doing wrong?  (Python 3.2.3 under Debian 3.2.84-1.)
>
> Have a look at the bottom of this SO question:
> http://stackoverflow.com/questions/5385312/ipproto-ip-vs-ipproto-tcp-ipproto-udp

That discussion was helpful.  Thanks.

Still, I'm not out of the woods.  From bmargulies's answer at that link,

   "IPPROTO_IP is for raw IP packets",

which sounds like what I want.  But when I use AF_INET, SOCK_RAW, and
IPPROTO_IP, I get the "Protocol not supported" error as shown above.
>From the link you provided and "man socket", I was inspired to flail
about, finding this:

 domain    type        protocol     result
 --------  -------     ----------  -----------------
 AF_INET   SOCK_RAW    IPPROTO_IP  "Protocol not supported"
 AF_INET   SOCK_RAW    IPPROTO_IPIP Sees nothing
 AF_INET   SOCK_RAW    IPPROTO_TCP Sees TCP traffic, no "dig", no "ping"
 AF_INET   SOCK_RAW    IPPROTO_UDP Sees DNS ("dig", but not "ping")
 AF_INET   SOCK_RAW    IPPROTO_ICMP Sees "ping", but not "dig"
 AF_INET   SOCK_RAW    IPPROTO_RAW Sees nothing
 AF_INET   SOCK_RAW    0           "Protocol not supported"
 AF_INET   SOCK_STREAM 0           "Transport endpoint is not connected"
 AF_INET   SOCK_DGRAM  0           Sees nothing
 AF_INET   SOCK_RDM    0           "Socket type not supported"
 AF_IPX    SOCK_RAW    IPPROTO_RAW "Socket type not supported"
 AF_PACKET SOCK_RAW    IPPROTO_RAW Sees nothing
 AF_PACKET SOCK_RAW    IPPROTO_TCP Sees nothing

So I can receive TCP traffic through one socket, and UDP traffic through
another socket, and ICMP traffic through a third; but I would like to
see all IP packets, regardless of higher-level protocol, and would
prefer to get them through a single pipe.  (Perhaps it's unreasonable
for me to ask something as high-level as a socket to give me something
as low-level as a raw packet.)

My starting point, by the way, was sample code for "a very simple
network sniffer", presented at docs.python.org/3/library/socket.html,
which opened the socket with 

  s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_IP)

which is the line that results in the "Protocol not supported" error
on my system.  (That sample code is labelled as being "for Windows",
so the document is not in error.)

-- 
To email me, substitute nowhere->runbox, invalid->com.


From tjreedy at udel.edu  Mon Jan 16 17:27:56 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Mon, 16 Jan 2017 17:27:56 -0500
Subject: Error handling in context managers
In-Reply-To: <8932DADB-D790-4A62-849A-4CB48D76E65A@ravnalaska.net>
References: <8932DADB-D790-4A62-849A-4CB48D76E65A@ravnalaska.net>
Message-ID: <o5jhd9$dta$1@blaine.gmane.org>

On 1/16/2017 1:06 PM, Israel Brewster wrote:
> I generally use context managers for my SQL database connections, so I can just write code like:
>
> with psql_cursor() as cursor:
>     <do whatever>
>
> And the context manager takes care of making a connection (or getting a connection from a pool, more likely), and cleaning up after the fact (such as putting the connection back in the pool), even if something goes wrong. Simple, elegant, and works well.
>
> The problem is that, from time to time, I can't get a connection, the result being that cursor is None,

This would be like open('bad file') returning None instead of raising 
FileNotFoundError.

> and attempting to use it results in an AttributeError.

Just as None.read would.

Actually, I have to wonder about your claim.  The with statement would 
look for cursor.__enter__ and then cursor.__exit__, and None does not 
have those methods.  In other words, the expression following 'with' 
must evaluate to a context manager and None is not a context manager.

 >>> with None: pass

Traceback (most recent call last):
   File "<pyshell#3>", line 1, in <module>
     with None: pass
AttributeError: __enter__

Is psql_cursor() returning a fake None object with __enter__ and 
__exit__ methods?

-- 
Terry Jan Reedy



From sg552 at hotmail.co.uk  Mon Jan 16 17:42:43 2017
From: sg552 at hotmail.co.uk (Rotwang)
Date: Mon, 16 Jan 2017 14:42:43 -0800 (PST)
Subject: tokenize.untokenize adding line continuation characters
Message-ID: <dfc7f799-6d98-4413-94e7-df85c83e4d28@googlegroups.com>

Here's something odd I've found with the tokenize module: tokenizing 'if x:\n    y' and then untokenizing the result adds '\\\n' to the end. Attempting to tokenize the result again fails because of the backslash continuation with nothing other than a newline after it. On the other hand, if the original string ends with a newline then it works fine. Can anyone explain why this happens?

I'm using Python 3.4.3 on Windows 8. Copypasted from iPython:


import tokenize, io

tuple(tokenize.tokenize(io.BytesIO('if x:\n    y'.encode()).readline))
Out[2]: 
(TokenInfo(type=56 (ENCODING), string='utf-8', start=(0, 0), end=(0, 0), line=''),
 TokenInfo(type=1 (NAME), string='if', start=(1, 0), end=(1, 2), line='if x:\n'),
 TokenInfo(type=1 (NAME), string='x', start=(1, 3), end=(1, 4), line='if x:\n'),
 TokenInfo(type=52 (OP), string=':', start=(1, 4), end=(1, 5), line='if x:\n'),
 TokenInfo(type=4 (NEWLINE), string='\n', start=(1, 5), end=(1, 6), line='if x:\n'),
 TokenInfo(type=5 (INDENT), string='    ', start=(2, 0), end=(2, 4), line='    y'),
 TokenInfo(type=1 (NAME), string='y', start=(2, 4), end=(2, 5), line='    y'),
 TokenInfo(type=6 (DEDENT), string='', start=(3, 0), end=(3, 0), line=''),
 TokenInfo(type=0 (ENDMARKER), string='', start=(3, 0), end=(3, 0), line=''))

tokenize.untokenize(_).decode()
Out[3]: 'if x:\n    y\\\n'

tuple(tokenize.tokenize(io.BytesIO(_.encode()).readline))
---------------------------------------------------------------------------
TokenError                                Traceback (most recent call last)
<ipython-input-4-6bd8f83c1114> in <module>()
----> 1 tuple(tokenize.tokenize(io.BytesIO(_.encode()).readline))

C:\Program Files\Python34\lib\tokenize.py in _tokenize(readline, encoding)
    558         else:                                  # continued statement
    559             if not line:
--> 560                 raise TokenError("EOF in multi-line statement", (lnum, 0))
    561             continued = 0
    562 

TokenError: ('EOF in multi-line statement', (3, 0))


From steve+comp.lang.python at pearwood.info  Mon Jan 16 21:46:53 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Tue, 17 Jan 2017 13:46:53 +1100
Subject: tokenize.untokenize adding line continuation characters
References: <dfc7f799-6d98-4413-94e7-df85c83e4d28@googlegroups.com>
Message-ID: <587d859e$0$2804$c3e8da3$76491128@news.astraweb.com>

On Tuesday 17 January 2017 09:42, Rotwang wrote:

> Here's something odd I've found with the tokenize module: 
[...]
> Copypasted from iPython:

It's not impossible that iPython is doing something funny with the tokenize 
module. Before reporting it as a bug, I recommend that you confirm that it also 
occurs in the standard Python interpreter and isn't iPython specific.

Just run your same code but directly from python, not the interactive iPython 
console.



-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From greg.ewing at canterbury.ac.nz  Tue Jan 17 00:01:03 2017
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Tue, 17 Jan 2017 18:01:03 +1300
Subject: Error handling in context managers
In-Reply-To: <mailman.34.1484590983.2442.python-list@python.org>
References: <8932DADB-D790-4A62-849A-4CB48D76E65A@ravnalaska.net>
 <mailman.34.1484590983.2442.python-list@python.org>
Message-ID: <ee5mohFu7qfU1@mid.individual.net>

Israel Brewster wrote:
> The problem is that, from time to time, I can't get a connection, the result
> being that cursor is None,

That's your problem right there -- you want a better-behaved
version of psql_cursor().

def get_psql_cursor():
    c = psql_cursor()
    if c is None:
       raise CantGetAConnectionError()
    return c

with get_psql_cursor() as c:
    ...

-- 
Greg


From greg.ewing at canterbury.ac.nz  Tue Jan 17 00:01:54 2017
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Tue, 17 Jan 2017 18:01:54 +1300
Subject: Error handling in context managers
In-Reply-To: <mailman.37.1484605711.2442.python-list@python.org>
References: <8932DADB-D790-4A62-849A-4CB48D76E65A@ravnalaska.net>
 <o5jhd9$dta$1@blaine.gmane.org>
 <mailman.37.1484605711.2442.python-list@python.org>
Message-ID: <ee5mq2Fu7qfU2@mid.individual.net>

Terry Reedy wrote:
> Traceback (most recent call last):
>   File "<pyshell#3>", line 1, in <module>
>     with None: pass
> AttributeError: __enter__

Like he said, you get an AttributeError!

-- 
Greg


From steve+comp.lang.python at pearwood.info  Tue Jan 17 02:05:35 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Tue, 17 Jan 2017 18:05:35 +1100
Subject: Emulating Final classes in Python
Message-ID: <587dc242$0$1601$c3e8da3$5496439d@news.astraweb.com>

I wish to emulate a "final" class using Python, similar to bool:

py> class MyBool(bool):
...     pass
... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: type 'bool' is not an acceptable base type


It doesn't have to be absolutely bulletproof, but anyone wanting to subclass my 
class should need to work for it, which hopefully will tell them that they're 
doing something unsupported.

Any hints?




-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From ethan at stoneleaf.us  Tue Jan 17 02:25:58 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Mon, 16 Jan 2017 23:25:58 -0800
Subject: Emulating Final classes in Python
In-Reply-To: <587dc242$0$1601$c3e8da3$5496439d@news.astraweb.com>
References: <587dc242$0$1601$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <587DC706.4090902@stoneleaf.us>

On 01/16/2017 11:05 PM, Steven D'Aprano wrote:
> I wish to emulate a "final" class using Python, similar to bool:
>
> py> class MyBool(bool):
> ...     pass
> ...
> Traceback (most recent call last):
>    File "<stdin>", line 1, in <module>
> TypeError: type 'bool' is not an acceptable base type
>
>
> It doesn't have to be absolutely bulletproof, but anyone wanting to subclass my
> class should need to work for it, which hopefully will tell them that they're
> doing something unsupported.
>
> Any hints?

Use a metaclass.  Have the metaclass create the first one, and refuse to make any others.

--
~Ethan~


From steve+comp.lang.python at pearwood.info  Tue Jan 17 02:32:53 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Tue, 17 Jan 2017 18:32:53 +1100
Subject: Emulating Final classes in Python
References: <587dc242$0$1601$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <587dc8a8$0$1589$c3e8da3$5496439d@news.astraweb.com>

On Tuesday 17 January 2017 18:05, Steven D'Aprano wrote:

> I wish to emulate a "final" class using Python, similar to bool:
[...]
> Any hints?

I may have a solution: here's a singleton (so more like None than bools) where 
instantiating the class returns the singleton, and subclassing the class fails:



class DoneMeta(type):
    _final = None
    def __new__(meta, name, bases, ns):
        if meta._final is None:
            meta._final = cls = super().__new__(meta, name, bases, ns)
            return cls
        elif meta._final in bases:  # Not sure this check is needed.
            raise TypeError('base class is final and cannot be subclassed')


class DoneType(metaclass=DoneMeta):
    __slots__ = ()
    _instance = None
    def __new__(cls):
        if cls._instance is None:
            cls._instance = inst = super().__new__(cls)
            return inst
        return cls._instance
    def __repr__(self):
        return '<DONE>'


DONE = DoneType()

del DoneType, DoneMeta
assert type(DONE)() is DONE



Thoughts? Any improvements or criticism? (Apart from "don't do it" :-)


Of course this is Python, and so we can actually dig under the hood and make a 
new instance if we really try:

py> x = object.__new__(type(DONE))
py> x
<DONE>
py> x is DONE
False


and similarly there are probably ways to bypass the anti-subclassing code. But 
the way I see it, if you're doing that, you either know what you're doing in 
which case good on you, or you don't, in which case you deserve whatever 
happens to you :-)



-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From __peter__ at web.de  Tue Jan 17 03:34:13 2017
From: __peter__ at web.de (Peter Otten)
Date: Tue, 17 Jan 2017 09:34:13 +0100
Subject: Error handling in context managers
References: <8932DADB-D790-4A62-849A-4CB48D76E65A@ravnalaska.net>
 <mailman.34.1484590983.2442.python-list@python.org>
 <ee5mohFu7qfU1@mid.individual.net>
Message-ID: <o5kku3$foo$1@blaine.gmane.org>

Gregory Ewing wrote:

> Israel Brewster wrote:
>> The problem is that, from time to time, I can't get a connection, the
>> result being that cursor is None,
> 
> That's your problem right there -- you want a better-behaved
> version of psql_cursor().
> 
> def get_psql_cursor():
>     c = psql_cursor()
>     if c is None:
>        raise CantGetAConnectionError()
>     return c
> 
> with get_psql_cursor() as c:
>     ...

You still need to catch the error -- which leads to option (3) in my zoo, 
the only one that is actually usable. If one contextmanager cannot achieve 
what you want, use two:
 
$ cat conditional_context_raise.py
import sys
from contextlib import contextmanager

class NoConnection(Exception):
    pass

class Cursor:
    def execute(self, sql):
        print("EXECUTING", sql)

@contextmanager
def cursor():
    if "--fail" in sys.argv:
        raise NoConnection
    yield Cursor()

@contextmanager
def no_connection():
    try:
        yield
    except NoConnection:
        print("no connection")

with no_connection(), cursor() as cs:
    cs.execute("insert into...")
$ python3 conditional_context_raise.py
EXECUTING insert into...
$ python3 conditional_context_raise.py --fail
no connection

If you want to ignore the no-connection case use 
contextlib.suppress(NoConnection) instead of the custom no_connection() 
manager.



From larry at hastings.org  Tue Jan 17 03:40:39 2017
From: larry at hastings.org (Larry Hastings)
Date: Tue, 17 Jan 2017 00:40:39 -0800
Subject: [RELEASED] Python 3.4.6 and Python 3.5.3 are now available
Message-ID: <ed1b85b6-ac63-8973-9134-c8e7d968f386@hastings.org>


On behalf of the Python development community and the Python 3.4 and 
Python 3.5 release teams, I'm delighted to announce the availability of 
Python 3.4.6 and Python 3.5.3.

Python 3.4 is now in "security fixes only" mode.  This is the final 
stage of support for Python 3.4.  Python 3.4 now only receives security 
fixes, not bug fixes, and Python 3.4 releases are source code only--no 
more official binary installers will be produced.

Python 3.5 is still in active "bug fix" mode.  Python 3.5.3 contains 
many incremental improvements over Python 3.5.2.

There were literally no code changes between rc1 and final for either 
release.  The only change--apart from the necessary updates from "rc1" 
to final--was a single copyright notice update for one of the OS X 
".plist" property list files in 3.5.3 final.

You can find Python 3.5.3 here:

    https://www.python.org/downloads/release/python-353/

And you can find Python 3.4.6 here:

    https://www.python.org/downloads/release/python-346/



Best wishes,


//arry/


From antoon.pardon at rece.vub.ac.be  Tue Jan 17 04:37:04 2017
From: antoon.pardon at rece.vub.ac.be (Antoon Pardon)
Date: Tue, 17 Jan 2017 10:37:04 +0100
Subject: Emulating Final classes in Python
In-Reply-To: <587dc242$0$1601$c3e8da3$5496439d@news.astraweb.com>
References: <587dc242$0$1601$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <19450be4-a788-0e38-d70d-33d3edebc19e@rece.vub.ac.be>

Op 17-01-17 om 08:05 schreef Steven D'Aprano:
> I wish to emulate a "final" class using Python, similar to bool:
>
> py> class MyBool(bool):
> ...     pass
> ... 
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> TypeError: type 'bool' is not an acceptable base type
>
>
> It doesn't have to be absolutely bulletproof, but anyone wanting to subclass my 
> class should need to work for it, which hopefully will tell them that they're 
> doing something unsupported.
>
> Any hints?

I find those kind of classes annoying as hell and nobody has ever given me a good
reason for them. What good was it to change Lock from a factory function to a
class if you can't subclass the result anyway.

The result will probably be that users that would prefer to subclass your class
will monkey-patch it. Something like:

class MyLock:
    def __init__(self):
	self.lock = Lock()

    def __getattr__(self, attr):
	return getattr(self.lock, attr)


So I wonder what reasons do you have prefering that your users monkey-patch your
class instead of subclassing it?

-- 
Antoon Pardon



From python at lucidity.plus.com  Tue Jan 17 04:54:21 2017
From: python at lucidity.plus.com (Erik)
Date: Tue, 17 Jan 2017 09:54:21 +0000
Subject: Emulating Final classes in Python
In-Reply-To: <587dc242$0$1601$c3e8da3$5496439d@news.astraweb.com>
References: <587dc242$0$1601$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <e77ce439-34b6-1eb5-5a12-bc465147f51c@lucidity.plus.com>

Hi Steven,

On 17/01/17 07:05, Steven D'Aprano wrote:
> I wish to emulate a "final" class using Python, similar to bool:

[snip]

> It doesn't have to be absolutely bulletproof, but anyone wanting to subclass my
> class should need to work for it, which hopefully will tell them that they're
> doing something unsupported.

When someone brings up something like this you usually quote the 
"consenting adults" argument, so I'll throw it back at you - why not 
just add it to your documentation?

E.


From sg552 at hotmail.co.uk  Tue Jan 17 05:30:34 2017
From: sg552 at hotmail.co.uk (sg552 at hotmail.co.uk)
Date: Tue, 17 Jan 2017 02:30:34 -0800 (PST)
Subject: tokenize.untokenize adding line continuation characters
In-Reply-To: <587d859e$0$2804$c3e8da3$76491128@news.astraweb.com>
References: <dfc7f799-6d98-4413-94e7-df85c83e4d28@googlegroups.com>
 <587d859e$0$2804$c3e8da3$76491128@news.astraweb.com>
Message-ID: <883349aa-467c-450d-87e6-487099cfe5ab@googlegroups.com>

On Tuesday, January 17, 2017 at 2:47:03 AM UTC, Steven D'Aprano wrote:
> On Tuesday 17 January 2017 09:42, Rotwang wrote:
> 
> > Here's something odd I've found with the tokenize module: 
> [...]
> > Copypasted from iPython:
> 
> It's not impossible that iPython is doing something funny with the tokenize 
> module.

It happens outside iPython:

Python 3.4.3 (default, Oct 14 2015, 20:28:29) 
[GCC 4.8.4] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import io, tokenize
>>> tokenize.untokenize(tokenize.tokenize(io.BytesIO('if x:\n    y'.encode()).readline)).decode()
'if x:\n    y\\\n'


and also in Python 2:

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.
>>> import io, tokenize
>>> tokenize.untokenize(tokenize.generate_tokens(io.BytesIO('if x:\n    y').readline))
'if x:\n    y\\\n'


> Before reporting it as a bug, I recommend that you confirm that it also 
> occurs in the standard Python interpreter and isn't iPython specific.

Is this behaviour actually a bug, as opposed to a feature I don't understand?


From __peter__ at web.de  Tue Jan 17 06:10:37 2017
From: __peter__ at web.de (Peter Otten)
Date: Tue, 17 Jan 2017 12:10:37 +0100
Subject: tokenize.untokenize adding line continuation characters
References: <dfc7f799-6d98-4413-94e7-df85c83e4d28@googlegroups.com>
Message-ID: <o5ku38$vu8$1@blaine.gmane.org>

Rotwang wrote:

> Here's something odd I've found with the tokenize module: tokenizing 'if
> x:\n    y' and then untokenizing the result adds '\\\n' to the end.
> Attempting to tokenize the result again fails because of the backslash
> continuation with nothing other than a newline after it. On the other
> hand, if the original string ends with a newline then it works fine. Can
> anyone explain why this happens?

> I'm using Python 3.4.3 on Windows 8. Copypasted from iPython:

This looks like a bug...

$ python3.4 -c 'import tokenize as t, io; 
print(t.untokenize(t.tokenize(io.BytesIO(b"if x:\n  y").readline)))'
b'if x:\n  y\\\n'

...that is fixed now:

$ python3.6 -c 'import tokenize as t, io; 
print(t.untokenize(t.tokenize(io.BytesIO(b"if x:\n  y").readline)))'
b'if x:\n  y'

A quick search brought up multiple bug reports, among them

http://bugs.python.org/issue12691



From sg552 at hotmail.co.uk  Tue Jan 17 06:20:40 2017
From: sg552 at hotmail.co.uk (Rotwang)
Date: Tue, 17 Jan 2017 03:20:40 -0800 (PST)
Subject: tokenize.untokenize adding line continuation characters
In-Reply-To: <mailman.44.1484651475.2442.python-list@python.org>
References: <dfc7f799-6d98-4413-94e7-df85c83e4d28@googlegroups.com>
 <o5ku38$vu8$1@blaine.gmane.org>
 <mailman.44.1484651475.2442.python-list@python.org>
Message-ID: <320abf24-1062-42c7-b2e2-93ced2ab12c3@googlegroups.com>

On Tuesday, January 17, 2017 at 11:11:27 AM UTC, Peter Otten wrote:
> Rotwang wrote:
> 
> > Here's something odd I've found with the tokenize module: tokenizing 'if
> > x:\n    y' and then untokenizing the result adds '\\\n' to the end.
> > Attempting to tokenize the result again fails because of the backslash
> > continuation with nothing other than a newline after it. On the other
> > hand, if the original string ends with a newline then it works fine. Can
> > anyone explain why this happens?
> 
> > I'm using Python 3.4.3 on Windows 8. Copypasted from iPython:
> 
> This looks like a bug...
> 
> $ python3.4 -c 'import tokenize as t, io; 
> print(t.untokenize(t.tokenize(io.BytesIO(b"if x:\n  y").readline)))'
> b'if x:\n  y\\\n'
> 
> ...that is fixed now:
> 
> $ python3.6 -c 'import tokenize as t, io; 
> print(t.untokenize(t.tokenize(io.BytesIO(b"if x:\n  y").readline)))'
> b'if x:\n  y'
> 
> A quick search brought up multiple bug reports, among them
> 
> http://bugs.python.org/issue12691

Ah, thanks. I did search for bug reports before I started this thread but didn't find anything.


From rosuav at gmail.com  Tue Jan 17 11:57:51 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 18 Jan 2017 03:57:51 +1100
Subject: Python, asyncio, and systemd
Message-ID: <CAPTjJmqDkq4WqgRgC4vx=tkfPh=aK6XnFbyHSBYi=sM1+apPog@mail.gmail.com>

If I write a web server using asyncio (and the aiohttp package), I can
spin up the server with:

await loop.create_server(app.make_handler(), "0.0.0.0", 8080)

This works fine for a high port, but if I want to bind to port 80, I
need to either start as root and then drop privileges, or get given
the socket by someone else. With systemd, the latter is an option; you
configure a service unit and a socket unit, and when the service gets
started, it's given a bound listening socket as FD 3.

Most of the work is pretty straight-forward, but I ran into one
problem. The event loop's create_server() method calls a private
_start_serving method, which means I can't (or rather, I shouldn't)
just replicate create_server. This works, but it's naughty:

sock = socket.socket(fileno=3)

sock.setblocking(False)
loop._start_serving(app.make_handler(), sock)

What's the official way to say to asyncio "here's a listening socket,
start managing it for me"?

ChrisA


From ian.g.kelly at gmail.com  Tue Jan 17 12:06:53 2017
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Tue, 17 Jan 2017 10:06:53 -0700
Subject: Python, asyncio, and systemd
In-Reply-To: <CAPTjJmqDkq4WqgRgC4vx=tkfPh=aK6XnFbyHSBYi=sM1+apPog@mail.gmail.com>
References: <CAPTjJmqDkq4WqgRgC4vx=tkfPh=aK6XnFbyHSBYi=sM1+apPog@mail.gmail.com>
Message-ID: <CALwzid=eA00zt_dPAk=uXG3012GC+4MX4Gvbf0wGWWyCH5ah7A@mail.gmail.com>

On Tue, Jan 17, 2017 at 9:57 AM, Chris Angelico <rosuav at gmail.com> wrote:
> If I write a web server using asyncio (and the aiohttp package), I can
> spin up the server with:
>
> await loop.create_server(app.make_handler(), "0.0.0.0", 8080)
>
> This works fine for a high port, but if I want to bind to port 80, I
> need to either start as root and then drop privileges, or get given
> the socket by someone else. With systemd, the latter is an option; you
> configure a service unit and a socket unit, and when the service gets
> started, it's given a bound listening socket as FD 3.
>
> Most of the work is pretty straight-forward, but I ran into one
> problem. The event loop's create_server() method calls a private
> _start_serving method, which means I can't (or rather, I shouldn't)
> just replicate create_server. This works, but it's naughty:
>
> sock = socket.socket(fileno=3)
>
> sock.setblocking(False)
> loop._start_serving(app.make_handler(), sock)
>
> What's the official way to say to asyncio "here's a listening socket,
> start managing it for me"?

I haven't tried this but create_server takes a "sock" keyword-argument.

https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.AbstractEventLoop.create_server


From christian at python.org  Tue Jan 17 12:19:05 2017
From: christian at python.org (Christian Heimes)
Date: Tue, 17 Jan 2017 18:19:05 +0100
Subject: Python, asyncio, and systemd
In-Reply-To: <CAPTjJmqDkq4WqgRgC4vx=tkfPh=aK6XnFbyHSBYi=sM1+apPog@mail.gmail.com>
References: <CAPTjJmqDkq4WqgRgC4vx=tkfPh=aK6XnFbyHSBYi=sM1+apPog@mail.gmail.com>
Message-ID: <o5ljm4$ruk$1@blaine.gmane.org>

On 2017-01-17 17:57, Chris Angelico wrote:
> If I write a web server using asyncio (and the aiohttp package), I can
> spin up the server with:
> 
> await loop.create_server(app.make_handler(), "0.0.0.0", 8080)
> 
> This works fine for a high port, but if I want to bind to port 80, I
> need to either start as root and then drop privileges, or get given
> the socket by someone else. With systemd, the latter is an option; you
> configure a service unit and a socket unit, and when the service gets
> started, it's given a bound listening socket as FD 3.
> 
> Most of the work is pretty straight-forward, but I ran into one
> problem. The event loop's create_server() method calls a private
> _start_serving method, which means I can't (or rather, I shouldn't)
> just replicate create_server. This works, but it's naughty:
> 
> sock = socket.socket(fileno=3)
> 
> sock.setblocking(False)
> loop._start_serving(app.make_handler(), sock)
> 
> What's the official way to say to asyncio "here's a listening socket,
> start managing it for me"?

Hi Chris,

you might be interested in ticket [1], my module socketfromfd [2] and
some code I wrote for a HTTP server with socket activation [3]. The
latter does not use asyncio but shows how to use socket activation with
systemd. The blog posting [4] has some example code in case you don't
want to use systemd's Python module.

[1] https://bugs.python.org/issue28134
[2] https://github.com/tiran/socketfromfd
[3]
https://github.com/latchset/custodia/blob/master/custodia/httpd/server.py#L491
[4] http://0pointer.de/blog/projects/socket-activation.html

Christian



From rosuav at gmail.com  Tue Jan 17 13:03:04 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 18 Jan 2017 05:03:04 +1100
Subject: Python, asyncio, and systemd
In-Reply-To: <CALwzid=eA00zt_dPAk=uXG3012GC+4MX4Gvbf0wGWWyCH5ah7A@mail.gmail.com>
References: <CAPTjJmqDkq4WqgRgC4vx=tkfPh=aK6XnFbyHSBYi=sM1+apPog@mail.gmail.com>
 <CALwzid=eA00zt_dPAk=uXG3012GC+4MX4Gvbf0wGWWyCH5ah7A@mail.gmail.com>
Message-ID: <CAPTjJmoTJ98TvZJKLYydibtAJzY357b2CeX-DncUiv0GNpw1Xw@mail.gmail.com>

On Wed, Jan 18, 2017 at 4:06 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
>> What's the official way to say to asyncio "here's a listening socket,
>> start managing it for me"?
>
> I haven't tried this but create_server takes a "sock" keyword-argument.
>
> https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.AbstractEventLoop.create_server

Oh. Wow.

I am blind, or an idiot. That is exactly what I'm looking for.

My code now looks like this:

    if sock:
        srv = await loop.create_server(app.make_handler(), sock=sock)
    else:
        srv = await loop.create_server(app.make_handler(), "0.0.0.0", port)
        sock = srv.sockets[0]
    print("Listening on %s:%s" % sock.getsockname(), file=sys.stderr)

According to the docs, host and port must be unset (None) if sock is
given. It'd be nice if they could simply be ignored, in which case I
could just pass in all three parameters. (Yes, I'm forcing this to
IPv4 for this app, rather than using None or "::" to accept IPv6 as
well. If you're copying this code into your app, you should probably
accept IPv6, unless you know otherwise.)

But wow, I just completely didn't see that. I am incredible.

Thank you Ian!

ChrisA


From EIzydore at zoll.com  Tue Jan 17 13:23:58 2017
From: EIzydore at zoll.com (Earl Izydore)
Date: Tue, 17 Jan 2017 18:23:58 +0000
Subject: Python 3.6 Installation
Message-ID: <061F1A8C6BEA684BBC8CC0972537D3D024DBA9BB@AUSP07DAG0106.hostedmail.local>

I having problems installing Python 3.6.  I was using Python 2.7 successfully.

Today, I installed python-3.6.0.exe.  At the end of the installation I got a message saying the installation was successful.

When attempt to start Python, I get the following Application Error:
The application was unable to start correctly (0xc000007b).  Click OK to close the application.

I am using Windows 7 Professional, 64 bit.

Can you help?

Thanks

Earl Izydore
412-968-3333 ext. 14663
eizydore at zoll.com
[http://www.zoll.com/uploadedImages/images/emailsignaturelogo9_09.jpg]
An Asahi Kasei Group Company



From israel at ravnalaska.net  Tue Jan 17 13:54:08 2017
From: israel at ravnalaska.net (Israel Brewster)
Date: Tue, 17 Jan 2017 09:54:08 -0900
Subject: Error handling in context managers
In-Reply-To: <o5jhd9$dta$1@blaine.gmane.org>
References: <8932DADB-D790-4A62-849A-4CB48D76E65A@ravnalaska.net>
 <o5jhd9$dta$1@blaine.gmane.org>
Message-ID: <BFD4563B-FA20-4186-9285-279C71DEE516@ravnalaska.net>

On Jan 16, 2017, at 1:27 PM, Terry Reedy <tjreedy at udel.edu> wrote:
> 
> On 1/16/2017 1:06 PM, Israel Brewster wrote:
>> I generally use context managers for my SQL database connections, so I can just write code like:
>> 
>> with psql_cursor() as cursor:
>>    <do whatever>
>> 
>> And the context manager takes care of making a connection (or getting a connection from a pool, more likely), and cleaning up after the fact (such as putting the connection back in the pool), even if something goes wrong. Simple, elegant, and works well.
>> 
>> The problem is that, from time to time, I can't get a connection, the result being that cursor is None,
> 
> This would be like open('bad file') returning None instead of raising FileNotFoundError.
> 
>> and attempting to use it results in an AttributeError.
> 
> Just as None.read would.
> 
> Actually, I have to wonder about your claim.  The with statement would look for cursor.__enter__ and then cursor.__exit__, and None does not have those methods.  In other words, the expression following 'with' must evaluate to a context manager and None is not a context manager.
> 
> >>> with None: pass
> 
> Traceback (most recent call last):
>  File "<pyshell#3>", line 1, in <module>
>    with None: pass
> AttributeError: __enter__
> 
> Is psql_cursor() returning a fake None object with __enter__ and __exit__ methods?

No, the *context manager*, which I call in the with *does* have __enter__ and __exit__ methods. It's just that the __enter__ method returns None when it can't get a connection. So the expression following with *does* evaluate to a context manager, but the expression following as evaluates to None.

-----------------------------------------------
Israel Brewster
Systems Analyst II
Ravn Alaska
5245 Airport Industrial Rd
Fairbanks, AK 99709
(907) 450-7293
-----------------------------------------------

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



From israel at ravnalaska.net  Tue Jan 17 13:55:35 2017
From: israel at ravnalaska.net (Israel Brewster)
Date: Tue, 17 Jan 2017 09:55:35 -0900
Subject: Error handling in context managers
In-Reply-To: <ee5mohFu7qfU1@mid.individual.net>
References: <8932DADB-D790-4A62-849A-4CB48D76E65A@ravnalaska.net>
 <mailman.34.1484590983.2442.python-list@python.org>
 <ee5mohFu7qfU1@mid.individual.net>
Message-ID: <76F831C9-20B9-4B4A-8557-0AB1C10C2EF6@ravnalaska.net>

On Jan 16, 2017, at 8:01 PM, Gregory Ewing <greg.ewing at canterbury.ac.nz> wrote:
> 
> Israel Brewster wrote:
>> The problem is that, from time to time, I can't get a connection, the result
>> being that cursor is None,
> 
> That's your problem right there -- you want a better-behaved
> version of psql_cursor().
> 
> def get_psql_cursor():
>   c = psql_cursor()
>   if c is None:
>      raise CantGetAConnectionError()
>   return c
> 
> with get_psql_cursor() as c:
>   ...
> 

Ok, fair enough. So I get a better exception, raised at the proper time. This is, in fact, better - but doesn't actually change how I would *handle* the exception :-)
-----------------------------------------------
Israel Brewster
Systems Analyst II
Ravn Alaska
5245 Airport Industrial Rd
Fairbanks, AK 99709
(907) 450-7293
-----------------------------------------------

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



From israel at ravnalaska.net  Tue Jan 17 13:59:16 2017
From: israel at ravnalaska.net (Israel Brewster)
Date: Tue, 17 Jan 2017 09:59:16 -0900
Subject: Error handling in context managers
In-Reply-To: <o5kku3$foo$1@blaine.gmane.org>
References: <8932DADB-D790-4A62-849A-4CB48D76E65A@ravnalaska.net>
 <mailman.34.1484590983.2442.python-list@python.org>
 <ee5mohFu7qfU1@mid.individual.net> <o5kku3$foo$1@blaine.gmane.org>
Message-ID: <4A29C931-8241-4175-ACE0-B472910DD701@ravnalaska.net>

On Jan 16, 2017, at 11:34 PM, Peter Otten <__peter__ at web.de> wrote:
> 
> Gregory Ewing wrote:
> 
>> Israel Brewster wrote:
>>> The problem is that, from time to time, I can't get a connection, the
>>> result being that cursor is None,
>> 
>> That's your problem right there -- you want a better-behaved
>> version of psql_cursor().
>> 
>> def get_psql_cursor():
>>    c = psql_cursor()
>>    if c is None:
>>       raise CantGetAConnectionError()
>>    return c
>> 
>> with get_psql_cursor() as c:
>>    ...
> 
> You still need to catch the error -- which leads to option (3) in my zoo, 
> the only one that is actually usable. If one contextmanager cannot achieve 
> what you want, use two:
> 
> $ cat conditional_context_raise.py
> import sys
> from contextlib import contextmanager
> 
> class NoConnection(Exception):
>    pass
> 
> class Cursor:
>    def execute(self, sql):
>        print("EXECUTING", sql)
> 
> @contextmanager
> def cursor():
>    if "--fail" in sys.argv:
>        raise NoConnection
>    yield Cursor()
> 
> @contextmanager
> def no_connection():
>    try:
>        yield
>    except NoConnection:
>        print("no connection")
> 
> with no_connection(), cursor() as cs:
>    cs.execute("insert into...")
> $ python3 conditional_context_raise.py
> EXECUTING insert into...
> $ python3 conditional_context_raise.py --fail
> no connection
> 
> If you want to ignore the no-connection case use 
> contextlib.suppress(NoConnection) instead of the custom no_connection() 
> manager.

Fun :-) I'll have to play around with that. Thanks! :-)

-----------------------------------------------
Israel Brewster
Systems Analyst II
Ravn Alaska
5245 Airport Industrial Rd
Fairbanks, AK 99709
(907) 450-7293
-----------------------------------------------
> 
> -- 
> https://mail.python.org/mailman/listinfo/python-list



From ethan at stoneleaf.us  Tue Jan 17 14:14:13 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 17 Jan 2017 11:14:13 -0800
Subject: Emulating Final classes in Python
In-Reply-To: <587dc8a8$0$1589$c3e8da3$5496439d@news.astraweb.com>
References: <587dc242$0$1601$c3e8da3$5496439d@news.astraweb.com>
 <587dc8a8$0$1589$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <587E6D05.8080603@stoneleaf.us>

On 01/16/2017 11:32 PM, Steven D'Aprano wrote:
> On Tuesday 17 January 2017 18:05, Steven D'Aprano wrote:
>
>> I wish to emulate a "final" class using Python, similar to bool:
>
> I may have a solution: here's a singleton (so more like None than bools) where
> instantiating the class returns the singleton, and subclassing the class fails:
>
> class DoneMeta(type):
>      _final = None
>      def __new__(meta, name, bases, ns):
>          if meta._final is None:
>              meta._final = cls = super().__new__(meta, name, bases, ns)
>              return cls
>          elif meta._final in bases:  # Not sure this check is needed.
>              raise TypeError('base class is final and cannot be subclassed')

This will make DoneMeta a one-shot, meaning you'll have to make more DoneMeta's if you need more than one unsubclassable class.

> class DoneType(metaclass=DoneMeta):
>      __slots__ = ()
>      _instance = None
>      def __new__(cls):
>          if cls._instance is None:
>              cls._instance = inst = super().__new__(cls)
>              return inst
>          return cls._instance
>      def __repr__(self):
>          return '<DONE>'

And this has to do with single instances, which is not what you asked about.

Here's some sample code that creates a Final class; any class that subclasses from it cannot be further subclassed:

-- 8< ------------------------------------------------------------

Final = None

class FinalMeta(type):

     def __new__(metacls, cls, bases, clsdict):
         print('-' * 50)
         print('class: ', cls)
         print('bases: ', bases)
         if Final is not None:
             for base in bases:
                 if base is not Final and  issubclass(base, Final):
                     print('should raise')
         print('-' * 50)
         return type.__new__(metacls, cls, bases, clsdict)

class Final(metaclass=FinalMeta):
     pass

class One(Final):
     pass

class Two(One):
     pass

class Three(Two):
     pass

class Ten(Final):
     pass

-- 8< ------------------------------------------------------------

Change the "should raise" to a raise, remove the other print()s, and away you go.

Should work in any Python 3.

--
~Ethan~


From tjreedy at udel.edu  Tue Jan 17 17:31:15 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Tue, 17 Jan 2017 17:31:15 -0500
Subject: Python 3.6 Installation
In-Reply-To: <061F1A8C6BEA684BBC8CC0972537D3D024DBA9BB@AUSP07DAG0106.hostedmail.local>
References: <061F1A8C6BEA684BBC8CC0972537D3D024DBA9BB@AUSP07DAG0106.hostedmail.local>
Message-ID: <o5m5vg$jhf$1@blaine.gmane.org>

On 1/17/2017 1:23 PM, Earl Izydore wrote:
> I having problems installing Python 3.6.  I was using Python 2.7
> successfully.
>
> Today, I installed python-3.6.0.exe.

Which binary? from where?

> At the end of the installation I got a message saying the
> installation was successful.
>
> When attempt to start Python, I get the following Application Error:
> The application was unable to start correctly (0xc000007b).  Click OK
> to close the application.

Searching the web for 0xc000007b gets many hits and suggestions.  For 
python, searching stackoverflow.con is probably better.

https://stackoverflow.com/questions/20650596/cannot-open-python-error-0xc000007b

is only one of the hits.

> I am using Windows 7 Professional, 64 bit.

-- 
Terry Jan Reedy



From steve+python at pearwood.info  Tue Jan 17 18:25:36 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 18 Jan 2017 10:25:36 +1100
Subject: Emulating Final classes in Python
References: <587dc242$0$1601$c3e8da3$5496439d@news.astraweb.com>
 <e77ce439-34b6-1eb5-5a12-bc465147f51c@lucidity.plus.com>
 <mailman.43.1484646869.2442.python-list@python.org>
Message-ID: <587ea7f2$0$22141$c3e8da3$5496439d@news.astraweb.com>

On Tue, 17 Jan 2017 08:54 pm, Erik wrote:

> Hi Steven,
> 
> On 17/01/17 07:05, Steven D'Aprano wrote:
>> I wish to emulate a "final" class using Python, similar to bool:
> 
> [snip]
> 
>> It doesn't have to be absolutely bulletproof, but anyone wanting to
>> subclass my class should need to work for it, which hopefully will tell
>> them that they're doing something unsupported.
> 
> When someone brings up something like this you usually quote the
> "consenting adults" argument, so I'll throw it back at you - why not
> just add it to your documentation?


A very good question :-)

Why am I doing this? Part of the answer is simply because I can. I want to
see how far I can go to lock down the class in pure Python code.




-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From steve+python at pearwood.info  Tue Jan 17 18:51:03 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 18 Jan 2017 10:51:03 +1100
Subject: Emulating Final classes in Python
References: <587dc242$0$1601$c3e8da3$5496439d@news.astraweb.com>
 <587dc8a8$0$1589$c3e8da3$5496439d@news.astraweb.com>
 <587E6D05.8080603@stoneleaf.us>
 <mailman.53.1484680423.2442.python-list@python.org>
Message-ID: <587eade9$0$1617$c3e8da3$5496439d@news.astraweb.com>

On Wed, 18 Jan 2017 06:14 am, Ethan Furman wrote:

> On 01/16/2017 11:32 PM, Steven D'Aprano wrote:
>> On Tuesday 17 January 2017 18:05, Steven D'Aprano wrote:
>>
>>> I wish to emulate a "final" class using Python, similar to bool:
>>
>> I may have a solution: here's a singleton (so more like None than bools)
>> where instantiating the class returns the singleton, and subclassing the
>> class fails:
>>
>> class DoneMeta(type):
>>      _final = None
>>      def __new__(meta, name, bases, ns):
>>          if meta._final is None:
>>              meta._final = cls = super().__new__(meta, name, bases, ns)
>>              return cls
>>          elif meta._final in bases:  # Not sure this check is needed.
>>              raise TypeError('base class is final and cannot be
>>              subclassed')
> 
> This will make DoneMeta a one-shot, meaning you'll have to make more
> DoneMeta's if you need more than one unsubclassable class.

For my purposes, that's enough -- I only have one object that I actually
need, something which is like None or Ellipsis or NotImplemented, just a
unique and featureless point-particle with no state or behaviour (apart
from a neat repr).

Yes yes, it's that damn singleton design (anti-)pattern again :-)

It's a bit ... something ... that to make a single stateless, behaviourless
instance I need a class and a metaclass, but that's Python for you.

As an alternative, I may use a single Enum, and delete the class object
after I've extracted the enumeration:

from enum import Enum

class DoneType(Enum):
    DONE = 'Done'

DONE = DoneType(DONE)
del DoneType


Although enumerations have more behaviour than I need, maybe this is close
enough that I don't care.


>> class DoneType(metaclass=DoneMeta):
>>      __slots__ = ()
>>      _instance = None
>>      def __new__(cls):
>>          if cls._instance is None:
>>              cls._instance = inst = super().__new__(cls)
>>              return inst
>>          return cls._instance
>>      def __repr__(self):
>>          return '<DONE>'
> 
> And this has to do with single instances, which is not what you asked
> about.

Very observant of you :-)



> Here's some sample code that creates a Final class; any class that
> subclasses from it cannot be further subclassed:

Thanks.



-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From torriem at gmail.com  Tue Jan 17 20:30:36 2017
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 17 Jan 2017 18:30:36 -0700
Subject: Python 3.6 Installation
In-Reply-To: <o5m5vg$jhf$1@blaine.gmane.org>
References: <061F1A8C6BEA684BBC8CC0972537D3D024DBA9BB@AUSP07DAG0106.hostedmail.local>
 <o5m5vg$jhf$1@blaine.gmane.org>
Message-ID: <4ef0f5b2-01f0-72ae-b6e7-add88d5bacc0@gmail.com>

On 01/17/2017 03:31 PM, Terry Reedy wrote:
> On 1/17/2017 1:23 PM, Earl Izydore wrote:
>> I having problems installing Python 3.6.  I was using Python 2.7
>> successfully.
>>
>> Today, I installed python-3.6.0.exe.
> 
> Which binary? from where?
> 
>> At the end of the installation I got a message saying the
>> installation was successful.
>>
>> When attempt to start Python, I get the following Application Error:
>> The application was unable to start correctly (0xc000007b).  Click OK
>> to close the application.
> 
> Searching the web for 0xc000007b gets many hits and suggestions.  For 
> python, searching stackoverflow.con is probably better.
> 
> https://stackoverflow.com/questions/20650596/cannot-open-python-error-0xc000007b
> 
> is only one of the hits.
> 
>> I am using Windows 7 Professional, 64 bit.

Yes googling error messages is a good idea. However the SO link seems to
describe this problem as a missing DLL, probably the VS 2015 runtime
redistributable library.  If this is the problem, why isn't Python's
installer bundling the runtime for optional install?  Many other
installers do this.  Judging by the frequency of posts like this one to
this list, it's a problem that affects more than a few users.

Anyway, it seems like this kind of runtime error is cropping up more and
more for folks.


From steve+comp.lang.python at pearwood.info  Tue Jan 17 21:10:41 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 18 Jan 2017 13:10:41 +1100
Subject: Emulating Final classes in Python
References: <587dc242$0$1601$c3e8da3$5496439d@news.astraweb.com>
 <19450be4-a788-0e38-d70d-33d3edebc19e@rece.vub.ac.be>
 <mailman.42.1484645924.2442.python-list@python.org>
Message-ID: <587ecea3$0$1522$c3e8da3$5496439d@news.astraweb.com>

On Tuesday 17 January 2017 20:37, Antoon Pardon wrote:

> Op 17-01-17 om 08:05 schreef Steven D'Aprano:
>> I wish to emulate a "final" class using Python, similar to bool:
>>
>> py> class MyBool(bool):
>> ...     pass
>> ...
>> Traceback (most recent call last):
>>   File "<stdin>", line 1, in <module>
>> TypeError: type 'bool' is not an acceptable base type
[...]
> I find those kind of classes annoying as hell and nobody has ever given me a
> good reason for them. What good was it to change Lock from a factory function
> to a class if you can't subclass the result anyway.

I'm not sure which Lock class you're referring to.


> The result will probably be that users that would prefer to subclass your
> class will monkey-patch it. Something like:
> 
> class MyLock:
>     def __init__(self):
>         self.lock = Lock()
> 
>     def __getattr__(self, attr):
>         return getattr(self.lock, attr)

That technique is called "delegation", or sometimes "composition".


> So I wonder what reasons do you have prefering that your users monkey-patch
> your class instead of subclassing it?

Since my class provides no useful behaviour, I don't think anyone will 
seriously have any reason to subclass it.

Python has at least three singleton instances which are used purely as abstract 
symbols: they have no state, and very little behaviour besides a nice repr. 
They are None, NotImplemented and Ellipsis. I'm effectively trying to make my 
own abstract symbol.

But it's mostly a learning exercise.



-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From steve+comp.lang.python at pearwood.info  Tue Jan 17 21:12:22 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 18 Jan 2017 13:12:22 +1100
Subject: Python 3.6 Installation
References: <061F1A8C6BEA684BBC8CC0972537D3D024DBA9BB@AUSP07DAG0106.hostedmail.local>
 <o5m5vg$jhf$1@blaine.gmane.org>
 <4ef0f5b2-01f0-72ae-b6e7-add88d5bacc0@gmail.com>
 <mailman.0.1484703048.9761.python-list@python.org>
Message-ID: <587ecf06$0$1522$c3e8da3$5496439d@news.astraweb.com>

On Wednesday 18 January 2017 12:30, Michael Torrie wrote:

> Yes googling error messages is a good idea. However the SO link seems to
> describe this problem as a missing DLL, probably the VS 2015 runtime
> redistributable library.  If this is the problem, why isn't Python's
> installer bundling the runtime for optional install?  Many other
> installers do this.  Judging by the frequency of posts like this one to
> this list, it's a problem that affects more than a few users.
> 
> Anyway, it seems like this kind of runtime error is cropping up more and
> more for folks.

Perhaps some Python-on-Windows user who cares about this issue should raise it 
on the bug tracker as a feature request.




-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From torriem at gmail.com  Tue Jan 17 23:32:46 2017
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 17 Jan 2017 21:32:46 -0700
Subject: Python 3.6 Installation
In-Reply-To: <587ecf06$0$1522$c3e8da3$5496439d@news.astraweb.com>
References: <061F1A8C6BEA684BBC8CC0972537D3D024DBA9BB@AUSP07DAG0106.hostedmail.local>
 <o5m5vg$jhf$1@blaine.gmane.org>
 <4ef0f5b2-01f0-72ae-b6e7-add88d5bacc0@gmail.com>
 <mailman.0.1484703048.9761.python-list@python.org>
 <587ecf06$0$1522$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <5dd005ca-1022-0521-d70c-b8f007477663@gmail.com>

On 01/17/2017 07:12 PM, Steven D'Aprano wrote:
> On Wednesday 18 January 2017 12:30, Michael Torrie wrote:
> 
>> Yes googling error messages is a good idea. However the SO link seems to
>> describe this problem as a missing DLL, probably the VS 2015 runtime
>> redistributable library.  If this is the problem, why isn't Python's
>> installer bundling the runtime for optional install?  Many other
>> installers do this.  Judging by the frequency of posts like this one to
>> this list, it's a problem that affects more than a few users.
>>
>> Anyway, it seems like this kind of runtime error is cropping up more and
>> more for folks.
> 
> Perhaps some Python-on-Windows user who cares about this issue should raise it 
> on the bug tracker as a feature request.

I did a quick search of the issue tracker and now I'm confused.
Apparently the installer does bundle the runtime with Python.  And if
Python is compiled against this new MS universal runtime that is
supposed to be in all supported versions of windows (from windows
update) why is Visual Studio 2015 redistributable required, as per the
SO link Terry linked to?

http://bugs.python.org/issue28592 -- Erik mentions that the runtime is
bundled with the installer, but probably shouldn't be since it's a
windows update thing now...


From ethan at stoneleaf.us  Tue Jan 17 23:42:28 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 17 Jan 2017 20:42:28 -0800
Subject: Emulating Final classes in Python
In-Reply-To: <19450be4-a788-0e38-d70d-33d3edebc19e@rece.vub.ac.be>
References: <587dc242$0$1601$c3e8da3$5496439d@news.astraweb.com>
 <19450be4-a788-0e38-d70d-33d3edebc19e@rece.vub.ac.be>
Message-ID: <587EF234.90502@stoneleaf.us>

On 01/17/2017 01:37 AM, Antoon Pardon wrote:
> Op 17-01-17 om 08:05 schreef Steven D'Aprano:

>> I wish to emulate a "final" class using Python, similar to bool:
>>
>> py> class MyBool(bool):
>> ...     pass
>> ...
>> Traceback (most recent call last):
>>    File "<stdin>", line 1, in <module>
>> TypeError: type 'bool' is not an acceptable base type
>
> I find those kind of classes annoying as hell and nobody has ever given me a good
> reason for them.

Subclassing an Enum that has members can be confusing -- subclassed members pass isinstance checks but fail to show up in the parent class' iteration.

Subclassing a new data type, such as one with Yes, No, and Maybe, with lots of code dealing explicitly with those three singletons, would be confusing if not outright broken.

Both those cases are good candidates for disallowing subclassing.

--
~Ethan~


From tjreedy at udel.edu  Wed Jan 18 01:23:34 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Wed, 18 Jan 2017 01:23:34 -0500
Subject: Python 3.6 Installation
In-Reply-To: <5dd005ca-1022-0521-d70c-b8f007477663@gmail.com>
References: <061F1A8C6BEA684BBC8CC0972537D3D024DBA9BB@AUSP07DAG0106.hostedmail.local>
 <o5m5vg$jhf$1@blaine.gmane.org>
 <4ef0f5b2-01f0-72ae-b6e7-add88d5bacc0@gmail.com>
 <mailman.0.1484703048.9761.python-list@python.org>
 <587ecf06$0$1522$c3e8da3$5496439d@news.astraweb.com>
 <5dd005ca-1022-0521-d70c-b8f007477663@gmail.com>
Message-ID: <o5n1l2$umt$1@blaine.gmane.org>

On 1/17/2017 11:32 PM, Michael Torrie wrote:
> On 01/17/2017 07:12 PM, Steven D'Aprano wrote:
>> On Wednesday 18 January 2017 12:30, Michael Torrie wrote:
>>
>>> Yes googling error messages is a good idea. However the SO link seems to
>>> describe this problem as a missing DLL, probably the VS 2015 runtime
>>> redistributable library.  If this is the problem, why isn't Python's
>>> installer bundling the runtime for optional install?  Many other
>>> installers do this.  Judging by the frequency of posts like this one to
>>> this list, it's a problem that affects more than a few users.
>>>
>>> Anyway, it seems like this kind of runtime error is cropping up more and
>>> more for folks.
>>
>> Perhaps some Python-on-Windows user who cares about this issue should raise it
>> on the bug tracker as a feature request.
>
> I did a quick search of the issue tracker and now I'm confused.
> Apparently the installer does bundle the runtime with Python.  And if
> Python is compiled against this new MS universal runtime that is
> supposed to be in all supported versions of windows (from windows
> update)

Not everyone has run Windows update since the current runtime was released.

  why is Visual Studio 2015 redistributable required, as per the
> SO link Terry linked to?
>
> http://bugs.python.org/issue28592 -- Erik mentions that the runtime is
> bundled with the installer, but probably shouldn't be since it's a
> windows update thing now...
>


-- 
Terry Jan Reedy



From steve+comp.lang.python at pearwood.info  Wed Jan 18 02:05:33 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 18 Jan 2017 18:05:33 +1100
Subject: Emulating Final classes in Python
References: <587dc242$0$1601$c3e8da3$5496439d@news.astraweb.com>
 <19450be4-a788-0e38-d70d-33d3edebc19e@rece.vub.ac.be>
 <587EF234.90502@stoneleaf.us>
 <mailman.2.1484714523.9761.python-list@python.org>
Message-ID: <587f13c0$0$1590$c3e8da3$5496439d@news.astraweb.com>

On Wednesday 18 January 2017 15:42, Ethan Furman wrote:

[...]
> Both those cases are good candidates for disallowing subclassing.

I've given a metaclass that disallows subclassing:

class MyClass(MyParent, metaclass=FinalMeta):
    ...


Ethan took that one step further by giving a class you inherit from to disallow 
subclassing:

class MyClass(MyParent, Final):
    ...


Could we solve this problem with a decorator?


@final
class MyClass(MyParent):
    ...


Without needing to add any special magic to MyParent or MyClass, apart from the 
decorator, can we make MyClass final? That would (in principle) allow us to 
make a subclass, and *then* set the class final so that no more subclasses 
could be made.


I thought that the decorator could simply set the class' metaclass:

def final(cls):
    if cls.__class__ is type:
        cls.__class__ = Meta
        return cls
    raise TypeErrror('Possible metaclass conflict')


but that's disallowed. Any ideas?



-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From cs at zip.com.au  Wed Jan 18 05:49:31 2017
From: cs at zip.com.au (Cameron Simpson)
Date: Wed, 18 Jan 2017 21:49:31 +1100
Subject: trouble with cmd.Cmd and prompting
In-Reply-To: <20170104012018.GA72609@cskk.homeip.net>
References: <20170104012018.GA72609@cskk.homeip.net>
Message-ID: <20170118104931.GA98212@cskk.homeip.net>

On 04Jan2017 12:20, Cameron Simpson <cs at zip.com.au> wrote:
>I will try to get a minimal example others can run.

Well I've made some time for this, and it seems to be an interaction with my 
python3, the "input" builtin, and readline. Cmd.cmdloop behaves fine if I turn 
off the .raw_input attribute, and I can reproduce the issue without the cmd 
module.

Test code:

  import readline
  line = input("F> ")
  print("gap")
  line = input("G> ")

Results on a terminal:

  [~]fleet*2> python3 foo.py
  F> a
  F> gap
  n
  G> %                                                                                    
  [~]fleet*>

That "%" is an artifact of no final newline after the "G> ".

If I comment out the import of readline it looks like this:

  G> %                                                                                    
  [~]fleet*> python3 foo.py
  F> a
  gap
  G> b
  [~]fleet*> 

as one would expect. Ignoring my shell prompts, the contents of a typescript 
show:

  python3 foo.py^M
  F> a^M
  F> gap^M
  b^M
  G>

Those "^M"s are carriage returns. I kind of suspect the second "F> " is 
readline doing some kind of redraw. I am baffled by the lack of initial "G> " 
prompt; that "G> " above appears to be the secondary issue, after I've pressed 
return for the "b" line.

This is on a Mac, so I've no strace command to hand. I've also got all manner 
of potential special stuff (readline library from MacPorts, etc). I'll keep 
stripping stuff back...

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


From __peter__ at web.de  Wed Jan 18 07:47:47 2017
From: __peter__ at web.de (Peter Otten)
Date: Wed, 18 Jan 2017 13:47:47 +0100
Subject: trouble with cmd.Cmd and prompting
References: <20170104012018.GA72609@cskk.homeip.net>
 <20170118104931.GA98212@cskk.homeip.net>
Message-ID: <o5no5i$r0g$1@blaine.gmane.org>

Cameron Simpson wrote:

> On 04Jan2017 12:20, Cameron Simpson <cs at zip.com.au> wrote:
>>I will try to get a minimal example others can run.
> 
> Well I've made some time for this, and it seems to be an interaction with
> my python3, the "input" builtin, and readline. Cmd.cmdloop behaves fine if
> I turn off the .raw_input attribute, and I can reproduce the issue without
> the cmd module.
> 
> Test code:
> 
>   import readline
>   line = input("F> ")
>   print("gap")
>   line = input("G> ")

If readline is not used input() writes its prompt to stderr. I don't have a 
Mac, but it might be worthwhile to investigate what goes where. For 
comparison here's what happens on my Linux system:

$ cat tmp.py
import sys

if "-r" in sys.argv:
    import readline

print(
    "uses readline" if "readline" in sys.modules
    else "no readline"
)
line = input("F> ")
print("gap")
line = input("G> ")

$ python3 tmp.py
no readline
F> alpha
gap
G> beta

$ python3 tmp.py 2>/dev/null
no readline
alpha
gap
beta

$ python3 tmp.py -r 2>/dev/null
uses readline
F> alpha
gap
G> beta
 




From alister.ware at ntlworld.com  Wed Jan 18 08:43:10 2017
From: alister.ware at ntlworld.com (alister)
Date: Wed, 18 Jan 2017 13:43:10 GMT
Subject: Emulating Final classes in Python
References: <587dc242$0$1601$c3e8da3$5496439d@news.astraweb.com>
 <19450be4-a788-0e38-d70d-33d3edebc19e@rece.vub.ac.be>
 <mailman.42.1484645924.2442.python-list@python.org>
 <587ecea3$0$1522$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <OhKfA.17226$9Y7.2231@fx27.am4>

On Wed, 18 Jan 2017 13:10:41 +1100, Steven D'Aprano wrote:

> On Tuesday 17 January 2017 20:37, Antoon Pardon wrote:
> 
>> Op 17-01-17 om 08:05 schreef Steven D'Aprano:
>>> I wish to emulate a "final" class using Python, similar to bool:
>>>
>>> py> class MyBool(bool):
>>> ...     pass ...
>>> Traceback (most recent call last):
>>>   File "<stdin>", line 1, in <module>
>>> TypeError: type 'bool' is not an acceptable base type
> [...]
>> I find those kind of classes annoying as hell and nobody has ever given
>> me a good reason for them. What good was it to change Lock from a
>> factory function to a class if you can't subclass the result anyway.
> 
> I'm not sure which Lock class you're referring to.
> 
> 
>> The result will probably be that users that would prefer to subclass
>> your class will monkey-patch it. Something like:
>> 
>> class MyLock:
>>     def __init__(self):
>>         self.lock = Lock()
>> 
>>     def __getattr__(self, attr):
>>         return getattr(self.lock, attr)
> 
> That technique is called "delegation", or sometimes "composition".
> 
> 
>> So I wonder what reasons do you have prefering that your users
>> monkey-patch your class instead of subclassing it?
> 
> Since my class provides no useful behaviour, I don't think anyone will
> seriously have any reason to subclass it.

if it provides "No Usefull behaviour" why does it even exist
what useless behaviour does it provide? :-)

(no mater how pointless there is always someone how will find a use, I 
even know someone who successfully sold a box of paper shredding on ebay!)

> 
> Python has at least three singleton instances which are used purely as
> abstract symbols: they have no state, and very little behaviour besides
> a nice repr. They are None, NotImplemented and Ellipsis. I'm effectively
> trying to make my own abstract symbol.
> 
> But it's mostly a learning exercise.





-- 
Good programmers treat Microsoft products as damage and route
around them.

   -- From a Slashdot.org post


From ethan at stoneleaf.us  Wed Jan 18 11:24:26 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Wed, 18 Jan 2017 08:24:26 -0800
Subject: Emulating Final classes in Python
In-Reply-To: <587f13c0$0$1590$c3e8da3$5496439d@news.astraweb.com>
References: <587dc242$0$1601$c3e8da3$5496439d@news.astraweb.com>
 <19450be4-a788-0e38-d70d-33d3edebc19e@rece.vub.ac.be>
 <587EF234.90502@stoneleaf.us>
 <mailman.2.1484714523.9761.python-list@python.org>
 <587f13c0$0$1590$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <587F96BA.8070707@stoneleaf.us>

On 01/17/2017 11:05 PM, Steven D'Aprano wrote:

> I've given a metaclass that disallows subclassing:
>
> class MyClass(MyParent, metaclass=FinalMeta):
>      ...
>
>
> Ethan took that one step further by giving a class you inherit from to disallow
> subclassing:
>
> class MyClass(MyParent, Final):
>      ...
>
>
> Could we solve this problem with a decorator?
>
>
> @final
> class MyClass(MyParent):
>      ...
>
>
> Without needing to add any special magic to MyParent or MyClass, apart from the
> decorator, can we make MyClass final? That would (in principle) allow us to
> make a subclass, and *then* set the class final so that no more subclasses
> could be made.
>
>
> I thought that the decorator could simply set the class' metaclass:
>
> def final(cls):
>      if cls.__class__ is type:
>          cls.__class__ = Meta
>          return cls
>      raise TypeErrror('Possible metaclass conflict')
>
>
> but that's disallowed. Any ideas?

You still need to have the FinalMeta type and Final class available, but to use a decorator you'll need to scavenge the bits from the old class to make a new class of the same name and return that:

def final(cls):
     new_cls = Meta(cls.__name__, (Final, )+cls.__bases__, dict(cls.__dict__))
     return new_cls

Not sure if more is needed to handle __slots__, but this should get us started.

--
~Ethan~


From eryksun at gmail.com  Wed Jan 18 12:59:05 2017
From: eryksun at gmail.com (eryk sun)
Date: Wed, 18 Jan 2017 17:59:05 +0000
Subject: Python 3.6 Installation
In-Reply-To: <o5n1l2$umt$1@blaine.gmane.org>
References: <061F1A8C6BEA684BBC8CC0972537D3D024DBA9BB@AUSP07DAG0106.hostedmail.local>
 <o5m5vg$jhf$1@blaine.gmane.org>
 <4ef0f5b2-01f0-72ae-b6e7-add88d5bacc0@gmail.com>
 <mailman.0.1484703048.9761.python-list@python.org>
 <587ecf06$0$1522$c3e8da3$5496439d@news.astraweb.com>
 <5dd005ca-1022-0521-d70c-b8f007477663@gmail.com>
 <o5n1l2$umt$1@blaine.gmane.org>
Message-ID: <CACL+1asG-CEveF9rj4vV=WDjvBDC-KW_B_QQZpioXV4bgo0j8w@mail.gmail.com>

On Wed, Jan 18, 2017 at 6:23 AM, Terry Reedy <tjreedy at udel.edu> wrote:
> Not everyone has run Windows update since the current runtime was released.

Python's installer tries (and sometimes fails) to install the
KB2999226 update, which installs an old version of the Universal CRT.
Some installers instead bundle the VC++ redistributable, which
includes KB2999226, but that would be overkill for CPython. I thought
we could phase this out in 3.6 to instead require an up-to-date OS. If
people need offline updates, as opposed to using Windows update, it's
better to get the most recent version directly from Microsoft,
KB3118401 [1]. Steve Dower disagreed, and that's the end of it.

As to the loader returning STATUS_INVALID_IMAGE_FORMAT (0xC000007B), I
would run the executable/script under a debugger such as WinDbg or
cdb, with loader snaps enabled via gflags. Find the troublesome
DLL(s), and manually resolve the problem.

[1]: https://support.microsoft.com/en-us/kb/3118401


From smith at smith.it  Wed Jan 18 14:51:05 2017
From: smith at smith.it (Smith)
Date: Wed, 18 Jan 2017 20:51:05 +0100
Subject: sorting list python
Message-ID: <o5ogv8$13mj$1@gioia.aioe.org>

Hi all,
could you do better?
Thank you in advance

link code:
https://repl.it/FMin/8


From __peter__ at web.de  Wed Jan 18 15:20:17 2017
From: __peter__ at web.de (Peter Otten)
Date: Wed, 18 Jan 2017 21:20:17 +0100
Subject: sorting list python
References: <o5ogv8$13mj$1@gioia.aioe.org>
Message-ID: <o5oilu$n9k$1@blaine.gmane.org>

Smith wrote:

> Hi all,
> could you do better?
> Thank you in advance
> 
> link code:
> https://repl.it/FMin/8
Don't make it unnecessarily hard to find your code -- as long as it's small 
you can include it into your mail

Given

> with open('partite.txt', 'r') as f:
>     splitted = [(int(line.split("'")[0]), line) for line in f]
>     splitted.sort()
>     lsorted = [line for (m, line) in splitted]
>     for z in lsorted:
>         print(z)
> 

with partite.txt looking like this

> 74' Kessie'
> 90' + 4' D'alessandro
> 51' Mchedlidze
> 54' Banega
> 56' Icardi
> 65' Icardi
> 14' Sau


Assuming you want to perform a numerical sort on the numbers before the ' 
you can just apply sorted

with open(...) as f:
    print("".join(sorted(f))

as long as all number strings have the same length. 

If that's not the case python's sorted() has decorate-sort-undecorate 
capabilities built in -- no need to do it manually:

with open("partite.txt") as f:
    by_number = sorted(f, key=lambda line: int(line.partition("'")[0]))
    print("".join(by_number))




From grant.b.edwards at gmail.com  Wed Jan 18 15:21:53 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Wed, 18 Jan 2017 20:21:53 +0000 (UTC)
Subject: sorting list python
References: <o5ogv8$13mj$1@gioia.aioe.org>
Message-ID: <o5oip1$dhc$1@blaine.gmane.org>

On 2017-01-18, Smith <smith at smith.it> wrote:

> could you do better?

Yes.

> link code:
> https://repl.it/FMin/8

I would have done better by posting the actual code instead of a blind
link that may point to Dog-knows-what...

-- 
Grant Edwards               grant.b.edwards        Yow! I had pancake makeup
                                  at               for brunch!
                              gmail.com            



From python at mrabarnett.plus.com  Wed Jan 18 15:34:25 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Wed, 18 Jan 2017 20:34:25 +0000
Subject: sorting list python
In-Reply-To: <o5ogv8$13mj$1@gioia.aioe.org>
References: <o5ogv8$13mj$1@gioia.aioe.org>
Message-ID: <74d49140-9405-f367-1223-90f8f24faccd@mrabarnett.plus.com>

On 2017-01-18 19:51, Smith wrote:
> Hi all,
> could you do better?
> Thank you in advance
>
> link code:
> https://repl.it/FMin/8
>
If you're wondering about the blank lines, it's because the lines end 
with '\n', which starts a new line, and the print function also starts a 
new line after printing the string.

Try stripping the '\n' off the end of the line read in with the .rstrip 
method.



From smith at smith.it  Wed Jan 18 15:35:21 2017
From: smith at smith.it (Smith)
Date: Wed, 18 Jan 2017 21:35:21 +0100
Subject: sorting list python
References: <o5ogv8$13mj$1@gioia.aioe.org> <o5oilu$n9k$1@blaine.gmane.org>
 <mailman.10.1484770857.9761.python-list@python.org>
Message-ID: <7ad5b0d4-5142-a39a-816b-16c90e53fc10@smith.it>

On 18/01/2017 21:20, Peter Otten wrote:
> with open("partite.txt") as f:
>     by_number = sorted(f, key=lambda line: int(line.partition("'")[0]))
>     print("".join(by_number))


Great!!! :-)


From smith at smith.it  Wed Jan 18 15:35:54 2017
From: smith at smith.it (Smith)
Date: Wed, 18 Jan 2017 21:35:54 +0100
Subject: sorting list python
References: <o5ogv8$13mj$1@gioia.aioe.org> <o5oip1$dhc$1@blaine.gmane.org>
 <mailman.11.1484770939.9761.python-list@python.org>
Message-ID: <3d5af145-cfa5-7399-2f13-86849cf3893a@smith.it>

On 18/01/2017 21:21, Grant Edwards wrote:
> I would have done better by posting the actual code instead of a blind
> link that may point to Dog-knows-what...

sorry :-(


From smith at smith.it  Wed Jan 18 15:38:31 2017
From: smith at smith.it (Smith)
Date: Wed, 18 Jan 2017 21:38:31 +0100
Subject: sorting list python
References: <o5ogv8$13mj$1@gioia.aioe.org>
 <74d49140-9405-f367-1223-90f8f24faccd@mrabarnett.plus.com>
 <mailman.12.1484771668.9761.python-list@python.org>
Message-ID: <e16d0cdd-fee7-a2cb-cc6c-4c745c852c8d@smith.it>

On 18/01/2017 21:34, MRAB wrote:
> If you're wondering about the blank lines, it's because the lines end
> with '\n', which starts a new line, and the print function also starts a
> new line after printing the string.
>
> Try stripping the '\n' off the end of the line read in with the .rstrip
> method.

Thank you for your kind cooperation


From german.fajardo at gmail.com  Wed Jan 18 16:23:37 2017
From: german.fajardo at gmail.com (=?UTF-8?Q?Germ=C3=A1n_Fajardo?=)
Date: Wed, 18 Jan 2017 16:23:37 -0500
Subject: sorting list python
In-Reply-To: <e16d0cdd-fee7-a2cb-cc6c-4c745c852c8d@smith.it>
References: <o5ogv8$13mj$1@gioia.aioe.org>
 <74d49140-9405-f367-1223-90f8f24faccd@mrabarnett.plus.com>
 <mailman.12.1484771668.9761.python-list@python.org>
 <e16d0cdd-fee7-a2cb-cc6c-4c745c852c8d@smith.it>
Message-ID: <CA+jgQeuPnvkEHaJnijeWG9TMq4pW4weLNqaT2i1du9CtB1G8XA@mail.gmail.com>

with open('partite.txt', 'r') as r:
    for line in sorted(r):
        print(line, end='')

2017-01-18 15:38 GMT-05:00 Smith <smith at smith.it>:

> On 18/01/2017 21:34, MRAB wrote:
>
>> If you're wondering about the blank lines, it's because the lines end
>> with '\n', which starts a new line, and the print function also starts a
>> new line after printing the string.
>>
>> Try stripping the '\n' off the end of the line read in with the .rstrip
>> method.
>>
>
> Thank you for your kind cooperation
> --
> https://mail.python.org/mailman/listinfo/python-list
>



-- 
Atentamente




Germ?n A. Fajardo G.


From martin.schoon at gmail.com  Wed Jan 18 16:41:34 2017
From: martin.schoon at gmail.com (Martin =?UTF-8?Q?Sch=C3=B6=C3=B6n?=)
Date: 18 Jan 2017 21:41:34 GMT
Subject: Adding colormaps?
Message-ID: <eea5oeF2d3aU1@mid.individual.net>

Is there a way to add colormaps to Matplotlib?

What I would like to do is to add the perceptually uniform 
sequential colormaps introduced in version 1.5.something.
I would like to do this without breaking my Debian system
in which Matplotlib version 1.4.2 is the newest version
available in the repo.

/Martin


From torriem at gmail.com  Wed Jan 18 16:49:11 2017
From: torriem at gmail.com (Michael Torrie)
Date: Wed, 18 Jan 2017 14:49:11 -0700
Subject: Python 3.6 Installation
In-Reply-To: <CACL+1asG-CEveF9rj4vV=WDjvBDC-KW_B_QQZpioXV4bgo0j8w@mail.gmail.com>
References: <061F1A8C6BEA684BBC8CC0972537D3D024DBA9BB@AUSP07DAG0106.hostedmail.local>
 <o5m5vg$jhf$1@blaine.gmane.org>
 <4ef0f5b2-01f0-72ae-b6e7-add88d5bacc0@gmail.com>
 <mailman.0.1484703048.9761.python-list@python.org>
 <587ecf06$0$1522$c3e8da3$5496439d@news.astraweb.com>
 <5dd005ca-1022-0521-d70c-b8f007477663@gmail.com>
 <o5n1l2$umt$1@blaine.gmane.org>
 <CACL+1asG-CEveF9rj4vV=WDjvBDC-KW_B_QQZpioXV4bgo0j8w@mail.gmail.com>
Message-ID: <7166beae-0e95-f98a-32d2-5cdf9e0f55cb@gmail.com>

On 01/18/2017 10:59 AM, eryk sun wrote:
> On Wed, Jan 18, 2017 at 6:23 AM, Terry Reedy <tjreedy at udel.edu> wrote:
>> Not everyone has run Windows update since the current runtime was released.
> 
> Python's installer tries (and sometimes fails) to install the
> KB2999226 update, which installs an old version of the Universal CRT.
> Some installers instead bundle the VC++ redistributable, which
> includes KB2999226, but that would be overkill for CPython. I thought
> we could phase this out in 3.6 to instead require an up-to-date OS. If
> people need offline updates, as opposed to using Windows update, it's
> better to get the most recent version directly from Microsoft,
> KB3118401 [1]. Steve Dower disagreed, and that's the end of it.
> 
> As to the loader returning STATUS_INVALID_IMAGE_FORMAT (0xC000007B), I
> would run the executable/script under a debugger such as WinDbg or
> cdb, with loader snaps enabled via gflags. Find the troublesome
> DLL(s), and manually resolve the problem.
> 
> [1]: https://support.microsoft.com/en-us/kb/3118401
> 

Thanks for the clarifications, Erik. Appreciate it.


From ethan at stoneleaf.us  Wed Jan 18 17:02:47 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Wed, 18 Jan 2017 14:02:47 -0800
Subject: Emulating Final classes in Python
In-Reply-To: <587F96BA.8070707@stoneleaf.us>
References: <587dc242$0$1601$c3e8da3$5496439d@news.astraweb.com>
 <19450be4-a788-0e38-d70d-33d3edebc19e@rece.vub.ac.be>
 <587EF234.90502@stoneleaf.us>
 <mailman.2.1484714523.9761.python-list@python.org>
 <587f13c0$0$1590$c3e8da3$5496439d@news.astraweb.com>
 <587F96BA.8070707@stoneleaf.us>
Message-ID: <587FE607.7040002@stoneleaf.us>

On 01/18/2017 08:24 AM, Ethan Furman wrote:
> On 01/17/2017 11:05 PM, Steven D'Aprano wrote:

>> I've given a metaclass that disallows subclassing:
>>
>> class MyClass(MyParent, metaclass=FinalMeta):
>>      ...
>>
>>
>> Ethan took that one step further by giving a class you inherit from to disallow
>> subclassing:
>>
>> class MyClass(MyParent, Final):
>>      ...
>>
>>
>> Could we solve this problem with a decorator?
>>
>>
>> @final
>> class MyClass(MyParent):
>>      ...
>>
>>
>> Without needing to add any special magic to MyParent or MyClass, apart from the
>> decorator, can we make MyClass final? That would (in principle) allow us to
>> make a subclass, and *then* set the class final so that no more subclasses
>> could be made.
>>
>>
>> I thought that the decorator could simply set the class' metaclass:
>>
>> def final(cls):
>>      if cls.__class__ is type:
>>          cls.__class__ = Meta
>>          return cls
>>      raise TypeErrror('Possible metaclass conflict')
>>
>>
>> but that's disallowed. Any ideas?
>
> You still need to have the FinalMeta type and Final class available, but to use a
>  decorator you'll need to scavenge the bits from the old class to make a new class
>  of the same name and return that:
>
> def final(cls):
>      new_cls = Meta(cls.__name__, (Final, )+cls.__bases__, dict(cls.__dict__))
>      return new_cls
>
> Not sure if more is needed to handle __slots__, but this should get us started.

One problem with the above is existing instances won't be modified to inherit from the updated class.  I am unsure if that is solvable before 3.6, but in 3.6 one can use the new __init_subclass__ to avoid a Final base class, a FinalMeta type, and just update the existing class:

def final(cls):
     def init_subclass(cls, **kwargs):
         raise Exception('Final class cannot be subclassed')
     cls.__init_subclass__ = classmethod(init_subclass)
     return cls

This can be used as a decorator at class creation time, or at any later date to lock down a class.  The downside is it's less obvious that the class is final... meaning there are no clues in the MRO.

--
~Ethan~


From steve+python at pearwood.info  Wed Jan 18 20:36:51 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Thu, 19 Jan 2017 12:36:51 +1100
Subject: Emulating Final classes in Python
References: <587dc242$0$1601$c3e8da3$5496439d@news.astraweb.com>
 <19450be4-a788-0e38-d70d-33d3edebc19e@rece.vub.ac.be>
 <587EF234.90502@stoneleaf.us>
 <mailman.2.1484714523.9761.python-list@python.org>
 <587f13c0$0$1590$c3e8da3$5496439d@news.astraweb.com>
 <587F96BA.8070707@stoneleaf.us> <587FE607.7040002@stoneleaf.us>
 <mailman.16.1484776970.9761.python-list@python.org>
Message-ID: <58801837$0$1606$c3e8da3$5496439d@news.astraweb.com>

On Thu, 19 Jan 2017 09:02 am, Ethan Furman wrote:

[...]
> One problem with the above is existing instances won't be modified to
> inherit from the updated class.  I am unsure if that is solvable before
> 3.6, but in 3.6 one can use the new __init_subclass__ to avoid a Final
> base class, a FinalMeta type, and just update the existing class:
> 
> def final(cls):
>      def init_subclass(cls, **kwargs):
>          raise Exception('Final class cannot be subclassed')
>      cls.__init_subclass__ = classmethod(init_subclass)
>      return cls
> 
> This can be used as a decorator at class creation time, or at any later
> date to lock down a class.  The downside is it's less obvious that the
> class is final... meaning there are no clues in the MRO.

Ah nice! I didn't know about __init__subclass__.



-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From jobmattcon at gmail.com  Thu Jan 19 03:04:30 2017
From: jobmattcon at gmail.com (Ho Yeung Lee)
Date: Thu, 19 Jan 2017 00:04:30 -0800 (PST)
Subject: Must target be only one bit one such as 0001,0010,0100,1000 In
 supervised neural learning f(w*p+b) with perceptron rule w = w + e for linear
 case?
Message-ID: <f353c219-a7a1-4592-94a4-8387ac254491@googlegroups.com>

Must target be only one bit one such as 0001,0010,0100,1000 In supervised neural learning f(w*p+b) with perceptron rule w = w + e for linear case?

with neural network design

does it means that can not use two or more one as target such as 0011,0110,1100,1010, 0111,1110,1101, etc when training weight?


From johann.spies at gmail.com  Thu Jan 19 05:16:19 2017
From: johann.spies at gmail.com (Johann Spies)
Date: Thu, 19 Jan 2017 12:16:19 +0200
Subject: Python for WEB-page !?
In-Reply-To: <0b621aaa-03d0-0e72-f12d-030189e6a3f1@harvee.org>
References: <4df49556-ce91-4ca5-8d9e-f505d7f1a1e9@googlegroups.com>
 <eba3dc40-05ec-0d17-21c9-0907da4ecaca@gmail.com>
 <0b621aaa-03d0-0e72-f12d-030189e6a3f1@harvee.org>
Message-ID: <CAGZ55DQ=kD8Q-KT=Gurnn-8uxio5vUyc6LweCEDEo3Du_+Lo-A@mail.gmail.com>

It might be worth while to look at web2py (http://web2py.com).

Here is a good tutorial: http://killer-web-development.com/

Regards
Johann

-- 
Because experiencing your loyal love is better than life itself,
my lips will praise you.  (Psalm 63:3)


From davidbenny2000 at gmail.com  Thu Jan 19 05:54:03 2017
From: davidbenny2000 at gmail.com (Ho Yeung Lee)
Date: Thu, 19 Jan 2017 02:54:03 -0800 (PST)
Subject: Is "two different input map to one unique target called nonlinear
 case " or "one unique input map to two different target called nonlinear
 case"? Which learning method can train these two cases or no method to train
 one of case?
Message-ID: <fffe8244-f1b8-495b-b764-7e2fb1573c63@googlegroups.com>

Is "two different input map to one unique target called nonlinear case " or "one unique input map to two different target called nonlinear case"? Which learning method can train these two cases or no method to train one of case?


From Cecil at decebal.nl  Thu Jan 19 10:06:40 2017
From: Cecil at decebal.nl (Cecil Westerhof)
Date: Thu, 19 Jan 2017 16:06:40 +0100
Subject: ipython2 does not work anymore
Message-ID: <87bmv3xf5r.fsf@Equus.decebal.nl>

I did not work with ipython2 for a long time. Most of my work is done
with python3. I just tried to start ipython2 and got:
Traceback (most recent call last):
  File "/usr/bin/ipython2", line 7, in <module>
    from IPython import start_ipython
  File "/usr/lib/python2.7/site-packages/IPython/__init__.py", line 49, in <module>
    from .terminal.embed import embed
  File "/usr/lib/python2.7/site-packages/IPython/terminal/embed.py", line 16, in <module>
    from IPython.core.interactiveshell import DummyMod, InteractiveShell
  File "/usr/lib/python2.7/site-packages/IPython/core/interactiveshell.py", line 31, in <module>
    from pickleshare import PickleShareDB
  File "/usr/lib/python2.7/site-packages/pickleshare.py", line 40, in <module>
    from path import path as Path
ImportError: No module named path


What could be the problem here?


Python2 does work:
Python 2.7.12 (default, Jul 01 2016, 15:36:53) [GCC] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> 

Otherwise I would have a problem. Some scripts still use it.

I am working with openSUSE 13.2

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof


From rosuav at gmail.com  Thu Jan 19 13:21:44 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 20 Jan 2017 05:21:44 +1100
Subject: Odd message while building Python from tip
Message-ID: <CAPTjJmpb4b6EVt1hnX8Mra9-RHY8_OiUrJbuHZ6O091tBr0+QA@mail.gmail.com>

I don't think I've ever seen this message before. This is just after
'hg pull -u' to get to the latest CPython (my previous build was about
a month ago). 'make' succeeded, but concluded with this message:

running build_ext
The following modules found by detect_modules() in setup.py, have been
built by the Makefile instead, as configured by the Setup files:
atexit                pwd                   time

And then proceeded to run build_scripts as normal.

It doesn't look like an error, and those three modules can happily be
imported by "./python" and by the freshly-installed "python3.7". It's
curious though. Any explanation?

ChrisA


From Cecil at decebal.nl  Thu Jan 19 14:08:32 2017
From: Cecil at decebal.nl (Cecil Westerhof)
Date: Thu, 19 Jan 2017 20:08:32 +0100
Subject: Using python to start programs after logging in
Message-ID: <878tq6amvj.fsf@Equus.decebal.nl>

I am writing a python program to start the programs that need to be
started after logging in.

I have the following imports:
    from subprocess import check_call, Popen, STDOUT
    from time       import sleep, strftime

And use the following code:
    check_call(tuple('wmctrl -s 10'.split()))
    log_file = open('Logging/firefox_%T.log'.replace('%T', strftime('%F_%R')), 'w')
    Popen(tuple('firefox'.split()), stdout = log_file, stderr = STDOUT)

The first statement is to go to the correct desktop.

Is this a good way to do things, or could I do it in a better way?

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof


From gordon at panix.com  Thu Jan 19 14:29:05 2017
From: gordon at panix.com (John Gordon)
Date: Thu, 19 Jan 2017 19:29:05 +0000 (UTC)
Subject: Using python to start programs after logging in
References: <878tq6amvj.fsf@Equus.decebal.nl>
Message-ID: <o5r421$5b$1@reader1.panix.com>

In <878tq6amvj.fsf at Equus.decebal.nl> Cecil Westerhof <Cecil at decebal.nl> writes:

> I am writing a python program to start the programs that need to be
> started after logging in.

> Is this a good way to do things, or could I do it in a better way?

I think using your window manager's built-in facilities for starting
programs would be better.  Why are you using Python instead?

-- 
John Gordon                   A is for Amy, who fell down the stairs
gordon at panix.com              B is for Basil, assaulted by bears
                                -- Edward Gorey, "The Gashlycrumb Tinies"



From python at mrabarnett.plus.com  Thu Jan 19 15:08:34 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Thu, 19 Jan 2017 20:08:34 +0000
Subject: ipython2 does not work anymore
In-Reply-To: <87bmv3xf5r.fsf@Equus.decebal.nl>
References: <87bmv3xf5r.fsf@Equus.decebal.nl>
Message-ID: <35dadf92-ada7-02ce-3449-750cb914c426@mrabarnett.plus.com>

On 2017-01-19 15:06, Cecil Westerhof wrote:
> I did not work with ipython2 for a long time. Most of my work is done
> with python3. I just tried to start ipython2 and got:
> Traceback (most recent call last):
>   File "/usr/bin/ipython2", line 7, in <module>
>     from IPython import start_ipython
>   File "/usr/lib/python2.7/site-packages/IPython/__init__.py", line 49, in <module>
>     from .terminal.embed import embed
>   File "/usr/lib/python2.7/site-packages/IPython/terminal/embed.py", line 16, in <module>
>     from IPython.core.interactiveshell import DummyMod, InteractiveShell
>   File "/usr/lib/python2.7/site-packages/IPython/core/interactiveshell.py", line 31, in <module>
>     from pickleshare import PickleShareDB
>   File "/usr/lib/python2.7/site-packages/pickleshare.py", line 40, in <module>
>     from path import path as Path
> ImportError: No module named path
>
>
> What could be the problem here?
>
>
> Python2 does work:
> Python 2.7.12 (default, Jul 01 2016, 15:36:53) [GCC] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
>>>>
>
> Otherwise I would have a problem. Some scripts still use it.
>
> I am working with openSUSE 13.2
>
There's no module called 'path' in Python 3. Do you mean 'pathlib'?

If you do mean 'pathlib', it was introduced in Python 3.4.



From python at mrabarnett.plus.com  Thu Jan 19 15:12:30 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Thu, 19 Jan 2017 20:12:30 +0000
Subject: Using python to start programs after logging in
In-Reply-To: <878tq6amvj.fsf@Equus.decebal.nl>
References: <878tq6amvj.fsf@Equus.decebal.nl>
Message-ID: <a26a0a12-c8b3-de15-4f54-dfb138cee56a@mrabarnett.plus.com>

On 2017-01-19 19:08, Cecil Westerhof wrote:
> I am writing a python program to start the programs that need to be
> started after logging in.
>
> I have the following imports:
>     from subprocess import check_call, Popen, STDOUT
>     from time       import sleep, strftime
>
> And use the following code:
>     check_call(tuple('wmctrl -s 10'.split()))
>     log_file = open('Logging/firefox_%T.log'.replace('%T', strftime('%F_%R')), 'w')
>     Popen(tuple('firefox'.split()), stdout = log_file, stderr = STDOUT)
>
> The first statement is to go to the correct desktop.
>
> Is this a good way to do things, or could I do it in a better way?
>
Apart from the other answer, your use of .replace is odd. This would be 
better:

     log_file = open('Logging/firefox_%s.log' % strftime('%F_%R'), 'w')

Even better would be to use the 'with' statement as well.



From Cecil at decebal.nl  Thu Jan 19 16:11:31 2017
From: Cecil at decebal.nl (Cecil Westerhof)
Date: Thu, 19 Jan 2017 22:11:31 +0100
Subject: Using python to start programs after logging in
References: <878tq6amvj.fsf@Equus.decebal.nl> <o5r421$5b$1@reader1.panix.com>
Message-ID: <878tq6hi0s.fsf@Equus.decebal.nl>

On Thursday 19 Jan 2017 20:29 CET, John Gordon wrote:

> In <878tq6amvj.fsf at Equus.decebal.nl> Cecil Westerhof
> <Cecil at decebal.nl> writes:
>
>> I am writing a python program to start the programs that need to be
>> started after logging in.
>
>> Is this a good way to do things, or could I do it in a better way?
>
> I think using your window manager's built-in facilities for starting
> programs would be better.  Why are you using Python instead?

Because when you use the window managers builtin facilities then all
programs will be started on the same virtual desktop and I want to
start them on different ones.

Second reason is that I want to fetch the programs to start from a
database so I can easily change the programs to be started.

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof


From Cecil at decebal.nl  Thu Jan 19 16:12:43 2017
From: Cecil at decebal.nl (Cecil Westerhof)
Date: Thu, 19 Jan 2017 22:12:43 +0100
Subject: ipython2 does not work anymore
References: <87bmv3xf5r.fsf@Equus.decebal.nl>
 <35dadf92-ada7-02ce-3449-750cb914c426@mrabarnett.plus.com>
 <mailman.20.1484856523.9761.python-list@python.org>
Message-ID: <874m0uhhys.fsf@Equus.decebal.nl>

On Thursday 19 Jan 2017 21:08 CET, MRAB wrote:

> On 2017-01-19 15:06, Cecil Westerhof wrote:
>> I did not work with ipython2 for a long time. Most of my work is
>> done with python3. I just tried to start ipython2 and got:
>> Traceback (most recent call last): File "/usr/bin/ipython2", line
>> 7, in <module> from IPython import start_ipython File
>> "/usr/lib/python2.7/site-packages/IPython/__init__.py", line 49, in
>> <module> from .terminal.embed import embed File
>> "/usr/lib/python2.7/site-packages/IPython/terminal/embed.py", line
>> 16, in <module> from IPython.core.interactiveshell import DummyMod,
>> InteractiveShell File
>> "/usr/lib/python2.7/site-packages/IPython/core/interactiveshell.py",
>> line 31, in <module> from pickleshare import PickleShareDB File
>> "/usr/lib/python2.7/site-packages/pickleshare.py", line 40, in
>> <module> from path import path as Path ImportError: No module named
>> path
>>
>>
>> What could be the problem here?
>>
>>
>> Python2 does work: Python 2.7.12 (default, Jul 01 2016, 15:36:53)
>> [GCC] on linux2 Type "help", "copyright", "credits" or "license"
>> for more information.
>>>>>
>>
>> Otherwise I would have a problem. Some scripts still use it.
>>
>> I am working with openSUSE 13.2
>>
> There's no module called 'path' in Python 3. Do you mean 'pathlib'?

I copied this from the output I got.


> If you do mean 'pathlib', it was introduced in Python 3.4.

It is about python2.

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof


From Cecil at decebal.nl  Thu Jan 19 16:21:59 2017
From: Cecil at decebal.nl (Cecil Westerhof)
Date: Thu, 19 Jan 2017 22:21:59 +0100
Subject: Using python to start programs after logging in
References: <878tq6amvj.fsf@Equus.decebal.nl>
 <a26a0a12-c8b3-de15-4f54-dfb138cee56a@mrabarnett.plus.com>
 <mailman.21.1484856755.9761.python-list@python.org>
Message-ID: <87ziimg2yw.fsf@Equus.decebal.nl>

On Thursday 19 Jan 2017 21:12 CET, MRAB wrote:

> On 2017-01-19 19:08, Cecil Westerhof wrote:
>> I am writing a python program to start the programs that need to be
>> started after logging in.
>>
>> I have the following imports:
>> from subprocess import check_call, Popen, STDOUT
>> from time       import sleep, strftime
>>
>> And use the following code: check_call(tuple('wmctrl -s
>> 10'.split())) log_file =
>> open('Logging/firefox_%T.log'.replace('%T', strftime('%F_%R')),
>> 'w') Popen(tuple('firefox'.split()), stdout = log_file, stderr =
>> STDOUT)
>>
>> The first statement is to go to the correct desktop.
>>
>> Is this a good way to do things, or could I do it in a better way?
>>
> Apart from the other answer, your use of .replace is odd. This would
> be better:
>
> log_file = open('Logging/firefox_%s.log' % strftime('%F_%R'), 'w')

The reason is that it is ?generic? code. In the future instead of
string it will be a variable and only when the variable contains %T it
should be replaced.


> Even better would be to use the 'with' statement as well.

The same here. Not always has the output to be logged and then I would
use NONE for log_file.

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof


From songofacandy at gmail.com  Thu Jan 19 18:09:37 2017
From: songofacandy at gmail.com (INADA Naoki)
Date: Fri, 20 Jan 2017 08:09:37 +0900
Subject: Odd message while building Python from tip
In-Reply-To: <CAPTjJmpb4b6EVt1hnX8Mra9-RHY8_OiUrJbuHZ6O091tBr0+QA@mail.gmail.com>
References: <CAPTjJmpb4b6EVt1hnX8Mra9-RHY8_OiUrJbuHZ6O091tBr0+QA@mail.gmail.com>
Message-ID: <CAEfz+Tyo9yxNEX1nYMdOFXGVg1AdCAcex5UhTKzuRop00brfog@mail.gmail.com>

Hi, Chris.

They are "builtin" module.
python executable contains the modules already.

But I don't know it's safe to remove them from setup.py.
There are so many platforms and special build of Python.


$ ./python
Python 3.7.0a0 (default:9f7d16266928, Jan 18 2017, 23:59:22)
[GCC 6.2.0 20161005] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.builtin_module_names
('_ast', '_codecs', '_collections', '_functools', '_imp', '_io',
'_locale', '_operator', '_signal', '_sre', '_stat', '_string',
'_symtable', '_thread', '_tracemalloc', '_warnings', '_weakref',
'atexit', 'builtins', 'errno', 'faulthandler', 'gc', 'itertools',
'marshal', 'posix', 'pwd', 'sys', 'time', 'xxsubtype', 'zipimport')



On Fri, Jan 20, 2017 at 3:21 AM, Chris Angelico <rosuav at gmail.com> wrote:
> I don't think I've ever seen this message before. This is just after
> 'hg pull -u' to get to the latest CPython (my previous build was about
> a month ago). 'make' succeeded, but concluded with this message:
>
> running build_ext
> The following modules found by detect_modules() in setup.py, have been
> built by the Makefile instead, as configured by the Setup files:
> atexit                pwd                   time
>
> And then proceeded to run build_scripts as normal.
>
> It doesn't look like an error, and those three modules can happily be
> imported by "./python" and by the freshly-installed "python3.7". It's
> curious though. Any explanation?
>
> ChrisA
> --
> https://mail.python.org/mailman/listinfo/python-list


From Cecil at decebal.nl  Thu Jan 19 18:36:41 2017
From: Cecil at decebal.nl (Cecil Westerhof)
Date: Fri, 20 Jan 2017 00:36:41 +0100
Subject: Using python to start programs after logging in
References: <878tq6amvj.fsf@Equus.decebal.nl>
 <a26a0a12-c8b3-de15-4f54-dfb138cee56a@mrabarnett.plus.com>
 <mailman.21.1484856755.9761.python-list@python.org>
 <87ziimg2yw.fsf@Equus.decebal.nl>
Message-ID: <87shoefwqe.fsf@Equus.decebal.nl>

On Thursday 19 Jan 2017 22:21 CET, Cecil Westerhof wrote:

> On Thursday 19 Jan 2017 21:12 CET, MRAB wrote:
>
>> On 2017-01-19 19:08, Cecil Westerhof wrote:
>>> I am writing a python program to start the programs that need to
>>> be started after logging in.
>>>
>>> I have the following imports:
>>> from subprocess import check_call, Popen, STDOUT
>>> from time       import sleep, strftime
>>>
>>> And use the following code: check_call(tuple('wmctrl -s
>>> 10'.split())) log_file =
>>> open('Logging/firefox_%T.log'.replace('%T', strftime('%F_%R')),
>>> 'w') Popen(tuple('firefox'.split()), stdout = log_file, stderr =
>>> STDOUT)
>>>
>>> The first statement is to go to the correct desktop.
>>>
>>> Is this a good way to do things, or could I do it in a better way?
>>>
>> Apart from the other answer, your use of .replace is odd. This
>> would be better:
>>
>> log_file = open('Logging/firefox_%s.log' % strftime('%F_%R'), 'w')
>
> The reason is that it is ?generic? code. In the future instead of
> string it will be a variable and only when the variable contains %T
> it should be replaced.
>
>
>> Even better would be to use the 'with' statement as well.
>
> The same here. Not always has the output to be logged and then I
> would use NONE for log_file.

I wrote a function for switching to the correct virtual desktop and
starting all the commands. I am also using with now:
def do_desktop(desktop, commands, seconds_to_wait = 10):
    desktop_command = ('wmctrl -s ' + desktop).split()
    check_call(tuple(desktop_command))
    for command_arr in commands:
        command         = command_arr[0].split()
        log_directory   = command_arr[1]
        directory       = command_arr[2]
        if (directory != ''):
            chdir(directory)
        if (log_directory == 'NONE'):
            Popen(tuple(command.split()))
        else:
            log_file_name = log_directory.replace('%T', strftime('%F_%R'))
            with open(log_file_name, 'w') as log_file:
                Popen(tuple(command), stdout = log_file, stderr = STDOUT)
        if (directory != ''):
            set_default_dir()
    sleep(seconds_to_wait)


The function set_default_dir:
def set_default_dir():
    chdir(expanduser('~'))


The example with firefox is then done with:
commands = [
    ['firefox', 'Logging/firefox_%T.log', ''],
]
do_desktop('10', commands, 30)


Sometimes a command needs to be executed in a different directory,
that is done like:
commands = [
    ['lein run',                                                                    'NONE', 'Clojure/Quotes'],
    ['xfce4-terminal --maximize --execute screen -S Clojure -c ~/.screenrcClojure', 'NONE', ''],
]
do_desktop('6', commands, 30)

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof


From rosuav at gmail.com  Thu Jan 19 18:49:15 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 20 Jan 2017 10:49:15 +1100
Subject: Odd message while building Python from tip
In-Reply-To: <CAEfz+Tyo9yxNEX1nYMdOFXGVg1AdCAcex5UhTKzuRop00brfog@mail.gmail.com>
References: <CAPTjJmpb4b6EVt1hnX8Mra9-RHY8_OiUrJbuHZ6O091tBr0+QA@mail.gmail.com>
 <CAEfz+Tyo9yxNEX1nYMdOFXGVg1AdCAcex5UhTKzuRop00brfog@mail.gmail.com>
Message-ID: <CAPTjJmqTFppHq-iq-TLdcQ+zgqQFa7s1uw2tXvJNJOOD4DYvVw@mail.gmail.com>

On Fri, Jan 20, 2017 at 10:09 AM, INADA Naoki <songofacandy at gmail.com> wrote:
> Hi, Chris.
>
> They are "builtin" module.
> python executable contains the modules already.
>
> But I don't know it's safe to remove them from setup.py.
> There are so many platforms and special build of Python.

I haven't changed the code in any way, btw. This is a vanilla CPython
(at the moment - there have been times I've had patches sitting
around), and this message is, I believe, new.

ChrisA


From steve+python at pearwood.info  Thu Jan 19 19:01:09 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Fri, 20 Jan 2017 11:01:09 +1100
Subject: ipython2 does not work anymore
References: <87bmv3xf5r.fsf@Equus.decebal.nl>
Message-ID: <58815347$0$1620$c3e8da3$5496439d@news.astraweb.com>

On Fri, 20 Jan 2017 02:06 am, Cecil Westerhof wrote:

> I did not work with ipython2 for a long time. Most of my work is done
> with python3. I just tried to start ipython2 and got:
> Traceback (most recent call last):
[...]
> ImportError: No module named path
> 
> 
> What could be the problem here?

Something has changed between the last time you ran IPython and now. You
have deleted something, changed something, installed something... or you
have file system corruption and files are disappearing... or your 
PYTHONPATH environment variable is not set, or is set differently to the way
it used to be...

