From amonroe at columbus.rr.com  Tue Feb  3 13:27:55 2015
From: amonroe at columbus.rr.com (R. Alan Monroe)
Date: Tue, 3 Feb 2015 07:27:55 -0500
Subject: [CentralOH] =?utf-8?q?2015-01-30_=E9=81=93=E5=A0=B4_Scribbles_?=
 =?utf-8?b?76SY5pu4L+aDoeaWhz8gcXVvdGluZywgZG9jc3RyaW5ncywgaGVhcHEsIHNv?=
 =?utf-8?q?rted=2C_spam=2C_zen=2C_memoize=2C_recursion?=
In-Reply-To: <20150131150520.59199892.jep200404@columbus.rr.com>
References: <20150131150520.59199892.jep200404@columbus.rr.com>
Message-ID: <1225199478.20150203072755@columbus.rr.com>

The topic of online regex previewers came up last Friday. I just
stumbled across this one, which looks pretty handy.
http://jex.im/regulex/#!embed=false&flags=&re=^%28a|b%29*%3F%24

Alan


From eric at intellovations.com  Tue Feb  3 23:10:36 2015
From: eric at intellovations.com (Eric Floehr)
Date: Tue, 3 Feb 2015 17:10:36 -0500
Subject: [CentralOH] pandas cheat sheet and practical business python
In-Reply-To: <CAOoMBVip_p9SJYqfnSUApApcjjRROjAQWnV=1hpocVoSsFYeUw@mail.gmail.com>
References: <CAOoMBVip_p9SJYqfnSUApApcjjRROjAQWnV=1hpocVoSsFYeUw@mail.gmail.com>
Message-ID: <CAJzarMOj8Go8aLUnqEsLCOGMpmeRr6cxyikSo_1Q=LUO_PeJNA@mail.gmail.com>

Thanks for this list, Daniel! These are great resources which I will
definitely refer to. I have on my list to learn pandas for some weather
analysis I'm doing, which I've been told pandas would excel at.



On Sat, Jan 10, 2015 at 12:52 PM, pybokeh <pybokeh at gmail.com> wrote:

> Hello List,
> Thought I share my pandas cheat sheet that I have made that focuses on
> common data manipulations that I use at work:
>
> http://nbviewer.ipython.org/github/pybokeh/ipython_notebooks/blob/master/pandas/PandasCheatSheet.ipynb
>
> This is a notebook that someone else has made that shows how you could do
> some complex data filtering with pandas also:
> http://nbviewer.ipython.org/gist/phobson/6006004/selections.ipynb
>
> Also, this web site contains a few good examples of practical uses for
> Python:
> http://pbpython.com/
>
> Have a nice weekend!
>
> - Daniel
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150203/b4d74fb2/attachment.html>

From eric at intellovations.com  Thu Feb  5 02:39:37 2015
From: eric at intellovations.com (Eric Floehr)
Date: Wed, 4 Feb 2015 20:39:37 -0500
Subject: [CentralOH] Python Parsing Puzzle
In-Reply-To: <CAGbNH0p8rYepmB1FwFzV_HNOZjhc_H9FWWh2ksUdtayM5QbkZQ@mail.gmail.com>
References: <CAJzarMMsWR=TGBVh_-Q5cWunaG6dpxrtde2Ek=T_QsXbG-fyCg@mail.gmail.com>
 <20141206153401.37fbd230.jep200404@columbus.rr.com>
 <CAEie7+qYL5t2QawGURw9XkR-5kYywpRhi6Scuz4WUfshVJR-Mw@mail.gmail.com>
 <CAJShLf-qBK3eCek8RnbNbY_S9dzMFuACgbqKgOdPJH0V374Anw@mail.gmail.com>
 <CAGbNH0p8rYepmB1FwFzV_HNOZjhc_H9FWWh2ksUdtayM5QbkZQ@mail.gmail.com>
Message-ID: <CAJzarMOsathO2872PEftTjkCDjWSaHLGUBK7aRg3N_Owwg=0Sw@mail.gmail.com>

These are all great solutions! Quite a few different implementations, and
I'm glad everyone had fun with it. Just for closure, I realized I never
shared the solution that I created prior to posting the puzzle.

My solution was closest to XY's in that I used Python abstract syntax tree
parsing library (ast). This is the same code that parses Python code, and I
took advantage of the fact that the formulas were valid Python code (with a
little sanitizing, like XY did).

I ended up making a generator, that parsed the formula and returned pairs
of variable name and the coefficient, like so:


def coefficients(op):
    # Parse the string formula and turn into AST
    if isinstance(op, str):
        for coefficent in coefficients(ast.parse(op).body[0].value):
            yield coefficent
    # If there is only a number, it's the constant
    elif isinstance(op, ast.Num):
        yield 'CONST', op.n
    # If the operator is multiplication, it's a variable, coefficient pair
    elif isinstance(op.op, ast.Mult):
        yield op.right.id, op.left.n
    else:
        # We want all pairs to be added, so negate the coefficient if
subtraction
        if isinstance(op.op, ast.Sub):
            negate(op.right) # Just a helper function
        # Split the tree and work on each half
        for coefficient in itertools.chain(coefficients(op.left),
coefficients(op.right)):
            yield coefficient


You can pass in the string formula line, and use it like this:


for name, coefficient in coefficients(formula_string):
    ... do something ...


Thanks again everyone!



On Sun, Dec 7, 2014 at 3:34 PM, Erik Welch <erik.n.welch at gmail.com> wrote:

> Thanks for posting the puzzle, Eric.  It's great to see the different
> approaches people are taking.
>
> Here's my solution using regular expressions and pandas (which I'm sure
> could be cleaned up and simplified):
>
> http://nbviewer.ipython.org/url/pastebin.com/raw.php/%3Fi%3DS7fRWFwS
>
> Cheers,
> Erik
>
> On Sat, Dec 6, 2014 at 11:37 PM, Thomas Winningham <winningham at gmail.com>
> wrote:
>
>> I was curious about ast as well. I played with it once one time. So it is
>> true that parsing then shouldn't evaluate the code? I'm trying to think if
>> there are there any other possible "gotchas" ? I guess I should just read
>> more. I always figured things like Hy and PyPy make extensive use of
>> concepts in this general area. I played once on time with parser generators
>> in Java until I found a different solution for whatever I was doing. I
>> guess had I ever taken a compiler class I may know better how to Google
>> these things, or even post about them, heh.
>> On Dec 6, 2014 8:58 PM, "iynaix" <iynaix at gmail.com> wrote:
>>
>>> My solution: http://pastebin.com/nbGprTtV
>>>
>>> Quick explanation:
>>>
>>> As the formulas are basically valid python, minus undefined identifiers,
>>> I sanitize the formulas a little, then feed the formulas into the python
>>> ast module (https://docs.python.org/2/library/ast.html).
>>>
>>> Some quick walking of the parse tree yields the needed numbers and
>>> coefficients, which is then placed into a dict. Parsing an ast does not
>>> trigger an eval, so it should be safe, if that is a concern. After that
>>> it's just python data structure manipulation, pretty straightforward.
>>>
>>> This was pretty fun! Always wanted to play with the python ast module,
>>> but never had a problem to apply it on.
>>>
>>> Cheers,
>>> Xianyi
>>>
>>> On Sun, Dec 7, 2014 at 4:34 AM, <jep200404 at columbus.rr.com> wrote:
>>>
>>>> On Sat, 6 Dec 2014 10:59:21 -0500, Eric Floehr <eric at intellovations.com>
>>>> wrote:
>>>>
>>>> > How would you solve this problem?
>>>>
>>>> Release early, release often: http://colug.net/python/dojo/20141206/
>>>>
>>>> I would normally use grep, awk, sed, awk, tr, and friends,
>>>> but here's some very sloppy Python code to start things.
>>>>
>>>> What program, ala indent or cb, do folks like for cleaning up
>>>> Python code?
>>>> _______________________________________________
>>>> CentralOH mailing list
>>>> CentralOH at python.org
>>>> https://mail.python.org/mailman/listinfo/centraloh
>>>>
>>>
>>>
>>> _______________________________________________
>>> CentralOH mailing list
>>> CentralOH at python.org
>>> https://mail.python.org/mailman/listinfo/centraloh
>>>
>>>
>> _______________________________________________
>> CentralOH mailing list
>> CentralOH at python.org
>> https://mail.python.org/mailman/listinfo/centraloh
>>
>>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150204/cf2fd027/attachment.html>

From eric at intellovations.com  Thu Feb  5 02:55:14 2015
From: eric at intellovations.com (Eric Floehr)
Date: Wed, 4 Feb 2015 20:55:14 -0500
Subject: [CentralOH] Python Puzzle: Day generator
Message-ID: <CAJzarMNU8v_Gq4xCH7HS0mM0uOYMwfdj4rja3CYZ08dy6fN6bQ@mail.gmail.com>

Here is a group puzzle. I am interested in everyone's solutions. I will
post a link to my solution, which can also be refactored if you'd like a
refactoring challenge.

My timelapse code has a lot of places where I need to iterate through days.
So I thought to make a function that works like range() only with dates.

Here is the spec:

   1. Takes an optional start date, end date, and step.
   2. Start date and end date can either be python date objects or strings
   of form "YYYY-MM-DD"
   3. Step is number of days between steps, negative means step backwards
   4. If end date is greater than start date and step is not specified,
   step will be 1
   5. If start date is greater than end date and step is not specified,
   step will be -1
   6. If end date is not specified, it will be the same as start date
   7. If start date in not specified, it will be yesterday

Examples:

>>> for day in day_generator('2014-03-01', '2014-03-10'):
...     print day

2014-03-01
2014-03-02
2014-03-03
2014-03-04
2014-03-05
2014-03-06
2014-03-07
2014-03-08
2014-03-09
2014-03-10

>>> for day in day_generator('2014-11-16', '2014-10-31', -4):
...     print day

2014-11-16
2014-11-12
2014-11-08
2014-11-04
2014-10-31

And my solution (open to refactoring):
https://gist.github.com/efloehr/3e1dd639f3c5c1b064b7
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150204/1808d1f2/attachment.html>

From jep200404 at columbus.rr.com  Thu Feb  5 03:41:22 2015
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Wed, 4 Feb 2015 21:41:22 -0500
Subject: [CentralOH] Python Puzzle: Day generator
In-Reply-To: <CAJzarMNU8v_Gq4xCH7HS0mM0uOYMwfdj4rja3CYZ08dy6fN6bQ@mail.gmail.com>
References: <CAJzarMNU8v_Gq4xCH7HS0mM0uOYMwfdj4rja3CYZ08dy6fN6bQ@mail.gmail.com>
Message-ID: <20150204214122.60490b1c.jep200404@columbus.rr.com>

On Wed, 4 Feb 2015 20:55:14 -0500, Eric Floehr <eric at intellovations.com> wrote:

> Here is a group puzzle. 