Do you want to investigate why the error occurred, or just fix it in the
most convenient and easy way?

If the second, then you can probably fix it by running:

python2 -m pip install path

assuming that you trust that path is a legitimate module.

Looking at the traceback, I see the final call which fails is in a module
called pickleshare.py:

  File "/usr/lib/python2.7/site-packages/pickleshare.py", line 40, in <module>
    from path import path as Path


You could try removing pickleshare and re-installing, or upgrading to the
latest version, and see whether it brings in the "path" dependency.

You could try running "locate path.py | grep python2.7" in the shell and see
whether path is installed. If it is installed, it sounds like the PYTHONPATH
is messed up. Run these and tell us what they say:

locate path.py | grep python2.7
python2.7 -c "import sys; print sys.path"
echo $PYTHONPATH



Googling for your error gives me these two relevant looking hits:

https://duckduckgo.com/html/?q=%22ImportError:%20No%20module%20named%20path%22+ipython

https://github.com/jupyter/notebook/issues/270

https://github.com/jupyter/notebook/issues/525



-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, 
and sure enough, things got worse.



From saxri89 at gmail.com  Thu Jan 19 19:03:33 2017
From: saxri89 at gmail.com (Xristos Xristoou)
Date: Thu, 19 Jan 2017 16:03:33 -0800 (PST)
Subject: python corrupted double-linked list error
Message-ID: <d084e8cc-06df-46dd-8b5e-5d516bb115ab@googlegroups.com>

i am a python 2.7 and ubuntu 16.04 user and i have unexpected error when try to excute some python scripts . i use pycharm and i have the some error when i try to run python script from the ubuntu terminal. the error :

*** Error in `/usr/bin/python2.7': corrupted double-linked list: 0x0b83c880 ***

the error message :

======= Backtrace: =========
/lib/i386-linux-gnu/libc.so.6(+0x67377)[0xb764b377]
/lib/i386-linux-gnu/libc.so.6(+0x6d2f7)[0xb76512f7]
/lib/i386-linux-gnu/libc.so.6(+0x6e2f1)[0xb76522f1]
/usr/lib/i386-linux-gnu/libstdc++.so.6(_ZdlPv+0x18)[0xb6ba9d88]
/usr/lib/libgdal.so.1(_ZN15GDALMajorObjectD0Ev+0x22)[0xb075a582]
/usr/lib/libgdal.so.1(GDALClose+0x77)[0xb074d747]
/usr/lib/qgis/plugins/libgdalprovider.so(+0xa930)[0xa4888930]
/usr/lib/qgis/plugins/libgdalprovider.so(+0xaafa)[0xa4888afa]
/usr/lib/libqgis_core.so.2.18.3(_ZN13QgsRasterPipeD1Ev+0x75)[0xb3d6a7d5]
/usr/lib/libqgis_core.so.2.18.3(_ZN14QgsRasterLayerD1Ev+0x2f)[0xb3d5cd0f]
/usr/lib/python2.7/dist-packages/qgis/_core.i386-linux-gnu.so(_ZN17sipQgsRasterLayerD1Ev+0x3b)[0xb489dd2b]
/usr/lib/python2.7/dist-packages/qgis/_core.i386-linux-gnu.so(_ZN17sipQgsRasterLayerD0Ev+0x1a)[0xb489dd5a]
/usr/lib/python2.7/dist-packages/qgis/_core.i386-linux-gnu.so(+0x43df45)[0xb4883f45]
/usr/lib/python2.7/dist-packages/qgis/_core.i386-linux-gnu.so(+0x43df8a)[0xb4883f8a]
/usr/lib/python2.7/dist-packages/sip.i386-linux-gnu.so(+0x5d49)[0xb724dd49]
/usr/lib/python2.7/dist-packages/sip.i386-linux-gnu.so(+0xc19b)[0xb725419b]
/usr/bin/python2.7[0x8144aad]
/usr/bin/python2.7[0x80fd127]
/usr/bin/python2.7(PyDict_SetItem+0x478)[0x80e9268]
/usr/bin/python2.7(_PyModule_Clear+0xba)[0x8149a1a]
/usr/bin/python2.7(PyImport_Cleanup+0x37a)[0x81495ca]
/usr/bin/python2.7(Py_Finalize+0x99)[0x8147399]
/usr/bin/python2.7(Py_Main+0x4bd)[0x80e639d]
/usr/bin/python2.7(main+0x26)[0x80e5ec6]
/lib/i386-linux-gnu/libc.so.6(__libc_start_main+0xf7)[0xb75fc637]
/usr/bin/python2.7[0x80e5dc8]
======= Memory map: ========
08048000-0838f000 r-xp 00000000 08:01 1583892    /usr/bin/python2.7
08390000-08391000 r--p 00347000 08:01 1583892    /usr/bin/python2.7
08391000-083f1000 rw-p 00348000 08:01 1583892    /usr/bin/python2.7
083f1000-08406000 rw-p 00000000 00:00 0 
0a0f7000-0ba69000 rw-p 00000000 00:00 0          [heap]
a03e0000-a03eb000 r-xp 00000000 08:01 1049930    /lib/i386-linux-gnu/libnss_files-2.23.so
a03eb000-a03ec000 r--p 0000a000 08:01 1049930    /lib/i386-linux-gnu/libnss_files-2.23.so
a03ec000-a03ed000 rw-p 0000b000 08:01 1049930    /lib/i386-linux-gnu/libnss_files-2.23.so
a03ed000-a03f3000 rw-p 00000000 00:00 0 
a03f3000-a03fe000 r-xp 00000000 08:01 1048664    /lib/i386-linux-gnu/libnss_nis-2.23.so
a03fe000-a03ff000 r--p 0000a000 08:01 1048664    /lib/i386-linux-gnu/libnss_nis-2.23.so
a03ff000-a0400000 rw-p 0000b000 08:01 1048664    /lib/i386-linux-gnu/libnss_nis-2.23.so
a0400000-a0421000 rw-p 00000000 00:00 0 
a0421000-a0500000 ---p 00000000 00:00 0 
a0509000-a0520000 r-xp 00000000 08:01 1048674    /lib/i386-linux-gnu/libnsl-2.23.so
a0520000-a0521000 r--p 00016000 08:01 1048674    /lib/i386-linux-gnu/libnsl-2.23.so
a0521000-a0522000 rw-p 00017000 08:01 1048674    /lib/i386-linux-gnu/libnsl-2.23.so
a0522000-a0524000 rw-p 00000000 00:00 0 
a0524000-a052c000 r-xp 00000000 08:01 1048675    /lib/i386-linux-gnu/libnss_compat-2.23.so
a052c000-a052d000 r--p 00007000 08:01 1048675    /lib/i386-linux-gnu/libnss_compat-2.23.so
a052d000-a052e000 rw-p 00008000 08:01 1048675    /lib/i386-linux-gnu/libnss_compat-2.23.so
a054a000-a054b000 ---p 00000000 00:00 0 
a054b000-a10cb000 rw-p 00000000 00:00 0 
a10cb000-a10d4000 r-xp 00000000 08:01 150141     /usr/lib/i386-linux-gnu/qt4/plugins/iconengines/libqsvgicon.so
a10d4000-a10d5000 r--p 00008000 08:01 150141     /usr/lib/i386-linux-gnu/qt4/plugins/iconengines/libqsvgicon.so
a10d5000-a10d6000 rw-p 00009000 08:01 150141     /usr/lib/i386-linux-gnu/qt4/plugins/iconengines/libqsvgicon.so
a10d6000-a1296000 rw-p 00000000 00:00 0 
a1296000-a12a5000 r-xp 00000000 08:01 283552     /usr/lib/python2.7/dist-packages/scipy/stats/mvn.i386-linux-gnu.so
a12a5000-a12a6000 ---p 0000f000 08:01 283552     /usr/lib/python2.7/dist-packages/scipy/stats/mvn.i386-linux-gnu.so
a12a6000-a12a7000 r--p 0000f000 08:01 283552     /usr/lib/python2.7/dist-packages/scipy/stats/mvn.i386-linux-gnu.so
a12a7000-a12a8000 rw-p 00010000 08:01 283552     /usr/lib/python2.7/dist-packages/scipy/stats/mvn.i386-linux-gnu.so
a12a8000-a139f000 rw-p 00000000 00:00 0 
a139f000-a13a8000 r-xp 00000000 08:01 283553     /usr/lib/python2.7/dist-packages/scipy/stats/statlib.i386-linux-gnu.so
a13a8000-a13a9000 ---p 00009000 08:01 283553     /usr/lib/python2.7/dist-packages/scipy/stats/statlib.i386-linux-gnu.so
a13a9000-a13aa000 r--p 00009000 08:01 283553     /usr/lib/python2.7/dist-packages/scipy/stats/statlib.i386-linux-gnu.so
a13aa000-a13ab000 rw-p 0000a000 08:01 283553     /usr/lib/python2.7/dist-packages/scipy/stats/statlib.i386-linux-gnu.so
a13ab000-a13eb000 rw-p 00000000 00:00 0 
a13eb000-a13f8000 r-xp 00000000 08:01 283548     /usr/lib/python2.7/dist-packages/scipy/stats/_rank.i386-linux-gnu.so
a13f8000-a13f9000 r--p 0000c000 08:01 283548     /usr/lib/python2.7/dist-packages/scipy/stats/_rank.i386-linux-gnu.so
a13f9000-a13fb000 rw-p 0000d000 08:01 283548     /usr/lib/python2.7/dist-packages/scipy/stats/_rank.i386-linux-gnu.so
a13fb000-a147b000 rw-p 00000000 00:00 0 
a147b000-a148e000 r-xp 00000000 08:01 283509     /usr/lib/python2.7/dist-packages/scipy/stats/vonmises_cython.i386-linux-gnu.so
a148e000-a148f000 r--p 00012000 08:01 283509     /usr/lib/python2.7/dist-packages/scipy/stats/vonmises_cython.i386-linux-gnu.so
a148f000-a1490000 rw-p 00013000 08:01 283509     /usr/lib/python2.7/dist-packages/scipy/stats/vonmises_cython.i386-linux-gnu.so
a1490000-a1510000 rw-p 00000000 00:00 0 
a1510000-a1519000 r-xp 00000000 08:01 534502     /usr/lib/python2.7/dist-packages/scipy/optimize/_nnls.i386-linux-gnu.so
a1519000-a151a000 r--p 00008000 08:01 534502     /usr/lib/python2.7/dist-packages/scipy/optimize/_nnls.i386-linux-gnu.so
a151a000-a151b000 rw-p 00009000 08:01 534502     /usr/lib/python2.7/dist-packages/scipy/optimize/_nnls.i386-linux-gnu.so
a151b000-a1539000 r-xp 00000000 08:01 534537     /usr/lib/python2.7/dist-packages/scipy/optimize/_lsq/givens_elimination.i386-linux-gnu.so
a1539000-a153a000 r--p 0001d000 08:01 534537     /usr/lib/python2.7/dist-packages/scipy/optimize/_lsq/givens_elimination.i386-linux-gnu.so
a153a000-a153c000 rw-p 0001e000 08:01 534537     /usr/lib/python2.7/dist-packages/scipy/optimize/_lsq/givens_elimination.i386-linux-gnu.so
a153c000-a1562000 r-xp 00000000 08:01 534554     /usr/lib/python2.7/dist-packages/scipy/optimize/_group_columns.i386-linux-gnu.so
a1562000-a1563000 r--p 00025000 08:01 534554     /usr/lib/python2.7/dist-packages/scipy/optimize/_group_columns.i386-linux-gnu.so
a1563000-a1565000 rw-p 00026000 08:01 534554     /usr/lib/python2.7/dist-packages/scipy/optimize/_group_columns.i386-linux-gnu.so
a1565000-a157b000 r-xp 00000000 08:01 534540     /usr/lib/python2.7/dist-packages/scipy/optimize/_minpack.i386-linux-gnu.so
a157b000-a157c000 r--p 00015000 08:01 534540     /usr/lib/python2.7/dist-packages/scipy/optimize/_minpack.i386-linux-gnu.so
a157c000-a157d000 rw-p 00016000 08:01 534540     /usr/lib/python2.7/dist-packages/scipy/optimize/_minpack.i386-linux-gnu.so
a157d000-a1592000 r-xp 00000000 08:01 534543     /usr/lib/python2.7/dist-packages/scipy/optimize/_slsqp.i386-linux-gnu.so
a1592000-a1593000 r--p 00014000 08:01 534543     /usr/lib/python2.7/dist-packages/scipy/optimize/_slsqp.i386-linux-gnu.so
a1593000-a1594000 rw-p 00015000 08:01 534543     /usr/lib/python2.7/dist-packages/scipy/optimize/_slsqp.i386-linux-gnu.so
a1594000-a15ad000 r-xp 00000000 08:01 534495     /usr/lib/python2.7/dist-packages/scipy/optimize/_cobyla.i386-linux-gnu.so
a15ad000-a15ae000 r--p 00018000 08:01 534495     /usr/lib/python2.7/dist-packages/scipy/optimize/_cobyla.i386-linux-gnu.so
a15ae000-a15af000 rw-p 00019000 08:01 534495     /usr/lib/python2.7/dist-packages/scipy/optimize/_cobyla.i386-linux-gnu.so
a15af000-a15b7000 r-xp 00000000 08:01 534499     /usr/lib/python2.7/dist-packages/scipy/optimize/moduleTNC.i386-linux-gnu.so
a15b7000-a15b8000 r--p 00007000 08:01 534499     /usr/lib/python2.7/dist-packages/scipy/optimize/moduleTNC.i386-linux-gnu.so
a15b8000-a15b9000 rw-p 00008000 08:01 534499     /usr/lib/python2.7/dist-packages/scipy/optimize/moduleTNC.i386-linux-gnu.so
a15b9000-a15f9000 rw-p 00000000 00:00 0 
a15f9000-a1689000 r-xp 00000000 08:01 412052     /usr/lib/python2.7/dist-packages/scipy/sparse/linalg/eigen/arpack/_arpack.i386-linux-gnu.so
a1689000-a168a000 r--p 0008f000 08:01 412052     /usr/lib/python2.7/dist-packages/scipy/sparse/linalg/eigen/arpack/_arpack.i386-linux-gnu.so
a168a000-a1692000 rw-p 00090000 08:01 412052     /usr/lib/python2.7/dist-packages/scipy/sparse/linalg/eigen/arpack/_arpack.i386-linux-gnu.so
a1692000-a16e9000 r-xp 00000000 08:01 412020     /usr/lib/python2.7/dist-packages/scipy/sparse/linalg/dsolve/_superlu.i386-linux-gnu.so
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a16eb000-a171f000 r-xp 00000000 08:01 412028     /usr/lib/python2.7/dist-packages/scipy/sparse/linalg/isolve/_iterative.i386-linux-gnu.so
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a1c5d000-a1c5e000 r--p 00024000 08:01 534392     /usr/lib/python2.7/dist-packages/scipy/integrate/lsoda.i386-linux-gnu.so
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a1c5f000-a1c60000 rw-p 00000000 00:00 0 
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a1c75000-a1c76000 r--p 00014000 08:01 534374     /usr/lib/python2.7/dist-packages/scipy/integrate/_dop.i386-linux-gnu.so
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a1ca3000-a1ca4000 r--p 0002a000 08:01 534376     /usr/lib/python2.7/dist-packages/scipy/integrate/vode.i386-linux-gnu.so
a1ca4000-a1ca5000 rw-p 0002b000 08:01 534376     /usr/lib/python2.7/dist-packages/scipy/integrate/vode.i386-linux-gnu.so
a1ca5000-a1ce6000 rw-p 00000000 00:00 0 
a1ce6000-a1d00000 r-xp 00000000 08:01 534375     /usr/lib/python2.7/dist-packages/scipy/integrate/_quadpack.i386-linux-gnu.so
a1d00000-a1d01000 r--p 00019000 08:01 534375     /usr/lib/python2.7/dist-packages/scipy/integrate/_quadpack.i386-linux-gnu.so
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a1d02000-a1d23000 r-xp 00000000 08:01 534393     /usr/lib/python2.7/dist-packages/scipy/integrate/_odepack.i386-linux-gnu.so
a1d23000-a1d24000 r--p 00020000 08:01 534393     /usr/lib/python2.7/dist-packages/scipy/integrate/_odepack.i386-linux-gnu.so
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a1d36000-a1d37000 r--p 00010000 08:01 701893     /usr/lib/python2.7/dist-packages/scipy/special/_ellip_harm_2.i386-linux-gnu.so
a1d37000-a1d38000 rw-p 00011000 08:01 701893     /usr/lib/python2.7/dist-packages/scipy/special/_ellip_harm_2.i386-linux-gnu.so
a1d38000-a1dd4000 r-xp 00000000 08:01 701842     /usr/lib/python2.7/dist-packages/scipy/linalg/cython_lapack.i386-linux-gnu.so
a1dd4000-a1dd5000 r--p 0009b000 08:01 701842     /usr/lib/python2.7/dist-packages/scipy/linalg/cython_lapack.i386-linux-gnu.so
a1dd5000-a1dda000 rw-p 0009c000 08:01 701842     /usr/lib/python2.7/dist-packages/scipy/linalg/cython_lapack.i386-linux-gnu.so
a1dda000-a1e0f000 r-xp 00000000 08:01 701852     /usr/lib/python2.7/dist-packages/scipy/linalg/cython_blas.i386-linux-gnu.so
a1e0f000-a1e10000 r--p 00034000 08:01 701852     /usr/lib/python2.7/dist-packages/scipy/linalg/cython_blas.i386-linux-gnu.so
a1e10000-a1e13000 rw-p 00035000 08:01 701852     /usr/lib/python2.7/dist-packages/scipy/linalg/cython_blas.i386-linux-gnu.so
a1e13000-a1e5d000 r-xp 00000000 08:01 701797     /usr/lib/python2.7/dist-packages/scipy/linalg/_decomp_update.i386-linux-gnu.so
a1e5d000-a1e5e000 r--p 00049000 08:01 701797     /usr/lib/python2.7/dist-packages/scipy/linalg/_decomp_update.i386-linux-gnu.so
a1e5e000-a1e67000 rw-p 0004a000 08:01 701797     /usr/lib/python2.7/dist-packages/scipy/linalg/_decomp_update.i386-linux-gnu.so
a1e67000-a1e97000 r-xp 00000000 08:01 701803     /usr/lib/python2.7/dist-packages/scipy/linalg/_solve_toeplitz.i386-linux-gnu.so
a1e97000-a1e98000 r--p 0002f000 08:01 701803     /usr/lib/python2.7/dist-packages/scipy/linalg/_solve_toeplitz.i386-linux-gnu.so
a1e98000-a1e9b000 rw-p 00030000 08:01 701803     /usr/lib/python2.7/dist-packages/scipy/linalg/_solve_toeplitz.i386-linux-gnu.so
a1e9b000-a1edb000 rw-p 00000000 00:00 0 
a26a1000-a26a2000 ---p 00011000 08:01 147230     /usr/lib/python2.7/dist-
bf8e6000-bf907000 rw-p 00000000 00:00 0          [stack]


From python at mrabarnett.plus.com  Thu Jan 19 19:24:49 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Fri, 20 Jan 2017 00:24:49 +0000
Subject: Using python to start programs after logging in
In-Reply-To: <87shoefwqe.fsf@Equus.decebal.nl>
References: <878tq6amvj.fsf@Equus.decebal.nl>
 <a26a0a12-c8b3-de15-4f54-dfb138cee56a@mrabarnett.plus.com>
 <mailman.21.1484856755.9761.python-list@python.org>
 <87ziimg2yw.fsf@Equus.decebal.nl> <87shoefwqe.fsf@Equus.decebal.nl>
Message-ID: <bb527e0a-4d77-8f20-e6c1-a07da10b3f1d@mrabarnett.plus.com>

On 2017-01-19 23:36, Cecil Westerhof wrote:
> On Thursday 19 Jan 2017 22:21 CET, Cecil Westerhof wrote:
>
>> On Thursday 19 Jan 2017 21:12 CET, MRAB wrote:
>>
>>> On 2017-01-19 19:08, Cecil Westerhof wrote:
>>>> I am writing a python program to start the programs that need to
>>>> be started after logging in.
>>>>
>>>> I have the following imports:
>>>> from subprocess import check_call, Popen, STDOUT
>>>> from time       import sleep, strftime
>>>>
>>>> And use the following code: check_call(tuple('wmctrl -s
>>>> 10'.split())) log_file =
>>>> open('Logging/firefox_%T.log'.replace('%T', strftime('%F_%R')),
>>>> 'w') Popen(tuple('firefox'.split()), stdout = log_file, stderr =
>>>> STDOUT)
>>>>
>>>> The first statement is to go to the correct desktop.
>>>>
>>>> Is this a good way to do things, or could I do it in a better way?
>>>>
>>> Apart from the other answer, your use of .replace is odd. This
>>> would be better:
>>>
>>> log_file = open('Logging/firefox_%s.log' % strftime('%F_%R'), 'w')
>>
>> The reason is that it is ?generic? code. In the future instead of
>> string it will be a variable and only when the variable contains %T
>> it should be replaced.
>>
>>
>>> Even better would be to use the 'with' statement as well.
>>
>> The same here. Not always has the output to be logged and then I
>> would use NONE for log_file.
>
> I wrote a function for switching to the correct virtual desktop and
> starting all the commands. I am also using with now:
> def do_desktop(desktop, commands, seconds_to_wait = 10):
>     desktop_command = ('wmctrl -s ' + desktop).split()
>     check_call(tuple(desktop_command))

You don't have to pass a tuple to check_call; it'll also accept a list.

>     for command_arr in commands:
>         command         = command_arr[0].split()
>         log_directory   = command_arr[1]
>         directory       = command_arr[2]
>         if (directory != ''):
>             chdir(directory)

There's no need for the parentheses around the 'if' condition.

>         if (log_directory == 'NONE'):
>             Popen(tuple(command.split()))
>         else:
>             log_file_name = log_directory.replace('%T', strftime('%F_%R'))
>             with open(log_file_name, 'w') as log_file:
>                 Popen(tuple(command), stdout = log_file, stderr = STDOUT)
>         if (directory != ''):
>             set_default_dir()

Using 'chdir' is generally a bad idea.

'Popen' will start the process and then continue, so what you're doing 
is changing the directory, starting a process, and then changing the 
directory again, possibly before the process has truly started (i.e. 
you've told the OS to start it, but there might be a small delay before 
that happens). Popen accepts a 'cwd' argument, which sets the 'current 
working directory' for that process.

>     sleep(seconds_to_wait)
>
>
> The function set_default_dir:
> def set_default_dir():
>     chdir(expanduser('~'))
>
>
> The example with firefox is then done with:
> commands = [
>     ['firefox', 'Logging/firefox_%T.log', ''],
> ]
> do_desktop('10', commands, 30)
>
>
> Sometimes a command needs to be executed in a different directory,
> that is done like:
> commands = [
>     ['lein run',                                                                    'NONE', 'Clojure/Quotes'],
>     ['xfce4-terminal --maximize --execute screen -S Clojure -c ~/.screenrcClojure', 'NONE', ''],
> ]
> do_desktop('6', commands, 30)
>
Why 'NONE'? Why not None?



From python at mrabarnett.plus.com  Thu Jan 19 19:35:28 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Fri, 20 Jan 2017 00:35:28 +0000
Subject: python corrupted double-linked list error
In-Reply-To: <d084e8cc-06df-46dd-8b5e-5d516bb115ab@googlegroups.com>
References: <d084e8cc-06df-46dd-8b5e-5d516bb115ab@googlegroups.com>
Message-ID: <755b72f0-e388-7fa3-a29c-1660b3594298@mrabarnett.plus.com>

On 2017-01-20 00:03, Xristos Xristoou wrote:
> i am a python 2.7 and ubuntu 16.04 user and i have unexpected error when try to excute some python scripts . i use pycharm and i have the some error when i try to run python script from the ubuntu terminal. the error :
>
> *** Error in `/usr/bin/python2.7': corrupted double-linked list: 0x0b83c880 ***
>
> the error message :
>
> ======= Backtrace: =========
> /lib/i386-linux-gnu/libc.so.6(+0x67377)[0xb764b377]
> /lib/i386-linux-gnu/libc.so.6(+0x6d2f7)[0xb76512f7]
> /lib/i386-linux-gnu/libc.so.6(+0x6e2f1)[0xb76522f1]
> /usr/lib/i386-linux-gnu/libstdc++.so.6(_ZdlPv+0x18)[0xb6ba9d88]
> /usr/lib/libgdal.so.1(_ZN15GDALMajorObjectD0Ev+0x22)[0xb075a582]
> /usr/lib/libgdal.so.1(GDALClose+0x77)[0xb074d747]
> /usr/lib/qgis/plugins/libgdalprovider.so(+0xa930)[0xa4888930]
> /usr/lib/qgis/plugins/libgdalprovider.so(+0xaafa)[0xa4888afa]
> /usr/lib/libqgis_core.so.2.18.3(_ZN13QgsRasterPipeD1Ev+0x75)[0xb3d6a7d5]
> /usr/lib/libqgis_core.so.2.18.3(_ZN14QgsRasterLayerD1Ev+0x2f)[0xb3d5cd0f]
> /usr/lib/python2.7/dist-packages/qgis/_core.i386-linux-gnu.so(_ZN17sipQgsRasterLayerD1Ev+0x3b)[0xb489dd2b]
> /usr/lib/python2.7/dist-packages/qgis/_core.i386-linux-gnu.so(_ZN17sipQgsRasterLayerD0Ev+0x1a)[0xb489dd5a]
> /usr/lib/python2.7/dist-packages/qgis/_core.i386-linux-gnu.so(+0x43df45)[0xb4883f45]
> /usr/lib/python2.7/dist-packages/qgis/_core.i386-linux-gnu.so(+0x43df8a)[0xb4883f8a]
> /usr/lib/python2.7/dist-packages/sip.i386-linux-gnu.so(+0x5d49)[0xb724dd49]
> /usr/lib/python2.7/dist-packages/sip.i386-linux-gnu.so(+0xc19b)[0xb725419b]
> /usr/bin/python2.7[0x8144aad]
> /usr/bin/python2.7[0x80fd127]
> /usr/bin/python2.7(PyDict_SetItem+0x478)[0x80e9268]
> /usr/bin/python2.7(_PyModule_Clear+0xba)[0x8149a1a]
> /usr/bin/python2.7(PyImport_Cleanup+0x37a)[0x81495ca]
> /usr/bin/python2.7(Py_Finalize+0x99)[0x8147399]
> /usr/bin/python2.7(Py_Main+0x4bd)[0x80e639d]
> /usr/bin/python2.7(main+0x26)[0x80e5ec6]
> /lib/i386-linux-gnu/libc.so.6(__libc_start_main+0xf7)[0xb75fc637]
> /usr/bin/python2.7[0x80e5dc8]
[snip]

It looks like a bug in an extension, possibly in libgdal, qgis or 
libqgis. It has written to a part of the heap that it shouldn't, perhaps 
beyond the end of an allocated block, corrupting the heap in the process.



From saxri89 at gmail.com  Thu Jan 19 19:53:37 2017
From: saxri89 at gmail.com (Xristos Xristoou)
Date: Thu, 19 Jan 2017 16:53:37 -0800 (PST)
Subject: python corrupted double-linked list error
In-Reply-To: <mailman.26.1484872533.9761.python-list@python.org>
References: <d084e8cc-06df-46dd-8b5e-5d516bb115ab@googlegroups.com>
 <755b72f0-e388-7fa3-a29c-1660b3594298@mrabarnett.plus.com>
 <mailman.26.1484872533.9761.python-list@python.org>
Message-ID: <c27e0803-9fd5-4aa1-9ed7-9b341f90ad7d@googlegroups.com>



how to understand that ?solution ?


From torriem at gmail.com  Thu Jan 19 20:22:08 2017
From: torriem at gmail.com (Michael Torrie)
Date: Thu, 19 Jan 2017 18:22:08 -0700
Subject: python corrupted double-linked list error
In-Reply-To: <c27e0803-9fd5-4aa1-9ed7-9b341f90ad7d@googlegroups.com>
References: <d084e8cc-06df-46dd-8b5e-5d516bb115ab@googlegroups.com>
 <755b72f0-e388-7fa3-a29c-1660b3594298@mrabarnett.plus.com>
 <mailman.26.1484872533.9761.python-list@python.org>
 <c27e0803-9fd5-4aa1-9ed7-9b341f90ad7d@googlegroups.com>
Message-ID: <d1b6fda5-52d8-7da1-d912-7113fdbcded1@gmail.com>

On 01/19/2017 05:53 PM, Xristos Xristoou wrote:
> 
> 
> how to understand that ?solution ?

Well the problem is likely in the gdal or/and qgis modules. You'll
probably want to talk to the qgis folks about this problem.  It's not a
bug in Python itself.

If you can reproduce the problem with a minimal script, you can post it
here and maybe someone can help here.



From Cecil at decebal.nl  Thu Jan 19 23:26:20 2017
From: Cecil at decebal.nl (Cecil Westerhof)
Date: Fri, 20 Jan 2017 05:26:20 +0100
Subject: Using python to start programs after logging in
References: <878tq6amvj.fsf@Equus.decebal.nl>
 <a26a0a12-c8b3-de15-4f54-dfb138cee56a@mrabarnett.plus.com>
 <mailman.21.1484856755.9761.python-list@python.org>
 <87ziimg2yw.fsf@Equus.decebal.nl> <87shoefwqe.fsf@Equus.decebal.nl>
 <bb527e0a-4d77-8f20-e6c1-a07da10b3f1d@mrabarnett.plus.com>
 <mailman.25.1484871893.9761.python-list@python.org>
Message-ID: <878tq65pcj.fsf@Equus.decebal.nl>

On Friday 20 Jan 2017 01:24 CET, MRAB wrote:

>> I wrote a function for switching to the correct virtual desktop and
>> starting all the commands. I am also using with now:
>> def do_desktop(desktop, commands, seconds_to_wait = 10):
>> desktop_command = ('wmctrl -s ' + desktop).split()
>> check_call(tuple(desktop_command))
>
> You don't have to pass a tuple to check_call; it'll also accept a
> list.

I did not know that. The same for Popen.


>> for command_arr in commands:
>> command         = command_arr[0].split()
>> log_directory   = command_arr[1]
>> directory       = command_arr[2]
>> if (directory != ''):
>> chdir(directory)
>
> There's no need for the parentheses around the 'if' condition.

Thanks, I always thought these were necessary.


>> if (log_directory == 'NONE'):
>> Popen(tuple(command.split()))
>> else:
>> log_file_name = log_directory.replace('%T', strftime('%F_%R'))
>> with open(log_file_name, 'w') as log_file:
>> Popen(tuple(command), stdout = log_file, stderr = STDOUT)
>> if (directory != ''):
>> set_default_dir()
>
> Using 'chdir' is generally a bad idea.
>
> 'Popen' will start the process and then continue, so what you're
> doing is changing the directory, starting a process, and then
> changing the directory again, possibly before the process has truly
> started (i.e. you've told the OS to start it, but there might be a
> small delay before that happens). Popen accepts a 'cwd' argument,
> which sets the 'current working directory' for that process.

I am using cwd now.


>> Sometimes a command needs to be executed in a different directory,
>> that is done like: commands = [ ['lein run', 'NONE',
>> 'Clojure/Quotes'], ['xfce4-terminal --maximize --execute screen -S
>> Clojure -c ~/.screenrcClojure', 'NONE', ''],
>> ]
>> do_desktop('6', commands, 30)
>>
> Why 'NONE'? Why not None?

I am using None now.


Thanks.

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof


From Cecil at decebal.nl  Thu Jan 19 23:34:45 2017
From: Cecil at decebal.nl (Cecil Westerhof)
Date: Fri, 20 Jan 2017 05:34:45 +0100
Subject: Using python to start programs after logging in
References: <878tq6amvj.fsf@Equus.decebal.nl>
 <a26a0a12-c8b3-de15-4f54-dfb138cee56a@mrabarnett.plus.com>
 <mailman.21.1484856755.9761.python-list@python.org>
 <87ziimg2yw.fsf@Equus.decebal.nl> <87shoefwqe.fsf@Equus.decebal.nl>
Message-ID: <874m0u5oyi.fsf@Equus.decebal.nl>

On Friday 20 Jan 2017 00:36 CET, Cecil Westerhof wrote:

> I wrote a function for switching to the correct virtual desktop and
> starting all the commands. I am also using with now:
> def do_desktop(desktop, commands, seconds_to_wait = 10):
> desktop_command = ('wmctrl -s ' + desktop).split()
> check_call(tuple(desktop_command))
> for command_arr in commands:
> command         = command_arr[0].split()
> log_directory   = command_arr[1]
> directory       = command_arr[2]
> if (directory != ''):
> chdir(directory)
> if (log_directory == 'NONE'):
> Popen(tuple(command.split()))
> else:
> log_file_name = log_directory.replace('%T', strftime('%F_%R'))
> with open(log_file_name, 'w') as log_file:
> Popen(tuple(command), stdout = log_file, stderr = STDOUT)
> if (directory != ''):
> set_default_dir()
> sleep(seconds_to_wait)


I wrote a little better version:
def do_desktop(desktop, commands, seconds_to_wait):
    desktop_command = (switch_desktop + desktop).split()
    if seconds_to_wait == 0:
        seconds_to_wait = 10
    check_call(desktop_command)
    for command_arr in commands:
        command         = command_arr[0].split()
        log_directory   = command_arr[1]
        directory       = command_arr[2]
        if not log_directory:
            log_directory = '/dev/null'
        log_file_name = log_directory.replace('%T', strftime('%F_%R'))
        with open(log_file_name, 'w') as log_file:
            Popen(command, stdout = log_file, cwd = directory, stderr = STDOUT)
    sleep(seconds_to_wait)

When there is no log_directory I set it to '/dev/null': that makes the
code a little bit cleaner.


And everything is now fetched from the database:
for desktop in cursor.execute(select_desktops).fetchall():
    desktop_name    = desktop[0]
    desktop_value   = desktop[1]
    desktop_wait    = desktop[2]
    commands        = cursor.execute(select_commands, [desktop_name]).fetchall()
    do_desktop(desktop_value, commands, desktop_wait)

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof


From python at deborahswanson.net  Fri Jan 20 04:01:57 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Fri, 20 Jan 2017 01:01:57 -0800
Subject: Must target be only one bit one such as 0001, 0010, 0100,
 1000 In supervised neural learning f(w*p+b) with perceptron rule w =
 w + e for linear case?
In-Reply-To: <f353c219-a7a1-4592-94a4-8387ac254491@googlegroups.com>
Message-ID: <000e01d272fb$db42edc0$27b23dae@sambora>

Ho Yeung Lee wrote, on January 19, 2017 12:05 AM
> 
> Must target be only one bit one such as 0001,0010,0100,1000 
> In supervised neural learning f(w*p+b) with perceptron rule w 
> = w + e for linear case?
> 
> with neural network design
> 
> does it means that can not use two or more one as target such 
> as 0011,0110,1100,1010, 0111,1110,1101, etc when training weight?

With all respect, this sounds like a question you should be asking your
professor, or one of the teaching assistants (TAs) for the course, or
maybe your local computer science tutoring volunteers, if none of the
above are available.

This list is for questions and discussion about python. Maybe you're
trying to code this problem in python, or maybe you're planning to at
some stage, but you   need to understand the fundamentals of the problem
first.

It's possible someone on this list would recognize the problem you're
having, but it's unlikely.

Come back with a clearly stated python problem, and I'm sure lots of
people would help you with it.

Deborah



From dieter at handshake.de  Fri Jan 20 04:46:14 2017
From: dieter at handshake.de (dieter)
Date: Fri, 20 Jan 2017 10:46:14 +0100
Subject: ipython2 does not work anymore
References: <87bmv3xf5r.fsf@Equus.decebal.nl>
 <35dadf92-ada7-02ce-3449-750cb914c426@mrabarnett.plus.com>
 <mailman.20.1484856523.9761.python-list@python.org>
 <874m0uhhys.fsf@Equus.decebal.nl>
Message-ID: <8737geukrd.fsf@handshake.de>

Cecil Westerhof <Cecil at decebal.nl> writes:
> ...
>> If you do mean 'pathlib', it was introduced in Python 3.4.
>
> It is about python2.

I can remember to have seen announcements for enhanced "path" modules
in this list. Your previously posted traceback shows that the problem
comes from the package "pickleshare" which expects a "path" module
(likely one of those enhanced modules) and cannot find one.

I would try to find out what "path" module "pickleshare" requires
and then install it.



From dieter at handshake.de  Fri Jan 20 04:52:27 2017
From: dieter at handshake.de (dieter)
Date: Fri, 20 Jan 2017 10:52:27 +0100
Subject: python corrupted double-linked list error
References: <d084e8cc-06df-46dd-8b5e-5d516bb115ab@googlegroups.com>
Message-ID: <87y3y6t5wk.fsf@handshake.de>

Xristos Xristoou <saxri89 at gmail.com> writes:

> i am a python 2.7 and ubuntu 16.04 user.

While analysing a problem upgrading to Ubuntu 16.04 (unrelated to Python)
I found messages reporting about a problem with Python an Ubuntu 16.04[.0]
(leading to memory corruption - something you are seeing).
The proposed solution has been to upgrade to Ubuntu 16.04.1.



From gordon at panix.com  Fri Jan 20 12:46:00 2017
From: gordon at panix.com (John Gordon)
Date: Fri, 20 Jan 2017 17:46:00 +0000 (UTC)
Subject: Using python to start programs after logging in
References: <878tq6amvj.fsf@Equus.decebal.nl> <o5r421$5b$1@reader1.panix.com>
 <878tq6hi0s.fsf@Equus.decebal.nl>
Message-ID: <o5ticn$8r1$1@reader1.panix.com>

In <878tq6hi0s.fsf at Equus.decebal.nl> Cecil Westerhof <Cecil at decebal.nl> writes:

> > I think using your window manager's built-in facilities for starting
> > programs would be better.  Why are you using Python instead?

> Because when you use the window managers builtin facilities then all
> programs will be started on the same virtual desktop and I want to
> start them on different ones.

The window manager doesn't allow you to specify a target desktop?  That
seems like a pretty heinous feature omission.

-- 
John Gordon                   A is for Amy, who fell down the stairs
gordon at panix.com              B is for Basil, assaulted by bears
                                -- Edward Gorey, "The Gashlycrumb Tinies"



From petef4+usenet at gmail.com  Fri Jan 20 17:35:02 2017
From: petef4+usenet at gmail.com (Pete Forman)
Date: Fri, 20 Jan 2017 22:35:02 +0000
Subject: PEP 393 vs UTF-8 Everywhere
Message-ID: <m1d1fh4ay1.fsf@iKarel.lan>

Can anyone point me at a rationale for PEP 393 being incorporated in
Python 3.3 over using UTF-8 as an internal string representation? I've
found good articles by Nick Coghlan, Armin Ronacher and others on the
matter. What I have not found is discussion of pros and cons of
alternatives to the old narrow or wide implementation of Unicode
strings.

ISTM that most operations on strings are via iterators and thus agnostic
to variable or fixed width encodings. How important is it to be able to
get to part of a string with a simple index? Just because old skool
strings could be treated as a sequence of characters, is that a reason
to shoehorn the subtleties of Unicode into that model?

-- 
Pete Forman


From ckaynor at zindagigames.com  Fri Jan 20 18:06:24 2017
From: ckaynor at zindagigames.com (Chris Kaynor)
Date: Fri, 20 Jan 2017 15:06:24 -0800
Subject: PEP 393 vs UTF-8 Everywhere
In-Reply-To: <m1d1fh4ay1.fsf@iKarel.lan>
References: <m1d1fh4ay1.fsf@iKarel.lan>
Message-ID: <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>

On Fri, Jan 20, 2017 at 2:35 PM, Pete Forman <petef4+usenet at gmail.com> wrote:
> Can anyone point me at a rationale for PEP 393 being incorporated in
> Python 3.3 over using UTF-8 as an internal string representation? I've
> found good articles by Nick Coghlan, Armin Ronacher and others on the
> matter. What I have not found is discussion of pros and cons of
> alternatives to the old narrow or wide implementation of Unicode
> strings.

The PEP itself has the rational for the problems with the narrow/wide
idea, the quote from https://www.python.org/dev/peps/pep-0393/:
There are two classes of complaints about the current implementation
of the unicode type:on systems only supporting UTF-16, users complain
that non-BMP characters are not properly supported. On systems using
UCS-4 internally (and also sometimes on systems using UCS-2), there is
a complaint that Unicode strings take up too much memory - especially
compared to Python 2.x, where the same code would often use ASCII
strings (i.e. ASCII-encoded byte strings). With the proposed approach,
ASCII-only Unicode strings will again use only one byte per character;
while still allowing efficient indexing of strings containing non-BMP
characters (as strings containing them will use 4 bytes per
character).

Basically, narrow builds had very odd behavior with non-BMP
characters, namely that indexing into the string could easily produce
mojibake. Wide builds used quite a bit more memory, which generally
translates to reduced performance.

> ISTM that most operations on strings are via iterators and thus agnostic
> to variable or fixed width encodings. How important is it to be able to
> get to part of a string with a simple index? Just because old skool
> strings could be treated as a sequence of characters, is that a reason
> to shoehorn the subtleties of Unicode into that model?

I think you are underestimating the indexing usages of strings. Every
operation on a string using UTF8 that contains larger characters must
be completed by starting at index 0 - you can never start anywhere
else safely. rfind/rsplit/rindex/rstrip and the other related reverse
functions would require walking the string from start to end, rather
than short-circuiting by reading from right to left. With indexing
becoming linear time, many simple algorithms need to be written with
that in mind, to avoid n*n time. Such performance regressions can
often go unnoticed by developers, who are likely to be testing with
small data, and thus may cause (accidental) DOS attacks when used on
real data. The exact same problems occur with the old narrow builds
(UTF16; note that this was NOT implemented in those builds, however,
which caused the mojibake problems) as well - only a UTF32 or PEP393
implementation can avoid those problems.

Note that from a user (including most developers, if not almost all),
PEP393 strings can be treated as if they were UTF32, but with many of
the benefits of UTF8. As far as I'm aware, it is only developers
writing extension modules that need to care - and only then if they
need maximum performance, and thus cannot convert every string they
access to UTF32 or UTF8.

--
Chris Kaynor


From tomuxiong at gmx.com  Fri Jan 20 18:15:50 2017
From: tomuxiong at gmx.com (Thomas Nyberg)
Date: Fri, 20 Jan 2017 15:15:50 -0800
Subject: PEP 393 vs UTF-8 Everywhere
In-Reply-To: <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
Message-ID: <9d3809e3-51e8-5697-a791-dc7f7e7d8bb6@gmx.com>

On 01/20/2017 03:06 PM, Chris Kaynor wrote:
>
> 	[...snip...]
>
> --
> Chris Kaynor
>

I was able to delete my response which was a wholly contained subset of 
this one. :)


But I have one extra question. Is string indexing guaranteed to be 
constant-time for python? I thought so, but I couldn't find it 
documented anywhere. (Not that I think it practically matters, since it 
couldn't really change if it weren't for all the reasons you mentioned.) 
I found this which at details (if not explicitly "guarantees") the 
complexity properties of other datatypes:

https://wiki.python.org/moin/TimeComplexity

Cheers,
Thomas


From rosuav at gmail.com  Fri Jan 20 18:36:03 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 21 Jan 2017 10:36:03 +1100
Subject: PEP 393 vs UTF-8 Everywhere
In-Reply-To: <9d3809e3-51e8-5697-a791-dc7f7e7d8bb6@gmx.com>
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
 <9d3809e3-51e8-5697-a791-dc7f7e7d8bb6@gmx.com>
Message-ID: <CAPTjJmpj=iib7C=cGumzA8rab=9OkB2Osb+NB_YddTCcJCBpsQ@mail.gmail.com>

On Sat, Jan 21, 2017 at 10:15 AM, Thomas Nyberg <tomuxiong at gmx.com> wrote:
> But I have one extra question. Is string indexing guaranteed to be
> constant-time for python? I thought so, but I couldn't find it documented
> anywhere. (Not that I think it practically matters, since it couldn't really
> change if it weren't for all the reasons you mentioned.) I found this which
> at details (if not explicitly "guarantees") the complexity properties of
> other datatypes:
>

No, it isn't; this question came up in the context of MicroPython,
which chose to go UTF-8 internally instead of PEP 393. But the
considerations for uPy are different - it's not designed to handle
gobs of data, so constant-time vs linear isn't going to have as much
impact. But in normal work, it's important enough to have predictable
string performance. You can't afford to deploy a web application, test
it, and then have someone send a large amount of data at it, causing
massive O(n^2) blowouts.

ChrisA


From ckaynor at zindagigames.com  Fri Jan 20 18:37:44 2017
From: ckaynor at zindagigames.com (Chris Kaynor)
Date: Fri, 20 Jan 2017 15:37:44 -0800
Subject: PEP 393 vs UTF-8 Everywhere
In-Reply-To: <9d3809e3-51e8-5697-a791-dc7f7e7d8bb6@gmx.com>
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
 <9d3809e3-51e8-5697-a791-dc7f7e7d8bb6@gmx.com>
Message-ID: <CALvWhxtbLmtmSEXy7U802xQupincS__dzKfz-TOF=XQbJOQQpw@mail.gmail.com>

.
On Fri, Jan 20, 2017 at 3:15 PM, Thomas Nyberg <tomuxiong at gmx.com> wrote:
> On 01/20/2017 03:06 PM, Chris Kaynor wrote:
>>
>>
>>         [...snip...]
>>
>> --
>> Chris Kaynor
>>
>
> I was able to delete my response which was a wholly contained subset of this
> one. :)
>
>
> But I have one extra question. Is string indexing guaranteed to be
> constant-time for python? I thought so, but I couldn't find it documented
> anywhere. (Not that I think it practically matters, since it couldn't really
> change if it weren't for all the reasons you mentioned.) I found this which
> at details (if not explicitly "guarantees") the complexity properties of
> other datatypes:
>
> https://wiki.python.org/moin/TimeComplexity

As far as I'm aware, the language does not guarantee it. In fact, I
believe it was decided that MicroPython could use UTF8 strings with
linear indexing while still calling itself Python. This was very
useful for MicroPython due to the platforms it supports (embedded),
and needing to keep the memory footprint very small.

I believe Guido (on Python-ideas) has stated that constant-time string
indexing is a guarantee of CPython, however.

The only reference I found in my (very quick) search is the Python-Dev
thread at https://groups.google.com/forum/#!msg/dev-python/3lfXwljNLj8/XxO2s0TGYrYJ


From python at mrabarnett.plus.com  Fri Jan 20 19:18:51 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Sat, 21 Jan 2017 00:18:51 +0000
Subject: PEP 393 vs UTF-8 Everywhere
In-Reply-To: <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
Message-ID: <b1b016bc-c9be-05ba-2244-fbe286f8bc46@mrabarnett.plus.com>

On 2017-01-20 23:06, Chris Kaynor wrote:
> On Fri, Jan 20, 2017 at 2:35 PM, Pete Forman <petef4+usenet at gmail.com> wrote:
>> Can anyone point me at a rationale for PEP 393 being incorporated in
>> Python 3.3 over using UTF-8 as an internal string representation? I've
>> found good articles by Nick Coghlan, Armin Ronacher and others on the
>> matter. What I have not found is discussion of pros and cons of
>> alternatives to the old narrow or wide implementation of Unicode
>> strings.
>
> The PEP itself has the rational for the problems with the narrow/wide
> idea, the quote from https://www.python.org/dev/peps/pep-0393/:
> There are two classes of complaints about the current implementation
> of the unicode type:on systems only supporting UTF-16, users complain
> that non-BMP characters are not properly supported. On systems using
> UCS-4 internally (and also sometimes on systems using UCS-2), there is
> a complaint that Unicode strings take up too much memory - especially
> compared to Python 2.x, where the same code would often use ASCII
> strings (i.e. ASCII-encoded byte strings). With the proposed approach,
> ASCII-only Unicode strings will again use only one byte per character;
> while still allowing efficient indexing of strings containing non-BMP
> characters (as strings containing them will use 4 bytes per
> character).
>
> Basically, narrow builds had very odd behavior with non-BMP
> characters, namely that indexing into the string could easily produce
> mojibake. Wide builds used quite a bit more memory, which generally
> translates to reduced performance.
>
>> ISTM that most operations on strings are via iterators and thus agnostic
>> to variable or fixed width encodings. How important is it to be able to
>> get to part of a string with a simple index? Just because old skool
>> strings could be treated as a sequence of characters, is that a reason
>> to shoehorn the subtleties of Unicode into that model?
>
> I think you are underestimating the indexing usages of strings. Every
> operation on a string using UTF8 that contains larger characters must
> be completed by starting at index 0 - you can never start anywhere
> else safely. rfind/rsplit/rindex/rstrip and the other related reverse
> functions would require walking the string from start to end, rather
> than short-circuiting by reading from right to left. With indexing
> becoming linear time, many simple algorithms need to be written with
> that in mind, to avoid n*n time. Such performance regressions can
> often go unnoticed by developers, who are likely to be testing with
> small data, and thus may cause (accidental) DOS attacks when used on
> real data. The exact same problems occur with the old narrow builds
> (UTF16; note that this was NOT implemented in those builds, however,
> which caused the mojibake problems) as well - only a UTF32 or PEP393
> implementation can avoid those problems.
>
You could implement rsplit and rstrip easily enough, but rfind and 
rindex return the index, so you'd need to scan the string to return that.

> Note that from a user (including most developers, if not almost all),
> PEP393 strings can be treated as if they were UTF32, but with many of
> the benefits of UTF8. As far as I'm aware, it is only developers
> writing extension modules that need to care - and only then if they
> need maximum performance, and thus cannot convert every string they
> access to UTF32 or UTF8.
>
As someone who has written an extension, I can tell you that I much 
prefer dealing with a fixed number of bytes per codepoint than a 
variable number of bytes per codepoint, especially as I'm also 
supporting earlier versions of Python where that was the case.



From petef4+usenet at gmail.com  Fri Jan 20 19:30:16 2017
From: petef4+usenet at gmail.com (Pete Forman)
Date: Sat, 21 Jan 2017 00:30:16 +0000
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
 <mailman.33.1484953608.9761.python-list@python.org>
Message-ID: <m160l945lz.fsf@iKarel.lan>

Chris Kaynor <ckaynor at zindagigames.com> writes:

> On Fri, Jan 20, 2017 at 2:35 PM, Pete Forman <petef4+usenet at gmail.com> wrote:
>> Can anyone point me at a rationale for PEP 393 being incorporated in
>> Python 3.3 over using UTF-8 as an internal string representation?
>> I've found good articles by Nick Coghlan, Armin Ronacher and others
>> on the matter. What I have not found is discussion of pros and cons
>> of alternatives to the old narrow or wide implementation of Unicode
>> strings.
>
> The PEP itself has the rational for the problems with the narrow/wide
> idea, the quote from https://www.python.org/dev/peps/pep-0393/: There
> are two classes of complaints about the current implementation of the
> unicode type:on systems only supporting UTF-16, users complain that
> non-BMP characters are not properly supported. On systems using UCS-4
> internally (and also sometimes on systems using UCS-2), there is a
> complaint that Unicode strings take up too much memory - especially
> compared to Python 2.x, where the same code would often use ASCII
> strings (i.e. ASCII-encoded byte strings). With the proposed approach,
> ASCII-only Unicode strings will again use only one byte per character;
> while still allowing efficient indexing of strings containing non-BMP
> characters (as strings containing them will use 4 bytes per
> character).
>
> Basically, narrow builds had very odd behavior with non-BMP
> characters, namely that indexing into the string could easily produce
> mojibake. Wide builds used quite a bit more memory, which generally
> translates to reduced performance.

I'm taking as a given that the old way was often sub-optimal in many
scenarios. My questions were about the alternatives, and why PEP 393 was
chosen over other approaches.

>> ISTM that most operations on strings are via iterators and thus
>> agnostic to variable or fixed width encodings. How important is it to
>> be able to get to part of a string with a simple index? Just because
>> old skool strings could be treated as a sequence of characters, is
>> that a reason to shoehorn the subtleties of Unicode into that model?
>
> I think you are underestimating the indexing usages of strings. Every
> operation on a string using UTF8 that contains larger characters must
> be completed by starting at index 0 - you can never start anywhere
> else safely. rfind/rsplit/rindex/rstrip and the other related reverse
> functions would require walking the string from start to end, rather
> than short-circuiting by reading from right to left. With indexing
> becoming linear time, many simple algorithms need to be written with
> that in mind, to avoid n*n time. Such performance regressions can
> often go unnoticed by developers, who are likely to be testing with
> small data, and thus may cause (accidental) DOS attacks when used on
> real data. The exact same problems occur with the old narrow builds
> (UTF16; note that this was NOT implemented in those builds, however,
> which caused the mojibake problems) as well - only a UTF32 or PEP393
> implementation can avoid those problems.

I was asserting that most useful operations on strings start from index
0. The r* operations would not be slowed down that much as UTF-8 has the
useful property that attempting to interpret from a byte that is not at
the start of a sequence (in the sense of a code point rather than
Python) is invalid and so quick to move over while working backwards
from the end.

The only significant use of an index dereference that I could come up
with was the result of a find() or index(). I put out this public
question so that I could be enclued as to other uses. My personal
experience is that in most cases where I might consider find() that I
end up using re and use the return from match groups which has copies of
the (sub)strings that I want.

> Note that from a user (including most developers, if not almost all),
> PEP393 strings can be treated as if they were UTF32, but with many of
> the benefits of UTF8. As far as I'm aware, it is only developers
> writing extension modules that need to care - and only then if they
> need maximum performance, and thus cannot convert every string they
> access to UTF32 or UTF8.

PEP 393 already says that "the specification chooses UTF-8 as the
recommended way of exposing strings to C code".

-- 
Pete Forman


From petef4+usenet at gmail.com  Fri Jan 20 19:51:53 2017
From: petef4+usenet at gmail.com (Pete Forman)
Date: Sat, 21 Jan 2017 00:51:53 +0000
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
 <b1b016bc-c9be-05ba-2244-fbe286f8bc46@mrabarnett.plus.com>
 <mailman.37.1484957943.9761.python-list@python.org>
Message-ID: <m11svx44ly.fsf@iKarel.lan>

MRAB <python at mrabarnett.plus.com> writes:

> As someone who has written an extension, I can tell you that I much
> prefer dealing with a fixed number of bytes per codepoint than a
> variable number of bytes per codepoint, especially as I'm also
> supporting earlier versions of Python where that was the case.

At the risk of sounding harsh, if supporting variable bytes per
codepoint is a pain you should roll with it for the greater good of
supporting users.

PEP 393 / Python 3.3 required extension writers to revisit their access
to strings. My explicit question was about why PEP 393 was adopted to
replace the deficient old implementations rather than another approach.
The implicit question is whether a UTF-8 internal representation should
replace that of PEP 393.

-- 
Pete Forman


From rosuav at gmail.com  Fri Jan 20 19:58:01 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 21 Jan 2017 11:58:01 +1100
Subject: PEP 393 vs UTF-8 Everywhere
In-Reply-To: <m160l945lz.fsf@iKarel.lan>
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
 <mailman.33.1484953608.9761.python-list@python.org>
 <m160l945lz.fsf@iKarel.lan>
Message-ID: <CAPTjJmqxiATbYAHBA29wiPco1NgCDAUjproeS03yhgtMJNoumw@mail.gmail.com>

On Sat, Jan 21, 2017 at 11:30 AM, Pete Forman <petef4+usenet at gmail.com> wrote:
> I was asserting that most useful operations on strings start from index
> 0. The r* operations would not be slowed down that much as UTF-8 has the
> useful property that attempting to interpret from a byte that is not at
> the start of a sequence (in the sense of a code point rather than
> Python) is invalid and so quick to move over while working backwards
> from the end.

Let's take one very common example: decoding JSON. A ton of web
servers out there will call json.loads() on user-supplied data. The
bulk of the work is in the scanner, which steps through the string and
does the actual parsing. That function is implemented in Python, so
it's a good example. (There is a C accelerator, but we can ignore that
and look at the pure Python one.)

So, how could you implement this function? The current implementation
maintains an index - an integer position through the string. It
repeatedly requests the next character as string[idx], and can also
slice the string (to check for keywords like "true") or use a regex
(to check for numbers). Everything's clean, but it's lots of indexing.
Alternatively, it could remove and discard characters as they're
consumed. It would maintain a string that consists of all the unparsed
characters. All indexing would be at or near zero, but after every
tiny piece of parsing, the string would get sliced.

With immutable UTF-8 strings, both of these would be O(n^2). Either
indexing is linear, so parsing the tail of the string means scanning
repeatedly; or slicing is linear, so parsing the head of the string
means slicing all the rest away.

The only way for it to be fast enough would be to have some sort of
retainable string iterator, which means exposing an opaque "position
marker" that serves no purpose other than parsing. Every string parse
operation would have to be reimplemented this way, lest it perform
abysmally on large strings. It'd mean some sort of magic "thing" that
probably has a reference to the original string, so you don't get the
progressive RAM refunds that slicing gives, and you'd still have to
deal with lots of the other consequences. It's probably doable, but it
would be a lot of pain.

ChrisA


From rosuav at gmail.com  Fri Jan 20 20:00:58 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 21 Jan 2017 12:00:58 +1100
Subject: PEP 393 vs UTF-8 Everywhere
In-Reply-To: <m11svx44ly.fsf@iKarel.lan>
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
 <b1b016bc-c9be-05ba-2244-fbe286f8bc46@mrabarnett.plus.com>
 <mailman.37.1484957943.9761.python-list@python.org>
 <m11svx44ly.fsf@iKarel.lan>
Message-ID: <CAPTjJmpBGHc4DN48NMH2D93Hq6MM9zx4D05HpftDrmWVhg+heQ@mail.gmail.com>

On Sat, Jan 21, 2017 at 11:51 AM, Pete Forman <petef4+usenet at gmail.com> wrote:
> MRAB <python at mrabarnett.plus.com> writes:
>
>> As someone who has written an extension, I can tell you that I much
>> prefer dealing with a fixed number of bytes per codepoint than a
>> variable number of bytes per codepoint, especially as I'm also
>> supporting earlier versions of Python where that was the case.
>
> At the risk of sounding harsh, if supporting variable bytes per
> codepoint is a pain you should roll with it for the greater good of
> supporting users.

That hasn't been demonstrated, though. There's plenty of evidence
regarding cache usage that shows that direct indexing is incredibly
beneficial on large strings. What are the benefits of variable-sized
encodings? AFAIK, the only real benefit is that you can use less
memory for strings that contain predominantly ASCII but a small number
of astral characters (plus *maybe* a faster encode-to-UTF-8; you
wouldn't get a faster decode-from-UTF-8, because you still need to
check that the byte sequence is valid). Can you show a use-case that
would be materially improved by UTF-8?

ChrisA


From python at mrabarnett.plus.com  Fri Jan 20 21:10:15 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Sat, 21 Jan 2017 02:10:15 +0000
Subject: PEP 393 vs UTF-8 Everywhere
In-Reply-To: <m11svx44ly.fsf@iKarel.lan>
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
 <b1b016bc-c9be-05ba-2244-fbe286f8bc46@mrabarnett.plus.com>
 <mailman.37.1484957943.9761.python-list@python.org>
 <m11svx44ly.fsf@iKarel.lan>
Message-ID: <22ab560b-febf-429e-297e-1e41e232da68@mrabarnett.plus.com>

On 2017-01-21 00:51, Pete Forman wrote:
> MRAB <python at mrabarnett.plus.com> writes:
>
>> As someone who has written an extension, I can tell you that I much
>> prefer dealing with a fixed number of bytes per codepoint than a
>> variable number of bytes per codepoint, especially as I'm also
>> supporting earlier versions of Python where that was the case.
>
> At the risk of sounding harsh, if supporting variable bytes per
> codepoint is a pain you should roll with it for the greater good of
> supporting users.
>
Or I could decide not bother and leave it to someone else to continue 
the project. After all, it's not like I'm not getting paid for the work, 
it's purely voluntary.

> PEP 393 / Python 3.3 required extension writers to revisit their access
> to strings. My explicit question was about why PEP 393 was adopted to
> replace the deficient old implementations rather than another approach.
> The implicit question is whether a UTF-8 internal representation should
> replace that of PEP 393.
>
I already had to handle 1-byte bytestrings and 2/4-byte (narrow/wide) 
Unicode strings, so switching to 1/2/4 strings wasn't too bad. Switching 
to a completely different, variable-width system would've been a lot 
more work.



From no.email at nospam.invalid  Sat Jan 21 01:01:09 2017
From: no.email at nospam.invalid (Paul Rubin)
Date: Fri, 20 Jan 2017 22:01:09 -0800
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
 <mailman.33.1484953608.9761.python-list@python.org>
 <m160l945lz.fsf@iKarel.lan>
 <CAPTjJmqxiATbYAHBA29wiPco1NgCDAUjproeS03yhgtMJNoumw@mail.gmail.com>
 <mailman.38.1484960289.9761.python-list@python.org>
Message-ID: <87inp9rly2.fsf@jester.hsd1.ca.comcast.net>

Chris Angelico <rosuav at gmail.com> writes:
> decoding JSON... the scanner, which steps through the string and
> does the actual parsing. ...
> The only way for it to be fast enough would be to have some sort of
> retainable string iterator, which means exposing an opaque "position
> marker" that serves no purpose other than parsing.

Python already has that type of iterator:
   x = "foo"
   for c in x: ....

> It'd mean some sort of magic "thing" that probably has a reference to
> the original string

It's a regular old string iterator unless I'm missing something.  Of
course a json parser should use it, though who uses the non-C json
parser anyway these days?

[Chris Kaynor writes:]
> rfind/rsplit/rindex/rstrip and the other related reverse
> functions would require walking the string from start to end, rather
> than short-circuiting by reading from right to left. 

UTF-8 can be read from right to left because you can recognize when a
codepoint begins by looking at the top 2 bits of each byte as you scan
backwards.  Any combination except for 11 is a leading byte, and 11 is
always a continuation byte.  This "prefix property" of UTF8 is a design
feature and not a trick someone noticed after the fact.

Also if you really want O(1) random access, you could put an auxiliary
table into long strings, giving the byte offset of every 256th codepoint
or something like that.  Then you'd go to the nearest table entry and
scan from there.  This would usually be in-cache scanning so quite fast.
Or use the related representation of "ropes" which are also very easy to
concatenate if they can be nested.  Erlang does something like that
with what it calls "binaries".


From rosuav at gmail.com  Sat Jan 21 01:23:02 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 21 Jan 2017 17:23:02 +1100
Subject: PEP 393 vs UTF-8 Everywhere
In-Reply-To: <87inp9rly2.fsf@jester.hsd1.ca.comcast.net>
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
 <mailman.33.1484953608.9761.python-list@python.org>
 <m160l945lz.fsf@iKarel.lan>
 <CAPTjJmqxiATbYAHBA29wiPco1NgCDAUjproeS03yhgtMJNoumw@mail.gmail.com>
 <mailman.38.1484960289.9761.python-list@python.org>
 <87inp9rly2.fsf@jester.hsd1.ca.comcast.net>
Message-ID: <CAPTjJmrKLkQxazVD0RgBjVwz_Y+SiW=MtEpsV2cwL8+XyG9n+A@mail.gmail.com>

On Sat, Jan 21, 2017 at 5:01 PM, Paul Rubin <no.email at nospam.invalid> wrote:
> Chris Angelico <rosuav at gmail.com> writes:
>> decoding JSON... the scanner, which steps through the string and
>> does the actual parsing. ...
>> The only way for it to be fast enough would be to have some sort of
>> retainable string iterator, which means exposing an opaque "position
>> marker" that serves no purpose other than parsing.
>
> Python already has that type of iterator:
>    x = "foo"
>    for c in x: ....
>
>> It'd mean some sort of magic "thing" that probably has a reference to
>> the original string
>
> It's a regular old string iterator unless I'm missing something.  Of
> course a json parser should use it, though who uses the non-C json
> parser anyway these days?

You can't do a look-ahead with a vanilla string iterator. That's
necessary for a lot of parsers.

> Also if you really want O(1) random access, you could put an auxiliary
> table into long strings, giving the byte offset of every 256th codepoint
> or something like that.  Then you'd go to the nearest table entry and
> scan from there.  This would usually be in-cache scanning so quite fast.
> Or use the related representation of "ropes" which are also very easy to
> concatenate if they can be nested.  Erlang does something like that
> with what it calls "binaries".

Yes, which gives a two-level indexing (first find the strand, then the
character), and that's going to play pretty badly with CPU caches. I'd
be curious to know how an alternate Python with that implementation
would actually perform.

ChrisA


From jussi.piitulainen at helsinki.fi  Sat Jan 21 01:38:33 2017
From: jussi.piitulainen at helsinki.fi (Jussi Piitulainen)
Date: Sat, 21 Jan 2017 08:38:33 +0200
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
 <mailman.33.1484953608.9761.python-list@python.org>
 <m160l945lz.fsf@iKarel.lan>
 <CAPTjJmqxiATbYAHBA29wiPco1NgCDAUjproeS03yhgtMJNoumw@mail.gmail.com>
 <mailman.38.1484960289.9761.python-list@python.org>
Message-ID: <lf5o9z0j4t2.fsf@ling.helsinki.fi>

Chris Angelico writes:

> On Sat, Jan 21, 2017 at 11:30 AM, Pete Forman wrote:

>> I was asserting that most useful operations on strings start from
>> index 0. The r* operations would not be slowed down that much as
>> UTF-8 has the useful property that attempting to interpret from a
>> byte that is not at the start of a sequence (in the sense of a code
>> point rather than Python) is invalid and so quick to move over while
>> working backwards from the end.
>
> Let's take one very common example: decoding JSON. A ton of web
> servers out there will call json.loads() on user-supplied data. The
> bulk of the work is in the scanner, which steps through the string and
> does the actual parsing. That function is implemented in Python, so
> it's a good example. (There is a C accelerator, but we can ignore that
> and look at the pure Python one.)
>
> So, how could you implement this function? The current implementation
> maintains an index - an integer position through the string. It
> repeatedly requests the next character as string[idx], and can also
> slice the string (to check for keywords like "true") or use a regex
> (to check for numbers). Everything's clean, but it's lots of indexing.
> Alternatively, it could remove and discard characters as they're
> consumed. It would maintain a string that consists of all the unparsed
> characters. All indexing would be at or near zero, but after every
> tiny piece of parsing, the string would get sliced.
>
> With immutable UTF-8 strings, both of these would be O(n^2). Either
> indexing is linear, so parsing the tail of the string means scanning
> repeatedly; or slicing is linear, so parsing the head of the string
> means slicing all the rest away.
>
> The only way for it to be fast enough would be to have some sort of
> retainable string iterator, which means exposing an opaque "position
> marker" that serves no purpose other than parsing. Every string parse
> operation would have to be reimplemented this way, lest it perform
> abysmally on large strings. It'd mean some sort of magic "thing" that
> probably has a reference to the original string, so you don't get the
> progressive RAM refunds that slicing gives, and you'd still have to
> deal with lots of the other consequences. It's probably doable, but it
> would be a lot of pain.

Julia does this. It has immutable UTF-8 strings, and there is a JSON
parser. The "opaque position marker" is just the byte index. An attempt
to use an invalid index throws an error. A substring type points to an
underlying string. An iterator, called graphemes, even returns
substrings that correspond to what people might consider a character.

I offer Julia as evidence.

My impression is that Julia's UTF-8-based system works and is not a
pain. I wrote a toy function once to access the last line of a large
memory-mapped text file, so I have just this little bit of personal
experience of it, so far. Incidentally, can Python memory-map a UTF-8
file as a string?

http://docs.julialang.org/en/stable/manual/strings/
https://github.com/JuliaIO/JSON.jl


From no.email at nospam.invalid  Sat Jan 21 04:14:20 2017
From: no.email at nospam.invalid (Paul Rubin)
Date: Sat, 21 Jan 2017 01:14:20 -0800
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
 <mailman.33.1484953608.9761.python-list@python.org>
 <m160l945lz.fsf@iKarel.lan>
 <CAPTjJmqxiATbYAHBA29wiPco1NgCDAUjproeS03yhgtMJNoumw@mail.gmail.com>
 <mailman.38.1484960289.9761.python-list@python.org>
 <87inp9rly2.fsf@jester.hsd1.ca.comcast.net>
 <CAPTjJmrKLkQxazVD0RgBjVwz_Y+SiW=MtEpsV2cwL8+XyG9n+A@mail.gmail.com>
 <mailman.0.1484979791.2473.python-list@python.org>
Message-ID: <87efzwsrkj.fsf@jester.hsd1.ca.comcast.net>

Chris Angelico <rosuav at gmail.com> writes:
> You can't do a look-ahead with a vanilla string iterator. That's
> necessary for a lot of parsers.

For JSON?  For other parsers you usually have a tokenizer that reads
characters with maybe 1 char of lookahead.

> Yes, which gives a two-level indexing (first find the strand, then the
> character), and that's going to play pretty badly with CPU caches.

If you're jumping around at random all over the string, you probably
really want a bytearray rather than a unicode string.  If you're
scanning sequentually you won't have to look at the outer table very
often.


From Cecil at decebal.nl  Sat Jan 21 06:30:50 2017
From: Cecil at decebal.nl (Cecil Westerhof)
Date: Sat, 21 Jan 2017 12:30:50 +0100
Subject: Let ipython3 use the latest python3
Message-ID: <87efzwzm39.fsf@Equus.decebal.nl>

I built python3.6, but ipython3 is still using the old one (3.4.5).
How can I make ipython3 use 3.6?

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof


From kwpolska at gmail.com  Sat Jan 21 06:49:38 2017
From: kwpolska at gmail.com (Chris Warrick)
Date: Sat, 21 Jan 2017 12:49:38 +0100
Subject: Let ipython3 use the latest python3
In-Reply-To: <87efzwzm39.fsf@Equus.decebal.nl>
References: <87efzwzm39.fsf@Equus.decebal.nl>
Message-ID: <CAMw+j7L6xG=Sg_t_ipujtJxj=Qa2nC1xfn+J3yZ8X4po0m=eMQ@mail.gmail.com>

On 21 January 2017 at 12:30, Cecil Westerhof <Cecil at decebal.nl> wrote:
> I built python3.6, but ipython3 is still using the old one (3.4.5).
> How can I make ipython3 use 3.6?

All packages you have installed are tied to a specific Python version.
If you want to use IPython with Python 3.6, you need to install it for
that version (most likely, with pip) and make sure there is an
ipython3 executable in your $PATH pointing at 3.6. You don?t need to
remove IPython for 3.4 (but you can if you want to get rid of it).

-- 
Chris Warrick <https://chriswarrick.com/>
PGP: 5EAAEA16


From Cecil at decebal.nl  Sat Jan 21 06:56:28 2017
From: Cecil at decebal.nl (Cecil Westerhof)
Date: Sat, 21 Jan 2017 12:56:28 +0100
Subject: Problems with python3.6 on one system, but OK on another
Message-ID: <87a8akzkwj.fsf@Equus.decebal.nl>

I build python3.6 on two systems. On one system everything is OK:
Python 3.6.0 (default, Jan 21 2017, 11:19:56) 
[GCC 4.9.2] on linux
Type "help", "copyright", "credits" or "license" for more information.


But on another I get:
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Python 3.6.0 (default, Jan 21 2017, 12:20:38) 
[GCC 4.8.5] on linux
Type "help", "copyright", "credits" or "license" for more information.

Probably not a big problem, but just wondering what is happening here.
On both systems PYTHONHOME is not set and with the old version (3.4.5)
I did/do not get this message.


Another is that I used PYTHONSTARTUP to point to the following script:
    # startup script for python to enable saving of interpreter history and
    # enabling name completion

    # import needed modules
    import atexit
    import os
    import readline
    import rlcompleter

    # where is history saved
    historyPath = os.path.expanduser("~/.pyhistory")

    # handler for saving history
    def save_history(historyPath=historyPath):
        import readline
        try:
            readline.write_history_file(historyPath)
        except:
            pass

    # read history, if it exists
    if os.path.exists(historyPath):
        readline.set_history_length(10000)
        readline.read_history_file(historyPath)

    # register saving handler
    atexit.register(save_history)

    # enable completion
    readline.parse_and_bind('tab: complete')

    # cleanup
    del os, atexit, readline, rlcompleter, save_history, historyPath


This works with 3.4.5, but with 3.6 it gives:
Traceback (most recent call last):
  File "/etc/pythonstart", line 7, in <module>
    import readline
ModuleNotFoundError: No module named 'readline'


Probably not a big problem because I will mostly work with ipython3 at
the moment I get it working with 3.6, but just wondering.

By the way all other import (including rlcompleter) do work in 3.6.

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof


From python.list at tim.thechases.com  Sat Jan 21 07:45:46 2017
From: python.list at tim.thechases.com (Tim Chase)
Date: Sat, 21 Jan 2017 06:45:46 -0600
Subject: PEP 393 vs UTF-8 Everywhere
In-Reply-To: <CAPTjJmqxiATbYAHBA29wiPco1NgCDAUjproeS03yhgtMJNoumw@mail.gmail.com>
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
 <mailman.33.1484953608.9761.python-list@python.org>
 <m160l945lz.fsf@iKarel.lan>
 <CAPTjJmqxiATbYAHBA29wiPco1NgCDAUjproeS03yhgtMJNoumw@mail.gmail.com>
Message-ID: <20170121064546.0eba2e4c@bigbox.christie.dr>

On 2017-01-21 11:58, Chris Angelico wrote:
> So, how could you implement this function? The current
> implementation maintains an index - an integer position through the
> string. It repeatedly requests the next character as string[idx],
> and can also slice the string (to check for keywords like "true")
> or use a regex (to check for numbers). Everything's clean, but it's
> lots of indexing.

But in these parsing cases, the indexes all originate from stepping
through the string from the beginning and processing it
codepointwise.  Even this is a bit of an oddity, especially once you
start taking combining characters into consideration and need to
process them with the preceding character(s).  So while you may be
doing indexing, those indexes usually stem from having walked to that
point, not arbitrarily picking some offset.

You allude to it in your:

> The only way for it to be fast enough would be to have some sort of
> retainable string iterator, which means exposing an opaque "position
> marker" that serves no purpose other than parsing. Every string
> parse operation would have to be reimplemented this way, lest it
> perform abysmally on large strings. It'd mean some sort of magic
> "thing" that probably has a reference to the original string, so
> you don't get the progressive RAM refunds that slicing gives, and
> you'd still have to deal with lots of the other consequences. It's
> probably doable, but it would be a lot of pain.

but I'm hard-pressed to come up with any use case where direct
indexing into a (non-byte)string makes sense unless you've already
processed/searched up to that point and can use a recorded index
from that processing/search.

Can you provide real-world examples of "I need character 2832 from
this string of unicode text, but I never had to scan to that point
linearly from the beginning/end of the string"?

-tkc





From steve+python at pearwood.info  Sat Jan 21 08:56:03 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Sun, 22 Jan 2017 00:56:03 +1100
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
Message-ID: <58836875$0$1600$c3e8da3$5496439d@news.astraweb.com>

On Sat, 21 Jan 2017 09:35 am, Pete Forman wrote:

> Can anyone point me at a rationale for PEP 393 being incorporated in
> Python 3.3 over using UTF-8 as an internal string representation?

I've read over the PEP, and the email discussion, and there is very little
mention of UTF-8, and as far as I can see no counter-proposal for using
UTF-8. However, there are a few mentions of UTF-8 that suggest that the
participants were aware of it as an alternative, and simply didn't think it
was worth considering. I don't know why.

You can read the PEP and the mailing list discussion here:

The PEP:

https://www.python.org/dev/peps/pep-0393/

Mailing list discussion starts here:

https://mail.python.org/pipermail/python-dev/2011-January/107641.html

Stefan Behnel (author of Cython) states that UTF-8 is much harder to use:

https://mail.python.org/pipermail/python-dev/2011-January/107739.html

I see nobody challenging that claim, so perhaps there was simply enough
broad agreement that UTF-8 would have been more work and so nobody wanted
to propose it. I'm just guessing though.

Perhaps it would have been too big a change to adapt the CPython internals
to variable-width UTF-8 from the existing fixed-width UTF-16 and UTF-32
implementations?

(I know that UTF-16 is actually variable-width, but Python prior to PEP 393
treated it as if it were fixed.)

There was a much earlier discussion about the internal implementation of
Unicode strings:

https://mail.python.org/pipermail/python-3000/2006-September/003795.html

including some discussion of UTF-8:

https://mail.python.org/pipermail/python-3000/2006-September/003816.html

It too proposed using a three-way internal implementation, and made it clear
that O(1) indexing was an requirement.

Here's a comment explicitly pointing out that constant-time indexing is
wanted, and that using UTF-8 with a two-level table destroys any space
advantage UTF-8 might have:

https://mail.python.org/pipermail/python-3000/2006-September/003822.html

Ironically, Martin v. L?wis, the author of PEP 393 originally started off
opposing an three-way internal representation, calling it "terrible":

https://mail.python.org/pipermail/python-3000/2006-September/003891.html

Another factor which I didn't see discussed anywhere is that Python strings
treat surrogates as normal code points. I believe that would be troublesome
for a UTF-8 implementation:

py> '\uDC37'.encode('utf-8')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
UnicodeEncodeError: 'utf-8' codec can't encode character '\udc37' in
position 0: surrogates not allowed


but of course with a UCS-2 or UTF-32 implementation it is trivial: you just
treat the surrogate as another code point like any other.


[...]
> ISTM that most operations on strings are via iterators and thus agnostic
> to variable or fixed width encodings. 

Slicing is not.

start = text.find(":")
end = text.rfind("!")
assert end > start
chunk = text[start:end]

But even with iteration, we still would expect that indexes be consecutive:

for i, c in enumerate(text):
    assert c == text[i]


The complexity of those functions will be greatly increased with UTF-8. Of
course you can make it work, and you can even hide the fact that UTF-8 has
variable-width code points. But you can't have all three of:

- simplicity;
- memory efficiency;
- O(1) operations

with UTF-8.

But of course, I'd be happy for a competing Python implementation to use
UTF-8 and prove me wrong!




-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From steve+python at pearwood.info  Sat Jan 21 09:44:30 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Sun, 22 Jan 2017 01:44:30 +1100
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
 <mailman.33.1484953608.9761.python-list@python.org>
 <m160l945lz.fsf@iKarel.lan>
 <CAPTjJmqxiATbYAHBA29wiPco1NgCDAUjproeS03yhgtMJNoumw@mail.gmail.com>
 <20170121064546.0eba2e4c@bigbox.christie.dr>
 <mailman.2.1485003269.2473.python-list@python.org>
Message-ID: <588373cf$0$1602$c3e8da3$5496439d@news.astraweb.com>

On Sat, 21 Jan 2017 11:45 pm, Tim Chase wrote:

> but I'm hard-pressed to come up with any use case where direct
> indexing into a (non-byte)string makes sense unless you've already
> processed/searched up to that point and can use a recorded index
> from that processing/search.


Let's take a simple example: you do a find to get an offset, and then slice
from that offset.

py> text = "??????xx"
py> offset = text.find("?")
py> stuff = text[offset:]
py> assert stuff == "?xx"


That works fine whether indexing refers to code points or bytes.

py> "??????xx".find("?")
5
py> "??????xx".encode('utf-8').find("?".encode('utf-8'))
10

Either way, you get the expected result. However:

py> stuff = text[offset + 1:]
py> assert stuff == "xx"


That requires indexes to point to the beginning of *code points*, not bytes:
taking byte 11 of "??????xx".encode('utf-8') drops you into the middle of
the ? representation:

py> "??????xx".encode('utf-8')[11:]
b'\x84xx'

and it isn't a valid UTF-8 substring. Slicing would generate an exception
unless you happened to slice right at the start of a code point.

It's like seek() and tell() on text files: you cannot seek to arbitrary
positions, but only to the opaque positions returned by tell. That's
unacceptable for strings.

You could avoid that error by increasing the offset by the right amount:

stuff = text[offset + len("?".encode('utf-8'):]

which is awful. I believe that's what Go and Julia expect you to do.

Another solution would be to have the string slicing method automatically
scan forward to the start of the next valid UTF-8 code point. That would be
the "Do What I Mean" solution.

The problem with the DWIM solution is that not only is it adding complexity,
but it's frankly *weird*. It would mean:


- if the character at position `offset` fits in 2 bytes:
  text[offset+1:] == text[offset+2:]

- if it fits in 3 bytes:
  text[offset+1:] == text[offset+2:] == text[offset+3:]

- and if it fits in 4 bytes:
  text[offset+1:] == text[offset+2:] == text[offset+3:] == text[offset+4:]


Having the string slicing method Do The Right Thing would actually be The
Wrong Thing. It would make it awful to reason about slicing.

You can avoid this by having the interpreter treat the Python-level indexes
as opaque "code point offsets", and converting them to and from "byte
offsets" as needed. That's not even very hard. But it either turns every
indexing into O(N) (since you have to walk the string to count which byte
represents the nth code point), or you have to keep an auxiliary table with
every string, letting you convert from byte indexes to code point indexes
quickly, but that will significantly increase the memory size of every
string, blowing out the advantage of using UTF-8 in the first place.



-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From petef4+usenet at gmail.com  Sat Jan 21 10:50:40 2017
From: petef4+usenet at gmail.com (Pete Forman)
Date: Sat, 21 Jan 2017 15:50:40 +0000
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <58836875$0$1600$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <m1wpdo2yzz.fsf@iKarel.lan>

Steve D'Aprano <steve+python at pearwood.info> writes:

> [...]
> Another factor which I didn't see discussed anywhere is that Python
> strings treat surrogates as normal code points. I believe that would
> be troublesome for a UTF-8 implementation:
>
> py> '\uDC37'.encode('utf-8')
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> UnicodeEncodeError: 'utf-8' codec can't encode character '\udc37' in
> position 0: surrogates not allowed
>
> but of course with a UCS-2 or UTF-32 implementation it is trivial: you
> just treat the surrogate as another code point like any other.

Thanks for a very thorough reply, most useful. I'm going to pick you up
on the above, though.

Surrogates only exist in UTF-16. They are expressly forbidden in UTF-8
and UTF-32. The rules for UTF-8 were tightened up in Unicode 4 and RFC
3629 (2003). There is CESU-8 if you really need a naive encoding of
UTF-16 to UTF-8-alike.

py> low = '\uDC37'

is only meaningful on narrow builds pre Python 3.3 where the user must
do extra to correctly handle characters outside the BMP.

-- 
Pete Forman
https://payg-petef.rhcloud.com


From jussi.piitulainen at helsinki.fi  Sat Jan 21 10:56:35 2017
From: jussi.piitulainen at helsinki.fi (Jussi Piitulainen)
Date: Sat, 21 Jan 2017 17:56:35 +0200
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
 <mailman.33.1484953608.9761.python-list@python.org>
 <m160l945lz.fsf@iKarel.lan>
 <CAPTjJmqxiATbYAHBA29wiPco1NgCDAUjproeS03yhgtMJNoumw@mail.gmail.com>
 <20170121064546.0eba2e4c@bigbox.christie.dr>
 <mailman.2.1485003269.2473.python-list@python.org>
 <588373cf$0$1602$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <lf5inp8iez0.fsf@ling.helsinki.fi>

Steve D'Aprano writes:

[snip]

> You could avoid that error by increasing the offset by the right
> amount:
>
> stuff = text[offset + len("?".encode('utf-8'):]
>
> which is awful. I believe that's what Go and Julia expect you to do.

Julia provides a method to get the next index.

let text = "??? ?????? ??????", offset = 1
    while offset <= endof(text)
        print(text[offset], ".")
        offset = nextind(text, offset)
    end
    println()
end # prints: ?.?.?. .?.?.?.?.?.?. .?.?.?.?.?.?.


From rosuav at gmail.com  Sat Jan 21 11:18:03 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 22 Jan 2017 03:18:03 +1100
Subject: PEP 393 vs UTF-8 Everywhere
In-Reply-To: <lf5inp8iez0.fsf@ling.helsinki.fi>
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
 <mailman.33.1484953608.9761.python-list@python.org>
 <m160l945lz.fsf@iKarel.lan>
 <CAPTjJmqxiATbYAHBA29wiPco1NgCDAUjproeS03yhgtMJNoumw@mail.gmail.com>
 <20170121064546.0eba2e4c@bigbox.christie.dr>
 <mailman.2.1485003269.2473.python-list@python.org>
 <588373cf$0$1602$c3e8da3$5496439d@news.astraweb.com>
 <lf5inp8iez0.fsf@ling.helsinki.fi>
Message-ID: <CAPTjJmqvdJqQm-2-dwwZKnemi7ie2t5TT0A+fgPb9ynJ0Ex04g@mail.gmail.com>

On Sun, Jan 22, 2017 at 2:56 AM, Jussi Piitulainen
<jussi.piitulainen at helsinki.fi> wrote:
> Steve D'Aprano writes:
>
> [snip]
>
>> You could avoid that error by increasing the offset by the right
>> amount:
>>
>> stuff = text[offset + len("?".encode('utf-8'):]
>>
>> which is awful. I believe that's what Go and Julia expect you to do.
>
> Julia provides a method to get the next index.
>
> let text = "??? ?????? ??????", offset = 1
>     while offset <= endof(text)
>         print(text[offset], ".")
>         offset = nextind(text, offset)
>     end
>     println()
> end # prints: ?.?.?. .?.?.?.?.?.?. .?.?.?.?.?.?.

This implies that regular iteration isn't good enough, though.

Here's a function that creates a numbered list:

def print_list(items):
    width = len(str(len(items)))
    for idx, item in enumerate(items, 1):
        print("%*d: %s" % (width, idx, item))

In Python, this will happily accept anything that is iterable and has
a known length. Could be a list or tuple, obviously, but can also just
as easily be a dict view (keys or items), a range object, or.... a
string. It's perfectly acceptable to enumerate the characters of a
string. And enumerate() itself is implemented entirely generically. If
you have to call nextind() to get the next character, you've made it
impossible to do any kind of generic operation on the text. You can't
do a windowed view by slicing while iterating, you can't have a "lag"
or "lead" value, you can't do any of those kinds of simple and obvious
index-based operations.

Oh, and Python 3.3 wasn't the first programming language to use this
flexible string representation. Pike introduced an extremely similar
string representation back in 1998:

https://github.com/pikelang/Pike/commit/db4a4

So yes, UTF-8 has its advantages. But it also has its costs, and for a
text processing language like Pike or Python, they significantly
outweigh the benefits.

ChrisA


From jussi.piitulainen at helsinki.fi  Sat Jan 21 13:54:02 2017
From: jussi.piitulainen at helsinki.fi (Jussi Piitulainen)
Date: Sat, 21 Jan 2017 20:54:02 +0200
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
 <mailman.33.1484953608.9761.python-list@python.org>
 <m160l945lz.fsf@iKarel.lan>
 <CAPTjJmqxiATbYAHBA29wiPco1NgCDAUjproeS03yhgtMJNoumw@mail.gmail.com>
 <20170121064546.0eba2e4c@bigbox.christie.dr>
 <mailman.2.1485003269.2473.python-list@python.org>
 <588373cf$0$1602$c3e8da3$5496439d@news.astraweb.com>
 <lf5inp8iez0.fsf@ling.helsinki.fi>
 <CAPTjJmqvdJqQm-2-dwwZKnemi7ie2t5TT0A+fgPb9ynJ0Ex04g@mail.gmail.com>
 <mailman.3.1485015487.2473.python-list@python.org>
Message-ID: <lf5efzwi6r9.fsf@ling.helsinki.fi>

Chris Angelico writes:

> On Sun, Jan 22, 2017 at 2:56 AM, Jussi Piitulainen wrote:
>> Steve D'Aprano writes:
>>
>> [snip]
>>
>>> You could avoid that error by increasing the offset by the right
>>> amount:
>>>
>>> stuff = text[offset + len("?".encode('utf-8'):]
>>>
>>> which is awful. I believe that's what Go and Julia expect you to do.
>>
>> Julia provides a method to get the next index.
>>
>> let text = "??? ?????? ??????", offset = 1
>>     while offset <= endof(text)
>>         print(text[offset], ".")
>>         offset = nextind(text, offset)
>>     end
>>     println()
>> end # prints: ?.?.?. .?.?.?.?.?.?. .?.?.?.?.?.?.
>
> This implies that regular iteration isn't good enough, though.

It doesn't. Here's the straightforward iteration over the whole string:

let text = "??? ?????? ??????"
    for c in text
        print(c, ".")
    end
    println()
end # prints: ?.?.?. .?.?.?.?.?.?. .?.?.?.?.?.?.

One can also join any iterable whose elements can be converted to
strings, and characters can:

let text = "??? ?????? ??????"
    println(join(text, "."), ".")
end # prints: ?.?.?. .?.?.?.?.?.?. .?.?.?.?.?.?.

And strings, trivially, can:

let text = "??? ?????? ??????"
    println(join(split(text), "."), ".")
end # prints: ???.??????.??????.

> Here's a function that creates a numbered list:
>
> def print_list(items):
>     width = len(str(len(items)))
>     for idx, item in enumerate(items, 1):
>         print("%*d: %s" % (width, idx, item))
>
> In Python, this will happily accept anything that is iterable and has
> a known length. Could be a list or tuple, obviously, but can also just
> as easily be a dict view (keys or items), a range object, or.... a
> string. It's perfectly acceptable to enumerate the characters of a
> string. And enumerate() itself is implemented entirely generically.

I'll skip the formatting - I don't know off-hand how to do it - but keep
the width calculation, and I cut the character iterator short at 10
items to save some space. There, it's much the same in Julia:

let text = "??? ?????? ??????"

    function print_list(items)
        width = endof(string(length(items)))
        println("width = ", width)
        for (idx, item) in enumerate(items)
            println(idx, '\t', item)
        end
    end

    print_list(take(text, 10))
    print_list([text, text, text])
    print_list(split(text))
end

That prints this:

width = 2
1	?
2	?
3	?
4	 
5	?
6	?
7	?
8	?
9	?
10	?
width = 1
1	??? ?????? ??????
2	??? ?????? ??????
3	??? ?????? ??????
width = 1
1	???
2	??????
3	??????

> If you have to call nextind() to get the next character, you've made
> it impossible to do any kind of generic operation on the text. You
> can't do a windowed view by slicing while iterating, you can't have a
> "lag" or "lead" value, you can't do any of those kinds of simple and
> obvious index-based operations.

Yet Julia does with ease many things that you seem to think it cannot
possibly do at all. The iteration system works on types that have
methods for certain generic functions. For strings, the default is to
iterate over something like its characters; I think another iterator
over valid indexes is available, or wouldn't be hard to write; it could
be forward or backward, and in Julia many of these things are often
peekable by default (because the iteration protocol itself does not have
state - see below at "more magic").

The usual things work fine:

let text = "??? ?????? ??????"
    foreach(print, enumerate(zip(text, split(text))))
end # prints: (1,('?',"???"))(2,('?',"??????"))(3,('?',"??????"))

How is that bad?

More magic:

let text = "??? ?????? ??????"
    let ever = cycle(split(text))
        println(first(ever))
        println(first(ever))
        for n in 2:6
            println(join(take(ever, n), " "))
end end end

This prints the following. The cycle iterator, ever, produces an
endless repetition of the three words, but it doesn't have state like
Python iterators do, so it's possible to look at the first word twice
(and then five more times).

???
???
??? ??????
??? ?????? ??????
??? ?????? ?????? ???
??? ?????? ?????? ??? ??????
??? ?????? ?????? ??? ?????? ??????

> Oh, and Python 3.3 wasn't the first programming language to use this
> flexible string representation. Pike introduced an extremely similar
> string representation back in 1998:
>
> https://github.com/pikelang/Pike/commit/db4a4

Ok. Is GitHub that old?

> So yes, UTF-8 has its advantages. But it also has its costs, and for a
> text processing language like Pike or Python, they significantly
> outweigh the benefits.

I process text in my work but I really don't use character indexes much
at all. Rather split, join, startswith, endswith, that kind of thing,
and whether a string contains some character or substring anywhere.


From marko at pacujo.net  Sat Jan 21 14:52:42 2017
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sat, 21 Jan 2017 21:52:42 +0200
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <58836875$0$1600$c3e8da3$5496439d@news.astraweb.com>
 <m1wpdo2yzz.fsf@iKarel.lan>
Message-ID: <87o9z0fawl.fsf@elektro.pacujo.net>

Pete Forman <petef4+usenet at gmail.com>:

> Surrogates only exist in UTF-16. They are expressly forbidden in UTF-8
> and UTF-32.

Also, they don't exist as Unicode code points. Python shouldn't allow
surrogate characters in strings.

   Thus the range of code points that are available for use as
   characters is U+0000?U+D7FF and U+E000?U+10FFFF (1,112,064 code
   points).

   <URL: https://en.wikipedia.org/wiki/Unicode>


   The Unicode Character Database is basically a table of characters
   indexed using integers called ?code points?. Valid code points are in
   the ranges 0 to #xD7FF inclusive or #xE000 to #x10FFFF inclusive,
   which is about 1.1 million code points.

   <URL: https://www.gnu.org/software/guile/docs/master/guile.html/Char
   acters.html>

Guile does the right thing:

   scheme@(guile-user)> #\xd7ff
   $1 = #\153777
   scheme@(guile-user)> #\xe000
   $2 = #\160000
   scheme@(guile-user)> #\xd812
   While reading expression:
   ERROR: In procedure scm_lreadr: #<unknown port>:5:8: out-of-range hex c
   haracter escape: xd812

> py> low = '\uDC37'

That should raise a SyntaxError exception.


Marko


From python.list at tim.thechases.com  Sat Jan 21 14:58:46 2017
From: python.list at tim.thechases.com (Tim Chase)
Date: Sat, 21 Jan 2017 13:58:46 -0600
Subject: PEP 393 vs UTF-8 Everywhere
In-Reply-To: <588373cf$0$1602$c3e8da3$5496439d@news.astraweb.com>
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
 <mailman.33.1484953608.9761.python-list@python.org>
 <m160l945lz.fsf@iKarel.lan>
 <CAPTjJmqxiATbYAHBA29wiPco1NgCDAUjproeS03yhgtMJNoumw@mail.gmail.com>
 <20170121064546.0eba2e4c@bigbox.christie.dr>
 <mailman.2.1485003269.2473.python-list@python.org>
 <588373cf$0$1602$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <20170121135846.7b54297b@bigbox.christie.dr>

On 2017-01-22 01:44, Steve D'Aprano wrote:
> On Sat, 21 Jan 2017 11:45 pm, Tim Chase wrote:
> 
> > but I'm hard-pressed to come up with any use case where direct
> > indexing into a (non-byte)string makes sense unless you've already
> > processed/searched up to that point and can use a recorded index
> > from that processing/search.
> 
> 
> Let's take a simple example: you do a find to get an offset, and
> then slice from that offset.
> 
> py> text = "??????xx"
> py> offset = text.find("?")

Right, so here, you've done a (likely linear, but however you get
here) search, which then makes sense to use this opaque "offset"
token for slicing purposes:

> py> stuff = text[offset:]
> py> assert stuff == "?xx"

> That works fine whether indexing refers to code points or bytes.
> 
> py> "??????xx".find("?")
> 5
> py> "??????xx".encode('utf-8').find("?".encode('utf-8'))
> 10
> 
> Either way, you get the expected result. However:
> 
> py> stuff = text[offset + 1:]
> py> assert stuff == "xx"
>
> That requires indexes to point to the beginning of *code points*,
> not bytes: taking byte 11 of "??????xx".encode('utf-8') drops you
> into the middle of the ? representation:
> 
> py> "??????xx".encode('utf-8')[11:]
> b'\x84xx'
> 
> and it isn't a valid UTF-8 substring. Slicing would generate an
> exception unless you happened to slice right at the start of a code
> point.

Right.  It gets even weirder (edge-case'ier) when dealing with
combining characters:


>>> s = "man\N{COMBINING TILDE}ana"
>>> for i, c in enumerate(s): print("%i: %s" % (i, c))
... 
0: m
1: a
2: n
3:?
4: a
5: n
6: a
>>> ''.join(reversed(s))
'an?nam'

Offsetting s[3:] produces a (sub)string that begins with a combining
character that doesn't have anything preceding it to combine with.

> It's like seek() and tell() on text files: you cannot seek to
> arbitrary positions, but only to the opaque positions returned by
> tell. That's unacceptable for strings.

I'm still unclear on *why* this would be considered unacceptable for
strings.  It makes sense when dealing with byte-strings, since they
contain binary data that may need to get sliced at arbitrary
offsets.  But for strings, slicing only makes sense (for every
use-case I've been able to come up with) in the context of known
offsets like you describe with tell().  The cost of not using opaque
tell()like offsets is, as you describe, slicing in the middle of
characters.

> You could avoid that error by increasing the offset by the right
> amount:
> 
> stuff = text[offset + len("?".encode('utf-8'):]
> 
> which is awful. I believe that's what Go and Julia expect you to do.

It may be awful, but only because it hasn't been pythonified.  If the
result from calling .find() on a string returns a "StringOffset"
object, then it would make sense that its __add__/__radd__ methods
would accept an integer and to such translation for you.

> You can avoid this by having the interpreter treat the Python-level
> indexes as opaque "code point offsets", and converting them to and
> from "byte offsets" as needed. That's not even very hard. But it
> either turns every indexing into O(N) (since you have to walk the
> string to count which byte represents the nth code point)

The O(N) cost has to be paid at some point, but I'd put forth that
other operations like .find() already pay that O(N) cost and can
return an opaque "offset token" that can be subsequently used for O(1)
indexing (multiple times if needed).

-tkc














From petef4+usenet at gmail.com  Sat Jan 21 15:21:21 2017
From: petef4+usenet at gmail.com (Pete Forman)
Date: Sat, 21 Jan 2017 20:21:21 +0000
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <58836875$0$1600$c3e8da3$5496439d@news.astraweb.com>
 <m1wpdo2yzz.fsf@iKarel.lan> <87o9z0fawl.fsf@elektro.pacujo.net>
Message-ID: <m1shoc2mgu.fsf@iKarel.lan>

Marko Rauhamaa <marko at pacujo.net> writes:

>> py> low = '\uDC37'
>
> That should raise a SyntaxError exception.

Quite. My point was that with older Python on a narrow build (Windows
and Mac) you need to understand that you are using UTF-16 rather than
Unicode. On a wide build or Python 3.3+ then all is rosy. (At this point
I'm tempted to put in a winky emoji but that might push the internal
representation into UCS-4.)

-- 
Pete Forman


From mruffalo at cs.cmu.edu  Sat Jan 21 15:23:26 2017
From: mruffalo at cs.cmu.edu (Matt Ruffalo)
Date: Sat, 21 Jan 2017 15:23:26 -0500
Subject: PEP 393 vs UTF-8 Everywhere
In-Reply-To: <m1wpdo2yzz.fsf@iKarel.lan>
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <58836875$0$1600$c3e8da3$5496439d@news.astraweb.com>
 <m1wpdo2yzz.fsf@iKarel.lan>
Message-ID: <04a3ca3b-28f5-d2bd-a2ce-fcd1236b3174@cs.cmu.edu>

On 2017-01-21 10:50, Pete Forman wrote:
> Thanks for a very thorough reply, most useful. I'm going to pick you up
> on the above, though.
>
> Surrogates only exist in UTF-16. They are expressly forbidden in UTF-8
> and UTF-32. The rules for UTF-8 were tightened up in Unicode 4 and RFC
> 3629 (2003). There is CESU-8 if you really need a naive encoding of
> UTF-16 to UTF-8-alike.
>
> py> low = '\uDC37'
>
> is only meaningful on narrow builds pre Python 3.3 where the user must
> do extra to correctly handle characters outside the BMP.

Hi Pete-

Lone surrogate characters have a standardized use in Python, not just in
narrow builds of Python <= 3.2. Unpaired high surrogate characters are
used to store any bytes that couldn't be decoded with a given character
encoding scheme, for use in OS/filesystem interfaces that use arbitrary
byte strings:

"""
Python 3.6.0 (default, Dec 23 2016, 08:25:24)
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> s = 'h?llo'
>>> b = s.encode('latin-1')
>>> b
b'h\xe9llo'
>>> from os import fsdecode, fsencode
>>> decoded = fsdecode(b)
>>> decoded
'h\udce9llo'
>>> fsencode(decoded)
b'h\xe9llo'
"""

This provides a mechanism for lossless round-trip decoding and encoding
of arbitrary byte strings which aren't valid under the user's locale.
This is absolutely necessary in POSIX systems in which filenames can
contain any sequence of bytes despite the user's locale, and is even
necessary in Windows, where filenames are stored as opaque
not-quite-UCS2 strings:

"""
Python 3.6.0 (v3.6.0:41df79263a11, Dec 23 2016, 08:06:12) [MSC v.1900 64
bit (AMD64)] on win32
Type "copyright", "credits" or "license()" for more information.
>>> from pathlib import Path
>>> import os
>>> os.chdir(Path('~/Desktop').expanduser())
>>> filename = '\udcf9'
>>> with open(filename, 'w'): pass

>>> os.listdir('.')
['desktop.ini', '\udcf9']
"""

MMR...


From martin.schoon at gmail.com  Sat Jan 21 15:42:29 2017
From: martin.schoon at gmail.com (Martin =?UTF-8?Q?Sch=C3=B6=C3=B6n?=)
Date: 21 Jan 2017 20:42:29 GMT
Subject: Adding colormaps?
References: <eea5oeF2d3aU1@mid.individual.net>
 <P7LgA.125151$Zf5.106498@fx41.am4>
Message-ID: <eehvdlFtgutU1@mid.individual.net>

Den 2017-01-21 skrev Gilmeh Serda <gilmeh.serdah at nothing.here.invalid>:
> On Wed, 18 Jan 2017 21:41:34 +0000, Martin Sch??n wrote:
>
>> What I would like to do is to add the perceptually uniform sequential
>> colormaps introduced in version 1.5.something. I would like to do this
>> without breaking my Debian system in which Matplotlib version 1.4.2 is
>> the newest version available in the repo.
>
> Haven't checked, but I assume you can get the source. Compile it but 
> don't install it and then use the result in virtualenv, maybe?
>
I am hoping for directions to a config file to download and place 
somewhere...

/Martin


From eryksun at gmail.com  Sat Jan 21 15:49:26 2017
From: eryksun at gmail.com (eryk sun)
Date: Sat, 21 Jan 2017 20:49:26 +0000
Subject: PEP 393 vs UTF-8 Everywhere
In-Reply-To: <m1shoc2mgu.fsf@iKarel.lan>
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <58836875$0$1600$c3e8da3$5496439d@news.astraweb.com>
 <m1wpdo2yzz.fsf@iKarel.lan> <87o9z0fawl.fsf@elektro.pacujo.net>
 <m1shoc2mgu.fsf@iKarel.lan>
Message-ID: <CACL+1auxeV=Onh1WYZrvbTubiu=w_B_EftfLW+1HRezo0Jjo1A@mail.gmail.com>

On Sat, Jan 21, 2017 at 8:21 PM, Pete Forman <petef4+usenet at gmail.com> wrote:
> Marko Rauhamaa <marko at pacujo.net> writes:
>
>>> py> low = '\uDC37'
>>
>> That should raise a SyntaxError exception.
>
> Quite. My point was that with older Python on a narrow build (Windows
> and Mac) you need to understand that you are using UTF-16 rather than
> Unicode. On a wide build or Python 3.3+ then all is rosy. (At this point
> I'm tempted to put in a winky emoji but that might push the internal
> representation into UCS-4.)

CPython allows surrogate codes for use with the "surrogateescape" and
"surrogatepass" error handlers, which are used for POSIX and Windows
file-system encoding, respectively. Maybe MicroPython goes about the
file-system round-trip problem differently, or maybe it just require
using bytes for file-system and environment-variable names on POSIX
and doesn't care about Windows.

"surrogateescape" allows 'decoding' arbitrary bytes:

    >>> b'\x81'.decode('ascii', 'surrogateescape')
    '\udc81'
    >>> '\udc81'.encode('ascii', 'surrogateescape')
    b'\x81'

This error handler is required by CPython on POSIX to handle arbitrary
bytes in file-system paths. For example, when running with LANG=C:

    >>> sys.getfilesystemencoding()
    'ascii'
    >>> os.listdir(b'.')
    [b'\x81']
    >>> os.listdir('.')
    ['\udc81']

"surrogatepass" allows encoding surrogates:

    >>> '\udc81'.encode('utf-8', 'surrogatepass')
    b'\xed\xb2\x81'
    >>> b'\xed\xb2\x81'.decode('utf-8', 'surrogatepass')
    '\udc81'

This error handler is used by CPython 3.6+ to encode Windows UCS-2
file-system paths as WTF-8 (Wobbly). For example:

    >>> os.listdir('.')
    ['\udc81']
    >>> os.listdir(b'.')
    [b'\xed\xb2\x81']


From grant.b.edwards at gmail.com  Sat Jan 21 17:28:42 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Sat, 21 Jan 2017 22:28:42 +0000 (UTC)
Subject: How to create a socket.socket() object from a socket fd?
Message-ID: <o60naq$bbm$1@blaine.gmane.org>

Given a Unix file discriptor for an open TCP socket, I can't figure
out how to create a python 2.7 socket object like those returned by
socket.socket() 

Based on the docs, one might think that socket.fromfd() would do that
(since the docs say that's what it does):

Quoting https://docs.python.org/2/library/socket.html

 the socket() function returns a socket object

 [...]  
 
 socket.socket([family[, type[, proto]]])
    Create a new socket using the given address family[...]
 
 [...]
    
 socket.fromfd(fd, family, type[, proto])
    Duplicate the file descriptor fd (an integer as returned by a file
    object?s fileno() method) and build a socket object from the
    result. 

But it doesn't work as described -- the docs apprently use the term
"socket object" to refer to two different things.
    
IOW, a "socket object" is a different type than a "socket object".

Here's what a "socket object" returned by socket.socket() looks like:

  repr(osock):
  <socket._socketobject object at 0x7f701948f520>
  
  dir(osock):
  ['__class__', '__delattr__', '__doc__', '__format__',
  '__getattribute__', '__hash__', '__init__', '__module__', '__new__',
  '__reduce__', '__reduce_ex__', '__repr__', '__setattr__',
  '__sizeof__', '__slots__', '__str__', '__subclasshook__',
  '__weakref__', '_sock', 'accept', 'bind', 'close', 'connect',
  'connect_ex', 'dup', 'family', 'fileno', 'getpeername', 'getsockname',
  'getsockopt', 'gettimeout', 'listen', 'makefile', 'proto', 'recv',
  'recv_into', 'recvfrom', 'recvfrom_into', 'send', 'sendall', 'sendto',
  'setblocking', 'setsockopt', 'settimeout', 'shutdown', 'type']

[If asked, I would call that a "socket._socketobject object".]

Here's what a "socket object" returned from socket.fromfd() object looks like:

  repr(sock):
  <socket object, fd=6, family=2, type=1, protocol=0>
  
  dir(sock):
  ['__class__', '__delattr__', '__doc__', '__format__',
  '__getattribute__', '__hash__', '__init__', '__new__', '__reduce__',
  '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__',
  '__subclasshook__', 'accept', 'bind', 'close', 'connect',
  'connect_ex', 'dup', 'family', 'fileno', 'getpeername', 'getsockname',
  'getsockopt', 'gettimeout', 'listen', 'makefile', 'proto', 'recv',
  'recv_into', 'recvfrom', 'recvfrom_into', 'send', 'sendall', 'sendto',
  'setblocking', 'setsockopt', 'settimeout', 'shutdown', 'timeout',
  'type']

They're different types.

[That one I sould all a "socket object".]  

Note that the socket.socket() object has a '_sock' attribute, which
appears to contain an object like that returned by socket.fromfd():

  repr(osock._sock):
  <socket object, fd=4, family=2, type=1, protocol=0>

That prompts a question: given a "socket object" as returned by
socket.fromfd(), how does one create a "socket._socketobject object"
as returned by socket.socket()? 

It also makes one wonder why doesn't socket.fromfd() return the same
type of object as socke.socket()?  In what context would you want the
type of object returned from socket.fromrd() instead of that returned
by socket.socket()?

[An ssl context will wrap the latter, but not the former, in case
you're wondering why I care about the difference.]

Also, I passed socket.fromfd fd==5, and the resulting "socket object"
is using fd==6. Why does socket.fromfd() duplicate the fd?  If I
wanted the file descriptor duplicated, I would have do it myself!
[Yes, I know the documentation _says_ it will duplicate the fd, I just
don't understand why, and I think it a bad idea.]

-- 
Grant



From rosuav at gmail.com  Sat Jan 21 17:39:41 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 22 Jan 2017 09:39:41 +1100
Subject: How to create a socket.socket() object from a socket fd?
In-Reply-To: <o60naq$bbm$1@blaine.gmane.org>
References: <o60naq$bbm$1@blaine.gmane.org>
Message-ID: <CAPTjJmomx+pTiBGKfjpcHBZC2hwLtSHhTYN2ai-xhdU5s0wv3w@mail.gmail.com>

On Sun, Jan 22, 2017 at 9:28 AM, Grant Edwards
<grant.b.edwards at gmail.com> wrote:
> Given a Unix file discriptor for an open TCP socket, I can't figure
> out how to create a python 2.7 socket object like those returned by
> socket.socket()

I suspect you can't easily do it. In more recent Pythons, you can
socket.socket(fileno=N), but that doesn't exist in 2.7. But maybe.....

> Here's what a "socket object" returned by socket.socket() looks like:
>
>   repr(osock):
>   <socket._socketobject object at 0x7f701948f520>
>
> Here's what a "socket object" returned from socket.fromfd() object looks like:
>
>   repr(sock):
>   <socket object, fd=6, family=2, type=1, protocol=0>
>
> Note that the socket.socket() object has a '_sock' attribute, which
> appears to contain an object like that returned by socket.fromfd():
>
>   repr(osock._sock):
>   <socket object, fd=4, family=2, type=1, protocol=0>

... maybe you could construct a socket.socket(), then monkeypatch its _sock??

> [An ssl context will wrap the latter, but not the former, in case
> you're wondering why I care about the difference.]
>
> Also, I passed socket.fromfd fd==5, and the resulting "socket object"
> is using fd==6. Why does socket.fromfd() duplicate the fd?  If I
> wanted the file descriptor duplicated, I would have do it myself!
> [Yes, I know the documentation _says_ it will duplicate the fd, I just
> don't understand why, and I think it a bad idea.]

Agreed. It's much cleaner in Py3, but I don't know of a backport.

ChrisA


From grant.b.edwards at gmail.com  Sat Jan 21 17:41:31 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Sat, 21 Jan 2017 22:41:31 +0000 (UTC)
Subject: How to create a socket.socket() object from a socket fd?
References: <o60naq$bbm$1@blaine.gmane.org>
Message-ID: <o60o2r$6cd$1@blaine.gmane.org>

On 2017-01-21, Grant Edwards <grant.b.edwards at gmail.com> wrote:

> Given a Unix file discriptor for an open TCP socket, I can't figure
> out how to create a python 2.7 socket object like those returned by
> socket.socket()
>
> Based on the docs, one might think that socket.fromfd() would do that
> (since the docs say that's what it does):
[...]
> That prompts a question: given a "socket object" as returned by
> socket.fromfd(), how does one create a "socket._socketobject object"
> as returned by socket.socket()?

Of course I figured it out immediately after spending 15 minutes
whinging about it.

help(socket.socket) gives you a hint:

class _socketobject(__builtin__.object)
 |  socket([family[, type[, proto]]]) -> socket object
 |  
[...] 
 |  
 |  Methods defined here:
 |  
 |  __init__(self, family=2, type=1, proto=0, _sock=None)
 |  

Ah! There's a keyword argument that doesn't appear in the docs, so
let's try that...

  context = ssl.create_default_context()
  [...]  
  sock = socket.fromfd(fd2,socket.AF_INET,socket.SOCK_STREAM)
  nsock = socket.socket(socket.AF_INET,socket.SOCK_STREAM,_sock=sock)
  conn = context.wrap_socket(nsock, server_hostname="whatever.invalid")

That works.

-- 
Grant








From rosuav at gmail.com  Sat Jan 21 17:52:13 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 22 Jan 2017 09:52:13 +1100
Subject: How to create a socket.socket() object from a socket fd?
In-Reply-To: <o60o2r$6cd$1@blaine.gmane.org>
References: <o60naq$bbm$1@blaine.gmane.org> <o60o2r$6cd$1@blaine.gmane.org>
Message-ID: <CAPTjJmpwmbsjf5GPBWdV7g-063=E8LcsTwNdt0=priPAf6fNYQ@mail.gmail.com>

On Sun, Jan 22, 2017 at 9:41 AM, Grant Edwards
<grant.b.edwards at gmail.com> wrote:
>  |  __init__(self, family=2, type=1, proto=0, _sock=None)
>  |
>
> Ah! There's a keyword argument that doesn't appear in the docs, so
> let's try that...

That's marginally better than my monkeypatch-after-creation
suggestion, but still broadly the same. Your code may well break in
other Python implementations, but within CPython 2.7, you should be
pretty safe.

ChrisA


From christian at python.org  Sat Jan 21 18:28:48 2017
From: christian at python.org (Christian Heimes)
Date: Sun, 22 Jan 2017 00:28:48 +0100
Subject: How to create a socket.socket() object from a socket fd?
In-Reply-To: <o60o2r$6cd$1@blaine.gmane.org>
References: <o60naq$bbm$1@blaine.gmane.org> <o60o2r$6cd$1@blaine.gmane.org>
Message-ID: <c7e3116f-6e9c-5343-6f82-c491fb917800@python.org>

On 2017-01-21 23:41, Grant Edwards wrote:
> On 2017-01-21, Grant Edwards <grant.b.edwards at gmail.com> wrote:
> 
>> Given a Unix file discriptor for an open TCP socket, I can't figure
>> out how to create a python 2.7 socket object like those returned by
>> socket.socket()
>>
>> Based on the docs, one might think that socket.fromfd() would do that
>> (since the docs say that's what it does):
> [...]
>> That prompts a question: given a "socket object" as returned by
>> socket.fromfd(), how does one create a "socket._socketobject object"
>> as returned by socket.socket()?
> 
> Of course I figured it out immediately after spending 15 minutes
> whinging about it.
> 
> help(socket.socket) gives you a hint:
> 
> class _socketobject(__builtin__.object)
>  |  socket([family[, type[, proto]]]) -> socket object
>  |  
> [...] 
>  |  
>  |  Methods defined here:
>  |  
>  |  __init__(self, family=2, type=1, proto=0, _sock=None)
>  |  
> 
> Ah! There's a keyword argument that doesn't appear in the docs, so
> let's try that...
> 
>   context = ssl.create_default_context()
>   [...]  
>   sock = socket.fromfd(fd2,socket.AF_INET,socket.SOCK_STREAM)
>   nsock = socket.socket(socket.AF_INET,socket.SOCK_STREAM,_sock=sock)
>   conn = context.wrap_socket(nsock, server_hostname="whatever.invalid")
> 
> That works.

You might be interested in my small module
https://pypi.python.org/pypi/socketfromfd/ . I just releases a new
version with a fix for Python 2. Thanks for the hint! :)

The module correctly detects address family, socket type and proto from
a fd. It works correctly with e.g. IPv6 or Unix sockets. Ticket
https://bugs.python.org/issue28134 has additional background information
on the matter.

Christian



From __peter__ at web.de  Sat Jan 21 18:31:54 2017
From: __peter__ at web.de (Peter Otten)
Date: Sun, 22 Jan 2017 00:31:54 +0100
Subject: How to create a socket.socket() object from a socket fd?
References: <o60naq$bbm$1@blaine.gmane.org>
Message-ID: <o60r1b$k7k$1@blaine.gmane.org>

Grant Edwards wrote:

> Given a Unix file discriptor for an open TCP socket, I can't figure
> out how to create a python 2.7 socket object like those returned by
> socket.socket()
> 
> Based on the docs, one might think that socket.fromfd() would do that
> (since the docs say that's what it does):

[...]

> Note that the socket.socket() object has a '_sock' attribute, which
> appears to contain an object like that returned by socket.fromfd():
> 
>   repr(osock._sock):
>   <socket object, fd=4, family=2, type=1, protocol=0>
> 
> That prompts a question: given a "socket object" as returned by
> socket.fromfd(), how does one create a "socket._socketobject object"
> as returned by socket.socket()?

The socket.py source reveals that you can do it like this:

mysocket = socket.socket(_sock=socket.fromfd(...))

The code has

from _socket import socket  # actually a star import
...
_realsocket = socket
...
socket = _socketobject

which looks very much like an ad-hoc hack gone permanent.



From grant.b.edwards at gmail.com  Sat Jan 21 18:35:41 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Sat, 21 Jan 2017 23:35:41 +0000 (UTC)
Subject: How to create a socket.socket() object from a socket fd?
References: <o60naq$bbm$1@blaine.gmane.org> <o60o2r$6cd$1@blaine.gmane.org>
 <CAPTjJmpwmbsjf5GPBWdV7g-063=E8LcsTwNdt0=priPAf6fNYQ@mail.gmail.com>
Message-ID: <o60r8c$spr$1@blaine.gmane.org>

On 2017-01-21, Chris Angelico <rosuav at gmail.com> wrote:
> On Sun, Jan 22, 2017 at 9:41 AM, Grant Edwards
><grant.b.edwards at gmail.com> wrote:
>>  |  __init__(self, family=2, type=1, proto=0, _sock=None)
>>  |
>>
>> Ah! There's a keyword argument that doesn't appear in the docs, so
>> let's try that...
>
> That's marginally better than my monkeypatch-after-creation
> suggestion, but still broadly the same. Your code may well break in
> other Python implementations, but within CPython 2.7, you should be
> pretty safe.

For those of you still paying attention...

It looks like CPython 3.4 socket.fromfd() does return the same type
object as socket.socket().  And, using the fileno= argument to
socket.socket() avoids duplicating the descriptor.

Looks like somebody with a time machine read my original post...

-- 
Grant




From grant.b.edwards at gmail.com  Sat Jan 21 19:03:37 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Sun, 22 Jan 2017 00:03:37 +0000 (UTC)
Subject: How to create a socket.socket() object from a socket fd?
References: <o60naq$bbm$1@blaine.gmane.org> <o60o2r$6cd$1@blaine.gmane.org>
 <c7e3116f-6e9c-5343-6f82-c491fb917800@python.org>
Message-ID: <o60ssp$vf2$1@blaine.gmane.org>

On 2017-01-21, Christian Heimes <christian at python.org> wrote:

> You might be interested in my small module
> https://pypi.python.org/pypi/socketfromfd/ . I just releases a new
> version with a fix for Python 2. Thanks for the hint! :)
>
> The module correctly detects address family, socket type and proto from
> a fd. It works correctly with e.g. IPv6 or Unix sockets. Ticket
> https://bugs.python.org/issue28134 has additional background information
> on the matter.

Yes, thanks!

Just a few minutes ago I stumbled across that issue.  For Python3, I
was using:

  sock = socket.socket(fileno=fd)

But as you point out in that issue, the Python3 docs are wrong: when
using socket.socket(fileno=fd) you _do_ have to specify the correct
family and type parameters that correspond to the socket file
descriptor. So, I starting looking for os.getsockopt(), which doesn't
exist.

I see you use ctypes to call gestsockopt (that was going to be my next
step).

I suspect the code I'm working will end up being re-written in C for
the real product (so that it can run in-process in a thread rather
than as an external helper process).  If not, I'll have to use your
module (or something like it) so that the solution will work on both
IPv4 and IPv6 TCP sockets (I'd also like it to work with Unix domain
sockets, but the piece at the other end of the socket connection
currently only supports TCP).

-- 
Grant






From grant.b.edwards at gmail.com  Sat Jan 21 19:52:46 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Sun, 22 Jan 2017 00:52:46 +0000 (UTC)
Subject: How to create a socket.socket() object from a socket fd?
References: <o60naq$bbm$1@blaine.gmane.org>
Message-ID: <o60vou$714$1@blaine.gmane.org>

Newsgroups: gmane.comp.python.general
From: Grant Edwards <grant.b.edwards at gmail.com>
Subject: Re: How to create a socket.socket() object from a socket fd?
References: <o60naq$bbm$1 at blaine.gmane.org> <o60o2r$6cd$1 at blaine.gmane.org> <c7e3116f-6e9c-5343-6f82-c491fb917800 at python.org>
Followup-To: 

<rant>

I'm still baffled why the standard library fromfd() code dup()s the
descriptor.

According to the comment in the CPython sources, the author of
fromfd() is guessing that the user wants to be able to close the
descriptor separately from the socket.

If the user wanted the socket object to use a duplicate descriptor for
some reason, the caller should call os.dup() -- it's only _eight_
keystrokes.  Eight keystrokes that makes it obvious to anybody reading
the code that there are now two descriptors and you have to close both
the original descriptor and the socket.

When you create a Python file object from a file descriptor using
os.fdopen(), does it dup the descriptor?  No.  Would a reasonable
person expect socket.fromfd() to duplicate the descriptor?  No.

Should it?

No.

I know... that particular mistake is set in stone now, and it's not
going to change.  But I feel better.  :)


     $ python
     Python 2.7.12 (default, Dec  6 2016, 23:41:51) 
     [GCC 4.9.3] on linux2
     Type "help", "copyright", "credits" or "license" for more information.
     >>> import this
     The Zen of Python, by Tim Peters
     
     Beautiful is better than ugly.
**** Explicit is better than implicit.
     Simple is better than complex.
     Complex is better than complicated.
     Flat is better than nested.
     Sparse is better than dense.
**** Readability counts.
     Special cases aren't special enough to break the rules.
     Although practicality beats purity.
     Errors should never pass silently.
     Unless explicitly silenced.
**** In the face of ambiguity, refuse the temptation to guess.
     There should be one-- and preferably only one --obvious way to do it.
     Although that way may not be obvious at first unless you're Dutch.
     Now is better than never.
     Although never is often better than *right* now.
     If the implementation is hard to explain, it's a bad idea.
     If the implementation is easy to explain, it may be a good idea.
     Namespaces are one honking great idea -- let's do more of those!

</rant>



From steve+python at pearwood.info  Sat Jan 21 21:36:47 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Sun, 22 Jan 2017 13:36:47 +1100
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <58836875$0$1600$c3e8da3$5496439d@news.astraweb.com>
 <m1wpdo2yzz.fsf@iKarel.lan> <87o9z0fawl.fsf@elektro.pacujo.net>
Message-ID: <58841ac0$0$1609$c3e8da3$5496439d@news.astraweb.com>

On Sun, 22 Jan 2017 06:52 am, Marko Rauhamaa wrote:

> Pete Forman <petef4+usenet at gmail.com>:
> 
>> Surrogates only exist in UTF-16. They are expressly forbidden in UTF-8
>> and UTF-32.
> 
> Also, they don't exist as Unicode code points. Python shouldn't allow
> surrogate characters in strings.

Not quite. This is where it gets a bit messy and confusing. The bottom line
is: surrogates *are* code points, but they aren't *characters*. Strings
which contain surrogates are strictly speaking illegal, although some
programming languages (including Python) allow them.

The Unicode standard defines surrogates as follows:

http://www.unicode.org/glossary/

- Surrogate Character. A misnomer. It would be an encoded character 
  having a surrogate code point, which is impossible. Do not use 
  this term.

- Surrogate Code Point. A Unicode code point in the range 
  U+D800..U+DFFF. Reserved for use by UTF-16, where a pair of 
  surrogate code units (a high surrogate followed by a low surrogate)
  ?stand in? for a supplementary code point.

- Surrogate Pair. A representation for a single abstract character
  that consists of a sequence of two 16-bit code units, where the
  first value of the pair is a high-surrogate code unit, and the
  second is a low-surrogate code unit. (See definition D75 in 
  Section 3.8, Surrogates.)


http://www.unicode.org/versions/Unicode9.0.0/ch03.pdf#G2630


So far so good, this is clear: surrogates are not characters. Surrogate
pairs are only used by UTF-16 (since that's the only UTF which uses 16-bit
code units).

Suppose you read two code units (four bytes) in UTF-16 (big endian):

b'\xd8\x02\xdd\x00'

That could be ambiguous, as it could mean:

- a single code point, U+10900 PHOENICIAN LETTER ALF, encoded as
  the surrogate pair, U+D802 U+DD00;

- two surrogate code points, U+D802 followed by U+DD00.

UTF-16 definitely rejects the second alternative and categorically makes
only the first valid. To ensure that is the only valid interpretation, the
second is explicitly disallowed: conforming Unicode strings are not allowed
to include surrogate code points, regardless of whether you are intending
to encode them in UTF-32 (where there is no ambiguity) or UTF-16 (where
there is). Only UTF-16 encoded bytes are allowed to include surrogate code
*units*, and only in pairs.

However, Python (and other languages?) take a less strict approach. In
Python 3.3 and better, the code point U+10900 (Phoenician Alf) is encoded
using a single four-byte code unit: 0x00010900', so there's no ambiguity.
That allows Python to encode surrogates as double-byte code units with no
ambiguity: the interpreter can distinguish a single 32 byte number
0x00010900 from a pair of 16 bit numbers 0x0001 0x0900 and treat the first
as Alf and the second as two surrogates.

By the letter of the Unicode standard, it should not do this, but
nevertheless it does and it appears to do no real harm and have some
benefit.


The glossary also says:


- High-Surrogate Code Point. A Unicode code point in the range 
  U+D800 to U+DBFF. (See definition D71 in Section 3.8, Surrogates.)

- High-Surrogate Code Unit. A 16-bit code unit in the range D800_16 
  to DBFF_16, used in UTF-16 as the leading code unit of a surrogate
  pair. Also known as a leading surrogate. (See definition D72 in 
  Section 3.8, Surrogates.)

- Low-Surrogate Code Point. A Unicode code point in the range 
  U+DC00 to U+DFFF. (See definition D73 in Section 3.8, Surrogates.)

- Low-Surrogate Code Unit. A 16-bit code unit in the range DC00_16
  to DFFF_16, used in UTF-16 as the trailing code unit of a surrogate
  pair. Also known as a trailing surrogate. (See definition D74 in
  Section 3.8, Surrogates.)


So we can certainly talk about surrogates being code points: the code points
U+D800 through U+DFFF inclusive are surrogate code points, but not
characters.

They're not "non-characters" either. Unicode includes exactly 66 code points
formally defined as "non-characters":

- Noncharacter. A code point that is permanently reserved for internal
  use. Noncharacters consist of the values U+nFFFE and U+nFFFF (where
  n is from 0 to 1016), and the values U+FDD0..U+FDEF. See the FAQ on
  Private-Use Characters, Noncharacters and Sentinels.

http://www.unicode.org/faq/private_use.html#noncharacters

So even though noncharacters (with or without the hyphen) are code points
reserved for internal use, and surrogates are code points reserved for the
internal use of the UTF-16 encoder, and surrogates are not characters,
surrogates are not noncharacters.

Naming things is hard.


>    Thus the range of code points that are available for use as
>    characters is U+0000?U+D7FF and U+E000?U+10FFFF (1,112,064 code
>    points).
> 
>    <URL: https://en.wikipedia.org/wiki/Unicode>

That is correct for a strictly conforming Unicode implementation.


>> py> low = '\uDC37'
> 
> That should raise a SyntaxError exception.

If Python was strictly conforming, that is correct, but it turns out there
are some useful things you can do with strings if you allow surrogates.




-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From steve+python at pearwood.info  Sat Jan 21 21:42:57 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Sun, 22 Jan 2017 13:42:57 +1100
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <58836875$0$1600$c3e8da3$5496439d@news.astraweb.com>
 <m1wpdo2yzz.fsf@iKarel.lan> <87o9z0fawl.fsf@elektro.pacujo.net>
 <m1shoc2mgu.fsf@iKarel.lan>
Message-ID: <58841c32$0$1612$c3e8da3$5496439d@news.astraweb.com>

On Sun, 22 Jan 2017 07:21 am, Pete Forman wrote:

> Marko Rauhamaa <marko at pacujo.net> writes:
> 
>>> py> low = '\uDC37'
>>
>> That should raise a SyntaxError exception.
> 
> Quite. My point was that with older Python on a narrow build (Windows
> and Mac) you need to understand that you are using UTF-16 rather than
> Unicode.

But you're *not* using UTF-16, at least not proper UTF-16, in older narrow
builds. If you were, then Unicode strings u'...' containing surrogate pairs
would be treated as supplementary single code points, but they aren't.

unichr() doesn't support supplementary code points in narrow builds:

[steve at ando ~]$ python2.7 -c "print len(unichr(0x10900))"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ValueError: unichr() arg not in range(0x10000) (narrow Python build)


and even if you sneak a supplementary code point in, it is treated wrongly:

[steve at ando ~]$ python2.7 -c "print len(u'\U00010900')"
2


So Python narrow builds are more like a bastard hybrid of UCS-2 and UTF-16.




-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From steve+comp.lang.python at pearwood.info  Sun Jan 22 01:47:35 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 22 Jan 2017 17:47:35 +1100
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <CALvWhxs0xcC1iJjgHx5y_RynneiKtdMqFLn9R2wsDgsvND1gMw@mail.gmail.com>
 <mailman.33.1484953608.9761.python-list@python.org>
 <m160l945lz.fsf@iKarel.lan>
 <CAPTjJmqxiATbYAHBA29wiPco1NgCDAUjproeS03yhgtMJNoumw@mail.gmail.com>
 <20170121064546.0eba2e4c@bigbox.christie.dr>
 <mailman.2.1485003269.2473.python-list@python.org>
 <588373cf$0$1602$c3e8da3$5496439d@news.astraweb.com>
 <20170121135846.7b54297b@bigbox.christie.dr>
 <mailman.15.1485048866.2473.python-list@python.org>
Message-ID: <58845588$0$2736$c3e8da3$76491128@news.astraweb.com>

On Sunday 22 January 2017 06:58, Tim Chase wrote:

> Right.  It gets even weirder (edge-case'ier) when dealing with
> combining characters:
> 
> 
>>>> s = "man\N{COMBINING TILDE}ana"
>>>> for i, c in enumerate(s): print("%i: %s" % (i, c))
> ...
> 0: m
> 1: a
> 2: n
> 3:?
> 4: a
> 5: n
> 6: a
>>>> ''.join(reversed(s))
> 'an?nam'
> 
> Offsetting s[3:] produces a (sub)string that begins with a combining
> character that doesn't have anything preceding it to combine with.

That doesn't matter. Unicode is a universal character set, not a universal 
*grapheme* set. But even speaking about characters is misleading: Unicode's 
"characters" (note the scare quotes) are abstract code points which can 
represent at least:

- letters of alphabets
- digits
- punctuation marks
- ideographs
- line drawing symbols
- emoji
- noncharacters

Since it doesn't promise to only provide graphemes (I can write "$\N{COMBINING 
TILDE}" which is not a valid grapheme in any human language) it doesn't matter 
if you end up with lone combining characters. Or rather, it does matter, but 
fixing that is not Unicode's responsibility. That should become a layer built 
on top of Unicode.


>> It's like seek() and tell() on text files: you cannot seek to
>> arbitrary positions, but only to the opaque positions returned by
>> tell. That's unacceptable for strings.
> 
> I'm still unclear on *why* this would be considered unacceptable for
> strings.

Sometimes you want to slice at a particular index which is *not* an opaque 
position returned by find().

text[offset + 1:]

Of for that matter:

middle_character = text[len(text)//2]


Forbidding those sorts of operations are simply too big a break with previous 
versions.


> It makes sense when dealing with byte-strings, since they
> contain binary data that may need to get sliced at arbitrary
> offsets.  But for strings, slicing only makes sense (for every
> use-case I've been able to come up with) in the context of known
> offsets like you describe with tell().

I'm sorry, I find it hard to believe that you've never needed to add or 
subtract 1 from a given offset returned by find() or equivalent.


> The cost of not using opaque
> tell()like offsets is, as you describe, slicing in the middle of
> characters.

>> You could avoid that error by increasing the offset by the right
>> amount:
>> 
>> stuff = text[offset + len("?".encode('utf-8'):]
>> 
>> which is awful. I believe that's what Go and Julia expect you to do.
> 
> It may be awful, but only because it hasn't been pythonified.

No, it's awful no matter what. It makes it painful to reason about which code 
points will be picked up by a slice. What's the length of...?

text[offset:offset+5]

In current Python, that's got to be five code points (excluding the edge cases 
of slicing past the end of the string). But with opaque indexes, that could be 
anything from 1 to 5 code points.


> If the
> result from calling .find() on a string returns a "StringOffset"
> object, then it would make sense that its __add__/__radd__ methods
> would accept an integer and to such translation for you.

At cost of predictability.


>> You can avoid this by having the interpreter treat the Python-level
>> indexes as opaque "code point offsets", and converting them to and
>> from "byte offsets" as needed. That's not even very hard. But it
>> either turns every indexing into O(N) (since you have to walk the
>> string to count which byte represents the nth code point)
> 
> The O(N) cost has to be paid at some point, but I'd put forth that
> other operations like .find() already pay that O(N) cost and can
> return an opaque "offset token" that can be subsequently used for O(1)
> indexing (multiple times if needed).

Sure -- but only at the cost of blowing out the complexity and memory 
requirements of the string, which completely negates the point in using UTF-8 
in the first place.



-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From marko at pacujo.net  Sun Jan 22 03:13:10 2017
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sun, 22 Jan 2017 10:13:10 +0200
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <58836875$0$1600$c3e8da3$5496439d@news.astraweb.com>
 <m1wpdo2yzz.fsf@iKarel.lan> <87o9z0fawl.fsf@elektro.pacujo.net>
 <m1shoc2mgu.fsf@iKarel.lan>
 <CACL+1auxeV=Onh1WYZrvbTubiu=w_B_EftfLW+1HRezo0Jjo1A@mail.gmail.com>
 <mailman.4.1485031815.2473.python-list@python.org>
Message-ID: <87fukbtsvd.fsf@elektro.pacujo.net>

eryk sun <eryksun at gmail.com>:

> On Sat, Jan 21, 2017 at 8:21 PM, Pete Forman <petef4+usenet at gmail.com> wrote:
>> Marko Rauhamaa <marko at pacujo.net> writes:
>>
>>>> py> low = '\uDC37'
>>>
>>> That should raise a SyntaxError exception.
>>
>> Quite. [...]
>
> CPython allows surrogate codes for use with the "surrogateescape" and
> "surrogatepass" error handlers, which are used for POSIX and Windows
> file-system encoding, respectively.

Yes, but at the cost of violating Unicode, leading to unprintable
strings etc. In my opinion, Python should have "stayed pure" instead of
playing cheap tricks with surrogates.

(Of course, Unicode itself is a mess, but that's another story.)


Marko


From marko at pacujo.net  Sun Jan 22 03:34:07 2017
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sun, 22 Jan 2017 10:34:07 +0200
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <58836875$0$1600$c3e8da3$5496439d@news.astraweb.com>
 <m1wpdo2yzz.fsf@iKarel.lan> <87o9z0fawl.fsf@elektro.pacujo.net>
 <58841ac0$0$1609$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <87bmuztrwg.fsf@elektro.pacujo.net>

Steve D'Aprano <steve+python at pearwood.info>:

> On Sun, 22 Jan 2017 06:52 am, Marko Rauhamaa wrote:
>> Also, [surrogates] don't exist as Unicode code points. Python
>> shouldn't allow surrogate characters in strings.
>
> Not quite. This is where it gets a bit messy and confusing. The bottom
> line is: surrogates *are* code points, but they aren't *characters*.

All animals are equal, but some animals are more equal than others.

> Strings which contain surrogates are strictly speaking illegal,
> although some programming languages (including Python) allow them.

Python shouldn't allow them.

> The Unicode standard defines surrogates as follows:
> [...]
>
> - Surrogate Code Point. A Unicode code point in the range 
>   U+D800..U+DFFF. Reserved for use by UTF-16,

The writer of the standard is playing word games, maybe to offer a fig
leaf to Windows, Java et al.

> By the letter of the Unicode standard, [Python] should not do this,
> but nevertheless it does and it appears to do no real harm and have
> some benefit.

I'm afraid Python's choice may lead to exploitable security holes in
Python programs.

>>> py> low = '\uDC37'
>> 
>> That should raise a SyntaxError exception.
>
> If Python was strictly conforming, that is correct, but it turns out
> there are some useful things you can do with strings if you allow
> surrogates.

Conceptual confusion is a high price to pay for such tricks.


Marko


From christian at python.org  Sun Jan 22 06:48:31 2017
From: christian at python.org (Christian Heimes)
Date: Sun, 22 Jan 2017 12:48:31 +0100
Subject: How to create a socket.socket() object from a socket fd?
In-Reply-To: <o60ssp$vf2$1@blaine.gmane.org>
References: <o60naq$bbm$1@blaine.gmane.org> <o60o2r$6cd$1@blaine.gmane.org>
 <c7e3116f-6e9c-5343-6f82-c491fb917800@python.org>
 <o60ssp$vf2$1@blaine.gmane.org>
Message-ID: <eb1a8266-f8aa-e630-78eb-df49a647116a@python.org>

On 2017-01-22 01:03, Grant Edwards wrote:
> On 2017-01-21, Christian Heimes <christian at python.org> wrote:
> 
>> You might be interested in my small module
>> https://pypi.python.org/pypi/socketfromfd/ . I just releases a new
>> version with a fix for Python 2. Thanks for the hint! :)
>>
>> The module correctly detects address family, socket type and proto from
>> a fd. It works correctly with e.g. IPv6 or Unix sockets. Ticket
>> https://bugs.python.org/issue28134 has additional background information
>> on the matter.
> 
> Yes, thanks!
> 
> Just a few minutes ago I stumbled across that issue.  For Python3, I
> was using:
> 
>   sock = socket.socket(fileno=fd)
> 
> But as you point out in that issue, the Python3 docs are wrong: when
> using socket.socket(fileno=fd) you _do_ have to specify the correct
> family and type parameters that correspond to the socket file
> descriptor. So, I starting looking for os.getsockopt(), which doesn't
> exist.
> 
> I see you use ctypes to call gestsockopt (that was going to be my next
> step).
> 
> I suspect the code I'm working will end up being re-written in C for
> the real product (so that it can run in-process in a thread rather
> than as an external helper process).  If not, I'll have to use your
> module (or something like it) so that the solution will work on both
> IPv4 and IPv6 TCP sockets (I'd also like it to work with Unix domain
> sockets, but the piece at the other end of the socket connection
> currently only supports TCP).

I wanted to fix the function before 3.6.0 came out but I faced some
resistance. My approach was deemed too magic and not fully functional on
some platforms. Other core devs are underestimating the severity of the
issue. Even in simple examples with IPv4 and IPv6 it breaks
getpeername(). I'd appreciate if you could jump in a leave a comment on
the ticket to show your support. :)

By the way I just pushed another commit with a new feature just for you.
But see for yourself:

https://github.com/tiran/socketfromfd/commit/0a2fd6dae86267cedea5ae8b956e2876e6057c74

Christian


From steve+python at pearwood.info  Sun Jan 22 09:01:32 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Mon, 23 Jan 2017 01:01:32 +1100
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <58836875$0$1600$c3e8da3$5496439d@news.astraweb.com>
 <m1wpdo2yzz.fsf@iKarel.lan> <87o9z0fawl.fsf@elektro.pacujo.net>
 <58841ac0$0$1609$c3e8da3$5496439d@news.astraweb.com>
 <87bmuztrwg.fsf@elektro.pacujo.net>
Message-ID: <5884bb3d$0$1619$c3e8da3$5496439d@news.astraweb.com>

On Sun, 22 Jan 2017 07:34 pm, Marko Rauhamaa wrote:

> Steve D'Aprano <steve+python at pearwood.info>:
> 
>> On Sun, 22 Jan 2017 06:52 am, Marko Rauhamaa wrote:
>>> Also, [surrogates] don't exist as Unicode code points. Python
>>> shouldn't allow surrogate characters in strings.
>>
>> Not quite. This is where it gets a bit messy and confusing. The bottom
>> line is: surrogates *are* code points, but they aren't *characters*.
> 
> All animals are equal, but some animals are more equal than others.

Huh?


>> Strings which contain surrogates are strictly speaking illegal,
>> although some programming languages (including Python) allow them.
> 
> Python shouldn't allow them.

That's one opinion.


>> The Unicode standard defines surrogates as follows:
>> [...]
>>
>> - Surrogate Code Point. A Unicode code point in the range
>>   U+D800..U+DFFF. Reserved for use by UTF-16,
> 
> The writer of the standard is playing word games, maybe to offer a fig
> leaf to Windows, Java et al.

Seriously?


>> By the letter of the Unicode standard, [Python] should not do this,
>> but nevertheless it does and it appears to do no real harm and have
>> some benefit.
> 
> I'm afraid Python's choice may lead to exploitable security holes in
> Python programs.

Feel free to back up that with an actual demonstration of an exploit, rather
than just FUD.


>>>> py> low = '\uDC37'
>>> 
>>> That should raise a SyntaxError exception.
>>
>> If Python was strictly conforming, that is correct, but it turns out
>> there are some useful things you can do with strings if you allow
>> surrogates.
> 
> Conceptual confusion is a high price to pay for such tricks.

There's a lot to comprehend about Unicode. I don't see that Python's
non-strict implementation is harder to understand than the strict version.



-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From marko at pacujo.net  Sun Jan 22 10:19:34 2017
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sun, 22 Jan 2017 17:19:34 +0200
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <58836875$0$1600$c3e8da3$5496439d@news.astraweb.com>
 <m1wpdo2yzz.fsf@iKarel.lan> <87o9z0fawl.fsf@elektro.pacujo.net>
 <58841ac0$0$1609$c3e8da3$5496439d@news.astraweb.com>
 <87bmuztrwg.fsf@elektro.pacujo.net>
 <5884bb3d$0$1619$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <87ziijqfzt.fsf@elektro.pacujo.net>

Steve D'Aprano <steve+python at pearwood.info>:

> On Sun, 22 Jan 2017 07:34 pm, Marko Rauhamaa wrote:
>
>> Steve D'Aprano <steve+python at pearwood.info>:
>> 
>>> On Sun, 22 Jan 2017 06:52 am, Marko Rauhamaa wrote:
>>>> Also, [surrogates] don't exist as Unicode code points. Python
>>>> shouldn't allow surrogate characters in strings.
>>>
>>> Not quite. This is where it gets a bit messy and confusing. The
>>> bottom line is: surrogates *are* code points, but they aren't
>>> *characters*.
>> 
>> All animals are equal, but some animals are more equal than others.
>
> Huh?

There is no difference between 0xD800 and 0xD8000000. They are both
numbers that don't--and won't--represent anything in Unicode. It's
pointless to call one a "code point" and not the other one. A code point
that isn't code for anything can barely be called a code point.

I'm guessing 0xD800 is called a code point because it was always called
that. It was dropped out when UTF-16 was invented but they didn't want
to "demote" the number retroactively, especially since Windows and Java
already were allowing them in strings.

>>> By the letter of the Unicode standard, [Python] should not do this,
>>> but nevertheless it does and it appears to do no real harm and have
>>> some benefit.
>> 
>> I'm afraid Python's choice may lead to exploitable security holes in
>> Python programs.
>
> Feel free to back up that with an actual demonstration of an exploit,
> rather than just FUD.

It might come as a surprise to programmers that pathnames cannot be
UTF-encoded or displayed. Also, those situations might not show up
during testing but only with appropriately crafted input.


Marko


From grant.b.edwards at gmail.com  Sun Jan 22 15:18:49 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Sun, 22 Jan 2017 20:18:49 +0000 (UTC)
Subject: Is Python SSL API thread-safe?
Message-ID: <o63439$r2a$1@blaine.gmane.org>

Is the Python SSL API thread-safe with respect to recv() and send()?

IOW, can I have one thread doing blocking recv() calls on an SSL
connection object while "simultaneously" a second thread is calling
send() on that same connection object?

I assumed that was allowed, but I can't find anything in the
documentation that actually says it is.

-- 
Grant





From jon+usenet at unequivocal.eu  Sun Jan 22 15:55:16 2017
From: jon+usenet at unequivocal.eu (Jon Ribbens)
Date: Sun, 22 Jan 2017 20:55:16 -0000 (UTC)
Subject: Is Python SSL API thread-safe?
References: <o63439$r2a$1@blaine.gmane.org>
 <mailman.18.1485116366.2473.python-list@python.org>
Message-ID: <slrno8a74o.2ca.jon+usenet@sable.unequivocal.eu>

On 2017-01-22, Grant Edwards <grant.b.edwards at gmail.com> wrote:
> Is the Python SSL API thread-safe with respect to recv() and send()?
>
> IOW, can I have one thread doing blocking recv() calls on an SSL
> connection object while "simultaneously" a second thread is calling
> send() on that same connection object?

I think this question is equivalent to asking "is OpenSSL thread-safe",
the answer to which would appear to be "yes":
https://www.openssl.org/docs/man1.0.2/crypto/threads.html
(the necessary functions mentioned on that page, threadid_func and
locking_function are indeed set by Python).


From christian at python.org  Sun Jan 22 16:34:38 2017
From: christian at python.org (Christian Heimes)
Date: Sun, 22 Jan 2017 22:34:38 +0100
Subject: Is Python SSL API thread-safe?
In-Reply-To: <o63439$r2a$1@blaine.gmane.org>
References: <o63439$r2a$1@blaine.gmane.org>
Message-ID: <4f923fe7-fa75-698e-37b9-3e4423c7e59b@python.org>

On 2017-01-22 21:18, Grant Edwards wrote:
> Is the Python SSL API thread-safe with respect to recv() and send()?
> 
> IOW, can I have one thread doing blocking recv() calls on an SSL
> connection object while "simultaneously" a second thread is calling
> send() on that same connection object?
> 
> I assumed that was allowed, but I can't find anything in the
> documentation that actually says it is.

OpenSSL and Python's ssl module are thread-safe. However IO is not safe
concerning reentrancy. You cannot safely share a SSLSocket between
threads without a mutex. Certain aspects of the TLS protocol can cause
interesting side effects. A recv() call can send data across a wire and
a send() call can receive data from the wire, e.g. during re-keying.

In order to archive reentrancy, you have to do all IO yourself by
operating the SSL connection in non-blocking mode or with a Memorio-BIO
https://docs.python.org/3/library/ssl.html#ssl-nonblocking



From jf_byrnes at comcast.net  Sun Jan 22 19:10:18 2017
From: jf_byrnes at comcast.net (Jim)
Date: Sun, 22 Jan 2017 18:10:18 -0600
Subject: pyuno in Libreoffice 5.1.4.2
Message-ID: <o63hl4$la5$1@blaine.gmane.org>

Does anyone know if the changes outlined here [1] have been implemented?

Supposedly changes have been made to pyuno to make it more pythonic.

Item 2 Cellranges says that:
cell = sheet.getCellByPosition(cellCol + col, cellRow + row)
Can be written as:
cell = sheet.cellrange[cellRow + row, cellCol + col]

But when I try that I get:

Traceback (most recent call last):
   File 
"/home/jfb/.config/libreoffice/4/user/Scripts/python/enter_INV/enter_INV.py", 
line 68, in keyPressed
     move_selected_cell(1, 0)
   File 
"/home/jfb/.config/libreoffice/4/user/Scripts/python/enter_INV/enter_INV.py", 
line 112, in move_selected_cell
     cell = sheet.cellrange[cellRow + row, cellCol + col]
AttributeError: cellrange

Or maybe I am misunderstanding how to use it.

Regards,  Jim

[1] 
https://cgit.freedesktop.org/libreoffice/core/commit/?id=af8143bc40cf2cfbc12e77c9bb7de01b655f7b30 




From grant.b.edwards at gmail.com  Sun Jan 22 20:01:59 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Mon, 23 Jan 2017 01:01:59 +0000 (UTC)
Subject: Is Python SSL API thread-safe?
References: <o63439$r2a$1@blaine.gmane.org>
 <4f923fe7-fa75-698e-37b9-3e4423c7e59b@python.org>
Message-ID: <o63km7$v0$1@blaine.gmane.org>

On 2017-01-22, Christian Heimes <christian at python.org> wrote:
> On 2017-01-22 21:18, Grant Edwards wrote:
>> Is the Python SSL API thread-safe with respect to recv() and send()?
>> 
>> IOW, can I have one thread doing blocking recv() calls on an SSL
>> connection object while "simultaneously" a second thread is calling
>> send() on that same connection object?
>> 
>> I assumed that was allowed, but I can't find anything in the
>> documentation that actually says it is.
>
> OpenSSL and Python's ssl module are thread-safe. However IO is not safe
> concerning reentrancy. You cannot safely share a SSLSocket between
> threads without a mutex. Certain aspects of the TLS protocol can cause
> interesting side effects. A recv() call can send data across a wire and
> a send() call can receive data from the wire, e.g. during re-keying.
>
> In order to archive reentrancy, you have to do all IO yourself by
> operating the SSL connection in non-blocking mode or with a Memorio-BIO
> https://docs.python.org/3/library/ssl.html#ssl-nonblocking

IOW, what I'm doing is not safe.  Rats.

-- 
Grant





From python at mrabarnett.plus.com  Sun Jan 22 20:02:03 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Mon, 23 Jan 2017 01:02:03 +0000
Subject: pyuno in Libreoffice 5.1.4.2
In-Reply-To: <o63hl4$la5$1@blaine.gmane.org>
References: <o63hl4$la5$1@blaine.gmane.org>
Message-ID: <f4be81f8-0824-86b1-f791-50729a5d08b8@mrabarnett.plus.com>

On 2017-01-23 00:10, Jim wrote:
> Does anyone know if the changes outlined here [1] have been implemented?
>
> Supposedly changes have been made to pyuno to make it more pythonic.
>
> Item 2 Cellranges says that:
> cell = sheet.getCellByPosition(cellCol + col, cellRow + row)
> Can be written as:
> cell = sheet.cellrange[cellRow + row, cellCol + col]
>
> But when I try that I get:
>
> Traceback (most recent call last):
>    File
> "/home/jfb/.config/libreoffice/4/user/Scripts/python/enter_INV/enter_INV.py",
> line 68, in keyPressed
>      move_selected_cell(1, 0)
>    File
> "/home/jfb/.config/libreoffice/4/user/Scripts/python/enter_INV/enter_INV.py",
> line 112, in move_selected_cell
>      cell = sheet.cellrange[cellRow + row, cellCol + col]
> AttributeError: cellrange
>
> Or maybe I am misunderstanding how to use it.
>
I think it might be direct indexing of the sheet:

     cell = sheet[cellRow + row, cellCol + col]

> Regards,  Jim
>
> [1]
> https://cgit.freedesktop.org/libreoffice/core/commit/?id=af8143bc40cf2cfbc12e77c9bb7de01b655f7b30
>
>



From jf_byrnes at comcast.net  Sun Jan 22 20:30:08 2017
From: jf_byrnes at comcast.net (Jim)
Date: Sun, 22 Jan 2017 19:30:08 -0600
Subject: pyuno in Libreoffice 5.1.4.2
In-Reply-To: <f4be81f8-0824-86b1-f791-50729a5d08b8@mrabarnett.plus.com>
References: <o63hl4$la5$1@blaine.gmane.org>
 <f4be81f8-0824-86b1-f791-50729a5d08b8@mrabarnett.plus.com>
Message-ID: <o63mar$d7o$1@blaine.gmane.org>

On 01/22/2017 07:02 PM, MRAB wrote:
> On 2017-01-23 00:10, Jim wrote:
>> Does anyone know if the changes outlined here [1] have been implemented?
>>
>> Supposedly changes have been made to pyuno to make it more pythonic.
>>
>> Item 2 Cellranges says that:
>> cell = sheet.getCellByPosition(cellCol + col, cellRow + row)
>> Can be written as:
>> cell = sheet.cellrange[cellRow + row, cellCol + col]
>>
>> But when I try that I get:
>>
>> Traceback (most recent call last):
>>    File
>> "/home/jfb/.config/libreoffice/4/user/Scripts/python/enter_INV/enter_INV.py",
>>
>> line 68, in keyPressed
>>      move_selected_cell(1, 0)
>>    File
>> "/home/jfb/.config/libreoffice/4/user/Scripts/python/enter_INV/enter_INV.py",
>>
>> line 112, in move_selected_cell
>>      cell = sheet.cellrange[cellRow + row, cellCol + col]
>> AttributeError: cellrange
>>
>> Or maybe I am misunderstanding how to use it.
>>
> I think it might be direct indexing of the sheet:
>
>     cell = sheet[cellRow + row, cellCol + col]
>
>> Regards,  Jim
>>
>> [1]
>> https://cgit.freedesktop.org/libreoffice/core/commit/?id=af8143bc40cf2cfbc12e77c9bb7de01b655f7b30
>>

You are correct, that worked. Thank you very much.

Regards,  Jim




From steve+python at pearwood.info  Sun Jan 22 21:14:20 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Mon, 23 Jan 2017 13:14:20 +1100
Subject: PEP 393 vs UTF-8 Everywhere
References: <m1d1fh4ay1.fsf@iKarel.lan>
 <58836875$0$1600$c3e8da3$5496439d@news.astraweb.com>
 <m1wpdo2yzz.fsf@iKarel.lan> <87o9z0fawl.fsf@elektro.pacujo.net>
 <58841ac0$0$1609$c3e8da3$5496439d@news.astraweb.com>
 <87bmuztrwg.fsf@elektro.pacujo.net>
 <5884bb3d$0$1619$c3e8da3$5496439d@news.astraweb.com>
 <87ziijqfzt.fsf@elektro.pacujo.net>
Message-ID: <588566fd$0$1619$c3e8da3$5496439d@news.astraweb.com>

On Mon, 23 Jan 2017 02:19 am, Marko Rauhamaa wrote:

> Steve D'Aprano <steve+python at pearwood.info>:
> 
>> On Sun, 22 Jan 2017 07:34 pm, Marko Rauhamaa wrote:
>>
>>> Steve D'Aprano <steve+python at pearwood.info>:
>>> 
>>>> On Sun, 22 Jan 2017 06:52 am, Marko Rauhamaa wrote:
>>>>> Also, [surrogates] don't exist as Unicode code points. Python
>>>>> shouldn't allow surrogate characters in strings.
>>>>
>>>> Not quite. This is where it gets a bit messy and confusing. The
>>>> bottom line is: surrogates *are* code points, but they aren't
>>>> *characters*.
>>> 
>>> All animals are equal, but some animals are more equal than others.
>>
>> Huh?
> 
> There is no difference between 0xD800 and 0xD8000000. 

Arithmetic disagrees:

py> 0xD800 == 0xD8000000
False


> They are both 
> numbers that don't--and won't--represent anything in Unicode.

Your use of hex notation 0x... indicates that you're talking about code
units rather than U+... code points. The first one 0xD800 could be:

- a Little Endian double-byte code unit for '?' in either UCS-2 or UTF-16;

- a Big Endian double-byte code unit that has no special meaning in UCS-2;

- one half of a surrogate pair (two double-byte code units) in Big Endian
  UTF-16, encoding some unknown supplementary code point.

The second one 0xD8000000 could be:

- a C long (four-byte int) 3623878656, which is out of range for Big Endian
  UCS-4 or UTF-32;

- the Little Endian four-byte code unit for '?' in either UCS-4 or UTF-32.


> It's pointless to call one a "code point" and not the other one. 

Neither of them are code points. You're confusing the concrete
representation with the abstract character.

Perhaps you meant to compare the code point U+D800 to, well, there's no
comparison to be made, because "U+D8000000" is not valid and is completely
out of range. The largest code point is U+10FFFF.


> A code point 
> that isn't code for anything can barely be called a code point.

It does have a purpose. Or even more than one.

- It ensures that there is a one-to-one mapping between code points and
  code units in any specific encoding and byte-order.

- By reserving those code points, it ensures that they cannot be
  accidentally used by the standard for something else.

- It makes it easier to talk about the entities: "U+D800 is a surrogate 
  code point reserved for UTF-16 surrogates", as opposed to "U+D800 isn't
  anything, but if it was something, it would be a code point reserved 
  for UTF-16 surrogates".

- Or worse, forcing us to talk in terms of code units (implementation)
  instead of abstract characters, which is painfully verbose:

  "0xD800 in Big Endian UTF-16, or 0x00D8 in Little Endian UTF-16, or 
  0x0000D800 in Big Endian UTF-32, or 0x00D80000 in Little Endian 
  UTF-16, doesn't map to any code point but is reserved for UTF-16
  surrogate pairs."


And, an entirely unforeseen purpose:

- It allows languages like Python to (ab)use surrogate code points for
  round-tripping file names which aren't valid Unicode.


[...]
>>> I'm afraid Python's choice may lead to exploitable security holes in
>>> Python programs.
>>
>> Feel free to back up that with an actual demonstration of an exploit,
>> rather than just FUD.
> 
> It might come as a surprise to programmers that pathnames cannot be
> UTF-encoded or displayed. 

Many things come as surprises to programmers, and many pathnames cannot be
UTF-encoded.

To be precise, Mac OS requires pathnames to be both valid and normalised
UTF-8, and it would be nice if that practice spread. But Windows only
requires pathnames to consist of UCS-2 code points, and Linux pathnames are
arbitrary bytes that may include characters which are illegal on Windows.
So you don't need to involve surrogates to have undecodable pathnames.


> Also, those situations might not show up 
> during testing but only with appropriately crafted input.

I'm not seeing a security exploit here.



-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From dieter at handshake.de  Mon Jan 23 03:42:12 2017
From: dieter at handshake.de (dieter)
Date: Mon, 23 Jan 2017 09:42:12 +0100
Subject: Problems with python3.6 on one system, but OK on another
References: <87a8akzkwj.fsf@Equus.decebal.nl>
Message-ID: <87inp6jhgb.fsf@handshake.de>

Cecil Westerhof <Cecil at decebal.nl> writes:

> I build python3.6 on two systems. On one system everything is OK:
> Python 3.6.0 (default, Jan 21 2017, 11:19:56) 
> [GCC 4.9.2] on linux
> Type "help", "copyright", "credits" or "license" for more information.
>
>
> But on another I get:
> Could not find platform dependent libraries <exec_prefix>
> Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
> Python 3.6.0 (default, Jan 21 2017, 12:20:38) 
> [GCC 4.8.5] on linux
> Type "help", "copyright", "credits" or "license" for more information.
>
> Probably not a big problem, but just wondering what is happening here.
> On both systems PYTHONHOME is not set and with the old version (3.4.5)
> I did/do not get this message.

A Python installation consists of two parts: the Python binary
(i.e. the Python interpreter) and the Python runtime library
(everything not built into the interpreter itself).

When you start Python, you effectively start the binary. This
then tries to locate the parts forming its runtime library.
Essentially, there are two parts: platform independent (i.e. Python
modules/packages) and platform dependent (usually shared objects
implemented in "C" or "C++"). The binary is using heuristics
to locate those parts, involving the (usually internal) variables
"prefix" and "exec_prefix" for the platform independent and dependent parts,
respectively.

On some platforms, the operating system allows a binary to determine
the full path it has been started from. On those platforms,
the above mentioned heuristics may use this path to locate the
runtime library parts. On other platforms, default values for
"prefix" and "exec_prefix" are determined during the Python generation.


As a consequnece, something must have gone wrong with the
generation or installation of your badly behaving Python.

To start the investigation, I would look at the binaries'
notion of "prefix" and "exec_prefix". You can find them via
>>> import sys
>>> sys.prefix, sys.exec_prefix

On a "*nix" like platform, you should find
the platform dependent parts of the runtime library
unter "<exec_prefix>/lib/Python<version>/lib-dynload".

Check whether this directory exists and is not empty.




From catalinfest at gmail.com  Mon Jan 23 05:38:02 2017
From: catalinfest at gmail.com (blue)
Date: Mon, 23 Jan 2017 02:38:02 -0800 (PST)
Subject: Adding colormaps?
In-Reply-To: <eea5oeF2d3aU1@mid.individual.net>
References: <eea5oeF2d3aU1@mid.individual.net>
Message-ID: <cb61631a-909f-4f4a-95c3-4164ae6629a5@googlegroups.com>

you have here a full example , for another version not significant changes:
http://matplotlib.org/examples/color/colormaps_reference.html


From Cecil at decebal.nl  Mon Jan 23 06:53:51 2017
From: Cecil at decebal.nl (Cecil Westerhof)
Date: Mon, 23 Jan 2017 12:53:51 +0100
Subject: Using python to start programs after logging in
References: <878tq6amvj.fsf@Equus.decebal.nl>
Message-ID: <874m0q6lgw.fsf@Equus.decebal.nl>

On Thursday 19 Jan 2017 20:08 CET, Cecil Westerhof wrote:

> I am writing a python program to start the programs that need to be
> started after logging in.

I published what I have until now at:
    https://github.com/CecilWesterhof/PythonScripts/blob/master/startPrograms.py

I do not mind some feedback. ;-)


Next step is to write a GUI program to maintain the database. That is
new territory for me.

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof


From mal at egenix.com  Mon Jan 23 09:11:38 2017
From: mal at egenix.com (M.-A. Lemburg)
Date: Mon, 23 Jan 2017 15:11:38 +0100
Subject: [Python-ideas] "Immutable Builder" Pattern and Operator
In-Reply-To: <e87e64b0-b2d8-8513-2671-f0e18b0dc97f@gmail.com>
References: <dbaa53be-d9ec-a5f6-4b9e-f5f16676b36d@gmail.com>
 <o63d7t$ied$1@blaine.gmane.org>
 <2127feaa-0a5b-8246-978f-6346dea554a2@gmail.com>
 <o64qc9$k3q$1@blaine.gmane.org>
 <e9f1547f-c5a6-045a-8716-7669a1662b32@gmail.com>
 <0654a27e-7200-c468-d4eb-17bef13b61d2@egenix.com>
 <e87e64b0-b2d8-8513-2671-f0e18b0dc97f@gmail.com>
Message-ID: <5032a807-75d5-d58f-5332-97ec22b0340a@egenix.com>

On 23.01.2017 14:28, Soni L. wrote:
> 
> 
> On 23/01/17 11:18 AM, M.-A. Lemburg wrote:
>> On 23.01.2017 14:05, Soni L. wrote:
>>> Yeah but the dotequals operator has many other benefits:
>>>
>>> long_name .= __call__  # cast to callable
>>> long_name .= wrapped  # unwrap
>>> etc
>>>
>>> And it also looks neat.
>> I don't see this an being a particular intuitive way of writing
>> such rather uncommon constructs.
>>
>> The syntax is not clear (what if you have an expression on the RHS)
>> and it doesn't save you much in writing (if long_name is too long
>> simply rebind it under a shorter name for the purpose of the code
>> block).
> 
> It's literally sugar for repeating the name and moving the dot to the
> right. I think it's clearer than most other compound operators in that
> it doesn't affect precedence rules.
> 
> `x += y`, for any code `y`, is equivalent to `x = x + (y)`, not `x = x +
> y`.
> 
> `x .= y`, for any code `y`, is equivalent to `x = x . y`, not `x = x .
> (y)`.

Well, then please consider these:

x .= y + z
x .= y * z
x .= y.z
x .= y.z()

>> Also note that rebinding different objects to the same name
>> in the same block is often poor style and can easily lead to
>> hard to track bugs.
>>
> 
> Rebinding different objects to the same name in rapid succession
> is fine.

Not in my book :-)

It may be fine if the object type stays the same or
in those few cases, where you want to accept multiple
different types for a parameter and then coerce these
to a type that you use in the rest of the code block.

But even in those cases, debugging becomes easier if
you keep the original binding in place (since you then
know where the new values originated).

This is not good style...

x = 'abc'
x = len(x)
x = [x, 1]
x = ''.join(str(a) for a in x)
print (x)

-- 
Marc-Andre Lemburg
eGenix.com

Professional Python Services directly from the Experts (#1, Jan 23 2017)
>>> Python Projects, Coaching and Consulting ...  http://www.egenix.com/
>>> Python Database Interfaces ...           http://products.egenix.com/
>>> Plone/Zope Database Interfaces ...           http://zope.egenix.com/
________________________________________________________________________

::: We implement business ideas - efficiently in both time and costs :::

   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/
                      http://www.malemburg.com/



From antoon.pardon at rece.vub.ac.be  Mon Jan 23 11:02:22 2017
From: antoon.pardon at rece.vub.ac.be (Antoon Pardon)
Date: Mon, 23 Jan 2017 17:02:22 +0100
Subject: How to create a socket.socket() object from a socket fd?
In-Reply-To: <o60vou$714$1@blaine.gmane.org>
References: <o60naq$bbm$1@blaine.gmane.org> <o60vou$714$1@blaine.gmane.org>
Message-ID: <f2a41bd2-7a04-9e6e-df12-38dfe216165e@rece.vub.ac.be>

Op 22-01-17 om 01:52 schreef Grant Edwards:
> Newsgroups: gmane.comp.python.general
> From: Grant Edwards <grant.b.edwards at gmail.com>
> Subject: Re: How to create a socket.socket() object from a socket fd?
> References: <o60naq$bbm$1 at blaine.gmane.org> <o60o2r$6cd$1 at blaine.gmane.org> <c7e3116f-6e9c-5343-6f82-c491fb917800 at python.org>
> Followup-To: 
>
> <rant>
>
> I'm still baffled why the standard library fromfd() code dup()s the
> descriptor.
>
> According to the comment in the CPython sources, the author of
> fromfd() is guessing that the user wants to be able to close the
> descriptor separately from the socket.
>
> If the user wanted the socket object to use a duplicate descriptor for
> some reason, the caller should call os.dup() -- it's only _eight_
> keystrokes.  Eight keystrokes that makes it obvious to anybody reading
> the code that there are now two descriptors and you have to close both
> the original descriptor and the socket.
>
> When you create a Python file object from a file descriptor using
> os.fdopen(), does it dup the descriptor?  No.  Would a reasonable
> person expect socket.fromfd() to duplicate the descriptor?  No.
>
> Should it?
>
> No.

The standard response to issues like this is:

   A foolish consistency is the hobgoblin of little minds

-- 
Antoon Pardon




From breamoreboy at gmail.com  Mon Jan 23 11:24:27 2017
From: breamoreboy at gmail.com (breamoreboy at gmail.com)
Date: Mon, 23 Jan 2017 08:24:27 -0800 (PST)
Subject: [Python-ideas] "Immutable Builder" Pattern and Operator
In-Reply-To: <mailman.28.1485180702.2473.python-list@python.org>
References: <dbaa53be-d9ec-a5f6-4b9e-f5f16676b36d@gmail.com>
 <o63d7t$ied$1@blaine.gmane.org>
 <2127feaa-0a5b-8246-978f-6346dea554a2@gmail.com>
 <o64qc9$k3q$1@blaine.gmane.org>
 <e9f1547f-c5a6-045a-8716-7669a1662b32@gmail.com>
 <0654a27e-7200-c468-d4eb-17bef13b61d2@egenix.com>
 <e87e64b0-b2d8-8513-2671-f0e18b0dc97f@gmail.com>
 <5032a807-75d5-d58f-5332-97ec22b0340a@egenix.com>
 <mailman.28.1485180702.2473.python-list@python.org>
Message-ID: <9d943553-2133-4b30-81ca-75a649900520@googlegroups.com>

On Monday, January 23, 2017 at 2:11:53 PM UTC, M.-A. Lemburg wrote:
> On 23.01.2017 14:28, Soni L. wrote:
> > 
> > 
> > On 23/01/17 11:18 AM, M.-A. Lemburg wrote:
> >> On 23.01.2017 14:05, Soni L. wrote:
> >>> Yeah but the dotequals operator has many other benefits:
> >>>
> >>> long_name .= __call__  # cast to callable
> >>> long_name .= wrapped  # unwrap
> >>> etc
> >>>
> >>> And it also looks neat.
> >> I don't see this an being a particular intuitive way of writing
> >> such rather uncommon constructs.
> >>
> >> The syntax is not clear (what if you have an expression on the RHS)
> >> and it doesn't save you much in writing (if long_name is too long
> >> simply rebind it under a shorter name for the purpose of the code
> >> block).
> > 
> > It's literally sugar for repeating the name and moving the dot to the
> > right. I think it's clearer than most other compound operators in that
> > it doesn't affect precedence rules.
> > 
> > `x += y`, for any code `y`, is equivalent to `x = x + (y)`, not `x = x +
> > y`.
> > 
> > `x .= y`, for any code `y`, is equivalent to `x = x . y`, not `x = x .
> > (y)`.
> 
> Well, then please consider these:
> 
> x .= y + z
> x .= y * z
> x .= y.z
> x .= y.z()
> 
> >> Also note that rebinding different objects to the same name
> >> in the same block is often poor style and can easily lead to
> >> hard to track bugs.
> >>
> > 
> > Rebinding different objects to the same name in rapid succession
> > is fine.
> 
> Not in my book :-)
> 
> It may be fine if the object type stays the same or
> in those few cases, where you want to accept multiple
> different types for a parameter and then coerce these
> to a type that you use in the rest of the code block.
> 
> But even in those cases, debugging becomes easier if
> you keep the original binding in place (since you then
> know where the new values originated).
> 
> This is not good style...
> 
> x = 'abc'
> x = len(x)
> x = [x, 1]
> x = ''.join(str(a) for a in x)
> print (x)
> 
> -- 
> Marc-Andre Lemburg
> eGenix.com
> 

The wrong list methinks :)

Kindest regards.

Mark Lawrence.


From grant.b.edwards at gmail.com  Mon Jan 23 12:00:49 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Mon, 23 Jan 2017 17:00:49 +0000 (UTC)
Subject: How to create a socket.socket() object from a socket fd?
References: <o60naq$bbm$1@blaine.gmane.org> <o60vou$714$1@blaine.gmane.org>
 <f2a41bd2-7a04-9e6e-df12-38dfe216165e@rece.vub.ac.be>
Message-ID: <o65cs1$tpf$1@blaine.gmane.org>

On 2017-01-23, Antoon Pardon <antoon.pardon at rece.vub.ac.be> wrote:
> Op 22-01-17 om 01:52 schreef Grant Edwards:
>> Newsgroups: gmane.comp.python.general
>> From: Grant Edwards <grant.b.edwards at gmail.com>
>> Subject: Re: How to create a socket.socket() object from a socket fd?
>> References: <o60naq$bbm$1 at blaine.gmane.org> <o60o2r$6cd$1 at blaine.gmane.org> <c7e3116f-6e9c-5343-6f82-c491fb917800 at python.org>
>> Followup-To: 
>>
>> <rant>
>>
>> I'm still baffled why the standard library fromfd() code dup()s the
>> descriptor.
>>
>> According to the comment in the CPython sources, the author of
>> fromfd() is guessing that the user wants to be able to close the
>> descriptor separately from the socket.
>>
>> If the user wanted the socket object to use a duplicate descriptor for
>> some reason, the caller should call os.dup() -- it's only _eight_
>> keystrokes.  Eight keystrokes that makes it obvious to anybody reading
>> the code that there are now two descriptors and you have to close both
>> the original descriptor and the socket.
>>
>> When you create a Python file object from a file descriptor using
>> os.fdopen(), does it dup the descriptor?  No.  Would a reasonable
>> person expect socket.fromfd() to duplicate the descriptor?  No.
>>
>> Should it?
>>
>> No.
>
> The standard response to issues like this is:
>
>    A foolish consistency is the hobgoblin of little minds

And wise consistency is the foundation of a good language design.

-- 
Grant Edwards               grant.b.edwards        Yow! I'm wet!  I'm wild!
                                  at               
                              gmail.com            



From breamoreboy at gmail.com  Mon Jan 23 12:24:45 2017
From: breamoreboy at gmail.com (breamoreboy at gmail.com)
Date: Mon, 23 Jan 2017 09:24:45 -0800 (PST)
Subject: How coding in Python is bad for you
Message-ID: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>

The article is here http://lenkaspace.net/index.php/blog/show/111

Kindest regards.

Mark Lawrence.


From rosuav at gmail.com  Mon Jan 23 12:34:19 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Jan 2017 04:34:19 +1100
Subject: How coding in Python is bad for you
In-Reply-To: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
Message-ID: <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>

On Tue, Jan 24, 2017 at 4:24 AM,  <breamoreboy at gmail.com> wrote:
> The article is here http://lenkaspace.net/index.php/blog/show/111

I would respond point-by-point if I thought the author had a clue.

ChrisA


From kalalsunnyy at gmail.com  Mon Jan 23 12:49:48 2017
From: kalalsunnyy at gmail.com (Sourabh Kalal)
Date: Mon, 23 Jan 2017 23:19:48 +0530
Subject: Is it possible to get the Physical memory address of a variable in
 python?
Message-ID: <CA+PdqeX4FsZGTmywOF-noZ8RNtEafj6HoTsKoMHCyHJ5zuUokg@mail.gmail.com>

how we can access the value from using id..
like x=10
id(x)
3235346364

how i can read value 10 using id 3235346364


From ethan at stoneleaf.us  Mon Jan 23 13:09:35 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Mon, 23 Jan 2017 10:09:35 -0800
Subject: How coding in Python is bad for you
In-Reply-To: <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
Message-ID: <588646DF.9050905@stoneleaf.us>

On 01/23/2017 09:34 AM, Chris Angelico wrote:
> On Tue, Jan 24, 2017 at 4:24 AM,  wrote:

>> The article is here http://lenkaspace.net/index.php/blog/show/111
>
> I would respond point-by-point if I thought the author had a clue.

Yeah, arguing with that person will be a waste of time.

--
~Ethan~


From rosuav at gmail.com  Mon Jan 23 13:49:06 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Jan 2017 05:49:06 +1100
Subject: Is it possible to get the Physical memory address of a variable
 in python?
In-Reply-To: <CA+PdqeX4FsZGTmywOF-noZ8RNtEafj6HoTsKoMHCyHJ5zuUokg@mail.gmail.com>
References: <CA+PdqeX4FsZGTmywOF-noZ8RNtEafj6HoTsKoMHCyHJ5zuUokg@mail.gmail.com>
Message-ID: <CAPTjJmpAdyC1gtz4nyR=Bjb_E0haWS1L1+YZW8LXvEhHvO4Ghg@mail.gmail.com>

On Tue, Jan 24, 2017 at 4:49 AM, Sourabh Kalal <kalalsunnyy at gmail.com> wrote:
> how we can access the value from using id..
> like x=10
> id(x)
> 3235346364
>
> how i can read value 10 using id 3235346364

No, you can't. That isn't a memory address - it's just a unique
identifier. Python doesn't have memory addresses.

ChrisA


From tjreedy at udel.edu  Mon Jan 23 13:59:52 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Mon, 23 Jan 2017 13:59:52 -0500
Subject: Is it possible to get the Physical memory address of a variable
 in python?
In-Reply-To: <CA+PdqeX4FsZGTmywOF-noZ8RNtEafj6HoTsKoMHCyHJ5zuUokg@mail.gmail.com>
References: <CA+PdqeX4FsZGTmywOF-noZ8RNtEafj6HoTsKoMHCyHJ5zuUokg@mail.gmail.com>
Message-ID: <o65jr5$tt2$1@blaine.gmane.org>

On 1/23/2017 12:49 PM, Sourabh Kalal wrote:
> how we can access the value from using id..
> like x=10
> id(x)
> 3235346364
>
> how i can read value 10 using id 3235346364

*In Python*, you cannot.  Ids are mainly for internal use of 
implementations.  Implementors also use them to test their implementation.

*CPython* comes with a module (ctypes) that can be used to muck around 
with interpreter internals, but it is definitely not for beginners.  I 
don't know about other implementations.

-- 
Terry Jan Reedy



From skip.montanaro at gmail.com  Mon Jan 23 14:05:58 2017
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Mon, 23 Jan 2017 13:05:58 -0600
Subject: Is it possible to get the Physical memory address of a variable
 in python?
In-Reply-To: <CAPTjJmpAdyC1gtz4nyR=Bjb_E0haWS1L1+YZW8LXvEhHvO4Ghg@mail.gmail.com>
References: <CA+PdqeX4FsZGTmywOF-noZ8RNtEafj6HoTsKoMHCyHJ5zuUokg@mail.gmail.com>
 <CAPTjJmpAdyC1gtz4nyR=Bjb_E0haWS1L1+YZW8LXvEhHvO4Ghg@mail.gmail.com>
Message-ID: <CANc-5UxLThm9JFaxcBWmFAFLN8L59jK3x3t5V+VsKMprwoMHeA@mail.gmail.com>

On Mon, Jan 23, 2017 at 12:49 PM, Chris Angelico <rosuav at gmail.com> wrote:
>
> On Tue, Jan 24, 2017 at 4:49 AM, Sourabh Kalal <kalalsunnyy at gmail.com> wrote:
> > how we can access the value from using id..
> > like x=10
> > id(x)
> > 3235346364
> >
> > how i can read value 10 using id 3235346364
>
> No, you can't. That isn't a memory address - it's just a unique
> identifier. Python doesn't have memory addresses.

Well, it might be, but that would be very implementation-dependent.
Any attempt to treat an id as a memory address and interpret the
object at that address as the beginning of a PyObject of any kind will
be fragile in the extreme. Even if you have two different
implementations at hand which both use memory addresses as convenient
ids, there's no guarantee that the address represents that start of a
CPython PyObject.

>>> hex(3235346364)
'0xc0d777bc'

There. *Now* you have an address. Hack to your heart's content. <wink>

Skip


From __peter__ at web.de  Mon Jan 23 14:34:06 2017
From: __peter__ at web.de (Peter Otten)
Date: Mon, 23 Jan 2017 20:34:06 +0100
Subject: Is it possible to get the Physical memory address of a variable
 in python?
References: <CA+PdqeX4FsZGTmywOF-noZ8RNtEafj6HoTsKoMHCyHJ5zuUokg@mail.gmail.com>
Message-ID: <o65lr9$h7f$1@blaine.gmane.org>

Sourabh Kalal wrote:

> how we can access the value from using id..
> like x=10
> id(x)
> 3235346364
> 
> how i can read value 10 using id 3235346364

Use ctypes:

$ python3
Python 3.4.3 (default, Nov 17 2016, 01:08:31) 
[GCC 4.8.4] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import ctypes
>>> ctypes.c_ubyte.from_address(id(10) + 24).value = 11
>>> 10 == 11
True

:)



From martin.schoon at gmail.com  Mon Jan 23 14:57:50 2017
From: martin.schoon at gmail.com (Martin =?UTF-8?Q?Sch=C3=B6=C3=B6n?=)
Date: 23 Jan 2017 19:57:50 GMT
Subject: Adding colormaps?
References: <eea5oeF2d3aU1@mid.individual.net>
 <cb61631a-909f-4f4a-95c3-4164ae6629a5@googlegroups.com>
Message-ID: <een5huF6fs4U1@mid.individual.net>

Den 2017-01-23 skrev blue <catalinfest at gmail.com>:
> you have here a full example , for another version not significant changes:
> http://matplotlib.org/examples/color/colormaps_reference.html

Thanks but this only shows how to use it once you have it. When I run
this code I get an error message telling it can't find any of those
new colormaps.

/Martin


From grant.b.edwards at gmail.com  Mon Jan 23 14:59:58 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Mon, 23 Jan 2017 19:59:58 +0000 (UTC)
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
Message-ID: <o65nbu$mre$1@blaine.gmane.org>

On 2017-01-23, breamoreboy at gmail.com <breamoreboy at gmail.com> wrote:

> The article is here http://lenkaspace.net/index.php/blog/show/111

I don't really think any of his points are valid, but one way that
programming in Python is bad for you:

 * It reduces your tolerance for progamming in PHP zero.  If you end
   up assigned to a PHP project, you end up miserable and unpleasant
   to work with or just plain unemployed.

-- 
Grant Edwards               grant.b.edwards        Yow! MERYL STREEP is my
                                  at               obstetrician!
                              gmail.com            



From torriem at gmail.com  Mon Jan 23 15:15:30 2017
From: torriem at gmail.com (Michael Torrie)
Date: Mon, 23 Jan 2017 13:15:30 -0700
Subject: How coding in Python is bad for you
In-Reply-To: <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
Message-ID: <665f8eaf-6fbe-958d-a0b0-2bfc1f263327@gmail.com>

On 01/23/2017 10:34 AM, Chris Angelico wrote:
> I would respond point-by-point if I thought the author had a clue.

Yeah a pretty bizarre, flame-bait blog post.  Glad I use an ad-blocker
as a matter of course. I'm uncertain as to why Mark chose to post that
particular little gem to the list.  It's neither thought-provoking nor
terribly insightful.



From rosuav at gmail.com  Mon Jan 23 15:17:32 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Jan 2017 07:17:32 +1100
Subject: Is it possible to get the Physical memory address of a variable
 in python?
In-Reply-To: <CANc-5UxLThm9JFaxcBWmFAFLN8L59jK3x3t5V+VsKMprwoMHeA@mail.gmail.com>
References: <CA+PdqeX4FsZGTmywOF-noZ8RNtEafj6HoTsKoMHCyHJ5zuUokg@mail.gmail.com>
 <CAPTjJmpAdyC1gtz4nyR=Bjb_E0haWS1L1+YZW8LXvEhHvO4Ghg@mail.gmail.com>
 <CANc-5UxLThm9JFaxcBWmFAFLN8L59jK3x3t5V+VsKMprwoMHeA@mail.gmail.com>
Message-ID: <CAPTjJmrQnfHZ37f_mBnpSa3PtwjYR+VOb4eEkOd__HFwR2Ca5Q@mail.gmail.com>

On Tue, Jan 24, 2017 at 6:05 AM, Skip Montanaro
<skip.montanaro at gmail.com> wrote:
> On Mon, Jan 23, 2017 at 12:49 PM, Chris Angelico <rosuav at gmail.com> wrote:
>>
>> On Tue, Jan 24, 2017 at 4:49 AM, Sourabh Kalal <kalalsunnyy at gmail.com> wrote:
>> > how we can access the value from using id..
>> > like x=10
>> > id(x)
>> > 3235346364
>> >
>> > how i can read value 10 using id 3235346364
>>
>> No, you can't. That isn't a memory address - it's just a unique
>> identifier. Python doesn't have memory addresses.
>
> Well, it might be, but that would be very implementation-dependent.
> Any attempt to treat an id as a memory address and interpret the
> object at that address as the beginning of a PyObject of any kind will
> be fragile in the extreme. Even if you have two different
> implementations at hand which both use memory addresses as convenient
> ids, there's no guarantee that the address represents that start of a
> CPython PyObject.
>
>>>> hex(3235346364)
> '0xc0d777bc'
>
> There. *Now* you have an address. Hack to your heart's content. <wink>

No, you now have a hexadecimal representation of an integer. Memory
addresses are integers; Python object identifiers are also integers.
The fact that they may happen to correspond *in CPython* is basically
a coincidence.

In a language like C, where pointers and memory addresses are real
things, you can work with an integer and dereference it to get the
data at that address. In BASIC, where I first learned programming, you
have specific instructions to mess with memory (I have fond memories
of messing around with segment zero to change the status of Caps Lock
etc, and of peeking and poking in video memory, and stuff). But in
Python, that exists only in ctypes, and that only because ctypes is
basically C.

rosuav at sikorsky:~$ python3
Python 3.7.0a0 (default:cebc9c7ad195, Jan 24 2017, 06:55:19)
[GCC 6.2.0 20161027] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> objs = [object() for _ in range(10)]
>>> [id(x) for x in objs]
[140652901773504, 140652901773520, 140652901773536, 140652901773552,
140652901773568, 140652901773584, 140652901773600, 140652901773616,
140652901773632, 140652901773648]

These could well be memory addresses, but...

>>> objs = [object() for _ in range(10)]
>>> [id(x) for x in objs]
[2, 3, 4, 5, 6, 7, 8, 9, 10, 11]

... these almost certainly aren't. They are, however, unique integer
values (the 'objs' list guarantees that all objects are simultaneously
alive, ergo the IDs must be unique). Other Python implementations are
free to do what they like. Quite a few do seem to use something like a
memory address (uPy, PyPy, PyPyJS), but not all:

Brython 3.3.0 on Netscape 5.0 (X11; Linux x86_64) AppleWebKit/537.36
(KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36
>>> objs = [object() for _ in range(10)]
>>> [id(x) for x in objs]
[54, 55, 56, 57, 58, 59, 60, 61, 62, 63]

There's basically no way to go from an ID to the object. If you know
what data type it is (eg an integer, as in the OP's example), you can
reach in and grab the contents, but there's no way to write this
function:

def deref(id):
    ... # ????
assert deref(id(x)) is x

The best you could do, in terms of parlour tricks, is to test it only
on small integers, where ctypes can get you the value of the integer,
and thanks to small-int-caching, it will actually be the same object.
But it won't work for larger integers.

It's not a pointer.

ChrisA


From rosuav at gmail.com  Mon Jan 23 15:19:42 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Jan 2017 07:19:42 +1100
Subject: How coding in Python is bad for you
In-Reply-To: <o65nbu$mre$1@blaine.gmane.org>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <o65nbu$mre$1@blaine.gmane.org>
Message-ID: <CAPTjJmqh_jTGyZ0_v-JELxM--H=b-2azB3aSC5fSq1Hk38CpXQ@mail.gmail.com>

On Tue, Jan 24, 2017 at 6:59 AM, Grant Edwards
<grant.b.edwards at gmail.com> wrote:
> On 2017-01-23, breamoreboy at gmail.com <breamoreboy at gmail.com> wrote:
>
>> The article is here http://lenkaspace.net/index.php/blog/show/111
>
> I don't really think any of his points are valid, but one way that
> programming in Python is bad for you:
>
>  * It reduces your tolerance for progamming in PHP zero.  If you end
>    up assigned to a PHP project, you end up miserable and unpleasant
>    to work with or just plain unemployed.

I believe that's "bad for you" in the sense that chocolate is bad for you.

It isn't.

ChrisA


From torriem at gmail.com  Mon Jan 23 15:24:35 2017
From: torriem at gmail.com (Michael Torrie)
Date: Mon, 23 Jan 2017 13:24:35 -0700
Subject: Is it possible to get the Physical memory address of a variable
 in python?
In-Reply-To: <CA+PdqeX4FsZGTmywOF-noZ8RNtEafj6HoTsKoMHCyHJ5zuUokg@mail.gmail.com>
References: <CA+PdqeX4FsZGTmywOF-noZ8RNtEafj6HoTsKoMHCyHJ5zuUokg@mail.gmail.com>
Message-ID: <8d84a398-aa19-3819-5408-0738555a5455@gmail.com>

On 01/23/2017 10:49 AM, Sourabh Kalal wrote:
> how we can access the value from using id..
> like x=10
> id(x)
> 3235346364
> 
> how i can read value 10 using id 3235346364

Many objects in python such as numbers like 10 or strings are immutable;
they can never be altered once called into existance.  When you assign
to a variable, you are binding the variable name to an object.  So if
you later took your x variable and re-assigned it to value 11, the id of
x would change to reflect this new object 11.

If you could find the memory address in your example where 10 is stored,
and then modified it, you could mess up a lot of things because the
interpreter is free to optimize and to use the same 10 object every
places where 10 is assigned to a variable.



From skip.montanaro at gmail.com  Mon Jan 23 15:26:31 2017
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Mon, 23 Jan 2017 14:26:31 -0600
Subject: Is it possible to get the Physical memory address of a variable
 in python?
In-Reply-To: <CAPTjJmrQnfHZ37f_mBnpSa3PtwjYR+VOb4eEkOd__HFwR2Ca5Q@mail.gmail.com>
References: <CA+PdqeX4FsZGTmywOF-noZ8RNtEafj6HoTsKoMHCyHJ5zuUokg@mail.gmail.com>
 <CAPTjJmpAdyC1gtz4nyR=Bjb_E0haWS1L1+YZW8LXvEhHvO4Ghg@mail.gmail.com>
 <CANc-5UxLThm9JFaxcBWmFAFLN8L59jK3x3t5V+VsKMprwoMHeA@mail.gmail.com>
 <CAPTjJmrQnfHZ37f_mBnpSa3PtwjYR+VOb4eEkOd__HFwR2Ca5Q@mail.gmail.com>
Message-ID: <CANc-5UxVyGA7YUZ8EAgFB+BT9KnFAY+JywY59P2xXdzQFsq0Kg@mail.gmail.com>

On Mon, Jan 23, 2017 at 2:17 PM, Chris Angelico <rosuav at gmail.com> wrote:
>> There. *Now* you have an address. Hack to your heart's content. <wink>
>
> No, you now have a hexadecimal representation of an integer.

You missed my attempt at levity, I think.

S


From rosuav at gmail.com  Mon Jan 23 15:32:29 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Jan 2017 07:32:29 +1100
Subject: Is it possible to get the Physical memory address of a variable
 in python?
In-Reply-To: <CANc-5UxVyGA7YUZ8EAgFB+BT9KnFAY+JywY59P2xXdzQFsq0Kg@mail.gmail.com>
References: <CA+PdqeX4FsZGTmywOF-noZ8RNtEafj6HoTsKoMHCyHJ5zuUokg@mail.gmail.com>
 <CAPTjJmpAdyC1gtz4nyR=Bjb_E0haWS1L1+YZW8LXvEhHvO4Ghg@mail.gmail.com>
 <CANc-5UxLThm9JFaxcBWmFAFLN8L59jK3x3t5V+VsKMprwoMHeA@mail.gmail.com>
 <CAPTjJmrQnfHZ37f_mBnpSa3PtwjYR+VOb4eEkOd__HFwR2Ca5Q@mail.gmail.com>
 <CANc-5UxVyGA7YUZ8EAgFB+BT9KnFAY+JywY59P2xXdzQFsq0Kg@mail.gmail.com>
Message-ID: <CAPTjJmpfsZiJOeQ9s-wnRmPJPz+RhsBKGvbw27pEmAEv6zECoA@mail.gmail.com>

On Tue, Jan 24, 2017 at 7:26 AM, Skip Montanaro
<skip.montanaro at gmail.com> wrote:
> On Mon, Jan 23, 2017 at 2:17 PM, Chris Angelico <rosuav at gmail.com> wrote:
>>> There. *Now* you have an address. Hack to your heart's content. <wink>
>>
>> No, you now have a hexadecimal representation of an integer.
>
> You missed my attempt at levity, I think.

Ahh, I guess I did.

Sadly, it is all too true that there is no statement so ridiculous
that it's unquestionably a joke. An ill-informed person could easily
come out with exactly the same comment. :(

ChrisA


From alister.ware at ntlworld.com  Mon Jan 23 15:32:49 2017
From: alister.ware at ntlworld.com (alister)
Date: Mon, 23 Jan 2017 20:32:49 GMT
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <o65nbu$mre$1@blaine.gmane.org>
 <CAPTjJmqh_jTGyZ0_v-JELxM--H=b-2azB3aSC5fSq1Hk38CpXQ@mail.gmail.com>
 <mailman.42.1485203128.2473.python-list@python.org>
Message-ID: <RLthA.146356$c41.2628@fx40.am4>

On Tue, 24 Jan 2017 07:19:42 +1100, Chris Angelico wrote:

> On Tue, Jan 24, 2017 at 6:59 AM, Grant Edwards
> <grant.b.edwards at gmail.com> wrote:
>> On 2017-01-23, breamoreboy at gmail.com <breamoreboy at gmail.com> wrote:
>>
>>> The article is here http://lenkaspace.net/index.php/blog/show/111
>>
>> I don't really think any of his points are valid, but one way that
>> programming in Python is bad for you:
>>
>>  * It reduces your tolerance for progamming in PHP zero.  If you end
>>    up assigned to a PHP project, you end up miserable and unpleasant to
>>    work with or just plain unemployed.
> 
> I believe that's "bad for you" in the sense that chocolate is bad for
> you.
> 
> It isn't.
> 
> ChrisA

chocolate is a poison (lethal dose for a human approx 22lb)



-- 
Make headway at work.  Continue to let things deteriorate at home.


From sjeik_appie at hotmail.com  Mon Jan 23 15:35:52 2017
From: sjeik_appie at hotmail.com (Albert-Jan Roskam)
Date: Mon, 23 Jan 2017 20:35:52 +0000
Subject: Adding colormaps?
In-Reply-To: <eehvdlFtgutU1@mid.individual.net>
References: <eea5oeF2d3aU1@mid.individual.net>
 <P7LgA.125151$Zf5.106498@fx41.am4>,<eehvdlFtgutU1@mid.individual.net>
Message-ID: <VI1PR1001MB1149EA21E872769188FCA40083720@VI1PR1001MB1149.EURPRD10.PROD.OUTLOOK.COM>

(sorry for top-posting)
I does not appear to be possible in matplolibrc (1). But you can use matplotlib.cm.register_cmap to register new cmaps (2) such as these (3).

(Note: I did not try this)

(1)http://matplotlib.org/1.4.0/users/customizing.html
(2)http://matplotlib.org/api/cm_api.html
(3)https://github.com/BIDS/colormap/blob/master/colormaps.py
________________________________
From: Python-list <python-list-bounces+sjeik_appie=hotmail.com at python.org> on behalf of Martin Sch??n <martin.schoon at gmail.com>
Sent: Saturday, January 21, 2017 8:42:29 PM
To: python-list at python.org
Subject: Re: Adding colormaps?

Den 2017-01-21 skrev Gilmeh Serda <gilmeh.serdah at nothing.here.invalid>:
> On Wed, 18 Jan 2017 21:41:34 +0000, Martin Sch??n wrote:
>
>> What I would like to do is to add the perceptually uniform sequential
>> colormaps introduced in version 1.5.something. I would like to do this
>> without breaking my Debian system in which Matplotlib version 1.4.2 is
>> the newest version available in the repo.
>
> Haven't checked, but I assume you can get the source. Compile it but
> don't install it and then use the result in virtualenv, maybe?
>
I am hoping for directions to a config file to download and place
somewhere...

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


From jon+usenet at unequivocal.eu  Mon Jan 23 15:39:26 2017
From: jon+usenet at unequivocal.eu (Jon Ribbens)
Date: Mon, 23 Jan 2017 20:39:26 -0000 (UTC)
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <o65nbu$mre$1@blaine.gmane.org>
 <CAPTjJmqh_jTGyZ0_v-JELxM--H=b-2azB3aSC5fSq1Hk38CpXQ@mail.gmail.com>
 <mailman.42.1485203128.2473.python-list@python.org>
 <RLthA.146356$c41.2628@fx40.am4>
Message-ID: <slrno8cqj2.2ca.jon+usenet@sable.unequivocal.eu>

On 2017-01-23, alister <alister.ware at ntlworld.com> wrote:
> On Tue, 24 Jan 2017 07:19:42 +1100, Chris Angelico wrote:
>> I believe that's "bad for you" in the sense that chocolate is bad for
>> you.
>> 
>> It isn't.
>
> chocolate is a poison (lethal dose for a human approx 22lb)

That's a meaningless statement. *Everything* is a poison
in sufficient quantities.


From sjeik_appie at hotmail.com  Mon Jan 23 15:44:29 2017
From: sjeik_appie at hotmail.com (Albert-Jan Roskam)
Date: Mon, 23 Jan 2017 20:44:29 +0000
Subject: How coding in Python is bad for you
In-Reply-To: <RLthA.146356$c41.2628@fx40.am4>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <o65nbu$mre$1@blaine.gmane.org>
 <CAPTjJmqh_jTGyZ0_v-JELxM--H=b-2azB3aSC5fSq1Hk38CpXQ@mail.gmail.com>
 <mailman.42.1485203128.2473.python-list@python.org>,
 <RLthA.146356$c41.2628@fx40.am4>
Message-ID: <VI1PR1001MB11494DD6070EC48AE27D8EB883720@VI1PR1001MB1149.EURPRD10.PROD.OUTLOOK.COM>

sola dosis facit venenum ~ Paracelsus (1493-1541)
________________________________
From: Python-list <python-list-bounces+sjeik_appie=hotmail.com at python.org> on behalf of alister <alister.ware at ntlworld.com>
Sent: Monday, January 23, 2017 8:32:49 PM
To: python-list at python.org
Subject: Re: How coding in Python is bad for you

On Tue, 24 Jan 2017 07:19:42 +1100, Chris Angelico wrote:

> On Tue, Jan 24, 2017 at 6:59 AM, Grant Edwards
> <grant.b.edwards at gmail.com> wrote:
>> On 2017-01-23, breamoreboy at gmail.com <breamoreboy at gmail.com> wrote:
>>
>>> The article is here http://lenkaspace.net/index.php/blog/show/111
>>
>> I don't really think any of his points are valid, but one way that
>> programming in Python is bad for you:
>>
>>  * It reduces your tolerance for progamming in PHP zero.  If you end
>>    up assigned to a PHP project, you end up miserable and unpleasant to
>>    work with or just plain unemployed.
>
> I believe that's "bad for you" in the sense that chocolate is bad for
> you.
>
> It isn't.
>
> ChrisA

chocolate is a poison (lethal dose for a human approx 22lb)



--
Make headway at work.  Continue to let things deteriorate at home.
--
https://mail.python.org/mailman/listinfo/python-list


From amorawski at magna-power.com  Mon Jan 23 16:04:01 2017
From: amorawski at magna-power.com (Adam M)
Date: Mon, 23 Jan 2017 13:04:01 -0800 (PST)
Subject: How coding in Python is bad for you
In-Reply-To: <slrno8cqj2.2ca.jon+usenet@sable.unequivocal.eu>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <o65nbu$mre$1@blaine.gmane.org>
 <CAPTjJmqh_jTGyZ0_v-JELxM--H=b-2azB3aSC5fSq1Hk38CpXQ@mail.gmail.com>
 <mailman.42.1485203128.2473.python-list@python.org>
 <RLthA.146356$c41.2628@fx40.am4>
 <slrno8cqj2.2ca.jon+usenet@sable.unequivocal.eu>
Message-ID: <19df8402-c187-4250-b7f8-66d7e02475c0@googlegroups.com>

On Monday, January 23, 2017 at 3:41:17 PM UTC-5, Jon Ribbens wrote:
> On 2017-01-23, alister <ali....re at ntlworld.com> wrote:
> > On Tue, 24 Jan 2017 07:19:42 +1100, Chris Angelico wrote:
> >> I believe that's "bad for you" in the sense that chocolate is bad for
> >> you.
> >> 
> >> It isn't.
> >
> > chocolate is a poison (lethal dose for a human approx 22lb)
> 
> That's a meaningless statement. *Everything* is a poison
> in sufficient quantities.

I think you need to calibrate your sarcasm filter ;-). By the way coffee  is also dangerous - especially in 50lbs bags (when it hits you).


From rosuav at gmail.com  Mon Jan 23 16:11:02 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Jan 2017 08:11:02 +1100
Subject: How coding in Python is bad for you
In-Reply-To: <19df8402-c187-4250-b7f8-66d7e02475c0@googlegroups.com>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <o65nbu$mre$1@blaine.gmane.org>
 <CAPTjJmqh_jTGyZ0_v-JELxM--H=b-2azB3aSC5fSq1Hk38CpXQ@mail.gmail.com>
 <mailman.42.1485203128.2473.python-list@python.org>
 <RLthA.146356$c41.2628@fx40.am4>
 <slrno8cqj2.2ca.jon+usenet@sable.unequivocal.eu>
 <19df8402-c187-4250-b7f8-66d7e02475c0@googlegroups.com>
Message-ID: <CAPTjJmrz7L=OXAY9+t+yXs-XDu5C9QsR8cJVrbU8O86TsA8J9w@mail.gmail.com>

On Tue, Jan 24, 2017 at 8:04 AM, Adam M <amorawski at magna-power.com> wrote:
> On Monday, January 23, 2017 at 3:41:17 PM UTC-5, Jon Ribbens wrote:
>> On 2017-01-23, alister <ali....re at ntlworld.com> wrote:
>> > On Tue, 24 Jan 2017 07:19:42 +1100, Chris Angelico wrote:
>> >> I believe that's "bad for you" in the sense that chocolate is bad for
>> >> you.
>> >>
>> >> It isn't.
>> >
>> > chocolate is a poison (lethal dose for a human approx 22lb)
>>
>> That's a meaningless statement. *Everything* is a poison
>> in sufficient quantities.
>
> I think you need to calibrate your sarcasm filter ;-). By the way coffee  is also dangerous - especially in 50lbs bags (when it hits you).

Or with sufficient velocity. The LD50 of lead is about 450mg/kg [1],
which means that a typical 70kg human could ingest about 31 grams of
lead and have a fifty-fifty chance of survival. But just a few grams
of lead at the speed of sound will probably kill you. [2]

ChrisA

[1] http://whs.rocklinusd.org/documents/Science/Lethal_Dose_Table.pdf
[2] https://xkcd.com/444/


From breamoreboy at gmail.com  Mon Jan 23 16:21:00 2017
From: breamoreboy at gmail.com (breamoreboy at gmail.com)
Date: Mon, 23 Jan 2017 13:21:00 -0800 (PST)
Subject: Is it possible to get the Physical memory address of a variable
 in python?
In-Reply-To: <mailman.32.1485194369.2473.python-list@python.org>
References: <CA+PdqeX4FsZGTmywOF-noZ8RNtEafj6HoTsKoMHCyHJ5zuUokg@mail.gmail.com>
 <mailman.32.1485194369.2473.python-list@python.org>
Message-ID: <2517f772-2a0f-45f6-8ab1-ceb3548cc876@googlegroups.com>

On Monday, January 23, 2017 at 5:59:42 PM UTC, Sourabh Kalal wrote:
> how we can access the value from using id..
> like x=10
> id(x)
> 3235346364
> 
> how i can read value 10 using id 3235346364

What are you trying to achieve here?  If you'd explain that rather than how you're trying to achieve it you're likely to get better answers.