> My timelapse code has a lot of places where I need to iterate through days.

What type should the generated objects be? 
    str?
    datetime.date? (for which print yields different output)

Sometimes, once I see some solution, it's hard to imagine 
other approaches, so I am avoiding looking at your code 
until I've written my own. 

From andrewcfitzgerald at gmail.com  Thu Feb  5 04:28:18 2015
From: andrewcfitzgerald at gmail.com (Andrew Fitzgerald)
Date: Wed, 4 Feb 2015 22:28:18 -0500
Subject: [CentralOH] Python Puzzle: Day generator
In-Reply-To: <CAJzarMNU8v_Gq4xCH7HS0mM0uOYMwfdj4rja3CYZ08dy6fN6bQ@mail.gmail.com>
References: <CAJzarMNU8v_Gq4xCH7HS0mM0uOYMwfdj4rja3CYZ08dy6fN6bQ@mail.gmail.com>
Message-ID: <CACkx_dD5DS8KS39OTZPcfYhYxXGPV+HuLyNk4hB+1FwM2XyX_w@mail.gmail.com>

One small change to your gist:
https://gist.github.com/Fitzoh/4f698d5014b3768ebbeb/revisions

On Wed, Feb 4, 2015 at 8:55 PM, Eric Floehr <eric at intellovations.com> wrote:

> Here is a group puzzle. I am interested in everyone's solutions. I will
> post a link to my solution, which can also be refactored if you'd like a
> refactoring challenge.
>
> My timelapse code has a lot of places where I need to iterate through
> days. So I thought to make a function that works like range() only with
> dates.
>
> Here is the spec:
>
>    1. Takes an optional start date, end date, and step.
>    2. Start date and end date can either be python date objects or
>    strings of form "YYYY-MM-DD"
>    3. Step is number of days between steps, negative means step backwards
>    4. If end date is greater than start date and step is not specified,
>    step will be 1
>    5. If start date is greater than end date and step is not specified,
>    step will be -1
>    6. If end date is not specified, it will be the same as start date
>    7. If start date in not specified, it will be yesterday
>
> Examples:
>
> >>> for day in day_generator('2014-03-01', '2014-03-10'):
> ...     print day
>
> 2014-03-01
> 2014-03-02
> 2014-03-03
> 2014-03-04
> 2014-03-05
> 2014-03-06
> 2014-03-07
> 2014-03-08
> 2014-03-09
> 2014-03-10
>
> >>> for day in day_generator('2014-11-16', '2014-10-31', -4):
> ...     print day
>
> 2014-11-16
> 2014-11-12
> 2014-11-08
> 2014-11-04
> 2014-10-31
>
> And my solution (open to refactoring):
> https://gist.github.com/efloehr/3e1dd639f3c5c1b064b7
>
>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150204/c40981e7/attachment-0001.html>

From jep200404 at columbus.rr.com  Thu Feb  5 08:06:01 2015
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Thu, 5 Feb 2015 02:06:01 -0500
Subject: [CentralOH] Python Puzzle: Day generator
In-Reply-To: <CAJzarMNU8v_Gq4xCH7HS0mM0uOYMwfdj4rja3CYZ08dy6fN6bQ@mail.gmail.com>
References: <CAJzarMNU8v_Gq4xCH7HS0mM0uOYMwfdj4rja3CYZ08dy6fN6bQ@mail.gmail.com>
Message-ID: <20150205020601.3add0fb5.jep200404@columbus.rr.com>

On Wed, 4 Feb 2015 20:55:14 -0500, Eric Floehr <eric at intellovations.com> wrote:

> Here is a group puzzle. I am interested in everyone's solutions.

> ... I need to iterate through days.
> So I thought to make a function that works like range() only with dates.

See http://colug.net/python/cohpy/20150205/
for what I did before looking at your code.

> And my solution (open to refactoring):
> https://gist.github.com/efloehr/3e1dd639f3c5c1b064b7

Here's some refactoring comments, and comparison to my code, 
particularly of my cell #5.

First, some easy PEP 8 stuff:

    Use isinstance() instead of type() == str
    Delete the spaces inside the [] of your comprehensions

I like day= in timedelta(day=1) in your code. It documents the value.
Likewise for days= at the bottom.

.strptime() in my code makes short work of parsing YYYY-MM-DD strings.
Your start_day is None is more correct than my not start_date.

Because of your range test, I see that your loop only goes once 
for bad step polarities, instead of the infinite loop I feared.
It would be good to tighten up the specification for what 
behavior is desired for whacko step polarity. Does the 
polarity handling in your day_generator() make your other 
code do nothing gracefully? 

The names range_start and range_end are misleading. 
Better names would be range_min and range_max.

Looking at your min()/max() lines, I wish there were a minmax() 
function that returned a tuple, kind of like divmod() does for 
division.

Can your while loop be simplified to the following?

    while range_min <= current_day <= range_max:

I like the way that testing against both the min and max, 
avoids the need to figure out which single test would suffice.

Doing from datetime import in your code made your other code 
easier to read than mine.

Even though my having d and start_date refer to the same object 
causes no bug, your current_day = copy(start_day) is more prudent 
than my d = start_date. Of course, I could just claim that d 
is a pronoun for start_date. :-)

Your day_step is a better argument name than my terse step, 
because yours documents the value better.

I'm a little surprised I did not take advantage of elif for 
my isinstance() code.

What else did I miss?

From iynaix at gmail.com  Thu Feb  5 08:19:57 2015
From: iynaix at gmail.com (iynaix)
Date: Thu, 5 Feb 2015 15:19:57 +0800
Subject: [CentralOH] Python Puzzle: Day generator
In-Reply-To: <20150205020601.3add0fb5.jep200404@columbus.rr.com>
References: <CAJzarMNU8v_Gq4xCH7HS0mM0uOYMwfdj4rja3CYZ08dy6fN6bQ@mail.gmail.com>
 <20150205020601.3add0fb5.jep200404@columbus.rr.com>
Message-ID: <CAEie7+pwY9ew0D-+Gg-L2GjJbKsLrBn69pY8vKEcu00Tn_Tsow@mail.gmail.com>

Use isinstance(x, basestring) instead of isinstance(x, str) for python 2.x
as basestring handles both 'str' and 'unicode' string types in python 2.x.

This is not needed in python 3.x since all strings are now unicode and
there is only one 'str' to rule them all.

More detailed explanation and example here:

http://stackoverflow.com/a/1979107

Cheers,
XY

On Thu, Feb 5, 2015 at 3:06 PM, <jep200404 at columbus.rr.com> wrote:

> On Wed, 4 Feb 2015 20:55:14 -0500, Eric Floehr <eric at intellovations.com>
> wrote:
>
> > Here is a group puzzle. I am interested in everyone's solutions.
>
> > ... I need to iterate through days.
> > So I thought to make a function that works like range() only with dates.
>
> See http://colug.net/python/cohpy/20150205/
> for what I did before looking at your code.
>
> > And my solution (open to refactoring):
> > https://gist.github.com/efloehr/3e1dd639f3c5c1b064b7
>
> Here's some refactoring comments, and comparison to my code,
> particularly of my cell #5.
>
> First, some easy PEP 8 stuff:
>
>     Use isinstance() instead of type() == str
>     Delete the spaces inside the [] of your comprehensions
>
> I like day= in timedelta(day=1) in your code. It documents the value.
> Likewise for days= at the bottom.
>
> .strptime() in my code makes short work of parsing YYYY-MM-DD strings.
> Your start_day is None is more correct than my not start_date.
>
> Because of your range test, I see that your loop only goes once
> for bad step polarities, instead of the infinite loop I feared.
> It would be good to tighten up the specification for what
> behavior is desired for whacko step polarity. Does the
> polarity handling in your day_generator() make your other
> code do nothing gracefully?
>
> The names range_start and range_end are misleading.
> Better names would be range_min and range_max.
>
> Looking at your min()/max() lines, I wish there were a minmax()
> function that returned a tuple, kind of like divmod() does for
> division.
>
> Can your while loop be simplified to the following?
>
>     while range_min <= current_day <= range_max:
>
> I like the way that testing against both the min and max,
> avoids the need to figure out which single test would suffice.
>
> Doing from datetime import in your code made your other code
> easier to read than mine.
>
> Even though my having d and start_date refer to the same object
> causes no bug, your current_day = copy(start_day) is more prudent
> than my d = start_date. Of course, I could just claim that d
> is a pronoun for start_date. :-)
>
> Your day_step is a better argument name than my terse step,
> because yours documents the value better.
>
> I'm a little surprised I did not take advantage of elif for
> my isinstance() code.
>
> What else did I miss?
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150205/02da5963/attachment.html>

From jep200404 at columbus.rr.com  Thu Feb  5 09:19:30 2015
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Thu, 5 Feb 2015 03:19:30 -0500
Subject: [CentralOH] Python Puzzle: Day generator: Merged
In-Reply-To: <20150205020601.3add0fb5.jep200404@columbus.rr.com>
References: <CAJzarMNU8v_Gq4xCH7HS0mM0uOYMwfdj4rja3CYZ08dy6fN6bQ@mail.gmail.com>
 <20150205020601.3add0fb5.jep200404@columbus.rr.com>
Message-ID: <20150205031930.76dd97da.jep200404@columbus.rr.com>

On Thu, 5 Feb 2015 02:06:01 -0500, jep200404 at columbus.rr.com wrote:

> On Wed, 4 Feb 2015 20:55:14 -0500, Eric Floehr <eric at intellovations.com> wrote:
> 
> > Here is a group puzzle. I am interested in everyone's solutions.
> 
> > ... I need to iterate through days.
> > So I thought to make a function that works like range() only with dates.
> 
> See http://colug.net/python/cohpy/20150205/
> for what I did before looking at your code.