Kindest regards.

Mark Lawrence.


From subhabangalore at gmail.com  Mon Jan 23 16:23:38 2017
From: subhabangalore at gmail.com (subhabangalore at gmail.com)
Date: Mon, 23 Jan 2017 13:23:38 -0800 (PST)
Subject: String Replacement
Message-ID: <fde3f369-8897-4d6d-a79f-15a4dc159d19@googlegroups.com>

I have a string like 

"Trump is $ the president of USA % Obama was $ the president of USA % Putin is $ the premier of Russia%"

Here, I want to extract the portions from $...%, which would be

"the president of USA", 
"the president of USA", 
"the premier of Russia"

and would work some post extraction jobs, like I may split them or annotate them and may replace them
back to its own position with the edited string.

In the end it may look like

"Trump is  the/DET president/NN of/PREP USA/NN  Obama was  the/DET president/NN of/PREP USA/NN Putin is  the/DET premier/NN of/PREP Russia/NN"

I am working around replace and re.sub 

If any one may kindly suggest.

I am using Python2.7.12 on MS-Windows 7

Thanking in Advance


From rosuav at gmail.com  Mon Jan 23 16:30:45 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Jan 2017 08:30:45 +1100
Subject: String Replacement
In-Reply-To: <fde3f369-8897-4d6d-a79f-15a4dc159d19@googlegroups.com>
References: <fde3f369-8897-4d6d-a79f-15a4dc159d19@googlegroups.com>
Message-ID: <CAPTjJmoMFBWytHpdVVJSyUpUF8h+trbuhtcACxXTqEhGRg2OBw@mail.gmail.com>

On Tue, Jan 24, 2017 at 8:23 AM,  <subhabangalore at gmail.com> wrote:
> I have a string like
>
> "Trump is $ the president of USA % Obama was $ the president of USA % Putin is $ the premier of Russia%"
>
> Here, I want to extract the portions from $...%, which would be
>
> "the president of USA",
> "the president of USA",
> "the premier of Russia"
>
> and would work some post extraction jobs, like I may split them or annotate them and may replace them
> back to its own position with the edited string.
>

The simplest solution would be a regex. Have a shot at it and see how
you go; if you get stuck, post code.

> I am using Python2.7.12 on MS-Windows 7

Any particular reason you're not using Python 3?

ChrisA


From best_lay at yahoo.com  Mon Jan 23 16:39:58 2017
From: best_lay at yahoo.com (Wildman)
Date: Mon, 23 Jan 2017 15:39:58 -0600
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <o65nbu$mre$1@blaine.gmane.org>
 <CAPTjJmqh_jTGyZ0_v-JELxM--H=b-2azB3aSC5fSq1Hk38CpXQ@mail.gmail.com>
 <mailman.42.1485203128.2473.python-list@python.org>
 <RLthA.146356$c41.2628@fx40.am4>
 <slrno8cqj2.2ca.jon+usenet@sable.unequivocal.eu>
Message-ID: <7YSdnSVIpN2z5RvFnZ2dnUU7-WmdnZ2d@giganews.com>

On Mon, 23 Jan 2017 20:39:26 +0000, Jon Ribbens wrote:

> On 2017-01-23, alister <alister.ware at ntlworld.com> wrote:
>> On Tue, 24 Jan 2017 07:19:42 +1100, Chris Angelico wrote:
>>> I believe that's "bad for you" in the sense that chocolate is bad for
>>> you.
>>> 
>>> It isn't.
>>
>> chocolate is a poison (lethal dose for a human approx 22lb)
> 
> That's a meaningless statement. *Everything* is a poison
> in sufficient quantities.

Yes, even water.

-- 
<Wildman> GNU/Linux user #557453
The cow died so I don't need your bull!


From bc at freeuk.com  Mon Jan 23 16:55:01 2017
From: bc at freeuk.com (BartC)
Date: Mon, 23 Jan 2017 21:55:01 +0000
Subject: How coding in Python is bad for you
In-Reply-To: <mailman.31.1485193216.2473.python-list@python.org>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
Message-ID: <o65u0i$b4c$1@dont-email.me>

On 23/01/2017 17:34, Chris Angelico wrote:
> On Tue, Jan 24, 2017 at 4:24 AM,  <breamoreboy at gmail.com> wrote:
>> The article is here http://lenkaspace.net/index.php/blog/show/111
>
> I would respond point-by-point if I thought the author had a clue.

I thought points 1 to 4 were valid, in that the assertions were true.

Point 5 (memory leaks) I haven't experienced.

Point 6 (libraries depending on libraries...) is probably true in other 
languages too.

Point 7 (Python claiming to be general purpose) I don't have an opinion 
about.

-- 
Bartc


From rosuav at gmail.com  Mon Jan 23 17:09:51 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Jan 2017 09:09:51 +1100
Subject: How coding in Python is bad for you
In-Reply-To: <o65u0i$b4c$1@dont-email.me>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
Message-ID: <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>

On Tue, Jan 24, 2017 at 8:55 AM, BartC <bc at freeuk.com> wrote:
> On 23/01/2017 17:34, Chris Angelico wrote:
>>
>> On Tue, Jan 24, 2017 at 4:24 AM,  <breamoreboy at gmail.com> wrote:
>>>
>>> The article is here http://lenkaspace.net/index.php/blog/show/111
>>
>>
>> I would respond point-by-point if I thought the author had a clue.
>
>
> I thought points 1 to 4 were valid, in that the assertions were true.

1 is wrong - there is structure, same as in every language. Or if it's
true, it's true in every language. 2 is also trivially true - you can
ALWAYS define variables wrongly. Yes, okay, so you don't have data
type checking, but that's only going to catch a specific subset of
errors. 3, well, okay. But if you get your indentation wrong in C++,
Java, etc, it should fail code review. 4 is flat out wrong.

> Point 5 (memory leaks) I haven't experienced.

Me neither - Python doesn't leak memory, and in fact CPython has leak
testing as part of its test suite. You are *far* more likely to
experience memory leaks in a C program than a Python one.

> Point 6 (libraries depending on libraries...) is probably true in other
> languages too.

And far more so. He says "(because, let's face it, Python by itself
doesn't support much)" - that's flat wrong. Python's standard library
is _excellent_ compared to many other languages'.

> Point 7 (Python claiming to be general purpose) I don't have an opinion
> about.

He doesn't even have a decent point in there. We're so insular because
we think Python is general? Huh?

> But for a big project, Python code can become a big mess very quickly,
> unless there is an experienced programmer to guide the development process.

So... can you name a language where a bunch of novices can build a
huge project with no scaling troubles? Honestly? Get yourself an
expert, at least in an advisory role.

Not one of his points is truly valid, other than the ones that are
trivially valid and true of every language.

ChrisA


From ethan at stoneleaf.us  Mon Jan 23 17:18:26 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Mon, 23 Jan 2017 14:18:26 -0800
Subject: How coding in Python is bad for you
In-Reply-To: <o65u0i$b4c$1@dont-email.me>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
Message-ID: <58868132.8070500@stoneleaf.us>

On 01/23/2017 01:55 PM, BartC wrote:
> On 23/01/2017 17:34, Chris Angelico wrote:
>> On Tue, Jan 24, 2017 at 4:24 AM, breamoreboy wrote:

>>> The article is here http://lenkaspace.net/index.php/blog/show/111
>>
>> I would respond point-by-point if I thought the author had a clue.
>
> I thought points 1 to 4 were valid, in that the assertions were true.

Seriously?

1. Structure - having a predefined structure does not keep your program
     from becoming a mess.

2. Lying - any language can have poorly named parameters.

3. Meaning based on indentation - flat-out wrong: x += 1 does exactly
    what it says, whether it's indented once, twice, or seven times.

4. No compiler & no feedback - Python code is compiled, and feedback is
    available via linters, mypy, etc.

The only thing proven by that essay is that Lenka is a lousy Python
programmer.  He (she?) didn't even tag the article with Python, instead
using the tags Java, C++, and ActionScript.

--
~Ethan~


From ethan at stoneleaf.us  Mon Jan 23 17:50:35 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Mon, 23 Jan 2017 14:50:35 -0800
Subject: How to create a socket.socket() object from a socket fd?
In-Reply-To: <o65cs1$tpf$1@blaine.gmane.org>
References: <o60naq$bbm$1@blaine.gmane.org> <o60vou$714$1@blaine.gmane.org>
 <f2a41bd2-7a04-9e6e-df12-38dfe216165e@rece.vub.ac.be>
 <o65cs1$tpf$1@blaine.gmane.org>
Message-ID: <588688BB.3040900@stoneleaf.us>

On 01/23/2017 09:00 AM, Grant Edwards wrote:
> On 2017-01-23, Antoon Pardon wrote:

>> The standard response to issues like this is:
>>
>>     A foolish consistency is the hobgoblin of little minds
>
> And wise consistency is the foundation of a good language design.

Otherwise known as:  if there's not a /very/ good reason to make them different, make them the same.

--
~Ethan~


From none at invalid.com  Mon Jan 23 17:55:19 2017
From: none at invalid.com (mm0fmf)
Date: Mon, 23 Jan 2017 22:55:19 +0000
Subject: How coding in Python is bad for you
In-Reply-To: <19df8402-c187-4250-b7f8-66d7e02475c0@googlegroups.com>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <o65nbu$mre$1@blaine.gmane.org>
 <CAPTjJmqh_jTGyZ0_v-JELxM--H=b-2azB3aSC5fSq1Hk38CpXQ@mail.gmail.com>
 <mailman.42.1485203128.2473.python-list@python.org>
 <RLthA.146356$c41.2628@fx40.am4>
 <slrno8cqj2.2ca.jon+usenet@sable.unequivocal.eu>
 <19df8402-c187-4250-b7f8-66d7e02475c0@googlegroups.com>
Message-ID: <o661hk$nvk$1@dont-email.me>

On 23/01/2017 21:04, Adam M wrote:
> On Monday, January 23, 2017 at 3:41:17 PM UTC-5, Jon Ribbens wrote:
>> On 2017-01-23, alister <ali....re at ntlworld.com> wrote:
>>> On Tue, 24 Jan 2017 07:19:42 +1100, Chris Angelico wrote:
>>>> I believe that's "bad for you" in the sense that chocolate is bad for
>>>> you.
>>>>
>>>> It isn't.
>>>
>>> chocolate is a poison (lethal dose for a human approx 22lb)
>>
>> That's a meaningless statement. *Everything* is a poison
>> in sufficient quantities.
>
> I think you need to calibrate your sarcasm filter ;-). By the way coffee  is also dangerous - especially in 50lbs bags (when it hits you).
>
What a way to go...

50lbs of coffee beans made into espresso and 22lbs of chocolate to eat 
with all those tiny cups.

Yes, the article is clickbait which is why I delight in reading them 
with ad and script blockers turned up to maximum.




From info at tundraware.com  Mon Jan 23 18:15:20 2017
From: info at tundraware.com (Tim Daneliuk)
Date: Mon, 23 Jan 2017 17:15:20 -0600
Subject: How coding in Python is bad for you
In-Reply-To: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
Message-ID: <8dfild-vgj.ln1@oceanview.tundraware.com>

On 01/23/2017 11:24 AM, breamoreboy at gmail.com wrote:
> The article is here http://lenkaspace.net/index.php/blog/show/111
> 
> Kindest regards.
> 
> Mark Lawrence.
> 

Beyond silly.  Languages - like all tools - can be used properly or badly.


From info at tundraware.com  Mon Jan 23 18:16:28 2017
From: info at tundraware.com (Tim Daneliuk)
Date: Mon, 23 Jan 2017 17:16:28 -0600
Subject: How coding in Python is bad for you
In-Reply-To: <mailman.42.1485203128.2473.python-list@python.org>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <o65nbu$mre$1@blaine.gmane.org>
 <CAPTjJmqh_jTGyZ0_v-JELxM--H=b-2azB3aSC5fSq1Hk38CpXQ@mail.gmail.com>
 <mailman.42.1485203128.2473.python-list@python.org>
Message-ID: <cffild-vgj.ln1@oceanview.tundraware.com>

On 01/23/2017 02:19 PM, Chris Angelico wrote:
> On Tue, Jan 24, 2017 at 6:59 AM, Grant Edwards
> <grant.b.edwards at gmail.com> wrote:
>> On 2017-01-23, breamoreboy at gmail.com <breamoreboy at gmail.com> wrote:
>>
>>> The article is here http://lenkaspace.net/index.php/blog/show/111
>>
>> I don't really think any of his points are valid, but one way that
>> programming in Python is bad for you:
>>
>>  * It reduces your tolerance for progamming in PHP zero.  If you end
>>    up assigned to a PHP project, you end up miserable and unpleasant
>>    to work with or just plain unemployed.
> 
> I believe that's "bad for you" in the sense that chocolate is bad for you.
> 
> It isn't.
> 
> ChrisA
> 


It's bad for you in the same sense tha chocolate is bad for you - if you
melt it and pour it into your ears...


From bc at freeuk.com  Mon Jan 23 19:44:14 2017
From: bc at freeuk.com (BartC)
Date: Tue, 24 Jan 2017 00:44:14 +0000
Subject: How coding in Python is bad for you
In-Reply-To: <mailman.49.1485209394.2473.python-list@python.org>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
 <mailman.49.1485209394.2473.python-list@python.org>
Message-ID: <o667tr$evq$1@dont-email.me>

On 23/01/2017 22:09, Chris Angelico wrote:
> On Tue, Jan 24, 2017 at 8:55 AM, BartC <bc at freeuk.com> wrote:
>> On 23/01/2017 17:34, Chris Angelico wrote:
>>>
>>> On Tue, Jan 24, 2017 at 4:24 AM,  <breamoreboy at gmail.com> wrote:
>>>>
>>>> The article is here http://lenkaspace.net/index.php/blog/show/111
>>>
>>>
>>> I would respond point-by-point if I thought the author had a clue.
>>
>>
>> I thought points 1 to 4 were valid, in that the assertions were true.
>
> 1 is wrong - there is structure, same as in every language. Or if it's
> true, it's true in every language.

Python (I think in common with other scripting languages) allows you to 
place statement outside functions, either before, after or in-between 
functions. While functions themselves, as well as imports, can be 
conditionally defined.

  2 is also trivially true - you can
> ALWAYS define variables wrongly. Yes, okay, so you don't have data
> type checking, but that's only going to catch a specific subset of
> errors.

With Python, you can take function names that you've defined, imported 
modules, or math.pi, and set them all to "edward g robinson". (The name 
just came into my head..)

> 3, well, okay. But if you get your indentation wrong in C++,
> Java, etc, it should fail code review.

With C++ or Java, it's possible to tell the indentation is wrong 
(because of the extra redundancy of having the indentation /and/ block 
delimiters). That's a bit harder in Python making source more fragile.

> 4 is flat out wrong.

(About having no compiler.) Yes (C)Python does have a byte-code compiler 
but there are a vast range of errors that it cannot trap at compile-time 
because of its dynamic nature.

Maybe you can run tools to do extra analyses, but as it's normally used, 
many errors are not detected until execution. Spelling errors in names 
for example. (Actually when I tested my assertion above I assigned to 
math.p rather than math.pi; no error not even at runtime, just the wrong 
result. Or technically the right one, as math.pi still had the usual value!)

I'm not criticising it, just stating facts which may well have been the 
experience of the guy who wrote the article, giving the impression of a 
more chaotic, free-for-all language than they may have been used to, or 
expected.

-- 
bartc


From rosuav at gmail.com  Mon Jan 23 19:56:01 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Jan 2017 11:56:01 +1100
Subject: How coding in Python is bad for you
In-Reply-To: <o667tr$evq$1@dont-email.me>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
 <mailman.49.1485209394.2473.python-list@python.org>
 <o667tr$evq$1@dont-email.me>
Message-ID: <CAPTjJmqftxV-cqkFtpijeqq83CP+Yx+jp1km82VK_OpKUZaRSg@mail.gmail.com>

On Tue, Jan 24, 2017 at 11:44 AM, BartC <bc at freeuk.com> wrote:
> On 23/01/2017 22:09, Chris Angelico wrote:
>> 1 is wrong - there is structure, same as in every language. Or if it's
>> true, it's true in every language.
>
>
> Python (I think in common with other scripting languages) allows you to
> place statement outside functions, either before, after or in-between
> functions. While functions themselves, as well as imports, can be
> conditionally defined.

In other words, Python doesn't have arbitrary, useless structure by
forcing you to put everything inside a class definition and then
inside a method, as in Java. How is that a reason that Python is "bad
for you"?

REXX has even less structure than Python - it doesn't even have
functions, just labels, so you can actually have two functions that
share a common tail. And yes, you can abuse that horrendously to
create unreadable code. Is REXX a bad language because of that? No.
You can use structure badly, and you can use freedom badly.

>  2 is also trivially true - you can
>>
>> ALWAYS define variables wrongly. Yes, okay, so you don't have data
>> type checking, but that's only going to catch a specific subset of
>> errors.
>
>
> With Python, you can take function names that you've defined, imported
> modules, or math.pi, and set them all to "edward g robinson". (The name just
> came into my head..)

Yes, and? You can do that in other languages too. So? Again, how is
this proof that Python is "bad for you"?

>> 3, well, okay. But if you get your indentation wrong in C++,
>> Java, etc, it should fail code review.
>
>
> With C++ or Java, it's possible to tell the indentation is wrong (because of
> the extra redundancy of having the indentation /and/ block delimiters).
> That's a bit harder in Python making source more fragile.

With C++ or Java, it's possible to tell that the braces are misplaced
(because of the extra redundancy). When that happens, the compiler
won't tell you; it'll just silently do the wrong thing. In Python,
that can't happen. Python is therefore more robust.

What's to say which is correct?

>> 4 is flat out wrong.
>
>
> (About having no compiler.) Yes (C)Python does have a byte-code compiler but
> there are a vast range of errors that it cannot trap at compile-time because
> of its dynamic nature.
>
> Maybe you can run tools to do extra analyses, but as it's normally used,
> many errors are not detected until execution. Spelling errors in names for
> example. (Actually when I tested my assertion above I assigned to math.p
> rather than math.pi; no error not even at runtime, just the wrong result. Or
> technically the right one, as math.pi still had the usual value!)

Plenty of editors can catch those even before you run the code. And
there are languages with far more structure that still don't protect
you against very common classes of bug.

if (i = 1) {
    printf("i is 1.... now.");
}

Some compilers will give you a warning for this code, if you ask for
all warnings to be enabled. Others won't. The C language doesn't
protect you. Should we abolish C?

> I'm not criticising it, just stating facts which may well have been the
> experience of the guy who wrote the article, giving the impression of a more
> chaotic, free-for-all language than they may have been used to, or expected.

And because it's not what he's used to, it is a fundamentally bad
language. That's the sign of a badly uninformed post.

ChrisA


From rosuav at gmail.com  Mon Jan 23 19:58:38 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Jan 2017 11:58:38 +1100
Subject: How coding in Python is bad for you
In-Reply-To: <tc9d8cl0d0u9shu3gmii46jlmhgkpo49dl@4ax.com>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <o65nbu$mre$1@blaine.gmane.org>
 <CAPTjJmqh_jTGyZ0_v-JELxM--H=b-2azB3aSC5fSq1Hk38CpXQ@mail.gmail.com>
 <mailman.42.1485203128.2473.python-list@python.org>
 <RLthA.146356$c41.2628@fx40.am4>
 <slrno8cqj2.2ca.jon+usenet@sable.unequivocal.eu>
 <19df8402-c187-4250-b7f8-66d7e02475c0@googlegroups.com>
 <o661hk$nvk$1@dont-email.me> <tc9d8cl0d0u9shu3gmii46jlmhgkpo49dl@4ax.com>
Message-ID: <CAPTjJmp-k=evEuVO4KsUuifiFcKuCMLHycX20VtAYSGw3dwjaQ@mail.gmail.com>

On Tue, Jan 24, 2017 at 11:55 AM, Dennis Lee Bieber
<wlfraed at ix.netcom.com> wrote:
> On Mon, 23 Jan 2017 22:55:19 +0000, mm0fmf <none at invalid.com> declaimed the
> following:
>
>
>>50lbs of coffee beans made into espresso and 22lbs of chocolate to eat
>>with all those tiny cups.
>>
>         How about just 75lbs of chocolate covered espresso beans

Can you fire them out of a machine gun?

ChrisA


From bc at freeuk.com  Mon Jan 23 20:47:07 2017
From: bc at freeuk.com (BartC)
Date: Tue, 24 Jan 2017 01:47:07 +0000
Subject: How coding in Python is bad for you
In-Reply-To: <mailman.53.1485219364.2473.python-list@python.org>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
 <mailman.49.1485209394.2473.python-list@python.org>
 <o667tr$evq$1@dont-email.me>
 <CAPTjJmqftxV-cqkFtpijeqq83CP+Yx+jp1km82VK_OpKUZaRSg@mail.gmail.com>
 <mailman.53.1485219364.2473.python-list@python.org>
Message-ID: <o66bjo$oqb$1@dont-email.me>

On 24/01/2017 00:56, Chris Angelico wrote:
> On Tue, Jan 24, 2017 at 11:44 AM, BartC <bc at freeuk.com> wrote:

>> With C++ or Java, it's possible to tell the indentation is wrong (because of
>> the extra redundancy of having the indentation /and/ block delimiters).
>> That's a bit harder in Python making source more fragile.
>
> With C++ or Java, it's possible to tell that the braces are misplaced
> (because of the extra redundancy). When that happens, the compiler
> won't tell you; it'll just silently do the wrong thing. In Python,
> that can't happen. Python is therefore more robust.
>
> What's to say which is correct?

I don't get you. Start with this code

if 0:
     print ("one")
     print ("two")
print ("three")

It prints "three". Now the second indent accidentally gets deleted:

if 0:
     print ("one")
print ("two")
print ("three")

It still runs, but now prints "two", "three". Take the same code with 
block delimiters, and take out that same indent:

if 0 then
     print ("one")
print ("two")
endif
print ("three")

It still compiles, it still runs, and still shows the correct "three" as 
output. And the discrepancy can be caught by extra tools (that you say 
ought to be used), or it is obvious visually anyway that the "two" line 
belongs with the "one" line not the "three" line.

Yes, delimiters can be placed wrongly, but that is a harder error to 
make just by pressing one key (deleting a tab, or pressing Tab).

(Someone is now going to tell me that it is possible to declare:

   endif = 0

in Python, and use 'endif' at the end of a block just like my example. 
Now any adjacent line one tab out of place will be equally obvious. 
However, no one does that! The language needs to require it and enforce it.)

>> but as it's normally used,
>> many errors are not detected until execution.

> Plenty of editors can catch those even before you run the code.

Extra tools...

(But how would it catch assigning to a wrongly spelled attribute?)

-- 
Bartc


From steve+python at pearwood.info  Mon Jan 23 20:55:50 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Tue, 24 Jan 2017 12:55:50 +1100
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
Message-ID: <5886b429$0$1605$c3e8da3$5496439d@news.astraweb.com>

On Tue, 24 Jan 2017 08:55 am, BartC wrote:

> On 23/01/2017 17:34, Chris Angelico wrote:
>> On Tue, Jan 24, 2017 at 4:24 AM,  <breamoreboy at gmail.com> wrote:
>>> The article is here http://lenkaspace.net/index.php/blog/show/111
>>
>> I would respond point-by-point if I thought the author had a clue.
> 
> I thought points 1 to 4 were valid, in that the assertions were true.

Assertions can be true and still nonsense criticisms.

"Oh my gawd, this car goes forward AND backwards!!! What a pile of guano!"

What he's describing as flaws in language are seen by many as strengths of
the language. Not only can Python go forward and backward, it can turn
around corners as well!

The author seems to want a B&D language which will force him to do The Right
Thing? whether you want to or not. He seems to care about a very narrow
definition of correctness, and doesn't mind how many weeks or months it
takes him to write the code, or for that matter, how many years it takes
him to learn how to write the code in one of his preferred languages:

"...it takes years to build up a sense of what is good and what is bad
coding practise"

The reason why Python has become the #1 language for scientific computing is
that for most such programmings, the extra level of safety you (allegedly)
get from heavyweight C++ and Java style coding frameworks is unjustified.
You're not building a nuclear reactor. With Python, you can get reliable
*enough* code quickly, rather than bulletproof code that takes you forever.

Or I should say, *allegedly* bulletproof. There's no actual reliable,
objective evidence that coding in Java or C++ leads to actually more
reliable code, rather than just the false sense of security that because it
was *really really hard* to get the compiler to accept your code, it must
have been protecting you from all sorts of bad things. Maybe it was, maybe
it wasn't.



> Point 5 (memory leaks) I haven't experienced.

I suspect he's using memory leak in the sense, if you hold onto data
forever, the memory used by that data will never be available for re-use.

Reading his post, I get the impression he's the sort of programmer who
believes in never, ever, ever, ever re-using a variable, so he might do
something like:

raw_data = collect_raw_data()  # generates 10GB of data
data_after_step_one = massage(raw_data)
data_after_step_two = process(data_after_step_one)
...
sorted_data = sorted(data_after_step_ten)

and then wonders why he's running out of memory. "That's a memory leak!"

But perhaps not. Maybe he's just using a lot of badly written C extensions
that do leak memory. Or maybe he's one of the unlucky few who have stumbled
across genuine memory leaks in the interpreter, but hasn't bothered to
report it as a bug or upgrade to a version where it is fixed.

Or maybe he's just mistaken. Or lying.


> Point 6 (libraries depending on libraries...) is probably true in other
> languages too.

"I must have installed at least 30 libraries"

Really? 30? As many as that? You poor thing.


> Point 7 (Python claiming to be general purpose) I don't have an opinion
> about.

Python is an object-oriented language which encourages multi-paradigm coding
styles: OOP, functional and even procedural. The underlying data model is
based on objects, but that doesn't imply that you must or even should write
all your code in an OO style.

I suspect this guy is just a Java or C++ bigot.

I have nothing against those who like to program in Java or C++, that's
cool. I have my opinion on the languages themselves, but that's often a
matter of personal taste. But when somebody says:

"For example, encapsulation, one of the basic principles in OO is
non-existant in Python."

as he does, that's a form of the "no true Scotsman" fallacy. He is asserting
that *his* (probably taken from Java?) definition of encapsulation is the
only one. And that's why I call him a bigot. In a figurative sense -- the
author might be the sweetest, most open and unprejudiced guy in the world
when it comes to skin colour or religion for all I know.

https://en.wikipedia.org/wiki/Object-oriented_programming#Encapsulation




-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From rosuav at gmail.com  Mon Jan 23 21:38:46 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Jan 2017 13:38:46 +1100
Subject: How coding in Python is bad for you
In-Reply-To: <o66bjo$oqb$1@dont-email.me>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
 <mailman.49.1485209394.2473.python-list@python.org>
 <o667tr$evq$1@dont-email.me>
 <CAPTjJmqftxV-cqkFtpijeqq83CP+Yx+jp1km82VK_OpKUZaRSg@mail.gmail.com>
 <mailman.53.1485219364.2473.python-list@python.org>
 <o66bjo$oqb$1@dont-email.me>
Message-ID: <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>

On Tue, Jan 24, 2017 at 12:47 PM, BartC <bc at freeuk.com> wrote:
> On 24/01/2017 00:56, Chris Angelico wrote:
>>
>> On Tue, Jan 24, 2017 at 11:44 AM, BartC <bc at freeuk.com> wrote:
>
>
>>> With C++ or Java, it's possible to tell the indentation is wrong (because
>>> of
>>> the extra redundancy of having the indentation /and/ block delimiters).
>>> That's a bit harder in Python making source more fragile.
>>
>>
>> With C++ or Java, it's possible to tell that the braces are misplaced
>> (because of the extra redundancy). When that happens, the compiler
>> won't tell you; it'll just silently do the wrong thing. In Python,
>> that can't happen. Python is therefore more robust.
>>
>> What's to say which is correct?
>
> Take the same code with block
> delimiters, and take out that same indent:
>
> if 0 then
>     print ("one")
> print ("two")
> endif
> print ("three")
>
> It still compiles, it still runs, and still shows the correct "three" as
> output.

My point is that you *assume* that showing just "three" is the correct
behaviour. Why? Why do you automatically assume that the indentation
is wrong and the endif is correct? All you have is that the two
disagree.

That's the sort of (presumably unintentional) bias that comes from
your particular history of programming languages. Some languages teach
you that "foo" and "Foo" are the same name. Others teach you that the
integer 1 and the string "1" aren't materially different. Still others
leave you believing that bytes and characters are perfectly
equivalent. All those assumptions are proven wrong when you switch to
a language that isn't like that, and indentation is the same.

So what's to say which is more important? Surely it's nothing more
than your preconceived ideas, and could easily be different if you had
different experiences?

ChrisA


From rosuav at gmail.com  Mon Jan 23 21:41:39 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Jan 2017 13:41:39 +1100
Subject: How coding in Python is bad for you
In-Reply-To: <5886b429$0$1605$c3e8da3$5496439d@news.astraweb.com>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <5886b429$0$1605$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmq5qR8Mstx3ZJZ2EEkFvxJtb8XFKKF1GyBuEH=vL3ciUg@mail.gmail.com>

On Tue, Jan 24, 2017 at 12:55 PM, Steve D'Aprano
<steve+python at pearwood.info> wrote:
> Reading his post, I get the impression he's the sort of programmer who
> believes in never, ever, ever, ever re-using a variable, so he might do
> something like:
>
> raw_data = collect_raw_data()  # generates 10GB of data
> data_after_step_one = massage(raw_data)
> data_after_step_two = process(data_after_step_one)
> ...
> sorted_data = sorted(data_after_step_ten)
>
> and then wonders why he's running out of memory. "That's a memory leak!"

How is that any different in any other language? I don't understand
how even this is a criticism of Python. If you were working in Java,
say, you'd have basically the same result - keep all the stuff, keep
all the memory usage.

ChrisA


From steve+comp.lang.python at pearwood.info  Mon Jan 23 23:22:11 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Tue, 24 Jan 2017 15:22:11 +1100
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
 <mailman.49.1485209394.2473.python-list@python.org>
 <o667tr$evq$1@dont-email.me>
 <CAPTjJmqftxV-cqkFtpijeqq83CP+Yx+jp1km82VK_OpKUZaRSg@mail.gmail.com>
 <mailman.53.1485219364.2473.python-list@python.org>
 <o66bjo$oqb$1@dont-email.me>
 <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>
 <mailman.55.1485225529.2473.python-list@python.org>
Message-ID: <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>

On Tuesday 24 January 2017 13:38, Chris Angelico wrote:

> On Tue, Jan 24, 2017 at 12:47 PM, BartC <bc at freeuk.com> wrote:

>> Take the same code with block
>> delimiters, and take out that same indent:
>>
>> if 0 then
>>     print ("one")
>> print ("two")
>> endif
>> print ("three")
>>
>> It still compiles, it still runs, and still shows the correct "three" as
>> output.
> 
> My point is that you *assume* that showing just "three" is the correct
> behaviour. Why? Why do you automatically assume that the indentation
> is wrong and the endif is correct? All you have is that the two
> disagree.

It's Bart's special language, so the correct behaviour is whatever he says it 
is :-)

But more seriously, it's easy to typo an extra indent. It's harder to typo 
"endif" when you actually meant to type, oh, "ending = 1 if condition else 3", 
say. So faced with ambiguity, and the insistence that the right way to break 
ambiguity is to guess ("Do What I Mean, dammit!!!") the most likely guess is 
that the indentation is wrong.

But not guaranteed. That's the thing about being ambiguous -- there is a chance 
that the indentation is correct.

This *especially* applies to languages like C, when open/close delimiters 
optional if the block is only a single statement, and where the delimiters are 
only a single character.

And sure enough, C is prone to indent/brace mismatch errors.

When I design my killer language, it won't fail when there's a mismatch between 
indentation and open/close delimiters. Nor will it just give priority to one or 
the other. Instead, it will learn from your errors and typos in order to 
determine which you are statistically more likely to want, and silently compile 
the code that way. But without changing the source code, of course.



-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From steve+comp.lang.python at pearwood.info  Mon Jan 23 23:27:02 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Tue, 24 Jan 2017 15:27:02 +1100
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <5886b429$0$1605$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmq5qR8Mstx3ZJZ2EEkFvxJtb8XFKKF1GyBuEH=vL3ciUg@mail.gmail.com>
 <mailman.56.1485225702.2473.python-list@python.org>
Message-ID: <5886d797$0$1501$c3e8da3$5496439d@news.astraweb.com>

On Tuesday 24 January 2017 13:41, Chris Angelico wrote:

> On Tue, Jan 24, 2017 at 12:55 PM, Steve D'Aprano
> <steve+python at pearwood.info> wrote:
>> Reading his post, I get the impression he's the sort of programmer who
>> believes in never, ever, ever, ever re-using a variable, so he might do
>> something like:
>>
>> raw_data = collect_raw_data()  # generates 10GB of data
>> data_after_step_one = massage(raw_data)
>> data_after_step_two = process(data_after_step_one)
>> ...
>> sorted_data = sorted(data_after_step_ten)
>>
>> and then wonders why he's running out of memory. "That's a memory leak!"
> 
> How is that any different in any other language? I don't understand
> how even this is a criticism of Python. If you were working in Java,
> say, you'd have basically the same result - keep all the stuff, keep
> all the memory usage.

Keep in mind that I'm only *guessing* from the impression that the author 
gives. I don't *know* that is what he's doing.

He makes all these claims about Python, but doesn't show his code, so the best 
we can do is try to predict what could plausibly explain the observation.



-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From greg.ewing at canterbury.ac.nz  Mon Jan 23 23:31:57 2017
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Tue, 24 Jan 2017 17:31:57 +1300
Subject: How coding in Python is bad for you
In-Reply-To: <mailman.54.1485219521.2473.python-list@python.org>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <o65nbu$mre$1@blaine.gmane.org>
 <CAPTjJmqh_jTGyZ0_v-JELxM--H=b-2azB3aSC5fSq1Hk38CpXQ@mail.gmail.com>
 <mailman.42.1485203128.2473.python-list@python.org>
 <RLthA.146356$c41.2628@fx40.am4>
 <slrno8cqj2.2ca.jon+usenet@sable.unequivocal.eu>
 <19df8402-c187-4250-b7f8-66d7e02475c0@googlegroups.com>
 <o661hk$nvk$1@dont-email.me> <tc9d8cl0d0u9shu3gmii46jlmhgkpo49dl@4ax.com>
 <CAPTjJmp-k=evEuVO4KsUuifiFcKuCMLHycX20VtAYSGw3dwjaQ@mail.gmail.com>
 <mailman.54.1485219521.2473.python-list@python.org>
Message-ID: <eeo3lvFd6p7U1@mid.individual.net>

Chris Angelico wrote:
> On Tue, Jan 24, 2017 at 11:55 AM, Dennis Lee Bieber
> <wlfraed at ix.netcom.com> wrote:
> 
>>On Mon, 23 Jan 2017 22:55:19 +0000, mm0fmf <none at invalid.com> declaimed the
>>following:
>>
>>>50lbs of coffee beans made into espresso and 22lbs of chocolate to eat
>>>with all those tiny cups.
>>
>>        How about just 75lbs of chocolate covered espresso beans
> 
> Can you fire them out of a machine gun?

And if you can, should you use a Bren or a Spandau?

(Sorry, I've been watching too many lindybeige videos about
machine guns recently. Just throw a pommel at me.)

-- 
Greg


From rosuav at gmail.com  Mon Jan 23 23:41:30 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Jan 2017 15:41:30 +1100
Subject: How coding in Python is bad for you
In-Reply-To: <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
 <mailman.49.1485209394.2473.python-list@python.org>
 <o667tr$evq$1@dont-email.me>
 <CAPTjJmqftxV-cqkFtpijeqq83CP+Yx+jp1km82VK_OpKUZaRSg@mail.gmail.com>
 <mailman.53.1485219364.2473.python-list@python.org>
 <o66bjo$oqb$1@dont-email.me>
 <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>
 <mailman.55.1485225529.2473.python-list@python.org>
 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmqupVWHHjnRHTPqxYmVjrtS_k7PdJY0JR_J3KjQTV1uXw@mail.gmail.com>

On Tue, Jan 24, 2017 at 3:22 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> But more seriously, it's easy to typo an extra indent. It's harder to typo
> "endif" when you actually meant to type, oh, "ending = 1 if condition else 3",
> say. So faced with ambiguity, and the insistence that the right way to break
> ambiguity is to guess ("Do What I Mean, dammit!!!") the most likely guess is
> that the indentation is wrong.
>
> But not guaranteed. That's the thing about being ambiguous -- there is a chance
> that the indentation is correct.

Indeed. I teach JavaScript as well as Python, and I've seen some
pretty horrendous indentation flaws (examples available if people ask
privately, but I will anonymize them because I'm not here to shame
students) - but there have been nearly as many cases where the
indentation's fine and the bracket nesting isn't. I probably sound
like a broken record [1] with the number of times I've said "check
your indentation", as a hint to where the missed-out close brace or
parenthesis is. True, with "endif" it's a bit harder to typo, but it's
still just as easy to make a copy-and-paste error and end up with code
like this:

if condition:
    statement
endif
    statement
endif

What's this code meant to do? Can't know.

Remember: If you have only one clock, it might be right and it might
be wrong, but it's consistent. If you have two clocks and they
disagree, you have no clue what the time is.

ChrisA

[1] Wonder how many of today's generation of programmers have actually
heard a record skip...


From steve+comp.lang.python at pearwood.info  Tue Jan 24 00:00:30 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Tue, 24 Jan 2017 16:00:30 +1100
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
 <mailman.49.1485209394.2473.python-list@python.org>
 <o667tr$evq$1@dont-email.me>
 <CAPTjJmqftxV-cqkFtpijeqq83CP+Yx+jp1km82VK_OpKUZaRSg@mail.gmail.com>
 <mailman.53.1485219364.2473.python-list@python.org>
 <o66bjo$oqb$1@dont-email.me>
 <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>
 <mailman.55.1485225529.2473.python-list@python.org>
 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqupVWHHjnRHTPqxYmVjrtS_k7PdJY0JR_J3KjQTV1uXw@mail.gmail.com>
 <mailman.57.1485232893.2473.python-list@python.org>
Message-ID: <5886df70$0$11127$c3e8da3@news.astraweb.com>

On Tuesday 24 January 2017 15:41, Chris Angelico wrote:

> Remember: If you have only one clock, it might be right and it might
> be wrong, but it's consistent. If you have two clocks and they
> disagree, you have no clue what the time is.

During the golden age of sail, there was a saying, never go to sea with two 
chronometers. Take one, or three, but never two.

Obviously the lesson here is that programming languages should have *three* 
ways of setting out the structure:

    if condition:
        {
          BEGIN
            code goes here
          }
        END


> [1] Wonder how many of today's generation of programmers have actually
> heard a record skip...

Haven't you heard? Vinyl is making a comeback. Seriously.


-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From rosuav at gmail.com  Tue Jan 24 00:16:43 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Jan 2017 16:16:43 +1100
Subject: How coding in Python is bad for you
In-Reply-To: <5886df70$0$11127$c3e8da3@news.astraweb.com>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
 <mailman.49.1485209394.2473.python-list@python.org>
 <o667tr$evq$1@dont-email.me>
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Message-ID: <CAPTjJmquAedGj+3k7OwMEVeWqB5z_dyq7CkUWdkX6bb=XYXYSg@mail.gmail.com>

On Tue, Jan 24, 2017 at 4:00 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> On Tuesday 24 January 2017 15:41, Chris Angelico wrote:
>
>> Remember: If you have only one clock, it might be right and it might
>> be wrong, but it's consistent. If you have two clocks and they
>> disagree, you have no clue what the time is.
>
> During the golden age of sail, there was a saying, never go to sea with two
> chronometers. Take one, or three, but never two.
>
> Obviously the lesson here is that programming languages should have *three*
> ways of setting out the structure:
>
>     if condition:
>         {
>           BEGIN
>             code goes here
>           }
>         END
>

No no no. You have two orthogonal styles (indentation and tokens), but
then you added another of the same style (another pair of tokens). You
need a third orthogonal style. I suggest that each nesting level be
heralded by an increase in indentation, an open brace, and a new text
colour.

ChrisA


From bob.martin at excite.com  Tue Jan 24 02:00:06 2017
From: bob.martin at excite.com (Bob Martin)
Date: Tue, 24 Jan 2017 07:00:06 GMT
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <mailman.53.1485219364.2473.python-list@python.org>
Message-ID: <eeocbmFepsqU1@mid.individual.net>

in 770207 20170124 005601 Chris Angelico <rosuav at gmail.com> wrote:

>REXX has even less structure than Python - it doesn't even have
>functions, just labels, so you can actually have two functions that
>share a common tail. And yes, you can abuse that horrendously to
>create unreadable code. Is REXX a bad language because of that? No.
>You can use structure badly, and you can use freedom badly.

Of course Rexx has functions!


From rosuav at gmail.com  Tue Jan 24 02:08:53 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Jan 2017 18:08:53 +1100
Subject: How coding in Python is bad for you
In-Reply-To: <eeocbmFepsqU1@mid.individual.net>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <mailman.53.1485219364.2473.python-list@python.org>
 <eeocbmFepsqU1@mid.individual.net>
Message-ID: <CAPTjJmqt7-Ja+JHg=N_QJBgFwT_adV7PcjReSJFw4+QSL2Ki-w@mail.gmail.com>

On Tue, Jan 24, 2017 at 6:00 PM, Bob Martin <bob.martin at excite.com> wrote:
> in 770207 20170124 005601 Chris Angelico <rosuav at gmail.com> wrote:
>
>>REXX has even less structure than Python - it doesn't even have
>>functions, just labels, so you can actually have two functions that
>>share a common tail. And yes, you can abuse that horrendously to
>>create unreadable code. Is REXX a bad language because of that? No.
>>You can use structure badly, and you can use freedom badly.
>
> Of course Rexx has functions!

Built-ins, yes, but when you define your own, it's by giving a label.
It isn't a function until it's called as a function.

ChrisA


From rryan.asu at gmail.com  Tue Jan 24 02:09:09 2017
From: rryan.asu at gmail.com (rryan.asu at gmail.com)
Date: Mon, 23 Jan 2017 23:09:09 -0800 (PST)
Subject: PhotoImage.paste
Message-ID: <d0476502-d414-4022-81e6-b28a648ac3ca@googlegroups.com>

I'm trying to build a tkinter GUI with python 3.5, and would like to interactively adjust the color palette for an image by moving the mouse in the canvas using PIL.  In pseudo-code, I have something like

palette=color_map(x,y)   # x,y are scalars indicating the position of the mouse in the Canvas
image.putpalette(palette)
photo.paste(image)

This works just fine, but is very slow.  The photo.paste(image) step takes about 0.15 s (using an image that is 4k x 4k).  I read the manual on effbot, and they caution that the paste method would be slow if the image is display --- and I'm guessing that's what I'm doing.  So my question is, what alternatives do I have to speed that step up.  

Thank you for any thoughts you might have...
-Russell



From auriocus at gmx.de  Tue Jan 24 02:46:06 2017
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Tue, 24 Jan 2017 08:46:06 +0100
Subject: How coding in Python is bad for you
In-Reply-To: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
Message-ID: <o670kq$2r2$1@dont-email.me>

Am 23.01.17 um 18:24 schrieb breamoreboy at gmail.com:
> The article is here http://lenkaspace.net/index.php/blog/show/111
>

I don't agree with it (unsurprisingly), even though Python is not my 
favourite language in itself, but a viable compromise for many 
circumstances. Below is a point-by-point reply.

(BTW, Lenka Pitonakova is a lady of Slova origin, so we should refer to 
her as "she")

1. Having the code in shoehorned into a given structure is no guarantee 
for clean code. Look at messy Java inheritance diagrams with hundreds of 
Factory objects all creating themselves around the code that solves the 
real problem

2. It is true that the prototype of a function can be more descriptive, 
if it includes type information (such as "list", "dict" etc.). See 
https://www.python.org/dev/peps/pep-0484/ The documentation is needed in 
any case to understand, what the function does. Mandatory types do not 
prevent bad naming of the arguments.

3. Significant indentation has been discussed over and over, with no 
clear result. Humans need indentation to identify structure in a large 
chunk of code. Brace language programmers use auto-indenters to do that, 
Python uses the layout to deduce the code blocks. Both can fail; most 
notably, missing braces in if clauses lead to several security bugs in 
the past, while white space can be messed up more easily. So that's a 
standoff.

4. It's true that a strict compiler can find errors earlier. Most 
notably, Haskell detects many errors during compile time. Linters exist 
for that purpose in interpreted languages. Still no compiler can 
actually catch semantic errors, which means that automated tests are 
needed anyway.

5. This is wrong. Python does have a garbage collector, but it uses 
reference counting (CPython) - so in simple cases you know exactly how 
to release the memory held by big objects. Unless you use a flawed library.

6. There are even more bad libraries for C and Java. Writing interfaces 
to libraries that do not fit together is actually a much greater pain in 
these languages.

7. This is actually the same argument as 6. Bad programmers wrote some 
code, which you want to use. That is independent of the language, maybe 
in a more strict language the author wouldn't bother to give you the 
code at all! Scientific software was always horrible, previously people 
used impenetrable FORTRAN 77, thankfully they use Python now. Lack of 
encapsulation is a featurenot a bug.

	Christian


From dieter at handshake.de  Tue Jan 24 04:59:20 2017
From: dieter at handshake.de (dieter)
Date: Tue, 24 Jan 2017 10:59:20 +0100
Subject: Is it possible to get the Physical memory address of a variable
 in python?
References: <CA+PdqeX4FsZGTmywOF-noZ8RNtEafj6HoTsKoMHCyHJ5zuUokg@mail.gmail.com>
Message-ID: <877f5ksrrb.fsf@handshake.de>

Sourabh Kalal <kalalsunnyy at gmail.com> writes:

> how we can access the value from using id..
> like x=10
> id(x)
> 3235346364
>
> how i can read value 10 using id 3235346364

You should not do this (read the value instead by looking at "x") --
unless you are debugging at "C" level. For "C" level debugging,
there is a set of "gdb" macros allowing you to display Python
objects giving their "C" level address.



From bc at freeuk.com  Tue Jan 24 06:52:51 2017
From: bc at freeuk.com (BartC)
Date: Tue, 24 Jan 2017 11:52:51 +0000
Subject: How coding in Python is bad for you
In-Reply-To: <mailman.57.1485232893.2473.python-list@python.org>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
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 <o65u0i$b4c$1@dont-email.me>
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Message-ID: <o67f3g$g50$1@dont-email.me>

On 24/01/2017 04:41, Chris Angelico wrote:
> On Tue, Jan 24, 2017 at 3:22 PM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> But more seriously, it's easy to typo an extra indent. It's harder to typo
>> "endif" when you actually meant to type, oh, "ending = 1 if condition else 3",
>> say. So faced with ambiguity, and the insistence that the right way to break
>> ambiguity is to guess ("Do What I Mean, dammit!!!") the most likely guess is
>> that the indentation is wrong.
>>
>> But not guaranteed. That's the thing about being ambiguous -- there is a chance
>> that the indentation is correct.
>
> Indeed. I teach JavaScript as well as Python, and I've seen some
> pretty horrendous indentation flaws (examples available if people ask
> privately, but I will anonymize them because I'm not here to shame
> students) - but there have been nearly as many cases where the
> indentation's fine and the bracket nesting isn't. I probably sound
> like a broken record [1] with the number of times I've said "check
> your indentation", as a hint to where the missed-out close brace or
> parenthesis is. True, with "endif" it's a bit harder to typo, but it's
> still just as easy to make a copy-and-paste error and end up with code
> like this:
>
> if condition:
>     statement
> endif
>     statement
> endif
>
> What's this code meant to do? Can't know.

But whatever it does, a language that enforces 'endif' would report an 
error, so requiring further investigation. Without the 'endifs', it 
would look like this:

  if condition:
      statement
      statement

Legal python.

Presumably you don't like parentheses in function calls for the same 
reasons; you'd prefer 'f a,b,c' rather than 'f(a,b,c)' in case, with 
copy&paste, someone might end up with: 'f(a,b,c),d)'.

Having 'f a,b,c,d' is better; much less chance of those pesky syntax errors!

> Remember: If you have only one clock, it might be right and it might
> be wrong, but it's consistent. If you have two clocks and they
> disagree, you have no clue what the time is.

I've actually got three wall clocks. Usually only one will disagree with 
the other two, meaning it needs a new battery. But don't they use such 
systems in avionics?

-- 
Bartc


From rosuav at gmail.com  Tue Jan 24 06:58:55 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Jan 2017 22:58:55 +1100
Subject: How coding in Python is bad for you
In-Reply-To: <o67f3g$g50$1@dont-email.me>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
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 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
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Message-ID: <CAPTjJmpaza4oVD54bbOVPwKC0Mxf4freW=F8gYvOtQL=YAZucQ@mail.gmail.com>

On Tue, Jan 24, 2017 at 10:52 PM, BartC <bc at freeuk.com> wrote:
>> Remember: If you have only one clock, it might be right and it might
>> be wrong, but it's consistent. If you have two clocks and they
>> disagree, you have no clue what the time is.
>
>
> I've actually got three wall clocks. Usually only one will disagree with the
> other two, meaning it needs a new battery. But don't they use such systems
> in avionics?

See what Steve said about 1 or 3 but never 2. Triple redundancy gives
you a chance to figure out that two of them agree.

ChrisA


From bc at freeuk.com  Tue Jan 24 07:12:05 2017
From: bc at freeuk.com (BartC)
Date: Tue, 24 Jan 2017 12:12:05 +0000
Subject: How coding in Python is bad for you
In-Reply-To: <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
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 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <o67g7i$k8c$1@dont-email.me>

On 24/01/2017 04:22, Steven D'Aprano wrote:
> On Tuesday 24 January 2017 13:38, Chris Angelico wrote:
>> On Tue, Jan 24, 2017 at 12:47 PM, BartC <bc at freeuk.com> wrote:

>>> if 0 then
>>>     print ("one")
>>> print ("two")
>>> endif

>> My point is that you *assume* that showing just "three" is the correct
>> behaviour. Why? Why do you automatically assume that the indentation
>> is wrong and the endif is correct? All you have is that the two
>> disagree.
>
> It's Bart's special language, so the correct behaviour is whatever he says it
> is :-)

I chose 'if...endif' above because it's used in a number of well-known 
languages. (Including PHP I think, while others use 'end if' or just 
'end'. In my own language I prefer 'if...fi')


> This *especially* applies to languages like C, when open/close delimiters
> optional if the block is only a single statement, and where the delimiters are
> only a single character.
>
> And sure enough, C is prone to indent/brace mismatch errors.

I didn't use brace syntax in the example for that reason. C has plenty 
of its own problems. Although funnily enough, its preprocessor language 
uses '#if...#endif'; much more sensible!

C suffers also from the 'dangling else' problem, which a 'if...endif' 
syntax doesn't.

Nor does Python's scheme, as the 'else' /has/ to be aligned with the 
corresponding 'if' or 'elif'. However... take this code:

   if a:
       b
       if c:
           d

You want to import an 'else' block from elsewhere to add to that nested if:

   if a:
       b
       if c:
           d
   else:
       e

The trouble is, that other code was not nested; it will need extra 
indentation here. Until that happens however, the above is still legal.

-- 
Bartc



From bc at freeuk.com  Tue Jan 24 07:19:16 2017
From: bc at freeuk.com (BartC)
Date: Tue, 24 Jan 2017 12:19:16 +0000
Subject: How coding in Python is bad for you
In-Reply-To: <mailman.61.1485259143.2473.python-list@python.org>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
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 <mailman.61.1485259143.2473.python-list@python.org>
Message-ID: <o67gl2$ll2$1@dont-email.me>

On 24/01/2017 11:58, Chris Angelico wrote:
> On Tue, Jan 24, 2017 at 10:52 PM, BartC <bc at freeuk.com> wrote:
>>> Remember: If you have only one clock, it might be right and it might
>>> be wrong, but it's consistent. If you have two clocks and they
>>> disagree, you have no clue what the time is.
>>
>>
>> I've actually got three wall clocks. Usually only one will disagree with the
>> other two, meaning it needs a new battery. But don't they use such systems
>> in avionics?
>
> See what Steve said about 1 or 3 but never 2. Triple redundancy gives
> you a chance to figure out that two of them agree.

But even with two clocks you will know something is amiss if they don't 
agree, and will seek confirmation from a third. With one clock you can't 
be sure, and could end up missing your flight or whatever.

(Of course, when the clocks go forward in the spring, all the (cheap, 
non-automatic) clocks in my house will show the same incorrect time!)

-- 
Bartc





From skip.montanaro at gmail.com  Tue Jan 24 07:20:43 2017
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Tue, 24 Jan 2017 06:20:43 -0600
Subject: How coding in Python is bad for you
In-Reply-To: <o67g7i$k8c$1@dont-email.me>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
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 <o667tr$evq$1@dont-email.me>
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 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <o67g7i$k8c$1@dont-email.me>
Message-ID: <CANc-5UzWnB4Rm5y0EKUDCLCuzektk1qc1GyvJvUmuC-6M6CLVw@mail.gmail.com>

I have nothing to add to the discussion other than too note that Gmail
marks many of the messages as spam. :-)

Skip


From python at mrabarnett.plus.com  Tue Jan 24 08:03:24 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Tue, 24 Jan 2017 13:03:24 +0000
Subject: How coding in Python is bad for you
In-Reply-To: <o67g7i$k8c$1@dont-email.me>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
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 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <o67g7i$k8c$1@dont-email.me>
Message-ID: <36cce4ec-46bf-6816-0f16-02b28309f69f@mrabarnett.plus.com>

On 2017-01-24 12:12, BartC wrote:
> On 24/01/2017 04:22, Steven D'Aprano wrote:
>> On Tuesday 24 January 2017 13:38, Chris Angelico wrote:
>>> On Tue, Jan 24, 2017 at 12:47 PM, BartC <bc at freeuk.com> wrote:
>
>>>> if 0 then
>>>>     print ("one")
>>>> print ("two")
>>>> endif
>
>>> My point is that you *assume* that showing just "three" is the correct
>>> behaviour. Why? Why do you automatically assume that the indentation
>>> is wrong and the endif is correct? All you have is that the two
>>> disagree.
>>
>> It's Bart's special language, so the correct behaviour is whatever he says it
>> is :-)
>
> I chose 'if...endif' above because it's used in a number of well-known
> languages. (Including PHP I think, while others use 'end if' or just
> 'end'. In my own language I prefer 'if...fi')
>
[snip]

PHP lets you use if...endif or braces.



From python at mrabarnett.plus.com  Tue Jan 24 08:08:34 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Tue, 24 Jan 2017 13:08:34 +0000
Subject: PhotoImage.paste
In-Reply-To: <d0476502-d414-4022-81e6-b28a648ac3ca@googlegroups.com>
References: <d0476502-d414-4022-81e6-b28a648ac3ca@googlegroups.com>
Message-ID: <2c6196b4-89ac-6111-cb13-5062bf538297@mrabarnett.plus.com>

On 2017-01-24 07:09, rryan.asu at gmail.com wrote:
> I'm trying to build a tkinter GUI with python 3.5, and would like to interactively adjust the color palette for an image by moving the mouse in the canvas using PIL.  In pseudo-code, I have something like
>
> palette=color_map(x,y)   # x,y are scalars indicating the position of the mouse in the Canvas
> image.putpalette(palette)
> photo.paste(image)
>
> This works just fine, but is very slow.  The photo.paste(image) step takes about 0.15 s (using an image that is 4k x 4k).  I read the manual on effbot, and they caution that the paste method would be slow if the image is display --- and I'm guessing that's what I'm doing.  So my question is, what alternatives do I have to speed that step up.
>
> Thank you for any thoughts you might have...
> -Russell
>
How often are you pasting?

Are you pasting whenever the mouse moves, even a little?

If that's the case, try using the .after method to paste only 
occasionally, and then only if the mouse has moved since the last time.



From alister.ware at ntlworld.com  Tue Jan 24 08:47:50 2017
From: alister.ware at ntlworld.com (alister)
Date: Tue, 24 Jan 2017 13:47:50 GMT
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <o65nbu$mre$1@blaine.gmane.org>
 <CAPTjJmqh_jTGyZ0_v-JELxM--H=b-2azB3aSC5fSq1Hk38CpXQ@mail.gmail.com>
 <mailman.42.1485203128.2473.python-list@python.org>
 <RLthA.146356$c41.2628@fx40.am4>
 <slrno8cqj2.2ca.jon+usenet@sable.unequivocal.eu>
 <19df8402-c187-4250-b7f8-66d7e02475c0@googlegroups.com>
 <CAPTjJmrz7L=OXAY9+t+yXs-XDu5C9QsR8cJVrbU8O86TsA8J9w@mail.gmail.com>
 <mailman.47.1485205865.2473.python-list@python.org>
Message-ID: <aWIhA.371506$1y4.160550@fx20.am4>

On Tue, 24 Jan 2017 08:11:02 +1100, Chris Angelico wrote:

> On Tue, Jan 24, 2017 at 8:04 AM, Adam M <amorawski at magna-power.com>
> wrote:
>> On Monday, January 23, 2017 at 3:41:17 PM UTC-5, Jon Ribbens wrote:
>>> On 2017-01-23, alister <ali....re at ntlworld.com> wrote:
>>> > On Tue, 24 Jan 2017 07:19:42 +1100, Chris Angelico wrote:
>>> >> I believe that's "bad for you" in the sense that chocolate is bad
>>> >> for you.
>>> >>
>>> >> It isn't.
>>> >
>>> > chocolate is a poison (lethal dose for a human approx 22lb)
>>>
>>> That's a meaningless statement. *Everything* is a poison in sufficient
>>> quantities.
>>
>> I think you need to calibrate your sarcasm filter ;-). By the way
>> coffee  is also dangerous - especially in 50lbs bags (when it hits
>> you).
> 
> Or with sufficient velocity. The LD50 of lead is about 450mg/kg [1],
> which means that a typical 70kg human could ingest about 31 grams of
> lead and have a fifty-fifty chance of survival. But just a few grams of
> lead at the speed of sound will probably kill you. [2]

if you were to take the statistics of WWI or WWII (And probably any other 
major war & compare the number of rounds fired to the number of people 
killed by gunshot then you could say it probably wouldn't ;-)
(No I am not willing to put this to the test)

> 
> ChrisA
> 
> [1] http://whs.rocklinusd.org/documents/Science/Lethal_Dose_Table.pdf
> [2] https://xkcd.com/444/





-- 
Given a choice between grief and nothing, I'd choose grief.
		-- William Faulkner


From alister.ware at ntlworld.com  Tue Jan 24 09:26:03 2017
From: alister.ware at ntlworld.com (alister)
Date: Tue, 24 Jan 2017 14:26:03 GMT
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <o65nbu$mre$1@blaine.gmane.org>
 <CAPTjJmqh_jTGyZ0_v-JELxM--H=b-2azB3aSC5fSq1Hk38CpXQ@mail.gmail.com>
 <mailman.42.1485203128.2473.python-list@python.org>
 <RLthA.146356$c41.2628@fx40.am4>
 <slrno8cqj2.2ca.jon+usenet@sable.unequivocal.eu>
Message-ID: <%tJhA.371507$1y4.144483@fx20.am4>

On Mon, 23 Jan 2017 20:39:26 +0000, Jon Ribbens wrote:

> On 2017-01-23, alister <alister.ware at ntlworld.com> wrote:
>> On Tue, 24 Jan 2017 07:19:42 +1100, Chris Angelico wrote:
>>> I believe that's "bad for you" in the sense that chocolate is bad for
>>> you.
>>> 
>>> It isn't.
>>
>> chocolate is a poison (lethal dose for a human approx 22lb)
> 
> That's a meaningless statement. *Everything* is a poison in sufficient
> quantities.

indees when I here someone saying "I won't have any xyz because they have 
heard that too much is bad for them" I invariably inform them that too 
much oxygen is poisonous & challenge then to cut that out completely :-)
.



-- 
Peace is much more precious than a piece of land... let there be no more 
wars.
		-- Mohammed Anwar Sadat, 1918-1981


From jon+usenet at unequivocal.eu  Tue Jan 24 09:28:55 2017
From: jon+usenet at unequivocal.eu (Jon Ribbens)
Date: Tue, 24 Jan 2017 14:28:55 -0000 (UTC)
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <o65nbu$mre$1@blaine.gmane.org>
 <CAPTjJmqh_jTGyZ0_v-JELxM--H=b-2azB3aSC5fSq1Hk38CpXQ@mail.gmail.com>
 <mailman.42.1485203128.2473.python-list@python.org>
 <RLthA.146356$c41.2628@fx40.am4>
 <slrno8cqj2.2ca.jon+usenet@sable.unequivocal.eu>
 <%tJhA.371507$1y4.144483@fx20.am4>
Message-ID: <slrno8ep8b.3j6.jon+usenet@sable.unequivocal.eu>

On 2017-01-24, alister <alister.ware at ntlworld.com> wrote:
> On Mon, 23 Jan 2017 20:39:26 +0000, Jon Ribbens wrote:
>> That's a meaningless statement. *Everything* is a poison in sufficient
>> quantities.
>
> indees when I here someone saying "I won't have any xyz because they have 
> heard that too much is bad for them" I invariably inform them that too 
> much oxygen is poisonous & challenge then to cut that out completely :-)

Just wait until they find out that raw fruit and vegetables contain
hundreds of chemicals!


From rryan.asu at gmail.com  Tue Jan 24 10:15:22 2017
From: rryan.asu at gmail.com (rryan.asu at gmail.com)
Date: Tue, 24 Jan 2017 07:15:22 -0800 (PST)
Subject: PhotoImage.paste
In-Reply-To: <mailman.64.1485263317.2473.python-list@python.org>
References: <d0476502-d414-4022-81e6-b28a648ac3ca@googlegroups.com>
 <2c6196b4-89ac-6111-cb13-5062bf538297@mrabarnett.plus.com>
 <mailman.64.1485263317.2473.python-list@python.org>
Message-ID: <e6f3f915-9bbe-41cf-8594-4a2e6dee9550@googlegroups.com>

Hi MRAB

Yes, I am pasting every time the mouse moves (or every time the tk event handler gets called).  I thought about the after method, and I guess i can try to implement that.  It seems like that would help in the "jerkiness" of the GUI's response, but it leaves me kinda disappointed.  I obviously do not understand the inner workings of PIL or tk, but it seems kinda broken that it must take 0.2 sec to adjust a palette.  This GUI is a rewrite of a code I had in another language, and this palette modifying was much faster.  

I'll try the after method, hoping it'll at least make the GUI a bit more responsive.  

Thanks again!
Russell


On Tuesday, January 24, 2017 at 8:08:53 AM UTC-5, MRAB wrote:
> On 2017-01-24 07:09, at gmail.com wrote:
> > I'm trying to build a tkinter GUI with python 3.5, and would like to interactively adjust the color palette for an image by moving the mouse in the canvas using PIL.  In pseudo-code, I have something like
> >
> > palette=color_map(x,y)   # x,y are scalars indicating the position of the mouse in the Canvas
> > image.putpalette(palette)
> > photo.paste(image)
> >
> > This works just fine, but is very slow.  The photo.paste(image) step takes about 0.15 s (using an image that is 4k x 4k).  I read the manual on effbot, and they caution that the paste method would be slow if the image is display --- and I'm guessing that's what I'm doing.  So my question is, what alternatives do I have to speed that step up.
> >
> > Thank you for any thoughts you might have...
> > -Russell
> >
> How often are you pasting?
> 
> Are you pasting whenever the mouse moves, even a little?
> 
> If that's the case, try using the .after method to paste only 
> occasionally, and then only if the mouse has moved since the last time.


From ben.usenet at bsb.me.uk  Tue Jan 24 10:51:57 2017
From: ben.usenet at bsb.me.uk (Ben Bacarisse)
Date: Tue, 24 Jan 2017 15:51:57 +0000
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
 <mailman.49.1485209394.2473.python-list@python.org>
 <o667tr$evq$1@dont-email.me>
 <CAPTjJmqftxV-cqkFtpijeqq83CP+Yx+jp1km82VK_OpKUZaRSg@mail.gmail.com>
 <mailman.53.1485219364.2473.python-list@python.org>
 <o66bjo$oqb$1@dont-email.me>
 <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>
 <mailman.55.1485225529.2473.python-list@python.org>
 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqupVWHHjnRHTPqxYmVjrtS_k7PdJY0JR_J3KjQTV1uXw@mail.gmail.com>
 <mailman.57.1485232893.2473.python-list@python.org>
Message-ID: <874m0otq02.fsf@bsb.me.uk>

Chris Angelico <rosuav at gmail.com> writes:
<snip>
> ... I teach JavaScript as well as Python, and I've seen some
> pretty horrendous indentation flaws (examples available if people ask
> privately, but I will anonymize them because I'm not here to shame
> students) - but there have been nearly as many cases where the
> indentation's fine and the bracket nesting isn't.

Can I ask what editor(s) your students have available?  I ask because
I've not given a moment's thought to indentation or what bracket matches
what for decades due to having a helpful editor.

<snip>
-- 
Ben.


From rosuav at gmail.com  Tue Jan 24 10:58:14 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 25 Jan 2017 02:58:14 +1100
Subject: How coding in Python is bad for you
In-Reply-To: <874m0otq02.fsf@bsb.me.uk>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
 <mailman.49.1485209394.2473.python-list@python.org>
 <o667tr$evq$1@dont-email.me>
 <CAPTjJmqftxV-cqkFtpijeqq83CP+Yx+jp1km82VK_OpKUZaRSg@mail.gmail.com>
 <mailman.53.1485219364.2473.python-list@python.org>
 <o66bjo$oqb$1@dont-email.me>
 <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>
 <mailman.55.1485225529.2473.python-list@python.org>
 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqupVWHHjnRHTPqxYmVjrtS_k7PdJY0JR_J3KjQTV1uXw@mail.gmail.com>
 <mailman.57.1485232893.2473.python-list@python.org> <874m0otq02.fsf@bsb.me.uk>
Message-ID: <CAPTjJmpzcTrhY94oTxSmO+3=4N+-Egp98WnE_vuZf4uvPVfNsg@mail.gmail.com>

On Wed, Jan 25, 2017 at 2:51 AM, Ben Bacarisse <ben.usenet at bsb.me.uk> wrote:
> Chris Angelico <rosuav at gmail.com> writes:
> <snip>
>> ... I teach JavaScript as well as Python, and I've seen some
>> pretty horrendous indentation flaws (examples available if people ask
>> privately, but I will anonymize them because I'm not here to shame
>> students) - but there have been nearly as many cases where the
>> indentation's fine and the bracket nesting isn't.
>
> Can I ask what editor(s) your students have available?  I ask because
> I've not given a moment's thought to indentation or what bracket matches
> what for decades due to having a helpful editor.
>

Quite a few, depending on which platform they're using. I'd say
Sublime is the most common choice.

ChrisA


From alister.ware at ntlworld.com  Tue Jan 24 11:03:45 2017
From: alister.ware at ntlworld.com (alister)
Date: Tue, 24 Jan 2017 16:03:45 GMT
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <o65nbu$mre$1@blaine.gmane.org>
 <CAPTjJmqh_jTGyZ0_v-JELxM--H=b-2azB3aSC5fSq1Hk38CpXQ@mail.gmail.com>
 <mailman.42.1485203128.2473.python-list@python.org>
 <RLthA.146356$c41.2628@fx40.am4>
 <slrno8cqj2.2ca.jon+usenet@sable.unequivocal.eu>
 <%tJhA.371507$1y4.144483@fx20.am4>
 <slrno8ep8b.3j6.jon+usenet@sable.unequivocal.eu>
Message-ID: <BVKhA.178901$vP3.3591@fx45.am4>

On Tue, 24 Jan 2017 14:28:55 +0000, Jon Ribbens wrote:

> On 2017-01-24, alister <alister.ware at ntlworld.com> wrote:
>> On Mon, 23 Jan 2017 20:39:26 +0000, Jon Ribbens wrote:
>>> That's a meaningless statement. *Everything* is a poison in sufficient
>>> quantities.
>>
>> indees when I here someone saying "I won't have any xyz because they
>> have heard that too much is bad for them" I invariably inform them that
>> too much oxygen is poisonous & challenge then to cut that out
>> completely :-)
> 
> Just wait until they find out that raw fruit and vegetables contain
> hundreds of chemicals!

then send them of to one of the sitre relating to Di-Hydrogen Monoxide...

I know of one organic food producer that has even tried to deny the use 
the stuff ;-)



-- 
AP/STT.  Helsinki, Dec 5th, 6:22 AM.  For immediate release.

In order to allay fears about the continuity of the Linux project, Linus
Torvalds together with his manager Tove Monni have released "Linus
v2.0", affectionately known as "Kernel Hacker - The Next Generation".

Linux stock prices on Wall Street rose sharply after the announcement;
as one well-known analyst who wishes to remain anonymous says - "It
shows a long-term commitment, and while we expect a short-term decrease
in productivity, we feel that this solidifies the development in the
long run".

Other analysts downplay the importance of the event, and claim that just
about anybody could have done it.  "I'm glad somebody finally told them
about the birds and the bees" one sceptic comments cryptically.  But
even the skeptics agree that it is an interesting turn of events.

Others bring up other issues with the new version - "I'm especially
intrigued by the fact that the new version is female, and look forward
to seeing what the impact of that will be on future development.  Will
"Red Hat Linux" change to "Pink Hat Linux", for example?"
	-- Linus Torvalds announcing that he became father of a girl


From ben.usenet at bsb.me.uk  Tue Jan 24 11:21:37 2017
From: ben.usenet at bsb.me.uk (Ben Bacarisse)
Date: Tue, 24 Jan 2017 16:21:37 +0000
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
 <mailman.49.1485209394.2473.python-list@python.org>
 <o667tr$evq$1@dont-email.me>
 <CAPTjJmqftxV-cqkFtpijeqq83CP+Yx+jp1km82VK_OpKUZaRSg@mail.gmail.com>
 <mailman.53.1485219364.2473.python-list@python.org>
 <o66bjo$oqb$1@dont-email.me>
 <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>
 <mailman.55.1485225529.2473.python-list@python.org>
 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqupVWHHjnRHTPqxYmVjrtS_k7PdJY0JR_J3KjQTV1uXw@mail.gmail.com>
 <mailman.57.1485232893.2473.python-list@python.org>
 <874m0otq02.fsf@bsb.me.uk>
 <CAPTjJmpzcTrhY94oTxSmO+3=4N+-Egp98WnE_vuZf4uvPVfNsg@mail.gmail.com>
 <mailman.66.1485273496.2473.python-list@python.org>
Message-ID: <87sho8sa26.fsf@bsb.me.uk>

Chris Angelico <rosuav at gmail.com> writes:

> On Wed, Jan 25, 2017 at 2:51 AM, Ben Bacarisse <ben.usenet at bsb.me.uk> wrote:
>> Chris Angelico <rosuav at gmail.com> writes:
>> <snip>
>>> ... I teach JavaScript as well as Python, and I've seen some
>>> pretty horrendous indentation flaws (examples available if people ask
>>> privately, but I will anonymize them because I'm not here to shame
>>> students) - but there have been nearly as many cases where the
>>> indentation's fine and the bracket nesting isn't.
>>
>> Can I ask what editor(s) your students have available?  I ask because
>> I've not given a moment's thought to indentation or what bracket matches
>> what for decades due to having a helpful editor.
>>
>
> Quite a few, depending on which platform they're using. I'd say
> Sublime is the most common choice.

So what's going in your opinion?  The errors are in the group who don't
use the right tools or what?

-- 
Ben.


From steve+python at pearwood.info  Tue Jan 24 11:35:56 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 25 Jan 2017 03:35:56 +1100
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
 <mailman.49.1485209394.2473.python-list@python.org>
 <o667tr$evq$1@dont-email.me>
 <CAPTjJmqftxV-cqkFtpijeqq83CP+Yx+jp1km82VK_OpKUZaRSg@mail.gmail.com>
 <mailman.53.1485219364.2473.python-list@python.org>
 <o66bjo$oqb$1@dont-email.me>
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 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
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 <874m0otq02.fsf@bsb.me.uk>
 <CAPTjJmpzcTrhY94oTxSmO+3=4N+-Egp98WnE_vuZf4uvPVfNsg@mail.gmail.com>
 <mailman.66.1485273496.2473.python-list@python.org>
 <87sho8sa26.fsf@bsb.me.uk>
Message-ID: <5887826d$0$1621$c3e8da3$5496439d@news.astraweb.com>

On Wed, 25 Jan 2017 03:21 am, Ben Bacarisse wrote:

> Chris Angelico <rosuav at gmail.com> writes:
> 
>> On Wed, Jan 25, 2017 at 2:51 AM, Ben Bacarisse <ben.usenet at bsb.me.uk>
>> wrote:
[...]
>>> Can I ask what editor(s) your students have available?  I ask because
>>> I've not given a moment's thought to indentation or what bracket matches
>>> what for decades due to having a helpful editor.
>>>
>>
>> Quite a few, depending on which platform they're using. I'd say
>> Sublime is the most common choice.
> 
> So what's going in your opinion?  The errors are in the group who don't
> use the right tools or what?


If braces can be inserted automatically by the compiler, then they are
useless and should be left out of the language.



-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From bc at freeuk.com  Tue Jan 24 11:37:52 2017
From: bc at freeuk.com (BartC)
Date: Tue, 24 Jan 2017 16:37:52 +0000
Subject: How coding in Python is bad for you
In-Reply-To: <874m0otq02.fsf@bsb.me.uk>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
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 <o66bjo$oqb$1@dont-email.me>
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 <mailman.57.1485232893.2473.python-list@python.org>
 <874m0otq02.fsf@bsb.me.uk>
Message-ID: <o67vpt$egb$1@dont-email.me>

On 24/01/2017 15:51, Ben Bacarisse wrote:
> Chris Angelico <rosuav at gmail.com> writes:
> <snip>
>> ... I teach JavaScript as well as Python, and I've seen some
>> pretty horrendous indentation flaws (examples available if people ask
>> privately, but I will anonymize them because I'm not here to shame
>> students) - but there have been nearly as many cases where the
>> indentation's fine and the bracket nesting isn't.
>
> Can I ask what editor(s) your students have available?  I ask because
> I've not given a moment's thought to indentation or what bracket matches
> what for decades due to having a helpful editor.

How would your editor detect the error in the example I gave earlier?

(Where a tab has been inadvertently removed - or added - but the result 
is still valid Python code.)

-- 
Bartc


From grant.b.edwards at gmail.com  Tue Jan 24 11:53:50 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Tue, 24 Jan 2017 16:53:50 +0000 (UTC)
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
 <mailman.49.1485209394.2473.python-list@python.org>
 <o667tr$evq$1@dont-email.me>
 <CAPTjJmqftxV-cqkFtpijeqq83CP+Yx+jp1km82VK_OpKUZaRSg@mail.gmail.com>
 <mailman.53.1485219364.2473.python-list@python.org>
 <o66bjo$oqb$1@dont-email.me>
 <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>
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 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqupVWHHjnRHTPqxYmVjrtS_k7PdJY0JR_J3KjQTV1uXw@mail.gmail.com>
 <mailman.57.1485232893.2473.python-list@python.org>
 <5886df70$0$11127$c3e8da3@news.astraweb.com>
 <CAPTjJmquAedGj+3k7OwMEVeWqB5z_dyq7CkUWdkX6bb=XYXYSg@mail.gmail.com>
Message-ID: <o680qu$d6m$1@blaine.gmane.org>

On 2017-01-24, Chris Angelico <rosuav at gmail.com> wrote:

> No no no. You have two orthogonal styles (indentation and tokens), but
> then you added another of the same style (another pair of tokens). You
> need a third orthogonal style. I suggest that each nesting level be
> heralded by an increase in indentation, an open brace, and a new text
> colour.

Bravo!

Actually, some news/mail readers pretty much do that with quote
levels, and it works pretty well.  Assuming you're not color blind,
don't care about hardcopy on monochrome printers, don't care about
screenreaders, don't use monochrome monitors, etc.

-- 
Grant Edwards               grant.b.edwards        Yow! I want the presidency
                                  at               so bad I can already taste
                              gmail.com            the hors d'oeuvres.



From __peter__ at web.de  Tue Jan 24 11:59:05 2017
From: __peter__ at web.de (Peter Otten)
Date: Tue, 24 Jan 2017 17:59:05 +0100
Subject: PhotoImage.paste
References: <d0476502-d414-4022-81e6-b28a648ac3ca@googlegroups.com>
Message-ID: <o6814l$uhd$1@blaine.gmane.org>

rryan.asu at gmail.com wrote:

> I'm trying to build a tkinter GUI with python 3.5, and would like to
> interactively adjust the color palette for an image by moving the mouse in
> the canvas using PIL.  In pseudo-code, I have something like
> 
> palette=color_map(x,y)   # x,y are scalars indicating the position of the
> mouse in the Canvas image.putpalette(palette)
> photo.paste(image)
> 
> This works just fine, but is very slow.  The photo.paste(image) step takes
> about 0.15 s (using an image that is 4k x 4k).  I read the manual on
> effbot, and they caution that the paste method would be slow if the image
> is display --- and I'm guessing that's what I'm doing.

So you have read

"""
Note: Pasting into an RGBA image that is displayed is a very slow operation. 
It?s usually better to create a new image object.
"""

on <http://effbot.org/imagingbook/imagetk.htm>.

> So my question is, what alternatives do I have to speed that step up.

Did you try to create a new image, as the note suggests?

> Thank you for any thoughts you might have...
> -Russell




From steve+python at pearwood.info  Tue Jan 24 12:07:57 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 25 Jan 2017 04:07:57 +1100
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
 <mailman.49.1485209394.2473.python-list@python.org>
 <o667tr$evq$1@dont-email.me>
 <CAPTjJmqftxV-cqkFtpijeqq83CP+Yx+jp1km82VK_OpKUZaRSg@mail.gmail.com>
 <mailman.53.1485219364.2473.python-list@python.org>
 <o66bjo$oqb$1@dont-email.me>
 <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>
 <mailman.55.1485225529.2473.python-list@python.org>
 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqupVWHHjnRHTPqxYmVjrtS_k7PdJY0JR_J3KjQTV1uXw@mail.gmail.com>
 <mailman.57.1485232893.2473.python-list@python.org>
 <o67f3g$g50$1@dont-email.me>
Message-ID: <588789ef$0$1583$c3e8da3$5496439d@news.astraweb.com>

On Tue, 24 Jan 2017 10:52 pm, BartC wrote:

>> if condition:
>>     statement
>> endif
>>     statement
>> endif
>>
>> What's this code meant to do? Can't know.
> 
> But whatever it does, a language that enforces 'endif' would report an
> error, so requiring further investigation. Without the 'endifs', it
> would look like this:
> 
> if condition:
>     statement
>     statement
> 
> Legal python.

Indeed. And 99.99% of the time it is correct Python as well.

I suspect that the use of redundant braces or end delimiters has something
to do with attitudes to risk. Or even, dare I say it, with confidence in
your own programming skill.

If (generic) you are risk adverse, or have low confidence in your ability,
then you might want all the help you can get from the compiler and insist
on having end delimiter for blocks. Think about how rare it is that it will
really matter: 

- you're editing an if block;
- and you do something that changes the block structure;
- but you do it wrong;
- and the failure is something which is still syntactically legal;
- but you don't notice;
- and the failure isn't instantly picked up by your tests;
- or you don't have tests which exercise that part of the code.

That's fairly unusually. How often does it happen? If you're a beginner, or
programming while high/drunk/sick/distracted, it might happen a lot. (I've
seen programmers who are seemingly incapable of writing `y = x + 1` without
six syntax errors and two logic errors.) But, I think, the average
half-decent coder should find that this isn't really a problem more than,
oh, once or twice a year. Or less.

By "a problem" I mean either a bug sneaks through into production, or they
find the bug but it takes more than an hour's debugging.

So if you're risk adverse, you're thinking about that wasted hour, or the
possibility of a bug sneaking into production code. (As if they don't
already, B&D compilers or not.)

But if you're more tolerant of risk (at least when it comes to coding), or
have more confidence in your ability, you might think:

- these bugs are rare;
- an hour isn't a long time to spend debugging;
- besides it probably won't be an hour;
- it's more likely to be five minutes with a debugger;
- and what's the worst that can happen? this isn't a nuclear power plant, 
  we'll fix the bug in the next release.

It's not that we don't see the benefit of those braces or end delimiters.
But we just don't think they're important enough to carry them around all
the time. Most of my `if` blocks are short, say, two or three lines. Adding
an "endif" after the block increases them by 33% or 50%. Multiply by the
hundreds, thousands, perhaps tens of thousands of block statements I'll
ever write or read, and that's a huge overhead for very little benefit.

And the next time I see a piece of code that ends:

                end
            end
        end
    end
end

the author is going to get a kickin'.

So for some of us, endif or however you want to spell it, is just noise,
eating up valuable vertical real estate. We recognise that it is
*theoretically* useful, but the *actual* usefulness in practice is so rare
that it really doesn't matter enough to make it worth while.

There's no right or wrong answer here. Once you get past the actual bug
magnets like C with its optional braces problem, and dangling elses, or
equivalent, the choice becomes one of taste.

There's a million brace-style languages out there for those who want them,
and only a handful like Python. Why can't you folks leave Python the way we
want it, instead of insisting it's wrong?


> Presumably you don't like parentheses in function calls for the same
> reasons; you'd prefer 'f a,b,c' rather than 'f(a,b,c)' in case, with
> copy&paste, someone might end up with: 'f(a,b,c),d)'.

No, because f a, b, c is ambigious.

spam(a, b, eggs(c, d), e)

would become in your system:

spam a, b, eggs c, d, e

and there's no way to tell which arguments are passed to eggs().

(Come on Bart, you've been designing languages for decades. You know this.)





-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From rosuav at gmail.com  Tue Jan 24 12:30:11 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 25 Jan 2017 04:30:11 +1100
Subject: How coding in Python is bad for you
In-Reply-To: <87sho8sa26.fsf@bsb.me.uk>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
 <mailman.49.1485209394.2473.python-list@python.org>
 <o667tr$evq$1@dont-email.me>
 <CAPTjJmqftxV-cqkFtpijeqq83CP+Yx+jp1km82VK_OpKUZaRSg@mail.gmail.com>
 <mailman.53.1485219364.2473.python-list@python.org>
 <o66bjo$oqb$1@dont-email.me>
 <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>
 <mailman.55.1485225529.2473.python-list@python.org>
 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqupVWHHjnRHTPqxYmVjrtS_k7PdJY0JR_J3KjQTV1uXw@mail.gmail.com>
 <mailman.57.1485232893.2473.python-list@python.org> <874m0otq02.fsf@bsb.me.uk>
 <CAPTjJmpzcTrhY94oTxSmO+3=4N+-Egp98WnE_vuZf4uvPVfNsg@mail.gmail.com>
 <mailman.66.1485273496.2473.python-list@python.org> <87sho8sa26.fsf@bsb.me.uk>
Message-ID: <CAPTjJmooLxGkrgd=1JuutbgAKoyWQDfcANrF16hOUgwbBq0dRA@mail.gmail.com>

On Wed, Jan 25, 2017 at 3:21 AM, Ben Bacarisse <ben.usenet at bsb.me.uk> wrote:
> Chris Angelico <rosuav at gmail.com> writes:
>
>> On Wed, Jan 25, 2017 at 2:51 AM, Ben Bacarisse <ben.usenet at bsb.me.uk> wrote:
>>> Chris Angelico <rosuav at gmail.com> writes:
>>> <snip>
>>>> ... I teach JavaScript as well as Python, and I've seen some
>>>> pretty horrendous indentation flaws (examples available if people ask
>>>> privately, but I will anonymize them because I'm not here to shame
>>>> students) - but there have been nearly as many cases where the
>>>> indentation's fine and the bracket nesting isn't.
>>>
>>> Can I ask what editor(s) your students have available?  I ask because
>>> I've not given a moment's thought to indentation or what bracket matches
>>> what for decades due to having a helpful editor.
>>>
>>
>> Quite a few, depending on which platform they're using. I'd say
>> Sublime is the most common choice.
>
> So what's going in your opinion?  The errors are in the group who don't
> use the right tools or what?

In my opinion, what's going on is that exploring code is a messy
process, and that the more little finicky things you have to get
right, the more likely you'll get something wrong. Which one you get
wrong is pretty much arbitrary.

Getting indentation wrong in JS won't affect the interpreter, but it
majorly affects the human. Which one would you rather confuse?

ChrisA


From bc at freeuk.com  Tue Jan 24 12:50:56 2017
From: bc at freeuk.com (BartC)
Date: Tue, 24 Jan 2017 17:50:56 +0000
Subject: How coding in Python is bad for you
In-Reply-To: <588789ef$0$1583$c3e8da3$5496439d@news.astraweb.com>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
 <mailman.49.1485209394.2473.python-list@python.org>
 <o667tr$evq$1@dont-email.me>
 <CAPTjJmqftxV-cqkFtpijeqq83CP+Yx+jp1km82VK_OpKUZaRSg@mail.gmail.com>
 <mailman.53.1485219364.2473.python-list@python.org>
 <o66bjo$oqb$1@dont-email.me>
 <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>
 <mailman.55.1485225529.2473.python-list@python.org>
 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqupVWHHjnRHTPqxYmVjrtS_k7PdJY0JR_J3KjQTV1uXw@mail.gmail.com>
 <mailman.57.1485232893.2473.python-list@python.org>
 <o67f3g$g50$1@dont-email.me>
 <588789ef$0$1583$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <o6842t$uoi$1@dont-email.me>

On 24/01/2017 17:07, Steve D'Aprano wrote:
> On Tue, 24 Jan 2017 10:52 pm, BartC wrote:
>
>>> if condition:
>>>     statement
>>> endif
>>>     statement
>>> endif
>>>
>>> What's this code meant to do? Can't know.
>>
>> But whatever it does, a language that enforces 'endif' would report an
>> error, so requiring further investigation. Without the 'endifs', it
>> would look like this:
>>
>> if condition:
>>     statement
>>     statement
>>
>> Legal python.
>
> Indeed.

> And 99.99% of the time it is correct Python as well.

You don't know that. If this has been pasted from elsewhere, you need to 
match up the indentation level with the current code.

> I suspect that the use of redundant braces or end delimiters has something
> to do with attitudes to risk. Or even, dare I say it, with confidence in
> your own programming skill.

(I'm in the early stages of implementing a C compiler at the moment. The 
test input is a single 750Kloc source file (900Kloc when 400 include 
files are taken account of).

If I've accidentally lost a space or tab while messing about with it, 
and it's significant, I would rather the compiler reported it! As I'm 
not going to spot it by perusing the 15,000 pages of code.)

> It's not that we don't see the benefit of those braces or end delimiters.
> But we just don't think they're important enough to carry them around all
> the time.

I don't use Python enough for it to be a problem, yet it /has/ been a 
problem. I paste code from elsewhere into my editor; usually the 
indentation is a mess of spaces, and usually the whole thing is indented 
if the imported from a post here.

But if you now try to manually fix the indentation, invariably there 
comes a point where you don't know if a particular line has the new 
indentation, or the old. The original structure is temporarily lost. 
Possibly permanently; you may have to refer to the original. Or, worse, 
you don't realise there is a mistake in the new indentation and the 
structure has been subtly altered.

This means that a straightforward tweak to a bit a source code is so 
error-prone that you are obliged to use automatic tools to do the job.

  Most of my `if` blocks are short, say, two or three lines. Adding
> an "endif" after the block increases them by 33% or 50%. Multiply by the
> hundreds, thousands, perhaps tens of thousands of block statements I'll
> ever write or read, and that's a huge overhead for very little benefit.
>
> And the next time I see a piece of code that ends:
>
>                 end
>             end
>         end
>     end
> end
>
> the author is going to get a kickin'.

Yes, but for using too much nesting!

Sometimes all these 'ends' are a nuisance, but IMO they are valuable, 
especially if they appear like this:

     end if
end for

as they give extra information. They can also inject extra vertical 
space which can be useful (although your example gives too much).

But they also TELL YOU that you are at the end of a set of blocks! In 
Python, the above wouldn't appear at all; if you're lucky, you'll get 
one blank line. Whether that signals the end of all five blocks, or 
three, or none, depends on what comes next: you have to scroll further 
and infer from that which of the blocks have terminated.

(I've mentioned in another thread the movie Monty Python and the Holy 
Grail, which doesn't have normal closing credits, just a black screen 
being projected. Eventually the audience realise there is nothing more 
to see... Just having 'The End' appear wouldn't be as quirky but it 
would save some time!)

> There's a million brace-style languages out there for those who want them,
> and only a handful like Python. Why can't you folks leave Python the way we
> want it, instead of insisting it's wrong?

Nothing's going to happen to Python and its unique block style. I'm just 
pointing out some of the flaws.

-- 
Bartc


From pkpearson at nowhere.invalid  Tue Jan 24 13:02:30 2017
From: pkpearson at nowhere.invalid (Peter Pearson)
Date: 24 Jan 2017 18:02:30 GMT
Subject: String Replacement
References: <fde3f369-8897-4d6d-a79f-15a4dc159d19@googlegroups.com>
Message-ID: <eepj5mFno9aU1@mid.individual.net>

On Mon, 23 Jan 2017 13:23:38 -0800 (PST), subhabangalore at gmail.com wrote:
> I have a string like 
>
> "Trump is $ the president of USA % Obama was $ the president
> of USA % Putin is $ the premier of Russia%"
>
> Here, I want to extract the portions from $...%, which would be
>
> "the president of USA", 
> "the president of USA", 
> "the premier of Russia"
[snip]

This might get you started:

$ cat temp.py
import re

x = ("Trump is $ the president of USA % Obama was $ the pres"
     "ident of USA % Putin is $ the premier of Russia%")

for y in re.finditer(r"(?P<first>[^\$]*)\$(?P<second>[^%]*)%", x):
    print("'{0}' -- '{1}'".format(y.group("first"), y.group("second")))

$ python3 temp.py
'Trump is ' -- ' the president of USA '
' Obama was ' -- ' the president of USA '
' Putin is ' -- ' the premier of Russia'



-- 
To email me, substitute nowhere->runbox, invalid->com.


From ben.usenet at bsb.me.uk  Tue Jan 24 14:21:08 2017
From: ben.usenet at bsb.me.uk (Ben Bacarisse)
Date: Tue, 24 Jan 2017 19:21:08 +0000
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
 <mailman.49.1485209394.2473.python-list@python.org>
 <o667tr$evq$1@dont-email.me>
 <CAPTjJmqftxV-cqkFtpijeqq83CP+Yx+jp1km82VK_OpKUZaRSg@mail.gmail.com>
 <mailman.53.1485219364.2473.python-list@python.org>
 <o66bjo$oqb$1@dont-email.me>
 <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>
 <mailman.55.1485225529.2473.python-list@python.org>
 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqupVWHHjnRHTPqxYmVjrtS_k7PdJY0JR_J3KjQTV1uXw@mail.gmail.com>
 <mailman.57.1485232893.2473.python-list@python.org>
 <874m0otq02.fsf@bsb.me.uk>
 <CAPTjJmpzcTrhY94oTxSmO+3=4N+-Egp98WnE_vuZf4uvPVfNsg@mail.gmail.com>
 <mailman.66.1485273496.2473.python-list@python.org>
 <87sho8sa26.fsf@bsb.me.uk>
 <5887826d$0$1621$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <87mvegs1qz.fsf@bsb.me.uk>

Steve D'Aprano <steve+python at pearwood.info> writes:

> On Wed, 25 Jan 2017 03:21 am, Ben Bacarisse wrote:
>
>> Chris Angelico <rosuav at gmail.com> writes:
>> 
>>> On Wed, Jan 25, 2017 at 2:51 AM, Ben Bacarisse <ben.usenet at bsb.me.uk>
>>> wrote:
> [...]
>>>> Can I ask what editor(s) your students have available?  I ask because
>>>> I've not given a moment's thought to indentation or what bracket matches
>>>> what for decades due to having a helpful editor.
>>>>
>>>
>>> Quite a few, depending on which platform they're using. I'd say
>>> Sublime is the most common choice.
>> 
>> So what's going in your opinion?  The errors are in the group who don't
>> use the right tools or what?
>
> If braces can be inserted automatically by the compiler, then they are
> useless and should be left out of the language.

I'm, not sure I agree but that would be a whole new topic.  I'm talking
about tools (editors specifically) that help the author to write what
they intend to write.

-- 
Ben.


From ben.usenet at bsb.me.uk  Tue Jan 24 14:31:18 2017
From: ben.usenet at bsb.me.uk (Ben Bacarisse)
Date: Tue, 24 Jan 2017 19:31:18 +0000
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <CAPTjJmrkiQSjyESJw-F7m+i371zo+m+_93du=1=Tqn+1qC=RTw@mail.gmail.com>
 <mailman.31.1485193216.2473.python-list@python.org>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
 <mailman.49.1485209394.2473.python-list@python.org>
 <o667tr$evq$1@dont-email.me>
 <CAPTjJmqftxV-cqkFtpijeqq83CP+Yx+jp1km82VK_OpKUZaRSg@mail.gmail.com>
 <mailman.53.1485219364.2473.python-list@python.org>
 <o66bjo$oqb$1@dont-email.me>
 <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>
 <mailman.55.1485225529.2473.python-list@python.org>
 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqupVWHHjnRHTPqxYmVjrtS_k7PdJY0JR_J3KjQTV1uXw@mail.gmail.com>
 <mailman.57.1485232893.2473.python-list@python.org>
 <874m0otq02.fsf@bsb.me.uk> <o67vpt$egb$1@dont-email.me>
Message-ID: <87h94os1a1.fsf@bsb.me.uk>

BartC <bc at freeuk.com> writes:

> On 24/01/2017 15:51, Ben Bacarisse wrote:
>> Chris Angelico <rosuav at gmail.com> writes:
>> <snip>
>>> ... I teach JavaScript as well as Python, and I've seen some
>>> pretty horrendous indentation flaws (examples available if people ask
>>> privately, but I will anonymize them because I'm not here to shame
>>> students) - but there have been nearly as many cases where the
>>> indentation's fine and the bracket nesting isn't.
>>
>> Can I ask what editor(s) your students have available?  I ask because
>> I've not given a moment's thought to indentation or what bracket matches
>> what for decades due to having a helpful editor.
>
> How would your editor detect the error in the example I gave earlier?

I'm not talking about detecting errors -- that's for the programmer --
but the editor can help the programmer to be sure they wrote what they
meant by doing things like matching brackets and auto-indenting code in
{}s.  (I'm replying to a post about JavaScript which has {}s.)

The trouble is that I've been programming for so long that I can't
remember what it's like to make block and/or indent errors.  Obviously I
make typos but they don't survive more than a few seconds.  I hoped that
Chris's students would provide an insight into how the tools do or
don't help.

> (Where a tab has been inadvertently removed - or added - but the
>result is still valid Python code.)

In Python the editor could, for example, highlight the block you are
typing in, so as soon as you leave the body of the 'if' it would stop
being marked and the containing code would be highlighted.  Just moving
the cursor up and down would show you what block everything is in.  I
don't know if any editors help like this -- that's part of my reason to
ask.

-- 
Ben.


From rryan.asu at gmail.com  Tue Jan 24 14:40:14 2017
From: rryan.asu at gmail.com (rryan.asu at gmail.com)
Date: Tue, 24 Jan 2017 11:40:14 -0800 (PST)
Subject: PhotoImage.paste
In-Reply-To: <mailman.68.1485277170.2473.python-list@python.org>
References: <d0476502-d414-4022-81e6-b28a648ac3ca@googlegroups.com>
 <o6814l$uhd$1@blaine.gmane.org>
 <mailman.68.1485277170.2473.python-list@python.org>
Message-ID: <609e413c-a2aa-4c63-8f60-125bb8c589ab@googlegroups.com>

Hi Peter,

Yes, that was the first thing I did, even before using the paste method.  I read the warning on effbot and other sites, and simply coded it up as

new_image.putpalette(palette)
photo=ImageTk.PhotoImage(image=new_image)
canvas_object=canvas.create_iamge(x,y,image=photo)

And this was a small bit faster, but still quite slow (say 0.1 s).  So just to understand the warning on effbot, I tried using paste, where'd I just do something like

image.putpalette(palette)
photo.paste(image)

and that took about 0.15 s. But my canvas has a few other things displayed on it, so each time that you create a new image/canvas object, I still have to run the lift method to order the items appropriately.  So all in all, the new image method wasn't that much better --- and ultimately still too slow for my interest.  

It seems that for some reason PIL just has this a limitation, which is really sad.  I think I can skirt the issue by when you start the mouse action, grab the bounding box from the view and only apply the new palette math to that subregion.  Then when the mouse action is finished, load the palette to the entire image with paste, and accept the time is 0.15 sec --- but this is not done in "real time".  This is will be a substantial amount of coding and quite ugly.  I'm just surprised that this is so clunky. 

Thanks for the suggestion.
Russell




On Tuesday, January 24, 2017 at 11:59:49 AM UTC-5, Peter Otten wrote:
>@gmail.com wrote:
> 
> > I'm trying to build a tkinter GUI with python 3.5, and would like to
> > interactively adjust the color palette for an image by moving the mouse in
> > the canvas using PIL.  In pseudo-code, I have something like
> > 
> > palette=color_map(x,y)   # x,y are scalars indicating the position of the
> > mouse in the Canvas image.putpalette(palette)
> > photo.paste(image)
> > 
> > This works just fine, but is very slow.  The photo.paste(image) step takes
> > about 0.15 s (using an image that is 4k x 4k).  I read the manual on
> > effbot, and they caution that the paste method would be slow if the image
> > is display --- and I'm guessing that's what I'm doing.
> 
> So you have read
> 
> """
> Note: Pasting into an RGBA image that is displayed is a very slow operation. 
> It?s usually better to create a new image object.
> """
> 
> on <http://effbot.org/imagingbook/imagetk.htm>.
> 
> > So my question is, what alternatives do I have to speed that step up.
> 
> Did you try to create a new image, as the note suggests?
> 
> > Thank you for any thoughts you might have...
> > -Russell


From ben.usenet at bsb.me.uk  Tue Jan 24 14:50:20 2017
From: ben.usenet at bsb.me.uk (Ben Bacarisse)
Date: Tue, 24 Jan 2017 19:50:20 +0000
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <o65u0i$b4c$1@dont-email.me>
 <CAPTjJmo6v1Vu3_Z9o2mPCb8dhUiwZQXZ-28ky+2dgiwQ_eukww@mail.gmail.com>
 <mailman.49.1485209394.2473.python-list@python.org>
 <o667tr$evq$1@dont-email.me>
 <CAPTjJmqftxV-cqkFtpijeqq83CP+Yx+jp1km82VK_OpKUZaRSg@mail.gmail.com>
 <mailman.53.1485219364.2473.python-list@python.org>
 <o66bjo$oqb$1@dont-email.me>
 <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>
 <mailman.55.1485225529.2473.python-list@python.org>
 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqupVWHHjnRHTPqxYmVjrtS_k7PdJY0JR_J3KjQTV1uXw@mail.gmail.com>
 <mailman.57.1485232893.2473.python-list@python.org>
 <874m0otq02.fsf@bsb.me.uk>
 <CAPTjJmpzcTrhY94oTxSmO+3=4N+-Egp98WnE_vuZf4uvPVfNsg@mail.gmail.com>
 <mailman.66.1485273496.2473.python-list@python.org>
 <87sho8sa26.fsf@bsb.me.uk>
 <CAPTjJmooLxGkrgd=1JuutbgAKoyWQDfcANrF16hOUgwbBq0dRA@mail.gmail.com>
 <mailman.69.1485279014.2473.python-list@python.org>
Message-ID: <87bmuws0eb.fsf@bsb.me.uk>

Chris Angelico <rosuav at gmail.com> writes:

> On Wed, Jan 25, 2017 at 3:21 AM, Ben Bacarisse <ben.usenet at bsb.me.uk> wrote:
>> Chris Angelico <rosuav at gmail.com> writes:
>>
>>> On Wed, Jan 25, 2017 at 2:51 AM, Ben Bacarisse <ben.usenet at bsb.me.uk> wrote:
>>>> Chris Angelico <rosuav at gmail.com> writes:
>>>> <snip>
>>>>> ... I teach JavaScript as well as Python, and I've seen some
>>>>> pretty horrendous indentation flaws (examples available if people ask
>>>>> privately, but I will anonymize them because I'm not here to shame
>>>>> students) - but there have been nearly as many cases where the
>>>>> indentation's fine and the bracket nesting isn't.
>>>>
>>>> Can I ask what editor(s) your students have available?  I ask because
>>>> I've not given a moment's thought to indentation or what bracket matches
>>>> what for decades due to having a helpful editor.
>>>>
>>>
>>> Quite a few, depending on which platform they're using. I'd say
>>> Sublime is the most common choice.
>>
>> So what's going in your opinion?  The errors are in the group who don't
>> use the right tools or what?
>
> In my opinion, what's going on is that exploring code is a messy
> process, and that the more little finicky things you have to get
> right, the more likely you'll get something wrong. Which one you get
> wrong is pretty much arbitrary.

Do you think the tools (the editor in particular) could be more helpful?
As I said elsewhere I've forgotten how these sorts of errors happen so I
have very little insight into how to prevent them.  With token-marked
blocks I feel (though I don't know) that matching and auto-indenting
help me to know I've written what I intended to write.  I was just
surprised that these errors happened enough for you to comment on them.

> Getting indentation wrong in JS won't affect the interpreter, but it
> majorly affects the human. Which one would you rather confuse?

I'm guessing that's a rhetorical question! (It obviously depends on the
situation.)  I suspect that part of the reason these errors occur is
precisely because they don't matter to the interpreter and students are
doing a lot of self-easement based on "does it work?" tests.  This is
why Python is a win in such situations -- you can't write confusingly
indented code, only wrong code.

-- 
Ben.


From rosuav at gmail.com  Tue Jan 24 16:19:20 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 25 Jan 2017 08:19:20 +1100
Subject: How an editor can help with block nesting (was Re: How coding in
 Python is bad for you)
Message-ID: <CAPTjJmqthQU7XgrieZgR=7jQPLtdBrjyZ+YERZqfpg2CvVaLLQ@mail.gmail.com>

On Wed, Jan 25, 2017 at 6:31 AM, Ben Bacarisse <ben.usenet at bsb.me.uk> wrote:
> I'm not talking about detecting errors -- that's for the programmer --
> but the editor can help the programmer to be sure they wrote what they
> meant by doing things like matching brackets and auto-indenting code in
> {}s.  (I'm replying to a post about JavaScript which has {}s.)
>
> The trouble is that I've been programming for so long that I can't
> remember what it's like to make block and/or indent errors.  Obviously I
> make typos but they don't survive more than a few seconds.  I hoped that
> Chris's students would provide an insight into how the tools do or
> don't help.
>
> In Python the editor could, for example, highlight the block you are
> typing in, so as soon as you leave the body of the 'if' it would stop
> being marked and the containing code would be highlighted.  Just moving
> the cursor up and down would show you what block everything is in.  I
> don't know if any editors help like this -- that's part of my reason to
> ask.

This is a huge topic, and worthy of its own thread.

I've toyed with a lot of different editors myself, and in the end, I
actually found that features like this are less valuable than having
an editor that's light on its toes and responds snappily even on
lower-end hardware (and I like using the same editor with the same
configs on all my systems). so I'm using SciTE. The most common editor
among my students is probably Sublime, followed by Atom, and they have
fairly similar feature sets.

Ultimately, programming is a messy business. You start out with an
imperfect idea of what you want, and progressively refine from there.
So anything that lets you "sketch" your code more easily is a good
thing. I think we can all agree on that part, right? It's just a
question of what _kind_ of help the editor gives.

The main two forms of help that I get or see from editors are:
1) Actually doing stuff for you, where it's 95% certain what you want
2) Visually showing you what your code is doing.

The first category includes stuff like auto-indentation (add an
indentation level when you have an open brace, or when there's a colon
ending the previous line), and the second category includes stuff that
highlights language keywords, or tells you about local vs global
names, or shows you where the matching bracket is for the one your
cursor's on.

I kinda like the idea of showing what the innermost active block
heading is for any given line of code. That would be fairly
straight-forward: scroll up till you find a non-blank line with less
indentation than the one you're on, and put a marker there. The
nearest equivalent I have is a feature that one of my cow-orkers asked
for once: a Python version of "jump to nearest brace". I bound it to
Ctrl-E, and played with the feature, but never really found it useful
- it was of mild value but I could generally eyeball it just as
easily. Would be curious to see how it works with a colour highlight
rather than an active "go to the top of this block" keystroke.
(Bikeshed: should _every_ active block heading be highlighted, or just
the innermost one? If you're inside a function, a loop, and a
condition, should the 'def', 'for', and 'if' lines all be
highlighted?)

With my JavaScript students, the greatest help is probably a keystroke
beautifier. You edit your code with sloppy indentation, and then bam,
it reindents for you. The trouble is that they can end up with code
where the indentation matches the braces, but *both are now wrong*.
I'd be very curious to see an "auto-bracket-closer" that adjusts the
brackets to match the indentation. Here's an example piece of
JavaScript - imagine this has been through a few rounds of editing:

function reducer(state=initial_state, action={}) {
    switch (action.type) {
        case 'FROBNOSTICATE':
            let items = info_store.filter((item) => {
                console.log("item:", item);
                return action.frob == item.frobbability;
            )}
            console.log("Keeping:", items)
            return {...state, frobbables: items}
        }
        default: break;
    }
    return state;
}

Now, I've deliberately made the indentation follow my intention, and
then messed up the brackets. An editor should be able to look at this
and pinpoint the places where the indentation changes unexpectedly,
and either automatically correct it, or raise an error (in the case of
the omitted open brace in the above example). I'd be curious to see
how well this works for people,  particularly novices. But it'd have
to be implemented first :)

Python removes some of this by not using braces for block delimiters,
but you can still get the same phenomenon with nested list/dict
displays, function calls, etc. So the code would be identical, except
that a colon at the end of a line indicates indentation too.

Anyone want to code this into an editor and see how it performs?

ChrisA


From this.wiederkehr at gmail.com  Tue Jan 24 16:31:44 2017
From: this.wiederkehr at gmail.com (This Wiederkehr)
Date: Tue, 24 Jan 2017 22:31:44 +0100
Subject: With class as contextmanager
Message-ID: <CAB6NXhg6yKKHASr-EUiz2=xvvSBEiNZFj97G5T9-Cgxh_PGtsQ@mail.gmail.com>

Hellou

having a class definition:

class Test():

@classmethod
def __enter__(cls):
    pass

@classmethod
def __exit__(cls, exception_type, execption_value, callback):
    pass

now using this as a contextmanager does not work, even though Test is an
object and has the two required methods __enter__ and __exit__.

it fails with:
#Attribute Error: __enter__


This is not working because behind the scene it does something like:
type(Test).__enter__(Test)

But isn't this supposed to be working?

I am asking because I'd like to implement the clean up behaviour for
multiple instances directly into the class:

with Test:
    testinstance1 = Test()
    testinstance2 = Test()
# on context exit Test.__exit__ should take care on cleaning up
testinstance1 and testinstance2.


Regards

This


From ian.g.kelly at gmail.com  Tue Jan 24 17:31:31 2017
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Tue, 24 Jan 2017 15:31:31 -0700
Subject: With class as contextmanager
In-Reply-To: <CAB6NXhg6yKKHASr-EUiz2=xvvSBEiNZFj97G5T9-Cgxh_PGtsQ@mail.gmail.com>
References: <CAB6NXhg6yKKHASr-EUiz2=xvvSBEiNZFj97G5T9-Cgxh_PGtsQ@mail.gmail.com>
Message-ID: <CALwzidnArVkbukJ5wcn=N0sVHvjXta33POMZxMvui5GZWw=vJA@mail.gmail.com>

On Tue, Jan 24, 2017 at 2:31 PM, This Wiederkehr
<this.wiederkehr at gmail.com> wrote:
> Hellou
>
> having a class definition:
>
> class Test():
>
> @classmethod
> def __enter__(cls):
>     pass
>
> @classmethod
> def __exit__(cls, exception_type, execption_value, callback):
>     pass
>
> now using this as a contextmanager does not work, even though Test is an
> object and has the two required methods __enter__ and __exit__.
>
> it fails with:
> #Attribute Error: __enter__
>
>
> This is not working because behind the scene it does something like:
> type(Test).__enter__(Test)
>
> But isn't this supposed to be working?
>
> I am asking because I'd like to implement the clean up behaviour for
> multiple instances directly into the class:
>
> with Test:
>     testinstance1 = Test()
>     testinstance2 = Test()
> # on context exit Test.__exit__ should take care on cleaning up
> testinstance1 and testinstance2.

Special dunder methods are generally only looked up on the object's
class, not on the object itself. If you wish to use a class object as a
context manager then you need to define __enter__ and __exit__ on the
class's class, i.e. its metaclass.

Alternatively you could separate the context manager from the testing
class and make Test be just an object that defines __enter__, __exit__
and __call__, with __call__ creating and returning a new instance of
the actual testing class.


From ethan at stoneleaf.us  Tue Jan 24 17:35:08 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 24 Jan 2017 14:35:08 -0800
Subject: With class as contextmanager
In-Reply-To: <CAB6NXhg6yKKHASr-EUiz2=xvvSBEiNZFj97G5T9-Cgxh_PGtsQ@mail.gmail.com>
References: <CAB6NXhg6yKKHASr-EUiz2=xvvSBEiNZFj97G5T9-Cgxh_PGtsQ@mail.gmail.com>
Message-ID: <5887D69C.9040909@stoneleaf.us>

On 01/24/2017 01:31 PM, This Wiederkehr wrote:

> having a class definition:
>
> class Test():
>
> @classmethod
> def __enter__(cls):
>      pass
>
> @classmethod
> def __exit__(cls, exception_type, execption_value, callback):
>      pass
>
> now using this as a contextmanager does not work, even though Test is an
> object and has the two required methods __enter__ and __exit__.

It is not working because you are trying to use the class itself, and not it's instances, as a context manager (which also means you don't need classmethod):

Wrong:

   with Test:

Correct:

   with Test():

> I am asking because I'd like to implement the clean up behaviour for
> multiple instances directly into the class:
>
> with Test:
>     testinstance1 = Test()
>     testinstance2 = Test()
> # on context exit Test.__exit__ should take care on cleaning up
> testinstance1 and testinstance2.

You might be able to make this work with a custom type (aka using a custom metaclass) -- but that could be a bunch of work.

--
~Ethan~


From hpj at urpla.net  Tue Jan 24 18:23:06 2017
From: hpj at urpla.net (Hans-Peter Jansen)
Date: Wed, 25 Jan 2017 00:23:06 +0100
Subject: Referencing section name by interpolation in ConfigParser
Message-ID: <4337515.1dgV1QdrqS@xrated>

Hi,

I would like to use a interpolated section name, e.g.:

[Section]
secref: %{section}s/whatever

should result in:

>>> config['Section']['secref']
'Section/whatever'

Any idea anybody, how to archive this with minimum fuzz?

Thanks,
Pete


From ethan at stoneleaf.us  Tue Jan 24 18:25:25 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 24 Jan 2017 15:25:25 -0800
Subject: With class as contextmanager
In-Reply-To: <5887D69C.9040909@stoneleaf.us>
References: <CAB6NXhg6yKKHASr-EUiz2=xvvSBEiNZFj97G5T9-Cgxh_PGtsQ@mail.gmail.com>
 <5887D69C.9040909@stoneleaf.us>
Message-ID: <5887E265.4000700@stoneleaf.us>

On 01/24/2017 02:35 PM, Ethan Furman wrote:
> On 01/24/2017 01:31 PM, This Wiederkehr wrote:

>> having a class definition:
>>
>> class Test():
>>
>> @classmethod
>> def __enter__(cls):
>>      pass
>>
>> @classmethod
>> def __exit__(cls, exception_type, execption_value, callback):
>>      pass
>>
>> now using this as a contextmanager does not work, even though Test is an
>> object and has the two required methods __enter__ and __exit__.
>
> It is not working because you are trying to use the class itself, and not it's instances, as a context manager (which also means you don't need classmethod):
>
> Wrong:
>
>    with Test:
>
> Correct:
>
>    with Test():
>
>> I am asking because I'd like to implement the clean up behaviour for
>> multiple instances directly into the class:
>>
>> with Test:
>>     testinstance1 = Test()
>>     testinstance2 = Test()
>> # on context exit Test.__exit__ should take care on cleaning up
>> testinstance1 and testinstance2.
>
> You might be able to make this work with a custom type (aka using a custom metaclass) -- but that could be a bunch of work.

Okay, here's the easy part:

--- 8< ----------------------------
class TestType(type):
     def __enter__(cls):
         pass
     def __exit__(cls, *args):
         pass

class Test(metaclass=TestType):
     pass

with Test:
     print('worked!')
--- 8< ----------------------------

Let us know how it turns out.

--
~Ethan~


From steve+python at pearwood.info  Tue Jan 24 20:31:11 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Wed, 25 Jan 2017 12:31:11 +1100
Subject: How an editor can help with block nesting (was Re: How coding in
 Python is bad for you)
References: <CAPTjJmqthQU7XgrieZgR=7jQPLtdBrjyZ+YERZqfpg2CvVaLLQ@mail.gmail.com>
 <mailman.70.1485292804.2473.python-list@python.org>
Message-ID: <5887ffe2$0$1603$c3e8da3$5496439d@news.astraweb.com>

On Wed, 25 Jan 2017 08:19 am, Chris Angelico wrote:

> I kinda like the idea of showing what the innermost active block
> heading is for any given line of code. That would be fairly
> straight-forward: scroll up till you find a non-blank line with less
> indentation than the one you're on, and put a marker there. The
> nearest equivalent I have is a feature that one of my cow-orkers asked
> for once: a Python version of "jump to nearest brace". I bound it to
> Ctrl-E, and played with the feature, but never really found it useful
> - it was of mild value but I could generally eyeball it just as
> easily. 

Indeed. Good programming practice suggests that your block should ideally be
under half an dozen lines and certainly less than a full screenful. If you
need a command to jump to the top or bottom of the block, your blocks are
too big and need refactoring.


> Would be curious to see how it works with a colour highlight 
> rather than an active "go to the top of this block" keystroke.
> (Bikeshed: should _every_ active block heading be highlighted, or just
> the innermost one? If you're inside a function, a loop, and a
> condition, should the 'def', 'for', and 'if' lines all be
> highlighted?)

I actually don't see the point.

For an experienced coder, you already have all the clue you need to see the
block structure: the indentation level.

(If you are indenting by a single space, or even two spaces, you're probably 
hamstringing yourself and hurting your ability to recognise structure at a
glance.)

Adding an extra colour cue to duplicate the information given by indentation
just adds to the noise level of code. But if you were to do the experiment,
I'd *only* colour the currently edited block, by marking the margins with a
subtle colour. You know how many GUI editors highlight the current line
with a faint colour? Something similar. You could make the colour different
for each block, I guess, if you wanted to be fancy.


> With my JavaScript students, the greatest help is probably a keystroke
> beautifier. You edit your code with sloppy indentation, and then bam,
> it reindents for you. 

Really? I wouldn't want that, or find it helpful to type badly formatted
code. I would want one of two things:

(1) Indentation is up to you. You either get it syntactically right, or the
code won't run, like Python. That teaches you to get the indentation right
through negative reinforcement.

Of course merely getting the indentation syntactically correct doesn't mean
it is *semantically* correct, but the editor or compiler doesn't know what
you mean, only what you say. If you cannot get the syntax right, you can't
hope to communicate to the compiler. So learning to get the syntax right is
a necessary first step to learning to program.


(2) Or the editor won't let you enter sloppy indentation in the first place.
This teaches you good indentation by example.

Every time you hit return, the editor automatically indents as needed. If
you mistakenly change the indentation (or fail to change the indentation
when needed), then when you hit return on that line (or any other editing
command that moves to another line), the editor either fixes the
indentation for you, if it can, or flags the line as a syntax error if it
cannot determine the right thing to do.


For example, suppose I already have this, where | is the current text
insertion point:

    def func(a, b):
        if condition:
            spam() |

I hit ENTER, and the editor automatically indents to the current block
level. There's nothing new about that, most editors already do this:


    def func(a, b):
        if condition:
            spam()
            |

But now I type something which cannot possibly be indented there:

    def func(a, b):
        if condition:
            spam()
            elif something: |

and hit ENTER again. There's nothing ambiguous about this, and the editor
could (and should?) re-indent the elif line, giving this:

    def func(a, b):
        if condition:
            spam()
        elif something:
            |

In other words, with the second scenario, you can never have more than one
mis-indented line at a time during the normal course of editing. (At least
not without really working to defeat the editor.)




-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From dan at tombstonezero.net  Tue Jan 24 20:44:20 2017
From: dan at tombstonezero.net (Dan Sommers)
Date: Wed, 25 Jan 2017 01:44:20 -0000 (UTC)
Subject: How an editor can help with block nesting (was Re: How coding in
 Python is bad for you)
References: <CAPTjJmqthQU7XgrieZgR=7jQPLtdBrjyZ+YERZqfpg2CvVaLLQ@mail.gmail.com>
 <mailman.70.1485292804.2473.python-list@python.org>
 <5887ffe2$0$1603$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <o68vtj$uu2$1@dont-email.me>

On Wed, 25 Jan 2017 12:31:11 +1100, Steve D'Aprano wrote:

> But now I type something which cannot possibly be indented there:
> 
>     def func(a, b):
>         if condition:
>             spam()
>             elif something: |
> 
> and hit ENTER again. There's nothing ambiguous about this, and the
> editor could (and should?) re-indent the elif line, giving this:
> 
>     def func(a, b):
>         if condition:
>             spam()
>         elif something:
>             |
> 
> In other words, with the second scenario, you can never have more than
> one mis-indented line at a time during the normal course of
> editing. (At least not without really working to defeat the editor.)

And then you get to this one:

    def f(x):
        if condition:
            spam()
            if g(x):
                eggs()
                elif something_else: |

Now, everyone, say it with me:  In the face of ambiguity, refuse the
temptation to guess.

In languages with braces, re-indenting lines as I press ENTER is
possible (I happen not to like that behavior, but that's a personal
preference, and editors that won't get out of the way and let me edit my
own code get deleted).

In Python, I prefer to get the indent right myself before I press ENTER.

Dan


From rosuav at gmail.com  Tue Jan 24 20:47:28 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 25 Jan 2017 12:47:28 +1100
Subject: How an editor can help with block nesting (was Re: How coding in
 Python is bad for you)
In-Reply-To: <5887ffe2$0$1603$c3e8da3$5496439d@news.astraweb.com>
References: <CAPTjJmqthQU7XgrieZgR=7jQPLtdBrjyZ+YERZqfpg2CvVaLLQ@mail.gmail.com>
 <mailman.70.1485292804.2473.python-list@python.org>
 <5887ffe2$0$1603$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmoj7Kku8J99HgLXVMhHUvMqmOQA90HZOvmKq-b2-Eq=Vg@mail.gmail.com>

On Wed, Jan 25, 2017 at 12:31 PM, Steve D'Aprano
<steve+python at pearwood.info> wrote:
>> With my JavaScript students, the greatest help is probably a keystroke
>> beautifier. You edit your code with sloppy indentation, and then bam,
>> it reindents for you.
>
> Really? I wouldn't want that, or find it helpful to type badly formatted
> code.

This isn't something I use (when I want a beautifier, it's because I'm
de-minifying some code to figure out what it does, so I just paste it
into http://jsbeautifier.org/ or something), but I've seen my students
move braces around and then hit the beautifier, where I would
highlight the text and hit Tab or Shift-Tab to adjust the indentation
level.

> I would want one of two things:
>
> (1) Indentation is up to you. You either get it syntactically right, or the
> code won't run, like Python. That teaches you to get the indentation right
> through negative reinforcement.
>
> (2) Or the editor won't let you enter sloppy indentation in the first place.
> This teaches you good indentation by example.
>
> [chomp details of entering code for the first time]

Tell me, how often do you enter code and it works the first time? :)

Much more common - and this is especially true of student programmers,
but we're none of us immune to it - the code gets tinkered with and
edited and manipulated many times before it's finally working. Stuff
gets reordered, conditionals get added or removed, etc, etc, etc. So
there are a few possibilities:

1) Get the symbols right, then adjust the indentation to match
2) Get the indentation right, then adjust the symbols to match
3) Check before permitting code to be committed, and reject if they don't match
4) Check before permitting code even to be run
5) Ignore the indentation because it "doesn't matter", and then waste
your instructor's time when you call him in to help you figure out
where your bug is.

Python makes the second option easier (by having no symbols for the
most common indentation), but doesn't eliminate the problem entirely.
The fifth option is what most often happens. The first is the "hit the
beautifier key" option, and is fine as long as you absolutely
definitely got the symbols right. I'm thinking the third or fourth
might be the best :)

ChrisA


From bc at freeuk.com  Tue Jan 24 20:50:43 2017
From: bc at freeuk.com (BartC)
Date: Wed, 25 Jan 2017 01:50:43 +0000
Subject: How coding in Python is bad for you
In-Reply-To: <mailman.77.1485306290.2473.python-list@python.org>
References: <o66bjo$oqb$1@dont-email.me>
 <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>
 <mailman.55.1485225529.2473.python-list@python.org>
 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqupVWHHjnRHTPqxYmVjrtS_k7PdJY0JR_J3KjQTV1uXw@mail.gmail.com>
 <mailman.57.1485232893.2473.python-list@python.org>
 <o67f3g$g50$1@dont-email.me>
 <588789ef$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <o6842t$uoi$1@dont-email.me> <kltf8ctjhg67s3n4dl83u58meg5oueqkqq@4ax.com>
 <mailman.77.1485306290.2473.python-list@python.org>
Message-ID: <o6906g$1jr$1@dont-email.me>

On 25/01/2017 01:04, Dennis Lee Bieber wrote:
> On Tue, 24 Jan 2017 17:50:56 +0000, BartC <bc at freeuk.com> declaimed the
> following:

>> If I've accidentally lost a space or tab while messing about with it,
>> and it's significant, I would rather the compiler reported it! As I'm
>> not going to spot it by perusing the 15,000 pages of code.)
>>
> 	None of the C/Java/Pascal/Ada family will report a missing space or
> tab.

The point is, it usually doesn't matter as in most situations it's not 
significant. But if it was significant it would be useful for the 
language to pick it up. (Usually it would be in such languages, but not 
always.)

And if C code is posted on usenet, and leading whitespace is lost, as 
often happens, then the results are still valid code.

Losing leading white space with Python code would cause serious problems 
as it contains program structure that is not backed up by explicit block 
markers (which could have been used to reconstruct the indentation).


-- 
Bartc


From python.list at tim.thechases.com  Tue Jan 24 20:54:30 2017
From: python.list at tim.thechases.com (Tim Chase)
Date: Tue, 24 Jan 2017 19:54:30 -0600
Subject: How coding in Python is bad for you
In-Reply-To: <kltf8ctjhg67s3n4dl83u58meg5oueqkqq@4ax.com>
References: <o66bjo$oqb$1@dont-email.me>
 <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>
 <mailman.55.1485225529.2473.python-list@python.org>
 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqupVWHHjnRHTPqxYmVjrtS_k7PdJY0JR_J3KjQTV1uXw@mail.gmail.com>
 <mailman.57.1485232893.2473.python-list@python.org>
 <o67f3g$g50$1@dont-email.me>
 <588789ef$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <o6842t$uoi$1@dont-email.me>
 <kltf8ctjhg67s3n4dl83u58meg5oueqkqq@4ax.com>
Message-ID: <20170124195430.6c7dcafc@bigbox.christie.dr>

On 2017-01-24 20:04, Dennis Lee Bieber wrote:
>>You don't know that. If this has been pasted from elsewhere, you
>>need to match up the indentation level with the current code.
> 
> 	So? The editor(s) I tend to use have the ability to shift
> indent in/out for selected blocks. Do the paste, highlight the
> pasted content, and shift the indent as needed.

The editor I use (vim) doesn't even require me to re-select the range
to shift it.  Just using

  >']

or

  <']

will indent/dedent from the cursor to the line where your paste ended.

Hurray for laziness :-)

-tkc




From tjreedy at udel.edu  Tue Jan 24 21:21:02 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Tue, 24 Jan 2017 21:21:02 -0500
Subject: With class as contextmanager
In-Reply-To: <CAB6NXhg6yKKHASr-EUiz2=xvvSBEiNZFj97G5T9-Cgxh_PGtsQ@mail.gmail.com>
References: <CAB6NXhg6yKKHASr-EUiz2=xvvSBEiNZFj97G5T9-Cgxh_PGtsQ@mail.gmail.com>
Message-ID: <o6922a$di5$1@blaine.gmane.org>

On 1/24/2017 4:31 PM, This Wiederkehr wrote:

> having a class definition:
>
> class Test():
>
> @classmethod
> def __enter__(cls):
>     pass
>
> @classmethod
> def __exit__(cls, exception_type, execption_value, callback):
>     pass
>
> now using this as a contextmanager does not work, even though Test is an
> object and has the two required methods __enter__ and __exit__.
>
> it fails with:
> #Attribute Error: __enter__
>
>
> This is not working because behind the scene it does something like:
> type(Test).__enter__(Test)
>
> But isn't this supposed to be working?

No.  Unqualified 'method' means instance method, not class method.

One can simulate instance methods like so:

 >>> import types
 >>> def f(self): print('f called')

 >>> class C: pass

 >>> c = C()
 >>> c.m = types.MethodType(f, c)
 >>> c.m()
f called

However, this will not work for dunder methods where the lookup for the 
method starts with the class and not the object itself.

 >>> def h(self): return 1

 >>> c.__hash__ = types.MethodType(h, c)
 >>> hash(c)  # calls type(c).__hash__, not c.__hash__
-9223371924496369383

-- 
Terry Jan Reedy



From greg.ewing at canterbury.ac.nz  Tue Jan 24 23:44:51 2017
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Wed, 25 Jan 2017 17:44:51 +1300
Subject: How coding in Python is bad for you
In-Reply-To: <mailman.78.1485306617.2473.python-list@python.org>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <o65nbu$mre$1@blaine.gmane.org>
 <CAPTjJmqh_jTGyZ0_v-JELxM--H=b-2azB3aSC5fSq1Hk38CpXQ@mail.gmail.com>
 <mailman.42.1485203128.2473.python-list@python.org>
 <RLthA.146356$c41.2628@fx40.am4>
 <slrno8cqj2.2ca.jon+usenet@sable.unequivocal.eu>
 <%tJhA.371507$1y4.144483@fx20.am4>
 <slrno8ep8b.3j6.jon+usenet@sable.unequivocal.eu>
 <BVKhA.178901$vP3.3591@fx45.am4> <4iuf8clgqekpr1jkf9danh99h4eedd5ptb@4ax.com>
 <mailman.78.1485306617.2473.python-list@python.org>
Message-ID: <eeqoq5F23tsU1@mid.individual.net>

Dennis Lee Bieber wrote:
> 	While I'm trying to figure out what significance Centrum vitamins have
> with being "non-GMO"...

Possibly they're just complying with some legal requirement or
other to declare whether the product has any GMO components.
If so, bit of a silly regulation, I'll agree. What we really
want to know is whether they use any dihydrogen monoxide in the
manufacturing process!

-- 
Greg


From greg.ewing at canterbury.ac.nz  Tue Jan 24 23:51:24 2017
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Wed, 25 Jan 2017 17:51:24 +1300
Subject: PhotoImage.paste
In-Reply-To: <mailman.79.1485307875.2473.python-list@python.org>
References: <d0476502-d414-4022-81e6-b28a648ac3ca@googlegroups.com>
 <2c6196b4-89ac-6111-cb13-5062bf538297@mrabarnett.plus.com>
 <mailman.64.1485263317.2473.python-list@python.org>
 <e6f3f915-9bbe-41cf-8594-4a2e6dee9550@googlegroups.com>
 <61vf8c580fkmpm4jr7mmf928tgfmu7bmb4@4ax.com>
 <mailman.79.1485307875.2473.python-list@python.org>
Message-ID: <eeqp6eF26ioU1@mid.individual.net>

Dennis Lee Bieber wrote:
> 	But practically everything these days uses true/high color, in which
> each pixel encodes the exact color to be displayed. This means that
> changing all matching pixels from one given color to another given color
> requires rewriting those pixels color data.

Yes, and a 4k x 4k RGBA image is about 64MB of data.
I'm not surprised it takes a noticeable amount of
time to change all of that.

-- 
Greg


From cmalliopoulos at gmail.com  Wed Jan 25 01:38:08 2017
From: cmalliopoulos at gmail.com (Christos Malliopoulos)
Date: Wed, 25 Jan 2017 06:38:08 +0000
Subject: configparser bug
In-Reply-To: <CAMuzKSso0uxFcS8mQbBeY44rAUHy3rwXd4CL6qnMDQXger+7hg@mail.gmail.com>
References: <CAMuzKSso0uxFcS8mQbBeY44rAUHy3rwXd4CL6qnMDQXger+7hg@mail.gmail.com>
Message-ID: <CAMuzKSt+5eV+wefoU6Lf4dHgvph8p9kWw7yiD+qzeKqbMeY4_A@mail.gmail.com>

Hi,

I run Ubuntu 16.04 LTS in a VM using VMWare Workstation on a Windows 10
host.
apt show python-configparser shows 3.3.0r2-2
On python 2.7.12 I use the following code:

import configparser as cfg
root =
u'/'.join(os.path.split(os.path.abspath('cfg.py'))[0].split('/')[:-2])
cp = cfg.ConfigParser(interpolation = cfg.ExtendedInterpolation())
cp.read(os.path.abspath(os.path.join(root, u'config/sampling.cfg')))

cp.items('Sampling')

sampling.cfg contains the following lines:
[Sampling]
    nobs = 10
    nzin = 4
    nzout = 3
    ndrops = 1

    inh = day,loc,z0,value
    outh = day,loc,sku,value

    invalran = 1,1e3
    outvalran = 1,1000

cp.items(u'Sampling') prints the following:
[(u'nobs', u'10'),
 (u'nzin', u'4'),
 (u'nzout', u'3\nndrops = 1'),
 (u'inh', u'day,loc,z0,value'),
 (u'outh', u'day,loc,sku,value'),
 (u'invalran', u'1,1e3'),
 (u'outvalran', u'1,1000')]

ndrops = 1 is not parsed correctly


From tonytonytony0724 at gmail.com  Wed Jan 25 02:22:21 2017
From: tonytonytony0724 at gmail.com (Tony Chen)
Date: Tue, 24 Jan 2017 23:22:21 -0800 (PST)
Subject: any one used moviepy please come in!!! I need help, thanks!
Message-ID: <5ec6d36f-5200-4882-98ce-c317deab35b3@googlegroups.com>

I have to use moviepy in one of my project. So I downloaded it, and tried the example code on the website. It gives me this error. Anyone can give me some help? Thank you very much!

it gives this error:
[MoviePy] This command returned an error !Traceback (most recent call last):
  File "tst.py", line 5, in <module>
    txt_clip = TextClip("My Holidays 2013", fontsize = 70, color = 'white')
  File "/usr/local/lib/python2.7/dist-packages/moviepy/video/VideoClip.py", line 1145, in __init__
    raise IOError(error)
IOError: MoviePy Error: creation of None failed because of the following error:

convert: not authorized `@/tmp/tmpjistPm.txt' @ error/property.c/InterpretImageProperties/3405.
convert: no images defined `PNG32:/tmp/tmpJM0NVq.png' @ error/convert.c/ConvertImageCommand/3210.
.

.This error can be due to the fact that ImageMagick is not installed on your computer, or (for Windows users) that you didn't specify the path to the ImageMagick binary in file conf.py, or.that the path you specified is incorrect


From rosuav at gmail.com  Wed Jan 25 02:33:46 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 25 Jan 2017 18:33:46 +1100
Subject: any one used moviepy please come in!!! I need help, thanks!
In-Reply-To: <5ec6d36f-5200-4882-98ce-c317deab35b3@googlegroups.com>
References: <5ec6d36f-5200-4882-98ce-c317deab35b3@googlegroups.com>
Message-ID: <CAPTjJmov+oqYy7MHdE=vBBHprCULyPXercYbsO=XAxE+MrE85Q@mail.gmail.com>

On Wed, Jan 25, 2017 at 6:22 PM, Tony Chen <tonytonytony0724 at gmail.com> wrote:
> This error can be due to the fact that ImageMagick is not installed on your computer, or (for Windows users) that you didn't specify the path to the ImageMagick binary in file conf.py, or.that the path you specified is incorrect

So... is ImageMagick installed?

ChrisA


From hmmeeranrizvi18 at gmail.com  Wed Jan 25 02:45:01 2017
From: hmmeeranrizvi18 at gmail.com (hmmeeranrizvi18 at gmail.com)
Date: Tue, 24 Jan 2017 23:45:01 -0800 (PST)
Subject: Hide text in entry box when i click on it.(GUI using Tkinter in
 python)
Message-ID: <01419236-7cb8-498e-b3bb-9f209b1db53e@googlegroups.com>

Hello Guys,
Here i am creating a entry box with some text,i need to hide the text when i click on it.
Here is my code

from Tkinter import *
obj = Tk()
b = Entry(obj,width=100)
b.insert(0,"Enter the value to search")
b.pack()
mainloop()



From bob.martin at excite.com  Wed Jan 25 02:53:57 2017
From: bob.martin at excite.com (Bob Martin)
Date: Wed, 25 Jan 2017 07:53:57 GMT
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <mailman.59.1485241736.2473.python-list@python.org>
Message-ID: <eer3slF45n2U1@mid.individual.net>

in 770220 20170124 070853 Chris Angelico <rosuav at gmail.com> wrote:
>On Tue, Jan 24, 2017 at 6:00 PM, Bob Martin <bob.martin at excite.com> wrote:
>> in 770207 20170124 005601 Chris Angelico <rosuav at gmail.com> wrote:
>>
>>>REXX has even less structure than Python - it doesn't even have
>>>functions, just labels, so you can actually have two functions that
>>>share a common tail. And yes, you can abuse that horrendously to
>>>create unreadable code. Is REXX a bad language because of that? No.
>>>You can use structure badly, and you can use freedom badly.
>>
>> Of course Rexx has functions!
>
>Built-ins, yes, but when you define your own, it's by giving a label.
>It isn't a function until it's called as a function.

Just because the word "function" isn't in the header doesn't change matters.
The word "procedure" can appear in the header, but it can be called as a
procedure or a function. 


From __peter__ at web.de  Wed Jan 25 04:01:56 2017
From: __peter__ at web.de (Peter Otten)
Date: Wed, 25 Jan 2017 10:01:56 +0100
Subject: Referencing section name by interpolation in ConfigParser
References: <4337515.1dgV1QdrqS@xrated>
Message-ID: <o69phv$h0v$1@blaine.gmane.org>

Hans-Peter Jansen wrote:

> I would like to use a interpolated section name, e.g.:
> 
> [Section]
> secref: %{section}s/whatever
> 
> should result in:
> 
>>>> config['Section']['secref']
> 'Section/whatever'
> 
> Any idea anybody, how to archive this with minimum fuzz?

If you can live with the existing "basic interpolation", i. e. %(...)s, not 
%{...}s:

$ cat config.ini
[Foo]
secref: %(section)s/whatever
[Bar]
secref: %(section)s/whatever
$ cat demo.py
import configparser


class Interpolation(configparser.BasicInterpolation):
    def before_get(self, parser, section, option, value, defaults):
        defaults = defaults.copy()
        defaults["section"] = section
        return super().before_get(parser, section, option, value, defaults)


p = configparser.ConfigParser(interpolation=Interpolation())
p.read("config.ini")
for section in "Foo", "Bar":
    print(section, "-->", p[section]["secref"])
$ python3 demo.py 
Foo --> Foo/whatever
Bar --> Bar/whatever
$



From __peter__ at web.de  Wed Jan 25 04:18:41 2017
From: __peter__ at web.de (Peter Otten)
Date: Wed, 25 Jan 2017 10:18:41 +0100
Subject: Hide text in entry box when i click on it.(GUI using Tkinter in
 python)
References: <01419236-7cb8-498e-b3bb-9f209b1db53e@googlegroups.com>
Message-ID: <o69qhc$h91$1@blaine.gmane.org>

hmmeeranrizvi18 at gmail.com wrote:

> Hello Guys,
> Here i am creating a entry box with some text,i need to hide the text when
> i click on it. Here is my code
> 
> from Tkinter import *
> obj = Tk()
> b = Entry(obj,width=100)
> b.insert(0,"Enter the value to search")
> b.pack()
> mainloop()

You need to bind a callback function to a mouse event:

import Tkinter as tk

def clear_search(event):
    search.delete(0, tk.END)

root = tk.Tk()

search = tk.Entry(root, width=100)
search.insert(0, "Enter the value to search")
search.pack()
search.bind("<Button-1>", clear_search)

root.mainloop()

This will always clear the Entry; you probably want to check if it contains 
the initial message first to avoid that the user accidentally loses input.



From hmmeeranrizvi18 at gmail.com  Wed Jan 25 04:53:03 2017
From: hmmeeranrizvi18 at gmail.com (hmmeeranrizvi18 at gmail.com)
Date: Wed, 25 Jan 2017 01:53:03 -0800 (PST)
Subject: Hide text in entry box when i click on it.(GUI using Tkinter in
 python)
In-Reply-To: <01419236-7cb8-498e-b3bb-9f209b1db53e@googlegroups.com>
References: <01419236-7cb8-498e-b3bb-9f209b1db53e@googlegroups.com>
Message-ID: <e73e4ab4-6f6d-40cb-909e-7ddc8655ed5d@googlegroups.com>

On Wednesday, January 25, 2017 at 1:15:11 PM UTC+5:30, hmmeera... at gmail.com wrote:
> Hello Guys,
> Here i am creating a entry box with some text,i need to hide the text when i click on it.
> Here is my code
> 
> from Tkinter import *
> obj = Tk()
> b = Entry(obj,width=100)
> b.insert(0,"Enter the value to search")
> b.pack()
> mainloop()

Thanks Peter


From __peter__ at web.de  Wed Jan 25 06:30:56 2017
From: __peter__ at web.de (Peter Otten)
Date: Wed, 25 Jan 2017 12:30:56 +0100
Subject: configparser bug
References: <CAMuzKSso0uxFcS8mQbBeY44rAUHy3rwXd4CL6qnMDQXger+7hg@mail.gmail.com>
 <CAMuzKSt+5eV+wefoU6Lf4dHgvph8p9kWw7yiD+qzeKqbMeY4_A@mail.gmail.com>
Message-ID: <o6a29b$li6$1@blaine.gmane.org>

Christos Malliopoulos wrote:

> Hi,
> 
> I run Ubuntu 16.04 LTS in a VM using VMWare Workstation on a Windows 10
> host.
> apt show python-configparser shows 3.3.0r2-2
> On python 2.7.12 I use the following code:
> 
> import configparser as cfg
> root =
> u'/'.join(os.path.split(os.path.abspath('cfg.py'))[0].split('/')[:-2])
> cp = cfg.ConfigParser(interpolation = cfg.ExtendedInterpolation())
> cp.read(os.path.abspath(os.path.join(root, u'config/sampling.cfg')))

This looks confusing. Are you sure you are reading the right sampling.cfg?

> cp.items('Sampling')
> 
> sampling.cfg contains the following lines:
> [Sampling]
>     nobs = 10
>     nzin = 4
>     nzout = 3
>     ndrops = 1
> 
>     inh = day,loc,z0,value
>     outh = day,loc,sku,value
> 
>     invalran = 1,1e3
>     outvalran = 1,1000
> 
> cp.items(u'Sampling') prints the following:
> [(u'nobs', u'10'),
>  (u'nzin', u'4'),
>  (u'nzout', u'3\nndrops = 1'),
>  (u'inh', u'day,loc,z0,value'),
>  (u'outh', u'day,loc,sku,value'),
>  (u'invalran', u'1,1e3'),
>  (u'outvalran', u'1,1000')]
> 
> ndrops = 1 is not parsed correctly

It looks like the parser does not expand tabs, and your problem may be 
mixing tabs and spaces:

$ cat demo.py
import configparser

data = """\
[Sampling]
\talpha = 1
\tbeta = 2
 \tgamma = 3
\tdelta = 4
"""
print "what you see:"
print data.expandtabs(4)

print "what the parser sees:"
print data.replace("\t", " ")

with open("sampling.cfg", "w") as f:
    f.write(data)

cp = configparser.ConfigParser(
    interpolation=configparser.ExtendedInterpolation()
)
cp.read("sampling.cfg")
for item in cp.items('Sampling'):
    print item
$ python demo.py 
what you see:
[Sampling]
    alpha = 1
    beta = 2
    gamma = 3
    delta = 4

what the parser sees:
[Sampling]
 alpha = 1
 beta = 2
  gamma = 3
 delta = 4

(u'alpha', u'1')
(u'beta', u'2\ngamma = 3')
(u'delta', u'4')
$ 




From alister.ware at ntlworld.com  Wed Jan 25 07:00:25 2017
From: alister.ware at ntlworld.com (alister)
Date: Wed, 25 Jan 2017 12:00:25 GMT
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <o65nbu$mre$1@blaine.gmane.org>
 <CAPTjJmqh_jTGyZ0_v-JELxM--H=b-2azB3aSC5fSq1Hk38CpXQ@mail.gmail.com>
 <mailman.42.1485203128.2473.python-list@python.org>
 <RLthA.146356$c41.2628@fx40.am4>
 <slrno8cqj2.2ca.jon+usenet@sable.unequivocal.eu>
 <%tJhA.371507$1y4.144483@fx20.am4>
 <slrno8ep8b.3j6.jon+usenet@sable.unequivocal.eu>
 <BVKhA.178901$vP3.3591@fx45.am4>
 <4iuf8clgqekpr1jkf9danh99h4eedd5ptb@4ax.com>
 <mailman.78.1485306617.2473.python-list@python.org>
Message-ID: <tr0iA.108543$he2.15794@fx22.am4>

On Tue, 24 Jan 2017 20:09:45 -0500, Dennis Lee Bieber wrote:

> On Tue, 24 Jan 2017 16:03:45 GMT, alister <alister.ware at ntlworld.com>
> declaimed the following:
> 
>>On Tue, 24 Jan 2017 14:28:55 +0000, Jon Ribbens wrote:
>>
>>> On 2017-01-24, alister <alister.ware at ntlworld.com> wrote:
>>>> On Mon, 23 Jan 2017 20:39:26 +0000, Jon Ribbens wrote:
>>>>> That's a meaningless statement. *Everything* is a poison in
>>>>> sufficient quantities.
>>>>
>>>> indees when I here someone saying "I won't have any xyz because they
>>>> have heard that too much is bad for them" I invariably inform them
>>>> that too much oxygen is poisonous & challenge then to cut that out
>>>> completely :-)
>>> 
>>> Just wait until they find out that raw fruit and vegetables contain
>>> hundreds of chemicals!
>>
>>then send them of to one of the sitre relating to Di-Hydrogen
>>Monoxide...
> 
> 	Or: http://vintage.failed-dam.org/tomato.htm
>>
>>I know of one organic food producer that has even tried to deny the use
>>the stuff ;-)
> 
> 	While I'm trying to figure out what significance Centrum vitamins 
have
> with being "non-GMO"... Unless they are implying that other companies
> are using modified bacteria as chemical factories... How many vitamin
> tablets can you think of that are compounded from plant extracts these
> days?

what has centrum vitamins & GMO got to do with di-hydrogen-monoxide?
(although 1000-1 says they use it in their processes somewhere)




-- 
A sequel is an admission that you've been reduced to imitating yourself.
		-- Don Marquis


From this.wiederkehr at gmail.com  Wed Jan 25 07:36:34 2017
From: this.wiederkehr at gmail.com (This Wiederkehr)
Date: Wed, 25 Jan 2017 13:36:34 +0100
Subject: With class as contextmanager
In-Reply-To: <o6922a$di5$1@blaine.gmane.org>
References: <CAB6NXhg6yKKHASr-EUiz2=xvvSBEiNZFj97G5T9-Cgxh_PGtsQ@mail.gmail.com>
 <o6922a$di5$1@blaine.gmane.org>
Message-ID: <CAB6NXhjcSokDfXy6SQq86Mzvd-rsMOsTygQQHayxk5O2K+bKWw@mail.gmail.com>

Thank you for your answers. Very appreciated.

I ended up doing it as follows:

class MetaLock(type):

    def __init__(cls, *args):
        super().__init__(*args)
        cls.lock = Lock()
        cls.instances = []

    def register(cls, instance):
        cls.instances.append(instance)

    def __enter__(cls):
        cls.lock.acquire()


    def __exit__(cls, exc_type, exc_val, exc_tb):
        for instance in cls.instances:
            instance.cleanup()
        cls.instances = []
        cls.lock.release()
        return False


class Klass(metaclass=MetaLock):

    def __init__(self):
        if not self.__class__.lock.locked():
            raise Exception("You have to use the context manager on
the Class Object!")
        self.__class__.register(self)

    def cleaup(self):
        pass

with Klass:
    inst1 = Klass()
    inst2 = Klass()

    # on leaving the context the cleanup of each instance of Klass is called.

Regards

This


2017-01-25 3:21 GMT+01:00 Terry Reedy <tjreedy at udel.edu>:

> On 1/24/2017 4:31 PM, This Wiederkehr wrote:
>
> having a class definition:
>>
>> class Test():
>>
>> @classmethod
>> def __enter__(cls):
>>     pass
>>
>> @classmethod
>> def __exit__(cls, exception_type, execption_value, callback):
>>     pass
>>
>> now using this as a contextmanager does not work, even though Test is an
>> object and has the two required methods __enter__ and __exit__.
>>
>> it fails with:
>> #Attribute Error: __enter__
>>
>>
>> This is not working because behind the scene it does something like:
>> type(Test).__enter__(Test)
>>
>> But isn't this supposed to be working?
>>
>
> No.  Unqualified 'method' means instance method, not class method.
>
> One can simulate instance methods like so:
>
> >>> import types
> >>> def f(self): print('f called')
>
> >>> class C: pass
>
> >>> c = C()
> >>> c.m = types.MethodType(f, c)
> >>> c.m()
> f called
>
> However, this will not work for dunder methods where the lookup for the
> method starts with the class and not the object itself.
>
> >>> def h(self): return 1
>
> >>> c.__hash__ = types.MethodType(h, c)
> >>> hash(c)  # calls type(c).__hash__, not c.__hash__
> -9223371924496369383
>
> --
> Terry Jan Reedy
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>



-- 
This Wiederkehr
Vorgasse 21
5722 Gr?nichen
079 785 70 75


From murphyclara565 at gmail.com  Wed Jan 25 09:15:04 2017
From: murphyclara565 at gmail.com (murphyclara565 at gmail.com)
Date: Wed, 25 Jan 2017 06:15:04 -0800 (PST)
Subject: Python
Message-ID: <277618c7-269d-4c73-bb64-1c83e932f9fd@googlegroups.com>

Need help



From breamoreboy at gmail.com  Wed Jan 25 09:36:05 2017
From: breamoreboy at gmail.com (breamoreboy at gmail.com)
Date: Wed, 25 Jan 2017 06:36:05 -0800 (PST)
Subject: Python
In-Reply-To: <277618c7-269d-4c73-bb64-1c83e932f9fd@googlegroups.com>
References: <277618c7-269d-4c73-bb64-1c83e932f9fd@googlegroups.com>
Message-ID: <ebe696ae-3ec8-4aaa-b139-a20309e88884@googlegroups.com>

On Wednesday, January 25, 2017 at 2:15:16 PM UTC, murphyc... at gmail.com wrote:
> Need help

Please read this http://www.catb.org/~esr/faqs/smart-questions.html and then this http://sscce.org/ before trying again.

Kindest regards.

Mark Lawrence


From Joaquin.Alzola at lebara.com  Wed Jan 25 09:46:46 2017
From: Joaquin.Alzola at lebara.com (Joaquin Alzola)
Date: Wed, 25 Jan 2017 14:46:46 +0000
Subject: Python
In-Reply-To: <277618c7-269d-4c73-bb64-1c83e932f9fd@googlegroups.com>
References: <277618c7-269d-4c73-bb64-1c83e932f9fd@googlegroups.com>
Message-ID: <DB5PR07MB080684D173DD52F2F02086E6F0740@DB5PR07MB0806.eurprd07.prod.outlook.com>



> Need help
I need a beer

Put your question in the mailing list I think you can get the help needed.
This email is confidential and may be subject to privilege. If you are not the intended recipient, please do not copy or disclose its content but contact the sender immediately upon receipt.


From stephane at wirtel.be  Wed Jan 25 09:51:46 2017
From: stephane at wirtel.be (Stephane Wirtel)
Date: Wed, 25 Jan 2017 15:51:46 +0100
Subject: Python
In-Reply-To: <DB5PR07MB080684D173DD52F2F02086E6F0740@DB5PR07MB0806.eurprd07.prod.outlook.com>
References: <277618c7-269d-4c73-bb64-1c83e932f9fd@googlegroups.com>
 <DB5PR07MB080684D173DD52F2F02086E6F0740@DB5PR07MB0806.eurprd07.prod.outlook.com>
Message-ID: <7B46CC65-0EE9-48D0-A303-A1DB0F9C296C@wirtel.be>

Come to PythonFosdem https://www.python-fosdem.org we will offer some beers on 4 & 5 feb in Brussels


> On 25 Jan 2017, at 15:46, Joaquin Alzola <Joaquin.Alzola at lebara.com> wrote:
> 
> 
> 
>> Need help
> I need a beer
> 
> Put your question in the mailing list I think you can get the help needed.
> This email is confidential and may be subject to privilege. If you are not the intended recipient, please do not copy or disclose its content but contact the sender immediately upon receipt.
> -- 
> https://mail.python.org/mailman/listinfo/python-list



From cannedham284 at hotmail.com  Wed Jan 25 10:13:15 2017
From: cannedham284 at hotmail.com (Ben Iannitelli)
Date: Wed, 25 Jan 2017 15:13:15 +0000
Subject: How an editor can help with block nesting (was Re: How coding in
 Python is bad for you)
In-Reply-To: <CAPTjJmoj7Kku8J99HgLXVMhHUvMqmOQA90HZOvmKq-b2-Eq=Vg@mail.gmail.com>
References: <CAPTjJmqthQU7XgrieZgR=7jQPLtdBrjyZ+YERZqfpg2CvVaLLQ@mail.gmail.com>
 <mailman.70.1485292804.2473.python-list@python.org>
 <5887ffe2$0$1603$c3e8da3$5496439d@news.astraweb.com>,
 <CAPTjJmoj7Kku8J99HgLXVMhHUvMqmOQA90HZOvmKq-b2-Eq=Vg@mail.gmail.com>
Message-ID: <MWHPR19MB0975F5109AD102A12896D62496740@MWHPR19MB0975.namprd19.prod.outlook.com>

On Wed, Jan 25, 2017 at 6:31 AM, Ben Bacarisse <ben.usenet at bsb.me.uk><mailto:ben.usenet at bsb.me.uk> wrote:

In Python the editor could, for example, highlight the block you are
typing in, so as soon as you leave the body of the 'if' it would stop
being marked and the containing code would be highlighted.  Just moving
the cursor up and down would show you what block everything is in.  I
don't know if any editors help like this -- that's part of my reason to
ask.
@Ben B.: Have you had a look at Notepad++? When it detects that you're editing a Python file, a ruler on the left-hand margin of the editing window employs a system of boxes and lines to show which blocks of code belong to which conditional clause, with those pertaining to the current block in red.

Below are attempts to sketch it out without the benefit of screenshots or color.
First attempt:
[box with a dash inside of it ]if __name__ == "__main__":
[U+2514]    main()

Second attempt (imagine that your cursor is somewhere in the same line as the "print" statement) :
[box with a dash inside of it, in gray ]def main():
[box with a dash inside of it, in gray ]    with open("some_spreadsheet.csv",newline='') as sheet:
[U+2502, in gray]        data = csv.DictReader(sheet)
[box with a dash inside of it, in RED ]        for n,row in enumerate(data):
[U+2514, in RED]            print(n,row)

I didn't do it justice, but that's honestly the best I can do. If you can find the time to install it and then play with it, you can actually see for yourself whether that feature is loyal to the idea you described.


HTH


-Ben I.


From bkline at rksystems.com  Wed Jan 25 10:16:24 2017
From: bkline at rksystems.com (Bob Kline)
Date: Wed, 25 Jan 2017 07:16:24 -0800 (PST)
Subject: The argparse docs don't say who's responsible for closing FileType
 objects
Message-ID: <c25d32ab-e90e-41d1-9827-ea7f083676f5@googlegroups.com>

The subject line pretty much says it all. Should the programmer close the file? If the programmer does that, and the user has asked that the file object be hooked up to standard in (or standard out) what will happen? If the programmer doesn't close it, does it get closed cleanly in the face of an exception?

Thanks!


From alister.ware at ntlworld.com  Wed Jan 25 10:33:03 2017
From: alister.ware at ntlworld.com (alister)
Date: Wed, 25 Jan 2017 15:33:03 GMT
Subject: The argparse docs don't say who's responsible for closing
 FileType objects
References: <c25d32ab-e90e-41d1-9827-ea7f083676f5@googlegroups.com>
Message-ID: <Py3iA.268394$Ww5.33663@fx42.am4>

On Wed, 25 Jan 2017 07:16:24 -0800, Bob Kline wrote:

> The subject line pretty much says it all. Should the programmer close
> the file? If the programmer does that, and the user has asked that the
> file object be hooked up to standard in (or standard out) what will
> happen? If the programmer doesn't close it, does it get closed cleanly
> in the face of an exception?
> 
> Thanks!

i would think the principle is always the same

if you open a file close it behind you

using "with" should ensure this always happens
 




-- 
It is bad luck to be superstitious.
		-- Andrew W. Mathis


From auriocus at gmx.de  Wed Jan 25 14:12:15 2017
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Wed, 25 Jan 2017 20:12:15 +0100
Subject: Hide text in entry box when i click on it.(GUI using Tkinter in
 python)
In-Reply-To: <mailman.85.1485335951.2473.python-list@python.org>
References: <01419236-7cb8-498e-b3bb-9f209b1db53e@googlegroups.com>
 <o69qhc$h91$1@blaine.gmane.org>
 <mailman.85.1485335951.2473.python-list@python.org>
Message-ID: <o6at7a$s97$1@dont-email.me>

Am 25.01.17 um 10:18 schrieb Peter Otten:
> hmmeeranrizvi18 at gmail.com wrote:
>
>> Hello Guys,
>> Here i am creating a entry box with some text,i need to hide the text when
>> i click on it.

> search.bind("<Button-1>", clear_search)
>

This is the correct answer for a mouse click. The typical use case 
(disappearing placeholder) should also trigger, when somebody uses the 
tab key to set the focus to the window. This can be achieved by binding 
to the <FocusIn> event instead:

	search.bind("<FocusIn>", clear_search)

In addition, repeated clicking does not clear the text then.

	Christian


From rryan.asu at gmail.com  Wed Jan 25 15:37:07 2017
From: rryan.asu at gmail.com (rryan.asu at gmail.com)
Date: Wed, 25 Jan 2017 12:37:07 -0800 (PST)
Subject: PhotoImage.paste
In-Reply-To: <eeqp6eF26ioU1@mid.individual.net>
References: <d0476502-d414-4022-81e6-b28a648ac3ca@googlegroups.com>
 <2c6196b4-89ac-6111-cb13-5062bf538297@mrabarnett.plus.com>
 <mailman.64.1485263317.2473.python-list@python.org>
 <e6f3f915-9bbe-41cf-8594-4a2e6dee9550@googlegroups.com>
 <61vf8c580fkmpm4jr7mmf928tgfmu7bmb4@4ax.com>
 <mailman.79.1485307875.2473.python-list@python.org>
 <eeqp6eF26ioU1@mid.individual.net>
Message-ID: <8da721cb-9813-48f0-9f8c-1380db25ed68@googlegroups.com>

Hi Greg,

Yeah, I thought of that too...  So I was trying to store it as only a grayscale image and use the "L" format.  I wonder if maybe that didn't work?  I'll play around with that and ensure I did what I think I did.  But that's a good reminder.

Thanks!
Russell


On Tuesday, January 24, 2017 at 11:51:37 PM UTC-5, Gregory Ewing wrote:
> Dennis Lee Bieber wrote:
> > 	But practically everything these days uses true/high color, in which
> > each pixel encodes the exact color to be displayed. This means that
> > changing all matching pixels from one given color to another given color
> > requires rewriting those pixels color data.
> 
> Yes, and a 4k x 4k RGBA image is about 64MB of data.
> I'm not surprised it takes a noticeable amount of
> time to change all of that.
> 
> -- 
> Greg


From paul.nospam at rudin.co.uk  Wed Jan 25 17:14:29 2017
From: paul.nospam at rudin.co.uk (Paul Rudin)
Date: Wed, 25 Jan 2017 22:14:29 +0000
Subject: Python
References: <277618c7-269d-4c73-bb64-1c83e932f9fd@googlegroups.com>
 <DB5PR07MB080684D173DD52F2F02086E6F0740@DB5PR07MB0806.eurprd07.prod.outlook.com>
 <mailman.89.1485355609.2473.python-list@python.org>
Message-ID: <87k29iu6re.fsf@rudin.co.uk>

Joaquin Alzola <Joaquin.Alzola at lebara.com> writes:

> This email is confidential and may be subject to privilege. If you are not the
> intended recipient, please do not copy or disclose its content but contact the
> sender immediately upon receipt.

Probably best not to send it to a publicly accessible mailing list
then :/


From none at invalid.com  Wed Jan 25 17:48:42 2017
From: none at invalid.com (mm0fmf)
Date: Wed, 25 Jan 2017 22:48:42 +0000
Subject: Python
In-Reply-To: <277618c7-269d-4c73-bb64-1c83e932f9fd@googlegroups.com>
References: <277618c7-269d-4c73-bb64-1c83e932f9fd@googlegroups.com>
Message-ID: <o6b9t9$d3f$1@dont-email.me>

On 25/01/2017 14:15, murphyclara565 at gmail.com wrote:
> Need help
>
Can help, need money.


From sandeep.nagar at gmail.com  Wed Jan 25 21:25:44 2017
From: sandeep.nagar at gmail.com (Sandeep Nagar)
Date: Wed, 25 Jan 2017 18:25:44 -0800 (PST)
Subject: Need reviews for my book on introductory python
Message-ID: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>

Hi,

A few month ago I wrote a book on introductory python based on my experinces while teaching python to Bachelor students of engineering. It is now available in e-book and paperback format at Amazon. 

https://www.amazon.com/dp/1520153686

The book is written for beginners of python programming language and written in learn-by-doing manner. If some group members can review the same, it will be useful for myself to come up with an improved version.

Other similar books of mine are based on Octave and Scilab with following links:

https://www.amazon.com/dp/152015111X (Scilab)

https://www.amazon.com/dp/1520158106 (Octave)

If you are interested in open source computing, please have a look. 

Also please do share the link for print books with your colleagues at other universities and recommend them for libraries and researchers, if you feel that they can be helpful to them.

Regards

Sandeep


From tonytonytony0724 at gmail.com  Wed Jan 25 21:41:59 2017
From: tonytonytony0724 at gmail.com (Tony Chen)
Date: Wed, 25 Jan 2017 18:41:59 -0800 (PST)
Subject: any one used moviepy please come in!!! I need help, thanks!
In-Reply-To: <mailman.83.1485329629.2473.python-list@python.org>
References: <5ec6d36f-5200-4882-98ce-c317deab35b3@googlegroups.com>
 <CAPTjJmov+oqYy7MHdE=vBBHprCULyPXercYbsO=XAxE+MrE85Q@mail.gmail.com>
 <mailman.83.1485329629.2473.python-list@python.org>
Message-ID: <12117181-ec3b-4dd6-9f58-7b0c81f0ae20@googlegroups.com>

On Wednesday, January 25, 2017 at 8:34:01 PM UTC+13, Chris Angelico wrote:
> On Wed, Jan 25, 2017 at 6:22 PM, Tony Chen <tonytonytony0724 at gmail.com> wrote:
> > This error can be due to the fact that ImageMagick is not installed on your computer, or (for Windows users) that you didn't specify the path to the ImageMagick binary in file conf.py, or.that the path you specified is incorrect
> 
> So... is ImageMagick installed?
> 
> ChrisA

Okay... Yes it's installed. This problem has been solved haha. Thank you for replying.


From cmalliopoulos at gmail.com  Thu Jan 26 07:13:30 2017
From: cmalliopoulos at gmail.com (Christos Malliopoulos)
Date: Thu, 26 Jan 2017 12:13:30 +0000
Subject: configparser bug
In-Reply-To: <o6a29b$li6$1@blaine.gmane.org>
References: <CAMuzKSso0uxFcS8mQbBeY44rAUHy3rwXd4CL6qnMDQXger+7hg@mail.gmail.com>
 <CAMuzKSt+5eV+wefoU6Lf4dHgvph8p9kWw7yiD+qzeKqbMeY4_A@mail.gmail.com>
 <o6a29b$li6$1@blaine.gmane.org>
Message-ID: <CAMuzKStPAeVWVFV_p2mR5-et7JRgH3ok24Uz7JhiEfx6Nt5+Sg@mail.gmail.com>

Thanx Peter for your prompt response.
I replaced tabs with spaces and had no problem reading the file.
I think however it is sth to correct in next versions

BR
Chris


On Wed, Jan 25, 2017 at 1:32 PM Peter Otten <__peter__ at web.de> wrote:

> Christos Malliopoulos wrote:
>
> > Hi,
> >
> > I run Ubuntu 16.04 LTS in a VM using VMWare Workstation on a Windows 10
> > host.
> > apt show python-configparser shows 3.3.0r2-2
> > On python 2.7.12 I use the following code:
> >
> > import configparser as cfg
> > root =
> > u'/'.join(os.path.split(os.path.abspath('cfg.py'))[0].split('/')[:-2])
> > cp = cfg.ConfigParser(interpolation = cfg.ExtendedInterpolation())
> > cp.read(os.path.abspath(os.path.join(root, u'config/sampling.cfg')))
>
> This looks confusing. Are you sure you are reading the right sampling.cfg?
>
> > cp.items('Sampling')
> >
> > sampling.cfg contains the following lines:
> > [Sampling]
> >     nobs = 10
> >     nzin = 4
> >     nzout = 3
> >     ndrops = 1
> >
> >     inh = day,loc,z0,value
> >     outh = day,loc,sku,value
> >
> >     invalran = 1,1e3
> >     outvalran = 1,1000
> >
> > cp.items(u'Sampling') prints the following:
> > [(u'nobs', u'10'),
> >  (u'nzin', u'4'),
> >  (u'nzout', u'3\nndrops = 1'),
> >  (u'inh', u'day,loc,z0,value'),
> >  (u'outh', u'day,loc,sku,value'),
> >  (u'invalran', u'1,1e3'),
> >  (u'outvalran', u'1,1000')]
> >
> > ndrops = 1 is not parsed correctly
>
> It looks like the parser does not expand tabs, and your problem may be
> mixing tabs and spaces:
>
> $ cat demo.py
> import configparser
>
> data = """\
> [Sampling]
> \talpha = 1
> \tbeta = 2
>  \tgamma = 3
> \tdelta = 4
> """
> print "what you see:"
> print data.expandtabs(4)
>
> print "what the parser sees:"
> print data.replace("\t", " ")
>
> with open("sampling.cfg", "w") as f:
>     f.write(data)
>
> cp = configparser.ConfigParser(
>     interpolation=configparser.ExtendedInterpolation()
> )
> cp.read("sampling.cfg")
> for item in cp.items('Sampling'):
>     print item
> $ python demo.py
> what you see:
> [Sampling]
>     alpha = 1
>     beta = 2
>     gamma = 3
>     delta = 4
>
> what the parser sees:
> [Sampling]
>  alpha = 1
>  beta = 2
>   gamma = 3
>  delta = 4
>
> (u'alpha', u'1')
> (u'beta', u'2\ngamma = 3')
> (u'delta', u'4')
> $
>
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>


From tdldev at gmail.com  Thu Jan 26 07:32:17 2017
From: tdldev at gmail.com (Verde Denim)
Date: Thu, 26 Jan 2017 07:32:17 -0500
Subject: Need reviews for my book on introductory python
In-Reply-To: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
References: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
Message-ID: <d4228bb0-4be4-b647-fb9d-f533503511af@gmail.com>

You would like us to volunteer to "review" your book that you'd like us 
to buy from you and that has already been published and used as a 
curriculum guide... If you'd like it reviewed by the Py community, how 
about making it available to us and allow us to edit it or suggest 
changes as needed? This, of course, would be for no-charge as we are 
using our time and resources to review your publication at no  cost to 
you. Thanks.


On 1/25/2017 9:25 PM, Sandeep Nagar wrote:
> Hi,
>
> A few month ago I wrote a book on introductory python based on my experinces while teaching python to Bachelor students of engineering. It is now available in e-book and paperback format at Amazon.
>
> https://www.amazon.com/dp/1520153686
>
> The book is written for beginners of python programming language and written in learn-by-doing manner. If some group members can review the same, it will be useful for myself to come up with an improved version.
>
> Other similar books of mine are based on Octave and Scilab with following links:
>
> https://www.amazon.com/dp/152015111X (Scilab)
>
> https://www.amazon.com/dp/1520158106 (Octave)
>
> If you are interested in open source computing, please have a look.
>
> Also please do share the link for print books with your colleagues at other universities and recommend them for libraries and researchers, if you feel that they can be helpful to them.
>
> Regards
>
> Sandeep


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus



From bc at freeuk.com  Thu Jan 26 08:32:41 2017
From: bc at freeuk.com (BartC)
Date: Thu, 26 Jan 2017 13:32:41 +0000
Subject: Need reviews for my book on introductory python
In-Reply-To: <mailman.93.1485433950.2473.python-list@python.org>
References: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
 <d4228bb0-4be4-b647-fb9d-f533503511af@gmail.com>
 <mailman.93.1485433950.2473.python-list@python.org>
Message-ID: <o6ctml$pnd$1@dont-email.me>

On 26/01/2017 12:32, Verde Denim wrote:
> You would like us to volunteer to "review" your book that you'd like us
> to buy from you and that has already been published and used as a
> curriculum guide... If you'd like it reviewed by the Py community, how
> about making it available to us and allow us to edit it or suggest
> changes as needed?

The amazon link lets you look at the first few pages free of charge.

That might be enough to form an opinion. (The first pages do include a 
Hello World program; unfortunately it's in C not Python!)


-- 
Bartc



From bgailer at gmail.com  Thu Jan 26 18:32:30 2017
From: bgailer at gmail.com (bob gailer)
Date: Thu, 26 Jan 2017 18:32:30 -0500
Subject: Need reviews for my book on introductory python
In-Reply-To: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
References: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
Message-ID: <8115024f-71c7-d526-37d4-65cfae9be207@gmail.com>

On 1/25/2017 9:25 PM, Sandeep Nagar wrote:
> Hi,
>
> A few month ago I wrote a book on introductory python based on my experinces while teaching python to Bachelor students of engineering. It is now available in e-book and paperback format at Amazon.
>
> https://www.amazon.com/dp/1520153686
>
> The book is written for beginners of python programming language and written in learn-by-doing manner. If some group members can review the same, it will be useful for myself to come up with an improved version.
I'd like to review it, but am reluctant to put out money for a copy! How 
about offering a review copy at no charge?
>
> Other similar books of mine are based on Octave and Scilab with following links:
>
> https://www.amazon.com/dp/152015111X (Scilab)
>
> https://www.amazon.com/dp/1520158106 (Octave)
>
> If you are interested in open source computing, please have a look.
>
> Also please do share the link for print books with your colleagues at other universities and recommend them for libraries and researchers, if you feel that they can be helpful to them.
>
> Regards
>
> Sandeep


-- 
Image and video hosting by TinyPic


From bamccaig at gmail.com  Thu Jan 26 23:07:39 2017
From: bamccaig at gmail.com (Brandon McCaig)
Date: Thu, 26 Jan 2017 23:07:39 -0500
Subject: How coding in Python is bad for you
In-Reply-To: <87h94os1a1.fsf@bsb.me.uk>
References: <mailman.53.1485219364.2473.python-list@python.org>
 <o66bjo$oqb$1@dont-email.me>
 <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>
 <mailman.55.1485225529.2473.python-list@python.org>
 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqupVWHHjnRHTPqxYmVjrtS_k7PdJY0JR_J3KjQTV1uXw@mail.gmail.com>
 <mailman.57.1485232893.2473.python-list@python.org>
 <874m0otq02.fsf@bsb.me.uk> <o67vpt$egb$1@dont-email.me>
 <87h94os1a1.fsf@bsb.me.uk>
Message-ID: <20170127040739.GE1362@test-chamber-1.castopulence.org>

On Tue, Jan 24, 2017 at 07:31:18PM +0000, Ben Bacarisse wrote:
> The trouble is that I've been programming for so long that I
> can't remember what it's like to make block and/or indent
> errors.  Obviously I make typos but they don't survive more
> than a few seconds.

Agreed. In very rare circumstances (likely very tired) you might
make such a mistake without catching it, but typically you'll
catch it during testing, and code review is another chance to
catch it. Source control FTW. I think that a lot of these kinds
of problems happen to beginners and the beginners make the most
noise about how it will be a problem. I initially was against
Python's significant white-space, but in hindsight I can see how
it saves a bit of typing and is not necessarily any worse off.

Hell, considering the code that I have seen in the wild it might
even catch some extra errors that become syntax errors! It's not
at all rare for indentation to not match in languages that don't
require it to at least fit a pattern.

I think that an apples to apples comparison of an erroneous
indentation level would be comparing a misplaced brace:

    foo {
        bar;
    }
        baz;

wapz. Was that supposed to be "foo { bar; baz; }" or "foo { bar;
 } baz;" ? That's effectively the same problem that you might
have with Python code. The answer? Hopefully it's obvious when
looking at the code! If it's not, hopefully source control can
tell you. And if you can't be certain, *talk* to somebody.
There's no substitute for communication.

> In Python the editor could, for example, highlight the block
> you are typing in, so as soon as you leave the body of the 'if'
> it would stop being marked and the containing code would be
> highlighted.  Just moving the cursor up and down would show you
> what block everything is in.  I don't know if any editors help
> like this -- that's part of my reason to ask.

That's actually a pretty neat idea. I don't think I've ever
encoutered an editor that does (or if I have, it has either been
too long or so subtle that it doesn't stand out). I think that it
is a pretty good idea though.

I certainly find it useful to highlight matching braces in
editors, but it can be a pain still. I think that highlighting
the entire block could be useful. Though I suppose it might be
too noisy and distract from what matters? Alternatively, you'd
need different levels of indentation to capture nested
indentation. That shouldn't be a problem if people are limiting
their indentation levels though...

Regards,


-- 
Brandon McCaig <bamccaig at gmail.com> <bambams at castopulence.org>
Castopulence Software <https://www.castopulence.org/>
Blog <http://www.bambams.ca/>
perl -E '$_=q{V zrna gur orfg jvgu jung V fnl. }.
q{Vg qbrfa'\''g nyjnlf fbhaq gung jnl.};
tr/A-Ma-mN-Zn-z/N-Zn-zA-Ma-m/;say'

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From bamccaig at gmail.com  Thu Jan 26 23:15:12 2017
From: bamccaig at gmail.com (Brandon McCaig)
Date: Thu, 26 Jan 2017 23:15:12 -0500
Subject: How coding in Python is bad for you
In-Reply-To: <87bmuws0eb.fsf@bsb.me.uk>
References: <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqupVWHHjnRHTPqxYmVjrtS_k7PdJY0JR_J3KjQTV1uXw@mail.gmail.com>
 <mailman.57.1485232893.2473.python-list@python.org>
 <874m0otq02.fsf@bsb.me.uk>
 <CAPTjJmpzcTrhY94oTxSmO+3=4N+-Egp98WnE_vuZf4uvPVfNsg@mail.gmail.com>
 <mailman.66.1485273496.2473.python-list@python.org>
 <87sho8sa26.fsf@bsb.me.uk>
 <CAPTjJmooLxGkrgd=1JuutbgAKoyWQDfcANrF16hOUgwbBq0dRA@mail.gmail.com>
 <mailman.69.1485279014.2473.python-list@python.org>
 <87bmuws0eb.fsf@bsb.me.uk>
Message-ID: <20170127041512.GF1362@test-chamber-1.castopulence.org>

On Tue, Jan 24, 2017 at 07:50:20PM +0000, Ben Bacarisse wrote:
> I suspect that part of the reason these errors occur is
> precisely because they don't matter to the interpreter and
> students are doing a lot of self-easement based on "does it
> work?" tests. 

I cringe when I hear "it works"! In particular, because it's
often followed by "but I don't know how". I can't even count the
number of times I have reviewed code, spotted something
questionable, approached the author about it, and heard "but it
works!" Well if my analysis is correct it shouldn't so one of us
is obviously wrong. Unfortunately, in my experience, they usually
expect the conversation to be over after "but it works"...

Regards,


-- 
Brandon McCaig <bamccaig at gmail.com> <bambams at castopulence.org>
Castopulence Software <https://www.castopulence.org/>
Blog <http://www.bambams.ca/>
perl -E '$_=q{V zrna gur orfg jvgu jung V fnl. }.
q{Vg qbrfa'\''g nyjnlf fbhaq gung jnl.};
tr/A-Ma-mN-Zn-z/N-Zn-zA-Ma-m/;say'

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From bamccaig at gmail.com  Thu Jan 26 23:33:51 2017
From: bamccaig at gmail.com (Brandon McCaig)
Date: Thu, 26 Jan 2017 23:33:51 -0500
Subject: How coding in Python is bad for you
In-Reply-To: <20170124195430.6c7dcafc@bigbox.christie.dr>
References: <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>
 <mailman.55.1485225529.2473.python-list@python.org>
 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqupVWHHjnRHTPqxYmVjrtS_k7PdJY0JR_J3KjQTV1uXw@mail.gmail.com>
 <mailman.57.1485232893.2473.python-list@python.org>
 <o67f3g$g50$1@dont-email.me>
 <588789ef$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <o6842t$uoi$1@dont-email.me>
 <kltf8ctjhg67s3n4dl83u58meg5oueqkqq@4ax.com>
 <20170124195430.6c7dcafc@bigbox.christie.dr>
Message-ID: <20170127043351.GG1362@test-chamber-1.castopulence.org>

On Tue, Jan 24, 2017 at 07:54:30PM -0600, Tim Chase wrote:
> The editor I use (vim) doesn't even require me to re-select the range
> to shift it.  Just using
> 
>   >']
> 
> or
> 
>   <']
> 
> will indent/dedent from the cursor to the line where your paste ended.

(O_O) You learn something every day. Thank you.

I have been using Vim and vi for probably close to a decade by
now, but I still have a lot to learn... But nevertheless hate to
go without for even a few seconds.

Regards,


-- 
Brandon McCaig <bamccaig at gmail.com> <bambams at castopulence.org>
Castopulence Software <https://www.castopulence.org/>
Blog <http://www.bambams.ca/>
perl -E '$_=q{V zrna gur orfg jvgu jung V fnl. }.
q{Vg qbrfa'\''g nyjnlf fbhaq gung jnl.};
tr/A-Ma-mN-Zn-z/N-Zn-zA-Ma-m/;say'

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From Cecil at decebal.nl  Fri Jan 27 05:54:19 2017
From: Cecil at decebal.nl (Cecil Westerhof)
Date: Fri, 27 Jan 2017 11:54:19 +0100
Subject: How coding in Python is bad for you
References: <mailman.53.1485219364.2473.python-list@python.org>
 <o66bjo$oqb$1@dont-email.me>
 <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>
 <mailman.55.1485225529.2473.python-list@python.org>
 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqupVWHHjnRHTPqxYmVjrtS_k7PdJY0JR_J3KjQTV1uXw@mail.gmail.com>
 <mailman.57.1485232893.2473.python-list@python.org>
 <874m0otq02.fsf@bsb.me.uk> <o67vpt$egb$1@dont-email.me>
 <87h94os1a1.fsf@bsb.me.uk>
 <20170127040739.GE1362@test-chamber-1.castopulence.org>
 <mailman.95.1485490069.2473.python-list@python.org>
Message-ID: <87efzo6aec.fsf@Equus.decebal.nl>

On Friday 27 Jan 2017 05:07 CET, Brandon McCaig wrote:

> Hell, considering the code that I have seen in the wild it might
> even catch some extra errors that become syntax errors! It's not
> at all rare for indentation to not match in languages that don't
> require it to at least fit a pattern.

I remember that when I had to amend the code of a certain programmer I
always needed half a day to reformat his code. Because he was very
good in copy/paste, but I could not made head or tail of his code
because of the zig-zag of his code.

That is why I immediately like the indent rule of Python very much.

My only ?problem? was that I used to put debug statement at the
beginning of a line to see immediately what the debug statements
where. But that was a small price to pay. ;-)

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof


From hpj at urpla.net  Fri Jan 27 09:23:53 2017
From: hpj at urpla.net (Hans-Peter Jansen)
Date: Fri, 27 Jan 2017 15:23:53 +0100
Subject: Referencing section name by interpolation in ConfigParser
In-Reply-To: <o69phv$h0v$1@blaine.gmane.org>
References: <4337515.1dgV1QdrqS@xrated> <o69phv$h0v$1@blaine.gmane.org>
Message-ID: <1979405.f8UazQS3Ae@xrated>

On Mittwoch, 25. Januar 2017 10:01:56 Peter Otten wrote:
> Hans-Peter Jansen wrote:
> > I would like to use a interpolated section name, e.g.:
> > 
> > [Section]
> > secref: %{section}s/whatever
> > 
> > should result in:
> >>>> config['Section']['secref']
> > 
> > 'Section/whatever'
> > 
> > Any idea anybody, how to archive this with minimum fuzz?
> 
> If you can live with the existing "basic interpolation", i. e. %(...)s, not
> %{...}s:

Yes, of course.. Sorry for the typo.

> $ cat config.ini
> [Foo]
> secref: %(section)s/whatever
> [Bar]
> secref: %(section)s/whatever
> $ cat demo.py
> import configparser
> 
> 
> class Interpolation(configparser.BasicInterpolation):
>     def before_get(self, parser, section, option, value, defaults):
>         defaults = defaults.copy()
>         defaults["section"] = section
>         return super().before_get(parser, section, option, value, defaults)
> 
> 
> p = configparser.ConfigParser(interpolation=Interpolation())
> p.read("config.ini")
> for section in "Foo", "Bar":
>     print(section, "-->", p[section]["secref"])
> $ python3 demo.py
> Foo --> Foo/whatever
> Bar --> Bar/whatever
> $

Brilliant as usual, thank you, Peter.

This is exactly, what I was after.

Have a nice weekend,
Pete


From nathan.ernst at gmail.com  Fri Jan 27 12:30:03 2017
From: nathan.ernst at gmail.com (Nathan Ernst)
Date: Fri, 27 Jan 2017 11:30:03 -0600
Subject: How coding in Python is bad for you
In-Reply-To: <87efzo6aec.fsf@Equus.decebal.nl>
References: <mailman.53.1485219364.2473.python-list@python.org>
 <o66bjo$oqb$1@dont-email.me>
 <CAPTjJmoo25wOLdx2+WYoYk9yZz-SZ8WQG+5x5NpkptQADrXahA@mail.gmail.com>
 <mailman.55.1485225529.2473.python-list@python.org>
 <5886d675$0$1501$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqupVWHHjnRHTPqxYmVjrtS_k7PdJY0JR_J3KjQTV1uXw@mail.gmail.com>
 <mailman.57.1485232893.2473.python-list@python.org> <874m0otq02.fsf@bsb.me.uk>
 <o67vpt$egb$1@dont-email.me> <87h94os1a1.fsf@bsb.me.uk>
 <20170127040739.GE1362@test-chamber-1.castopulence.org>
 <mailman.95.1485490069.2473.python-list@python.org>
 <87efzo6aec.fsf@Equus.decebal.nl>
Message-ID: <CAPjBxg9wzE0_=GK_kvMHgsC4H0uUXKeJ5ZTGsYSvPti97TAsKw@mail.gmail.com>

I used to manually reformat unfamiliar C++ by hand, if for no other reason
in that it forced me to read the code and somewhat comprehend what was
going on. Now, I've lost my patience and use clang-format, a great & highly
configurable tool. I also use vim for Python & C++ coding, so I also rely
upon the command "gg=G" to reformat the current file (this doesn't do much
in Python, however).

One of the things I like about python is the indentation. It almost forces
(or rather strongly encourages you) to keep functions short & sweet, to do
a single thing in a function, and avoid too deeply nested structures.

I've seen horrible abominations in C++ over the years. In separate
projects, I've seen functions that were, in one case, over 45 printed
pages, another over 65 pages. The nesting level was way too deep. I think
in the worst case there were 8 levels of nested loops. This was problematic
for many reasons. Multiple developers working on this function at the same
time and attempting to merge was a big problem - the diff tool used by
Clearcase (I know, a WTF, in of itself) would get confused and
occassionally omit closing braces. Good luck resolving a compilation error
by a missing brace in a 5000 line function.  As a result of the pain I've
experienced, I try and keep functions small enough to fit on a
half-vertical, half-horizontal screen, with no line-wraps on a 1080p
monitor. (I'm usually working in a terminal half-screen wide and use
vertical splits in vim to see different parts of a file, or different
files).

On Fri, Jan 27, 2017 at 4:54 AM, Cecil Westerhof <Cecil at decebal.nl> wrote:

> On Friday 27 Jan 2017 05:07 CET, Brandon McCaig wrote:
>
> > Hell, considering the code that I have seen in the wild it might
> > even catch some extra errors that become syntax errors! It's not
> > at all rare for indentation to not match in languages that don't
> > require it to at least fit a pattern.
>
> I remember that when I had to amend the code of a certain programmer I
> always needed half a day to reformat his code. Because he was very
> good in copy/paste, but I could not made head or tail of his code
> because of the zig-zag of his code.
>
> That is why I immediately like the indent rule of Python very much.
>
> My only ?problem? was that I used to put debug statement at the
> beginning of a line to see immediately what the debug statements
> where. But that was a small price to pay. ;-)
>
> --
> Cecil Westerhof
> Senior Software Engineer
> LinkedIn: http://www.linkedin.com/in/cecilwesterhof
> --
> https://mail.python.org/mailman/listinfo/python-list
>


From bgailer at gmail.com  Fri Jan 27 15:09:48 2017
From: bgailer at gmail.com (bob gailer)
Date: Fri, 27 Jan 2017 15:09:48 -0500
Subject: Need reviews for my book on introductory python
In-Reply-To: <CALVVunCmaP8+Ran=8kHVuykLGqa10up=EY=yZ80cfQk2NgE8VQ@mail.gmail.com>
References: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
 <8115024f-71c7-d526-37d4-65cfae9be207@gmail.com>
 <CALVVunCmaP8+Ran=8kHVuykLGqa10up=EY=yZ80cfQk2NgE8VQ@mail.gmail.com>
Message-ID: <a2544659-ba7f-3190-6cae-0b19f98b4ce4@gmail.com>

On 1/26/2017 8:05 PM, Sandeep Nagar wrote:
> Hi
>
> As I mentioned, a scaled down version is available for free at 
> bookmuft.Com which can be used to judge in this case.
Maybe I am blind, but I don't see any mention of bookmuft.Co.
>
> Regards
>
> On Jan 27, 2017 05:02, "bob gailer" <bgailer at gmail.com 
> <mailto:bgailer at gmail.com>> wrote:
>
>     On 1/25/2017 9:25 PM, Sandeep Nagar wrote:
>
>         Hi,
>
>         A few month ago I wrote a book on introductory python based on
>         my experinces while teaching python to Bachelor students of
>         engineering. It is now available in e-book and paperback
>         format at Amazon.
>
>         https://www.amazon.com/dp/1520153686
>         <https://www.amazon.com/dp/1520153686>
>
>         The book is written for beginners of python programming
>         language and written in learn-by-doing manner. If some group
>         members can review the same, it will be useful for myself to
>         come up with an improved version.
>
>     I'd like to review it, but am reluctant to put out money for a
>     copy! How about offering a review copy at no charge?
>
>
>         Other similar books of mine are based on Octave and Scilab
>         with following links:
>
>         https://www.amazon.com/dp/152015111X
>         <https://www.amazon.com/dp/152015111X> (Scilab)
>
>         https://www.amazon.com/dp/1520158106
>         <https://www.amazon.com/dp/1520158106> (Octave)
>
>         If you are interested in open source computing, please have a
>         look.
>
>         Also please do share the link for print books with your
>         colleagues at other universities and recommend them for
>         libraries and researchers, if you feel that they can be
>         helpful to them.
>
>         Regards
>
>         Sandeep
>
>
>
>     -- 
>     Image and video hosting by TinyPic
>


-- 
Image and video hosting by TinyPic


From bgailer at gmail.com  Fri Jan 27 15:17:14 2017
From: bgailer at gmail.com (bob gailer)
Date: Fri, 27 Jan 2017 15:17:14 -0500
Subject: Need reviews for my book on introductory python
In-Reply-To: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
References: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
Message-ID: <d9a8d73b-56db-aa3c-00cd-213a9b40088b@gmail.com>

On 1/25/2017 9:25 PM, Sandeep Nagar wrote:
> Hi,
>
> A few month ago I wrote a book on introductory python based on my experinces while teaching python to Bachelor students of engineering. It is now available in e-book and paperback format at Amazon.
>
> https://www.amazon.com/dp/1520153686
>
> The book is written for beginners of python programming language and written in learn-by-doing manner. If some group members can review the same, it will be useful for myself to come up with an improved version.
Who is the publisher of this book?

I just took a look at the pages that can be viewed on Amazon. Many 
reactions. it is hard for me to write this, as it seems it would sound 
harsh, judgemental, unappreciative. But you did ask for a review, and 
this is my honest reaction.

I find it hard to read a book written by a non-native speaker of 
English. I an constantly having to overlook what to me are spelling, 
grammatical and vocabulary errors. I HIGHLY recommend you find an editor 
who can fix these errors.

When I pick up an "Introduction to ....." book I expect to get right 
into the language. History, interpreted vs compiled, examples in C, if 
included at all should go in an appendix.

I think you should be teaching Python 3 rather than 2. I disagree with 
your reasons for sticking with ver 2.
I, as a developer using Python for over 10 years, welcomed ver 3 and now 
use it exclusively.

Last sentence of 2.2 is confusing.

Section 2.3 you need to tell reader how to obtain a python prompt. The 
example is also confusing, since to most python users it looks like:
 >>> 2+4
6

The result of 2+4. does not appear.

sudo apt-get won't work on Windows. Tell the reader that this is how to 
do it in Unix, and show the Windows equivalent.

I would avoid showing from xxx import * as it is likely to cause 
confusion when a module so imported overwrites a built-in.

Bottom of p 23 (sys.sizeof(). How would a python newbie know to import sys?

I will stop here - there are many other issues.

I am, by degree, an engineer. If this were my introduction to python I 
probably would walk away from python, discouraged by how hard it is to 
learn.


From darcy at vex.net  Fri Jan 27 15:48:06 2017
From: darcy at vex.net (D'Arcy Cain)
Date: Fri, 27 Jan 2017 15:48:06 -0500
Subject: Need reviews for my book on introductory python
In-Reply-To: <d9a8d73b-56db-aa3c-00cd-213a9b40088b@gmail.com>
References: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
 <d9a8d73b-56db-aa3c-00cd-213a9b40088b@gmail.com>
Message-ID: <551ac389-a89d-fac3-6b8f-e505fe1789ed@vex.net>

On 2017-01-27 03:17 PM, bob gailer wrote:
> sudo apt-get won't work on Windows. Tell the reader that this is how to
> do it in Unix, and show the Windows equivalent.

Actually it doesn't work on Unix either.  It only works on Linux.

-- 
D'Arcy J.M. Cain
System Administrator, Vex.Net
http://www.Vex.Net/ IM:darcy at Vex.Net
VoIP: sip:darcy at Vex.Net


From jon+usenet at unequivocal.eu  Fri Jan 27 16:06:50 2017
From: jon+usenet at unequivocal.eu (Jon Ribbens)
Date: Fri, 27 Jan 2017 21:06:50 -0000 (UTC)
Subject: Need reviews for my book on introductory python
References: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
 <d9a8d73b-56db-aa3c-00cd-213a9b40088b@gmail.com>
 <551ac389-a89d-fac3-6b8f-e505fe1789ed@vex.net>
 <mailman.107.1485550509.2473.python-list@python.org>
Message-ID: <slrno8ndmf.3j6.jon+usenet@sable.unequivocal.eu>

On 2017-01-27, D'Arcy Cain <darcy at vex.net> wrote:
> On 2017-01-27 03:17 PM, bob gailer wrote:
>> sudo apt-get won't work on Windows. Tell the reader that this is how to
>> do it in Unix, and show the Windows equivalent.
>
> Actually it doesn't work on Unix either.  It only works on Linux.

Actually it doesn't work on Linux either.  It only works on
Debian-derived systems.


From none at invalid.com  Fri Jan 27 16:18:15 2017
From: none at invalid.com (mm0fmf)
Date: Fri, 27 Jan 2017 21:18:15 +0000
Subject: Need reviews for my book on introductory python
In-Reply-To: <mailman.106.1485548244.2473.python-list@python.org>
References: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
 <d9a8d73b-56db-aa3c-00cd-213a9b40088b@gmail.com>
 <mailman.106.1485548244.2473.python-list@python.org>
Message-ID: <o6gdbl$5c0$1@dont-email.me>

On 27/01/2017 20:17, bob gailer wrote:
> On 1/25/2017 9:25 PM, Sandeep Nagar wrote:
>> Hi,
>>
>> A few month ago I wrote a book on introductory python based on my
>> experinces while teaching python to Bachelor students of engineering.
>> It is now available in e-book and paperback format at Amazon.
>>
>> https://www.amazon.com/dp/1520153686
>>
>> The book is written for beginners of python programming language and
>> written in learn-by-doing manner. If some group members can review the
>> same, it will be useful for myself to come up with an improved version.
> Who is the publisher of this book?
>
> I just took a look at the pages that can be viewed on Amazon. Many
> reactions. it is hard for me to write this, as it seems it would sound
> harsh, judgemental, unappreciative. But you did ask for a review, and
> this is my honest reaction.
>
> I find it hard to read a book written by a non-native speaker of
> English. I an constantly having to overlook what to me are spelling,
> grammatical and vocabulary errors. I HIGHLY recommend you find an editor
> who can fix these errors.
>
Snap. I found it impossible to read and never got to the Python parts. 
It is not written in English. Most of the pronouns and conjunctions are 
missing. It looks like it has not been proof-read as words loose 
capitalisation, many are mis-spelt and grammar rules regarding plural 
cases and agreement are just ignored.







From python at mrabarnett.plus.com  Fri Jan 27 16:36:45 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Fri, 27 Jan 2017 21:36:45 +0000
Subject: Need reviews for my book on introductory python
In-Reply-To: <o6gdbl$5c0$1@dont-email.me>
References: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
 <d9a8d73b-56db-aa3c-00cd-213a9b40088b@gmail.com>
 <mailman.106.1485548244.2473.python-list@python.org>
 <o6gdbl$5c0$1@dont-email.me>
Message-ID: <7e57adfc-60f5-1d6c-fb4a-0613e06ab396@mrabarnett.plus.com>

On 2017-01-27 21:18, mm0fmf wrote:
> On 27/01/2017 20:17, bob gailer wrote:
>> On 1/25/2017 9:25 PM, Sandeep Nagar wrote:
>>> Hi,
>>>
>>> A few month ago I wrote a book on introductory python based on my
>>> experinces while teaching python to Bachelor students of engineering.
>>> It is now available in e-book and paperback format at Amazon.
>>>
>>> https://www.amazon.com/dp/1520153686
>>>
>>> The book is written for beginners of python programming language and
>>> written in learn-by-doing manner. If some group members can review the
>>> same, it will be useful for myself to come up with an improved version.
>> Who is the publisher of this book?
>>
>> I just took a look at the pages that can be viewed on Amazon. Many
>> reactions. it is hard for me to write this, as it seems it would sound
>> harsh, judgemental, unappreciative. But you did ask for a review, and
>> this is my honest reaction.
>>
>> I find it hard to read a book written by a non-native speaker of
>> English. I an constantly having to overlook what to me are spelling,
>> grammatical and vocabulary errors. I HIGHLY recommend you find an editor
>> who can fix these errors.
>>
> Snap. I found it impossible to read and never got to the Python parts.
> It is not written in English. Most of the pronouns and conjunctions are
> missing. It looks like it has not been proof-read as words loose
> capitalisation, many are mis-spelt and grammar rules regarding plural
> cases and agreement are just ignored.
>
"loose"? Don't you mean "lose"? (Or possible "lack"?)



From rgacote at appropriatesolutions.com  Fri Jan 27 17:09:54 2017
From: rgacote at appropriatesolutions.com (Ray Cote)
Date: Fri, 27 Jan 2017 17:09:54 -0500
Subject: Need reviews for my book on introductory python
In-Reply-To: <o6gdbl$5c0$1@dont-email.me>
References: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
 <d9a8d73b-56db-aa3c-00cd-213a9b40088b@gmail.com>
 <mailman.106.1485548244.2473.python-list@python.org>
 <o6gdbl$5c0$1@dont-email.me>
Message-ID: <CAG5tnzqi=m40XvxgFaNQzoVdaas=VdSPaxt0wWn0eHhzTYNbmg@mail.gmail.com>

On Fri, Jan 27, 2017 at 4:18 PM, mm0fmf <none at invalid.com> wrote:

> On 27/01/2017 20:17, bob gailer wrote:
>
>> On 1/25/2017 9:25 PM, Sandeep Nagar wrote:
>>
>>> Hi,
>>>
>>> A few month ago I wrote a book on introductory python based on my
>>> experinces while teaching python to Bachelor students of engineering.
>>> It is now available in e-book and paperback format at Amazon.
>>>
>>> https://www.amazon.com/dp/1520153686
>>>
>>> The book is written for beginners of python programming language and
>>> written in learn-by-doing manner. If some group members can review the
>>> same, it will be useful for myself to come up with an improved version.
>>>
>> Who is the publisher of this book?
>>
>> I just took a look at the pages that can be viewed on Amazon. Many
>> reactions. it is hard for me to write this, as it seems it would sound
>> harsh, judgemental, unappreciative. But you did ask for a review, and
>> this is my honest reaction.
>>
>> I find it hard to read a book written by a non-native speaker of
>> English. I an constantly having to overlook what to me are spelling,
>> grammatical and vocabulary errors. I HIGHLY recommend you find an editor
>> who can fix these errors.
>>
>> Snap. I found it impossible to read and never got to the Python parts. It
> is not written in English. Most of the pronouns and conjunctions are
> missing. It looks like it has not been proof-read as words loose
> capitalisation, many are mis-spelt and grammar rules regarding plural cases
> and agreement are just ignored.
>
>
In addition to what other?s have said:
- congrats on taking the time to write a book and put it out for others.
- Introduction to Python section 2.1 starts with C example. Seems out of
place.
- Search inside the book has 0 results for iterator -- how do you do Python
without iterators?
- Two references to generator, but they are random number generator
references.
- Was confused by the switching in and out of numpy usage.
- And yes, Python3 is the way to go. Been writing Python since 1.5 and
about 90% of my new code is Python 3.5.


From python at lucidity.plus.com  Fri Jan 27 18:11:15 2017
From: python at lucidity.plus.com (Erik)
Date: Fri, 27 Jan 2017 23:11:15 +0000
Subject: Need reviews for my book on introductory python
In-Reply-To: <7e57adfc-60f5-1d6c-fb4a-0613e06ab396@mrabarnett.plus.com>
References: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
 <d9a8d73b-56db-aa3c-00cd-213a9b40088b@gmail.com>
 <mailman.106.1485548244.2473.python-list@python.org>
 <o6gdbl$5c0$1@dont-email.me>
 <7e57adfc-60f5-1d6c-fb4a-0613e06ab396@mrabarnett.plus.com>
Message-ID: <a77af380-c9c7-15a1-9e84-e20b7481df94@lucidity.plus.com>

On 27/01/17 21:36, MRAB wrote:
> "loose"? Don't you mean "lose"? (Or possible "lack"?)

Don't you mean 'Or possibly "lack"'?

https://en.wikipedia.org/wiki/Muphry%27s_law ;)

E.



From ian.g.kelly at gmail.com  Fri Jan 27 18:12:14 2017
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 27 Jan 2017 16:12:14 -0700
Subject: Need reviews for my book on introductory python
In-Reply-To: <a2544659-ba7f-3190-6cae-0b19f98b4ce4@gmail.com>
References: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
 <8115024f-71c7-d526-37d4-65cfae9be207@gmail.com>
 <CALVVunCmaP8+Ran=8kHVuykLGqa10up=EY=yZ80cfQk2NgE8VQ@mail.gmail.com>
 <a2544659-ba7f-3190-6cae-0b19f98b4ce4@gmail.com>
Message-ID: <CALwzidnmp642osg2yoeKFLDYeRZeDBJ-YvFLsK6p61tNn=uVkw@mail.gmail.com>

On Jan 27, 2017 2:13 PM, "bob gailer" <bgailer at gmail.com> wrote:

On 1/26/2017 8:05 PM, Sandeep Nagar wrote:

> Hi
>
> As I mentioned, a scaled down version is available for free at
> bookmuft.Com which can be used to judge in this case.
>
Maybe I am blind, but I don't see any mention of bookmuft.Co.


I pulled up the PDF from bookmuft.com (which I also do not see mentioned in
the original post).

2.1 page 15:

"For example, suppose line 5 of a python program has syntax error, in this
case the program will executes all commands till line 4 and will then show
an error."

This is factually incorrect. A program with a syntax error will not be
executed at all.

The description of the Python interpreter is also pretty far from the
truth. The interpreter does not read Python source code one line at a time
as described. The interpreter only reads Python bytecode. At the point that
the interpreter starts reading bytecode, the Python compiler has already
compiled the entire source file into bytecode.

This description only applies to CPython. Other Python implementations may
work differently.

Page 17:

"When the programs compose of hundreds and thousands of lines, a
compilation process will yield a faster result because the object code
needs to be only compiled once and then run directly on microprocessor.
Whereas an interpreted code will check for interpretations each time it
needs to be processed."

Again, it's only Python byte code that is interpreted. The actual Python
source is compiled and does not need to be reprocessed each time a line of
code is executed.

3.2, page 21:

"logical: This type of data stores boolean values True or False boolean
values and can be operated by boolean operators like AND, OR etc."

The type is named "bool", not "logical".

"Most programming languages use the values 1 or 0 for boolean values but
python differs in this approach."

It's not really important, but I disagree with that assessment of "most
programming languages", at least in regard to modern or high-level ones.

3.3, page 22:

"There are four types of numeric data types" (listing int, long, float and
complex)

You left out Decimal and Fraction.

3.3.1: "Python has arbitrary precision for float, long, complex, hence the
limit to length of these numbers is subject to availability of memory"

Uh, no, that's only true for long. A Python float only has the same
precision as a C double. Same for complex but there are two components,
each with the precision of a C double.

3.3.2, page 24:

"The issue with floating point number based arithmetic is that the answer
is an approximation of real number since real numbers are defined for 10 as
their base whereas computer works with numbers where 2 is used as the base."

This is also incorrect. The definition of real numbers has nothing
whatsoever to do with base 10, and there are plenty of real numbers that
still could not be represented exactly even if float used decimal digits
instead of binary digits, and even if it did have arbitrary precision. For
example, 1/3. For another example, pi.

"Above calculation shows that 0.123_2 = 0.135_10."

Say what? First of all, 0.123 isn't even a valid number in binary. The only
digits available in base 2 are 0 and 1. Secondly, even if we ignore that,
the result of 1/2  + 2/2^2 + 3/2^3 = 1.375, not 0.135.

Page 25:

"One can use the decimal module which has a function Decimal() that returns
the number as stored by the computer."

That is not even close to an accurate description. First, Decimal is a
type, not a function. It differs from float in two important respects: one,
it uses a base-ten representation instead of base two; two, it actually
does have arbitrary precision. Also, it does not return the number as
stored by the computer. It's a completely separate implementation of real
numbers.