> > And my solution (open to refactoring):
> > https://gist.github.com/efloehr/3e1dd639f3c5c1b064b7

New code merges Eric's and my ideas.

    http://nbviewer.ipython.org/url/colug.net/python/cohpy/20150205/cohpy-20150205-day-generator-20150205-0255.ipynb
    http://colug.net/python/cohpy/20150205/cohpy-20150205-day-generator-20150205-0255.ipynb

> I like day= in timedelta(day=1) in your code. It documents the value.
> Likewise for days= at the bottom.

Was day= (instead of days=) a bug? 

What else did I miss?

From eric at intellovations.com  Thu Feb  5 13:42:42 2015
From: eric at intellovations.com (Eric Floehr)
Date: Thu, 5 Feb 2015 07:42:42 -0500
Subject: [CentralOH] Python Puzzle: Day generator: Merged
In-Reply-To: <20150205031930.76dd97da.jep200404@columbus.rr.com>
References: <CAJzarMNU8v_Gq4xCH7HS0mM0uOYMwfdj4rja3CYZ08dy6fN6bQ@mail.gmail.com>
 <20150205020601.3add0fb5.jep200404@columbus.rr.com>
 <20150205031930.76dd97da.jep200404@columbus.rr.com>
Message-ID: <CAJzarMMg+hRro4qSOfmYtxQfWWzuPf+xOW7oGk-OFemyooqPfg@mail.gmail.com>

On Thu, Feb 5, 2015 at 3:19 AM, <jep200404 at columbus.rr.com> wrote:

>
> Was day= (instead of days=) a bug?
>


I could say I deliberately added that as a test to see how many people
caught it :-D.

In reality, it is a bug, and makes very apparent my lack of a test case
that exercises that branch of the code. Whoops... I'll just exit slowly
now...
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150205/f683a03f/attachment.html>

From jep200404 at columbus.rr.com  Thu Feb  5 15:10:13 2015
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Thu, 5 Feb 2015 09:10:13 -0500
Subject: [CentralOH] basestring not found in Learning Python
In-Reply-To: <CAEie7+pwY9ew0D-+Gg-L2GjJbKsLrBn69pY8vKEcu00Tn_Tsow@mail.gmail.com>
References: <CAJzarMNU8v_Gq4xCH7HS0mM0uOYMwfdj4rja3CYZ08dy6fN6bQ@mail.gmail.com>
 <20150205020601.3add0fb5.jep200404@columbus.rr.com>
 <CAEie7+pwY9ew0D-+Gg-L2GjJbKsLrBn69pY8vKEcu00Tn_Tsow@mail.gmail.com>
Message-ID: <20150205091013.13281e96.jep200404@columbus.rr.com>

On Thu, 5 Feb 2015 15:19:57 +0800, iynaix <iynaix at gmail.com> wrote:

> Use isinstance(x, basestring) instead of isinstance(x, str) for python 2.x

Thanks. This seems to not be explained in Learning Python.
I am surprised that I am not able to find an instance of basestring in 
Learning Python 5th edition. 

From joe at joeshaw.org  Thu Feb  5 15:59:11 2015
From: joe at joeshaw.org (Joe Shaw)
Date: Thu, 5 Feb 2015 09:59:11 -0500
Subject: [CentralOH] Python Puzzle: Day generator
In-Reply-To: <CAJzarMNU8v_Gq4xCH7HS0mM0uOYMwfdj4rja3CYZ08dy6fN6bQ@mail.gmail.com>
References: <CAJzarMNU8v_Gq4xCH7HS0mM0uOYMwfdj4rja3CYZ08dy6fN6bQ@mail.gmail.com>
Message-ID: <CAOxvq7yg2e=W+6vfTDzb93CPAdP8Og12sydnqNAfz=s-w58vfQ@mail.gmail.com>

Hi,

Here's my solution, although I didn't read the spec carefully before I
wrote it so it behaves incorrectly:

https://gist.github.com/joeshaw/3e4172b5adc034a9771b

Oops.

Namely, if end_date is not specified, the generator yields forever and if
start_date is not specified, it is today.  It also always assumes a step of
1, so an end_date in the past without explicit step=-1 results in zero
values being yielded... that's a side effect of the infinite iteration.

Joe

On Wed, Feb 4, 2015 at 8:55 PM, Eric Floehr <eric at intellovations.com> wrote:

> Here is a group puzzle. I am interested in everyone's solutions. I will
> post a link to my solution, which can also be refactored if you'd like a
> refactoring challenge.
>
> My timelapse code has a lot of places where I need to iterate through
> days. So I thought to make a function that works like range() only with
> dates.
>
> Here is the spec:
>
>    1. Takes an optional start date, end date, and step.
>    2. Start date and end date can either be python date objects or
>    strings of form "YYYY-MM-DD"
>    3. Step is number of days between steps, negative means step backwards
>    4. If end date is greater than start date and step is not specified,
>    step will be 1
>    5. If start date is greater than end date and step is not specified,
>    step will be -1
>    6. If end date is not specified, it will be the same as start date
>    7. If start date in not specified, it will be yesterday
>
> Examples:
>
> >>> for day in day_generator('2014-03-01', '2014-03-10'):
> ...     print day
>
> 2014-03-01
> 2014-03-02
> 2014-03-03
> 2014-03-04
> 2014-03-05
> 2014-03-06
> 2014-03-07
> 2014-03-08
> 2014-03-09
> 2014-03-10
>
> >>> for day in day_generator('2014-11-16', '2014-10-31', -4):
> ...     print day
>
> 2014-11-16
> 2014-11-12
> 2014-11-08
> 2014-11-04
> 2014-10-31
>
> And my solution (open to refactoring):
> https://gist.github.com/efloehr/3e1dd639f3c5c1b064b7
>
>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150205/d050a10e/attachment.html>

From jep200404 at columbus.rr.com  Thu Feb  5 17:02:00 2015
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Thu, 5 Feb 2015 11:02:00 -0500
Subject: [CentralOH] Python Puzzle: Day generator: Factor Out Arg
 Parsing, Simplify Loop Test
In-Reply-To: <CAOxvq7yg2e=W+6vfTDzb93CPAdP8Og12sydnqNAfz=s-w58vfQ@mail.gmail.com>
References: <CAJzarMNU8v_Gq4xCH7HS0mM0uOYMwfdj4rja3CYZ08dy6fN6bQ@mail.gmail.com>
 <CAOxvq7yg2e=W+6vfTDzb93CPAdP8Og12sydnqNAfz=s-w58vfQ@mail.gmail.com>
Message-ID: <20150205110200.2dea630e.jep200404@columbus.rr.com>

On Thu, 5 Feb 2015 09:59:11 -0500, Joe Shaw <joe at joeshaw.org> wrote:

> https://gist.github.com/joeshaw/3e4172b5adc034a9771b

I had not thought of factoring out the parsing of date arguments 
as you did. Doing so yields:

def _parse_date_argument(date_, default):
    if date_ is None:
        date_ = default
    elif isinstance(date_, str):
        date_ = datetime.strptime(date_, '%Y-%m-%d').date()
    return date_

def day_generator(start_date=None, end_date=None, day_step=1):
    yesterday = date.today() - timedelta(days=1)
    start_date = _parse_date_argument(start_date, yesterday)
    end_date = _parse_date_argument(end_date, start_date)

    day_step = timedelta(abs(day_step))
    if end_date < start_date:
        day_step = -day_step
        
    min_date = min(start_date, end_date)
    max_date = max(start_date, end_date)

    # print(start_date, end_date, day_step, min_date, max_date)

    d = copy(start_date)
    while min_date <= d <= max_date:
        yield d
        d += day_step

>From https://gist.github.com/joeshaw/3e4172b5adc034a9771b

    while True:
        if not _in_range(d):
            break
        ...

can be simplified as:

    while _in_range(d):
        ...

How does your code behave if your day_generator is passed 
a datetime.date object for date arguments (as compared to 
passing a datetime.datetime object)?

From joe at joeshaw.org  Thu Feb  5 17:19:42 2015
From: joe at joeshaw.org (Joe Shaw)
Date: Thu, 5 Feb 2015 11:19:42 -0500
Subject: [CentralOH] Python Puzzle: Day generator: Factor Out Arg
 Parsing, Simplify Loop Test
In-Reply-To: <20150205110200.2dea630e.jep200404@columbus.rr.com>
References: <CAJzarMNU8v_Gq4xCH7HS0mM0uOYMwfdj4rja3CYZ08dy6fN6bQ@mail.gmail.com>
 <CAOxvq7yg2e=W+6vfTDzb93CPAdP8Og12sydnqNAfz=s-w58vfQ@mail.gmail.com>
 <20150205110200.2dea630e.jep200404@columbus.rr.com>
Message-ID: <CAOxvq7zqT0o5ouPoPSy4HJYMf7qzUKUdxvZbvvKnBkn=C1CMMQ@mail.gmail.com>

Hi,

On Thu, Feb 5, 2015 at 11:02 AM, <jep200404 at columbus.rr.com> wrote:
>
> How does your code behave if your day_generator is passed
> a datetime.date object for date arguments (as compared to
> passing a datetime.datetime object)?
>

It blows up.  I've fixed it in the gist.