"As seen above, Decimal(0.123) occupies 72 bits and hence is more accurate
approximation as compared to 0.123 which occupies 24 bits"

Bytes, not bits. But also, Decimal(0.123) is no more accurate an
approximation than 0.123 because you constructed it from 0.123 which is
already an approximation. It's actually the exact same approximation.
Garbage in, garbage out. Decimal("0.123") on the other hand (note the use
of a string rather than a float as the constructor argument) denotes
exactly the real number 0.123.

3.4, page 26:

All of the information in this section about characters and encodings is
specific to strings and does not pertain to sequences generally.

"Python also deal with characters using data type string, list, tuple."

List and tuple have nothing to do with characters.

3.6, page 28:

"Mapping is a scheme of defining data where each element is identified with
a key called ?hash tag?."

I think you mean "hash value". A hash tag is something one uses when
posting on Twitter.

Page 29:

"In example above, we created a dictionary containing two characters a and
b identified by two keys 1 and 10."

In the example given, 'a' and 'b' are the keys and 1 and 10 are the values.

That's about all I have the energy for. These are the most egregious issues
that I've spotted, but there are loads of others that really need the
services of a professional editor. As it stands I wouldn't recommend this
book to anybody.


From ethan at stoneleaf.us  Fri Jan 27 18:26:38 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Fri, 27 Jan 2017 15:26:38 -0800
Subject: Need reviews for my book on introductory python
In-Reply-To: <a77af380-c9c7-15a1-9e84-e20b7481df94@lucidity.plus.com>
References: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
 <d9a8d73b-56db-aa3c-00cd-213a9b40088b@gmail.com>
 <mailman.106.1485548244.2473.python-list@python.org>
 <o6gdbl$5c0$1@dont-email.me>
 <7e57adfc-60f5-1d6c-fb4a-0613e06ab396@mrabarnett.plus.com>
 <a77af380-c9c7-15a1-9e84-e20b7481df94@lucidity.plus.com>
Message-ID: <588BD72E.7030701@stoneleaf.us>

On 01/27/2017 03:11 PM, Erik wrote:
> On 27/01/17 21:36, MRAB wrote:

>> "loose"? Don't you mean "lose"? (Or possible "lack"?)
>
> Don't you mean 'Or possibly "lack"'?

And this is why books should be reviewed and edited /before publishing/.  ;)

--
~Ethan~


From tjreedy at udel.edu  Fri Jan 27 23:01:59 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Fri, 27 Jan 2017 23:01:59 -0500
Subject: Need reviews for my book on introductory python
In-Reply-To: <CALwzidnmp642osg2yoeKFLDYeRZeDBJ-YvFLsK6p61tNn=uVkw@mail.gmail.com>
References: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
 <8115024f-71c7-d526-37d4-65cfae9be207@gmail.com>
 <CALVVunCmaP8+Ran=8kHVuykLGqa10up=EY=yZ80cfQk2NgE8VQ@mail.gmail.com>
 <a2544659-ba7f-3190-6cae-0b19f98b4ce4@gmail.com>
 <CALwzidnmp642osg2yoeKFLDYeRZeDBJ-YvFLsK6p61tNn=uVkw@mail.gmail.com>
Message-ID: <o6h53i$n6e$1@blaine.gmane.org>

On 1/27/2017 6:12 PM, Ian Kelly wrote:
> On Jan 27, 2017 2:13 PM, "bob gailer" <bgailer at gmail.com> wrote:
>
> On 1/26/2017 8:05 PM, Sandeep Nagar wrote:
>
>> Hi
>>
>> As I mentioned, a scaled down version is available for free at
>> bookmuft.Com which can be used to judge in this case.
>>
> Maybe I am blind, but I don't see any mention of bookmuft.Co.
>
>
> I pulled up the PDF from bookmuft.com (which I also do not see mentioned in
> the original post).
>
> 2.1 page 15:
>
> "For example, suppose line 5 of a python program has syntax error, in this
> case the program will executes all commands till line 4 and will then show
> an error."

This is a run-on sentence, which is to say, two sentences.  Change 
'suntax,' to 'syntax.' and 'in' to ' In'.

> This is factually incorrect. A program with a syntax error will not be
> executed at all.
>
> The description of the Python interpreter is also pretty far from the
> truth. The interpreter does not read Python source code one line at a time
> as described. The interpreter only reads Python bytecode. At the point that
> the interpreter starts reading bytecode, the Python compiler has already
> compiled the entire source file into bytecode.
>
> This description only applies to CPython. Other Python implementations may
> work differently.
>
> Page 17:
>
> "When the programs compose of hundreds and thousands of lines, a
> compilation process will yield a faster result because the object code
> needs to be only compiled once and then run directly on microprocessor.
> Whereas an interpreted code will check for interpretations each time it
> needs to be processed."

"When programs are composed of ..."


> Again, it's only Python byte code that is interpreted. The actual Python
> source is compiled and does not need to be reprocessed each time a line of
> code is executed.
>
> 3.2, page 21:
>
> "logical: This type of data stores boolean values True or False boolean
> values and can be operated by boolean operators like AND, OR etc."
>
> The type is named "bool", not "logical".
>
> "Most programming languages use the values 1 or 0 for boolean values but
> python differs in this approach."
>
> It's not really important, but I disagree with that assessment of "most
> programming languages", at least in regard to modern or high-level ones.
>
> 3.3, page 22:
>
> "There are four types of numeric data types" (listing int, long, float and
> complex)

In 3.x, 'int' was delected and 'long' was renamed 'int'.

I strongly suggest that the next version be written for 3.x with 
2.x-only info either deleted or relegated to footnotes (or parenthetical 
notes).


-- 
Terry Jan Reedy



From darcy at vex.net  Fri Jan 27 23:12:59 2017
From: darcy at vex.net (D'Arcy Cain)
Date: Fri, 27 Jan 2017 23:12:59 -0500
Subject: Need reviews for my book on introductory python
In-Reply-To: <o6h53i$n6e$1@blaine.gmane.org>
References: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
 <8115024f-71c7-d526-37d4-65cfae9be207@gmail.com>
 <CALVVunCmaP8+Ran=8kHVuykLGqa10up=EY=yZ80cfQk2NgE8VQ@mail.gmail.com>
 <a2544659-ba7f-3190-6cae-0b19f98b4ce4@gmail.com>
 <CALwzidnmp642osg2yoeKFLDYeRZeDBJ-YvFLsK6p61tNn=uVkw@mail.gmail.com>
 <o6h53i$n6e$1@blaine.gmane.org>
Message-ID: <05b91269-e562-b9a4-147b-f1b9b100f5ab@vex.net>

On 2017-01-27 11:01 PM, Terry Reedy wrote:
> This is a run-on sentence, which is to say, two sentences.  Change
> 'suntax,' to 'syntax.' and 'in' to ' In'.
    ^^^^^^
I can't believe how many typos and grammar errors there are in this 
thread by people correcting typos and grammar.

And please don't say "suntax".  The government hasn't thought of that 
one yet.  Don't give them ideas.

-- 
D'Arcy J.M. Cain
System Administrator, Vex.Net
http://www.Vex.Net/ IM:darcy at Vex.Net
VoIP: sip:darcy at Vex.Net


From rustompmody at gmail.com  Sat Jan 28 00:47:50 2017
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 27 Jan 2017 21:47:50 -0800 (PST)
Subject: Need reviews for my book on introductory python
In-Reply-To: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
References: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
Message-ID: <40a0350b-be77-4826-82c8-174e43c3c067@googlegroups.com>

On Thursday, January 26, 2017 at 7:55:57 AM UTC+5:30, Sandeep Nagar wrote:
> Hi,
> 
> A few month ago I wrote a book on introductory python based on my experinces while teaching python to Bachelor students of engineering. It is now available in e-book and paperback format at Amazon. 
> 
> https://www.amazon.com/dp/1520153686
> 
> The book is written for beginners of python programming language and written in learn-by-doing manner. If some group members can review the same, it will be useful for myself to come up with an improved version.
> 
> Other similar books of mine are based on Octave and Scilab with following links:
> 
> https://www.amazon.com/dp/152015111X (Scilab)
> 
> https://www.amazon.com/dp/1520158106 (Octave)
> 
> If you are interested in open source computing, please have a look. 

Friendly advice: Write a blog instead of, or at least before writing a book
Sure there are disadvantages... which are IMHO minor/unrealistic:
eg YOur intended audience has no access to internet. About as unrealistic as
them not having access to electricity

Advantages
- Very low bar on entry
- Much finer granularity ? one post vs one book
- Much tighter write?feedback?correct cycle: Minor corrections can be just 
edited in/out. Major additions get a new post
- More current medium ?Medium is the message (or massage)!?
- Saves trees

[Personal note: I started blogging on programming related topics a few years ago:
http://blog.languager.org/
Which crossed 50K hits a few months ago.
More gratifying, Ive received comments and thanks from people like Doug 
McIllroy, co-creator of Unix]


From steve+python at pearwood.info  Sat Jan 28 02:35:01 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Sat, 28 Jan 2017 18:35:01 +1100
Subject: Need reviews for my book on introductory python
References: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
 <8115024f-71c7-d526-37d4-65cfae9be207@gmail.com>
 <CALVVunCmaP8+Ran=8kHVuykLGqa10up=EY=yZ80cfQk2NgE8VQ@mail.gmail.com>
 <a2544659-ba7f-3190-6cae-0b19f98b4ce4@gmail.com>
 <CALwzidnmp642osg2yoeKFLDYeRZeDBJ-YvFLsK6p61tNn=uVkw@mail.gmail.com>
 <o6h53i$n6e$1@blaine.gmane.org>
 <05b91269-e562-b9a4-147b-f1b9b100f5ab@vex.net>
 <mailman.114.1485576783.2473.python-list@python.org>
Message-ID: <588c49a7$0$1618$c3e8da3$5496439d@news.astraweb.com>

On Sat, 28 Jan 2017 03:12 pm, D'Arcy Cain wrote:

> I can't believe how many typos and grammar errors there are in this
> thread by people correcting typos and grammar.


That's practically a law of physics: the Iron Law of Nitpicking, better
known as Muphry's Law.

https://en.wikipedia.org/wiki/Muphry's_law



-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From none at invalid.com  Sat Jan 28 02:57:49 2017
From: none at invalid.com (mm0fmf)
Date: Sat, 28 Jan 2017 07:57:49 +0000
Subject: Need reviews for my book on introductory python
In-Reply-To: <mailman.108.1485553015.2473.python-list@python.org>
References: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
 <d9a8d73b-56db-aa3c-00cd-213a9b40088b@gmail.com>
 <mailman.106.1485548244.2473.python-list@python.org>
 <o6gdbl$5c0$1@dont-email.me>
 <7e57adfc-60f5-1d6c-fb4a-0613e06ab396@mrabarnett.plus.com>
 <mailman.108.1485553015.2473.python-list@python.org>
Message-ID: <o6hiqr$tri$1@dont-email.me>

On 27/01/2017 21:36, MRAB wrote:
> On 2017-01-27 21:18, mm0fmf wrote:
>> On 27/01/2017 20:17, bob gailer wrote:
>>> On 1/25/2017 9:25 PM, Sandeep Nagar wrote:
>>>> Hi,
>>>>
>>>> A few month ago I wrote a book on introductory python based on my
>>>> experinces while teaching python to Bachelor students of engineering.
>>>> It is now available in e-book and paperback format at Amazon.
>>>>
>>>> https://www.amazon.com/dp/1520153686
>>>>
>>>> The book is written for beginners of python programming language and
>>>> written in learn-by-doing manner. If some group members can review the
>>>> same, it will be useful for myself to come up with an improved version.
>>> Who is the publisher of this book?
>>>
>>> I just took a look at the pages that can be viewed on Amazon. Many
>>> reactions. it is hard for me to write this, as it seems it would sound
>>> harsh, judgemental, unappreciative. But you did ask for a review, and
>>> this is my honest reaction.
>>>
>>> I find it hard to read a book written by a non-native speaker of
>>> English. I an constantly having to overlook what to me are spelling,
>>> grammatical and vocabulary errors. I HIGHLY recommend you find an editor
>>> who can fix these errors.
>>>
>> Snap. I found it impossible to read and never got to the Python parts.
>> It is not written in English. Most of the pronouns and conjunctions are
>> missing. It looks like it has not been proof-read as words loose
>> capitalisation, many are mis-spelt and grammar rules regarding plural
>> cases and agreement are just ignored.
>>
> "loose"? Don't you mean "lose"? (Or possible "lack"?)
>

My spelling is not brilliant especially when typing live and so you have 
proved why books need proof-reading.

In particular "lose" is what I meant. Python, the name of the language, 
is a proper noun and should be captialised. In the few pages I read, 
Python appears as "python" and "Python", randomly losing the capital 
letter. Lacking capitalisation would suggest to me that some or all 
words are consistently written without the capital letter such as always 
writing "united states of america".



From steve+python at pearwood.info  Sat Jan 28 03:03:42 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Sat, 28 Jan 2017 19:03:42 +1100
Subject: Is shutil.get_terminal_size useless?
Message-ID: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>

shutil.get_terminal_size returns the wrong values when you pipe your output
to another process, even it you do so in a terminal. Consider this script:


import os
import shutil
print('shutil:', shutil.get_terminal_size(fallback=(999, 999)))
print('os:', os.get_terminal_size(0))


That uses two different methods to get the terminal size. If I run that in a
terminal in the normal way, it works fine, returning the correct size for
my terminal:


[steve at ando ~]$ python3.5 test_gts.py
shutil: os.terminal_size(columns=116, lines=29)
os: os.terminal_size(columns=116, lines=29)


But if I pipe the output to something else, the shutil version fails to
determine the correct terminal size, and falls back on the default:


[steve at ando ~]$ python3.5 test_gts.py | cat
shutil: os.terminal_size(columns=999, lines=999)
os: os.terminal_size(columns=116, lines=29)


while the os version gives the correct result.

Is shutil.get_terminal_size useless? When, if ever, should I use it in
preference to the os version? If the shutil version is broken, can it be
fixed?


Thanks to Bernardas Ali?auskas:

http://granitosaurus.rocks/getting-terminal-size.html


-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From rosuav at gmail.com  Sat Jan 28 03:27:20 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 28 Jan 2017 19:27:20 +1100
Subject: Is shutil.get_terminal_size useless?
In-Reply-To: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmqR5G2jUA09RGEFQG-yOhiBikkAFH+MnaZ7UbioB5XYDA@mail.gmail.com>

On Sat, Jan 28, 2017 at 7:03 PM, Steve D'Aprano
<steve+python at pearwood.info> wrote:
> But if I pipe the output to something else, the shutil version fails to
> determine the correct terminal size, and falls back on the default:
>
>
> [steve at ando ~]$ python3.5 test_gts.py | cat
> shutil: os.terminal_size(columns=999, lines=999)
> os: os.terminal_size(columns=116, lines=29)
>
>
> while the os version gives the correct result.

I believe the problem here is your definition of "correct". When you
inquire of the os module, you're asking, at a fairly low level, what
the terminal window is sized to. But when you ask shutil, you're
asking what a shell utility should do. Quite a few programs change in
behaviour when piped into something else (for instance, 'ls' will
often apply colour and columnate its text, but if you pipe it into
grep, you don't want any of that), and shutil is acknowledging that
different effect.

Both are correct answers - to different questions.

ChrisA


From __peter__ at web.de  Sat Jan 28 03:39:57 2017
From: __peter__ at web.de (Peter Otten)
Date: Sat, 28 Jan 2017 09:39:57 +0100
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <o6hlco$dfa$1@blaine.gmane.org>

Steve D'Aprano wrote:

> shutil.get_terminal_size returns the wrong values when you pipe your
> output to another process, even it you do so in a terminal. Consider this
> script:
> 
> 
> import os
> import shutil
> print('shutil:', shutil.get_terminal_size(fallback=(999, 999)))
> print('os:', os.get_terminal_size(0))
> 
> 
> That uses two different methods to get the terminal size. If I run that in
> a terminal in the normal way, it works fine, returning the correct size
> for my terminal:
> 
> 
> [steve at ando ~]$ python3.5 test_gts.py
> shutil: os.terminal_size(columns=116, lines=29)
> os: os.terminal_size(columns=116, lines=29)
> 
> 
> But if I pipe the output to something else, the shutil version fails to
> determine the correct terminal size, and falls back on the default:
> 
> 
> [steve at ando ~]$ python3.5 test_gts.py | cat
> shutil: os.terminal_size(columns=999, lines=999)
> os: os.terminal_size(columns=116, lines=29)
> 
> 
> while the os version gives the correct result.
> 
> Is shutil.get_terminal_size useless? When, if ever, should I use it in
> preference to the os version? If the shutil version is broken, can it be
> fixed?

One potential advantage of shutil.get_terminal_size() is that you can affect 
it with an environment variable:

$ python3 test_gts.py | cat
shutil: os.terminal_size(columns=999, lines=999)
os: os.terminal_size(columns=72, lines=48)

$ COLUMNS=123 python3 test_gts.py | cat
shutil: os.terminal_size(columns=123, lines=999)
os: os.terminal_size(columns=72, lines=48)

I have the line

export LINES COLUMNS

in my .bashrc, so by default I see the physical size:

$ export COLUMNS LINES
$ python3 test_gts.py | cat
shutil: os.terminal_size(columns=72, lines=48)
os: os.terminal_size(columns=72, lines=48)


> Thanks to Bernardas Ali?auskas:
> 
> http://granitosaurus.rocks/getting-terminal-size.html




From hany.amin.mishriky at gmail.com  Sat Jan 28 04:42:38 2017
From: hany.amin.mishriky at gmail.com (hany.amin.mishriky at gmail.com)
Date: Sat, 28 Jan 2017 01:42:38 -0800 (PST)
Subject: GUI
Message-ID: <c3fd460a-1d4e-4879-a7c4-45cb3abb194a@googlegroups.com>

hay , i am new in the coding world,i would like to understand how a python program is communicating with GUI, for example, if i have a code that require the user to enter a value ,then this code will do some calculations and return a value to the user, how to do that?


From steve+python at pearwood.info  Sat Jan 28 05:49:10 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Sat, 28 Jan 2017 21:49:10 +1100
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqR5G2jUA09RGEFQG-yOhiBikkAFH+MnaZ7UbioB5XYDA@mail.gmail.com>
 <mailman.115.1485592048.2473.python-list@python.org>
Message-ID: <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>

On Sat, 28 Jan 2017 07:27 pm, Chris Angelico wrote:

> On Sat, Jan 28, 2017 at 7:03 PM, Steve D'Aprano
> <steve+python at pearwood.info> wrote:
>> But if I pipe the output to something else, the shutil version fails to
>> determine the correct terminal size, and falls back on the default:
>>
>>
>> [steve at ando ~]$ python3.5 test_gts.py | cat
>> shutil: os.terminal_size(columns=999, lines=999)
>> os: os.terminal_size(columns=116, lines=29)
>>
>>
>> while the os version gives the correct result.
> 
> I believe the problem here is your definition of "correct".

That would be the dictionary definition: 

Correct - conformable to truth; not faulty; free from error

:-P


> When you 
> inquire of the os module, you're asking, at a fairly low level, what
> the terminal window is sized to. 

Right: I want to know what the terminal window is sized to.


> But when you ask shutil, you're 
> asking what a shell utility should do. 

No, I'm asking what the terminal window is sized to. That's why the function
is called get_terminal_size(), not what_should_a_shell_utility_do().

What should a shell utility do, under what circumstances? How can any
function answer that?


> Quite a few programs change in 
> behaviour when piped into something else (for instance, 'ls' will
> often apply colour and columnate its text, but if you pipe it into
> grep, you don't want any of that),

Sure, and if I wanted to know if standard output was being piped to
something else, I'd expect to call a function called something like
where_is_std_out_being_piped_to().

The terminal size doesn't change just because I'm piping output to another
process. Using the terminal size as a proxy for "being piped" is sheer
insanity. That would be like calling

    len(some_string)

and expecting it to return None if some_string was all uppercase.


> and shutil is acknowledging that different effect.

Before there can be a *different* effect, there needs to be an *original*
effect, and I have no idea what effects you are referring to. Be precise,
please.

I don't dispute that there are times where a process may wish to change
behaviour when being piped to something else. But that's a red herring: I'm
asking what the terminal size is. I expect to get the terminal size, or
perhaps an exception if there is no terminal, with an *optional* default,
not a mandatory one.

So far it sounds like shutil.get_terminal_size() is broken by design. Can
somebody convince me it isn't?


> Both are correct answers - to different questions.

But I'm only asking one question: what's the terminal size?

It sounds like your answer is just a long, round-about way of saying "Yes,
it's useless. You cannot trust it to return the terminal size, even when
there is a terminal."


I haven't even asked what happens if it is called when there is no
associated terminal... but now I'm afraid that if I do, it will return the
number of CPUs in my computer or something...




-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From steve+python at pearwood.info  Sat Jan 28 06:00:57 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Sat, 28 Jan 2017 22:00:57 +1100
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <o6hlco$dfa$1@blaine.gmane.org>
 <mailman.116.1485592839.2473.python-list@python.org>
Message-ID: <588c79eb$0$1603$c3e8da3$5496439d@news.astraweb.com>

On Sat, 28 Jan 2017 07:39 pm, Peter Otten wrote:

> One potential advantage of shutil.get_terminal_size() is that you can
> affect it with an environment variable:
> 
> $ python3 test_gts.py | cat
> shutil: os.terminal_size(columns=999, lines=999)
> os: os.terminal_size(columns=72, lines=48)
> 
> $ COLUMNS=123 python3 test_gts.py | cat
> shutil: os.terminal_size(columns=123, lines=999)
> os: os.terminal_size(columns=72, lines=48)

Unless your terminal *actually is* 123 columns wide, I don't see that as an
advantage. I see that as "Hey look, we can fool shutil into returning
absolute garbage instead of the terminal size!"

I can already read environment variables using os.getenv() and os.environ,
so this gives me no new functionality.


> I have the line
> 
> export LINES COLUMNS
> 
> in my .bashrc, so by default I see the physical size:
> 
> $ export COLUMNS LINES
> $ python3 test_gts.py | cat
> shutil: os.terminal_size(columns=72, lines=48)
> os: os.terminal_size(columns=72, lines=48)

But what happens if you resize the terminal while the process is running?
Again, the os.get_terminal_size() correctly returns the updated size, while
shutil.get_terminal_size() doesn't.



-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From rosuav at gmail.com  Sat Jan 28 06:50:07 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 28 Jan 2017 22:50:07 +1100
Subject: Is shutil.get_terminal_size useless?
In-Reply-To: <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqR5G2jUA09RGEFQG-yOhiBikkAFH+MnaZ7UbioB5XYDA@mail.gmail.com>
 <mailman.115.1485592048.2473.python-list@python.org>
 <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmrQ6jNht0-V1KAL+Bumbqqm0n_3r8_MySO=p2DJQz5-0A@mail.gmail.com>

On Sat, Jan 28, 2017 at 9:49 PM, Steve D'Aprano
<steve+python at pearwood.info> wrote:
> The terminal size doesn't change just because I'm piping output to another
> process. Using the terminal size as a proxy for "being piped" is sheer
> insanity.

In a sense, there _is no_ terminal size when you're being piped to
another process. Likewise if you're running in some detached
(non-terminal) context, or if you're being run over some remote link
that hasn't transmitted terminal size info, etc, etc, etc, etc. It's
not a proxy for "being piped" - it's that when your output isn't going
to a terminal, asking "what is my terminal size" isn't particularly
productive.

Would you expect that a process started from systemd is told about the
size of the terminal in which you ran "systemctl start servicename"? I
doubt it. Would you expect a cronjob to use the terminal size when you
most recently edited crontab? No. So why should a program that's being
piped into something else automatically assume the size of the other
program's terminal? You might well be a completely background process.

You can still ask the concrete question about terminal size, and
that's in the 'os' module. The 'shutil' module also looks at
environment variables, and probably would be the place to respond to
TELNET NAWS if that has any sort of primary-level support.

ChrisA


From eryksun at gmail.com  Sat Jan 28 07:09:53 2017
From: eryksun at gmail.com (eryk sun)
Date: Sat, 28 Jan 2017 12:09:53 +0000
Subject: Is shutil.get_terminal_size useless?
In-Reply-To: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CACL+1auaAE0FRGz6KcPM5F1v1sMrm8Ria8GgP6HdqCAzKNB7cw@mail.gmail.com>

On Sat, Jan 28, 2017 at 8:03 AM, Steve D'Aprano
<steve+python at pearwood.info> wrote:
> print('shutil:', shutil.get_terminal_size(fallback=(999, 999)))
> print('os:', os.get_terminal_size(0))
[snip]
> But if I pipe the output to something else, the shutil version fails to
> determine the correct terminal size, and falls back on the default:

The high-level shutil wrapper uses sys.__stdout__, without falling
back on sys.__stdin__ or sys.__stderr__, so it has to rely on the
environment variables and/or fallback value when stdout isn't a
terminal. OTOH, in this case you're calling os.get_terminal_size(0) on
the STDIN file descriptor, which obviously works -- at least on Unix
-- because it's a tty. On Windows that generally won't work because
getting the screen size requires a handle for a screen buffer, not an
input buffer. In this case, os.get_terminal_size(2) would generally
work on Windows because stderr hasn't been redirected.

I just wrote an extended version of shutil.get_terminal_size that
tries six (minus two) ways to Sunday to get the terminal size,
starting with /dev/tty on Unix and CONOUT$ on Windows. It's needlessly
complicated by the Windows implementation of os.get_terminal_size,
which is strangely hard coded. os.get_terminal_size calls GetStdHandle
with a fake mapping of 0, 1, and 2 to the standard handles. It should
just call get_osfhandle on the given file descriptor. That way someone
could use something like the following:

    with open('CONOUT$', 'r+') as conout:
        size = os.get_terminal_size(conout.fileno())

which would be guaranteed to work if the process is attached to a
console. The current implementation forces one to temporarily modify a
standard handle, which has to be gated by a lock for thread safety.


From PointedEars at web.de  Sat Jan 28 07:49:52 2017
From: PointedEars at web.de (Thomas 'PointedEars' Lahn)
Date: Sat, 28 Jan 2017 13:49:52 +0100
Subject: Reviews of book on introductory Python (was: Need reviews for my book
 on introductory python)
References: <d190da0b-de47-4e80-86d1-4142dad85b8c@googlegroups.com>
 <d9a8d73b-56db-aa3c-00cd-213a9b40088b@gmail.com>
 <mailman.106.1485548244.2473.python-list@python.org>
 <o6gdbl$5c0$1@dont-email.me>
 <7e57adfc-60f5-1d6c-fb4a-0613e06ab396@mrabarnett.plus.com>
 <mailman.108.1485553015.2473.python-list@python.org>
 <o6hiqr$tri$1@dont-email.me>
Message-ID: <2259315.Lt9SDvczpP@PointedEars.de>

mm0fmf wrote:

> [?] Python, the name of the language, is a proper noun and should be
> captialised. In the few pages I read, Python appears as "python" and
> "Python", randomly losing the capital letter. Lacking capitalisation
> would suggest to me that some or all words are consistently written
> without the capital letter such as always writing "united states of
> america".

I have not read the book, but it should be noted that lack of capitalisation 
can be intentional.   For example, ?Python? would refer to the programming 
language, while ?python? would refer to the command/program with which the 
language compiler/interpreter is executed.  The latter can appear in prose 
as well, and should, by contrast to the former, be set in a monospace type.

If it is truly capitalised randomly, though, as indicated by the OP?s 
Subject header field value (until before now repeated by everyone else), 
then it is of course badly written.

-- 
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.


From __peter__ at web.de  Sat Jan 28 07:53:55 2017
From: __peter__ at web.de (Peter Otten)
Date: Sat, 28 Jan 2017 13:53:55 +0100
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <o6hlco$dfa$1@blaine.gmane.org>
 <mailman.116.1485592839.2473.python-list@python.org>
 <588c79eb$0$1603$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <o6i498$9m5$1@blaine.gmane.org>

Steve D'Aprano wrote:

>> One potential advantage of shutil.get_terminal_size() is that you can
>> affect it with an environment variable:
>>
>> $ python3 test_gts.py | cat
>> shutil: os.terminal_size(columns=999, lines=999)
>> os: os.terminal_size(columns=72, lines=48)
>>
>> $ COLUMNS=123 python3 test_gts.py | cat
>> shutil: os.terminal_size(columns=123, lines=999)
>> os: os.terminal_size(columns=72, lines=48)
> 
> Unless your terminal *actually is* 123 columns wide, I don't see that as
> an advantage. 

But the script does not write to the terminal and has no way (?) of knowing 
whether the pipe ends in the terminal or in a file.

Assuming it does end in the terminal seems like a good default to me, and 
setting COLUMNS provides a uniform way to override that default.

I prefer that to what e. g. aptitude does which uses the full width of the 
terminal window but falls back to 80

$ aptitude search foo
p   bygfoot                      - Fu?ball-Managerspiel                 
...

$ aptitude search foo | grep python
p   python-foolscap                 - RPC-System auf Basis der 
Objektf?higkeiten
p   python-rfoo                     - Fast RPC package for Python (and a

To get back well-behaved output you need both the envvar and a commandline 
option:

$ aptitude search -w $COLUMNS foo | grep python
p   python-foolscap              - RPC-System auf Basis der Objektf?higk

> I see that as "Hey look, we can fool shutil into returning
> absolute garbage instead of the terminal size!"

There are valid reasons for temporarily altering the number of columns, like 
writing to a file or preparing a code sample.

> I can already read environment variables using os.getenv() and os.environ,
> so this gives me no new functionality.
 
shutil.get_terminal_size()

combines access to shell variables and the os, and IMHO that is a useful 
approach.



From __peter__ at web.de  Sat Jan 28 08:58:54 2017
From: __peter__ at web.de (Peter Otten)
Date: Sat, 28 Jan 2017 14:58:54 +0100
Subject: GUI
References: <c3fd460a-1d4e-4879-a7c4-45cb3abb194a@googlegroups.com>
Message-ID: <o6i82q$4ip$1@blaine.gmane.org>

hany.amin.mishriky at gmail.com wrote:

> hay , i am new in the coding world,i would like to understand how a python
> program is communicating with GUI, for example, if i have a code that
> require the user to enter a value ,then this code will do some
> calculations and return a value to the user, how to do that?

A command line script adding two numbers will look like this:

x = input_int("Enter x:")
y = input_int("Enter y:")
print("x + y =", x + y)

This script will not continue to ask for y until the user has entered the 
value for x

In a GUI you have to provide widgets that allow the user to interact with 
the GUI . Let's assume make_widget() creates an entry widget and shows it in 
a window. Then we can create the part of the GUI where the user enters the x 
and y value with:

entry_x = make_widget()
entry_y = make_widget()

Now we need one more widget to show the result:

entry_sum = make_widget()

We also need a function that recalculates the contents of entry_sum whenever 
the user changes x or y:

def recalculate_sum():
    x = int(entry_x.get_value())
    y = int(entry_y.get_value())
    entry_sum.set_value(sigma)

But when should this function run? We have to connect it to the widgets on 
whose changes it should react. Such a function is called "callback":

# assume that every time the contents of entry_x/y change it calls
# self.on_change()
entry_x.on_change = recalculate_sum
entry_y.on_change = recalculate_sum

Finally you enter an infinite loop that waits for and handles GUI events, 
the most interesting being user activities like typing a digit into one of 
your widgets.

run_event_loop()

There a many GUIs, but they all tend to work in a way similar to the one 
sketched above. Here's a translation of the above pseudo-code to tkinter:

import tkinter as tk

def make_entry(caption, row):
    """Create a Label and an Entry.
    Return the StringVar associated with the Entry.
    """
    # the text displayed to the left of the Entry
    label = tk.Label(root, text=caption)
    label.grid(row=row, column=0)

    var = tk.StringVar() # holds the text entered into the Entry
    entry = tk.Entry(root, textvariable=var)
    entry.grid(row=row, column=1, sticky=tk.EW)
    return var

def calculate_sum(*args):
    """Callback invoked on changes of x or y

    The GUI passes some arguments (*args) that we are not interested in.
    """
    try:
        x = int(var_x.get())
        y = int(var_y.get())
        sigma = x + y
    except ValueError as err:
        # if x or y aren't valid integers
        # show an error message instead of the sum
        sigma = err
    var_sum.set(sigma)

# Create the main window
root = tk.Tk()

# Have the second column take all extra space
root.columnconfigure(1, weight=1)

var_x = make_entry("x", 0)
var_y = make_entry("y", 1)
var_sum = make_entry("x + y =", 2)

# Tell the GUI to invoke calculate_sum() after every change of x or y
var_x.trace("w", calculate_sum)
var_y.trace("w", calculate_sum)

root.mainloop()




From laurent.pointal at free.fr  Sat Jan 28 10:32:05 2017
From: laurent.pointal at free.fr (Laurent Pointal)
Date: 28 Jan 2017 15:32:05 GMT
Subject: Update to Python 3 Cheat Sheet
Message-ID: <588cb975$0$4274$426a74cc@news.free.fr>

Hi,

I updated the cheat sheet on the aesthetic side. Parts bloc and their 
title are now more easily identified with colors (but its nice with B&W 
printing too).
French and german versions have also been updated.

See https://perso.limsi.fr/pointal/python:memento

A+
L.Pointal.


From grant.b.edwards at gmail.com  Sat Jan 28 11:01:03 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Sat, 28 Jan 2017 16:01:03 +0000 (UTC)
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqR5G2jUA09RGEFQG-yOhiBikkAFH+MnaZ7UbioB5XYDA@mail.gmail.com>
 <mailman.115.1485592048.2473.python-list@python.org>
 <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <o6if7v$a97$1@blaine.gmane.org>

On 2017-01-28, Steve D'Aprano <steve+python at pearwood.info> wrote:

> Right: I want to know what the terminal window is sized to.

What do you mean by "the terminal"?

Do you mean the device to which the program's output is connected?
Since output is what you have control over, and what's width you might
want to change, that's what makes sense to me.

Or do you mean the device to which the program's input is connected?

Or do you mean the controlling tty for the process group in which the
program is running?

> The terminal size doesn't change just because I'm piping output to
> another process. Using the terminal size as a proxy for "being
> piped" is sheer insanity.

Why do you want to know what the terminal width is if it isn't to
control the format of the output?  That's why _I_ would want to know
the terminal width.  And in that case, the width of there stdout is
going is what makes the most sense to me.

> But I'm only asking one question: what's the terminal size?

The library call you're making defines "the terminal" as the device to
which stdout is connected.  You apparently which to define "the
terminal" differently.  In which case you need to use a different
library call.

--
Grant




From torriem at gmail.com  Sat Jan 28 11:03:22 2017
From: torriem at gmail.com (Michael Torrie)
Date: Sat, 28 Jan 2017 09:03:22 -0700
Subject: Is shutil.get_terminal_size useless?
In-Reply-To: <588c79eb$0$1603$c3e8da3$5496439d@news.astraweb.com>
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <o6hlco$dfa$1@blaine.gmane.org>
 <mailman.116.1485592839.2473.python-list@python.org>
 <588c79eb$0$1603$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <8a850620-86b9-55c3-6516-624b520f81a3@gmail.com>

On 01/28/2017 04:00 AM, Steve D'Aprano wrote:
>> $ COLUMNS=123 python3 test_gts.py | cat
>> shutil: os.terminal_size(columns=123, lines=999)
>> os: os.terminal_size(columns=72, lines=48)

Interesting. On my machine with Python 3.4, calling
os.get_terminal_size() and piping the output results in the exception
OSError: [Errno 25] Inappropriate ioctl for device

Which is what I'd expect, seeing as there's no tty and no terminal
emulator. I'm not sure why you're not seeing that error also.

> Unless your terminal *actually is* 123 columns wide, I don't see that as an
> advantage. I see that as "Hey look, we can fool shutil into returning
> absolute garbage instead of the terminal size!"

Influencing the column width used by a program for output is very useful
and is often used in shell scripting and piping data.  This allows
programs to just have to use one mechanism to determine line length,
regardless of whether it's running on a tty or connected to a pipe.

> I can already read environment variables using os.getenv() and os.environ,
> so this gives me no new functionality.

Sure but working through shutils provides a uniform way of getting the
maximum column width.  Furthermore using shutils is probably more portable.

I'm not sure if you can override LINES or not, but even if you can't
that's pointless.

> But what happens if you resize the terminal while the process is running?
> Again, the os.get_terminal_size() correctly returns the updated size, while
> shutil.get_terminal_size() doesn't.

For a program that's communicating with a tty, you just have to call
shutil.get_terminal_size() again to get the updated size.

For your piped process, the question doesn't make sense.  You can't
resize a pipe.  The only process that can respond to terminal changes is
the final process in your chain that's actually writing to the tty.

If your process is talking to a pipe, then the only thing you can do is
make an arbitrary decision about the line length (columns==999 means
unlimited, otherwise limit to columns).  Nothing else makes sense.


From steve+python at pearwood.info  Sat Jan 28 11:15:25 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Sun, 29 Jan 2017 03:15:25 +1100
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqR5G2jUA09RGEFQG-yOhiBikkAFH+MnaZ7UbioB5XYDA@mail.gmail.com>
 <mailman.115.1485592048.2473.python-list@python.org>
 <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmrQ6jNht0-V1KAL+Bumbqqm0n_3r8_MySO=p2DJQz5-0A@mail.gmail.com>
 <mailman.117.1485604215.2473.python-list@python.org>
Message-ID: <588cc39f$0$1609$c3e8da3$5496439d@news.astraweb.com>

On Sat, 28 Jan 2017 10:50 pm, Chris Angelico wrote:

> On Sat, Jan 28, 2017 at 9:49 PM, Steve D'Aprano
> <steve+python at pearwood.info> wrote:
>> The terminal size doesn't change just because I'm piping output to
>> another process. Using the terminal size as a proxy for "being piped" is
>> sheer insanity.
> 
> In a sense, there _is no_ terminal size when you're being piped to
> another process. 

In which sense, and why do you think it is relevant?

There clearly is a terminal, because that's where I'm running the code.
Regardless of whether I pipe it to grep or cat or something else, the
output from *that* process still ends up in the same terminal that I typed
the command in.

I acknowledge that there are cases where there is no terminal. As you say:

> Likewise if you're running in some detached 
> (non-terminal) context, 

Then get_terminal_size() should raise, unless you explicitly ask for a
default size.

Likewise:

> or if you're being run over some remote link 
> that hasn't transmitted terminal size info, 

I think that the possibility of having such a remote link is a failure of
the remote protocol being used. (ssh? telnet?) But it is what it is.
Perhaps there genuinely are circumstances where the terminal size exists
but is unknowable -- but the example code isn't one of them.


> etc, etc, etc, etc. It's 
> not a proxy for "being piped" - it's that when your output isn't going
> to a terminal, asking "what is my terminal size" isn't particularly
> productive.

Then explain why os.get_terminal_size() returns the correct answer.

The output might not be going to a terminal (not directly at least) but the
question isn't "what's the size of the terminal that output is going to".
The question is "what's the size of the terminal that this process is
running in", and that has an answer regardless of where output is piped.


> Would you expect that a process started from systemd is told about the
> size of the terminal in which you ran "systemctl start servicename"? I
> doubt it. 

I wouldn't make any assumptions at all about what systemd does. For all I
know, it hard codes a size of (300, 100) into every single process because
that's the size of terminals on Lennart's laptop.


> Would you expect a cronjob to use the terminal size when you 
> most recently edited crontab? No. 

Of course not -- the terminal where you edited crontab is not where the
process is running. Why would it be the least bit relevant?


> So why should a program that's being 
> piped into something else automatically assume the size of the other
> program's terminal? 

Because the other program is running in the same terminal as the first
process.

grep foo * | wc -l

Both grep and wc are running in the same terminal. (Assuming there is any
terminal at all.)


> You might well be a completely background process. 

And if that background process is running in a terminal? What's your point?

I'm not disputing that there are processes where no terminal exists at all.
That's a red herring. os.get_terminal_size() returns the correct result.
Why doesn't shutil?


> You can still ask the concrete question about terminal size, 

You mean like a function called get_terminal_size()?


> and that's in the 'os' module. The 'shutil' module also looks at
> environment variables, 

Why? We already have ways to look at environment variables.

The only complication here is that, perhaps, there may be more than one set
of environment variables to compare, and some order that they should be
preferred. It is often the Unix way that there might be two, or twenty-two
*wink* different environment variables to communicate this information. But
in this case, I'm not able to find anything other than the two standard
variables, COLUMNS and LINES.

Aside: technically these are shell variables, and they may not exist in
arbitrary shells. They also need to be explicitly exported as environment
variables to become visible to Python. See this StackOverflow question for
more information:

http://unix.stackexchange.com/questions/215584/whats-the-name-of-the-environment-variable-with-current-terminal-width



-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From torriem at gmail.com  Sat Jan 28 11:22:24 2017
From: torriem at gmail.com (Michael Torrie)
Date: Sat, 28 Jan 2017 09:22:24 -0700
Subject: Is shutil.get_terminal_size useless?
In-Reply-To: <8a850620-86b9-55c3-6516-624b520f81a3@gmail.com>
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <o6hlco$dfa$1@blaine.gmane.org>
 <mailman.116.1485592839.2473.python-list@python.org>
 <588c79eb$0$1603$c3e8da3$5496439d@news.astraweb.com>
 <8a850620-86b9-55c3-6516-624b520f81a3@gmail.com>
Message-ID: <8a02131b-fc7d-2039-3e34-aaaeb24210cc@gmail.com>

On 01/28/2017 09:03 AM, Michael Torrie wrote:
> On 01/28/2017 04:00 AM, Steve D'Aprano wrote:
>>> $ COLUMNS=123 python3 test_gts.py | cat
>>> shutil: os.terminal_size(columns=123, lines=999)
>>> os: os.terminal_size(columns=72, lines=48)
> 
> Interesting. On my machine with Python 3.4, calling
> os.get_terminal_size() and piping the output results in the exception
> OSError: [Errno 25] Inappropriate ioctl for device

Oh I see you are calling get_terminal_size() on file handle 0 which is
standard in.  Generally, I can't think of very many use cases for caring
about the terminal size on the *input* side. Most times I only care
about the output side, which if it's a pipe doesn't make a lot of sense
to care about, other than maximum line length.


From torriem at gmail.com  Sat Jan 28 11:29:42 2017
From: torriem at gmail.com (Michael Torrie)
Date: Sat, 28 Jan 2017 09:29:42 -0700
Subject: Is shutil.get_terminal_size useless?
In-Reply-To: <588cc39f$0$1609$c3e8da3$5496439d@news.astraweb.com>
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqR5G2jUA09RGEFQG-yOhiBikkAFH+MnaZ7UbioB5XYDA@mail.gmail.com>
 <mailman.115.1485592048.2473.python-list@python.org>
 <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmrQ6jNht0-V1KAL+Bumbqqm0n_3r8_MySO=p2DJQz5-0A@mail.gmail.com>
 <mailman.117.1485604215.2473.python-list@python.org>
 <588cc39f$0$1609$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <4363a1c3-1944-da2c-7993-58c41c66f778@gmail.com>

On 01/28/2017 09:15 AM, Steve D'Aprano wrote:
> Then get_terminal_size() should raise, unless you explicitly ask for a
> default size.

Which it does if you call it on the standard out file handle, which is
the default, and for most applications, the most useful.




From torriem at gmail.com  Sat Jan 28 11:44:54 2017
From: torriem at gmail.com (Michael Torrie)
Date: Sat, 28 Jan 2017 09:44:54 -0700
Subject: Is shutil.get_terminal_size useless?
In-Reply-To: <588cc39f$0$1609$c3e8da3$5496439d@news.astraweb.com>
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqR5G2jUA09RGEFQG-yOhiBikkAFH+MnaZ7UbioB5XYDA@mail.gmail.com>
 <mailman.115.1485592048.2473.python-list@python.org>
 <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmrQ6jNht0-V1KAL+Bumbqqm0n_3r8_MySO=p2DJQz5-0A@mail.gmail.com>
 <mailman.117.1485604215.2473.python-list@python.org>
 <588cc39f$0$1609$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <52029266-5e1d-be47-56b6-240567bf0524@gmail.com>

On 01/28/2017 09:15 AM, Steve D'Aprano wrote:
> Then explain why os.get_terminal_size() returns the correct answer.

Basically you were asking two different questions there.
shutil.get_terminal_size always asks the question of size of the
terminal that the standard output file handle is connected to.  Whereas,
if I read this correctly, you asked os.get_terminal_size to query the
size of the terminal attached to the *standard input* file handle. These
are very different things.  If you want to know the size of the terminal
on the input side, use os.get_terminal_size(0), not shutil.

By the way my comment about raising an exception a moment ago was about
os.get_terminal_size(1).  Apparently shutil is trying to be a
convenience function and lets you specify a default size if there is no
size to determine.

> The output might not be going to a terminal (not directly at least) but the
> question isn't "what's the size of the terminal that output is going to".
> The question is "what's the size of the terminal that this process is
> running in", and that has an answer regardless of where output is piped.

In your specific case, the answer is to get the terminal size by
querying os.get_terminal_size on standard in, since your standard out is
not a tty.

In most other situations the question doesn't make a lot of sense
because there's no correlation between the terminal that the process is
running in and the terminal the process's output is going to be piped to
when a tty is not involved.  For example:

command1 | python3 test_gts.py | command2

In that case your process has no terminal on either end.  Only command1
and command 2 do.



From grant.b.edwards at gmail.com  Sat Jan 28 12:53:11 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Sat, 28 Jan 2017 17:53:11 +0000 (UTC)
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqR5G2jUA09RGEFQG-yOhiBikkAFH+MnaZ7UbioB5XYDA@mail.gmail.com>
 <mailman.115.1485592048.2473.python-list@python.org>
 <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmrQ6jNht0-V1KAL+Bumbqqm0n_3r8_MySO=p2DJQz5-0A@mail.gmail.com>
 <mailman.117.1485604215.2473.python-list@python.org>
 <588cc39f$0$1609$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <o6ilq7$m3s$1@blaine.gmane.org>

On 2017-01-28, Steve D'Aprano <steve+python at pearwood.info> wrote:
> On Sat, 28 Jan 2017 10:50 pm, Chris Angelico wrote:
>
>> On Sat, Jan 28, 2017 at 9:49 PM, Steve D'Aprano
>> <steve+python at pearwood.info> wrote:
>>> The terminal size doesn't change just because I'm piping output to
>>> another process. Using the terminal size as a proxy for "being piped" is
>>> sheer insanity.
>> 
>> In a sense, there _is no_ terminal size when you're being piped to
>> another process. 
>
> In which sense, and why do you think it is relevant?
>
> There clearly is a terminal, because that's where I'm running the
> code.  Regardless of whether I pipe it to grep or cat or something
> else, the output from *that* process still ends up in the same
> terminal that I typed the command in.

I'm sorry, it's not at all obvious to me (or, apparently to the author
of shutil.get_terminal_size) that the output is going to end up in the
terminal where you typed the command.  The output might just as easily
end up in a file or in a completely different terminal (possibly on a
different machine).

> I acknowledge that there are cases where there is no terminal.

And cases where there is a different terminal entirely.

To me, the current behavior of shutil.get_terminal_size seems to be
the most useful.

--
Grant



From rosuav at gmail.com  Sat Jan 28 12:58:36 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 29 Jan 2017 04:58:36 +1100
Subject: Is shutil.get_terminal_size useless?
In-Reply-To: <588cc39f$0$1609$c3e8da3$5496439d@news.astraweb.com>
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqR5G2jUA09RGEFQG-yOhiBikkAFH+MnaZ7UbioB5XYDA@mail.gmail.com>
 <mailman.115.1485592048.2473.python-list@python.org>
 <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmrQ6jNht0-V1KAL+Bumbqqm0n_3r8_MySO=p2DJQz5-0A@mail.gmail.com>
 <mailman.117.1485604215.2473.python-list@python.org>
 <588cc39f$0$1609$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmq6JgDcHQ+3YgWizeUa292+vOzRs6TB=n-chD8Q7f2STA@mail.gmail.com>

On Sun, Jan 29, 2017 at 3:15 AM, Steve D'Aprano
<steve+python at pearwood.info> wrote:
> On Sat, 28 Jan 2017 10:50 pm, Chris Angelico wrote:
>
>> On Sat, Jan 28, 2017 at 9:49 PM, Steve D'Aprano
>> <steve+python at pearwood.info> wrote:
>>> The terminal size doesn't change just because I'm piping output to
>>> another process. Using the terminal size as a proxy for "being piped" is
>>> sheer insanity.
>>
>> In a sense, there _is no_ terminal size when you're being piped to
>> another process.
>
> In which sense, and why do you think it is relevant?
>
> There clearly is a terminal, because that's where I'm running the code.
> Regardless of whether I pipe it to grep or cat or something else, the
> output from *that* process still ends up in the same terminal that I typed
> the command in.

No, not automatically. I've written plenty of programs that accept
input via a pipe and don't display any of it. Just because someone
types "command1 | command2", you can't assume that the terminal
command2 is outputting to is the same size as the one command1 should
be outputting to.

>> etc, etc, etc, etc. It's
>> not a proxy for "being piped" - it's that when your output isn't going
>> to a terminal, asking "what is my terminal size" isn't particularly
>> productive.
>
> Then explain why os.get_terminal_size() returns the correct answer.
>
> The output might not be going to a terminal (not directly at least) but the
> question isn't "what's the size of the terminal that output is going to".
> The question is "what's the size of the terminal that this process is
> running in", and that has an answer regardless of where output is piped.

Processes aren't always running "in" terminals, though. That's my
point. A terminal is not a fundamental feature of a process.

>> Would you expect a cronjob to use the terminal size when you
>> most recently edited crontab? No.
>
> Of course not -- the terminal where you edited crontab is not where the
> process is running. Why would it be the least bit relevant?

So where *is* that process running? What terminal is it in? Don't you
see how similar this is to the pipe situation - sure, there might be a
terminal that the program was invoked from, but it's utterly
irrelevant to how the program actually runs.

>> You might well be a completely background process.
>
> And if that background process is running in a terminal? What's your point?

Background processes don't have terminal access. Whether it's a daemon
or something started as "commandname >/dev/null 2>/dev/null </dev/null
&" from bash, it doesn't have access to a terminal.

Please don't assume that every program has a controlling UI. I get
enough of that mentality from the people I support on Windows, where
the fundamental assumption of people seems to be that there's a GUI
for everything. There isn't. And there isn't always a terminal either.
Processes in the middle of pipelines *do not have* terminals.

ChrisA


From marko at pacujo.net  Sat Jan 28 14:30:42 2017
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sat, 28 Jan 2017 21:30:42 +0200
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqR5G2jUA09RGEFQG-yOhiBikkAFH+MnaZ7UbioB5XYDA@mail.gmail.com>
 <mailman.115.1485592048.2473.python-list@python.org>
 <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmrQ6jNht0-V1KAL+Bumbqqm0n_3r8_MySO=p2DJQz5-0A@mail.gmail.com>
 <mailman.117.1485604215.2473.python-list@python.org>
 <588cc39f$0$1609$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmq6JgDcHQ+3YgWizeUa292+vOzRs6TB=n-chD8Q7f2STA@mail.gmail.com>
 <mailman.127.1485626324.2473.python-list@python.org>
Message-ID: <87r33nnfrx.fsf@elektro.pacujo.net>

Chris Angelico <rosuav at gmail.com>:
> Background processes don't have terminal access. Whether it's a daemon
> or something started as "commandname >/dev/null 2>/dev/null </dev/null
> &" from bash, it doesn't have access to a terminal.

A nitpick: a process running in the background or a process with no open
terminal file descriptor still does have a controlling terminal under
Unix/Linux.

<URL: http://man7.org/linux/man-pages/man4/tty.4.html>
<URL: https://docs.python.org/3/library/fcntl.html#fcntl.ioctl>
<URL: https://linux.die.net/man/2/setsid>
<URL: https://docs.python.org/3/library/os.html#os.setsid>


Marko


From grant.b.edwards at gmail.com  Sat Jan 28 15:02:48 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Sat, 28 Jan 2017 20:02:48 +0000 (UTC)
Subject: Is Python SSL API thread-safe?
References: <o63439$r2a$1@blaine.gmane.org>
 <4f923fe7-fa75-698e-37b9-3e4423c7e59b@python.org>
Message-ID: <o6itd8$kdi$1@blaine.gmane.org>

On 2017-01-22, Christian Heimes <christian at python.org> wrote:

> OpenSSL and Python's ssl module are thread-safe. However IO is not
> safe concerning reentrancy. You cannot safely share a SSLSocket
> between threads without a mutex. Certain aspects of the TLS protocol
> can cause interesting side effects. A recv() call can send data
> across a wire and a send() call can receive data from the wire,
> e.g. during re-keying.

And it looks to me like the Python SSL module does all of that.  It
provides mutexes and thread ID and locking callbacks as described in
the page below:

  https://www.openssl.org/docs/man1.0.2/crypto/threads.html

According to that page above it's safe to share the socket between
threads:

   OpenSSL can safely be used in multi-threaded applications provided
   that at least two callback functions are set, locking_function and
   threadid_func.

They python ssl module code does that, so python ssl sockets should be
thread safe.

Can you explain why you disagree?

Can you provide example code that demonstrates a failure?

> In order to archive reentrancy, you have to do all IO yourself by
> operating the SSL connection in non-blocking mode or with a
> Memorio-BIO https://docs.python.org/3/library/ssl.html#ssl-nonblocking

That section is about how to work with non-blocking sockets.  I'm not
using non-blocking sockets.

-- 
Grant Edwards               grant.b.edwards        Yow! Now I'm concentrating
                                  at               on a specific tank battle
                              gmail.com            toward the end of World
                                                   War II!



From eryksun at gmail.com  Sat Jan 28 15:04:45 2017
From: eryksun at gmail.com (eryk sun)
Date: Sat, 28 Jan 2017 20:04:45 +0000
Subject: Is shutil.get_terminal_size useless?
In-Reply-To: <CAPTjJmq6JgDcHQ+3YgWizeUa292+vOzRs6TB=n-chD8Q7f2STA@mail.gmail.com>
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqR5G2jUA09RGEFQG-yOhiBikkAFH+MnaZ7UbioB5XYDA@mail.gmail.com>
 <mailman.115.1485592048.2473.python-list@python.org>
 <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmrQ6jNht0-V1KAL+Bumbqqm0n_3r8_MySO=p2DJQz5-0A@mail.gmail.com>
 <mailman.117.1485604215.2473.python-list@python.org>
 <588cc39f$0$1609$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmq6JgDcHQ+3YgWizeUa292+vOzRs6TB=n-chD8Q7f2STA@mail.gmail.com>
Message-ID: <CACL+1asmnuhBqH10yeR761inr9nvw8F4xqD5TwXTWcN8jW6SuA@mail.gmail.com>

On Sat, Jan 28, 2017 at 5:58 PM, Chris Angelico <rosuav at gmail.com> wrote:
> Processes in the middle of pipelines *do not have* terminals.

No, in the following case stderr is a terminal:

    $ echo spam |
    > python3 -c 'import os
    > print(os.get_terminal_size(2))' |
    > cat
    os.terminal_size(columns=132, lines=43)

Let's also redirect stderr to the pipe:

    $ echo spam |
    > 2>&1 python3 -c 'import os
    > print(os.get_terminal_size(2))' |
    > cat

    Traceback (most recent call last):
      File "<string>", line 2, in <module>
    OSError: [Errno 25] Inappropriate ioctl for device

Now let's open and use the controlling terminal instead:

    $ echo spam |
    > 2>&1 python3 -c 'import os
    > fd = os.open("/dev/tty", os.O_RDONLY)
    > print(os.get_terminal_size(fd))' |
    > cat
    os.terminal_size(columns=132, lines=43)

Now let's get rid of the terminal via setsid:

   $ echo spam |
    > 2>&1 setsid python3 -c 'import os
    > fd = os.open("/dev/tty", os.O_RDONLY)
    > print(os.get_terminal_size(fd))' |
    > cat
    Traceback (most recent call last):
      File "<string>", line 2, in <module>
    OSError: [Errno 6] No such device or address: '/dev/tty'


From rosuav at gmail.com  Sat Jan 28 15:36:25 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 29 Jan 2017 07:36:25 +1100
Subject: Is shutil.get_terminal_size useless?
In-Reply-To: <CACL+1asmnuhBqH10yeR761inr9nvw8F4xqD5TwXTWcN8jW6SuA@mail.gmail.com>
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqR5G2jUA09RGEFQG-yOhiBikkAFH+MnaZ7UbioB5XYDA@mail.gmail.com>
 <mailman.115.1485592048.2473.python-list@python.org>
 <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmrQ6jNht0-V1KAL+Bumbqqm0n_3r8_MySO=p2DJQz5-0A@mail.gmail.com>
 <mailman.117.1485604215.2473.python-list@python.org>
 <588cc39f$0$1609$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmq6JgDcHQ+3YgWizeUa292+vOzRs6TB=n-chD8Q7f2STA@mail.gmail.com>
 <CACL+1asmnuhBqH10yeR761inr9nvw8F4xqD5TwXTWcN8jW6SuA@mail.gmail.com>
Message-ID: <CAPTjJmqCpbzT9rRXORaEW+tOLMpawqSCyk0FRU+QHpWixPNK9w@mail.gmail.com>

On Sun, Jan 29, 2017 at 7:04 AM, eryk sun <eryksun at gmail.com> wrote:
> Now let's get rid of the terminal via setsid:
>
>    $ echo spam |
>     > 2>&1 setsid python3 -c 'import os
>     > fd = os.open("/dev/tty", os.O_RDONLY)
>     > print(os.get_terminal_size(fd))' |
>     > cat
>     Traceback (most recent call last):
>       File "<string>", line 2, in <module>
>     OSError: [Errno 6] No such device or address: '/dev/tty'

And you could have achieved the same result in any number of other
ways, too, like setting yourself up with the local boot system (true
of systemd, upstart, sysvinit, and probably of all others too), or
cron, or inetd, etc, etc, etc. You can definitely lose access to your
"controlling terminal".

ChrisA


From marko at pacujo.net  Sat Jan 28 16:26:33 2017
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sat, 28 Jan 2017 23:26:33 +0200
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqR5G2jUA09RGEFQG-yOhiBikkAFH+MnaZ7UbioB5XYDA@mail.gmail.com>
 <mailman.115.1485592048.2473.python-list@python.org>
 <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmrQ6jNht0-V1KAL+Bumbqqm0n_3r8_MySO=p2DJQz5-0A@mail.gmail.com>
 <mailman.117.1485604215.2473.python-list@python.org>
 <588cc39f$0$1609$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmq6JgDcHQ+3YgWizeUa292+vOzRs6TB=n-chD8Q7f2STA@mail.gmail.com>
 <CACL+1asmnuhBqH10yeR761inr9nvw8F4xqD5TwXTWcN8jW6SuA@mail.gmail.com>
 <CAPTjJmqCpbzT9rRXORaEW+tOLMpawqSCyk0FRU+QHpWixPNK9w@mail.gmail.com>
 <mailman.130.1485635793.2473.python-list@python.org>
Message-ID: <87mveaooza.fsf@elektro.pacujo.net>

Chris Angelico <rosuav at gmail.com>:

> On Sun, Jan 29, 2017 at 7:04 AM, eryk sun <eryksun at gmail.com> wrote:
>> Now let's get rid of the terminal via setsid:
>>
>>    $ echo spam |
>>     > 2>&1 setsid python3 -c 'import os
>>     > fd = os.open("/dev/tty", os.O_RDONLY)
>>     > print(os.get_terminal_size(fd))' |
>>     > cat
>>     Traceback (most recent call last):
>>       File "<string>", line 2, in <module>
>>     OSError: [Errno 6] No such device or address: '/dev/tty'
>
> And you could have achieved the same result in any number of other
> ways, too, like setting yourself up with the local boot system (true
> of systemd, upstart, sysvinit, and probably of all others too), or
> cron, or inetd, etc, etc, etc. You can definitely lose access to your
> "controlling terminal".

Eryk has a real, deeper point worth getting acquainted with.

(Although if I were to design an operating system, I don't know if I
would bother with controlling terminals, job control or chirping
modems.)


Marko


From pavlovevidence at gmail.com  Sat Jan 28 20:35:17 2017
From: pavlovevidence at gmail.com (pavlovevidence at gmail.com)
Date: Sat, 28 Jan 2017 17:35:17 -0800 (PST)
Subject: How coding in Python is bad for you
In-Reply-To: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
Message-ID: <87ab542f-0473-40c1-8a56-b41b397fb8b2@googlegroups.com>

On Monday, January 23, 2017 at 9:24:56 AM UTC-8, bream... at gmail.com wrote:
> The article is here http://lenkaspace.net/index.php/blog/show/111
> 
> Kindest regards.
> 
> Mark Lawrence.

I remember the old days of Python when it was just Perl's little brother.  Sometimes I feel moments of amazement whenever someone makes this much of an effort to badmouth it (and this blog is definitely badmouthing it, very little of criticism is reasonable).

Carl Banks


From grant.b.edwards at gmail.com  Sat Jan 28 21:53:03 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Sun, 29 Jan 2017 02:53:03 +0000 (UTC)
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqR5G2jUA09RGEFQG-yOhiBikkAFH+MnaZ7UbioB5XYDA@mail.gmail.com>
 <mailman.115.1485592048.2473.python-list@python.org>
 <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmrQ6jNht0-V1KAL+Bumbqqm0n_3r8_MySO=p2DJQz5-0A@mail.gmail.com>
 <mailman.117.1485604215.2473.python-list@python.org>
 <588cc39f$0$1609$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmq6JgDcHQ+3YgWizeUa292+vOzRs6TB=n-chD8Q7f2STA@mail.gmail.com>
 <CACL+1asmnuhBqH10yeR761inr9nvw8F4xqD5TwXTWcN8jW6SuA@mail.gmail.com>
 <CAPTjJmqCpbzT9rRXORaEW+tOLMpawqSCyk0FRU+QHpWixPNK9w@mail.gmail.com>
 <mailman.130.1485635793.2473.python-list@python.org>
 <87mveaooza.fsf@elektro.pacujo.net>
Message-ID: <o6jlef$5i4$1@blaine.gmane.org>

On 2017-01-28, Marko Rauhamaa <marko at pacujo.net> wrote:

> (Although if I were to design an operating system, I don't know if I
> would bother with controlling terminals, job control or chirping
> modems.)

I've been using serial ports on Unix for 35 years, and maintaining
serial drivers for Linux for almost 20. Many days, it seems like the
tty/serial API in Unix is the rug under which all the ugly dirt got
swept...

Then I think about X.

and I guess the networking stuff gets ugly pretty fast when you look
under the hood.

It's really pretty impressive how orthogonal they did manage to make
things.

-- 
Grant




From juan0christian at gmail.com  Sat Jan 28 22:06:31 2017
From: juan0christian at gmail.com (Juan C.)
Date: Sun, 29 Jan 2017 01:06:31 -0200
Subject: What are your opinions on .NET Core vs Python?
Message-ID: <CAAp0bGup1DOJBU0+52eqsb-XqOi6Pv1zGJ2bWvgUMtPuZ1v3YA@mail.gmail.com>

As you guys might know, .NET Core is up and running, promising a
"cross-platform, unified, fast, lightweight, modern and open source
experience" (source: .NET Core official site). What do you guys think about
it? Do you think it will be able to compete with and overcome Python in the
opensource medium?


From python at deborahswanson.net  Sun Jan 29 04:11:28 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sun, 29 Jan 2017 01:11:28 -0800
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <CAAp0bGup1DOJBU0+52eqsb-XqOi6Pv1zGJ2bWvgUMtPuZ1v3YA@mail.gmail.com>
Message-ID: <007801d27a0f$ad381e80$27b23dae@sambora>

Juan C. wrote, on Saturday, January 28, 2017 7:07 PM
> 
> As you guys might know, .NET Core is up and running, 
> promising a "cross-platform, unified, fast, lightweight, 
> modern and open source experience" (source: .NET Core 
> official site). What do you guys think about it? Do you think 
> it will be able to compete with and overcome Python in the 
> opensource medium?

I don't really know what .NET does these days, but looking at the list
of languages it supports:
https://en.wikipedia.org/wiki/List_of_CLI_languages#Current_Languages
I don't see any I'd likely want to use instead of Python, with the
possible exception of IronPython. A few people on this list have
mentioned it, but I don't really see any good reason to paste any
version of Python onto some other kind of system. Unless maybe you're
required to use that system for some other reason.

Most of the languages on this "List_of_CLI_languages" supported by .NET
have already been shown to my satisfaction to have been overtaken and
subsumed by Python. It's a good thing that .NET's framework has shed
some baggage, which was sorely needed, but what really matters is what
you can do with it. And given the choices of languages available in
.NET, in most cases I think you'd be better off working in straight
Python. You can't put lipstick on a pig. It will still be a pig, even if
you give it flashy sunglasses and put it on jetskis.



From marko at pacujo.net  Sun Jan 29 04:23:49 2017
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sun, 29 Jan 2017 11:23:49 +0200
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqR5G2jUA09RGEFQG-yOhiBikkAFH+MnaZ7UbioB5XYDA@mail.gmail.com>
 <mailman.115.1485592048.2473.python-list@python.org>
 <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmrQ6jNht0-V1KAL+Bumbqqm0n_3r8_MySO=p2DJQz5-0A@mail.gmail.com>
 <mailman.117.1485604215.2473.python-list@python.org>
 <588cc39f$0$1609$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmq6JgDcHQ+3YgWizeUa292+vOzRs6TB=n-chD8Q7f2STA@mail.gmail.com>
 <CACL+1asmnuhBqH10yeR761inr9nvw8F4xqD5TwXTWcN8jW6SuA@mail.gmail.com>
 <CAPTjJmqCpbzT9rRXORaEW+tOLMpawqSCyk0FRU+QHpWixPNK9w@mail.gmail.com>
 <mailman.130.1485635793.2473.python-list@python.org>
 <87mveaooza.fsf@elektro.pacujo.net> <o6jlef$5i4$1@blaine.gmane.org>
 <mailman.131.1485658400.2473.python-list@python.org>
Message-ID: <87fuk2dxsq.fsf@elektro.pacujo.net>

Grant Edwards <grant.b.edwards at gmail.com>:

> On 2017-01-28, Marko Rauhamaa <marko at pacujo.net> wrote:
>
>> (Although if I were to design an operating system, I don't know if I
>> would bother with controlling terminals, job control or chirping
>> modems.)
>
> I've been using serial ports on Unix for 35 years, and maintaining
> serial drivers for Linux for almost 20. Many days, it seems like the
> tty/serial API in Unix is the rug under which all the ugly dirt got
> swept...
>
> [...]
>
> It's really pretty impressive how orthogonal they did manage to make
> things.

I *have* been longing for a serial console in linux distros. That would
make it possible to set up virtual machines from ISO images
automatically as virtualization environments can emulate a serial
interface with an SSH connection. As it stands, such automation requires
ugly, brittle VNC tricks.


Marko


From gerald.britton at gmail.com  Sun Jan 29 07:51:48 2017
From: gerald.britton at gmail.com (Gerald Britton)
Date: Sun, 29 Jan 2017 07:51:48 -0500
Subject: Fwd: What are your opinions on .NET Core vs Python?
In-Reply-To: <CAPxRSnZQP7RqYr9ijuhVWf6QdUWjqS29Rg6OuM5C-vFwZemLWA@mail.gmail.com>
References: <CAPxRSnZQP7RqYr9ijuhVWf6QdUWjqS29Rg6OuM5C-vFwZemLWA@mail.gmail.com>
Message-ID: <CAPxRSnYh0E_K-FGVpdhDK2gxCgzEd5b8_-tysQDGY75VSFC+6Q@mail.gmail.com>

>
> As you guys might know, .NET Core is up and running, promising a
> "cross-platform, unified, fast, lightweight, modern and open source
> experience" (source: .NET Core official site). What do you guys think about
> it? Do you think it will be able to compete with and overcome Python in the
> opensource medium?


It's an apples/oranges comparison.

.NET is a library that can be used from many languages, including Python.
 (Not just IronPython, but also Python for .NET (pythonnet.sourceforge*.*net
*))*

Python is a language that can use many libraries, including .NET

The set of libraries that can be used from all the languages that can also
use .NET (out of the box, that is) is smaller.


From bc at freeuk.com  Sun Jan 29 08:05:48 2017
From: bc at freeuk.com (BartC)
Date: Sun, 29 Jan 2017 13:05:48 +0000
Subject: How coding in Python is bad for you
In-Reply-To: <87ab542f-0473-40c1-8a56-b41b397fb8b2@googlegroups.com>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <87ab542f-0473-40c1-8a56-b41b397fb8b2@googlegroups.com>
Message-ID: <o6kp86$chs$1@dont-email.me>

On 29/01/2017 01:35, pavlovevidence at gmail.com wrote:
> On Monday, January 23, 2017 at 9:24:56 AM UTC-8, bream... at gmail.com wrote:
>> The article is here http://lenkaspace.net/index.php/blog/show/111
>>
>> Kindest regards.
>>
>> Mark Lawrence.
>
> I remember the old days of Python when it was just Perl's little brother.  Sometimes I feel moments of amazement whenever someone makes this much of an effort to badmouth it (and this blog is definitely badmouthing it, very little of criticism is reasonable).

I think it's completely reasonable for anyone to criticise Python if 
they want (or any other computer language for that matter).

(And it didn't cover that much; I could do a far more in-depth critique 
if I wanted.)

What might be unreasonable is to criticise it in a /Python/ group full 
of language aficionados who are going to view every feature and quirk of 
the language in a good light; nothing is ever a problem!

But the author of piece didn't post it here.

-- 
bartc


From rosuav at gmail.com  Sun Jan 29 08:17:43 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 30 Jan 2017 00:17:43 +1100
Subject: How coding in Python is bad for you
In-Reply-To: <o6kp86$chs$1@dont-email.me>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <87ab542f-0473-40c1-8a56-b41b397fb8b2@googlegroups.com>
 <o6kp86$chs$1@dont-email.me>
Message-ID: <CAPTjJmr3hixvGMKvDokPKvZUhJ7OAuM6VDf5io=tWBgb1t6q=A@mail.gmail.com>

On Mon, Jan 30, 2017 at 12:05 AM, BartC <bc at freeuk.com> wrote:
> On 29/01/2017 01:35, pavlovevidence at gmail.com wrote:
>>
>> On Monday, January 23, 2017 at 9:24:56 AM UTC-8, bream... at gmail.com wrote:
>>>
>>> The article is here http://lenkaspace.net/index.php/blog/show/111
>>>
>>> Kindest regards.
>>>
>>> Mark Lawrence.
>>
>>
>> I remember the old days of Python when it was just Perl's little brother.
>> Sometimes I feel moments of amazement whenever someone makes this much of an
>> effort to badmouth it (and this blog is definitely badmouthing it, very
>> little of criticism is reasonable).
>
>
> I think it's completely reasonable for anyone to criticise Python if they
> want (or any other computer language for that matter).
>
> (And it didn't cover that much; I could do a far more in-depth critique if I
> wanted.)
>
> What might be unreasonable is to criticise it in a /Python/ group full of
> language aficionados who are going to view every feature and quirk of the
> language in a good light; nothing is ever a problem!
>
> But the author of piece didn't post it here.

It's completely reasonable for someone to critique Python. It's not
reasonable to post a bunch of baseless FUD, regardless of your forum.

There's plenty in Python that you can legitimately criticise.
Sometimes you'll get a response of "actually this is good, because X,
Y, Z"; sometimes you get "well, what you suggest is marginally better,
but not enough to justify breaking backward compatibility"; and
sometimes you get "good point, maybe we can change that in the next
version - want to write a patch?". But when all your criticisms are
either (a) true of virtually every programming language, yet you claim
they're Python's faults; or (b) actually false, you just make yourself
look like a troll.

ChrisA


From steve+python at pearwood.info  Sun Jan 29 09:42:15 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Mon, 30 Jan 2017 01:42:15 +1100
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <87ab542f-0473-40c1-8a56-b41b397fb8b2@googlegroups.com>
 <o6kp86$chs$1@dont-email.me>
Message-ID: <588dff48$0$22142$c3e8da3$5496439d@news.astraweb.com>

On Mon, 30 Jan 2017 12:05 am, BartC wrote:

> What might be unreasonable is to criticise it in a Python group full
> of language aficionados who are going to view every feature and quirk of
> the language in a good light; 

It's all about the trade-offs we choose to make. Its not that we don't
understand that feature X has a downside; its that we value that feature
enough to make up for it.


> nothing is ever a problem! 

1. for...else is misspelled, and should be for...then;

2. Same for while...else;

3. shutil.get_terminal_size() is broken by design;

4. Decimal is not integrated with the numeric tower;

5. The statistics module is too slow (and if I ever meet the author, I'll
give him a kick in the head);

6. duck-typing with numbers often fails, requiring you to resort to
polymorphic code with type checking;

7. which is too slow;

8. fractions could easily support infinities (?1/0) and NAN (0/0) but don't;

9. the state of GUI toolkits in 2017 is nowhere near as easy to use as
Hypercard in 1986 (although that doesn't apply just to Python);

10. packaging is still too complex and hard to get right;

11. the last couple of years has seen an emphasis on asynchronous
programming that I don't understand and scares me;

12. there's no try...except expression;

13. or constants;

14. writing bullet-proof file handling code (e.g. atomic file save that
either is guaranteed to write to the disk or guaranteed to leave the
previous file contents in place) is too hard;

15. str.centre() is misspelled;

16. despite what the Zen says, there aren't enough namespaces;

17. unicodedata is missing a lot of functionality;

18. CPython makes object IDs look like memory addresses;

19. there's no way to tell the compiler to do certain calculations at
compile-time, instead of run-time;

20. the utf-8 encoder is strict, but the utf-16 and utf-32 encoders are not,
which makes them technically non-compliant;

21. the CPython compiler isn't smart enough, and so has to forgo the
opportunity for optimizations which apply 99.9% of the time, because of the
0.1% of the time that they don't apply (e.g. in-lining functions);

22. there's no syntax for Design By Contract;

23. no support for Snobol/Icon like string patterns (BNF context-free
grammars, more powerful than regular expressions);

24. lack of support for Prolog-like logic programming paradigm;

25. no way to bail out of generator expressions early, e.g. (expr for x in
seq while condition);

26. the glob module doesn't support escaping, or {a,b,c} alternatives;

27. in hindsight, all() and any() shouldn't coerce their result to True or
False, but return a truthy or falsey value from their inputs.


That's just off the top of my head. Is that enough for you?




-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From grant.b.edwards at gmail.com  Sun Jan 29 11:07:26 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Sun, 29 Jan 2017 16:07:26 +0000 (UTC)
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqR5G2jUA09RGEFQG-yOhiBikkAFH+MnaZ7UbioB5XYDA@mail.gmail.com>
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 <588cc39f$0$1609$c3e8da3$5496439d@news.astraweb.com>
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 <CACL+1asmnuhBqH10yeR761inr9nvw8F4xqD5TwXTWcN8jW6SuA@mail.gmail.com>
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 <mailman.130.1485635793.2473.python-list@python.org>
 <87mveaooza.fsf@elektro.pacujo.net> <o6jlef$5i4$1@blaine.gmane.org>
 <mailman.131.1485658400.2473.python-list@python.org>
 <87fuk2dxsq.fsf@elektro.pacujo.net>
Message-ID: <o6l3vu$4jf$1@blaine.gmane.org>

On 2017-01-29, Marko Rauhamaa <marko at pacujo.net> wrote:
> Grant Edwards <grant.b.edwards at gmail.com>:
>
>> On 2017-01-28, Marko Rauhamaa <marko at pacujo.net> wrote:
>>
>>> (Although if I were to design an operating system, I don't know if I
>>> would bother with controlling terminals, job control or chirping
>>> modems.)
>>
>> I've been using serial ports on Unix for 35 years, and maintaining
>> serial drivers for Linux for almost 20. Many days, it seems like the
>> tty/serial API in Unix is the rug under which all the ugly dirt got
>> swept...
>>
>> [...]
>>
>> It's really pretty impressive how orthogonal they did manage to make
>> things.
>
> I *have* been longing for a serial console in linux distros.

Well, all it takes is a tweak to the bootloader to add a kernel
"command-line" parameter...

> That would make it possible to set up virtual machines from ISO
> images automatically as virtualization environments can emulate a
> serial interface with an SSH connection. As it stands, such
> automation requires ugly, brittle VNC tricks.

-- 
Grant




From marko at pacujo.net  Sun Jan 29 11:28:08 2017
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sun, 29 Jan 2017 18:28:08 +0200
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqR5G2jUA09RGEFQG-yOhiBikkAFH+MnaZ7UbioB5XYDA@mail.gmail.com>
 <mailman.115.1485592048.2473.python-list@python.org>
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 <mailman.130.1485635793.2473.python-list@python.org>
 <87mveaooza.fsf@elektro.pacujo.net> <o6jlef$5i4$1@blaine.gmane.org>
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 <87fuk2dxsq.fsf@elektro.pacujo.net> <o6l3vu$4jf$1@blaine.gmane.org>
 <mailman.136.1485706995.2473.python-list@python.org>
Message-ID: <87bmupespz.fsf@elektro.pacujo.net>

Grant Edwards <grant.b.edwards at gmail.com>:

> On 2017-01-29, Marko Rauhamaa <marko at pacujo.net> wrote:
>> I *have* been longing for a serial console in linux distros.
>
> Well, all it takes is a tweak to the bootloader to add a kernel
> "command-line" parameter...

Can you give me a short Python script that effects the tweak to an ISO
image? I need to run the script as a regular user.


Marko


From rosuav at gmail.com  Sun Jan 29 11:32:41 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 30 Jan 2017 03:32:41 +1100
Subject: Is shutil.get_terminal_size useless?
In-Reply-To: <87bmupespz.fsf@elektro.pacujo.net>
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmqR5G2jUA09RGEFQG-yOhiBikkAFH+MnaZ7UbioB5XYDA@mail.gmail.com>
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 <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>
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 <mailman.136.1485706995.2473.python-list@python.org>
 <87bmupespz.fsf@elektro.pacujo.net>
Message-ID: <CAPTjJmrJ_j+UoZOh8hPkxwyv1CtazVSZOn8jsZykXjrBLEZg2A@mail.gmail.com>

On Mon, Jan 30, 2017 at 3:28 AM, Marko Rauhamaa <marko at pacujo.net> wrote:
> Grant Edwards <grant.b.edwards at gmail.com>:
>
>> On 2017-01-29, Marko Rauhamaa <marko at pacujo.net> wrote:
>>> I *have* been longing for a serial console in linux distros.
>>
>> Well, all it takes is a tweak to the bootloader to add a kernel
>> "command-line" parameter...
>
> Can you give me a short Python script that effects the tweak to an ISO
> image? I need to run the script as a regular user.

It'd start by mounting it somewhere, and finish by building a new ISO
with mkisofs, so a shell script would be more appropriate :)

ChrisA


From marko at pacujo.net  Sun Jan 29 11:44:55 2017
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sun, 29 Jan 2017 18:44:55 +0200
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>
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 <mailman.117.1485604215.2473.python-list@python.org>
 <588cc39f$0$1609$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmq6JgDcHQ+3YgWizeUa292+vOzRs6TB=n-chD8Q7f2STA@mail.gmail.com>
 <CACL+1asmnuhBqH10yeR761inr9nvw8F4xqD5TwXTWcN8jW6SuA@mail.gmail.com>
 <CAPTjJmqCpbzT9rRXORaEW+tOLMpawqSCyk0FRU+QHpWixPNK9w@mail.gmail.com>
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 <87mveaooza.fsf@elektro.pacujo.net> <o6jlef$5i4$1@blaine.gmane.org>
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 <87fuk2dxsq.fsf@elektro.pacujo.net> <o6l3vu$4jf$1@blaine.gmane.org>
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 <mailman.137.1485707569.2473.python-list@python.org>
Message-ID: <877f5dery0.fsf@elektro.pacujo.net>

Chris Angelico <rosuav at gmail.com>:

> On Mon, Jan 30, 2017 at 3:28 AM, Marko Rauhamaa <marko at pacujo.net> wrote:
>> Grant Edwards <grant.b.edwards at gmail.com>:
>>
>>> On 2017-01-29, Marko Rauhamaa <marko at pacujo.net> wrote:
>>>> I *have* been longing for a serial console in linux distros.
>>>
>>> Well, all it takes is a tweak to the bootloader to add a kernel
>>> "command-line" parameter...
>>
>> Can you give me a short Python script that effects the tweak to an ISO
>> image? I need to run the script as a regular user.
>
> It'd start by mounting it somewhere, and finish by building a new ISO
> with mkisofs, so a shell script would be more appropriate :)

Mount? As a regular user?


Marko


From rosuav at gmail.com  Sun Jan 29 11:53:43 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 30 Jan 2017 03:53:43 +1100
Subject: Is shutil.get_terminal_size useless?
In-Reply-To: <877f5dery0.fsf@elektro.pacujo.net>
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>
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Message-ID: <CAPTjJmpada8a2fjPUuXQR08WJCLtQNuaM7MTRpB1i-=O_J0pMQ@mail.gmail.com>

On Mon, Jan 30, 2017 at 3:44 AM, Marko Rauhamaa <marko at pacujo.net> wrote:
> Chris Angelico <rosuav at gmail.com>:
>
>> On Mon, Jan 30, 2017 at 3:28 AM, Marko Rauhamaa <marko at pacujo.net> wrote:
>>> Grant Edwards <grant.b.edwards at gmail.com>:
>>>
>>>> On 2017-01-29, Marko Rauhamaa <marko at pacujo.net> wrote:
>>>>> I *have* been longing for a serial console in linux distros.
>>>>
>>>> Well, all it takes is a tweak to the bootloader to add a kernel
>>>> "command-line" parameter...
>>>
>>> Can you give me a short Python script that effects the tweak to an ISO
>>> image? I need to run the script as a regular user.
>>
>> It'd start by mounting it somewhere, and finish by building a new ISO
>> with mkisofs, so a shell script would be more appropriate :)
>
> Mount? As a regular user?

Let me see, how much effort are you prepared to go to in order to do
this as a "regular user"... because at some point, "sudo" becomes only
one of many options, including "install another Unix system somewhere
that you are root of". But if you genuinely have to mount as a
non-root user, there's fusermount, which is often capable of loading
up an ISO.

But honestly, "ssh you at somebox" can be run by anyone, so there's
always a way around the whole not-having-root thing.

ChrisA


From grant.b.edwards at gmail.com  Sun Jan 29 11:56:28 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Sun, 29 Jan 2017 16:56:28 +0000 (UTC)
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>
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 <CAPTjJmrJ_j+UoZOh8hPkxwyv1CtazVSZOn8jsZykXjrBLEZg2A@mail.gmail.com>
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 <877f5dery0.fsf@elektro.pacujo.net>
Message-ID: <o6l6rs$cfu$1@blaine.gmane.org>

On 2017-01-29, Marko Rauhamaa <marko at pacujo.net> wrote:
> Chris Angelico <rosuav at gmail.com>:
>
>> On Mon, Jan 30, 2017 at 3:28 AM, Marko Rauhamaa <marko at pacujo.net> wrote:
>>> Grant Edwards <grant.b.edwards at gmail.com>:
>>>
>>>> On 2017-01-29, Marko Rauhamaa <marko at pacujo.net> wrote:
>>>>> I *have* been longing for a serial console in linux distros.
>>>>
>>>> Well, all it takes is a tweak to the bootloader to add a kernel
>>>> "command-line" parameter...
>>>
>>> Can you give me a short Python script that effects the tweak to an ISO
>>> image? I need to run the script as a regular user.
>>
>> It'd start by mounting it somewhere, and finish by building a new ISO
>> with mkisofs, so a shell script would be more appropriate :)
>
> Mount? As a regular user?

https://linux.die.net/man/8/isoinfo

-- 
Grant





From grant.b.edwards at gmail.com  Sun Jan 29 12:08:23 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Sun, 29 Jan 2017 17:08:23 +0000 (UTC)
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <588c7728$0$1602$c3e8da3$5496439d@news.astraweb.com>
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 <877f5dery0.fsf@elektro.pacujo.net>
Message-ID: <o6l7i7$lhp$1@blaine.gmane.org>

On 2017-01-29, Marko Rauhamaa <marko at pacujo.net> wrote:

> Mount? As a regular user?

Yes, using a "fuse" use-space filesystem, you can mount things as a
normal user. There are a couple ISO9660 fuse implemenations.  But, you
can't modify a mounted ISO9660 filesystem.  I have read about how to
use a union mount to simulate a writable ISO9660 filesystem, but
that's going to require root (I've never tried it).

As long as you've got the disk space available, the simplest option is
to unpack the .iso into a directory, modify the files, and then use
mkisofs to create the new .iso image.

I've written scripts like that to build cusotmized bootable ISO images
(usually using systemrescuecd as the starting point).  It's not
particulary difficult, but it does burn up a lot of disk space.  It's
also rather slow, so when you get into the tweak-build-burn-test cycle
you don't get in a lot of guesses-per-hour.

-- 
Grant




From rosuav at gmail.com  Sun Jan 29 12:13:48 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 30 Jan 2017 04:13:48 +1100
Subject: Is shutil.get_terminal_size useless?
In-Reply-To: <o6l7i7$lhp$1@blaine.gmane.org>
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
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 <CAPTjJmqCpbzT9rRXORaEW+tOLMpawqSCyk0FRU+QHpWixPNK9w@mail.gmail.com>
 <mailman.130.1485635793.2473.python-list@python.org>
 <87mveaooza.fsf@elektro.pacujo.net> <o6jlef$5i4$1@blaine.gmane.org>
 <mailman.131.1485658400.2473.python-list@python.org>
 <87fuk2dxsq.fsf@elektro.pacujo.net> <o6l3vu$4jf$1@blaine.gmane.org>
 <mailman.136.1485706995.2473.python-list@python.org>
 <87bmupespz.fsf@elektro.pacujo.net>
 <CAPTjJmrJ_j+UoZOh8hPkxwyv1CtazVSZOn8jsZykXjrBLEZg2A@mail.gmail.com>
 <mailman.137.1485707569.2473.python-list@python.org>
 <877f5dery0.fsf@elektro.pacujo.net> <o6l7i7$lhp$1@blaine.gmane.org>
Message-ID: <CAPTjJmpH_oM4v21=cenPtNQbcQy_zJQ_fokoj8M-=LyAE_xcBA@mail.gmail.com>

On Mon, Jan 30, 2017 at 4:08 AM, Grant Edwards
<grant.b.edwards at gmail.com> wrote:
> As long as you've got the disk space available, the simplest option is
> to unpack the .iso into a directory, modify the files, and then use
> mkisofs to create the new .iso image.
>
> I've written scripts like that to build cusotmized bootable ISO images
> (usually using systemrescuecd as the starting point).  It's not
> particulary difficult, but it does burn up a lot of disk space.  It's
> also rather slow, so when you get into the tweak-build-burn-test cycle
> you don't get in a lot of guesses-per-hour.

These days, CD images are a tiny proportion of typical hard disk
capacities. Every terabyte of disk can hold over a thousand ISOs, and
that's assuming they're using the whole disc (~760MB). Several
thousand, if they're only part-full images.

But the time factor is considerable. Especially if you then have to
boot up a VM or something to test it.

ChrisA


From cl at isbd.net  Sun Jan 29 12:18:38 2017
From: cl at isbd.net (Chris Green)
Date: Sun, 29 Jan 2017 17:18:38 +0000
Subject: Looking for a basic address book/contacts program
Message-ID: <eok1md-ji9.ln1@esprimo.zbmc.eu>

I'm looking for a simple Address Book program written in Python, I've
looked at addressbook 1.0.1 from PyPi but it doesn't quite do what I
want.  I may have to start with this and modify it but maybe there's
something better out there.

In particular I want some sort of import/export ability and I'd really
like some more configurability.

Any ideas anyone?

-- 
Chris Green
?


From marko at pacujo.net  Sun Jan 29 12:22:49 2017
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sun, 29 Jan 2017 19:22:49 +0200
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <mailman.117.1485604215.2473.python-list@python.org>
 <588cc39f$0$1609$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmq6JgDcHQ+3YgWizeUa292+vOzRs6TB=n-chD8Q7f2STA@mail.gmail.com>
 <CACL+1asmnuhBqH10yeR761inr9nvw8F4xqD5TwXTWcN8jW6SuA@mail.gmail.com>
 <CAPTjJmqCpbzT9rRXORaEW+tOLMpawqSCyk0FRU+QHpWixPNK9w@mail.gmail.com>
 <mailman.130.1485635793.2473.python-list@python.org>
 <87mveaooza.fsf@elektro.pacujo.net> <o6jlef$5i4$1@blaine.gmane.org>
 <mailman.131.1485658400.2473.python-list@python.org>
 <87fuk2dxsq.fsf@elektro.pacujo.net> <o6l3vu$4jf$1@blaine.gmane.org>
 <mailman.136.1485706995.2473.python-list@python.org>
 <87bmupespz.fsf@elektro.pacujo.net>
 <CAPTjJmrJ_j+UoZOh8hPkxwyv1CtazVSZOn8jsZykXjrBLEZg2A@mail.gmail.com>
 <mailman.137.1485707569.2473.python-list@python.org>
 <877f5dery0.fsf@elektro.pacujo.net>
 <CAPTjJmpada8a2fjPUuXQR08WJCLtQNuaM7MTRpB1i-=O_J0pMQ@mail.gmail.com>
 <mailman.138.1485708831.2473.python-list@python.org>
Message-ID: <871svleq6u.fsf@elektro.pacujo.net>

Chris Angelico <rosuav at gmail.com>:

> On Mon, Jan 30, 2017 at 3:44 AM, Marko Rauhamaa <marko at pacujo.net> wrote:
>> Mount? As a regular user?
>
> Let me see, how much effort are you prepared to go to in order to do
> this as a "regular user"... because at some point, "sudo" becomes only
> one of many options, including "install another Unix system somewhere
> that you are root of". But if you genuinely have to mount as a
> non-root user, there's fusermount, which is often capable of loading
> up an ISO.
>
> But honestly, "ssh you at somebox" can be run by anyone, so there's
> always a way around the whole not-having-root thing.

At the moment, we have found it easiest to create our base OS snapshots
with some manual steps. Ideally, we could get rid of the manual steps
and just have a python script take the place of the human user. That
would be trivial if the distros continued the grand tradition of
offering serial consoles out of the box.

As it stands, all methods of working serial-interface support in the ISO
image would still be more trouble than the manual steps.

We also use "Packer" to build virtual machines automatically. That works
albeit in a somewhat kludgy manner. As far as I understand, Packer
delivers keystrokes to the boot command over VNC but can't interpret the
graphical responses but simply trusts that the commands do the right
thing with a proper timing.


Marko


From grant.b.edwards at gmail.com  Sun Jan 29 12:27:07 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Sun, 29 Jan 2017 17:27:07 +0000 (UTC)
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmrQ6jNht0-V1KAL+Bumbqqm0n_3r8_MySO=p2DJQz5-0A@mail.gmail.com>
 <mailman.117.1485604215.2473.python-list@python.org>
 <588cc39f$0$1609$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmq6JgDcHQ+3YgWizeUa292+vOzRs6TB=n-chD8Q7f2STA@mail.gmail.com>
 <CACL+1asmnuhBqH10yeR761inr9nvw8F4xqD5TwXTWcN8jW6SuA@mail.gmail.com>
 <CAPTjJmqCpbzT9rRXORaEW+tOLMpawqSCyk0FRU+QHpWixPNK9w@mail.gmail.com>
 <mailman.130.1485635793.2473.python-list@python.org>
 <87mveaooza.fsf@elektro.pacujo.net> <o6jlef$5i4$1@blaine.gmane.org>
 <mailman.131.1485658400.2473.python-list@python.org>
 <87fuk2dxsq.fsf@elektro.pacujo.net> <o6l3vu$4jf$1@blaine.gmane.org>
 <mailman.136.1485706995.2473.python-list@python.org>
 <87bmupespz.fsf@elektro.pacujo.net>
 <CAPTjJmrJ_j+UoZOh8hPkxwyv1CtazVSZOn8jsZykXjrBLEZg2A@mail.gmail.com>
 <mailman.137.1485707569.2473.python-list@python.org>
 <877f5dery0.fsf@elektro.pacujo.net> <o6l7i7$lhp$1@blaine.gmane.org>
Message-ID: <o6l8la$j04$1@blaine.gmane.org>

On 2017-01-29, Grant Edwards <grant.b.edwards at gmail.com> wrote:
> On 2017-01-29, Marko Rauhamaa <marko at pacujo.net> wrote:
>
>> Mount? As a regular user?
>
> Yes, using a "fuse" use-space filesystem, you can mount things as a
> normal user. There are a couple ISO9660 fuse implemenations.  But, you
> can't modify a mounted ISO9660 filesystem.  I have read about how to
> use a union mount to simulate a writable ISO9660 filesystem, but
> that's going to require root (I've never tried it).
>
> As long as you've got the disk space available, the simplest option is
> to unpack the .iso into a directory, modify the files, and then use
> mkisofs to create the new .iso image.

OK, just one more level of pointless digression...

_If_ your ISO image is using syslinux as the bootloader (it probably
isn't, it's almost certainly using isolinux -- usually in hybrid
mode), then the bootloader stuff is actually an image of a bootable
floppy disk. It is sort of "outside" the normal ISO9660 filesystem
with a fixed size in a "well known" location.  I'm pretty sure you
could extract that chunk from the ISO using dd, tweak it, and then put
it back into the ISO image without having to mount/extract everything
and then recreate a new ISO9660 image.

But, it's very probably using isolinux, so the bootloader
configuration stuff is actually inside the ISO9660 filesystem tree,
and you'll have to extract the whole tree, modify the files, and
create a new ISO9660 image.

-- 
Grant



From vinay_sajip at yahoo.co.uk  Sun Jan 29 13:53:44 2017
From: vinay_sajip at yahoo.co.uk (Vinay Sajip)
Date: Sun, 29 Jan 2017 18:53:44 +0000 (UTC)
Subject: ANN: A new version (0.4.0) of python-gnupg has been released.
References: <1452661764.26048248.1485716024551.ref@mail.yahoo.com>
Message-ID: <1452661764.26048248.1485716024551@mail.yahoo.com>

A new version of the Python module which wraps GnuPG has been released.

What Changed?
=============
This is an enhancement and bug-fix release, and all users are encouraged to upgrade.
See the project website [1] for more information.

Brief summary:


* Added support for ``KEY_CONSIDERED`` in more places - encryption /
  decryption, signing, key generation and key import.

* Partial fix for #32 (GPG 2.1 compatibility). Unfortunately, better
  support cannot be provided at this point, unless there are certain
  changes (relating to pinentry popups) in how GPG 2.1 works.

* Fixed #60: An IndexError was being thrown by ``scan_keys()``.

* Ensured that utf-8 encoding is used when the ``--with-column`` mode is
  used. Thanks to Yann Leboulanger for the patch.

* ``list_keys()`` now uses ``--fixed-list-mode``. Thanks to Werner Koch
  for the pointer.

This release [2] has been signed with my code signing key:

Vinay Sajip (CODE SIGNING KEY) <vina... at yahoo.co.uk>
Fingerprint: CA74 9061 914E AC13 8E66 EADB 9147 B477 339A 9B86

What Does It Do?
================
The gnupg module allows Python programs to make use of the
functionality provided by the Gnu Privacy Guard (abbreviated GPG or
GnuPG). Using this module, Python programs can encrypt and decrypt
data, digitally sign documents and verify digital signatures, manage
(generate, list and delete) encryption keys, using proven Public Key
Infrastructure (PKI) encryption technology based on OpenPGP.

This module is expected to be used with Python versions >= 2.4, as it
makes use of the subprocess module which appeared in that version of
Python. This module is a newer version derived from earlier work by
Andrew Kuchling, Richard Jones and Steve Traugott.

A test suite using unittest is included with the source distribution.

Simple usage:

>>> import gnupg
>>> gpg = gnupg.GPG(gnupghome='/path/to/keyring/directory')
>>> gpg.list_keys()

[{
...
'fingerprint': 'F819EE7705497D73E3CCEE65197D5DAC68F1AAB2',
'keyid': '197D5DAC68F1AAB2',
'length': '1024',
'type': 'pub',
'uids': ['', 'Gary Gross (A test user) <gary.gr... at gamma.com>']},
{
...
'fingerprint': '37F24DD4B918CC264D4F31D60C5FEFA7A921FC4A',
'keyid': '0C5FEFA7A921FC4A',
'length': '1024',
...
'uids': ['', 'Danny Davis (A test user) <danny.da... at delta.com>']}]
>>> encrypted = gpg.encrypt("Hello, world!", ['0C5FEFA7A921FC4A'])
>>> str(encrypted)

'-----BEGIN PGP MESSAGE-----\nVersion: GnuPG v1.4.9 (GNU/Linux)\n
\nhQIOA/6NHMDTXUwcEAf
.
-----END PGP MESSAGE-----\n'
>>> decrypted = gpg.decrypt(str(encrypted), passphrase='secret')
>>> str(decrypted)

'Hello, world!'
>>> signed = gpg.sign("Goodbye, world!", passphrase='secret')
>>> verified = gpg.verify(str(signed))
>>> print "Verified" if verified else "Not verified"

'Verified'

As always, your feedback is most welcome (especially bug reports [3],
patches and suggestions for improvement, or any other points via the
mailing list/discussion group [4]).

Enjoy!

Cheers

Vinay Sajip
Red Dove Consultants Ltd.

[1] https://bitbucket.org/vinay.sajip/python-gnupg
[2] https://pypi.python.org/pypi/python-gnupg/0.4.0
[3] https://bitbucket.org/vinay.sajip/python-gnupg/issues
[4] https://groups.google.com/forum/#!forum/python-gnupg


From saxri89 at gmail.com  Sun Jan 29 14:42:47 2017
From: saxri89 at gmail.com (Xristos Xristoou)
Date: Sun, 29 Jan 2017 11:42:47 -0800 (PST)
Subject: count points where is within the polygons using shapely and fiona
Message-ID: <e1798fb3-056b-44c3-b74d-c96a7345edd8@googlegroups.com>

i tried to count points from the point shapefile where is within in the polygon shapefile but i fail.Maybe my code is complete wrong but i tried.
any idea how to fix my code ?
i want fast method because i have big data features
from shapely.geometry import shape
import fiona

filepath1 = "point.shp"
file1features = []
intersectfeatures_file1 = []
intersectfeatures_file2 = []
count =0
count=count+1
outschema = None
with fiona.collection(filepath1, "r") as input1:
    outschema = input1.schema.copy()
    for p1 in input1:
        file1features.append(p1)

filepath2 = "polygon.shp"
with fiona.collection(filepath2, "r") as input2:
    for p2 in input2:
        for p1 in file1features:
            [count for i in [shape(p1['geometry']).within(shape(p2['geometry']))]]
            if p1 not in intersectfeatures_file1:
                intersectfeatures_file1.append(p1)
            if p2 not in intersectfeatures_file2:
                intersectfeatures_file2.append(p2)

print count
'''
if intersectfeatures_file1:
    outfile = "outputfile1.shp"
    with fiona.collection(outfile, "w", "ESRI Shapefile", outschema) as output:
        for outfeature in intersectfeatures:
            output.write(outfeature)
if intersectfeatures_file2:
    outfile = "outputfile2.shp"
    with fiona.collection(outfile, "w", "ESRI Shapefile", outschema) as output:
        for outfeature in intersectfeatures:
            output.write(outfeature)
'''
on the print count i take 20 times the number 1. after for this count i want to export to new shapefile the polygons where have specific number of points. thnx


From storchaka at gmail.com  Sun Jan 29 16:12:23 2017
From: storchaka at gmail.com (Serhiy Storchaka)
Date: Sun, 29 Jan 2017 23:12:23 +0200
Subject: Is shutil.get_terminal_size useless?
In-Reply-To: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <o6llrh$fjh$2@blaine.gmane.org>

On 28.01.17 10:03, Steve D'Aprano wrote:
> Is shutil.get_terminal_size useless? When, if ever, should I use it in
> preference to the os version? If the shutil version is broken, can it be
> fixed?

Read the history of shutil.get_terminal_size(). All this was discussed.



From jcasale at activenetwerx.com  Sun Jan 29 16:13:32 2017
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Sun, 29 Jan 2017 21:13:32 +0000
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <CAPxRSnYh0E_K-FGVpdhDK2gxCgzEd5b8_-tysQDGY75VSFC+6Q@mail.gmail.com>
References: <CAPxRSnZQP7RqYr9ijuhVWf6QdUWjqS29Rg6OuM5C-vFwZemLWA@mail.gmail.com>
 <CAPxRSnYh0E_K-FGVpdhDK2gxCgzEd5b8_-tysQDGY75VSFC+6Q@mail.gmail.com>
Message-ID: <ad38b3d3415f4294b407d345d8313e6a@activenetwerx.com>

> .NET is a library that can be used from many languages, including Python. 

No.

.NET Core (what the OP asked about which is not .NET) is a cross-platform
framework. Obviously Python and .NET differ in runtime semantics with
respect to the original source code, however they are now roughly equivalent
in that both specifications are cross platform.

I personally like .NET Core a great deal and as the framework matures and
it starts to present all of the .NET APIs, it will become a viable choice on non
Windows platforms.

jlc


From greg.ewing at canterbury.ac.nz  Sun Jan 29 16:54:38 2017
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Mon, 30 Jan 2017 10:54:38 +1300
Subject: How coding in Python is bad for you
In-Reply-To: <588dff48$0$22142$c3e8da3$5496439d@news.astraweb.com>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <87ab542f-0473-40c1-8a56-b41b397fb8b2@googlegroups.com>
 <o6kp86$chs$1@dont-email.me>
 <588dff48$0$22142$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <ef76l0F9d74U1@mid.individual.net>

Steve D'Aprano wrote:

> 5. The statistics module is too slow (and if I ever meet the author, I'll
> give him a kick in the head);

Wow... ad-hominem take to a physical level!

-- 
Greg


From greg.ewing at canterbury.ac.nz  Sun Jan 29 17:00:14 2017
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Mon, 30 Jan 2017 11:00:14 +1300
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <mailman.145.1485724577.2473.python-list@python.org>
References: <CAPxRSnZQP7RqYr9ijuhVWf6QdUWjqS29Rg6OuM5C-vFwZemLWA@mail.gmail.com>
 <CAPxRSnYh0E_K-FGVpdhDK2gxCgzEd5b8_-tysQDGY75VSFC+6Q@mail.gmail.com>
 <ad38b3d3415f4294b407d345d8313e6a@activenetwerx.com>
 <mailman.145.1485724577.2473.python-list@python.org>
Message-ID: <ef76vgF9fabU1@mid.individual.net>

Joseph L. Casale wrote:
>>.NET is a library that can be used from many languages, including Python. 
>
> No.

Yes:

http://pythonnet.sourceforge.net/

"Python for .NET is a package that gives Python programmers nearly seamless 
integration with the .NET Common Language Runtime (CLR) and provides a powerful 
application scripting tool for .NET developers. Using this package you can 
script .NET applications or build entire applications in Python, using .NET 
services and components written in any language that targets the CLR (Managed 
C++, C#, VB, JScript)."

-- 
Greg


From rosuav at gmail.com  Sun Jan 29 17:02:31 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 30 Jan 2017 09:02:31 +1100
Subject: How coding in Python is bad for you
In-Reply-To: <ef76l0F9d74U1@mid.individual.net>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <87ab542f-0473-40c1-8a56-b41b397fb8b2@googlegroups.com>
 <o6kp86$chs$1@dont-email.me>
 <588dff48$0$22142$c3e8da3$5496439d@news.astraweb.com>
 <ef76l0F9d74U1@mid.individual.net>
Message-ID: <CAPTjJmpHaeMmZX-fYe7x2G_3j0zD=j1Q2y0aXfSiXf3GP21nog@mail.gmail.com>

On Mon, Jan 30, 2017 at 8:54 AM, Gregory Ewing
<greg.ewing at canterbury.ac.nz> wrote:
> Steve D'Aprano wrote:
>
>> 5. The statistics module is too slow (and if I ever meet the author, I'll
>> give him a kick in the head);
>
>
> Wow... ad-hominem take to a physical level!

If Steve ever comes face to face with the author of the statistics
module, he should avoid excessive violence, lest he get seven years of
bad luck... for breaking a mirror. :)

ChrisA


From python at deborahswanson.net  Sun Jan 29 17:09:41 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sun, 29 Jan 2017 14:09:41 -0800
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <ad38b3d3415f4294b407d345d8313e6a@activenetwerx.com>
Message-ID: <001801d27a7c$6452b140$27b23dae@sambora>

Joseph L. Casale wrote, on January 29, 2017 1:14 PM
> 
> > .NET is a library that can be used from many languages, including 
> > Python.
> 
> No.
> 
> .NET Core (what the OP asked about which is not .NET) is a 
> cross-platform framework. Obviously Python and .NET differ in 
> runtime semantics with respect to the original source code, 
> however they are now roughly equivalent in that both 
> specifications are cross platform.
> 
> I personally like .NET Core a great deal and as the framework 
> matures and it starts to present all of the .NET APIs, it 
> will become a viable choice on non Windows platforms.
> 
> jlc

What .NET APIs are anticipated to be released that aren't on the
official CLI list now:
https://en.wikipedia.org/wiki/List_of_CLI_languages#Current_Languages,
and/or, are .NET supported languages expected to expand beyond the CLI
list?





From python at lucidity.plus.com  Sun Jan 29 18:52:33 2017
From: python at lucidity.plus.com (Erik)
Date: Sun, 29 Jan 2017 23:52:33 +0000
Subject: How coding in Python is bad for you
In-Reply-To: <588dff48$0$22142$c3e8da3$5496439d@news.astraweb.com>
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <87ab542f-0473-40c1-8a56-b41b397fb8b2@googlegroups.com>
 <o6kp86$chs$1@dont-email.me>
 <588dff48$0$22142$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <00e3f05e-86b4-ea26-7211-39bebc6b4afe@lucidity.plus.com>

On 29/01/17 14:42, Steve D'Aprano wrote:
> 1. for...else is misspelled, and should be for...then;
>
> 2. Same for while...else;

I don't think I'll ever agree with you on this one.

"then", to me, implies the code following it is always executed.
"else" implies it's conditional.

In those constructs it's conditional and therefore, to me, "else" is a 
better reminder of that.

It would be even better if it was "else if not break:" to make the 
meaning clearer. I would agree that it would be even better than that if 
it was "then if not break:" (apart from needing the new keyword ;)), as 
then the conditional aspect is explicit.

E.


From pkpearson at nowhere.invalid  Sun Jan 29 20:06:24 2017
From: pkpearson at nowhere.invalid (Peter Pearson)
Date: 30 Jan 2017 01:06:24 GMT
Subject: count points where is within the polygons using shapely and fiona
References: <e1798fb3-056b-44c3-b74d-c96a7345edd8@googlegroups.com>
Message-ID: <ef7hsgFbb5hU1@mid.individual.net>

On Sun, 29 Jan 2017 11:42:47 -0800 (PST), Xristos Xristoou wrote:
> i tried to count points from the point shapefile where is within in
> the polygon shapefile but i fail.Maybe my code is complete wrong but i
> tried.
> any idea how to fix my code ?
> i want fast method because i have big data features
> from shapely.geometry import shape
> import fiona
>
> filepath1 = "point.shp"
> file1features = []
> intersectfeatures_file1 = []
> intersectfeatures_file2 = []
> count =0
> count=count+1

This is an illogical place to increment count.

> outschema = None
> with fiona.collection(filepath1, "r") as input1:
>     outschema = input1.schema.copy()
>     for p1 in input1:
>         file1features.append(p1)

I believe you could also say file1features = list(input1).


> filepath2 = "polygon.shp"
> with fiona.collection(filepath2, "r") as input2:
>     for p2 in input2:
>         for p1 in file1features:
>             [count for i in [shape(p1['geometry']).within(shape(p2['geometry']))]]

The above line produces a list that is discarded because it is not
assigned any name.

>             if p1 not in intersectfeatures_file1:
>                 intersectfeatures_file1.append(p1)
>             if p2 not in intersectfeatures_file2:
>                 intersectfeatures_file2.append(p2)
>
> print count

> '''
> if intersectfeatures_file1:
>     outfile = "outputfile1.shp"
>     with fiona.collection(outfile, "w", "ESRI Shapefile", outschema) as output:
>         for outfeature in intersectfeatures:
>             output.write(outfeature)
> if intersectfeatures_file2:
>     outfile = "outputfile2.shp"
>     with fiona.collection(outfile, "w", "ESRI Shapefile", outschema) as output:
>         for outfeature in intersectfeatures:
>             output.write(outfeature)
> '''

The above lines between triple quotes should have been omitted
from this post.

> on the print count i take 20 times the number 1. after for this count i want to export to new shapefile the polygons where have specific number of points. thnx


-- 
To email me, substitute nowhere->runbox, invalid->com.


From steve+python at pearwood.info  Sun Jan 29 21:14:30 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Mon, 30 Jan 2017 13:14:30 +1100
Subject: How coding in Python is bad for you
References: <355c105c-d51a-4c66-be66-dde41cba20c8@googlegroups.com>
 <87ab542f-0473-40c1-8a56-b41b397fb8b2@googlegroups.com>
 <o6kp86$chs$1@dont-email.me>
 <588dff48$0$22142$c3e8da3$5496439d@news.astraweb.com>
 <00e3f05e-86b4-ea26-7211-39bebc6b4afe@lucidity.plus.com>
 <mailman.148.1485734143.2473.python-list@python.org>
Message-ID: <588ea186$0$22140$c3e8da3$5496439d@news.astraweb.com>

On Mon, 30 Jan 2017 10:52 am, Erik wrote:

> On 29/01/17 14:42, Steve D'Aprano wrote:
>> 1. for...else is misspelled, and should be for...then;
>>
>> 2. Same for while...else;
> 
> I don't think I'll ever agree with you on this one.
> 
> "then", to me, implies the code following it is always executed.
> "else" implies it's conditional.
> 
> In those constructs it's conditional and therefore, to me, "else" is a
> better reminder of that.

But it isn't conditional. When the code reaches the end of the for/while
block, the else block is ALWAYS executed. Unconditionally.

The only way to skip the else block is to avoid reaching the end of the
for/while block: raise, break or return out of the body of the block.


> It would be even better if it was "else if not break:" to make the
> meaning clearer.

break is not the only way to exit the for loop.


> I would agree that it would be even better than that if 
> it was "then if not break:" (apart from needing the new keyword ;)), as
> then the conditional aspect is explicit.

But it isn't conditional. Your syntax implies that the interpreter keeps
some sort of flag did_we_reach_the_end_of_the_loop_without_break or
something, and then it checks the state of that flag. There is no such
flag. If I remember correctly, that last time this came up here was because
somebody asked how they could read the value of that flag, instead of
setting their own:

for x in seq:
    ...
if not did_we_reach_the_end_of_the_loop_without_break:
    print("break")


They hoped to use the same flag the for-loop used.

But if you use the dis module to decompile the CPython byte-code you will
see that there is no such flag. Code like this:

for i in seq:
    break
else:
    foo
bar

compiles to something like this (results may vary according to the version
of Python):


py> import dis
py> code = compile("""
... for i in seq:
...     break
... else:
...     foo
... bar
... """, "", "exec")
py> dis.dis(code)
  2           0 SETUP_LOOP              19 (to 22)
              3 LOAD_NAME                0 (seq)
              6 GET_ITER
        >>    7 FOR_ITER                 7 (to 17)
             10 STORE_NAME               1 (i)

  3          13 BREAK_LOOP
             14 JUMP_ABSOLUTE            7
        >>   17 POP_BLOCK

  5          18 LOAD_NAME                2 (foo)
             21 POP_TOP

  6     >>   22 LOAD_NAME                3 (bar)
             25 POP_TOP
             26 LOAD_CONST               0 (None)
             29 RETURN_VALUE


Not a single condition to be seen, anywhere. Its all unconditional jumps.

To anticipate a possible objection: it is possible that the FOR_ITER
bytecode is implemented with a conditional test, but even so, all that
tests for is whether to enter the main body of the for-loop (10
STORE_NAME ...) or jump to (18 LOAD_NAME ...).

If you remove the break completely, or replace it with raise or (in a
function) return, and you'll see the same structure to the code: for loops
run the main body of the loop, then unconditionally run the else block,
then unconditionally exit the loop and continue on with the rest of the
program. To avoid the else block, you have to jump out of the entire
for-loop.


-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From steve+python at pearwood.info  Sun Jan 29 21:16:38 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Mon, 30 Jan 2017 13:16:38 +1100
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <o6llrh$fjh$2@blaine.gmane.org>
 <mailman.144.1485724513.2473.python-list@python.org>
Message-ID: <588ea206$0$22140$c3e8da3$5496439d@news.astraweb.com>

On Mon, 30 Jan 2017 08:12 am, Serhiy Storchaka wrote:

> On 28.01.17 10:03, Steve D'Aprano wrote:
>> Is shutil.get_terminal_size useless? When, if ever, should I use it in
>> preference to the os version? If the shutil version is broken, can it be
>> fixed?
> 
> Read the history of shutil.get_terminal_size(). All this was discussed.

Where?



-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From steve+python at pearwood.info  Sun Jan 29 21:49:43 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Mon, 30 Jan 2017 13:49:43 +1100
Subject: Rename file without overwriting existing files
Message-ID: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>

This code contains a Time Of Check to Time Of Use bug:

    if os.path.exists(destination)
        raise ValueError('destination already exists')
    os.rename(oldname, destination)


In the microsecond between checking for the existence of the destination and
actually doing the rename, it is possible that another process may create
the destination, resulting in data loss.

Apart from keeping my fingers crossed, how should I fix this TOCTOU bug?



-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From eryksun at gmail.com  Sun Jan 29 21:51:14 2017
From: eryksun at gmail.com (eryk sun)
Date: Mon, 30 Jan 2017 02:51:14 +0000
Subject: Is shutil.get_terminal_size useless?
In-Reply-To: <588ea206$0$22140$c3e8da3$5496439d@news.astraweb.com>
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <o6llrh$fjh$2@blaine.gmane.org>
 <mailman.144.1485724513.2473.python-list@python.org>
 <588ea206$0$22140$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CACL+1at8tubBX0O+qLGxZLwUbp0Dri6+-X-CwL6f_sZb6UPCdQ@mail.gmail.com>

On Mon, Jan 30, 2017 at 2:16 AM, Steve D'Aprano
<steve+python at pearwood.info> wrote:
> On Mon, 30 Jan 2017 08:12 am, Serhiy Storchaka wrote:
>
>> On 28.01.17 10:03, Steve D'Aprano wrote:
>>> Is shutil.get_terminal_size useless? When, if ever, should I use it in
>>> preference to the os version? If the shutil version is broken, can it be
>>> fixed?
>>
>> Read the history of shutil.get_terminal_size(). All this was discussed.
>
> Where?

See issue 13609:
http://bugs.python.org/issue13609


From rosuav at gmail.com  Sun Jan 29 22:27:08 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 30 Jan 2017 14:27:08 +1100
Subject: Rename file without overwriting existing files
In-Reply-To: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmpKW2rbmyM83UDM+8bV5bx5XbebKiW+9aEKC4wRkCSRuw@mail.gmail.com>

On Mon, Jan 30, 2017 at 1:49 PM, Steve D'Aprano
<steve+python at pearwood.info> wrote:
> This code contains a Time Of Check to Time Of Use bug:
>
>     if os.path.exists(destination)
>         raise ValueError('destination already exists')
>     os.rename(oldname, destination)
>
>
> In the microsecond between checking for the existence of the destination and
> actually doing the rename, it is possible that another process may create
> the destination, resulting in data loss.
>
> Apart from keeping my fingers crossed, how should I fix this TOCTOU bug?

The Linux kernel (sorry, I don't know about others) provides a
renameat2() system call that has the option of failing if the
destination exists. However, I can't currently see any way to call
that from CPython. Seems like an excellent feature request - another
keyword-only argument for os.rename(), like the directory file
descriptors.

ChrisA


From python at mrabarnett.plus.com  Sun Jan 29 22:45:20 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Mon, 30 Jan 2017 03:45:20 +0000
Subject: Rename file without overwriting existing files
In-Reply-To: <CAPTjJmpKW2rbmyM83UDM+8bV5bx5XbebKiW+9aEKC4wRkCSRuw@mail.gmail.com>
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmpKW2rbmyM83UDM+8bV5bx5XbebKiW+9aEKC4wRkCSRuw@mail.gmail.com>
Message-ID: <42cccb97-f771-9e65-3b8d-4fc01cab3cd1@mrabarnett.plus.com>

On 2017-01-30 03:27, Chris Angelico wrote:
> On Mon, Jan 30, 2017 at 1:49 PM, Steve D'Aprano
> <steve+python at pearwood.info> wrote:
>> This code contains a Time Of Check to Time Of Use bug:
>>
>>     if os.path.exists(destination)
>>         raise ValueError('destination already exists')
>>     os.rename(oldname, destination)
>>
>>
>> In the microsecond between checking for the existence of the destination and
>> actually doing the rename, it is possible that another process may create
>> the destination, resulting in data loss.
>>
>> Apart from keeping my fingers crossed, how should I fix this TOCTOU bug?
>
> The Linux kernel (sorry, I don't know about others) provides a
> renameat2() system call that has the option of failing if the
> destination exists. However, I can't currently see any way to call
> that from CPython. Seems like an excellent feature request - another
> keyword-only argument for os.rename(), like the directory file
> descriptors.
>
On Windows it raises FileExistsError if the destination already exists.

shutil.move, on the other hand, replaces if the destination already exists.



From cs at zip.com.au  Sun Jan 29 23:33:03 2017
From: cs at zip.com.au (Cameron Simpson)
Date: Mon, 30 Jan 2017 15:33:03 +1100
Subject: Rename file without overwriting existing files
In-Reply-To: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <20170130043303.GA78047@cskk.homeip.net>

On 30Jan2017 13:49, Steve D'Aprano <steve+python at pearwood.info> wrote:
>This code contains a Time Of Check to Time Of Use bug:
>
>    if os.path.exists(destination)
>        raise ValueError('destination already exists')
>    os.rename(oldname, destination)
>
>
>In the microsecond between checking for the existence of the destination and
>actually doing the rename, it is possible that another process may create
>the destination, resulting in data loss.
>
>Apart from keeping my fingers crossed, how should I fix this TOCTOU bug?

For files this is a problem at the Python level. At the UNIX level you can play 
neat games with open(2) and the various O_* modes.

however, with directories things are more cut and dry. Do you have much freedom 
here? What's the wider context of the question?

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


From Irv at furrypants.com  Mon Jan 30 00:03:33 2017
From: Irv at furrypants.com (Irv Kalb)
Date: Sun, 29 Jan 2017 21:03:33 -0800
Subject: Overriding True and False ?
Message-ID: <3F8981B9-4D4B-41B0-A864-24388A35F5FD@furrypants.com>

I teach intro to programming using Python.  In my first assignment, students are asked to assign variables of different types and print out the values.  

One student (who really did not understand Booleans) turned in the following for his/her interpretation of Booleans (Python 2.7):

True = 'shadow'
False = 'light'
print "If the sun is behind a cloud, there is", True
print "If it is a clear day, there is", False

And it printed:

If the sun is behind a cloud, there is shadow
If it is a clear day, there is light


It seems very odd that Python allows you to override the values of True and False.  In the code, True and False were clearly recognized as keywords as they were colored purple.  But there was no error message.

You cannot assign new values to other keywords.  Simple tests of things like:

for = 5

while = 2

not = 3

As expected, all result in SyntaxError: invalid syntax.  Why would Python allow you to override the values of True and False?  I wonder if this is some sort of historical thing as these are the only keywords besides None that are uppercased.  This line:

None = 5

Even gives a special SyntaxError: cannot assign to None

Just curious,

Irv




From inyeol.lee at gmail.com  Mon Jan 30 00:24:07 2017
From: inyeol.lee at gmail.com (inyeol.lee at gmail.com)
Date: Sun, 29 Jan 2017 21:24:07 -0800 (PST)
Subject: GeneratorExit masks StopIteration?
Message-ID: <56c5f0c3-cfc9-4555-8fd6-a23f4bc5ff32@googlegroups.com>

Does generator.close() prevent raising StopIteration?

I'm trying to get the return value from coroutine after terminating it.
Here is simple test code:

$ python3
Python 3.6.0 (default, Dec 23 2016, 12:50:55) 
[GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.38)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> def cor():
...   try:
...     item = yield
...   except GeneratorExit:
...     return 1
... 
>>> c = cor()
>>> next(c)
>>> c.close()
>>>

I was expecting StopIteration from c.close() call, but Python 3.6 doesn't raise any.
Is this behavior expected? I couldn't find any reference regarding GeneratorExit and StopIteration interaction.


From steve+comp.lang.python at pearwood.info  Mon Jan 30 00:37:21 2017
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Mon, 30 Jan 2017 16:37:21 +1100
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <o6llrh$fjh$2@blaine.gmane.org>
 <mailman.144.1485724513.2473.python-list@python.org>
Message-ID: <588ed113$0$1519$c3e8da3$5496439d@news.astraweb.com>

On Monday 30 January 2017 08:12, Serhiy Storchaka wrote:

> On 28.01.17 10:03, Steve D'Aprano wrote:
>> Is shutil.get_terminal_size useless? When, if ever, should I use it in
>> preference to the os version? If the shutil version is broken, can it be
>> fixed?
> 
> Read the history of shutil.get_terminal_size(). All this was discussed.


Yes, it was discussed, but not resolved: Antoine Pitrou just closed the task 
and declared it done, without resolving the failures I am talking about here.

http://bugs.python.org/issue13609

(Thanks Eryk Sun for the link.)



-- 
Steven
"Ever since I learned about confirmation bias, I've been seeing 
it everywhere." - Jon Ronson



From rosuav at gmail.com  Mon Jan 30 00:54:31 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 30 Jan 2017 16:54:31 +1100
Subject: GeneratorExit masks StopIteration?
In-Reply-To: <56c5f0c3-cfc9-4555-8fd6-a23f4bc5ff32@googlegroups.com>
References: <56c5f0c3-cfc9-4555-8fd6-a23f4bc5ff32@googlegroups.com>
Message-ID: <CAPTjJmoo5fcY99dnKgZ4wCp7GPKf89ZR17nuEKR=0jyJ-G6d2w@mail.gmail.com>

On Mon, Jan 30, 2017 at 4:24 PM,  <inyeol.lee at gmail.com> wrote:
> I was expecting StopIteration from c.close() call, but Python 3.6 doesn't raise any.
> Is this behavior expected? I couldn't find any reference regarding GeneratorExit and StopIteration interaction.

When you close() a generator, it raises GeneratorExit into it, and
then silences any StopIteration or GeneratorExit that comes out of it.
If you need different behaviour, what you could do is explicitly
throw() into it:

>>> c.throw(GeneratorExit)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
StopIteration: 1

which you'd obviously want to wrap in try/except, but at that point,
you have the result.

Maybe this could be a feature request - that generator.close() returns
the return value of the generator (or None if the GeneratorExit comes
out)?

ChrisA


From best_lay at yahoo.com  Mon Jan 30 00:59:19 2017
From: best_lay at yahoo.com (Wildman)
Date: Sun, 29 Jan 2017 23:59:19 -0600
Subject: Is shutil.get_terminal_size useless?
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <bbudnYYOcdWqSxPFnZ2dnUU7-YudnZ2d@giganews.com>

On Sat, 28 Jan 2017 19:03:42 +1100, Steve D'Aprano wrote:

> shutil.get_terminal_size returns the wrong values when you pipe your output
> to another process, even it you do so in a terminal. Consider this script:
> 
> 
> import os
> import shutil
> print('shutil:', shutil.get_terminal_size(fallback=(999, 999)))
> print('os:', os.get_terminal_size(0))
> 
> 
> That uses two different methods to get the terminal size. If I run that in a
> terminal in the normal way, it works fine, returning the correct size for
> my terminal:
> 
> 
> [steve at ando ~]$ python3.5 test_gts.py
> shutil: os.terminal_size(columns=116, lines=29)
> os: os.terminal_size(columns=116, lines=29)
> 
> 
> But if I pipe the output to something else, the shutil version fails to
> determine the correct terminal size, and falls back on the default:
> 
> 
> [steve at ando ~]$ python3.5 test_gts.py | cat
> shutil: os.terminal_size(columns=999, lines=999)
> os: os.terminal_size(columns=116, lines=29)
> 
> 
> while the os version gives the correct result.
> 
> Is shutil.get_terminal_size useless? When, if ever, should I use it in
> preference to the os version? If the shutil version is broken, can it be
> fixed?
> 
> 
> Thanks to Bernardas Ali?auskas:
> 
> http://granitosaurus.rocks/getting-terminal-size.html

I can suggest a third approach to try but I have not tried
piping it.  YMMV.

import fcntl
import os
import struct
import termios

tty = os.open(os.ctermid(), os.O_RDONLY)
ts = struct.unpack("hh", fcntl.ioctl(tty, termios.TIOCGWINSZ, "1234"))
os.close(tty)
columns = ts[1]
rows = ts[0]
print(str(columns) + "x" + str(rows))

-- 
<Wildman> GNU/Linux user #557453
The cow died so I don't need your bull!


From python at deborahswanson.net  Mon Jan 30 01:09:07 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sun, 29 Jan 2017 22:09:07 -0800
Subject: GeneratorExit masks StopIteration?
In-Reply-To: <56c5f0c3-cfc9-4555-8fd6-a23f4bc5ff32@googlegroups.com>
Message-ID: <002a01d27abf$5e8a2660$27b23dae@sambora>

inyeol.lee at gmail.com wrote, on January 29, 2017 9:24 PM

> 
> Does generator.close() prevent raising StopIteration?
> 
> I'm trying to get the return value from coroutine after 
> terminating it. Here is simple test code:
> 
> $ python3
> Python 3.6.0 (default, Dec 23 2016, 12:50:55) 
> [GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.38)] on 
> darwin Type "help", "copyright", "credits" or "license" for 
> more information.
> >>> def cor():
> ...   try:
> ...     item = yield
> ...   except GeneratorExit:
> ...     return 1
> ... 
> >>> c = cor()
> >>> next(c)
> >>> c.close()
> >>>
> 
> I was expecting StopIteration from c.close() call, but Python 
> 3.6 doesn't raise any. Is this behavior expected? I couldn't 
> find any reference regarding GeneratorExit and StopIteration 
> interaction.

Use except StopIteration:

(Not sure what generator.close() should do, or if GeneratorExit is any
kind of equivalent, but StopIteration works. I'm less familiar with
Python 2.)

Python 3.4.3 |Anaconda 2.3.0 (32-bit)| (default, Mar  6 2015, 12:08:17)
[MSC v.1600 32 bit (Intel)] on win32
Type "copyright", "credits" or "license()" for more information.
>>> help(generator.close)
Traceback (most recent call last):
  File "<pyshell#0>", line 1, in <module>
    help(generator.close)
NameError: name 'generator' is not defined

So at the very least, generator needs to be defined, if it's possible to
define or import it in Python 3. Probably not.

In Python 2, GeneratorExit is raised when the generator's close() method
is called. But in my quick search, I couldn't find GeneratorExit in
Python 3, or any note that it had been dropped, but it's a good guess
that it was dropped. It's redundant with StopIteration.

I always use StopIteration. It works in all Python versions.



From hmmeeranrizvi18 at gmail.com  Mon Jan 30 01:32:31 2017
From: hmmeeranrizvi18 at gmail.com (hmmeeranrizvi18 at gmail.com)
Date: Sun, 29 Jan 2017 22:32:31 -0800 (PST)
Subject: Display a label while pressing the button in my GUI
Message-ID: <dff79ff1-8136-491b-a903-5c9a91ce5e0c@googlegroups.com>

Hello Guys,
Here i am creating a GUI which will act as a search engine that will find the results from the browser and save the results as a xls file.
When i typed something in my search box and click the (GO)button.It should display search in progress.when the file is saved it should display done.
How to do that?
My button gets hung for a seconds.We should give any timeout for that?

Here is my script
<python>
from Tkinter import *
import mechanize
def clear_search(event):
    search.delete(0,END)
obj = Tk()
Label = Label(obj,text="Top Findings:",font="-weight bold")
search = Entry(obj,width=100)
search.insert(0, "Enter the value to search")
search.bind("<Button-1>", clear_search)
def fun():
    new = search.get()
    url = "http://duckduckgo.com/html"
    br = mechanize.Browser()
    br.set_handle_robots(False)
    br.open(url)
    br.select_form(name="x")
    br["q"] = str(new)
    res = br.submit()
    content = res.read()
    with open("result1.xls", "w") as f:
        f.write(content)
fun()
Go = Button(obj,text="GO",width=5,command=fun)
Label.pack()
search.pack()
Go.pack()
mainloop()
</python>


From inyeol.lee at gmail.com  Mon Jan 30 01:38:26 2017
From: inyeol.lee at gmail.com (inyeol.lee at gmail.com)
Date: Sun, 29 Jan 2017 22:38:26 -0800 (PST)
Subject: GeneratorExit masks StopIteration?
In-Reply-To: <mailman.153.1485755674.2473.python-list@python.org>
References: <56c5f0c3-cfc9-4555-8fd6-a23f4bc5ff32@googlegroups.com>
 <CAPTjJmoo5fcY99dnKgZ4wCp7GPKf89ZR17nuEKR=0jyJ-G6d2w@mail.gmail.com>
 <mailman.153.1485755674.2473.python-list@python.org>
Message-ID: <ff98fc74-d95d-49f5-a561-6eec2352f3d0@googlegroups.com>

On Sunday, January 29, 2017 at 9:54:44 PM UTC-8, Chris Angelico wrote:
> ...
> When you close() a generator, it raises GeneratorExit into it, and
> then silences any StopIteration or GeneratorExit that comes out of it.

Chris,
Thanks for the info. Is this (GenExit silencing StopIteration) documented somewhere?
I was suspecting this but couldn't find any reference.



From rosuav at gmail.com  Mon Jan 30 01:46:55 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 30 Jan 2017 17:46:55 +1100
Subject: GeneratorExit masks StopIteration?
In-Reply-To: <ff98fc74-d95d-49f5-a561-6eec2352f3d0@googlegroups.com>
References: <56c5f0c3-cfc9-4555-8fd6-a23f4bc5ff32@googlegroups.com>
 <CAPTjJmoo5fcY99dnKgZ4wCp7GPKf89ZR17nuEKR=0jyJ-G6d2w@mail.gmail.com>
 <mailman.153.1485755674.2473.python-list@python.org>
 <ff98fc74-d95d-49f5-a561-6eec2352f3d0@googlegroups.com>
Message-ID: <CAPTjJmpzPK97VsE_nCp9dj4FBcF+4muSTX2QWK2KHX74XwEruw@mail.gmail.com>

On Mon, Jan 30, 2017 at 5:38 PM,  <inyeol.lee at gmail.com> wrote:
> On Sunday, January 29, 2017 at 9:54:44 PM UTC-8, Chris Angelico wrote:
>> ...
>> When you close() a generator, it raises GeneratorExit into it, and
>> then silences any StopIteration or GeneratorExit that comes out of it.
>
> Chris,
> Thanks for the info. Is this (GenExit silencing StopIteration) documented somewhere?
> I was suspecting this but couldn't find any reference.

Actually..... think this might be incorrect. I didn't look in the
docs, I looked in the source code, so my information is guaranteed
accurate; this is where I would expect the information to be:

https://docs.python.org/3/reference/expressions.html#generator.close

As a general rule, a generator shouldn't be leaking StopIteration. In
a future version of Python, this will trigger RuntimeError. (You can
get that behaviour in 3.6 with a future import, too.) So what this
really means is that close() will suppress any GeneratorExit, or the
generator returning, both of which are normal occurrences. The only
significant thing is that the generator's return value could usefully
be propagated out of close().

ChrisA


From inyeol.lee at gmail.com  Mon Jan 30 02:17:09 2017
From: inyeol.lee at gmail.com (inyeol.lee at gmail.com)
Date: Sun, 29 Jan 2017 23:17:09 -0800 (PST)
Subject: GeneratorExit masks StopIteration?
In-Reply-To: <mailman.155.1485758818.2473.python-list@python.org>
References: <56c5f0c3-cfc9-4555-8fd6-a23f4bc5ff32@googlegroups.com>
 <CAPTjJmoo5fcY99dnKgZ4wCp7GPKf89ZR17nuEKR=0jyJ-G6d2w@mail.gmail.com>
 <mailman.153.1485755674.2473.python-list@python.org>
 <ff98fc74-d95d-49f5-a561-6eec2352f3d0@googlegroups.com>
 <CAPTjJmpzPK97VsE_nCp9dj4FBcF+4muSTX2QWK2KHX74XwEruw@mail.gmail.com>
 <mailman.155.1485758818.2473.python-list@python.org>
Message-ID: <8683ea83-1c3b-44d0-a7d4-764743c7e33a@googlegroups.com>

On Sunday, January 29, 2017 at 10:47:09 PM UTC-8, Chris Angelico wrote:
> On Mon, Jan 30, 2017 at 5:38 PM,  <inyeol.lee at gmail.com> wrote:
> > On Sunday, January 29, 2017 at 9:54:44 PM UTC-8, Chris Angelico wrote:
> >> ...
> >> When you close() a generator, it raises GeneratorExit into it, and
> >> then silences any StopIteration or GeneratorExit that comes out of it.
> >
> > Chris,
> > Thanks for the info. Is this (GenExit silencing StopIteration) documented somewhere?
> > I was suspecting this but couldn't find any reference.
> 
> Actually..... think this might be incorrect. I didn't look in the
> docs, I looked in the source code, so my information is guaranteed
> accurate

I found PEP-342 describes this behavior - silencing other GenExit or StopIteration.

BTW, the reason why I was checking this was to find a solution on how to get return value from coroutine without relying on some sentinel value, something like (not tested):

def accumulator():
  sum = 0
  try:
    while True:
      sum += yield
  except GeneratorExit:
    return sum

Any alternatives? Explicitly throwing GenExit looks like a hack.



From jcasale at activenetwerx.com  Mon Jan 30 02:25:05 2017
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Mon, 30 Jan 2017 07:25:05 +0000
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <001801d27a7c$6452b140$27b23dae@sambora>
References: <ad38b3d3415f4294b407d345d8313e6a@activenetwerx.com>
 <001801d27a7c$6452b140$27b23dae@sambora>
Message-ID: <c828d670c8ed4137924cd3aebe387942@activenetwerx.com>

> What .NET APIs are anticipated to be released that aren't on the
> official CLI list now:
> https://en.wikipedia.org/wiki/List_of_CLI_languages#Current_Languages,
> and/or, are .NET supported languages expected to expand beyond the CLI
> list?

I think this (and the last point) misinterprets the semantics of the OPs post.

.NET Core is not .NET, it's a **multi-platform** framework for a language
syntax specification (c#). It's not an implementation of some API that you
cannleverage in another language specification.

Writing a ctype accessor for a Windows API does not equate to cpp code
that is now magically Python. It means no more than what it is, "a foreign
function library for Python" (https://docs.python.org/3/library/ctypes.html).

.Net Core is fundamentally different and much like Python in the way that
a compiler and runtime for a common language syntax specification has been
written for multiple platforms. So in general, the same Python script could
run on both platforms, and most certainly the same .NET Core source could
compile and run on its supported platforms.

So back to the question, .NET Core is a wip which where applicable will soon
present all the existing .NET APIs, excluding those which are Windows specific
and don't make sense to present on a non-Windows platform like Windows Forms.

jlc


From songofacandy at gmail.com  Mon Jan 30 02:38:31 2017
From: songofacandy at gmail.com (INADA Naoki)
Date: Mon, 30 Jan 2017 16:38:31 +0900
Subject: Overriding True and False ?
In-Reply-To: <3F8981B9-4D4B-41B0-A864-24388A35F5FD@furrypants.com>
References: <3F8981B9-4D4B-41B0-A864-24388A35F5FD@furrypants.com>
Message-ID: <CAEfz+Tw1gAvKqjfBxOw0WiQ0R3_1kkvQFD93zgSCoQEQ+u5-Jw@mail.gmail.com>

It's fixed already in Python 3.
Please use Python 3 when teaching to students.

$ python3
Python 3.6.0 (default, Dec 24 2016, 00:01:50)
[GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.42.1)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> True = "foo"
  File "<stdin>", line 1
SyntaxError: can't assign to keyword


From denis.akhiyarov at gmail.com  Mon Jan 30 02:49:19 2017
From: denis.akhiyarov at gmail.com (denis.akhiyarov at gmail.com)
Date: Sun, 29 Jan 2017 23:49:19 -0800 (PST)
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <ef76vgF9fabU1@mid.individual.net>
References: <CAPxRSnZQP7RqYr9ijuhVWf6QdUWjqS29Rg6OuM5C-vFwZemLWA@mail.gmail.com>
 <CAPxRSnYh0E_K-FGVpdhDK2gxCgzEd5b8_-tysQDGY75VSFC+6Q@mail.gmail.com>
 <ad38b3d3415f4294b407d345d8313e6a@activenetwerx.com>
 <mailman.145.1485724577.2473.python-list@python.org>
 <ef76vgF9fabU1@mid.individual.net>
Message-ID: <7f5e4c86-181b-457a-ab6c-1cea0989aed9@googlegroups.com>

On Sunday, January 29, 2017 at 4:00:27 PM UTC-6, Gregory Ewing wrote:
> Joseph L. Casale wrote:
> >>.NET is a library that can be used from many languages, including Python. 
> >
> > No.
> 
> Yes:
> 
> http://pythonnet.sourceforge.net/
> 
> "Python for .NET is a package that gives Python programmers nearly seamless 
> integration with the .NET Common Language Runtime (CLR) and provides a powerful 
> application scripting tool for .NET developers. Using this package you can 
> script .NET applications or build entire applications in Python, using .NET 
> services and components written in any language that targets the CLR (Managed 
> C++, C#, VB, JScript)."
> 
> -- 
> Greg

This is outdated location. pythonnet (python for .NET) is on GitHub since 2014.

https://github.com/pythonnet/pythonnet

We just released v2.2.2 with Python 3.6 support and transition to MIT license.

Download from PYPI using pip or from Anaconda using conda:

https://pypi.python.org/pypi/pythonnet/2.2.2
https://anaconda.org/pythonnet/pythonnet



From python at deborahswanson.net  Mon Jan 30 02:50:21 2017
From: python at deborahswanson.net (Deborah Swanson)
Date: Sun, 29 Jan 2017 23:50:21 -0800
Subject: Overriding True and False ?
In-Reply-To: <3F8981B9-4D4B-41B0-A864-24388A35F5FD@furrypants.com>
Message-ID: <000a01d27acd$82b3c6f0$27b23dae@sambora>

Irv Kalb wrote, on Sunday, January 29, 2017 9:04 PM
> 
> I teach intro to programming using Python.  In my first 
> assignment, students are asked to assign variables of 
> different types and print out the values.  
> 
> One student (who really did not understand Booleans) turned 
> in the following for his/her interpretation of Booleans (Python 2.7):
> 
> True = 'shadow'
> False = 'light'
> print "If the sun is behind a cloud, there is", True
> print "If it is a clear day, there is", False
> 
> And it printed:
> 
> If the sun is behind a cloud, there is shadow
> If it is a clear day, there is light
> 
> 
> It seems very odd that Python allows you to override the 
> values of True and False.  In the code, True and False were 
> clearly recognized as keywords as they were colored purple.  
> But there was no error message.
> 
> You cannot assign new values to other keywords.  Simple tests 
> of things like:
> 
> for = 5
> 
> while = 2
> 
> not = 3
> 
> As expected, all result in SyntaxError: invalid syntax.  Why 
> would Python allow you to override the values of True and 
> False?  I wonder if this is some sort of historical thing as 
> these are the only keywords besides None that are uppercased. 
>  This line:
> 
> None = 5
> 
> Even gives a special SyntaxError: cannot assign to None
> 
> Just curious,
> 
> Irv

Just guessing, but in the examples you give in Python 2.7, substitute
strings are syntactically correct in print statements, but:

5 in list('abc'):

2 True:

if a 3 b:

would all be syntactical errors.

As is 'None = 5'.

Looks like the moral of the story is that in Python 2.7 you can redefine
keywords, so long as you don't get any syntax errors after (or during)
redefinition.



From ben+python at benfinney.id.au  Mon Jan 30 02:50:56 2017
From: ben+python at benfinney.id.au (Ben Finney)
Date: Mon, 30 Jan 2017 18:50:56 +1100
Subject: Overriding True and False ?
References: <3F8981B9-4D4B-41B0-A864-24388A35F5FD@furrypants.com>
Message-ID: <85zii9t28v.fsf@benfinney.id.au>

Irv Kalb <Irv at furrypants.com> writes:

> I teach intro to programming using Python. [?]

Thank you for teaching Python to beginners!

> It seems very odd that Python allows you to override the values of
> True and False.

Yes, it is. That's why Python 3 forbids it::

    >>> True = "shadow"
      File "<stdin>", line 1
    SyntaxError: can't assign to keyword
    >>> False = "light"
      File "<stdin>", line 1
    SyntaxError: can't assign to keyword

When teaching Python, please do not teach Python 2. Your students should
learn Python 3 first, primarily, and for most of the course.

Python 2 is a legacy that will never gain new features, and will only
slip further behind the current supported Python version. That makes
Python 2 a poor choice for teaching to beginners.

-- 
 \          ?The entertainment industry calls DRM "security" software, |
  `\         because it makes them secure from their customers.? ?Cory |
_o__)                                             Doctorow, 2014-02-05 |
Ben Finney



From rosuav at gmail.com  Mon Jan 30 02:54:28 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 30 Jan 2017 18:54:28 +1100
Subject: Overriding True and False ?
In-Reply-To: <3F8981B9-4D4B-41B0-A864-24388A35F5FD@furrypants.com>
References: <3F8981B9-4D4B-41B0-A864-24388A35F5FD@furrypants.com>
Message-ID: <CAPTjJmrRQ0EEjZ4tvdx0YeNRjZzttovFaXbniekO_txwkvTA7g@mail.gmail.com>

On Mon, Jan 30, 2017 at 4:03 PM, Irv Kalb <Irv at furrypants.com> wrote:
> It seems very odd that Python allows you to override the values of True and False.  In the code, True and False were clearly recognized as keywords as they were colored purple.  But there was no error message.
>
> You cannot assign new values to other keywords.  Simple tests of things like:
>
> for = 5
>
> while = 2
>
> not = 3
>
> As expected, all result in SyntaxError: invalid syntax.  Why would Python allow you to override the values of True and False?  I wonder if this is some sort of historical thing as these are the only keywords besides None that are uppercased.  This line:
>
> None = 5
>
> Even gives a special SyntaxError: cannot assign to None

There are slightly different things going on here. Trying to assign to
a piece of syntax like "while" makes absolutely no sense, but trying
to assign to "None" is structurally sane, yet disallowed. IIRC there's
only one non-assignable name in Python 2 (None), but as mentioned,
Python 3 adds True and False to that. (Interestingly, Ellipsis is not
included in that.)

> I teach intro to programming using Python.

May I please request that you consider teaching Python 3? Python 2
isn't going anywhere (for better or for worse), and Py3 is a superior
language in many ways, not least of which is that it keeps text and
bytes separate, giving text the full power that it should have. For a
beginning programmer, this is very helpful; there's nothing to
un-learn when going international. (There will be new nuances to be
learned, such as RTL text, but nothing to unlearn.) Python 3 also
fixes a number of other problems that Python 2 inherited from C,
making it altogether a better language for teaching with.

ChrisA


From rosuav at gmail.com  Mon Jan 30 02:57:11 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 30 Jan 2017 18:57:11 +1100
Subject: Overriding True and False ?
In-Reply-To: <000a01d27acd$82b3c6f0$27b23dae@sambora>
References: <3F8981B9-4D4B-41B0-A864-24388A35F5FD@furrypants.com>
 <000a01d27acd$82b3c6f0$27b23dae@sambora>
Message-ID: <CAPTjJmpCoSB_vF1TYyygTzatn4S8i30g=DEQjSuFHtAj2ewndw@mail.gmail.com>

On Mon, Jan 30, 2017 at 6:50 PM, Deborah Swanson
<python at deborahswanson.net> wrote:
> Looks like the moral of the story is that in Python 2.7 you can redefine
> keywords, so long as you don't get any syntax errors after (or during)
> redefinition.

The moral is actually that "True" and "False" aren't keywords in Py2.
They're just built-ins. Compare:

rosuav at sikorsky:~$ python3
Python 3.7.0a0 (default:cebc9c7ad195, Jan 24 2017, 06:55:19)
[GCC 6.2.0 20161027] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import dis
>>> dis.dis(lambda: True)
  1           0 LOAD_CONST               1 (True)
              2 RETURN_VALUE
>>>
rosuav at sikorsky:~$ python
Python 2.7.12+ (default, Sep  1 2016, 20:27:38)
[GCC 6.2.0 20160927] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import dis
>>> dis.dis(lambda: True)
  1           0 LOAD_GLOBAL              0 (True)
              3 RETURN_VALUE
>>>

In Python 2, returning "True" involves a name lookup; in Python 3,
it's simply a constant - a literal.

ChrisA


From rosuav at gmail.com  Mon Jan 30 03:00:25 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 30 Jan 2017 19:00:25 +1100
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <c828d670c8ed4137924cd3aebe387942@activenetwerx.com>
References: <ad38b3d3415f4294b407d345d8313e6a@activenetwerx.com>
 <001801d27a7c$6452b140$27b23dae@sambora>
 <c828d670c8ed4137924cd3aebe387942@activenetwerx.com>
Message-ID: <CAPTjJmo3H5gbaTyiM_+wujqYuD0wgud3FLQ33-chJN_jsDtAYA@mail.gmail.com>

On Mon, Jan 30, 2017 at 6:25 PM, Joseph L. Casale
<jcasale at activenetwerx.com> wrote:
> .Net Core is fundamentally different and much like Python in the way that
> a compiler and runtime for a common language syntax specification has been
> written for multiple platforms. So in general, the same Python script could
> run on both platforms, and most certainly the same .NET Core source could
> compile and run on its supported platforms.

What do you mean by "both platforms"? Python scripts already run on
three major operating systems (Win/Lin/Mac) and a good number of
less-popular OSes; a well-written Python script will run in four major
Pythons (CPython, PyPy, Jython, IronPython) and a number of others;
and all manner of CPU architectures and so on.

ChrisA


From __peter__ at web.de  Mon Jan 30 04:31:01 2017
From: __peter__ at web.de (Peter Otten)
Date: Mon, 30 Jan 2017 10:31:01 +0100
Subject: Display a label while pressing the button in my GUI
References: <dff79ff1-8136-491b-a903-5c9a91ce5e0c@googlegroups.com>
Message-ID: <o6n14h$4en$1@blaine.gmane.org>

hmmeeranrizvi18 at gmail.com wrote:

> Hello Guys,
> Here i am creating a GUI which will act as a search engine that will find
> the results from the browser and save the results as a xls file. When i
> typed something in my search box and click the (GO)button.It should
> display search in progress.when the file is saved it should display done.
> How to do that? My button gets hung for a seconds.We should give any
> timeout for that?

Move the actual processing into another thread and have it communicate with 
your GUI through a Queue. Here's a sketch:

import Queue
import threading

from Tkinter import *
import mechanize

def clear_search(event):
    search.delete(0, END)

def start_search():
    thread = threading.Thread(
        target=fun,
        args=(search.get(),)
    )
    thread.setDaemon(True)
    thread.start()
    root.after(100, check_state)

def fun(new):
    queue.put("searching")
    url = "http://duckduckgo.com/html"
    br = mechanize.Browser()
    br.set_handle_robots(False)
    br.open(url)
    br.select_form(name="x")
    br["q"] = str(new)
    res = br.submit()
    queue.put("writing result")
    content = res.read()
    with open("result1.xls", "w") as f:
        f.write(content)
    queue.put("done")

def check_state():
    while True:
        try:
            message = queue.get_nowait()
        except Queue.Empty:
            break
        state_info["text"] = message
        if message == "done":
            return
    root.after(100, check_state)

queue = Queue.Queue()
root = Tk()

top_findings = Label(root, text="Top Findings:", font="-weight bold")
top_findings.pack()

search = Entry(root, width=100)
search.insert(0, "Enter the value to search")

# Did you see Christian Gollwitzer's post?
search.bind("<FocusIn>", clear_search)

search.pack()

go_button = Button(root, text="GO", width=5, command=start_search)
go_button.pack()

state_info = Label(root)
state_info.pack()

root.mainloop()




From steve+python at pearwood.info  Mon Jan 30 05:16:29 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Mon, 30 Jan 2017 21:16:29 +1100
Subject: Rename file without overwriting existing files
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
 <20170130043303.GA78047@cskk.homeip.net>
 <mailman.152.1485750834.2473.python-list@python.org>
Message-ID: <588f127e$0$1586$c3e8da3$5496439d@news.astraweb.com>

On Mon, 30 Jan 2017 03:33 pm, Cameron Simpson wrote:

> On 30Jan2017 13:49, Steve D'Aprano <steve+python at pearwood.info> wrote:
>>This code contains a Time Of Check to Time Of Use bug:
>>
>>    if os.path.exists(destination)
>>        raise ValueError('destination already exists')
>>    os.rename(oldname, destination)
>>
>>
>>In the microsecond between checking for the existence of the destination
>>and actually doing the rename, it is possible that another process may
>>create the destination, resulting in data loss.
>>
>>Apart from keeping my fingers crossed, how should I fix this TOCTOU bug?
> 
> For files this is a problem at the Python level. At the UNIX level you can
> play neat games with open(2) and the various O_* modes.
> 
> however, with directories things are more cut and dry. Do you have much
> freedom here? What's the wider context of the question?

The wider context is that I'm taking from 1 to <arbitrarily huge number>
path names to existing files as arguments, and for each path name I
transfer the file name part (but not the directory part) and then rename
the file. For example:

foo/bar/baz/spam.txt

may be renamed to:

foo/bar/baz/ham.txt

but only provided ham.txt doesn't already exist.




-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From p.f.moore at gmail.com  Mon Jan 30 05:31:59 2017
From: p.f.moore at gmail.com (Paul Moore)
Date: Mon, 30 Jan 2017 02:31:59 -0800 (PST)
Subject: Is shutil.get_terminal_size useless?
In-Reply-To: <588ed113$0$1519$c3e8da3$5496439d@news.astraweb.com>
References: <588c505f$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <o6llrh$fjh$2@blaine.gmane.org>
 <mailman.144.1485724513.2473.python-list@python.org>
 <588ed113$0$1519$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <cc9d3740-f79c-4eea-b041-81a83e894961@googlegroups.com>

On Monday, 30 January 2017 05:37:32 UTC, Steven D'Aprano  wrote:
> On Monday 30 January 2017 08:12, Serhiy Storchaka wrote:
> 
> > On 28.01.17 10:03, Steve D'Aprano wrote:
> >> Is shutil.get_terminal_size useless? When, if ever, should I use it in
> >> preference to the os version? If the shutil version is broken, can it be
> >> fixed?
> > 
> > Read the history of shutil.get_terminal_size(). All this was discussed.
> 
> 
> Yes, it was discussed, but not resolved: Antoine Pitrou just closed the task 
> and declared it done, without resolving the failures I am talking about here.
> 
> http://bugs.python.org/issue13609
> 
> (Thanks Eryk Sun for the link.)


Looks like it was closed with the comment "If you want further features, please open a new issue". It sounds to me like os.get_terminal_size() does what you want, and others find the shutil version useful. But if you have a use case for the shutil version that needs a change in its behaviour, I guess you should open an issue for that.

The docs on shutil.get_terminal_size seem pretty clear on what it does (whether you agree with the behaviour or not), so I don't think there's much benefit to proposing changes to the docs alone.

Paul


From __peter__ at web.de  Mon Jan 30 05:39:49 2017
From: __peter__ at web.de (Peter Otten)
Date: Mon, 30 Jan 2017 11:39:49 +0100
Subject: Rename file without overwriting existing files
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
 <20170130043303.GA78047@cskk.homeip.net>
 <mailman.152.1485750834.2473.python-list@python.org>
 <588f127e$0$1586$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <o6n55h$9of$1@blaine.gmane.org>

Steve D'Aprano wrote:

> On Mon, 30 Jan 2017 03:33 pm, Cameron Simpson wrote:
> 
>> On 30Jan2017 13:49, Steve D'Aprano <steve+python at pearwood.info> wrote:
>>>This code contains a Time Of Check to Time Of Use bug:
>>>
>>>    if os.path.exists(destination)
>>>        raise ValueError('destination already exists')
>>>    os.rename(oldname, destination)
>>>
>>>
>>>In the microsecond between checking for the existence of the destination
>>>and actually doing the rename, it is possible that another process may
>>>create the destination, resulting in data loss.
>>>
>>>Apart from keeping my fingers crossed, how should I fix this TOCTOU bug?
>> 
>> For files this is a problem at the Python level. At the UNIX level you
>> can play neat games with open(2) and the various O_* modes.
>> 
>> however, with directories things are more cut and dry. Do you have much
>> freedom here? What's the wider context of the question?
> 
> The wider context is that I'm taking from 1 to <arbitrarily huge number>
> path names to existing files as arguments, and for each path name I
> transfer the file name part (but not the directory part) and then rename
> the file. For example:
> 
> foo/bar/baz/spam.txt
> 
> may be renamed to:
> 
> foo/bar/baz/ham.txt
> 
> but only provided ham.txt doesn't already exist.

Google finds

http://stackoverflow.com/questions/3222341/how-to-rename-without-race-conditions

and from a quick test it appears to work on Linux:

$ echo foo > foo
$ echo bar > bar
$ python3
Python 3.4.3 (default, Nov 17 2016, 01:08:31) 
[GCC 4.8.4] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>> def rename(source, dest):
...     os.link(source, dest)
...     os.unlink(source)
... 
>>> rename("foo", "baz")
>>> os.listdir()
['bar', 'baz']
>>> rename("bar", "baz")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 2, in rename
FileExistsError: [Errno 17] File exists: 'bar' -> 'baz'




From jussi.piitulainen at helsinki.fi  Mon Jan 30 05:55:45 2017
From: jussi.piitulainen at helsinki.fi (Jussi Piitulainen)
Date: Mon, 30 Jan 2017 12:55:45 +0200
Subject: Rename file without overwriting existing files
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
 <20170130043303.GA78047@cskk.homeip.net>
 <mailman.152.1485750834.2473.python-list@python.org>
 <588f127e$0$1586$c3e8da3$5496439d@news.astraweb.com>
 <o6n55h$9of$1@blaine.gmane.org>
 <mailman.165.1485772799.2473.python-list@python.org>
Message-ID: <lf5efzkn7f2.fsf@ling.helsinki.fi>

Peter Otten writes:

> Steve D'Aprano wrote:
>
>> On Mon, 30 Jan 2017 03:33 pm, Cameron Simpson wrote:
>> 
>>> On 30Jan2017 13:49, Steve D'Aprano <steve+python at pearwood.info> wrote:
>>>>This code contains a Time Of Check to Time Of Use bug:
>>>>
>>>>    if os.path.exists(destination)
>>>>        raise ValueError('destination already exists')
>>>>    os.rename(oldname, destination)
>>>>
>>>>
>>>>In the microsecond between checking for the existence of the destination
>>>>and actually doing the rename, it is possible that another process may
>>>>create the destination, resulting in data loss.
>>>>
>>>>Apart from keeping my fingers crossed, how should I fix this TOCTOU bug?
>>> 
>>> For files this is a problem at the Python level. At the UNIX level you
>>> can play neat games with open(2) and the various O_* modes.
>>> 
>>> however, with directories things are more cut and dry. Do you have much
>>> freedom here? What's the wider context of the question?
>> 
>> The wider context is that I'm taking from 1 to <arbitrarily huge number>
>> path names to existing files as arguments, and for each path name I
>> transfer the file name part (but not the directory part) and then rename
>> the file. For example:
>> 
>> foo/bar/baz/spam.txt
>> 
>> may be renamed to:
>> 
>> foo/bar/baz/ham.txt
>> 
>> but only provided ham.txt doesn't already exist.
>
> Google finds
>
> http://stackoverflow.com/questions/3222341/how-to-rename-without-race-conditions
>
> and from a quick test it appears to work on Linux:

It doesn't seem to be documented. I looked at help(os.link) on Python
3.4 and the corresponding current library documentation on the web. I
saw no mention of what happens when dst exists already.

Also, creating a hard link doesn't seem to work between different file
systems, which may well be relevant to Steve's case. I get:

    OSError: [Errno 18] Invalid cross-device link: [snip]

And that also is not mentioned in the docs.


From wolfgang.maier at biologie.uni-freiburg.de  Mon Jan 30 06:24:58 2017
From: wolfgang.maier at biologie.uni-freiburg.de (Wolfgang Maier)
Date: Mon, 30 Jan 2017 12:24:58 +0100
Subject: Rename file without overwriting existing files
In-Reply-To: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <o6n7q5$k8g$1@blaine.gmane.org>

On 01/30/2017 03:49 AM, Steve D'Aprano wrote:
> This code contains a Time Of Check to Time Of Use bug:
>
>     if os.path.exists(destination)
>         raise ValueError('destination already exists')
>     os.rename(oldname, destination)
>
>
> In the microsecond between checking for the existence of the destination and
> actually doing the rename, it is possible that another process may create
> the destination, resulting in data loss.
>
> Apart from keeping my fingers crossed, how should I fix this TOCTOU bug?
>

There is a rather extensive discussion of this problem (with no good 
cross-platform solution if I remember correctly):

https://mail.python.org/pipermail/python-ideas/2011-August/011131.html

which is related to http://bugs.python.org/issue12741

Wolfgang



From hmmeeranrizvi18 at gmail.com  Mon Jan 30 07:11:01 2017
From: hmmeeranrizvi18 at gmail.com (Meeran Rizvi)
Date: Mon, 30 Jan 2017 04:11:01 -0800 (PST)
Subject: Display a label while pressing the button in my GUI
In-Reply-To: <dff79ff1-8136-491b-a903-5c9a91ce5e0c@googlegroups.com>
References: <dff79ff1-8136-491b-a903-5c9a91ce5e0c@googlegroups.com>
Message-ID: <975c607d-ae84-43a4-a0e6-fa18e9f2b5d3@googlegroups.com>

On Monday, January 30, 2017 at 12:02:40 PM UTC+5:30, Meeran Rizvi wrote:
> Hello Guys,
> Here i am creating a GUI which will act as a search engine that will find the results from the browser and save the results as a xls file.
> When i typed something in my search box and click the (GO)button.It should display search in progress.when the file is saved it should display done.
> How to do that?
> My button gets hung for a seconds.We should give any timeout for that?
> 
> Here is my script
> <python>
> from Tkinter import *
> import mechanize
> def clear_search(event):
>     search.delete(0,END)
> obj = Tk()
> Label = Label(obj,text="Top Findings:",font="-weight bold")
> search = Entry(obj,width=100)
> search.insert(0, "Enter the value to search")
> search.bind("<Button-1>", clear_search)
> def fun():
>     new = search.get()
>     url = "http://duckduckgo.com/html"
>     br = mechanize.Browser()
>     br.set_handle_robots(False)
>     br.open(url)
>     br.select_form(name="x")
>     br["q"] = str(new)
>     res = br.submit()
>     content = res.read()
>     with open("result1.xls", "w") as f:
>         f.write(content)
> fun()
> Go = Button(obj,text="GO",width=5,command=fun)
> Label.pack()
> search.pack()
> Go.pack()
> mainloop()
> </python>

Hi Peter,
can u explain about these functions 
def start_search():
    thread = threading.Thread(
        target=fun,
        args=(search.get(),)
    )
    thread.setDaemon(True)
    thread.start()
    root.after(100, check_state)

def check_state():
    while True:
        try:
            message = queue.get_nowait()
        except Queue.Empty:
            break
        state_info["text"] = message
        if message == "done":
            return
    root.after(100, check_state)


From __peter__ at web.de  Mon Jan 30 08:26:16 2017
From: __peter__ at web.de (Peter Otten)
Date: Mon, 30 Jan 2017 14:26:16 +0100
Subject: Display a label while pressing the button in my GUI
References: <dff79ff1-8136-491b-a903-5c9a91ce5e0c@googlegroups.com>
 <975c607d-ae84-43a4-a0e6-fa18e9f2b5d3@googlegroups.com>
Message-ID: <o6netk$tl7$1@blaine.gmane.org>

Meeran Rizvi wrote:

> On Monday, January 30, 2017 at 12:02:40 PM UTC+5:30, Meeran Rizvi wrote:
>> Hello Guys,
>> Here i am creating a GUI which will act as a search engine that will find
>> the results from the browser and save the results as a xls file. When i
>> typed something in my search box and click the (GO)button.It should
>> display search in progress.when the file is saved it should display done.
>> How to do that? My button gets hung for a seconds.We should give any
>> timeout for that?
>> 
>> Here is my script
>> <python>
>> from Tkinter import *
>> import mechanize
>> def clear_search(event):
>>     search.delete(0,END)
>> obj = Tk()
>> Label = Label(obj,text="Top Findings:",font="-weight bold")
>> search = Entry(obj,width=100)
>> search.insert(0, "Enter the value to search")
>> search.bind("<Button-1>", clear_search)
>> def fun():
>>     new = search.get()
>>     url = "http://duckduckgo.com/html"
>>     br = mechanize.Browser()
>>     br.set_handle_robots(False)
>>     br.open(url)
>>     br.select_form(name="x")
>>     br["q"] = str(new)
>>     res = br.submit()
>>     content = res.read()
>>     with open("result1.xls", "w") as f:
>>         f.write(content)
>> fun()
>> Go = Button(obj,text="GO",width=5,command=fun)
>> Label.pack()
>> search.pack()
>> Go.pack()
>> mainloop()
>> </python>
> 
> Hi Peter,
> can u explain about these functions
> def start_search():

This creates a new thread; target and args specify that in that thread
fun will be invoked with the current contents of the search Entry.

>     thread = threading.Thread(
>         target=fun,
>         args=(search.get(),)
>     )
>     thread.setDaemon(True)
>     thread.start()

This tells Tkinter to run the check_state function 100 milliseconds later.

>     root.after(100, check_state)

As the -- aptly named ;) -- start_search() only starts the search without 
having to wait for the result it will only block the GUI for a moment that 
should normally be too short for the user to note.

You can think of the resulting script as two mini-programs that -- at least 
conceptually -- run indepently. If they access each other's data you can get 
an inconsistent state. The Queue class is written with precautions to avoid 
such problems. check_state() and Tkinter run in the main thread and only 
receive data from the thread executing fun() through the queue.

> def check_state():
>     while True:

          Look into the queue if there is a message from fun(). If there is
          return it, otherwise instead of waiting for the next message to
          arrive raise an exception immediately. Remember, if we stay here
          too long the GUI will lag.

>         try:
>             message = queue.get_nowait()
>         except Queue.Empty:

          Case (1) No pending messages, break out of the loop.

>             break

          Case (2) We have a message. Update the text of the state_info
          Label accordingly,

>         state_info["text"] = message

          then check if it's the last message we expect.

>         if message == "done":

              Yes it's the last message; leave check_state() without
              rescheduling it.

>             return

      We got here from the break statement. There are currently no messages, 
      but there may be later, so we ask Tkinter to run check_state again in
      100 milliseconds.

>     root.after(100, check_state)

PS: You can verify that you understood this by answering the question: what 
happens if the user hits the go-button while the second thread is still 
running. Hint: as written the script does not handle this correctly.



From jon+usenet at unequivocal.eu  Mon Jan 30 08:36:13 2017
From: jon+usenet at unequivocal.eu (Jon Ribbens)
Date: Mon, 30 Jan 2017 13:36:13 -0000 (UTC)
Subject: Rename file without overwriting existing files
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
 <20170130043303.GA78047@cskk.homeip.net>
 <mailman.152.1485750834.2473.python-list@python.org>
 <588f127e$0$1586$c3e8da3$5496439d@news.astraweb.com>
 <o6n55h$9of$1@blaine.gmane.org>
 <mailman.165.1485772799.2473.python-list@python.org>
 <lf5efzkn7f2.fsf@ling.helsinki.fi>
Message-ID: <slrno8ugdk.3j6.jon+usenet@sable.unequivocal.eu>

On 2017-01-30, Jussi Piitulainen <jussi.piitulainen at helsinki.fi> wrote:
> It doesn't seem to be documented. I looked at help(os.link) on Python
> 3.4 and the corresponding current library documentation on the web. I
> saw no mention of what happens when dst exists already.
>
> Also, creating a hard link doesn't seem to work between different file
> systems, which may well be relevant to Steve's case. I get:
>
>     OSError: [Errno 18] Invalid cross-device link: [snip]
>
> And that also is not mentioned in the docs.

Nor *should* either of those things be mentioned in the Python docs.

A lot of the functions of the 'os' module do nothing but call the
underlying OS system call with the same name. It would not only be
redundant to copy the OS documentation into the Python documentation,
it would be misleading and wrong, because of course the behaviour may
vary slightly from OS to OS.


From __peter__ at web.de  Mon Jan 30 08:46:39 2017
From: __peter__ at web.de (Peter Otten)
Date: Mon, 30 Jan 2017 14:46:39 +0100
Subject: Display a label while pressing the button in my GUI
References: <dff79ff1-8136-491b-a903-5c9a91ce5e0c@googlegroups.com>
 <975c607d-ae84-43a4-a0e6-fa18e9f2b5d3@googlegroups.com>
 <o6netk$tl7$1@blaine.gmane.org>
Message-ID: <o6ng3q$pr$1@blaine.gmane.org>

Peter Otten wrote:

> PS: You can verify that you understood this by answering the question:
> what happens if the user hits the go-button while the second thread is
> still running. Hint: as written the script does not handle this correctly.

On second thought it's probably not as bad as I thought when I wrote the 
above. I assumed that the messages after the first "done" would remain in 
the queue forever, but there is another independent check_state() invocation 
that should read the rest.
I hope ;)




From __peter__ at web.de  Mon Jan 30 08:51:31 2017
From: __peter__ at web.de (Peter Otten)
Date: Mon, 30 Jan 2017 14:51:31 +0100
Subject: Rename file without overwriting existing files
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
 <20170130043303.GA78047@cskk.homeip.net>
 <mailman.152.1485750834.2473.python-list@python.org>
 <588f127e$0$1586$c3e8da3$5496439d@news.astraweb.com>
 <o6n55h$9of$1@blaine.gmane.org>
 <mailman.165.1485772799.2473.python-list@python.org>
 <lf5efzkn7f2.fsf@ling.helsinki.fi>
 <slrno8ugdk.3j6.jon+usenet@sable.unequivocal.eu>
Message-ID: <o6ngcu$9hi$1@blaine.gmane.org>

Jon Ribbens wrote:

> On 2017-01-30, Jussi Piitulainen <jussi.piitulainen at helsinki.fi> wrote:
>> It doesn't seem to be documented. I looked at help(os.link) on Python
>> 3.4 and the corresponding current library documentation on the web. I
>> saw no mention of what happens when dst exists already.
>>
>> Also, creating a hard link doesn't seem to work between different file
>> systems, which may well be relevant to Steve's case. I get:
>>
>>     OSError: [Errno 18] Invalid cross-device link: [snip]
>>
>> And that also is not mentioned in the docs.
> 
> Nor *should* either of those things be mentioned in the Python docs.
> 
> A lot of the functions of the 'os' module do nothing but call the
> underlying OS system call with the same name. It would not only be
> redundant to copy the OS documentation into the Python documentation,
> it would be misleading and wrong, because of course the behaviour may
> vary slightly from OS to OS.

However, the current Python version of link() is sufficiently different from 
<https://linux.die.net/man/2/link>, say, to warrant its own documentation.



From __peter__ at web.de  Mon Jan 30 08:58:10 2017
From: __peter__ at web.de (Peter Otten)
Date: Mon, 30 Jan 2017 14:58:10 +0100
Subject: Rename file without overwriting existing files
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
 <20170130043303.GA78047@cskk.homeip.net>
 <mailman.152.1485750834.2473.python-list@python.org>
 <588f127e$0$1586$c3e8da3$5496439d@news.astraweb.com>
 <o6n55h$9of$1@blaine.gmane.org>
 <mailman.165.1485772799.2473.python-list@python.org>
 <lf5efzkn7f2.fsf@ling.helsinki.fi>
Message-ID: <o6ngpd$v2i$1@blaine.gmane.org>

Jussi Piitulainen wrote:

> Peter Otten writes:
> 
>> Steve D'Aprano wrote:

>>> The wider context is that I'm taking from 1 to <arbitrarily huge number>
>>> path names to existing files as arguments, and for each path name I
>>> transfer the file name part (but not the directory part) and then rename
>>> the file. For example:
>>> 
>>> foo/bar/baz/spam.txt
>>>
>>> may be renamed to:
>>>
>>> foo/bar/baz/ham.txt
>>> 
>>> but only provided ham.txt doesn't already exist.
>>
>> Google finds
>>
>> http://stackoverflow.com/questions/3222341/how-to-rename-without-race-conditions
>>
>> and from a quick test it appears to work on Linux:
> 
> It doesn't seem to be documented. 

For functions with a C equivalent a look into the man page is usually 
helpful.

> I looked at help(os.link) on Python
> 3.4 and the corresponding current library documentation on the web. I
> saw no mention of what happens when dst exists already.
> 
> Also, creating a hard link doesn't seem to work between different file
> systems, which may well be relevant to Steve's case.

In his example above he operates inside a single directory. Can one 
directory spread across multiple file systems?

> I get:
> 
>     OSError: [Errno 18] Invalid cross-device link: [snip]
> 
> And that also is not mentioned in the docs.




From jon+usenet at unequivocal.eu  Mon Jan 30 09:10:58 2017
From: jon+usenet at unequivocal.eu (Jon Ribbens)
Date: Mon, 30 Jan 2017 14:10:58 -0000 (UTC)
Subject: Rename file without overwriting existing files
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
 <20170130043303.GA78047@cskk.homeip.net>
 <mailman.152.1485750834.2473.python-list@python.org>
 <588f127e$0$1586$c3e8da3$5496439d@news.astraweb.com>
 <o6n55h$9of$1@blaine.gmane.org>
 <mailman.165.1485772799.2473.python-list@python.org>
 <lf5efzkn7f2.fsf@ling.helsinki.fi>
 <slrno8ugdk.3j6.jon+usenet@sable.unequivocal.eu>
 <o6ngcu$9hi$1@blaine.gmane.org>
 <mailman.173.1485784513.2473.python-list@python.org>
Message-ID: <slrno8uiep.3j6.jon+usenet@sable.unequivocal.eu>

On 2017-01-30, Peter Otten <__peter__ at web.de> wrote:
> Jon Ribbens wrote:
>> A lot of the functions of the 'os' module do nothing but call the
>> underlying OS system call with the same name. It would not only be
>> redundant to copy the OS documentation into the Python documentation,
>> it would be misleading and wrong, because of course the behaviour may
>> vary slightly from OS to OS.
>
> However, the current Python version of link() is sufficiently different from 
><https://linux.die.net/man/2/link>, say, to warrant its own documentation.

What are you referring to here? As far as I can see, the current
Python implementation of link() just calls the underlying OS call
directly.


From hmmeeranrizvi18 at gmail.com  Mon Jan 30 09:13:21 2017
From: hmmeeranrizvi18 at gmail.com (Meeran Rizvi)
Date: Mon, 30 Jan 2017 06:13:21 -0800 (PST)
Subject: Display a label while pressing the button in my GUI
In-Reply-To: <dff79ff1-8136-491b-a903-5c9a91ce5e0c@googlegroups.com>
References: <dff79ff1-8136-491b-a903-5c9a91ce5e0c@googlegroups.com>
Message-ID: <05235018-464b-422d-9b38-686c021abf1a@googlegroups.com>

On Monday, January 30, 2017 at 12:02:40 PM UTC+5:30, Meeran Rizvi wrote:
> Hello Guys,
> Here i am creating a GUI which will act as a search engine that will find the results from the browser and save the results as a xls file.
> When i typed something in my search box and click the (GO)button.It should display search in progress.when the file is saved it should display done.
> How to do that?
> My button gets hung for a seconds.We should give any timeout for that?
> 
> Here is my script
> <python>
> from Tkinter import *
> import mechanize
> def clear_search(event):
>     search.delete(0,END)
> obj = Tk()
> Label = Label(obj,text="Top Findings:",font="-weight bold")
> search = Entry(obj,width=100)
> search.insert(0, "Enter the value to search")
> search.bind("<Button-1>", clear_search)
> def fun():
>     new = search.get()
>     url = "http://duckduckgo.com/html"
>     br = mechanize.Browser()
>     br.set_handle_robots(False)
>     br.open(url)
>     br.select_form(name="x")
>     br["q"] = str(new)
>     res = br.submit()
>     content = res.read()
>     with open("result1.xls", "w") as f:
>         f.write(content)
> fun()
> Go = Button(obj,text="GO",width=5,command=fun)
> Label.pack()
> search.pack()
> Go.pack()
> mainloop()
> </python>

Thanks for the explanation Peter


From hmmeeranrizvi18 at gmail.com  Mon Jan 30 09:14:47 2017
From: hmmeeranrizvi18 at gmail.com (Meeran Rizvi)
Date: Mon, 30 Jan 2017 06:14:47 -0800 (PST)
Subject: Display a label while pressing the button in my GUI
In-Reply-To: <dff79ff1-8136-491b-a903-5c9a91ce5e0c@googlegroups.com>
References: <dff79ff1-8136-491b-a903-5c9a91ce5e0c@googlegroups.com>
Message-ID: <35e6a5ba-f128-471b-8a28-ed0bc4ad6c18@googlegroups.com>

On Monday, January 30, 2017 at 12:02:40 PM UTC+5:30, Meeran Rizvi wrote:
> Hello Guys,
> Here i am creating a GUI which will act as a search engine that will find the results from the browser and save the results as a xls file.
> When i typed something in my search box and click the (GO)button.It should display search in progress.when the file is saved it should display done.
> How to do that?
> My button gets hung for a seconds.We should give any timeout for that?
> 
> Here is my script
> <python>
> from Tkinter import *
> import mechanize
> def clear_search(event):
>     search.delete(0,END)
> obj = Tk()
> Label = Label(obj,text="Top Findings:",font="-weight bold")
> search = Entry(obj,width=100)
> search.insert(0, "Enter the value to search")
> search.bind("<Button-1>", clear_search)
> def fun():
>     new = search.get()
>     url = "http://duckduckgo.com/html"
>     br = mechanize.Browser()
>     br.set_handle_robots(False)
>     br.open(url)
>     br.select_form(name="x")
>     br["q"] = str(new)
>     res = br.submit()
>     content = res.read()
>     with open("result1.xls", "w") as f:
>         f.write(content)
> fun()
> Go = Button(obj,text="GO",width=5,command=fun)
> Label.pack()
> search.pack()
> Go.pack()
> mainloop()
> </python>

It is possible to display the output in my GUI itself?


From rosuav at gmail.com  Mon Jan 30 09:18:39 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 31 Jan 2017 01:18:39 +1100
Subject: Rename file without overwriting existing files
In-Reply-To: <o6ngpd$v2i$1@blaine.gmane.org>
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
 <20170130043303.GA78047@cskk.homeip.net>
 <mailman.152.1485750834.2473.python-list@python.org>
 <588f127e$0$1586$c3e8da3$5496439d@news.astraweb.com>
 <o6n55h$9of$1@blaine.gmane.org>
 <mailman.165.1485772799.2473.python-list@python.org>
 <lf5efzkn7f2.fsf@ling.helsinki.fi> <o6ngpd$v2i$1@blaine.gmane.org>
Message-ID: <CAPTjJmpSxe-u0d02nnMNKsu6eWKppQD-8jpwFiESKogJUAwe6g@mail.gmail.com>

On Tue, Jan 31, 2017 at 12:58 AM, Peter Otten <__peter__ at web.de> wrote:
>> I looked at help(os.link) on Python
>> 3.4 and the corresponding current library documentation on the web. I
>> saw no mention of what happens when dst exists already.
>>
>> Also, creating a hard link doesn't seem to work between different file
>> systems, which may well be relevant to Steve's case.
>
> In his example above he operates inside a single directory. Can one
> directory spread across multiple file systems?

Yep. Try unionfs.

... make ourselves some scratch space ...
$ mkdir space modifier
$ dd if=/dev/zero of=space.img bs=4096 count=65536
$ mkfs space.img
$ sudo mount space.img space
$ dd if=/dev/zero of=modifier.img bs=4096 count=1024\
$ mkfs modifier.img
$ sudo mount modifier.img modifier

... put some content into the base directory ...
$ sudo -e space/demo.txt

... and now the magic:
$ unionfs modifier=RW:space=RO joiner/
$ cd joiner

At this point, you're in a directory that is the union of the two
directories. One of them is read-only, the other is read/write. It is
thus possible to view a file that you can't hard-link to a new name,
because the new name would have to be created in the 'modifier' file
system, but the old file exists on the 'space' one.

ChrisA


From __peter__ at web.de  Mon Jan 30 09:38:12 2017
From: __peter__ at web.de (Peter Otten)
Date: Mon, 30 Jan 2017 15:38:12 +0100
Subject: Rename file without overwriting existing files
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
 <20170130043303.GA78047@cskk.homeip.net>
 <mailman.152.1485750834.2473.python-list@python.org>
 <588f127e$0$1586$c3e8da3$5496439d@news.astraweb.com>
 <o6n55h$9of$1@blaine.gmane.org>
 <mailman.165.1485772799.2473.python-list@python.org>
 <lf5efzkn7f2.fsf@ling.helsinki.fi>
 <slrno8ugdk.3j6.jon+usenet@sable.unequivocal.eu>
 <o6ngcu$9hi$1@blaine.gmane.org>
 <mailman.173.1485784513.2473.python-list@python.org>
 <slrno8uiep.3j6.jon+usenet@sable.unequivocal.eu>
Message-ID: <o6nj4f$170$1@blaine.gmane.org>

Jon Ribbens wrote:

> On 2017-01-30, Peter Otten <__peter__ at web.de> wrote:
>> Jon Ribbens wrote:
>>> A lot of the functions of the 'os' module do nothing but call the
>>> underlying OS system call with the same name. It would not only be
>>> redundant to copy the OS documentation into the Python documentation,
>>> it would be misleading and wrong, because of course the behaviour may
>>> vary slightly from OS to OS.
>>
>> However, the current Python version of link() is sufficiently different
>> from
>><https://linux.die.net/man/2/link>, say, to warrant its own documentation.
> 
> What are you referring to here? As far as I can see, the current
> Python implementation of link() just calls the underlying OS call
> directly.

The current signature differs from that of link()

os.link(src, dst, *, src_dir_fd=None, dst_dir_fd=None, follow_symlinks=True)


but it looks like you are right in so far as link() is still called by 
default:

    if ((src_dir_fd != DEFAULT_DIR_FD) ||
        (dst_dir_fd != DEFAULT_DIR_FD) ||
        (!follow_symlinks))
        result = linkat(src_dir_fd, src->narrow,
            dst_dir_fd, dst->narrow,
            follow_symlinks ? AT_SYMLINK_FOLLOW : 0);
    else
#endif /* HAVE_LINKAT */
        result = link(src->narrow, dst->narrow);




From jussi.piitulainen at helsinki.fi  Mon Jan 30 09:40:15 2017
From: jussi.piitulainen at helsinki.fi (Jussi Piitulainen)
Date: Mon, 30 Jan 2017 16:40:15 +0200
Subject: Rename file without overwriting existing files
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
 <20170130043303.GA78047@cskk.homeip.net>
 <mailman.152.1485750834.2473.python-list@python.org>
 <588f127e$0$1586$c3e8da3$5496439d@news.astraweb.com>
 <o6n55h$9of$1@blaine.gmane.org>
 <mailman.165.1485772799.2473.python-list@python.org>
 <lf5efzkn7f2.fsf@ling.helsinki.fi> <o6ngpd$v2i$1@blaine.gmane.org>
 <mailman.174.1485784811.2473.python-list@python.org>
Message-ID: <lf5y3xsligg.fsf@ling.helsinki.fi>

Peter Otten writes:

> Jussi Piitulainen wrote:
>
>> Peter Otten writes:
>> 
>>> Steve D'Aprano wrote:
>
>>>> The wider context is that I'm taking from 1 to <arbitrarily huge number>
>>>> path names to existing files as arguments, and for each path name I
>>>> transfer the file name part (but not the directory part) and then rename
>>>> the file. For example:
>>>> 
>>>> foo/bar/baz/spam.txt
>>>>
>>>> may be renamed to:
>>>>
>>>> foo/bar/baz/ham.txt
>>>> 
>>>> but only provided ham.txt doesn't already exist.
>>>
>>> Google finds
>>>
>>> http://stackoverflow.com/questions/3222341/how-to-rename-without-race-conditions
>>>
>>> and from a quick test it appears to work on Linux:
>> 
>> It doesn't seem to be documented. 
>
> For functions with a C equivalent a look into the man page is usually
> helpful.

Followed by a few test cases to see what Python actually does, at least
in those particular test cases, I suppose. Yes.

But is it a bug in Python if a Python function *doesn't* do what the
relevant man page in the user's operating system says? Or whatever the
user's documentation entry is called. For me, yes, it's a man page.

>> I looked at help(os.link) on Python
>> 3.4 and the corresponding current library documentation on the web. I
>> saw no mention of what happens when dst exists already.
>> 
>> Also, creating a hard link doesn't seem to work between different file
>> systems, which may well be relevant to Steve's case.
>
> In his example above he operates inside a single directory. Can one
> directory spread across multiple file systems?

Hm, you are right, he does say he's working in a single directory.

But *I'm* currently working on processes where results from a batch
system are eventually moved to another directory, and I have no control
over the file systems. So while it was interesting to learn about
os.link, I cannot use os.link here; on the other hand, I can use
shutil.move, and in my present case it will only accidentally overwrite
a file if I've made a programming mistake myself, or if the underlying
platform is not working as advertised, so I'm in a different situation.

[- -]


From __peter__ at web.de  Mon Jan 30 09:49:22 2017
From: __peter__ at web.de (Peter Otten)
Date: Mon, 30 Jan 2017 15:49:22 +0100
Subject: Display a label while pressing the button in my GUI
References: <dff79ff1-8136-491b-a903-5c9a91ce5e0c@googlegroups.com>
 <35e6a5ba-f128-471b-8a28-ed0bc4ad6c18@googlegroups.com>
Message-ID: <o6njpg$rma$1@blaine.gmane.org>

Meeran Rizvi wrote:

> On Monday, January 30, 2017 at 12:02:40 PM UTC+5:30, Meeran Rizvi wrote:
>> Hello Guys,
>> Here i am creating a GUI which will act as a search engine that will find
>> the results from the browser and save the results as a xls file. When i
>> typed something in my search box and click the (GO)button.It should
>> display search in progress.when the file is saved it should display done.
>> How to do that? My button gets hung for a seconds.We should give any
>> timeout for that?
>> 
>> Here is my script
>> <python>
>> from Tkinter import *
>> import mechanize
>> def clear_search(event):
>>     search.delete(0,END)
>> obj = Tk()
>> Label = Label(obj,text="Top Findings:",font="-weight bold")
>> search = Entry(obj,width=100)
>> search.insert(0, "Enter the value to search")
>> search.bind("<Button-1>", clear_search)
>> def fun():
>>     new = search.get()
>>     url = "http://duckduckgo.com/html"
>>     br = mechanize.Browser()
>>     br.set_handle_robots(False)
>>     br.open(url)
>>     br.select_form(name="x")
>>     br["q"] = str(new)
>>     res = br.submit()
>>     content = res.read()
>>     with open("result1.xls", "w") as f:
>>         f.write(content)
>> fun()
>> Go = Button(obj,text="GO",width=5,command=fun)
>> Label.pack()
>> search.pack()
>> Go.pack()
>> mainloop()
>> </python>
> 
> It is possible to display the output in my GUI itself?

Instead of the strings "searching", "writing result", and "done" you could 
put search results into the queue and display them in a Text widget. To 
signal when you're done you can use an out-of-band value, typically None.

See also <http://effbot.org/zone/tkinter-threads.htm>.




From hmmeeranrizvi18 at gmail.com  Mon Jan 30 09:55:56 2017
From: hmmeeranrizvi18 at gmail.com (Meeran Rizvi)
Date: Mon, 30 Jan 2017 06:55:56 -0800 (PST)
Subject: Display a label while pressing the button in my GUI
In-Reply-To: <mailman.177.1485787777.2473.python-list@python.org>
References: <dff79ff1-8136-491b-a903-5c9a91ce5e0c@googlegroups.com>
 <35e6a5ba-f128-471b-8a28-ed0bc4ad6c18@googlegroups.com>
 <o6njpg$rma$1@blaine.gmane.org>
 <mailman.177.1485787777.2473.python-list@python.org>
Message-ID: <b8dac6a6-83bb-4cc4-b246-14d129e4a7dc@googlegroups.com>

On Monday, January 30, 2017 at 8:19:47 PM UTC+5:30, Peter Otten wrote:
> Meeran Rizvi wrote:
> 
> > On Monday, January 30, 2017 at 12:02:40 PM UTC+5:30, Meeran Rizvi wrote:
> >> Hello Guys,
> >> Here i am creating a GUI which will act as a search engine that will find
> >> the results from the browser and save the results as a xls file. When i
> >> typed something in my search box and click the (GO)button.It should
> >> display search in progress.when the file is saved it should display done.
> >> How to do that? My button gets hung for a seconds.We should give any
> >> timeout for that?
> >> 
> >> Here is my script
> >> <python>
> >> from Tkinter import *
> >> import mechanize
> >> def clear_search(event):
> >>     search.delete(0,END)
> >> obj = Tk()
> >> Label = Label(obj,text="Top Findings:",font="-weight bold")
> >> search = Entry(obj,width=100)
> >> search.insert(0, "Enter the value to search")
> >> search.bind("<Button-1>", clear_search)
> >> def fun():
> >>     new = search.get()
> >>     url = "http://duckduckgo.com/html"
> >>     br = mechanize.Browser()
> >>     br.set_handle_robots(False)
> >>     br.open(url)
> >>     br.select_form(name="x")
> >>     br["q"] = str(new)
> >>     res = br.submit()
> >>     content = res.read()
> >>     with open("result1.xls", "w") as f:
> >>         f.write(content)
> >> fun()
> >> Go = Button(obj,text="GO",width=5,command=fun)
> >> Label.pack()
> >> search.pack()
> >> Go.pack()
> >> mainloop()
> >> </python>
> > 
> > It is possible to display the output in my GUI itself?
> 
> Instead of the strings "searching", "writing result", and "done" you could 
> put search results into the queue and display them in a Text widget. To 
> signal when you're done you can use an out-of-band value, typically None.
> 
> See also <http://effbot.org/zone/tkinter-threads.htm>.

I just want to save it as a xls file and also from xls file i need to get the data and display in a text box.
 


From hmmeeranrizvi18 at gmail.com  Mon Jan 30 09:58:54 2017
From: hmmeeranrizvi18 at gmail.com (Meeran Rizvi)
Date: Mon, 30 Jan 2017 06:58:54 -0800 (PST)
Subject: Display a label while pressing the button in my GUI
In-Reply-To: <b8dac6a6-83bb-4cc4-b246-14d129e4a7dc@googlegroups.com>
References: <dff79ff1-8136-491b-a903-5c9a91ce5e0c@googlegroups.com>
 <35e6a5ba-f128-471b-8a28-ed0bc4ad6c18@googlegroups.com>
 <o6njpg$rma$1@blaine.gmane.org>
 <mailman.177.1485787777.2473.python-list@python.org>
 <b8dac6a6-83bb-4cc4-b246-14d129e4a7dc@googlegroups.com>
Message-ID: <80d57db0-ac99-4d24-85be-46d8af502bd4@googlegroups.com>

On Monday, January 30, 2017 at 8:26:07 PM UTC+5:30, Meeran Rizvi wrote:
> On Monday, January 30, 2017 at 8:19:47 PM UTC+5:30, Peter Otten wrote:
> > Meeran Rizvi wrote:
> > 
> > > On Monday, January 30, 2017 at 12:02:40 PM UTC+5:30, Meeran Rizvi wrote:
> > >> Hello Guys,
> > >> Here i am creating a GUI which will act as a search engine that will find
> > >> the results from the browser and save the results as a xls file. When i
> > >> typed something in my search box and click the (GO)button.It should
> > >> display search in progress.when the file is saved it should display done.
> > >> How to do that? My button gets hung for a seconds.We should give any
> > >> timeout for that?
> > >> 
> > >> Here is my script
> > >> <python>
> > >> from Tkinter import *
> > >> import mechanize
> > >> def clear_search(event):
> > >>     search.delete(0,END)
> > >> obj = Tk()
> > >> Label = Label(obj,text="Top Findings:",font="-weight bold")
> > >> search = Entry(obj,width=100)
> > >> search.insert(0, "Enter the value to search")
> > >> search.bind("<Button-1>", clear_search)
> > >> def fun():
> > >>     new = search.get()
> > >>     url = "http://duckduckgo.com/html"
> > >>     br = mechanize.Browser()
> > >>     br.set_handle_robots(False)
> > >>     br.open(url)
> > >>     br.select_form(name="x")
> > >>     br["q"] = str(new)
> > >>     res = br.submit()
> > >>     content = res.read()
> > >>     with open("result1.xls", "w") as f:
> > >>         f.write(content)
> > >> fun()
> > >> Go = Button(obj,text="GO",width=5,command=fun)
> > >> Label.pack()
> > >> search.pack()
> > >> Go.pack()
> > >> mainloop()
> > >> </python>
> > > 
> > > It is possible to display the output in my GUI itself?
> > 
> > Instead of the strings "searching", "writing result", and "done" you could 
> > put search results into the queue and display them in a Text widget. To 
> > signal when you're done you can use an out-of-band value, typically None.
> > 
> > See also <http://effbot.org/zone/tkinter-threads.htm>.
> 
> I just want to save it as a xls file and also from xls file i need to get the data and display in a text box.

Or either i just display the output in my text widget and also save it as an xls file


From tjreedy at udel.edu  Mon Jan 30 10:00:09 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Mon, 30 Jan 2017 10:00:09 -0500
Subject: Rename file without overwriting existing files
In-Reply-To: <o6ngpd$v2i$1@blaine.gmane.org>
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
 <20170130043303.GA78047@cskk.homeip.net>
 <mailman.152.1485750834.2473.python-list@python.org>
 <588f127e$0$1586$c3e8da3$5496439d@news.astraweb.com>
 <o6n55h$9of$1@blaine.gmane.org>
 <mailman.165.1485772799.2473.python-list@python.org>
 <lf5efzkn7f2.fsf@ling.helsinki.fi> <o6ngpd$v2i$1@blaine.gmane.org>
Message-ID: <o6nkdl$kdf$1@blaine.gmane.org>

On 1/30/2017 8:58 AM, Peter Otten wrote:
> Jussi Piitulainen wrote:

>> It doesn't seem to be documented.
>
> For functions with a C equivalent a look into the man page is usually
> helpful.

Man pages do not exist on Windows.  I suspect that there are more 
individual Python programs on Windows than *nix.  I am more sure of this 
as applied to beginners, most of whom have no idea what a 'man' page is 
(sexist docs? ;-).

-- 
Terry Jan Reedy



From jcasale at activenetwerx.com  Mon Jan 30 10:05:27 2017
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Mon, 30 Jan 2017 15:05:27 +0000
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <CAPTjJmo3H5gbaTyiM_+wujqYuD0wgud3FLQ33-chJN_jsDtAYA@mail.gmail.com>
References: <ad38b3d3415f4294b407d345d8313e6a@activenetwerx.com>
 <001801d27a7c$6452b140$27b23dae@sambora>
 <c828d670c8ed4137924cd3aebe387942@activenetwerx.com>
 <CAPTjJmo3H5gbaTyiM_+wujqYuD0wgud3FLQ33-chJN_jsDtAYA@mail.gmail.com>
Message-ID: <e38c0366243f41bd83123cc369dd0660@activenetwerx.com>

> What do you mean by "both platforms"? Python scripts already run on
> three major operating systems (Win/Lin/Mac) and a good number of
> less-popular OSes; a well-written Python script will run in four major
> Pythons (CPython, PyPy, Jython, IronPython) and a number of others;
> and all manner of CPU architectures and so on.

I meant exactly what you did, in hindsight it was less than perfect wording
on my part...

Thanks,
jlc


From __peter__ at web.de  Mon Jan 30 10:14:16 2017
From: __peter__ at web.de (Peter Otten)
Date: Mon, 30 Jan 2017 16:14:16 +0100
Subject: Rename file without overwriting existing files
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
 <20170130043303.GA78047@cskk.homeip.net>
 <mailman.152.1485750834.2473.python-list@python.org>
 <588f127e$0$1586$c3e8da3$5496439d@news.astraweb.com>
 <o6n55h$9of$1@blaine.gmane.org>
 <mailman.165.1485772799.2473.python-list@python.org>
 <lf5efzkn7f2.fsf@ling.helsinki.fi> <o6ngpd$v2i$1@blaine.gmane.org>
 <CAPTjJmpSxe-u0d02nnMNKsu6eWKppQD-8jpwFiESKogJUAwe6g@mail.gmail.com>
Message-ID: <o6nl82$29t$1@blaine.gmane.org>

Chris Angelico wrote:

> On Tue, Jan 31, 2017 at 12:58 AM, Peter Otten <__peter__ at web.de> wrote:
>>> I looked at help(os.link) on Python
>>> 3.4 and the corresponding current library documentation on the web. I
>>> saw no mention of what happens when dst exists already.
>>>
>>> Also, creating a hard link doesn't seem to work between different file
>>> systems, which may well be relevant to Steve's case.
>>
>> In his example above he operates inside a single directory. Can one
>> directory spread across multiple file systems?
> 
> Yep. Try unionfs.
> 
> ... make ourselves some scratch space ...
> $ mkdir space modifier
> $ dd if=/dev/zero of=space.img bs=4096 count=65536
> $ mkfs space.img
> $ sudo mount space.img space
> $ dd if=/dev/zero of=modifier.img bs=4096 count=1024\
> $ mkfs modifier.img
> $ sudo mount modifier.img modifier
> 
> ... put some content into the base directory ...
> $ sudo -e space/demo.txt
> 
> ... and now the magic:
> $ unionfs modifier=RW:space=RO joiner/
> $ cd joiner
> 
> At this point, you're in a directory that is the union of the two
> directories. One of them is read-only, the other is read/write. It is
> thus possible to view a file that you can't hard-link to a new name,
> because the new name would have to be created in the 'modifier' file
> system, but the old file exists on the 'space' one.

Interesting example, thanks!



From __peter__ at web.de  Mon Jan 30 10:25:11 2017
From: __peter__ at web.de (Peter Otten)
Date: Mon, 30 Jan 2017 16:25:11 +0100
Subject: Display a label while pressing the button in my GUI
References: <dff79ff1-8136-491b-a903-5c9a91ce5e0c@googlegroups.com>
 <35e6a5ba-f128-471b-8a28-ed0bc4ad6c18@googlegroups.com>
 <o6njpg$rma$1@blaine.gmane.org>
 <mailman.177.1485787777.2473.python-list@python.org>
 <b8dac6a6-83bb-4cc4-b246-14d129e4a7dc@googlegroups.com>
 <80d57db0-ac99-4d24-85be-46d8af502bd4@googlegroups.com>
Message-ID: <o6nlsk$cj$1@blaine.gmane.org>

Meeran Rizvi wrote:

>  I just want to save it as a xls file and also from xls file i need to get
>  the data and display in a text box.
> 
> Or either i just display the output in my text widget and also save it as
> an xls file

What exactly you want to do is up to you; just try your hands at it and come 
back here when you run into problems.
Keep in mind that whatever you do in the GUI thread you should only spend a 
small amount of time on it at once. 

If the task is big break it into parts, e. g. instead of reading a complete 
web page or file break it into smaller blocks that you insert into the 
widget one after another.

As to the XLS file, I recommend that you first try the conversion from HTML 
to XLS in a small separate script that reads HTML from a file on your 
computer. Once it works is should be easy to integrate a working conversion 
function into a working Search GUI.



From jon+usenet at unequivocal.eu  Mon Jan 30 10:40:05 2017
From: jon+usenet at unequivocal.eu (Jon Ribbens)
Date: Mon, 30 Jan 2017 15:40:05 -0000 (UTC)
Subject: Rename file without overwriting existing files
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
 <20170130043303.GA78047@cskk.homeip.net>
 <mailman.152.1485750834.2473.python-list@python.org>
 <588f127e$0$1586$c3e8da3$5496439d@news.astraweb.com>
 <o6n55h$9of$1@blaine.gmane.org>
 <mailman.165.1485772799.2473.python-list@python.org>
 <lf5efzkn7f2.fsf@ling.helsinki.fi>
 <slrno8ugdk.3j6.jon+usenet@sable.unequivocal.eu>
 <o6ngcu$9hi$1@blaine.gmane.org>
 <mailman.173.1485784513.2473.python-list@python.org>
 <slrno8uiep.3j6.jon+usenet@sable.unequivocal.eu>
 <o6nj4f$170$1@blaine.gmane.org>
 <mailman.176.1485787108.2473.python-list@python.org>
Message-ID: <slrno8unls.3j6.jon+usenet@sable.unequivocal.eu>

On 2017-01-30, Peter Otten <__peter__ at web.de> wrote:
> Jon Ribbens wrote:
>> On 2017-01-30, Peter Otten <__peter__ at web.de> wrote:
>>> However, the current Python version of link() is sufficiently different
>>> from
>>><https://linux.die.net/man/2/link>, say, to warrant its own documentation.
>> 
>> What are you referring to here? As far as I can see, the current
>> Python implementation of link() just calls the underlying OS call
>> directly.
>
> The current signature differs from that of link()
>
> os.link(src, dst, *, src_dir_fd=None, dst_dir_fd=None, follow_symlinks=True)
>
> but it looks like you are right in so far as link() is still called by 
> default:

Yeah, it's been extended to call linkat() if the extra parameters are
provided, but it still calls link() if you call it like link().

So basically it's been extended analogously to how Linux has been,
and the OS manpage is still the right place to look to understand
what it does. (linkat() is documented as part of the same manpage as
link() anyway.)


From grant.b.edwards at gmail.com  Mon Jan 30 10:48:16 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Mon, 30 Jan 2017 15:48:16 +0000 (UTC)
Subject: Rename file without overwriting existing files
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
 <20170130043303.GA78047@cskk.homeip.net>
 <mailman.152.1485750834.2473.python-list@python.org>
 <588f127e$0$1586$c3e8da3$5496439d@news.astraweb.com>
 <o6n55h$9of$1@blaine.gmane.org>
 <mailman.165.1485772799.2473.python-list@python.org>
 <lf5efzkn7f2.fsf@ling.helsinki.fi>
Message-ID: <o6nn80$vuf$1@blaine.gmane.org>

On 2017-01-30, Jussi Piitulainen <jussi.piitulainen at helsinki.fi> wrote:

> It doesn't seem to be documented. I looked at help(os.link) on Python
> 3.4 and the corresponding current library documentation on the web. I
> saw no mention of what happens when dst exists already.

The functions in the os module are thin-as-possible wrappers around
the OS's libc functions.  The authors of the os module don't really
have any way of knowing the details of what your os/libc combination
is going to do.

If you're calling os.foo(), you're sort of expected to know what foo()
does on your OS.

> Also, creating a hard link doesn't seem to work between different file
> systems, which may well be relevant to Steve's case. I get:
>
>     OSError: [Errno 18] Invalid cross-device link: [snip]
>
> And that also is not mentioned in the docs.

Again, that's a detail that depends on your particular
OS/libc/filesystem implementation.  It's not determined by nor
knowable by the authors of the os module.

-- 
Grant Edwards               grant.b.edwards        Yow! I'm ANN LANDERS!!
                                  at               I can SHOPLIFT!!
                              gmail.com            



From saxri89 at gmail.com  Mon Jan 30 10:55:39 2017
From: saxri89 at gmail.com (Xristos Xristoou)
Date: Mon, 30 Jan 2017 07:55:39 -0800 (PST)
Subject: count points where is within the polygons using shapely and fiona
In-Reply-To: <e1798fb3-056b-44c3-b74d-c96a7345edd8@googlegroups.com>
References: <e1798fb3-056b-44c3-b74d-c96a7345edd8@googlegroups.com>
Message-ID: <b45f50ba-06be-40a2-ac81-062b6d3dee47@googlegroups.com>

tell your proposal to count


From grant.b.edwards at gmail.com  Mon Jan 30 10:56:01 2017
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Mon, 30 Jan 2017 15:56:01 +0000 (UTC)
Subject: Rename file without overwriting existing files
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
 <20170130043303.GA78047@cskk.homeip.net>
 <mailman.152.1485750834.2473.python-list@python.org>
 <588f127e$0$1586$c3e8da3$5496439d@news.astraweb.com>
 <o6n55h$9of$1@blaine.gmane.org>
 <mailman.165.1485772799.2473.python-list@python.org>
 <lf5efzkn7f2.fsf@ling.helsinki.fi> <o6ngpd$v2i$1@blaine.gmane.org>
 <o6nkdl$kdf$1@blaine.gmane.org>
Message-ID: <o6nnmh$vuf$2@blaine.gmane.org>

On 2017-01-30, Terry Reedy <tjreedy at udel.edu> wrote:
> On 1/30/2017 8:58 AM, Peter Otten wrote:
>> Jussi Piitulainen wrote:
>
>>> It doesn't seem to be documented.
>>
>> For functions with a C equivalent a look into the man page is usually
>> helpful.
>
> Man pages do not exist on Windows.  I suspect that there are more 
> individual Python programs on Windows than *nix.  I am more sure of this 
> as applied to beginners, most of whom have no idea what a 'man' page is 
> (sexist docs? ;-).