Thanks,
Joe
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150205/5417d559/attachment.html>

From jmknapp at gmail.com  Thu Feb  5 21:53:55 2015
From: jmknapp at gmail.com (Joe Knapp)
Date: Thu, 5 Feb 2015 15:53:55 -0500
Subject: [CentralOH] Python Puzzle: Day generator
In-Reply-To: <CAOxvq7yg2e=W+6vfTDzb93CPAdP8Og12sydnqNAfz=s-w58vfQ@mail.gmail.com>
References: <CAJzarMNU8v_Gq4xCH7HS0mM0uOYMwfdj4rja3CYZ08dy6fN6bQ@mail.gmail.com>
 <CAOxvq7yg2e=W+6vfTDzb93CPAdP8Og12sydnqNAfz=s-w58vfQ@mail.gmail.com>
Message-ID: <CALwn+da__7AGz9CpY0fSAr+Pykq4k-CLvs7abXq3f1Dv6_CGeQ@mail.gmail.com>

Thinking about taking this 9-week edX/MITx course starting March 5:

Introduction to Computational Thinking and Data Science (with python)

https://www.edx.org/course/introduction-computational-thinking-data-mitx-6-00-2x-0#.VNPWbGjnQ2s

Joe

From jep200404 at columbus.rr.com  Sat Feb  7 22:08:55 2015
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Sat, 7 Feb 2015 16:08:55 -0500
Subject: [CentralOH] =?utf-8?q?2015-02-06_=E9=81=93=E5=A0=B4_Scribbles_?=
 =?utf-8?b?76SY5pu4L+aDoeaWhz8gZGphbmdvLCBldWxlciAjMTIsICMyLCByZXByIGFi?=
 =?utf-8?q?use=2C_factors=2C_interference=2C_moire=2C_heterodyning=2C_numb?=
 =?utf-8?q?ers_in_the_attic?=
Message-ID: <20150207160855.7bc5e8f4.jep200404@columbus.rr.com>

Party #1

    https://pypi.python.org/pypi/pandas

Party #2

    had many questions about Django, needs to do homework

    You read book:
    http://www.djangobook.com/en/2.0/index.html
        Chapters 1 through 8 inclusive
        Chapter 14 for session stuff
    sqlite3

    In restrospect, for the person's limited needs, maybe Django is overkill.

Party #3

    https://projecteuler.net/problem=2

        generate even fibonacci numbers
        [CentralOH] 2013-05-30 ?? Scribbles ??/???
        https://mail.python.org/pipermail/centraloh/2013-June/001698.html
        http://mail.python.org/pipermail/centraloh/attachments/20130531/f0ee5532/attachment.obj

        nested generators and tuple unpacking
        [CentralOH] 2013-06-07 ?? Scribbles ??/???
        https://mail.python.org/pipermail/centraloh/2013-June/001718.html

        Put code from both elegant nested generator technique and 
        plain functions in one ipython notebook.
        See http://colug.net/python/dojo/20150206.

    http://hackertyper.net/  # Air guitar for typing.

    Brandon rhodes' adventure
    http://pyvideo.org/video/522/pyohio-2011--sunday-lightning-talks
    http://pyvideo.org/video/522/
    See http://colug.net/python/dojo/20150206 for abusing __repr__().

    vim

        ^Wv to split existing pane into two panes side by side
            cursor stays in left pane
        ^Ws to split existing pane into two panes one above other
            cursor stays in top pane

Party #4

    Euler #12
        factor() was terribly slow
        Play with http://linux.die.net/man/1/factor.
        Need to work through examples by hand.
        How many factors do the following numbers have?
Korean Air Lines Flight 007
            2
            4
            8
            16
            32
            64

                What pattern do you see?

            3
            9Korean Air Lines Flight 007
            27
            81
            243

                What pattern do you see?

            6
            12
            24
            48
            96

                What pattern do you see?

            6
            18
            54
            162


                What pattern do you see?

            4
            12
            36
            108
            324

                What pattern do you see?

            Have you seen enough patterns to figure out a formula for 
            determining how many factors a number has?

    Did not have Ipython Notebook installed, so used tmpnb.org, 
    but lousy Wifi frustrated that.

    Wifi reception at Panera
    wp:Interference (wave propagation)
    wp:Node (physics)
    wp:Standing wave
    wp:Reflections of signals on conducting lines

wp:Radio_Shack#2015_Bankruptcy

http://opensource.com/business/15/2/how-linux-philosophy-affects-you

http://www.linuxlinks.com/article/20150201134045961/BeginnerBooks.html

What do you get when you combined Uber with Car2Go?

wp:???
http://en.wiktionary.org/wiki/?#Usage_notes
wp:Tally_marks#Clustering
wp:Attic
wp:Attic numerals
wp:Greek numerals
wp:Roman numerals
wp:Arabic numerals
wp:Hindu?Arabic numeral system

wp:hanjin
http://english.chosun.com/site/data/html_dir/2015/02/03/2015020301467.html
wp:Korean Air Lines Flight 007
wp:Korean Air Flight 801
wp:Shin Ki-ha
https://en.wiktionary.org/wiki/?
wp:Shin Ramyun

Eddie Harris - Listen Here - The Electrifying Eddie Harris
Desert Queen - Janet Wallach

From pybokeh at gmail.com  Fri Feb 13 15:32:26 2015
From: pybokeh at gmail.com (pybokeh)
Date: Fri, 13 Feb 2015 06:32:26 -0800
Subject: [CentralOH] conda.io - using conda for virtual environments and
	package management
Message-ID: <CAOoMBVgMO9YrgxkY=3PpL8S=Aa62_44ZneLj_QRVO+b+8sxeFQ@mail.gmail.com>

Hello List,
I know virtualenv gets a lot of mention for making virtual environments,
but I recommend conda instead.  Check out http://conda.io/ for more info.

- Daniel
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150213/d2d9329c/attachment.html>

From eric at intellovations.com  Fri Feb 13 15:38:19 2015
From: eric at intellovations.com (Eric Floehr)
Date: Fri, 13 Feb 2015 09:38:19 -0500
Subject: [CentralOH] conda.io - using conda for virtual environments and
 package management
In-Reply-To: <CAOoMBVgMO9YrgxkY=3PpL8S=Aa62_44ZneLj_QRVO+b+8sxeFQ@mail.gmail.com>
References: <CAOoMBVgMO9YrgxkY=3PpL8S=Aa62_44ZneLj_QRVO+b+8sxeFQ@mail.gmail.com>
Message-ID: <CAJzarMOdsNYwQYyhfn3EUWKvjJ5N8ZQO6D8VQUi5sRz+BrXrjw@mail.gmail.com>

Hi Daniel,

What are the things you like about conda over virtualenv?

-Eric


On Fri, Feb 13, 2015 at 9:32 AM, pybokeh <pybokeh at gmail.com> wrote:

> Hello List,
> I know virtualenv gets a lot of mention for making virtual environments,
> but I recommend conda instead.  Check out http://conda.io/ for more info.
>
> - Daniel
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150213/0eb55429/attachment.html>

From pybokeh at gmail.com  Fri Feb 13 16:20:25 2015
From: pybokeh at gmail.com (pybokeh)
Date: Fri, 13 Feb 2015 07:20:25 -0800
Subject: [CentralOH] conda.io - using conda for virtual environments and
 package management
In-Reply-To: <CAJzarMOdsNYwQYyhfn3EUWKvjJ5N8ZQO6D8VQUi5sRz+BrXrjw@mail.gmail.com>
References: <CAOoMBVgMO9YrgxkY=3PpL8S=Aa62_44ZneLj_QRVO+b+8sxeFQ@mail.gmail.com>
 <CAJzarMOdsNYwQYyhfn3EUWKvjJ5N8ZQO6D8VQUi5sRz+BrXrjw@mail.gmail.com>
Message-ID: <CAOoMBVioN=ubo9-0yinDOamRLGBbQSKY+dUXJLY8s7UiEP_sZQ@mail.gmail.com>

I think the real advantage is if you are on  Windows or don't want to
compile packages from source.  Since conda is part of Anaconda
distribution, there are already many popular pre-compiled binaries readily
available and Continuum IO the company behind Anaconda usually do a decent
job of quickly getting the latest version of their packages pushed out.  If
a package is not available in Anaconda, you can still install it using pip.

Also this is subjective, but I prefer the conda's more user-friendly
command line arguments over virtualenv's commands.  For example, if you
want to create an environment for a specific python version, in conda it is
just python=2.7 or python=3.4 whereas in virtualenv, you have to provide
the full path to the python interpreter.

This is about all I can think of off the top of my head.  I used to use
virtualenv, but I guess I got less patient over the years waiting on
compiling a package from source.

- Daniel
On Feb 13, 2015 9:38 AM, "Eric Floehr" <eric at intellovations.com> wrote:

> Hi Daniel,
>
> What are the things you like about conda over virtualenv?
>
> -Eric
>
>
> On Fri, Feb 13, 2015 at 9:32 AM, pybokeh <pybokeh at gmail.com> wrote:
>
>> Hello List,
>> I know virtualenv gets a lot of mention for making virtual environments,
>> but I recommend conda instead.  Check out http://conda.io/ for more info.
>>
>> - Daniel
>>
>> _______________________________________________
>> CentralOH mailing list
>> CentralOH at python.org
>> https://mail.python.org/mailman/listinfo/centraloh
>>
>>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150213/b3a45ab6/attachment.html>

From eric at intellovations.com  Fri Feb 13 16:52:49 2015
From: eric at intellovations.com (Eric Floehr)
Date: Fri, 13 Feb 2015 10:52:49 -0500
Subject: [CentralOH] conda.io - using conda for virtual environments and
 package management
In-Reply-To: <CAOoMBVioN=ubo9-0yinDOamRLGBbQSKY+dUXJLY8s7UiEP_sZQ@mail.gmail.com>
References: <CAOoMBVgMO9YrgxkY=3PpL8S=Aa62_44ZneLj_QRVO+b+8sxeFQ@mail.gmail.com>
 <CAJzarMOdsNYwQYyhfn3EUWKvjJ5N8ZQO6D8VQUi5sRz+BrXrjw@mail.gmail.com>
 <CAOoMBVioN=ubo9-0yinDOamRLGBbQSKY+dUXJLY8s7UiEP_sZQ@mail.gmail.com>
Message-ID: <CAJzarMPfPPZS0mggNm=OTPJy25iSFPEaUjXNTbo3+jf8xWHQ-w@mail.gmail.com>

Thanks! Having binary packages is a huge benefit, especially for Windows
users. I know that I generally just rely on "with-site-packages" for
virtualenv when I need big packages that need compiled like numpy, scipy,
etc. because it's such a pain to get all the libraries, etc. and verify
correct compilation.

I'll have to check it out...


On Fri, Feb 13, 2015 at 10:20 AM, pybokeh <pybokeh at gmail.com> wrote:

> I think the real advantage is if you are on  Windows or don't want to
> compile packages from source.  Since conda is part of Anaconda
> distribution, there are already many popular pre-compiled binaries readily
> available and Continuum IO the company behind Anaconda usually do a decent
> job of quickly getting the latest version of their packages pushed out.  If
> a package is not available in Anaconda, you can still install it using pip.
>
> Also this is subjective, but I prefer the conda's more user-friendly
> command line arguments over virtualenv's commands.  For example, if you
> want to create an environment for a specific python version, in conda it is
> just python=2.7 or python=3.4 whereas in virtualenv, you have to provide
> the full path to the python interpreter.
>
> This is about all I can think of off the top of my head.  I used to use
> virtualenv, but I guess I got less patient over the years waiting on
> compiling a package from source.
>
> - Daniel
> On Feb 13, 2015 9:38 AM, "Eric Floehr" <eric at intellovations.com> wrote:
>
>> Hi Daniel,
>>
>> What are the things you like about conda over virtualenv?
>>
>> -Eric
>>
>>
>> On Fri, Feb 13, 2015 at 9:32 AM, pybokeh <pybokeh at gmail.com> wrote:
>>
>>> Hello List,
>>> I know virtualenv gets a lot of mention for making virtual environments,
>>> but I recommend conda instead.  Check out http://conda.io/ for more
>>> info.
>>>
>>> - Daniel
>>>
>>> _______________________________________________
>>> CentralOH mailing list
>>> CentralOH at python.org
>>> https://mail.python.org/mailman/listinfo/centraloh
>>>
>>>
>>
>> _______________________________________________
>> CentralOH mailing list
>> CentralOH at python.org
>> https://mail.python.org/mailman/listinfo/centraloh
>>
>>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150213/fb7a8d1a/attachment.html>

From eric at intellovations.com  Mon Feb 16 19:43:24 2015
From: eric at intellovations.com (Eric Floehr)
Date: Mon, 16 Feb 2015 13:43:24 -0500
Subject: [CentralOH] February Monthly Meeting -- Go for Pythonistas
Message-ID: <CAJzarMMi4PfTABOpqe-JeJ6ZpiC83qYVwFLuJq4UDkgV5O9L3A@mail.gmail.com>

Next Monday, February 23, starting at 6pm, we will be having our monthly
meeting.

Please RSVP Here:
http://www.meetup.com/Central-Ohio-Python-Users-Group/events/220561065/

We will be meeting at Pillar, as usual. Pillar will provide food and drink
(thanks Pillar!).

Informal meeting starts at 6pm, with the talk starting at 6:30pm. We will
finish no later than 8:30pm to adjourn to the informal meeting.

Go has sometimes been called the child of C and Python, with built-in
async. This month, Joe Shaw will introduce the Go programming language from
the perspective of a Python programmer. In particular he'll look at PEP-20,
the Zen of Python, and how its principles apply to Go. He'll demonstrate
some of the ways he feels Go embodies the Zen, in some ways better and
other ways not as well.

Jim Prior will also show a few things from his Python grab bag.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150216/b8840d4a/attachment.html>

From eric at intellovations.com  Mon Feb 16 20:05:06 2015
From: eric at intellovations.com (Eric Floehr)
Date: Mon, 16 Feb 2015 14:05:06 -0500
Subject: [CentralOH] COhPy February After-Meeting
Message-ID: <CAJzarMP_ko1vZXq5W4EK1MEZDnHj9avfThFp92-3=bY+ayWciQ@mail.gmail.com>

Please RSVP Here:
http://www.meetup.com/Central-Ohio-Python-Users-Group/events/220561615/

Since parking is good, and there are generally ample tables and good food
and drink we will continue our recent tradition of adjourning to Brazenhead
on Fifth for the monthly meeting after-meeting.

This is an inclusive informal social gathering after the formal meeting and
presentations. It is equally likely topics will be Python or non-Python
related.

Brazenhead has lots of yummy food choices, and many non-alcoholic
beverages. Drinking is neither encouraged nor discouraged, and your choices
will be respected by the group.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150216/82310a22/attachment.html>

From jep200404 at columbus.rr.com  Tue Feb 17 21:03:18 2015
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Tue, 17 Feb 2015 15:03:18 -0500
Subject: [CentralOH] =?utf-8?q?2015-02-13_=E9=81=93=E5=A0=B4_Scribbles_?=
 =?utf-8?b?76SY5pu4L+aDoeaWhz8gR0lTLCBnZW9kamFuZ28sIFBvc3RHSVMsIFRJR0VS?=
 =?utf-8?q?=2C_Proton=2C_tuples=2C_default_functions=2C_LPtHW_ex39?=
Message-ID: <20150217150318.7a192916.jep200404@columbus.rr.com>

To get good answers, consider following the advice in the links below.
http://catb.org/~esr/faqs/smart-questions.html
http://web.archive.org/web/20090627155454/www.greenend.org.uk/rjk/2000/06/14/quoting.html
wp: prefix means Wikipedia

wp:To Serve Man
postgresql
PostGIS
django
geodjango
http://geodjango.org/
wp:GIS
wp:tigger
wp:TIGER
wp:OpenStreetMap

wp:emacs
wp:vim

wp:Proton therapy
wp:Bragg peak
$183M each
    more than a car factory costs

Way to go pybokeh! pybokeh's pandas cheatsheet notebook has been posted to:

    http://nb.bianp.net/sort/views/

https://nbviewer.ipython.org/github/pybokeh/ipython_notebooks/blob/master/pandas/PandasCheatSheet.ipynb

https://github.com/brandon-rhodes/astronomy-notebooks
wp:SPSS
https://mail.python.org/pipermail/centraloh/2013-June/001718.html
wp:PyPy
https://pypi.python.org/pypi/
http://et1337.github.io/shaders/
http://www.pyohio.org/

    O'Reilly offered 2014 attendees free ebooks.

Can default values evaluate a function each time?

    http://nbviewer.ipython.org/url/colug.net/python/dojo/20150213/dojo-20150213-default-arg-evaluation.ipynb

More notebooks: http://www.colug.net/python/dojo/20150213/

https://www.pytennessee.org/schedule/

    http://pytennessee.tumblr.com/post/106799437321/pytn-profiles-eric-floehr-and-stratasan

Way to go Austin!

    Go to tmpnb.org and navigate to the following notebook
    communities / desertpy / pandas-intro-godber-jan-2014
    It looks like he was doing weather.

    The URL I used follows, but it was almost certainly ephemeral.
    https://tmp07.tmpnb.org/user/jVJAA0x8xsDt/tree/communities/desertpy/pandas-intro-godber-jan-2014

very local, very short term weather forecasts http://www.nooly.com/

whocalled.us has an API (not whocalled.me)

written on a napkin with a Sharpie:

    tempered in a crucible of ignorance

Online tutorials such as Zed's Learning Python the Hard Way are helpful,
but have problems. For example: 
https://mail.python.org/pipermail/centraloh/2014-November/002217.html

From jep200404 at columbus.rr.com  Thu Feb 19 23:12:01 2015
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Thu, 19 Feb 2015 17:12:01 -0500
Subject: [CentralOH] Python Lunch
Message-ID: <20150219171201.6bb72dc2.jep200404@columbus.rr.com>

How about Python lunch Monday at Guachos or Mazah? 

Los Guachos Taqueria
1376 Cherry Bottom Rd, Gahanna
los-guachos.com
the gringas are very good!

Mazah
1453 Grandview Ave, Columbus
mazah-eatery.com

Which do you favor? 

What time? Eric chose 11:15 or 11:30 to beat rush last year.

From herrold at owlriver.com  Fri Feb 20 21:01:27 2015
From: herrold at owlriver.com (R P Herrold)
Date: Fri, 20 Feb 2015 15:01:27 -0500 (EST)
Subject: [CentralOH] Python Lunch
In-Reply-To: <20150219171201.6bb72dc2.jep200404@columbus.rr.com>
References: <20150219171201.6bb72dc2.jep200404@columbus.rr.com>
Message-ID: <alpine.LRH.2.03.1502201459220.24644@bjyevire.pbz>

On Thu, 19 Feb 2015, jep200404 at columbus.rr.com wrote:

> How about Python lunch Monday at Guachos or Mazah? 
> 
> Los Guachos Taqueria
> 1376 Cherry Bottom Rd, Gahanna
> los-guachos.com

> the gringas are very good!

there is also an Guachos on Hard Rd, north of Centennial High 
School and Bethel Road, also with yummy gringas, and lime 
wedges and the onion garnish

-- Russ herrold

From jep200404 at columbus.rr.com  Sat Feb 21 17:49:13 2015
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Sat, 21 Feb 2015 11:49:13 -0500
Subject: [CentralOH] =?utf-8?q?2015-02-20_=E9=81=93=E5=A0=B4_Scribbles_?=
 =?utf-8?b?76SY5pu4L+aDoeaWhz8gRXVsZXIgIzEsIFBhc2NhbCdzIHRyaWFuZ2xlLCBt?=
 =?utf-8?q?inmaxsums=2C_toolz=2Ecurried=2Epipe=2C_=5F=2C_Lenovo=2C_termcap?=
 =?utf-8?q?=2C_*_ipsum=2C_sentiment_analysis=2C_jupyter/ipython=2C_ASCII?=
 =?utf-8?q?=2C_ggplot/matplotlib=2C_spyre?=
Message-ID: <20150221114913.7bcefa76.jep200404@columbus.rr.com>

Lenovo
man in the middle
chrome 
ie
certificate
http://arstechnica.com/security/2015/02/lenovo-pcs-ship-with-man-in-the-middle-adware-that-breaks-https-connections/

man xterm
termcap
pypy
sentiment analysis
the quick brown fox jumped over the lazy dog
lorem ipsum
bacon ipsum

mitsubishi has good speech recognition

jupyter is language agnostic version of ipython notebook
http://jupyter.org/
Ipython notebook is such a good idea that it is being broadened to include 
other languages, so the Ipython name is being changed to Jupyter.

http://www.asciimation.co.nz/
hasciicam
bb (demo for aa library)

ggplot smokes matplotlib
%load_ext rpy2.ipython
ggplot
https://github.com/yhat/ggplot/
http://blog.yhathq.com/posts/ggplot-for-python.html

ipython notebook with widgets
r world
http://shiny.rstudio.com/gallery/

https://github.com/adamhajari
https://github.com/adamhajari/spyre

What nice thing in Python was done first in Python?
Did idea for Ipython Notebook come from Wolfram Alpha?
    wolfram alpha http://www.wolframalpha.com/
    No: http://blog.fperez.org/2012/01/ipython-notebook-historical.html

http://colug.net/python/dojo/20150220/

    Pascal's Triangle
    return row for given level
        clear, naive: add slices
        direct calculation

    Project Euler Problem #1        
    Someone else was starting on Project Euler,
    starting with problem #1, 
    so that problem was revisited with 
    direction calculation that avoids iteration.