IMO, beginners shouldn't be using the os module.  This is implied by
the first parapgraph of the doc:

     If you just want to read or write a file see open(), if you want
     to manipulate paths, see the os.path module, and if you want to
     read all the lines in all the files on the command line see the
     fileinput module. For creating temporary files and directories
     see the tempfile module, and for high-level file and directory
     handling see the shutil module.

When you're using the OS module, you're just writing C code in Python.
[Which, BTW, is a _very_ useful thing to be able to do, but it's
probably not what beginners are trying to do.]

I always found the first sentence to be a bit funny:

     This module provides a portable way of using operating system
     dependent functionality.

I understand whay they're tying to say, but I always found it amusing
to say you're going to provide a portable way to do something
non-portable.

-- 
Grant Edwards               grant.b.edwards        Yow! Somewhere in DOWNTOWN
                                  at               BURBANK a prostitute is
                              gmail.com            OVERCOOKING a LAMB CHOP!!



From ian.g.kelly at gmail.com  Mon Jan 30 11:05:37 2017
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Mon, 30 Jan 2017 09:05:37 -0700
Subject: Overriding True and False ?
In-Reply-To: <CAPTjJmrRQ0EEjZ4tvdx0YeNRjZzttovFaXbniekO_txwkvTA7g@mail.gmail.com>
References: <3F8981B9-4D4B-41B0-A864-24388A35F5FD@furrypants.com>
 <CAPTjJmrRQ0EEjZ4tvdx0YeNRjZzttovFaXbniekO_txwkvTA7g@mail.gmail.com>
Message-ID: <CALwzid=NJmGdGTqCkNJZ_oWQ6ayihzBX5BrFbSLMY4SditwfyQ@mail.gmail.com>

On Jan 30, 2017 2:00 AM, "Chris Angelico" <rosuav at gmail.com> wrote:

(Interestingly, Ellipsis is not
included in that.)


Perhaps because it's rather unusual for a program to depend upon the value
of Ellipsis.


From marko at pacujo.net  Mon Jan 30 11:11:50 2017
From: marko at pacujo.net (Marko Rauhamaa)
Date: Mon, 30 Jan 2017 18:11:50 +0200
Subject: Rename file without overwriting existing files
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
 <20170130043303.GA78047@cskk.homeip.net>
 <mailman.152.1485750834.2473.python-list@python.org>
 <588f127e$0$1586$c3e8da3$5496439d@news.astraweb.com>
 <o6n55h$9of$1@blaine.gmane.org>
 <mailman.165.1485772799.2473.python-list@python.org>
 <lf5efzkn7f2.fsf@ling.helsinki.fi> <o6ngpd$v2i$1@blaine.gmane.org>
 <o6nkdl$kdf$1@blaine.gmane.org> <o6nnmh$vuf$2@blaine.gmane.org>
 <mailman.183.1485791784.2473.python-list@python.org>
Message-ID: <87sho08r3t.fsf@elektro.pacujo.net>

Grant Edwards <grant.b.edwards at gmail.com>:

> IMO, beginners shouldn't be using the os module.

Hard to know. Depends on what the beginner wants to accomplish.

> I always found the first sentence to be a bit funny:
>
>      This module provides a portable way of using operating system
>      dependent functionality.
>
> I understand whay they're tying to say, but I always found it amusing
> to say you're going to provide a portable way to do something
> non-portable.

One of the best things in Python is that it has exposed the operating
system to the application programmer. I don't think a programming
language should abstract the operating system away.


Marko


From ian.g.kelly at gmail.com  Mon Jan 30 11:12:50 2017
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Mon, 30 Jan 2017 09:12:50 -0700
Subject: Overriding True and False ?
In-Reply-To: <3F8981B9-4D4B-41B0-A864-24388A35F5FD@furrypants.com>
References: <3F8981B9-4D4B-41B0-A864-24388A35F5FD@furrypants.com>
Message-ID: <CALwzidm0SAjW0XK7q7OC3-HOEVp2kWt=d+9GTY_pXMuDpKjHyg@mail.gmail.com>

On Jan 30, 2017 1:32 AM, "Irv Kalb" <Irv at furrypants.com> wrote:

I teach intro to programming using Python.  In my first assignment,
students are asked to assign variables of different types and print out the
values.

One student (who really did not understand Booleans) turned in the
following for his/her interpretation of Booleans (Python 2.7):

True = 'shadow'
False = 'light'
print "If the sun is behind a cloud, there is", True
print "If it is a clear day, there is", False

And it printed:

If the sun is behind a cloud, there is shadow
If it is a clear day, there is light


It seems very odd that Python allows you to override the values of True and
False.  In the code, True and False were clearly recognized as keywords as
they were colored purple.  But there was no error message.


Plenty of people have remarked that this is fixed in Python 3, but nobody
that I see has explained yet the reason for this behavior in the first
place. True and False are not keywords in Python 2 for backward
compatibility. Many versions ago, Python did not define True and False at
all. It was common in that era to lead scripts with:

    False = 0
    True = 1

To define useful boolean constants. When the built-in constants were added,
the developers did not want to break programs that followed this pattern.

This is also the reason why bool is a subclass of int -- so that False == 0
and True == 1 remain true for programs that depend on this.


From cl at isbd.net  Mon Jan 30 12:58:30 2017
From: cl at isbd.net (Chris Green)
Date: Mon, 30 Jan 2017 17:58:30 +0000
Subject: What library/package to use for parsing XML?
Message-ID: <6fb4md-kns.ln1@esprimo.zbmc.eu>

I want to parse some XML data, it's the address book data from the
linux program osmo.  The file I want to parse is like this:-

    <?xml version="1.0" encoding="utf-8"?>
    <osmo_contacts>
      <contacts_groups/>
      <contacts_records>
        <record>
          <group>None</group>
          <first_name>Peter and Denise</first_name>
          <last_name>Smith</last_name>
          <birthday_date>0</birthday_date>
          <name_day_date>0</name_day_date>
          <home_address>Some address</home_address>
          <home_postcode>AAA BBB</home_postcode>
          <home_state>Oxfordshire</home_state>
        </record>
      </contacts_records>
    </osmo_contacts>


I basically want to be able to extract the data and output in other
formats - e.g. write to a Sqlite3 database and/or CSV.

So what do I need to import (and probably install first) to do this?


-- 
Chris Green
?


From juan0christian at gmail.com  Mon Jan 30 13:44:15 2017
From: juan0christian at gmail.com (Juan C.)
Date: Mon, 30 Jan 2017 16:44:15 -0200
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <CAAp0bGup1DOJBU0+52eqsb-XqOi6Pv1zGJ2bWvgUMtPuZ1v3YA@mail.gmail.com>
References: <CAAp0bGup1DOJBU0+52eqsb-XqOi6Pv1zGJ2bWvgUMtPuZ1v3YA@mail.gmail.com>
Message-ID: <CAAp0bGvohNUsAo5v5A_FLFBKbXkyD+gUbqXtAEeGRhrHNG2xwA@mail.gmail.com>

On Sun, Jan 29, 2017 at 1:06 AM, Juan C. <juan0christian at gmail.com> wrote:
>
> As you guys might know, .NET Core is up and running, promising a "cross-platform, unified, fast, lightweight, modern and open source experience" (source: .NET Core official site). What do you guys think about it? Do you think it will be able to compete with and overcome Python in the opensource medium?

Oh, I forgot to say, I was indeed talking about .NET Core in general,
the framework, but I also had C#/ASP .NET Core in mind. The real
comparison here would be C#/ASP .NET Core vs Python/Django,Flask. I
personally had to work with C# a few times, it's a great language, but
my main problem was that it was Windows only and most of my personal
programs run on Linux. Yes, we have Mono, but it really didn't feel
"right" to me, it seemed like a workaround, I wanted something really
"native".

Python still has my heart, but .NET Core tempts me. One great thing of
coding in C# would be no GIL.


From jcasale at activenetwerx.com  Mon Jan 30 15:33:42 2017
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Mon, 30 Jan 2017 20:33:42 +0000
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <CAAp0bGvohNUsAo5v5A_FLFBKbXkyD+gUbqXtAEeGRhrHNG2xwA@mail.gmail.com>
References: <CAAp0bGup1DOJBU0+52eqsb-XqOi6Pv1zGJ2bWvgUMtPuZ1v3YA@mail.gmail.com>
 <CAAp0bGvohNUsAo5v5A_FLFBKbXkyD+gUbqXtAEeGRhrHNG2xwA@mail.gmail.com>
Message-ID: <5eed732b8ec64871a33e7b8fea23c002@activenetwerx.com>

> Python still has my heart, but .NET Core tempts me. One great thing of
> coding in C# would be no GIL.

Seriously, check out the benchmarks at https://github.com/aspnet/benchmarks.

I think aside from the obvious, you'll find the Razor engine and the overall library
to be a pleasure to work with. The framework is truly a representation of what
a high quality, brilliantly engineered piece of software looks like.


From irmen.NOSPAM at xs4all.nl  Mon Jan 30 16:12:18 2017
From: irmen.NOSPAM at xs4all.nl (Irmen de Jong)
Date: Mon, 30 Jan 2017 22:12:18 +0100
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <mailman.187.1485808727.2473.python-list@python.org>
References: <CAAp0bGup1DOJBU0+52eqsb-XqOi6Pv1zGJ2bWvgUMtPuZ1v3YA@mail.gmail.com>
 <CAAp0bGvohNUsAo5v5A_FLFBKbXkyD+gUbqXtAEeGRhrHNG2xwA@mail.gmail.com>
 <5eed732b8ec64871a33e7b8fea23c002@activenetwerx.com>
 <mailman.187.1485808727.2473.python-list@python.org>
Message-ID: <588fac31$0$786$e4fe514c@news.xs4all.nl>

On 30-1-2017 21:33, Joseph L. Casale wrote:
>> Python still has my heart, but .NET Core tempts me. One great thing of
>> coding in C# would be no GIL.
> 
> Seriously, check out the benchmarks at https://github.com/aspnet/benchmarks.

Results vary quite a bit there.
For instance take the json serialization benchmark:
https://www.techempower.com/benchmarks/#section=data-r13&hw=ph&test=json
There's 6 python frameworks performing better than aspcore in this chart...


Irmen



From irmen.NOSPAM at xs4all.nl  Mon Jan 30 16:20:08 2017
From: irmen.NOSPAM at xs4all.nl (Irmen de Jong)
Date: Mon, 30 Jan 2017 22:20:08 +0100
Subject: What library/package to use for parsing XML?
In-Reply-To: <6fb4md-kns.ln1@esprimo.zbmc.eu>
References: <6fb4md-kns.ln1@esprimo.zbmc.eu>
Message-ID: <588fae07$0$786$e4fe514c@news.xs4all.nl>

On 30-1-2017 18:58, Chris Green wrote:
> I want to parse some XML data, it's the address book data from the
> linux program osmo.  The file I want to parse is like this:-
> 

[snip]

> 
> I basically want to be able to extract the data and output in other
> formats - e.g. write to a Sqlite3 database and/or CSV.
> 
> So what do I need to import (and probably install first) to do this?

No need to install anything. Python has batteries included.

Parse your XML with xml.etree.ElementTree
    [https://docs.python.org/3/library/xml.etree.elementtree.html]
Read/write CSV with csv
    [https://docs.python.org/3/library/csv.html]
Put stuff in sqlite3 database and query it using sqlite3
    [https://docs.python.org/3/library/sqlite3.html]


-irmen




From juan0christian at gmail.com  Mon Jan 30 17:14:54 2017
From: juan0christian at gmail.com (Juan C.)
Date: Mon, 30 Jan 2017 20:14:54 -0200
Subject: What library/package to use for parsing XML?
In-Reply-To: <6fb4md-kns.ln1@esprimo.zbmc.eu>
References: <6fb4md-kns.ln1@esprimo.zbmc.eu>
Message-ID: <CAAp0bGuGx_5s3MePyoZZ3bzpU8UxqjBZ7WybAgGUt=OVAjYsVA@mail.gmail.com>

On Mon, Jan 30, 2017 at 3:58 PM, Chris Green <cl at isbd.net> wrote:
> I want to parse some XML data, it's the address book data from the
> linux program osmo.  The file I want to parse is like this:-

Just like Irmen said, use the default xml.etree.ElementTree, it's
amazing and very simple to use.


From rgaddi at highlandtechnology.invalid  Mon Jan 30 18:05:16 2017
From: rgaddi at highlandtechnology.invalid (Rob Gaddi)
Date: Mon, 30 Jan 2017 15:05:16 -0800
Subject: What library/package to use for parsing XML?
In-Reply-To: <mailman.188.1485814542.2473.python-list@python.org>
References: <6fb4md-kns.ln1@esprimo.zbmc.eu>
 <CAAp0bGuGx_5s3MePyoZZ3bzpU8UxqjBZ7WybAgGUt=OVAjYsVA@mail.gmail.com>
 <mailman.188.1485814542.2473.python-list@python.org>
Message-ID: <o6ogo5$9cj$1@dont-email.me>

On 01/30/2017 02:14 PM, Juan C. wrote:
> On Mon, Jan 30, 2017 at 3:58 PM, Chris Green <cl at isbd.net> wrote:
>> I want to parse some XML data, it's the address book data from the
>> linux program osmo.  The file I want to parse is like this:-
>
> Just like Irmen said, use the default xml.etree.ElementTree, it's
> amazing and very simple to use.
>

And if you get halfway into your project and find ElementTree was 
insufficient, you can switch to lxml without changing practically 
anything you've already written.

-- 
Rob Gaddi, Highland Technology -- www.highlandtechnology.com
Email address domain is currently out of order.  See above to fix.


From jf_byrnes at comcast.net  Mon Jan 30 18:16:24 2017
From: jf_byrnes at comcast.net (Jim)
Date: Mon, 30 Jan 2017 17:16:24 -0600
Subject: How to write libreoffice python macros in venv?
Message-ID: <o6ohg2$jnb$1@blaine.gmane.org>

I have all the necessary libreoffice modules installed in my Mint 18.1 
system to allow me to write libreoffice calc macros in python.

I now have venv installed. If I try to import uno for a calc macro in it 
I get an error that there is no uno module.

How can I get my venv to find uno and the other necessary modules so I 
can write calc macros in it?

Thanks,  Jim




From steve+python at pearwood.info  Mon Jan 30 19:02:06 2017
From: steve+python at pearwood.info (Steve D'Aprano)
Date: Tue, 31 Jan 2017 11:02:06 +1100
Subject: Overriding True and False ?
References: <3F8981B9-4D4B-41B0-A864-24388A35F5FD@furrypants.com>
 <CALwzidm0SAjW0XK7q7OC3-HOEVp2kWt=d+9GTY_pXMuDpKjHyg@mail.gmail.com>
 <mailman.185.1485792773.2473.python-list@python.org>
Message-ID: <588fd400$0$1583$c3e8da3$5496439d@news.astraweb.com>

On Tue, 31 Jan 2017 03:12 am, Ian Kelly wrote:

> On Jan 30, 2017 1:32 AM, "Irv Kalb" <Irv at furrypants.com> wrote:
> 
> I teach intro to programming using Python.  In my first assignment,
> students are asked to assign variables of different types and print out
> the values.
[...]

Hey Ian,

Your news reader or mail client has stopped quoting the text you are
quoting, so it appears as if you have written it.

See:

https://mail.python.org/pipermail/python-list/2017-January/719015.html



-- 
Steve
?Cheer up,? they said, ?things could be worse.? So I cheered up, and sure
enough, things got worse.



From ben+python at benfinney.id.au  Mon Jan 30 19:17:56 2017
From: ben+python at benfinney.id.au (Ben Finney)
Date: Tue, 31 Jan 2017 11:17:56 +1100
Subject: Rename file without overwriting existing files
References: <588ea9c8$0$1605$c3e8da3$5496439d@news.astraweb.com>
 <20170130043303.GA78047@cskk.homeip.net>
 <mailman.152.1485750834.2473.python-list@python.org>
 <588f127e$0$1586$c3e8da3$5496439d@news.astraweb.com>
 <o6n55h$9of$1@blaine.gmane.org>
Message-ID: <8537g0t74b.fsf@benfinney.id.au>

Peter Otten <__peter__ at web.de> writes:

> http://stackoverflow.com/questions/3222341/how-to-rename-without-race-conditions
>
> and from a quick test it appears to work on Linux:

By ?works on Linux?, I assume you mean ?works on filesystems that use
inodes and hard links?. That is not true for all filesystems, even on
Linux.

-- 
 \      ?[Entrenched media corporations will] maintain the status quo, |
  `\       or die trying. Either is better than actually WORKING for a |
_o__)                  living.? ?ringsnake.livejournal.com, 2007-11-12 |
Ben Finney



From torriem at gmail.com  Mon Jan 30 19:35:05 2017
From: torriem at gmail.com (Michael Torrie)
Date: Mon, 30 Jan 2017 17:35:05 -0700
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <CAAp0bGvohNUsAo5v5A_FLFBKbXkyD+gUbqXtAEeGRhrHNG2xwA@mail.gmail.com>
References: <CAAp0bGup1DOJBU0+52eqsb-XqOi6Pv1zGJ2bWvgUMtPuZ1v3YA@mail.gmail.com>
 <CAAp0bGvohNUsAo5v5A_FLFBKbXkyD+gUbqXtAEeGRhrHNG2xwA@mail.gmail.com>
Message-ID: <6ade49f7-e0fa-90e0-7b47-ad5e14c391fe@gmail.com>

On 01/30/2017 11:44 AM, Juan C. wrote:
> On Sun, Jan 29, 2017 at 1:06 AM, Juan C. <juan0christian at gmail.com> wrote:
>>
>> As you guys might know, .NET Core is up and running, promising a "cross-platform, unified, fast, lightweight, modern and open source experience" (source: .NET Core official site). What do you guys think about it? Do you think it will be able to compete with and overcome Python in the opensource medium?
> 
> Oh, I forgot to say, I was indeed talking about .NET Core in general,
> the framework, but I also had C#/ASP .NET Core in mind. The real
> comparison here would be C#/ASP .NET Core vs Python/Django,Flask. I
> personally had to work with C# a few times, it's a great language, but
> my main problem was that it was Windows only and most of my personal
> programs run on Linux. Yes, we have Mono, but it really didn't feel
> "right" to me, it seemed like a workaround, I wanted something really
> "native".

C# under Mono is as native as C# on the DotNet runtime on Windows or
DotNet core on Linux.  However now that DotNet Core is open source and
supported on Linux, Mono is likely to fade away since all of the Xamarin
developers work for MS now.

> Python still has my heart, but .NET Core tempts me. One great thing of
> coding in C# would be no GIL.

C# hardly seems any better than Java to me as far as a language goes.
Being forced into working with classes even when they are not
appropriate is jarring.  Because everything is forced into a class, one
often ends up with very long classes in C#, spanning more than one file!
 Makes the code much harder to follow from a human point of view. After
working in C# I very much appreciate Python's explicit self requirement
for accessing local instance variables.




From gerald.britton at gmail.com  Mon Jan 30 20:06:41 2017
From: gerald.britton at gmail.com (Gerald Britton)
Date: Mon, 30 Jan 2017 20:06:41 -0500
Subject: What are your opinions on .NET Core vs Python?
Message-ID: <CAPxRSnZLsy4RT7JMQ13+-UMVQcSO3XDXGfW=VAvdnfN7NV6dsg@mail.gmail.com>

On Sun, Jan 29, 2017 at 1:06 AM, Juan C. <juan0christian at gmail.com
<https://mail.python.org/mailman/listinfo/python-list>> wrote:
>
> >
> >* As you guys might know, .NET Core is up and running, promising a "cross-platform, unified, fast, lightweight, modern and open source experience" (source: .NET Core official site). What do you guys think about it? Do you think it will be able to compete with and overcome Python in the opensource medium?
> *

Oh, I forgot to say, I was indeed talking about .NET Core in general,
> the framework, but I also had C#/ASP .NET Core in mind. The real
> comparison here would be C#/ASP .NET Core vs Python/Django,Flask. I
> personally had to work with C# a few times, it's a great language, but
> my main problem was that it was Windows only and most of my personal
> programs run on Linux. Yes, we have Mono, but it really didn't feel
> "right" to me, it seemed like a workaround, I wanted something really
> "native".

Python still has my heart, but .NET Core tempts me. One great thing of
> coding in C# would be no GIL.

For what it's worth, IronPython, which is implemented in .NET, has no GIL
and doesn't need it since ir runs on the CLR.  That means that, for some
things, IronPython can be more performant.

No word yet if the IronPython project intends to port to .NET core or
enable to run it on OS's other than Windows.

Also, it's worth noting that the PythonNet project has a branch working on
.NET core support


-- 
Gerald Britton, MCSE-DP, MVP
LinkedIn Profile: http://ca.linkedin.com/in/geraldbritton


From jcasale at activenetwerx.com  Mon Jan 30 20:18:14 2017
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Tue, 31 Jan 2017 01:18:14 +0000
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <6ade49f7-e0fa-90e0-7b47-ad5e14c391fe@gmail.com>
References: <CAAp0bGup1DOJBU0+52eqsb-XqOi6Pv1zGJ2bWvgUMtPuZ1v3YA@mail.gmail.com>
 <CAAp0bGvohNUsAo5v5A_FLFBKbXkyD+gUbqXtAEeGRhrHNG2xwA@mail.gmail.com>
 <6ade49f7-e0fa-90e0-7b47-ad5e14c391fe@gmail.com>
Message-ID: <21c7475509634730811331fe2804cc0f@activenetwerx.com>

> C# hardly seems any better than Java to me as far as a language goes.

Which sounds pretty good to me, they are both high performance, mature
and rich languages.

> Being forced into working with classes even when they are not
> appropriate is jarring.

And 100% irrelevant, it doesn't prevent you from doing anything you
otherwise could without.

> Because everything is forced into a class, one
> often ends up with very long classes in C#, spanning more than one file!

Sorry, sounds like you need to learn SOLID, none of my classes
have ever taken this form.

>  Makes the code much harder to follow from a human point of view. After
> working in C# I very much appreciate Python's explicit self requirement
> for accessing local instance variables.

So, prefix them with "this." and they will look the same? 


From nathan.ernst at gmail.com  Mon Jan 30 20:52:06 2017
From: nathan.ernst at gmail.com (Nathan Ernst)
Date: Mon, 30 Jan 2017 19:52:06 -0600
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <21c7475509634730811331fe2804cc0f@activenetwerx.com>
References: <CAAp0bGup1DOJBU0+52eqsb-XqOi6Pv1zGJ2bWvgUMtPuZ1v3YA@mail.gmail.com>
 <CAAp0bGvohNUsAo5v5A_FLFBKbXkyD+gUbqXtAEeGRhrHNG2xwA@mail.gmail.com>
 <6ade49f7-e0fa-90e0-7b47-ad5e14c391fe@gmail.com>
 <21c7475509634730811331fe2804cc0f@activenetwerx.com>
Message-ID: <CAPjBxg87VFkDG5kKZ=1wKA6oBMUkP0Oja9PEzg8inQ78pWOnqg@mail.gmail.com>

I mostly agree with this

On Mon, Jan 30, 2017 at 7:18 PM, Joseph L. Casale <jcasale at activenetwerx.com
> wrote:

> > C# hardly seems any better than Java to me as far as a language goes.
>
> Which sounds pretty good to me, they are both high performance, mature
> and rich languages.
>
> > Being forced into working with classes even when they are not
> > appropriate is jarring.
>
> And 100% irrelevant, it doesn't prevent you from doing anything you
> otherwise could without.
>
> > Because everything is forced into a class, one
> > often ends up with very long classes in C#, spanning more than one file!
>
> Sorry, sounds like you need to learn SOLID, none of my classes
> have ever taken this form.
>
There is no reason you cannot introduce a static class with pure static
members (i.e. the Math class in System). A static class effectively becomes
another namespace in C++ parlance. I'll admit the syntax is a bit odd, and
enforces you, at a minimum to use the outer name a as a qualifier, but it's
effectively the same effect.

>
> >  Makes the code much harder to follow from a human point of view. After
> > working in C# I very much appreciate Python's explicit self requirement
> > for accessing local instance variables.
>
> So, prefix them with "this." and they will look the same?
> --
> https://mail.python.org/mailman/listinfo/python-list
>
self vs this, and you might start a language holy war. Of course "self" is
the preferred to refer to an instance, just by python convention. Whether I
agree with or not, I've seen "this" used to refer to instances where it is
ambiguous in Python parlance between a "self" instance or a class instance
- those instances are a bit weird, but there are rare occasions you do want
to override class variables where this makes sense (they should be rare -
because it's generally very hard to follow).


From torriem at gmail.com  Mon Jan 30 20:57:18 2017
From: torriem at gmail.com (Michael Torrie)
Date: Mon, 30 Jan 2017 18:57:18 -0700
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <21c7475509634730811331fe2804cc0f@activenetwerx.com>
References: <CAAp0bGup1DOJBU0+52eqsb-XqOi6Pv1zGJ2bWvgUMtPuZ1v3YA@mail.gmail.com>
 <CAAp0bGvohNUsAo5v5A_FLFBKbXkyD+gUbqXtAEeGRhrHNG2xwA@mail.gmail.com>
 <6ade49f7-e0fa-90e0-7b47-ad5e14c391fe@gmail.com>
 <21c7475509634730811331fe2804cc0f@activenetwerx.com>
Message-ID: <e63c7998-5936-4efb-8cb5-ec4f78b60d3b@gmail.com>

On 01/30/2017 06:18 PM, Joseph L. Casale wrote:
> Which sounds pretty good to me, they are both high performance, mature
> and rich languages.

Sure it's a matter of personal preference and need.  I happen to find
the expressivity and flexibility of Python (warts and all) to be rather
liberating compared to Java.  I find Java rather stifling particularly
because of the forced OOP structure.

Not really sure what you mean by "rich language."  Java has a rich
runtime library and a rich ecosystem of utility libraries to draw on.
So does C#.  And so does Python.

> Sorry, sounds like you need to learn SOLID, none of my classes
> have ever taken this form.

Never said they were my classes, or even my programs.  What is this
"SOLID" thing?

In any case, partial classes seems like a misfeature of C# to me but
apparently they are used when making Windows Forms GUI-based apps.
Apparently VS autogenerates the class that backs the form, and then the
developer creates a partial class that extends that to flesh out the
logic and handle the events.  I'm surprised you haven't encountered this.

>>  Makes the code much harder to follow from a human point of view. After
>> working in C# I very much appreciate Python's explicit self requirement
>> for accessing local instance variables.
> 
> So, prefix them with "this." and they will look the same? 

Probably.  But C# developers never do that (nor is it normal to do that
in C++ either).  Not sure what your point is there. I was merely saying
that I now appreciate the logic of the Python explicit self.



From rosuav at gmail.com  Mon Jan 30 21:02:12 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 31 Jan 2017 13:02:12 +1100
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <e63c7998-5936-4efb-8cb5-ec4f78b60d3b@gmail.com>
References: <CAAp0bGup1DOJBU0+52eqsb-XqOi6Pv1zGJ2bWvgUMtPuZ1v3YA@mail.gmail.com>
 <CAAp0bGvohNUsAo5v5A_FLFBKbXkyD+gUbqXtAEeGRhrHNG2xwA@mail.gmail.com>
 <6ade49f7-e0fa-90e0-7b47-ad5e14c391fe@gmail.com>
 <21c7475509634730811331fe2804cc0f@activenetwerx.com>
 <e63c7998-5936-4efb-8cb5-ec4f78b60d3b@gmail.com>
Message-ID: <CAPTjJmoBM+-11w8EAH7drboBF-DHQFrfHNVYOcfo1JSP=j7DrQ@mail.gmail.com>

On Tue, Jan 31, 2017 at 12:57 PM, Michael Torrie <torriem at gmail.com> wrote:
>> Sorry, sounds like you need to learn SOLID, none of my classes
>> have ever taken this form.
>
> Never said they were my classes, or even my programs.  What is this
> "SOLID" thing?

https://en.wikipedia.org/wiki/SOLID_(object-oriented_design)

Five well-respected principles that every class designer should be
aware of. You won't necessarily follow them all slavishly, but know
what the rules are and why you're breaking them.

ChrisA


From torriem at gmail.com  Mon Jan 30 21:04:23 2017
From: torriem at gmail.com (Michael Torrie)
Date: Mon, 30 Jan 2017 19:04:23 -0700
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <CAPjBxg87VFkDG5kKZ=1wKA6oBMUkP0Oja9PEzg8inQ78pWOnqg@mail.gmail.com>
References: <CAAp0bGup1DOJBU0+52eqsb-XqOi6Pv1zGJ2bWvgUMtPuZ1v3YA@mail.gmail.com>
 <CAAp0bGvohNUsAo5v5A_FLFBKbXkyD+gUbqXtAEeGRhrHNG2xwA@mail.gmail.com>
 <6ade49f7-e0fa-90e0-7b47-ad5e14c391fe@gmail.com>
 <21c7475509634730811331fe2804cc0f@activenetwerx.com>
 <CAPjBxg87VFkDG5kKZ=1wKA6oBMUkP0Oja9PEzg8inQ78pWOnqg@mail.gmail.com>
Message-ID: <ca639a3c-85ce-da96-4478-20d6f836ee13@gmail.com>

On 01/30/2017 06:52 PM, Nathan Ernst wrote:
> self vs this, and you might start a language holy war.

Actually no, you misread his point. He was speaking of C#, not Python.
In C#, the only word you can use is "this."  He was saying that you can
use the explicit self paradigm in C#. Simply prefix each member variable
with "this."




From ian.g.kelly at gmail.com  Mon Jan 30 22:27:41 2017
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Mon, 30 Jan 2017 20:27:41 -0700
Subject: Overriding True and False ?
In-Reply-To: <588fd400$0$1583$c3e8da3$5496439d@news.astraweb.com>
References: <3F8981B9-4D4B-41B0-A864-24388A35F5FD@furrypants.com>
 <CALwzidm0SAjW0XK7q7OC3-HOEVp2kWt=d+9GTY_pXMuDpKjHyg@mail.gmail.com>
 <mailman.185.1485792773.2473.python-list@python.org>
 <588fd400$0$1583$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CALwzidm2E7U8CViVg2JDffzhtOFmGoOaoFWmbquU4u+d9NbtQA@mail.gmail.com>

On Jan 30, 2017 6:07 PM, "Steve D'Aprano" <steve+python at pearwood.info>
wrote:
> Hey Ian,
>
> Your news reader or mail client has stopped quoting the text you are
> quoting, so it appears as if you have written it.
>
> See:
>
> https://mail.python.org/pipermail/python-list/2017-January/719015.html

Well, nuts. It looks fine in my client (the Gmail Android app) so I guess
this must be an issue of HTML versus text content. Unfortunately the mobile
client doesn't have any option for text-only that I can find, so my options
appear to be to laboriously replace the quoting as I've done here, or just
stop using the mobile client.


From ben+python at benfinney.id.au  Mon Jan 30 23:57:04 2017
From: ben+python at benfinney.id.au (Ben Finney)
Date: Tue, 31 Jan 2017 15:57:04 +1100
Subject: Overriding True and False ?
References: <3F8981B9-4D4B-41B0-A864-24388A35F5FD@furrypants.com>
 <CALwzidm0SAjW0XK7q7OC3-HOEVp2kWt=d+9GTY_pXMuDpKjHyg@mail.gmail.com>
 <mailman.185.1485792773.2473.python-list@python.org>
 <588fd400$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CALwzidm2E7U8CViVg2JDffzhtOFmGoOaoFWmbquU4u+d9NbtQA@mail.gmail.com>
Message-ID: <85poj3su73.fsf@benfinney.id.au>

Ian Kelly <ian.g.kelly at gmail.com> writes:

> Well, nuts. It looks fine in my client (the Gmail Android app) so I
> guess this must be an issue of HTML versus text content. Unfortunately
> the mobile client doesn't have any option for text-only that I can
> find, so my options appear to be to laboriously replace the quoting as
> I've done here, or just stop using the mobile client.

For composing discussion posts, yes, I recommend people stop using
mobile clients. It can wait until you're at a real keyboard and a decent
authoring environment.

-- 
 \      ?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 greg.ewing at canterbury.ac.nz  Tue Jan 31 00:26:45 2017
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Tue, 31 Jan 2017 18:26:45 +1300
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <mailman.194.1485827529.2473.python-list@python.org>
References: <CAAp0bGup1DOJBU0+52eqsb-XqOi6Pv1zGJ2bWvgUMtPuZ1v3YA@mail.gmail.com>
 <CAAp0bGvohNUsAo5v5A_FLFBKbXkyD+gUbqXtAEeGRhrHNG2xwA@mail.gmail.com>
 <6ade49f7-e0fa-90e0-7b47-ad5e14c391fe@gmail.com>
 <21c7475509634730811331fe2804cc0f@activenetwerx.com>
 <CAPjBxg87VFkDG5kKZ=1wKA6oBMUkP0Oja9PEzg8inQ78pWOnqg@mail.gmail.com>
 <mailman.194.1485827529.2473.python-list@python.org>
Message-ID: <efalgnFu896U1@mid.individual.net>

Nathan Ernst wrote:
> There is no reason you cannot introduce a static class with pure static
> members (i.e. the Math class in System). A static class effectively becomes
> another namespace in C++ parlance. I'll admit the syntax is a bit odd, and
> enforces you, at a minimum to use the outer name a as a qualifier,

That's the thing I find most frustrating about both C# and Java,
the lack of anything like Python's "from ... import ...". You get
a choice of either effectively doing "import *" on the contents
of a whole class and polluting your namespace, or Fully.Qualifying.
Every.Little.Thing.

-- 
Greg


From greg.ewing at canterbury.ac.nz  Tue Jan 31 00:31:24 2017
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Tue, 31 Jan 2017 18:31:24 +1300
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <mailman.197.1485828267.2473.python-list@python.org>
References: <CAAp0bGup1DOJBU0+52eqsb-XqOi6Pv1zGJ2bWvgUMtPuZ1v3YA@mail.gmail.com>
 <CAAp0bGvohNUsAo5v5A_FLFBKbXkyD+gUbqXtAEeGRhrHNG2xwA@mail.gmail.com>
 <6ade49f7-e0fa-90e0-7b47-ad5e14c391fe@gmail.com>
 <21c7475509634730811331fe2804cc0f@activenetwerx.com>
 <CAPjBxg87VFkDG5kKZ=1wKA6oBMUkP0Oja9PEzg8inQ78pWOnqg@mail.gmail.com>
 <ca639a3c-85ce-da96-4478-20d6f836ee13@gmail.com>
 <mailman.197.1485828267.2473.python-list@python.org>
Message-ID: <efalpeFu9pmU1@mid.individual.net>

Michael Torrie wrote:
> He was saying that you can
> use the explicit self paradigm in C#. Simply prefix each member variable
> with "this."

One can do that in one's own code, but it doesn't help
you to read the code of someone else who hasn't done
that. Since it's not part of the C# culture, the vast
majority of other C# code you encounter won't be using
it.

-- 
Greg


From auriocus at gmx.de  Tue Jan 31 02:21:01 2017
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Tue, 31 Jan 2017 08:21:01 +0100
Subject: Overriding True and False ?
In-Reply-To: <mailman.198.1485833271.2473.python-list@python.org>
References: <3F8981B9-4D4B-41B0-A864-24388A35F5FD@furrypants.com>
 <CALwzidm0SAjW0XK7q7OC3-HOEVp2kWt=d+9GTY_pXMuDpKjHyg@mail.gmail.com>
 <mailman.185.1485792773.2473.python-list@python.org>
 <588fd400$0$1583$c3e8da3$5496439d@news.astraweb.com>
 <CALwzidm2E7U8CViVg2JDffzhtOFmGoOaoFWmbquU4u+d9NbtQA@mail.gmail.com>
 <mailman.198.1485833271.2473.python-list@python.org>
Message-ID: <o6pdpm$9f5$1@dont-email.me>

Am 31.01.17 um 04:27 schrieb Ian Kelly:
> On Jan 30, 2017 6:07 PM, "Steve D'Aprano" <steve+python at pearwood.info>
> wrote:
>> Hey Ian,
>>
>> Your news reader or mail client has stopped quoting the text you are
>> quoting, so it appears as if you have written it.
>>
>> See:
>>
>> https://mail.python.org/pipermail/python-list/2017-January/719015.html
>
> Well, nuts. It looks fine in my client (the Gmail Android app) so I guess
> this must be an issue of HTML versus text content. Unfortunately the mobile
> client doesn't have any option for text-only that I can find, so my options
> appear to be to laboriously replace the quoting as I've done here, or just
> stop using the mobile client.

This one looks fine, FYI.

	Christian


From bob.martin at excite.com  Tue Jan 31 02:30:49 2017
From: bob.martin at excite.com (Bob Martin)
Date: Tue, 31 Jan 2017 07:30:49 GMT
Subject: What are your opinions on .NET Core vs Python?
References: <CAAp0bGup1DOJBU0+52eqsb-XqOi6Pv1zGJ2bWvgUMtPuZ1v3YA@mail.gmail.com>
 <mailman.193.1485825500.2473.python-list@python.org>
Message-ID: <efasp9FjntU1@mid.individual.net>

in 770457 20170131 011814 "Joseph L. Casale" <jcasale at activenetwerx.com> wrote:
>> C# hardly seems any better than Java to me as far as a language goes.
>
>Which sounds pretty good to me, they are both high performance, mature
>and rich languages.
>
>> Being forced into working with classes even when they are not
>> appropriate is jarring.
>
>And 100% irrelevant, it doesn't prevent you from doing anything you
>otherwise could without.
>
>> Because everything is forced into a class, one
>> often ends up with very long classes in C#, spanning more than one file!
>
>Sorry, sounds like you need to learn SOLID, none of my classes
>have ever taken this form.
>
>>  Makes the code much harder to follow from a human point of view. After
>> working in C# I very much appreciate Python's explicit self requirement
>> for accessing local instance variables.
>
>So, prefix them with "this." and they will look the same?

Please include the identity of people you are quoting.


From cl at isbd.net  Tue Jan 31 03:52:22 2017
From: cl at isbd.net (Chris Green)
Date: Tue, 31 Jan 2017 08:52:22 +0000
Subject: What library/package to use for parsing XML?
References: <6fb4md-kns.ln1@esprimo.zbmc.eu>
 <588fae07$0$786$e4fe514c@news.xs4all.nl>
Message-ID: <6rv5md-nba.ln1@esprimo.zbmc.eu>

Irmen de Jong <irmen.NOSPAM at xs4all.nl> wrote:
> On 30-1-2017 18:58, Chris Green wrote:
> > I want to parse some XML data, it's the address book data from the
> > linux program osmo.  The file I want to parse is like this:-
> > 
> 
> [snip]
> 
> > 
> > I basically want to be able to extract the data and output in other
> > formats - e.g. write to a Sqlite3 database and/or CSV.
> > 
> > So what do I need to import (and probably install first) to do this?
> 
> No need to install anything. Python has batteries included.
> 
> Parse your XML with xml.etree.ElementTree
>     [https://docs.python.org/3/library/xml.etree.elementtree.html]
> Read/write CSV with csv
>     [https://docs.python.org/3/library/csv.html]
> Put stuff in sqlite3 database and query it using sqlite3
>     [https://docs.python.org/3/library/sqlite3.html]
> 

Thanks, it was the ElementTree bit I didn't know.  Searching for
'Python XML' produces so many hits it's difficult to see what's
necessary/best.


-- 
Chris Green
?


From paulwolf333 at gmail.com  Tue Jan 31 05:33:31 2017
From: paulwolf333 at gmail.com (Paul Wolf)
Date: Tue, 31 Jan 2017 02:33:31 -0800 (PST)
Subject: command line micro wiki written in Python
Message-ID: <b0d91c15-62a2-4a76-9b46-c38d53d4e08d@googlegroups.com>

I've created a command line utility for managing text files. It's written in Python: 

https://github.com/paul-wolf/yewdoc-client

It makes heavy use of the fantastic Click module by Armin Ronacher: http://click.pocoo.org/5/

This can be thought of in different ways: 

* A micro-wiki

* A note-taking application

* A file manager

The key aspects are 

* Entirely command-line driven

* Text documents only with a slight preference for Markdown

* Make it easy to operate on documents without having to remember where they are or the exact names

* Editor agnostic (vim, emacs, Sublime, Atom, etc.)

Here's how to create a document: 

    yd edit "shopping list"

After editing, saving, closing, you can find again: 

    ?  yd ls -l shop
       15981278      md           61   2017-01-20 12:15:43   shopping list

While some people might gasp at the idea of a command line wiki, I find using the command line with a text editor like emacs the best workflow. I also like not having to worry about where a file of this kind is located. You can also use it to track configuration files: 

    yd take ~/.emacs --symlink

Now, I can edit this. Because it's a link to the actual file - having used the `--symlink` option, the configuration file will be updated: 

    ?  yd ls -l emacs
          1c608cd7      md          113   2016-12-16 10:53:24   emacs
       ln 183a5b80     txt         5608   2017-01-15 12:59:39   /Users/paul/.emacs

Using the cloud sync options lets me get my current config file wherever I am, completely up-to-date. For a more wiki-like experience, I can load all the documents with a common tag so:

    yd browse wolf

This converts all the documents tagged with 'wolf' and loads them in a browser with a simple navigation sidebar.

Convert a Markdown document called "Python3" to .odt: 

    ? yd convert Python3 odt
    python3.odt

There is an optional cloud syncronisation feature that connects to a specific endpoint, https://doc.yew.io: 

    ? yd sync

This requires registration at https://doc.yew.io, which can also be done via command line. But that is entirely optional.

I'd be interested in feedback if there is any interest in using this kind of utility. I'll expose a python API so bulk operations can be done easily on the command line or via scripts.


From daiyueweng at gmail.com  Tue Jan 31 06:28:45 2017
From: daiyueweng at gmail.com (Daiyue Weng)
Date: Tue, 31 Jan 2017 11:28:45 +0000
Subject: update a list element using an element in another list
Message-ID: <CAF_EDkt57MQXGYzNQ84sdFdR2WeEArwYbVP2nK7RCZ3V4p1Z_w@mail.gmail.com>

Hi, I am trying to update a list of dictionaries using another list of
dictionaries correspondingly. In that, for example,

#  the list of dicts that need to be updated
dicts_1 = [{'dict_1': '1'}, {'dict_2': '2'}, {'dict_3': '3'}]

# dict used to update dicts_1
update_dicts = [{'dict_1': '1_1'}, {'dict_2': '1_2'}, {'dict_3': '1_3'}]

so that after updating,

dicts_1 = [{'dict_1': '1_1'}, {'dict_2': '1_2'}, {'dict_3': '1_3'}]

what's the best way to the updates?

This is actually coming from when I tried to create a list of entities
(dictionaries), then updating the entities using another list dictionaries
using google.cloud.datastore.

entities = [Entity(self.client.key(kind, entity_id)) for entity_id in
entity_ids]

# update entities using update_dicts
for j in range(len(entities)):
for i in range(len(update_dicts)):
if j == i:
entities[j].update(update_dicts[i])

I am wondering is there a brief way to do this.

cheers


From rhodri at kynesim.co.uk  Tue Jan 31 06:49:20 2017
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Tue, 31 Jan 2017 11:49:20 +0000
Subject: update a list element using an element in another list
In-Reply-To: <CAF_EDkt57MQXGYzNQ84sdFdR2WeEArwYbVP2nK7RCZ3V4p1Z_w@mail.gmail.com>
References: <CAF_EDkt57MQXGYzNQ84sdFdR2WeEArwYbVP2nK7RCZ3V4p1Z_w@mail.gmail.com>
Message-ID: <5f0872b9-41a2-14b3-ef7a-cd37d0877c26@kynesim.co.uk>

On 31/01/17 11:28, Daiyue Weng wrote:
> Hi, I am trying to update a list of dictionaries using another list of
> dictionaries correspondingly. In that, for example,
>
> #  the list of dicts that need to be updated
> dicts_1 = [{'dict_1': '1'}, {'dict_2': '2'}, {'dict_3': '3'}]
>
> # dict used to update dicts_1
> update_dicts = [{'dict_1': '1_1'}, {'dict_2': '1_2'}, {'dict_3': '1_3'}]
>
> so that after updating,
>
> dicts_1 = [{'dict_1': '1_1'}, {'dict_2': '1_2'}, {'dict_3': '1_3'}]
>
> what's the best way to the updates?
>
> This is actually coming from when I tried to create a list of entities
> (dictionaries), then updating the entities using another list dictionaries
> using google.cloud.datastore.
>
> entities = [Entity(self.client.key(kind, entity_id)) for entity_id in
> entity_ids]
>
> # update entities using update_dicts
> for j in range(len(entities)):
> for i in range(len(update_dicts)):
> if j == i:
> entities[j].update(update_dicts[i])
>
> I am wondering is there a brief way to do this.

This all relies on the lists being in the same order and the same 
length, which is probably an unwise assumption, but it's what your code 
does:

for entity, update_dict in zip(entities, update_dicts):
     entity.update(update_dict)

range(len(something)) is usually a warning sign (code smell, if you 
prefer) that you aren't thinking in Python.  If you really need the list 
index for some nefarious purpose, enumerate(something) is probably still 
a better bet.

-- 
Rhodri James *-* Kynesim Ltd


From jussi.piitulainen at helsinki.fi  Tue Jan 31 06:53:13 2017
From: jussi.piitulainen at helsinki.fi (Jussi Piitulainen)
Date: Tue, 31 Jan 2017 13:53:13 +0200
Subject: update a list element using an element in another list
References: <CAF_EDkt57MQXGYzNQ84sdFdR2WeEArwYbVP2nK7RCZ3V4p1Z_w@mail.gmail.com>
 <mailman.201.1485862128.2473.python-list@python.org>
Message-ID: <lf5mve7zbrq.fsf@ling.helsinki.fi>

Daiyue Weng writes:

> Hi, I am trying to update a list of dictionaries using another list of
> dictionaries correspondingly. In that, for example,
>
> #  the list of dicts that need to be updated
> dicts_1 = [{'dict_1': '1'}, {'dict_2': '2'}, {'dict_3': '3'}]
>
> # dict used to update dicts_1
> update_dicts = [{'dict_1': '1_1'}, {'dict_2': '1_2'}, {'dict_3': '1_3'}]
>
> so that after updating,
>
> dicts_1 = [{'dict_1': '1_1'}, {'dict_2': '1_2'}, {'dict_3': '1_3'}]
>
> what's the best way to the updates?
>
> This is actually coming from when I tried to create a list of entities
> (dictionaries), then updating the entities using another list
> dictionaries using google.cloud.datastore.
>
> entities = [Entity(self.client.key(kind, entity_id)) for entity_id in
> entity_ids]
>
> # update entities using update_dicts
> for j in range(len(entities)):
>     for i in range(len(update_dicts)):
>         if j == i:
>            entities[j].update(update_dicts[i])

[I restored the indentation.]

> I am wondering is there a brief way to do this.

A straightforward algorithmic improvement:

for j in range(len(entities)):
    entities[j].update(update_dicts[j])

The real thing:

for e, u in zip(entities, update_dicts):
    e.update(u)

A thing between those:

for j, e in enumerate(entities):
    e.update(update_dicts[j])

(By symmetry, you could enumerate update_dicts instead.)

It pays to learn zip and enumerate.


From ethan at stoneleaf.us  Tue Jan 31 11:15:58 2017
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 31 Jan 2017 08:15:58 -0800
Subject: command line micro wiki written in Python
In-Reply-To: <b0d91c15-62a2-4a76-9b46-c38d53d4e08d@googlegroups.com>
References: <b0d91c15-62a2-4a76-9b46-c38d53d4e08d@googlegroups.com>
Message-ID: <5890B83E.602@stoneleaf.us>

On 01/31/2017 02:33 AM, Paul Wolf wrote:

> I've created a command line utility for managing text files. It's written in Python...

That sounds really cool!

--
~Ethan~


From torriem at gmail.com  Tue Jan 31 11:18:21 2017
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 31 Jan 2017 09:18:21 -0700
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <efalpeFu9pmU1@mid.individual.net>
References: <CAAp0bGup1DOJBU0+52eqsb-XqOi6Pv1zGJ2bWvgUMtPuZ1v3YA@mail.gmail.com>
 <CAAp0bGvohNUsAo5v5A_FLFBKbXkyD+gUbqXtAEeGRhrHNG2xwA@mail.gmail.com>
 <6ade49f7-e0fa-90e0-7b47-ad5e14c391fe@gmail.com>
 <21c7475509634730811331fe2804cc0f@activenetwerx.com>
 <CAPjBxg87VFkDG5kKZ=1wKA6oBMUkP0Oja9PEzg8inQ78pWOnqg@mail.gmail.com>
 <ca639a3c-85ce-da96-4478-20d6f836ee13@gmail.com>
 <mailman.197.1485828267.2473.python-list@python.org>
 <efalpeFu9pmU1@mid.individual.net>
Message-ID: <37e5755b-3dcb-b0cf-2435-a39e02a0b5de@gmail.com>

On 01/30/2017 10:31 PM, Gregory Ewing wrote:
> Michael Torrie wrote:
>> He was saying that you can
>> use the explicit self paradigm in C#. Simply prefix each member variable
>> with "this."
> 
> One can do that in one's own code, but it doesn't help
> you to read the code of someone else who hasn't done
> that. Since it's not part of the C# culture, the vast
> majority of other C# code you encounter won't be using
> it.

Agreed, and that's what I said in response to his suggestion about doing
that.



From fabiofz at gmail.com  Tue Jan 31 12:17:42 2017
From: fabiofz at gmail.com (Fabio Zadrozny)
Date: Tue, 31 Jan 2017 15:17:42 -0200
Subject: PyDev 5.5.0 Released
Message-ID: <CANXBEFpiT3Zv2ZBPWny7i2h_dXQtq4MUQgWCf99MtBKPOqkjpA@mail.gmail.com>

PyDev 5.5.0 Release Highlights
-------------------------------

* **Important** PyDev now requires Java 8 and Eclipse 4.6 (Neon) onwards.

    * PyDev 5.2.0 is the last release supporting Eclipse 4.5 (Mars).

* If you enjoy PyDev, you can help in keeping it supported through its
Patreon crowdfunding: https://www.patreon.com/fabioz.

* **Refactoring**

    * Fixed refactoring error when dealing with imports which have a
continuation char inside the module name part. **#PyDev-712**

    * When extracting a method, decorators are properly considered for the
new method position. **#PyDev-321**

* **Code completion**

    * When accessing enums, 'value' and 'name' are properly found.
**#PyDev-591**

    * Code completion improved on method chaining. **#PyDev-636** and
**#PyDev-583**

    * It's now possible to choose whether when a code-completion which adds
a local import should add the import to the beginning of the function or
the line above where it was requested.

        * It may be configured in the preferences (Preferences > PyDev >
Editor > Code Completion > Put local imports on top of method?).

        * Default was changed to add it to the top of the method.

* **New actions**

    * **Ctrl+Shift+Alt+O** can be used to open the last hyperlink in the
console that's currently open (it's now possible to jump directly to the
error in some exception). **#PyDev-755**

    * **Ctrl+2,sw** switches the target and value in assign statements (may
not work properly if more than one '=' is found in the line).

* **Debugger**

    * Fixed error when hovering over variable when debugging. **#PyDev-580**

* **Others**

    * Fixed issue in grammar parsing on nested async calls. **#PyDev-753**

    * Fixed issue grouping imports when an import has a continuation char
inside the module part. **#PyDev 712**


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, TextMate bundles and a number of other languages such as
Django Templates, Jinja2, 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/



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://www.pyvmmonitor.com/


From ian.g.kelly at gmail.com  Tue Jan 31 12:45:42 2017
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Tue, 31 Jan 2017 10:45:42 -0700
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <CALwzid=J1DSx1dhxz+cskSECx2LYiBcf0N_7+PZCUdw2pndYAQ@mail.gmail.com>
References: <CAAp0bGup1DOJBU0+52eqsb-XqOi6Pv1zGJ2bWvgUMtPuZ1v3YA@mail.gmail.com>
 <CAAp0bGvohNUsAo5v5A_FLFBKbXkyD+gUbqXtAEeGRhrHNG2xwA@mail.gmail.com>
 <6ade49f7-e0fa-90e0-7b47-ad5e14c391fe@gmail.com>
 <21c7475509634730811331fe2804cc0f@activenetwerx.com>
 <CAPjBxg87VFkDG5kKZ=1wKA6oBMUkP0Oja9PEzg8inQ78pWOnqg@mail.gmail.com>
 <mailman.194.1485827529.2473.python-list@python.org>
 <efalgnFu896U1@mid.individual.net>
 <CALwzid=J1DSx1dhxz+cskSECx2LYiBcf0N_7+PZCUdw2pndYAQ@mail.gmail.com>
Message-ID: <CALwzid=FEf5z+CNpP81U84SPmz_gZ-j_OFe773tKsGDFxsLfMA@mail.gmail.com>

On Jan 30, 2017 11:32 PM, "Gregory Ewing" <greg.ewing at canterbury.ac.nz>
wrote:
> That's the thing I find most frustrating about both C# and Java,
> the lack of anything like Python's "from ... import ...". You get
> a choice of either effectively doing "import *" on the contents
> of a whole class and polluting your namespace, or Fully.Qualifying.
> Every.Little.Thing.

I'm not sure about C#, but this is certainly not true in Java. Importing a
class adds exactly one name to your namespace, just as in Python, which is
the unqualified name of the class. Java also has "static import" which lets
you individually import specific static methods or fields from a class.


From ian.g.kelly at gmail.com  Tue Jan 31 12:55:34 2017
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Tue, 31 Jan 2017 10:55:34 -0700
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <e63c7998-5936-4efb-8cb5-ec4f78b60d3b@gmail.com>
References: <CAAp0bGup1DOJBU0+52eqsb-XqOi6Pv1zGJ2bWvgUMtPuZ1v3YA@mail.gmail.com>
 <CAAp0bGvohNUsAo5v5A_FLFBKbXkyD+gUbqXtAEeGRhrHNG2xwA@mail.gmail.com>
 <6ade49f7-e0fa-90e0-7b47-ad5e14c391fe@gmail.com>
 <21c7475509634730811331fe2804cc0f@activenetwerx.com>
 <e63c7998-5936-4efb-8cb5-ec4f78b60d3b@gmail.com>
Message-ID: <CALwzidmDAT-kUSKoNxK4JaqBa-Py6M9fAfX9AVvMjUgrtJoOBQ@mail.gmail.com>

On Jan 30, 2017 8:00 PM, "Michael Torrie" <torriem at gmail.com> wrote:
> In any case, partial classes seems like a misfeature of C# to me but
> apparently they are used when making Windows Forms GUI-based apps.
> Apparently VS autogenerates the class that backs the form, and then the
> developer creates a partial class that extends that to flesh out the
> logic and handle the events.

I'm not sure that partial classes were ever really meant as anything other
than a useful feature for code-generating IDEs. But if you think that's
weird, read up on C# extension methods, which are how users of your classes
can add their own methods to them. True, this is also possible in Python
but requires monkey-patching which is rightfully frowned upon.


From george.trojan at noaa.gov  Tue Jan 31 14:18:58 2017
From: george.trojan at noaa.gov (George Trojan - NOAA Federal)
Date: Tue, 31 Jan 2017 19:18:58 +0000
Subject: Python3.6 tkinter bug?
Message-ID: <CABie7_pjhkKRUmKWhpr-LTwSXqzGjZ8-YbbghYLRXmJ2YKTTmA@mail.gmail.com>

The following program behaves differently under Python 3.6:

'''
checkbutton test
'''

import tkinter

class GUI(tkinter.Tk):
    def __init__(self):
        tkinter.Tk.__init__(self)
        frame = tkinter.Frame(self)
        for tag in ('A', 'B'):
            w = tkinter.Checkbutton(frame, text=tag)
            w.pack(side='top', padx=10, pady=10)
            print(w)
        frame.pack(side='top')
        frame = tkinter.Frame(self)
        for tag in ('C', 'D'):
            w = tkinter.Checkbutton(frame, text=tag)
            w.pack(side='top', padx=10, pady=10)
            print(w)
        frame.pack(side='top')

gui = GUI()
gui.mainloop()

Selection of button 'A' also selects button 'C'. Same goes for 'B' and 'D'.
I noticed that widget names have changed, which likely leads to the cause:

> /usr/local/Python-3.5.1/bin/python3 foo.py
.140182648425776.140182647743208
.140182648425776.140182647841848
.140182648424152.140182648282080
.140182648424152.140182648282136

> /usr/local/Python-3.6.0/bin/python3 foo.py
.!frame.!checkbutton
.!frame.!checkbutton2
.!frame2.!checkbutton
.!frame2.!checkbutton2

Is this a known issue?

George


From larry.martell at gmail.com  Tue Jan 31 15:26:05 2017
From: larry.martell at gmail.com (Larry Martell)
Date: Tue, 31 Jan 2017 15:26:05 -0500
Subject: sorting a list of dicts by a computed field
Message-ID: <CACwCsY5WucJ8AeP9MH_n+z9qqnRc7ZpfQ_tLQaieM5iCugOD2w@mail.gmail.com>

I have a list of dicts and one item of the dict is a date in m/d/Y
format. I want to sort by that. I tried this:

sorted(data['trends'], key=lambda k:
datetime.strptime(k['date_time'],'%m/%d/%Y'))

But that fails with:

Exception Type: AttributeError at /report/CDSEM/WaferAlignment/ajax/waChart.json
Exception Value: 'module' object has no attribute 'strptime'

How can I do this sort?


From rosuav at gmail.com  Tue Jan 31 15:30:52 2017
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 1 Feb 2017 07:30:52 +1100
Subject: sorting a list of dicts by a computed field
In-Reply-To: <CACwCsY5WucJ8AeP9MH_n+z9qqnRc7ZpfQ_tLQaieM5iCugOD2w@mail.gmail.com>
References: <CACwCsY5WucJ8AeP9MH_n+z9qqnRc7ZpfQ_tLQaieM5iCugOD2w@mail.gmail.com>
Message-ID: <CAPTjJmpaANExgin=i7bseBXhQpjFa_cZKiTNiC8gMCq78pXv3A@mail.gmail.com>

On Wed, Feb 1, 2017 at 7:26 AM, Larry Martell <larry.martell at gmail.com> wrote:
> I have a list of dicts and one item of the dict is a date in m/d/Y
> format. I want to sort by that. I tried this:
>
> sorted(data['trends'], key=lambda k:
> datetime.strptime(k['date_time'],'%m/%d/%Y'))
>
> But that fails with:
>
> Exception Type: AttributeError at /report/CDSEM/WaferAlignment/ajax/waChart.json
> Exception Value: 'module' object has no attribute 'strptime'
>
> How can I do this sort?

I think your problem here may be with how you're trying to parse that
datetime. There are two common ways to get access to a thing called
"datetime":

# Option 1:
import datetime
# Option 2:
from datetime import datetime

The first one gives you a module; the second gives you just one class
out of that module (one that happens to have the same name as the
module itself). My guess is that you're using the first form, but you
picked up some example code from somewhere that assumes the second.

Try using "datetime.datetime.strptime" in your key function, and see
if that helps.

ChrisA


From kevin.p.dwyer at gmail.com  Tue Jan 31 15:33:08 2017
From: kevin.p.dwyer at gmail.com (Kev Dwyer)
Date: Tue, 31 Jan 2017 20:33:08 +0000
Subject: sorting a list of dicts by a computed field
References: <CACwCsY5WucJ8AeP9MH_n+z9qqnRc7ZpfQ_tLQaieM5iCugOD2w@mail.gmail.com>
Message-ID: <o6qs9v$8jd$1@blaine.gmane.org>

Larry Martell wrote:

> I have a list of dicts and one item of the dict is a date in m/d/Y
> format. I want to sort by that. I tried this:
> 
> sorted(data['trends'], key=lambda k:
> datetime.strptime(k['date_time'],'%m/%d/%Y'))
> 
> But that fails with:
> 
> Exception Type: AttributeError at
> /report/CDSEM/WaferAlignment/ajax/waChart.json Exception Value: 'module'
> object has no attribute 'strptime'
> 
> How can I do this sort?

datetime.datetime.strptime?

>>> import datetime
>>> datetime.strptime
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: module 'datetime' has no attribute 'strptime'
>>> datetime.datetime.strptime
<built-in method strptime of type object at 0x7f716c2f5d20>




From python at mrabarnett.plus.com  Tue Jan 31 15:34:14 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Tue, 31 Jan 2017 20:34:14 +0000
Subject: sorting a list of dicts by a computed field
In-Reply-To: <CACwCsY5WucJ8AeP9MH_n+z9qqnRc7ZpfQ_tLQaieM5iCugOD2w@mail.gmail.com>
References: <CACwCsY5WucJ8AeP9MH_n+z9qqnRc7ZpfQ_tLQaieM5iCugOD2w@mail.gmail.com>
Message-ID: <b3d1a5e7-435e-b033-564f-66d58778da3d@mrabarnett.plus.com>

On 2017-01-31 20:26, Larry Martell wrote:
> I have a list of dicts and one item of the dict is a date in m/d/Y
> format. I want to sort by that. I tried this:
>
> sorted(data['trends'], key=lambda k:
> datetime.strptime(k['date_time'],'%m/%d/%Y'))
>
> But that fails with:
>
> Exception Type: AttributeError at /report/CDSEM/WaferAlignment/ajax/waChart.json
> Exception Value: 'module' object has no attribute 'strptime'
>
> How can I do this sort?
>
The module 'datetime' contains a class called 'datetime'. Judging by 
your exception, 'datetime' is the module.

Try "datetime.datetime.strptime" instead.



From torriem at gmail.com  Tue Jan 31 15:36:40 2017
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 31 Jan 2017 13:36:40 -0700
Subject: sorting a list of dicts by a computed field
In-Reply-To: <CACwCsY5WucJ8AeP9MH_n+z9qqnRc7ZpfQ_tLQaieM5iCugOD2w@mail.gmail.com>
References: <CACwCsY5WucJ8AeP9MH_n+z9qqnRc7ZpfQ_tLQaieM5iCugOD2w@mail.gmail.com>
Message-ID: <7a563f6f-10c2-20e6-4379-26f219007d81@gmail.com>

On 01/31/2017 01:26 PM, Larry Martell wrote:
> I have a list of dicts and one item of the dict is a date in m/d/Y
> format. I want to sort by that. I tried this:
> 
> sorted(data['trends'], key=lambda k:
> datetime.strptime(k['date_time'],'%m/%d/%Y'))
> 
> But that fails with:
> 
> Exception Type: AttributeError at /report/CDSEM/WaferAlignment/ajax/waChart.json
> Exception Value: 'module' object has no attribute 'strptime'
> 
> How can I do this sort?

You're not showing us all your code, so I can only make an assumption
that the "datetime" you are referencing is a module import.  Did you try
your sort function before you stuck it in a lambda?  Here's a attempt:

>>> import datetime
>>> datetime.strptime
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'module' object has no attribute 'strptime'

Looks like the same problem you encountered. So it has nothing to do
with sorting.  Quite literally, your datetime symbol does not contain
the attribute strptime like you thought it did.  I think you meant to
use datetime.datetime.strptime:

>>> import datetime
>>> datetime.datetime.strptime("01/02/2003","%m/%d/%Y")
datetime.datetime(2003, 1, 2, 0, 0)

Use the interactive interpreter to test out little things like this. It
will save you a lot of hassle later on.


From larry.martell at gmail.com  Tue Jan 31 15:39:40 2017
From: larry.martell at gmail.com (Larry Martell)
Date: Tue, 31 Jan 2017 15:39:40 -0500
Subject: sorting a list of dicts by a computed field
In-Reply-To: <CAPTjJmpaANExgin=i7bseBXhQpjFa_cZKiTNiC8gMCq78pXv3A@mail.gmail.com>
References: <CACwCsY5WucJ8AeP9MH_n+z9qqnRc7ZpfQ_tLQaieM5iCugOD2w@mail.gmail.com>
 <CAPTjJmpaANExgin=i7bseBXhQpjFa_cZKiTNiC8gMCq78pXv3A@mail.gmail.com>
Message-ID: <CACwCsY7aM_YkS-HacooLjcgo-wQDFgv=3jRABfPqHmrz8YJM-g@mail.gmail.com>

On Tue, Jan 31, 2017 at 3:30 PM, Chris Angelico <rosuav at gmail.com> wrote:
> On Wed, Feb 1, 2017 at 7:26 AM, Larry Martell <larry.martell at gmail.com> wrote:
>> I have a list of dicts and one item of the dict is a date in m/d/Y
>> format. I want to sort by that. I tried this:
>>
>> sorted(data['trends'], key=lambda k:
>> datetime.strptime(k['date_time'],'%m/%d/%Y'))
>>
>> But that fails with:
>>
>> Exception Type: AttributeError at /report/CDSEM/WaferAlignment/ajax/waChart.json
>> Exception Value: 'module' object has no attribute 'strptime'
>>
>> How can I do this sort?
>
> I think your problem here may be with how you're trying to parse that
> datetime. There are two common ways to get access to a thing called
> "datetime":
>
> # Option 1:
> import datetime
> # Option 2:
> from datetime import datetime
>
> The first one gives you a module; the second gives you just one class
> out of that module (one that happens to have the same name as the
> module itself). My guess is that you're using the first form, but you
> picked up some example code from somewhere that assumes the second.
>
> Try using "datetime.datetime.strptime" in your key function, and see
> if that helps.

Thanks. I knew that ;-) I've had a very long day, and I don't use
lambda much so I thought it was an issue with that.


From python at mrabarnett.plus.com  Tue Jan 31 15:43:14 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Tue, 31 Jan 2017 20:43:14 +0000
Subject: Python3.6 tkinter bug?
In-Reply-To: <CABie7_pjhkKRUmKWhpr-LTwSXqzGjZ8-YbbghYLRXmJ2YKTTmA@mail.gmail.com>
References: <CABie7_pjhkKRUmKWhpr-LTwSXqzGjZ8-YbbghYLRXmJ2YKTTmA@mail.gmail.com>
Message-ID: <ade33ec7-9a60-9a9e-f0d7-8079d959c119@mrabarnett.plus.com>

On 2017-01-31 19:18, George Trojan - NOAA Federal wrote:
> The following program behaves differently under Python 3.6:
>
> '''
> checkbutton test
> '''
>
> import tkinter
>
> class GUI(tkinter.Tk):
>     def __init__(self):
>         tkinter.Tk.__init__(self)
>         frame = tkinter.Frame(self)
>         for tag in ('A', 'B'):
>             w = tkinter.Checkbutton(frame, text=tag)
>             w.pack(side='top', padx=10, pady=10)
>             print(w)
>         frame.pack(side='top')
>         frame = tkinter.Frame(self)
>         for tag in ('C', 'D'):
>             w = tkinter.Checkbutton(frame, text=tag)
>             w.pack(side='top', padx=10, pady=10)
>             print(w)
>         frame.pack(side='top')
>
> gui = GUI()
> gui.mainloop()
>
> Selection of button 'A' also selects button 'C'. Same goes for 'B' and 'D'.
> I noticed that widget names have changed, which likely leads to the cause:
>
>> /usr/local/Python-3.5.1/bin/python3 foo.py
> .140182648425776.140182647743208
> .140182648425776.140182647841848
> .140182648424152.140182648282080
> .140182648424152.140182648282136
>
>> /usr/local/Python-3.6.0/bin/python3 foo.py
> .!frame.!checkbutton
> .!frame.!checkbutton2
> .!frame2.!checkbutton
> .!frame2.!checkbutton2
>
> Is this a known issue?
>
I don't believe so; at least, I couldn't see it in the bug tracker.

Presumably you'll want to check the values of the checkboxes, so you'll 
bind them to tkinter variables (IntVar, etc). When you do that, it works 
correctly.



From tjreedy at udel.edu  Tue Jan 31 16:11:48 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Tue, 31 Jan 2017 16:11:48 -0500
Subject: Python3.6 tkinter bug?
In-Reply-To: <ade33ec7-9a60-9a9e-f0d7-8079d959c119@mrabarnett.plus.com>
References: <CABie7_pjhkKRUmKWhpr-LTwSXqzGjZ8-YbbghYLRXmJ2YKTTmA@mail.gmail.com>
 <ade33ec7-9a60-9a9e-f0d7-8079d959c119@mrabarnett.plus.com>
Message-ID: <o6quig$tfi$1@blaine.gmane.org>

On 1/31/2017 3:43 PM, MRAB wrote:
> On 2017-01-31 19:18, George Trojan - NOAA Federal wrote:
>> The following program behaves differently under Python 3.6:
>>
>> '''
>> checkbutton test
>> '''
>>
>> import tkinter
>>
>> class GUI(tkinter.Tk):
>>     def __init__(self):
>>         tkinter.Tk.__init__(self)
>>         frame = tkinter.Frame(self)
>>         for tag in ('A', 'B'):
>>             w = tkinter.Checkbutton(frame, text=tag)
>>             w.pack(side='top', padx=10, pady=10)
>>             print(w)
>>         frame.pack(side='top')
>>         frame = tkinter.Frame(self)
>>         for tag in ('C', 'D'):
>>             w = tkinter.Checkbutton(frame, text=tag)
>>             w.pack(side='top', padx=10, pady=10)
>>             print(w)
>>         frame.pack(side='top')
>>
>> gui = GUI()
>> gui.mainloop()
>>
>> Selection of button 'A' also selects button 'C'. Same goes for 'B' and
>> 'D'.
>> I noticed that widget names have changed, which likely leads to the
>> cause:
>>
>>> /usr/local/Python-3.5.1/bin/python3 foo.py
>> .140182648425776.140182647743208
>> .140182648425776.140182647841848
>> .140182648424152.140182648282080
>> .140182648424152.140182648282136
>>
>>> /usr/local/Python-3.6.0/bin/python3 foo.py
>> .!frame.!checkbutton
>> .!frame.!checkbutton2
>> .!frame2.!checkbutton
>> .!frame2.!checkbutton2
>>
>> Is this a known issue?
>>
> I don't believe so; at least, I couldn't see it in the bug tracker.

Me neither.  I will open an issue on the tracker.

> Presumably you'll want to check the values of the checkboxes, so you'll
> bind them to tkinter variables (IntVar, etc). When you do that, it works
> correctly.
>


-- 
Terry Jan Reedy



From jladasky at itu.edu  Tue Jan 31 16:23:43 2017
From: jladasky at itu.edu (jladasky at itu.edu)
Date: Tue, 31 Jan 2017 13:23:43 -0800 (PST)
Subject: sorting a list of dicts by a computed field
In-Reply-To: <mailman.212.1485894866.2473.python-list@python.org>
References: <CACwCsY5WucJ8AeP9MH_n+z9qqnRc7ZpfQ_tLQaieM5iCugOD2w@mail.gmail.com>
 <b3d1a5e7-435e-b033-564f-66d58778da3d@mrabarnett.plus.com>
 <mailman.212.1485894866.2473.python-list@python.org>
Message-ID: <47e5beda-d536-4c7a-8c13-c61c18477058@googlegroups.com>

On Tuesday, January 31, 2017 at 12:34:38 PM UTC-8, MRAB wrote:
> On 2017-01-31 20:26, Larry Martell wrote:

> The module 'datetime' contains a class called 'datetime'. Judging by 
> your exception, 'datetime' is the module.
> 
> Try "datetime.datetime.strptime" instead.

This re-use of the name "datetime" has tripped me up more than once.  It's one of my few grumbles with the Python standard library.


From saxri89 at gmail.com  Tue Jan 31 16:29:43 2017
From: saxri89 at gmail.com (Xristos Xristoou)
Date: Tue, 31 Jan 2017 13:29:43 -0800 (PST)
Subject: DJANGO IMAGES QUESTION
Message-ID: <594dba52-5a04-4bb5-8cfd-0d87cf921b90@googlegroups.com>

who is the better method to take images from uses(visitors) on my web site
and to return the new images(processing) back to users using DJANGO?
i am new i dont know how to connect my python script with the html templetes to take the images and how to return?
for example my script take images paths to processing new images with new paths.


From jladasky at itu.edu  Tue Jan 31 16:34:32 2017
From: jladasky at itu.edu (jladasky at itu.edu)
Date: Tue, 31 Jan 2017 13:34:32 -0800 (PST)
Subject: Overriding True and False ?
In-Reply-To: <mailman.157.1485761360.2473.python-list@python.org>
References: <3F8981B9-4D4B-41B0-A864-24388A35F5FD@furrypants.com>
 <mailman.157.1485761360.2473.python-list@python.org>
Message-ID: <e0a32b30-d461-4fb9-9032-5e282fd5bfb5@googlegroups.com>

On Sunday, January 29, 2017 at 11:29:29 PM UTC-8, Irv Kalb wrote:

> It seems very odd that Python allows you to override the values of 
> True and False.

Hi Irv,

Let me join the chorus of people who are encouraging you to switch to Python3, which corrects this problem.  Overriding builtins has been judged harmful, and now it is a lot harder to do.

There are sometimes good reasons for shadowing builtins, but more than a few newcomers to Python (once upon a time, myself included) wrote buggy code by accident because of this surprising flexibility.

That being said, I can't resist re-posting a story from 14 years ago:

https://groups.google.com/forum/#!original/comp.lang.python/xEtUYsxLnFE/6yYgvhvkggMJ

==============

From: lad... at my-deja.com (John Ladasky)
Newsgroups: comp.lang.python
Subject: Re: Python 2.3 True = False
Date: 24 Mar 2003 12:29:04 -0800

an... at calbay.com (Anand) wrote in message news:<c6303995.0303... at posting.google.com>...
> >>> True = False
> >>> True
>  False

Shhh!  Anand!  You're not supposed to show anyone that!  Now every
politician on Earth will want to program in Python!

==============


From tjreedy at udel.edu  Tue Jan 31 16:38:09 2017
From: tjreedy at udel.edu (Terry Reedy)
Date: Tue, 31 Jan 2017 16:38:09 -0500
Subject: Python3.6 tkinter bug?
In-Reply-To: <o6quig$tfi$1@blaine.gmane.org>
References: <CABie7_pjhkKRUmKWhpr-LTwSXqzGjZ8-YbbghYLRXmJ2YKTTmA@mail.gmail.com>
 <ade33ec7-9a60-9a9e-f0d7-8079d959c119@mrabarnett.plus.com>
 <o6quig$tfi$1@blaine.gmane.org>
Message-ID: <o6r03s$97d$1@blaine.gmane.org>

On 1/31/2017 4:11 PM, Terry Reedy wrote:
> On 1/31/2017 3:43 PM, MRAB wrote:
>> On 2017-01-31 19:18, George Trojan - NOAA Federal wrote:
>>> The following program behaves differently under Python 3.6:
>>>
>>> '''
>>> checkbutton test
>>> '''
>>>
>>> import tkinter
>>>
>>> class GUI(tkinter.Tk):
>>>     def __init__(self):
>>>         tkinter.Tk.__init__(self)
>>>         frame = tkinter.Frame(self)
>>>         for tag in ('A', 'B'):
>>>             w = tkinter.Checkbutton(frame, text=tag)
>>>             w.pack(side='top', padx=10, pady=10)
>>>             print(w)
>>>         frame.pack(side='top')
>>>         frame = tkinter.Frame(self)
>>>         for tag in ('C', 'D'):
>>>             w = tkinter.Checkbutton(frame, text=tag)
>>>             w.pack(side='top', padx=10, pady=10)
>>>             print(w)
>>>         frame.pack(side='top')
>>>
>>> gui = GUI()
>>> gui.mainloop()
>>>
>>> Selection of button 'A' also selects button 'C'. Same goes for 'B' and
>>> 'D'.
>>> I noticed that widget names have changed, which likely leads to the
>>> cause:
>>>
>>>> /usr/local/Python-3.5.1/bin/python3 foo.py
>>> .140182648425776.140182647743208
>>> .140182648425776.140182647841848
>>> .140182648424152.140182648282080
>>> .140182648424152.140182648282136
>>>
>>>> /usr/local/Python-3.6.0/bin/python3 foo.py
>>> .!frame.!checkbutton
>>> .!frame.!checkbutton2
>>> .!frame2.!checkbutton
>>> .!frame2.!checkbutton2
>>>
>>> Is this a known issue?
>>>
>> I don't believe so; at least, I couldn't see it in the bug tracker.
>
> Me neither.  I will open an issue on the tracker.

https://bugs.python.org/issue29402

>> Presumably you'll want to check the values of the checkboxes, so you'll
>> bind them to tkinter variables (IntVar, etc). When you do that, it works
>> correctly.

This still seems like a bug to me.  Similar issue
https://bugs.python.org/issue25684 has the same workaround for ttk 
Option Menu radiobuttons.

-- 
Terry Jan Reedy



From greg.ewing at canterbury.ac.nz  Tue Jan 31 17:02:13 2017
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Wed, 01 Feb 2017 11:02:13 +1300
Subject: What are your opinions on .NET Core vs Python?
In-Reply-To: <mailman.206.1485884746.2473.python-list@python.org>
References: <CAAp0bGup1DOJBU0+52eqsb-XqOi6Pv1zGJ2bWvgUMtPuZ1v3YA@mail.gmail.com>
 <CAAp0bGvohNUsAo5v5A_FLFBKbXkyD+gUbqXtAEeGRhrHNG2xwA@mail.gmail.com>
 <6ade49f7-e0fa-90e0-7b47-ad5e14c391fe@gmail.com>
 <21c7475509634730811331fe2804cc0f@activenetwerx.com>
 <CAPjBxg87VFkDG5kKZ=1wKA6oBMUkP0Oja9PEzg8inQ78pWOnqg@mail.gmail.com>
 <mailman.194.1485827529.2473.python-list@python.org>
 <efalgnFu896U1@mid.individual.net>
 <CALwzid=J1DSx1dhxz+cskSECx2LYiBcf0N_7+PZCUdw2pndYAQ@mail.gmail.com>
 <CALwzid=FEf5z+CNpP81U84SPmz_gZ-j_OFe773tKsGDFxsLfMA@mail.gmail.com>
 <mailman.206.1485884746.2473.python-list@python.org>
Message-ID: <efcfr7FbgbjU1@mid.individual.net>

Ian Kelly wrote:
> Java also has "static import" which lets
> you individually import specific static methods or fields from a class.

Yes, but it's nowhere near as convenient as Python's import.
To import individual names you have to qualify all of them with
the whole package name, and there is no way to give them
different names locally.

-- 
Greg


From ceh329 at gmail.com  Tue Jan 31 17:11:10 2017
From: ceh329 at gmail.com (Charles Heizer)
Date: Tue, 31 Jan 2017 14:11:10 -0800 (PST)
Subject: Embedding python, run a function and get it's result
Message-ID: <1d151468-9d4f-4be7-8f36-c53131717b3e@googlegroups.com>

Hello,
I'm messing around with the embedded python and I can get parts to work. What I'm having a hard time is getting my head around calling a function in the python string and getting it's result.

Question, how do I load the python script and call runMe() and get it's value?

Thanks!

Example Works

Obj-C Code:

Py_Initialize();
PyObject *py_main, *py_dict;
py_main = PyImport_AddModule("__main__");
py_dict = PyModule_GetDict(py_main);
    
// Run the python source code
PyRun_String([auditScript UTF8String], Py_file_input, py_dict, py_dict);

PyObject *pythonString = PyDict_GetItemString(py_dict, "x") ;
if (!pythonString) {
        NSLog(@"pythonString returned NULL");
        return "NO";
}

// Convert the unpickled Python string to a C string
char *cString = PyString_AsString(pythonString);
Py_DECREF(pythonString);
f (!cString) {
    NSLog(@"Failed converting pythonString string to C string");
    return 1;
}
NSLog(@"answer: %@",[NSString cString]);

Python Code:

x = "NA"
def runMe():
	return "YES"

x = runMe()


From auriocus at gmx.de  Tue Jan 31 17:34:22 2017
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Tue, 31 Jan 2017 23:34:22 +0100
Subject: Python3.6 tkinter bug?
In-Reply-To: <mailman.208.1485890342.2473.python-list@python.org>
References: <CABie7_pjhkKRUmKWhpr-LTwSXqzGjZ8-YbbghYLRXmJ2YKTTmA@mail.gmail.com>
 <mailman.208.1485890342.2473.python-list@python.org>
Message-ID: <o6r3a7$ei1$1@dont-email.me>

Am 31.01.17 um 20:18 schrieb George Trojan - NOAA Federal:
> Selection of button 'A' also selects button 'C'. Same goes for 'B' and 'D'.
> I noticed that widget names have changed, which likely leads to the cause:
>
>> /usr/local/Python-3.5.1/bin/python3 foo.py
> .140182648425776.140182647743208
> .140182648425776.140182647841848
> .140182648424152.140182648282080
> .140182648424152.140182648282136
>
>> /usr/local/Python-3.6.0/bin/python3 foo.py
> .!frame.!checkbutton
> .!frame.!checkbutton2
> .!frame2.!checkbutton
> .!frame2.!checkbutton2

The widget names look fine to, and the 3.6 naming is way better, because 
it can be used for debugging more easily. The behaviour you describe can 
have two reasons, a) the same widget can be packed twice b) the widgets 
use the same variable. In Tk, a widget does not need an associate 
variable - which can be done by setting the variable to an empty string, 
or by leaving this option off.

Presumably Python 3.6 passes anything else than an empty string to Tk as 
the -variable option, maybe a mistranslated None? Can't test it myself, 
but in your example you could, for instance, check the output of 
self.call(w, 'configure'), which lists you the Tk side configuration, or 
self.call(w, 'configure', '-variable') to get specifically the bound 
variable.

	Christian



From kapitikusha at gmail.com  Tue Jan 31 17:34:58 2017
From: kapitikusha at gmail.com (Marvin Sinclair)
Date: Tue, 31 Jan 2017 14:34:58 -0800 (PST)
Subject: What's the best python projects book
Message-ID: <01584806-b34f-4261-a466-128269fd2f78@googlegroups.com>

Am a newbie to python, just to completed reading and practice a python book, but I wanted to know if there is a good python book that is composed of different projects on different topics that I can code along, read what is happening so i can gain more experience, please suggest me  any, or if you have it please email it to me 
Kapitikusha at gmail.com  i will so much appreciate


From python at mrabarnett.plus.com  Tue Jan 31 18:02:41 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Tue, 31 Jan 2017 23:02:41 +0000
Subject: Python3.6 tkinter bug?
In-Reply-To: <o6r3a7$ei1$1@dont-email.me>
References: <CABie7_pjhkKRUmKWhpr-LTwSXqzGjZ8-YbbghYLRXmJ2YKTTmA@mail.gmail.com>
 <mailman.208.1485890342.2473.python-list@python.org>
 <o6r3a7$ei1$1@dont-email.me>
Message-ID: <f332c3ae-958f-0c9c-8e25-b7d6486d605c@mrabarnett.plus.com>

On 2017-01-31 22:34, Christian Gollwitzer wrote:
> Am 31.01.17 um 20:18 schrieb George Trojan - NOAA Federal:
>> Selection of button 'A' also selects button 'C'. Same goes for 'B' and 'D'.
>> I noticed that widget names have changed, which likely leads to the cause:
>>
>>> /usr/local/Python-3.5.1/bin/python3 foo.py
>> .140182648425776.140182647743208
>> .140182648425776.140182647841848
>> .140182648424152.140182648282080
>> .140182648424152.140182648282136
>>
>>> /usr/local/Python-3.6.0/bin/python3 foo.py
>> .!frame.!checkbutton
>> .!frame.!checkbutton2
>> .!frame2.!checkbutton
>> .!frame2.!checkbutton2
>
> The widget names look fine to, and the 3.6 naming is way better, because
> it can be used for debugging more easily. The behaviour you describe can
> have two reasons, a) the same widget can be packed twice b) the widgets
> use the same variable. In Tk, a widget does not need an associate
> variable - which can be done by setting the variable to an empty string,
> or by leaving this option off.
>
> Presumably Python 3.6 passes anything else than an empty string to Tk as
> the -variable option, maybe a mistranslated None? Can't test it myself,
> but in your example you could, for instance, check the output of
> self.call(w, 'configure'), which lists you the Tk side configuration, or
> self.call(w, 'configure', '-variable') to get specifically the bound
> variable.
>
Perhaps someone who knows Tcl and tk can tell me, but I notice that in 
the first example, the second part of the widget names are unique, 
whereas in the second example, the second part of the widget names are 
the reused (both "!checkbutton" and "!checkbutton2" occur twice). Is 
that the cause?

Do the names need to be:

.!frame.!checkbutton
.!frame.!checkbutton2
.!frame2.!checkbutton3
.!frame2.!checkbutton4

?



From ben+python at benfinney.id.au  Tue Jan 31 18:39:21 2017
From: ben+python at benfinney.id.au (Ben Finney)
Date: Wed, 01 Feb 2017 10:39:21 +1100
Subject: command line micro wiki written in Python
References: <b0d91c15-62a2-4a76-9b46-c38d53d4e08d@googlegroups.com>
Message-ID: <8560kusst2.fsf@benfinney.id.au>

Paul Wolf <paulwolf333 at gmail.com> writes:

> I've created a command line utility for managing text files. It's
> written in Python: [?]

Thank you.

> The key aspects are 
>
> * Entirely command-line driven
>
> * Text documents only with a slight preference for Markdown

The Python community has a stronger (?) preference for reStructuredText
format. Can that be the default?

That is, I want my text files to be named ?foo? (no suffix) or ?foo.txt?
(because they're primarily text), and have the default be to parse them
as reStructuredText.

> I'd be interested in feedback if there is any interest in using this
> kind of utility. I'll expose a python API so bulk operations can be
> done easily on the command line or via scripts.

This is a great way to start!

-- 
 \       ?Science shows that belief in God is not only obsolete. It is |
  `\                        also incoherent.? ?Victor J. Stenger, 2001 |
_o__)                                                                  |
Ben Finney



From george.trojan at noaa.gov  Tue Jan 31 18:48:38 2017
From: george.trojan at noaa.gov (George Trojan - NOAA Federal)
Date: Tue, 31 Jan 2017 23:48:38 +0000
Subject: Python3.6 tkinter bug
Message-ID: <CABie7_qvizotHF8F8d18uk08kdKv5zbAObVZGyeKuuAuMg18+Q@mail.gmail.com>

On 2017-01-31 18:02, MRAB wrote:

On 2017-01-31 22:34, Christian Gollwitzer wrote:
> >* Am 31.01.17 um 20:18 schrieb George Trojan - NOAA Federal:
> *>>* Selection of button 'A' also selects button 'C'. Same goes for 'B' and 'D'.
> *>>* I noticed that widget names have changed, which likely leads to the cause:
> *>>
> >>>* /usr/local/Python-3.5.1/bin/python3 foo.py
> *>>* .140182648425776.140182647743208
> *>>* .140182648425776.140182647841848
> *>>* .140182648424152.140182648282080
> *>>* .140182648424152.140182648282136
> *>>
> >>>* /usr/local/Python-3.6.0/bin/python3 foo.py
> *>>* .!frame.!checkbutton
> *>>* .!frame.!checkbutton2
> *>>* .!frame2.!checkbutton
> *>>* .!frame2.!checkbutton2
> *>
> >* The widget names look fine to, and the 3.6 naming is way better, because
> *>* it can be used for debugging more easily. The behaviour you describe can
> *>* have two reasons, a) the same widget can be packed twice b) the widgets
> *>* use the same variable. In Tk, a widget does not need an associate
> *>* variable - which can be done by setting the variable to an empty string,
> *>* or by leaving this option off.
> *>
> >* Presumably Python 3.6 passes anything else than an empty string to Tk as
> *>* the -variable option, maybe a mistranslated None? Can't test it myself,
> *>* but in your example you could, for instance, check the output of
> *>* self.call(w, 'configure'), which lists you the Tk side configuration, or
> *>* self.call(w, 'configure', '-variable') to get specifically the bound
> *>* variable.
> *>
> Perhaps someone who knows Tcl and tk can tell me, but I notice that in
> the first example, the second part of the widget names are unique,
> whereas in the second example, the second part of the widget names are
> the reused (both "!checkbutton" and "!checkbutton2" occur twice). Is
> that the cause?
> Do the names need to be:
> .!frame.!checkbutton
> .!frame.!checkbutton2
> .!frame2.!checkbutton3
> .!frame2.!checkbutton4
> ?


Adding dummy variable solves the issue. Following Christian's
suggestion I added code to print Tk variable:

from functools import partial
import tkinter

class GUI(tkinter.Tk):
    def __init__(self):
        tkinter.Tk.__init__(self)
        frame = tkinter.Frame(self)
        for tag in ('A', 'B'):
            w = tkinter.Checkbutton(frame, text=tag, #
variable=tkinter.IntVar(),
                                    command=partial(print, tag))
            w.pack(side='top', padx=10, pady=10)
            print(tag, self.call(w, 'configure', '-variable'))
            print(w)
        frame.pack(side='top')
        frame = tkinter.Frame(self)
        for tag in ('C', 'D'):
            w = tkinter.Checkbutton(frame, text=tag, #
variable=tkinter.IntVar(),
                                    command=partial(print, tag))
            w.pack(side='top', padx=10, pady=10)
            print(tag, self.call(w, 'configure', '-variable'))
            print(w)
        frame.pack(side='top')

gui = GUI()
gui.mainloop()

The output is:

(venv-3.6.0) dilbert at gtrojan> python foo.py
A ('-variable', 'variable', 'Variable', '', <parsedVarName object:
'!checkbutton'>)
.!frame.!checkbutton
B ('-variable', 'variable', 'Variable', '', <parsedVarName object:
'!checkbutton2'>)
.!frame.!checkbutton2
C ('-variable', 'variable', 'Variable', '', <parsedVarName object:
'!checkbutton'>)
.!frame2.!checkbutton
D ('-variable', 'variable', 'Variable', '', <parsedVarName object:
'!checkbutton2'>)
.!frame2.!checkbutton2

It looks like the default name is the last component of widget tree.

When the # sign is removed, the names are unique and the problem disappears:

(venv-3.6.0) dilbert at gtrojan> python foo.py
A ('-variable', 'variable', 'Variable', '', <parsedVarName object: 'PY_VAR0'>)
.!frame.!checkbutton
B ('-variable', 'variable', 'Variable', '', <parsedVarName object: 'PY_VAR1'>)
.!frame.!checkbutton2
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From jaydesai834 at hotmail.com  Tue Jan 31 19:45:58 2017
From: jaydesai834 at hotmail.com (Jay Desai)
Date: Wed, 1 Feb 2017 00:45:58 +0000
Subject: SQL CE Database (.sdf) file connection with python
Message-ID: <DM5PR12MB19479FFF4F6405B06C5B37F5F84D0@DM5PR12MB1947.namprd12.prod.outlook.com>

Hello,


I came across a post from Nikhil Joshi at https://mail.python.org/pipermail/python-list/2014-November/681568.html.

*.sdf database access - mail.python.org<https://mail.python.org/pipermail/python-list/2014-November/681568.html>
mail.python.org
On Saturday, April 21, 2012 6:55:55 AM UTC-4, Alex Willmer wrote: > On Apr 19, 9:18 pm, Page3D wrote: > > Hi, I am trying to connect and access ...




I am facing the following problem. Can anyone please provide some guideline?

Problem Statement: Extract data stored in the .sdf file to python. System config: Win 10 Pro 64-bit, python 3.5.2-64 bit, adodbapi library, SQL CE 3.5

I am fairly new to programming and I have picked up Python as my first language to learn. Currently, I have hit a wall in process of connecting a SQL CE 3.5 .sdf file.

I have used the adodbapi library. I have searched the web extensively over the past week to find a solution to this problem and to make sure that my connection string is correct. I have tried multiple options/solutions provided on stack overflow and https://www.connectionstrings.com/microsoft-sqlserver-ce-oledb-3-5/.

Code:

import adodbapi

cons_str = "Provoider=Microsoft.SQLSERVER.MOBILE.OLEDB.3.5;" \
           "Data Source=D:\Work\Programming\Python\SQL_DataTransfer\LF.sdf;"\
           "Persist Security Info=False;" \
           "SSCE:Max Database Size=4091"

connection = adodbapi.connect(cons_str)
print(connection)

Error Message: Traceback (most recent call last): File "D:\Work\Programs\Python35.virtualenvs\sql_output\lib\site-packages\adodbapi\adodbapi.py", line 93, in make_COM_connecter c = Dispatch('ADODB.Connection') #connect after CoIninialize v2.1.1 adamvan NameError: name 'Dispatch' is not defined

During handling of the above exception, another exception occurred:

Traceback (most recent call last): File "D:\Work\Programs\Python35.virtualenvs\sql_output\lib\site-packages\adodbapi\adodbapi.py", line 112, in connect co.connect(kwargs) File "D:\Work\Programs\Python35.virtualenvs\sql_output\lib\site-packages\adodbapi\adodbapi.py", line 269, in connect self.connector = connection_maker() File "D:\Work\Programs\Python35.virtualenvs\sql_output\lib\site-packages\adodbapi\adodbapi.py", line 95, in make_COM_connecter raise api.InterfaceError ("Windows COM Error: Dispatch('ADODB.Connection') failed.") adodbapi.apibase.InterfaceError: Windows COM Error: Dispatch('ADODB.Connection') failed.

During handling of the above exception, another exception occurred:

Traceback (most recent call last): File "D:/Work/Programming/Python/SQL_DataTransfer/SQL_CE_reportDB.py", line 8, in connection = adodbapi.connect(cons_str) File "D:\Work\Programs\Python35.virtualenvs\sql_output\lib\site-packages\adodbapi\adodbapi.py", line 116, in connect raise api.OperationalError(e, message) adodbapi.apibase.OperationalError: (InterfaceError("Windows COM Error: Dispatch('ADODB.Connection') failed.",), 'Error opening connection to "Provoider=Microsoft.SQLSERVER.MOBILE.OLEDB.3.5;Data Source=D:\Work\Programming\Python\SQL_DataTransfer\LF.sdf;Persist Security Info=False;SSCE:Max Database Size=4091"')

At this point any help is much appreciated.

Thank you, Sincerely, JD.



From littledddna at gmail.com  Tue Jan 31 20:41:30 2017
From: littledddna at gmail.com (Xiao Zhang)
Date: Tue, 31 Jan 2017 15:41:30 -1000
Subject: Qtcore error problem
Message-ID: <CA+E8nA1QoWB_Fg-u=EJw8tKLFUhiVCkDrv6pVVQF-wVy0a+VcA@mail.gmail.com>

Dear python users,

I am new to python and now I met a problem. When I try to run a py file, I
got the following error:

    from vacumm.misc.grid.regridding import regrid2d
  File
"/home/xzhang3/usr/local/uvcdat/2.4.1/lib/python2.7/site-packages/vacumm/misc/__init__.py",
line 41, in <module>
    import color
  File
"/home/xzhang3/usr/local/uvcdat/2.4.1/lib/python2.7/site-packages/vacumm/misc/color.py",
line 50, in <module>
    import pylab as P

ImportError:
/home/xzhang3/usr/local/uvcdat/2.4.1/lib/python2.7/site-packages/PyQt4/QtCore.so:
undefined symbol: _ZN7QLocale14scriptToStringENS_6ScriptE

I searched the web and it looks like the problem has something to do with
different versions.
Any idea how to fix the problem ?  I am using python 2.7 now.


Really appreciate your ideas and best regards,


Xiao


From python at mrabarnett.plus.com  Tue Jan 31 22:12:08 2017
From: python at mrabarnett.plus.com (MRAB)
Date: Wed, 1 Feb 2017 03:12:08 +0000
Subject: SQL CE Database (.sdf) file connection with python
In-Reply-To: <DM5PR12MB19479FFF4F6405B06C5B37F5F84D0@DM5PR12MB1947.namprd12.prod.outlook.com>
References: <DM5PR12MB19479FFF4F6405B06C5B37F5F84D0@DM5PR12MB1947.namprd12.prod.outlook.com>
Message-ID: <4459f40e-1838-3f81-7bd9-0a928342b7b7@mrabarnett.plus.com>

On 2017-02-01 00:45, Jay Desai wrote:
> Hello,
>
>
> I came across a post from Nikhil Joshi at https://mail.python.org/pipermail/python-list/2014-November/681568.html.
>
> *.sdf database access - mail.python.org<https://mail.python.org/pipermail/python-list/2014-November/681568.html>
> mail.python.org
> On Saturday, April 21, 2012 6:55:55 AM UTC-4, Alex Willmer wrote: > On Apr 19, 9:18 pm, Page3D wrote: > > Hi, I am trying to connect and access ...
>
>
>
>
> I am facing the following problem. Can anyone please provide some guideline?
>
> Problem Statement: Extract data stored in the .sdf file to python. System config: Win 10 Pro 64-bit, python 3.5.2-64 bit, adodbapi library, SQL CE 3.5
>
> I am fairly new to programming and I have picked up Python as my first language to learn. Currently, I have hit a wall in process of connecting a SQL CE 3.5 .sdf file.
>
> I have used the adodbapi library. I have searched the web extensively over the past week to find a solution to this problem and to make sure that my connection string is correct. I have tried multiple options/solutions provided on stack overflow and https://www.connectionstrings.com/microsoft-sqlserver-ce-oledb-3-5/.
>
> Code:
>
> import adodbapi
>
> cons_str = "Provoider=Microsoft.SQLSERVER.MOBILE.OLEDB.3.5;" \
>            "Data Source=D:\Work\Programming\Python\SQL_DataTransfer\LF.sdf;"\
>            "Persist Security Info=False;" \
>            "SSCE:Max Database Size=4091"
>
I can a problem here. Your string contains "Provoider", which is a 
misspelling. It should be "Provider".

It would also be a good idea to make those 'raw' strings (prefix them 
with 'r') where they contain backslashes.

> connection = adodbapi.connect(cons_str)
> print(connection)
>
> Error Message: Traceback (most recent call last): File "D:\Work\Programs\Python35.virtualenvs\sql_output\lib\site-packages\adodbapi\adodbapi.py", line 93, in make_COM_connecter c = Dispatch('ADODB.Connection') #connect after CoIninialize v2.1.1 adamvan NameError: name 'Dispatch' is not defined
>
> During handling of the above exception, another exception occurred:
>
> Traceback (most recent call last): File "D:\Work\Programs\Python35.virtualenvs\sql_output\lib\site-packages\adodbapi\adodbapi.py", line 112, in connect co.connect(kwargs) File "D:\Work\Programs\Python35.virtualenvs\sql_output\lib\site-packages\adodbapi\adodbapi.py", line 269, in connect self.connector = connection_maker() File "D:\Work\Programs\Python35.virtualenvs\sql_output\lib\site-packages\adodbapi\adodbapi.py", line 95, in make_COM_connecter raise api.InterfaceError ("Windows COM Error: Dispatch('ADODB.Connection') failed.") adodbapi.apibase.InterfaceError: Windows COM Error: Dispatch('ADODB.Connection') failed.
>
> During handling of the above exception, another exception occurred:
>
> Traceback (most recent call last): File "D:/Work/Programming/Python/SQL_DataTransfer/SQL_CE_reportDB.py", line 8, in connection = adodbapi.connect(cons_str) File "D:\Work\Programs\Python35.virtualenvs\sql_output\lib\site-packages\adodbapi\adodbapi.py", line 116, in connect raise api.OperationalError(e, message) adodbapi.apibase.OperationalError: (InterfaceError("Windows COM Error: Dispatch('ADODB.Connection') failed.",), 'Error opening connection to "Provoider=Microsoft.SQLSERVER.MOBILE.OLEDB.3.5;Data Source=D:\Work\Programming\Python\SQL_DataTransfer\LF.sdf;Persist Security Info=False;SSCE:Max Database Size=4091"')
>
> At this point any help is much appreciated.
>
I've had a quick look on StackOverflow. I think you have to install pywin32.