Given sequence of positive and negative integers,
return slices with greatest and smallest sums.

from toolz.curried import pipe
pipe()

for _ in range(n):  # For when the loop variable is never referenced.

Python

    http://www.coverity.com/press-releases/coverity-finds-python-sets-new-level-of-quality-for-open-source-software/
    security through obscurity
    many eyes make all bugs shallow
    the cathedral and the bazaar

Paul Horn - Inside

From mark at microenh.com  Sun Feb 22 04:10:16 2015
From: mark at microenh.com (Mark Erbaugh)
Date: Sat, 21 Feb 2015 22:10:16 -0500
Subject: [CentralOH] PythonDotNet
Message-ID: <54E94898.8050709@microenh.com>

Greetings,

I am struggling with a hobby project using PythonDotNet.  I have an API 
for an external device written in C# and .NET.  I have the C# code. 
Rather than using IronPython, I am trying to use PythonDotNet with 
CPython 2.7.9. The C# code was not written with any special 
consideration of Python.

The API implements callback functions. I have been able to write several 
of the callback functions in Python and they work. But, now I've come 
across something that I can't figure out, and perhaps it's not supported 
by PythonDotNet. There is a callback routine that passes a C# array of 
shorts.  the C# function signature is

         public delegate void DataReadyEventHandler(Panadapter pan, 
ushort[] data);

No matter how I try to code my Python function, I am getting a runtime 
exception from the PythonRuntime part of PythonDotNet.

Is passing this array possible?

Thanks,
Mark

From williamsonkr at gmail.com  Sun Feb 22 23:53:12 2015
From: williamsonkr at gmail.com (Kyle Williamson)
Date: Sun, 22 Feb 2015 17:53:12 -0500
Subject: [CentralOH] Python and Excel
Message-ID: <CANmk-rw6zQ2kKWR-j3WZbByX-xUKOgCDy4bOfePSLV6PsfeQCQ@mail.gmail.com>

Hello,

    Need some opinions on what everyone is using in Python to work with CSV
files.  Thanks.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150222/270633c3/attachment.html>

From pybokeh at gmail.com  Mon Feb 23 00:01:10 2015
From: pybokeh at gmail.com (pybokeh)
Date: Sun, 22 Feb 2015 18:01:10 -0500
Subject: [CentralOH] Python and Excel
In-Reply-To: <CANmk-rw6zQ2kKWR-j3WZbByX-xUKOgCDy4bOfePSLV6PsfeQCQ@mail.gmail.com>
References: <CANmk-rw6zQ2kKWR-j3WZbByX-xUKOgCDy4bOfePSLV6PsfeQCQ@mail.gmail.com>
Message-ID: <CAOoMBVi8Mqr=7XROz-q+cEJ3Wt7J=Q1m21wwHKJnMji946iRqA@mail.gmail.com>

If the csv file is large and won't fit into memory, you can use the csv
module and 'lazily' read in the data from the csv file using a generator.
Here's an article that covers that:
http://districtdatalabs.silvrback.com/simple-csv-data-wrangling-with-python

Otherwise, I would use the read_csv() method from the pandas library.

- Daniel
On Feb 22, 2015 5:53 PM, "Kyle Williamson" <williamsonkr at gmail.com> wrote:

> Hello,
>
>     Need some opinions on what everyone is using in Python to work with
> CSV files.  Thanks.
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150222/28e9dc1e/attachment.html>

From andrewcfitzgerald at gmail.com  Mon Feb 23 00:01:14 2015
From: andrewcfitzgerald at gmail.com (Andrew Fitzgerald)
Date: Sun, 22 Feb 2015 18:01:14 -0500
Subject: [CentralOH] Python and Excel
In-Reply-To: <CANmk-rw6zQ2kKWR-j3WZbByX-xUKOgCDy4bOfePSLV6PsfeQCQ@mail.gmail.com>
References: <CANmk-rw6zQ2kKWR-j3WZbByX-xUKOgCDy4bOfePSLV6PsfeQCQ@mail.gmail.com>
Message-ID: <CACkx_dDzTTHZPoW5r-Bs6dDgUOVYs8Q=AiAdkQp2+oR-kgkR5g@mail.gmail.com>

Most of the time I end up using the standard library csv module.
https://docs.python.org/2/library/csv.html

Pandas is also potentially useful depending on what you're trying to do.
http://pandas.pydata.org/pandas-docs/dev/io.html



On Sun, Feb 22, 2015 at 5:53 PM, Kyle Williamson <williamsonkr at gmail.com>
wrote:

> Hello,
>
>     Need some opinions on what everyone is using in Python to work with
> CSV files.  Thanks.
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150222/dd26e2da/attachment.html>

From jep200404 at columbus.rr.com  Mon Feb 23 00:31:44 2015
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Sun, 22 Feb 2015 18:31:44 -0500
Subject: [CentralOH] Python[, CSV,] and Excel
In-Reply-To: <CANmk-rw6zQ2kKWR-j3WZbByX-xUKOgCDy4bOfePSLV6PsfeQCQ@mail.gmail.com>
References: <CANmk-rw6zQ2kKWR-j3WZbByX-xUKOgCDy4bOfePSLV6PsfeQCQ@mail.gmail.com>
Message-ID: <20150222183144.55152a44.jep200404@columbus.rr.com>

On Sun, 22 Feb 2015 17:53:12 -0500, Kyle Williamson <williamsonkr at gmail.com> wrote:

> Need some opinions on what everyone is using in Python to work 
> with CSV files.

We use the csv module. 

One can often easily find the dox with useful examples by
searching for python and whatever it is that you are messing 
with. For example, 

    https://duckduckgo.com/html/?q=python+csv
    https://duckduckgo.com/html/?q=python+csv+excel

quickly lead to the relevant dox.

Context managers are nifty. Use them.
Examples of such are in the dox.

You mentioned Excel but not CSV in the Subject 
and CSV but not Excel in the body of your letter.
You might be interested in the excel and excel_tab dialects.

From brian.costlow at gmail.com  Mon Feb 23 00:49:17 2015
From: brian.costlow at gmail.com (Brian Costlow)
Date: Sun, 22 Feb 2015 18:49:17 -0500
Subject: [CentralOH] Python and Excel
In-Reply-To: <CACkx_dDzTTHZPoW5r-Bs6dDgUOVYs8Q=AiAdkQp2+oR-kgkR5g@mail.gmail.com>
References: <CANmk-rw6zQ2kKWR-j3WZbByX-xUKOgCDy4bOfePSLV6PsfeQCQ@mail.gmail.com>
 <CACkx_dDzTTHZPoW5r-Bs6dDgUOVYs8Q=AiAdkQp2+oR-kgkR5g@mail.gmail.com>
Message-ID: <CACLJ_dHodq5EfFYpttuGP79Ery6o0CEXnv6f0ZdRz=bHeRB8TQ@mail.gmail.com>

You mentioned excel in your subject.

I've used this to create actual excel files after manipulating tab data:
https://github.com/kennethreitz/tablib

But for some relatively small datasets. So I don't know how it holds up for
big stuff.

On Sun, Feb 22, 2015 at 6:01 PM, Andrew Fitzgerald <
andrewcfitzgerald at gmail.com> wrote:

> Most of the time I end up using the standard library csv module.
> https://docs.python.org/2/library/csv.html
>
> Pandas is also potentially useful depending on what you're trying to do.
> http://pandas.pydata.org/pandas-docs/dev/io.html
>
>
>
> On Sun, Feb 22, 2015 at 5:53 PM, Kyle Williamson <williamsonkr at gmail.com>
> wrote:
>
>> Hello,
>>
>>     Need some opinions on what everyone is using in Python to work with
>> CSV files.  Thanks.
>>
>> _______________________________________________
>> CentralOH mailing list
>> CentralOH at python.org
>> https://mail.python.org/mailman/listinfo/centraloh
>>
>>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150222/db44ef04/attachment.html>

From winningham at gmail.com  Mon Feb 23 01:56:14 2015
From: winningham at gmail.com (Thomas Winningham)
Date: Sun, 22 Feb 2015 19:56:14 -0500
Subject: [CentralOH] PythonDotNet
In-Reply-To: <54E94898.8050709@microenh.com>
References: <54E94898.8050709@microenh.com>
Message-ID: <CAJShLf_CgxBfEt39ANxGTcmhywAGWYXgU_DpvwMxdgKiw74pSg@mail.gmail.com>

I had been thinking about this, and while I haven't messed with Python on
.NET, I have messed with C# some, as well as other Python on top of another
language type arrangements.

There must be either one of two things you can do, but the details of which
you may be on your own to investigate (sorry):

1. The Python.NET, being dynamically typed, must have some sort of
functions to support the static (and more specific) types of the .NET
system. This may be something that allows you to specifically create a C#
compatible array of unsigned shorts like that second parameter of the
function requires. I would imagine a study of the documentation for
Python.NET may well reveal some kind of capability like this as a language
support library or something similar. I know with say, Jython, it is called
Java Interop, same with Clojure on the JVM.

2. You could approach this the other way, and write some C# to wrap this
function in a function that does work with Python the way you want or
however you can get it to work, then in this new C# function, coerce the
types passed in to be an array of unsigned shorts, and pass that to the
original function.

Best of luck, and let us know if you find anything interesting.

Thomas


On Sat, Feb 21, 2015 at 10:10 PM, Mark Erbaugh <mark at microenh.com> wrote:

> Greetings,
>
> I am struggling with a hobby project using PythonDotNet.  I have an API
> for an external device written in C# and .NET.  I have the C# code. Rather
> than using IronPython, I am trying to use PythonDotNet with CPython 2.7.9.
> The C# code was not written with any special consideration of Python.
>
> The API implements callback functions. I have been able to write several
> of the callback functions in Python and they work. But, now I've come
> across something that I can't figure out, and perhaps it's not supported by
> PythonDotNet. There is a callback routine that passes a C# array of
> shorts.  the C# function signature is
>
>         public delegate void DataReadyEventHandler(Panadapter pan,
> ushort[] data);
>
> No matter how I try to code my Python function, I am getting a runtime
> exception from the PythonRuntime part of PythonDotNet.
>
> Is passing this array possible?
>
> Thanks,
> Mark
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150222/8b1bc780/attachment-0001.html>

From brywilharris at gmail.com  Mon Feb 23 15:03:53 2015
From: brywilharris at gmail.com (Bryan Harris)
Date: Mon, 23 Feb 2015 09:03:53 -0500
Subject: [CentralOH] Python and Excel
In-Reply-To: <CACLJ_dHodq5EfFYpttuGP79Ery6o0CEXnv6f0ZdRz=bHeRB8TQ@mail.gmail.com>
References: <CANmk-rw6zQ2kKWR-j3WZbByX-xUKOgCDy4bOfePSLV6PsfeQCQ@mail.gmail.com>
 <CACkx_dDzTTHZPoW5r-Bs6dDgUOVYs8Q=AiAdkQp2+oR-kgkR5g@mail.gmail.com>
 <CACLJ_dHodq5EfFYpttuGP79Ery6o0CEXnv6f0ZdRz=bHeRB8TQ@mail.gmail.com>
Message-ID: <CADYFESHMiBrW9QfuNL5nFt0pSxeVGnfQWbt_A4N-PVb+ni3z-g@mail.gmail.com>

The python CSV module works for large files.

Bryan Harris, PE
Research Engineer
Structures and Materials Evaluation Group
University of Dayton Research Institute
bryan.harris at udri.udayton.edu
http://www.udri.udayton.edu/
937-229-5561
On Feb 22, 2015 6:49 PM, "Brian Costlow" <brian.costlow at gmail.com> wrote:

> You mentioned excel in your subject.
>
> I've used this to create actual excel files after manipulating tab data:
> https://github.com/kennethreitz/tablib
>
> But for some relatively small datasets. So I don't know how it holds up
> for big stuff.
>
> On Sun, Feb 22, 2015 at 6:01 PM, Andrew Fitzgerald <
> andrewcfitzgerald at gmail.com> wrote:
>
>> Most of the time I end up using the standard library csv module.
>> https://docs.python.org/2/library/csv.html
>>
>> Pandas is also potentially useful depending on what you're trying to do.
>> http://pandas.pydata.org/pandas-docs/dev/io.html
>>
>>
>>
>> On Sun, Feb 22, 2015 at 5:53 PM, Kyle Williamson <williamsonkr at gmail.com>
>> wrote:
>>
>>> Hello,
>>>
>>>     Need some opinions on what everyone is using in Python to work with
>>> CSV files.  Thanks.
>>>
>>> _______________________________________________
>>> CentralOH mailing list
>>> CentralOH at python.org
>>> https://mail.python.org/mailman/listinfo/centraloh
>>>
>>>
>>
>> _______________________________________________
>> CentralOH mailing list
>> CentralOH at python.org
>> https://mail.python.org/mailman/listinfo/centraloh
>>
>>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150223/767320a6/attachment.html>

From jep200404 at columbus.rr.com  Mon Feb 23 16:04:09 2015
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Mon, 23 Feb 2015 10:04:09 -0500
Subject: [CentralOH] Python Lunch: Nevermind
In-Reply-To: <20150219171201.6bb72dc2.jep200404@columbus.rr.com>
References: <20150219171201.6bb72dc2.jep200404@columbus.rr.com>
Message-ID: <20150223100409.6b6aebf1.jep200404@columbus.rr.com>

On Thu, 19 Feb 2015 17:12:01 -0500, jep200404 at columbus.rr.com wrote:

> How about Python lunch Monday at Guachos or Mazah? 

It's 10am and I've not heard interest, so nevermind.

From bgohar at osc.edu  Mon Feb 23 20:33:09 2015
From: bgohar at osc.edu (Basil Mohamed Gohar)
Date: Mon, 23 Feb 2015 14:33:09 -0500
Subject: [CentralOH] February Monthly Meeting -- Go for Pythonistas
In-Reply-To: <CAJzarMMi4PfTABOpqe-JeJ6ZpiC83qYVwFLuJq4UDkgV5O9L3A@mail.gmail.com>
References: <CAJzarMMi4PfTABOpqe-JeJ6ZpiC83qYVwFLuJq4UDkgV5O9L3A@mail.gmail.com>
Message-ID: <54EB8075.3050108@osc.edu>

I regretfully cannot attend tonight's meeting, most likely, but I hope 
it goes well and I look forward to seeing you all again at a future meeting.
------------------------------------------------------------------------
Basil Mohamed Gohar, Web & Interface Applications Manager
Ohio Supercomputer Center
An Ohio Technology Consortium (OH-TECH) Member
1224 Kinnear Road
Columbus, OH 43212
Phone: (614) 688-0979
email: bgohar at osc.edu

Learn more about the Ohio Supercomputer Center at https://www.osc.edu.
On 2/16/15 1:43 PM, Eric Floehr wrote:
>
> Next Monday, February 23, starting at 6pm, we will be having our 
> monthly meeting.
>
> Please RSVP Here: 
> http://www.meetup.com/Central-Ohio-Python-Users-Group/events/220561065/
>
> We will be meeting at Pillar, as usual. Pillar will provide food and 
> drink (thanks Pillar!).
>
> Informal meeting starts at 6pm, with the talk starting at 6:30pm. We 
> will finish no later than 8:30pm to adjourn to the informal meeting.
>
> Go has sometimes been called the child of C and Python, with built-in 
> async. This month, Joe Shaw will introduce the Go programming language 
> from the perspective of a Python programmer. In particular he'll look 
> at PEP-20, the Zen of Python, and how its principles apply to Go. 
> He'll demonstrate some of the ways he feels Go embodies the Zen, in 
> some ways better and other ways not as well.
>
> Jim Prior will also show a few things from his Python grab bag.
>
>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150223/9f67b4ed/attachment.html>

From winningham at gmail.com  Mon Feb 23 20:45:56 2015
From: winningham at gmail.com (Thomas Winningham)
Date: Mon, 23 Feb 2015 14:45:56 -0500
Subject: [CentralOH] PythonDotNet
In-Reply-To: <CAJShLf_CgxBfEt39ANxGTcmhywAGWYXgU_DpvwMxdgKiw74pSg@mail.gmail.com>
References: <54E94898.8050709@microenh.com>
 <CAJShLf_CgxBfEt39ANxGTcmhywAGWYXgU_DpvwMxdgKiw74pSg@mail.gmail.com>
Message-ID: <CAJShLf_kUKTWnBt9a3iMepku01yvJhuM17=4oeD4kzBfw-RmiA@mail.gmail.com>

So I re-read your email, and my reply, and noticed I missed a subtlety,
you're trying to get a Python.NET callback to work with a .NET function.
This may not work unless the Python.NET allows you to override or somehow
annotate a function's accepted types. The "method signature" in Java
parlance means that whatever you write in Python is not going to appear
like a valid callback method, as the parameters may be of a different type
than what the callback allows. There *ought* to be a way to make a Python
function that appears to the .NET CLR as having this method signature, but
I'm not sure.

I guess the same advice applies, but if what I described above doesn't
exist, you may be in the C# world more if you can't find a way to
explicitly define the Python function's parameter types. Essentially, write
C# that can call your Python function, but that C# has to require
parameters with the types aligned with the original callback.

On Sun, Feb 22, 2015 at 7:56 PM, Thomas Winningham <winningham at gmail.com>
wrote:

> I had been thinking about this, and while I haven't messed with Python on
> .NET, I have messed with C# some, as well as other Python on top of another
> language type arrangements.
>
> There must be either one of two things you can do, but the details of
> which you may be on your own to investigate (sorry):
>
> 1. The Python.NET, being dynamically typed, must have some sort of
> functions to support the static (and more specific) types of the .NET
> system. This may be something that allows you to specifically create a C#
> compatible array of unsigned shorts like that second parameter of the
> function requires. I would imagine a study of the documentation for
> Python.NET may well reveal some kind of capability like this as a language
> support library or something similar. I know with say, Jython, it is called
> Java Interop, same with Clojure on the JVM.
>
> 2. You could approach this the other way, and write some C# to wrap this
> function in a function that does work with Python the way you want or
> however you can get it to work, then in this new C# function, coerce the
> types passed in to be an array of unsigned shorts, and pass that to the
> original function.
>
> Best of luck, and let us know if you find anything interesting.
>
> Thomas
>
>
> On Sat, Feb 21, 2015 at 10:10 PM, Mark Erbaugh <mark at microenh.com> wrote:
>
>> Greetings,
>>
>> I am struggling with a hobby project using PythonDotNet.  I have an API
>> for an external device written in C# and .NET.  I have the C# code. Rather
>> than using IronPython, I am trying to use PythonDotNet with CPython 2.7.9.
>> The C# code was not written with any special consideration of Python.
>>
>> The API implements callback functions. I have been able to write several
>> of the callback functions in Python and they work. But, now I've come
>> across something that I can't figure out, and perhaps it's not supported by
>> PythonDotNet. There is a callback routine that passes a C# array of
>> shorts.  the C# function signature is
>>
>>         public delegate void DataReadyEventHandler(Panadapter pan,
>> ushort[] data);
>>
>> No matter how I try to code my Python function, I am getting a runtime
>> exception from the PythonRuntime part of PythonDotNet.
>>
>> Is passing this array possible?
>>
>> Thanks,
>> Mark
>> _______________________________________________
>> CentralOH mailing list
>> CentralOH at python.org
>> https://mail.python.org/mailman/listinfo/centraloh
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150223/5ab86d1f/attachment-0001.html>

From brywilharris at gmail.com  Mon Feb 23 23:05:52 2015
From: brywilharris at gmail.com (Bryan Harris)
Date: Mon, 23 Feb 2015 17:05:52 -0500
Subject: [CentralOH] Job opportunity at Cincinnati Children's Hospital
Message-ID: <CADYFESERaeaWTZ0YnYUfJbGpdUiaw2eCf8oNjGt_JJnnVwFbjA@mail.gmail.com>

Hey all,

I had a head hunter contact me looking for a programmer for a job with
Cincinnati Children's.  Is it appropriate to post job openings to this list?

Bryan
On Feb 23, 2015 2:46 PM, "Thomas Winningham" <winningham at gmail.com> wrote:

> So I re-read your email, and my reply, and noticed I missed a subtlety,
> you're trying to get a Python.NET callback to work with a .NET function.
> This may not work unless the Python.NET allows you to override or somehow
> annotate a function's accepted types. The "method signature" in Java
> parlance means that whatever you write in Python is not going to appear
> like a valid callback method, as the parameters may be of a different type
> than what the callback allows. There *ought* to be a way to make a Python
> function that appears to the .NET CLR as having this method signature, but
> I'm not sure.
>
> I guess the same advice applies, but if what I described above doesn't
> exist, you may be in the C# world more if you can't find a way to
> explicitly define the Python function's parameter types. Essentially, write
> C# that can call your Python function, but that C# has to require
> parameters with the types aligned with the original callback.
>
> On Sun, Feb 22, 2015 at 7:56 PM, Thomas Winningham <winningham at gmail.com>
> wrote:
>
>> I had been thinking about this, and while I haven't messed with Python on
>> .NET, I have messed with C# some, as well as other Python on top of another
>> language type arrangements.
>>
>> There must be either one of two things you can do, but the details of
>> which you may be on your own to investigate (sorry):
>>
>> 1. The Python.NET, being dynamically typed, must have some sort of
>> functions to support the static (and more specific) types of the .NET
>> system. This may be something that allows you to specifically create a C#
>> compatible array of unsigned shorts like that second parameter of the
>> function requires. I would imagine a study of the documentation for
>> Python.NET may well reveal some kind of capability like this as a language
>> support library or something similar. I know with say, Jython, it is called
>> Java Interop, same with Clojure on the JVM.
>>
>> 2. You could approach this the other way, and write some C# to wrap this
>> function in a function that does work with Python the way you want or
>> however you can get it to work, then in this new C# function, coerce the
>> types passed in to be an array of unsigned shorts, and pass that to the
>> original function.
>>
>> Best of luck, and let us know if you find anything interesting.
>>
>> Thomas
>>
>>
>> On Sat, Feb 21, 2015 at 10:10 PM, Mark Erbaugh <mark at microenh.com> wrote:
>>
>>> Greetings,
>>>
>>> I am struggling with a hobby project using PythonDotNet.  I have an API
>>> for an external device written in C# and .NET.  I have the C# code. Rather
>>> than using IronPython, I am trying to use PythonDotNet with CPython 2.7.9.
>>> The C# code was not written with any special consideration of Python.
>>>
>>> The API implements callback functions. I have been able to write several
>>> of the callback functions in Python and they work. But, now I've come
>>> across something that I can't figure out, and perhaps it's not supported by
>>> PythonDotNet. There is a callback routine that passes a C# array of
>>> shorts.  the C# function signature is
>>>
>>>         public delegate void DataReadyEventHandler(Panadapter pan,
>>> ushort[] data);
>>>
>>> No matter how I try to code my Python function, I am getting a runtime
>>> exception from the PythonRuntime part of PythonDotNet.
>>>
>>> Is passing this array possible?
>>>
>>> Thanks,
>>> Mark
>>> _______________________________________________
>>> CentralOH mailing list
>>> CentralOH at python.org
>>> https://mail.python.org/mailman/listinfo/centraloh
>>>
>>
>>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150223/75078faf/attachment.html>

From joe at joeshaw.org  Tue Feb 24 15:23:30 2015
From: joe at joeshaw.org (Joe Shaw)
Date: Tue, 24 Feb 2015 09:23:30 -0500
Subject: [CentralOH] February Monthly Meeting -- Go for Pythonistas
In-Reply-To: <CAJzarMMi4PfTABOpqe-JeJ6ZpiC83qYVwFLuJq4UDkgV5O9L3A@mail.gmail.com>
References: <CAJzarMMi4PfTABOpqe-JeJ6ZpiC83qYVwFLuJq4UDkgV5O9L3A@mail.gmail.com>
Message-ID: <CAOxvq7zmrDPCfjRRTDZBg1s-ZTqt24T7J0nW0NRifiswrqu1Lg@mail.gmail.com>

Hi,

Thanks again for allowing me to talk last night about Go.  My slides are
online here:

https://go-talks.appspot.com/github.com/joeshaw/talks/cohpy/zen.slide#1

and the source is available here:

https://github.com/joeshaw/talks

Let me know if you have any questions.

Joe

On Mon, Feb 16, 2015 at 1:43 PM, Eric Floehr <eric at intellovations.com>
wrote:

> Next Monday, February 23, starting at 6pm, we will be having our monthly
> meeting.
>
> Please RSVP Here:
> http://www.meetup.com/Central-Ohio-Python-Users-Group/events/220561065/
>
> We will be meeting at Pillar, as usual. Pillar will provide food and drink
> (thanks Pillar!).
>
> Informal meeting starts at 6pm, with the talk starting at 6:30pm. We will
> finish no later than 8:30pm to adjourn to the informal meeting.
>
> Go has sometimes been called the child of C and Python, with built-in
> async. This month, Joe Shaw will introduce the Go programming language from
> the perspective of a Python programmer. In particular he'll look at PEP-20,
> the Zen of Python, and how its principles apply to Go. He'll demonstrate
> some of the ways he feels Go embodies the Zen, in some ways better and
> other ways not as well.
>
> Jim Prior will also show a few things from his Python grab bag.
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150224/e62c3fb9/attachment.html>

From eric at intellovations.com  Tue Feb 24 15:29:43 2015
From: eric at intellovations.com (Eric Floehr)
Date: Tue, 24 Feb 2015 09:29:43 -0500
Subject: [CentralOH] February Monthly Meeting -- Go for Pythonistas
In-Reply-To: <CAOxvq7zmrDPCfjRRTDZBg1s-ZTqt24T7J0nW0NRifiswrqu1Lg@mail.gmail.com>
References: <CAJzarMMi4PfTABOpqe-JeJ6ZpiC83qYVwFLuJq4UDkgV5O9L3A@mail.gmail.com>
 <CAOxvq7zmrDPCfjRRTDZBg1s-ZTqt24T7J0nW0NRifiswrqu1Lg@mail.gmail.com>
Message-ID: <CAJzarMOvtho_qh4PebfyS6ex1hm8y_oZBhyahjCEYe9Qgdaong@mail.gmail.com>

Thanks for your talk last night, Joe! I learned a lot about Go and also
made me think about Python in a different way.

Cheers,
Eric


On Tue, Feb 24, 2015 at 9:23 AM, Joe Shaw <joe at joeshaw.org> wrote:

> Hi,
>
> Thanks again for allowing me to talk last night about Go.  My slides are
> online here:
>
> https://go-talks.appspot.com/github.com/joeshaw/talks/cohpy/zen.slide#1
>
> and the source is available here:
>
> https://github.com/joeshaw/talks
>
> Let me know if you have any questions.
>
> Joe
>
> On Mon, Feb 16, 2015 at 1:43 PM, Eric Floehr <eric at intellovations.com>
> wrote:
>
>> Next Monday, February 23, starting at 6pm, we will be having our monthly
>> meeting.
>>
>> Please RSVP Here:
>> http://www.meetup.com/Central-Ohio-Python-Users-Group/events/220561065/
>>
>> We will be meeting at Pillar, as usual. Pillar will provide food and
>> drink (thanks Pillar!).
>>
>> Informal meeting starts at 6pm, with the talk starting at 6:30pm. We will
>> finish no later than 8:30pm to adjourn to the informal meeting.
>>
>> Go has sometimes been called the child of C and Python, with built-in
>> async. This month, Joe Shaw will introduce the Go programming language from
>> the perspective of a Python programmer. In particular he'll look at PEP-20,
>> the Zen of Python, and how its principles apply to Go. He'll demonstrate
>> some of the ways he feels Go embodies the Zen, in some ways better and
>> other ways not as well.
>>
>> Jim Prior will also show a few things from his Python grab bag.
>>
>> _______________________________________________
>> CentralOH mailing list
>> CentralOH at python.org
>> https://mail.python.org/mailman/listinfo/centraloh
>>
>>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150224/8d494129/attachment.html>

From eric at intellovations.com  Tue Feb 24 16:34:28 2015
From: eric at intellovations.com (Eric Floehr)
Date: Tue, 24 Feb 2015 10:34:28 -0500
Subject: [CentralOH] Goroutines in Python
Message-ID: <CAJzarMOMqt0urjwa-ZOCVQ5wMTJqRShBgAUdK1p5uMi3O-wnFA@mail.gmail.com>

All,

Go is a pretty cool language, and Joe did a great job introducing it last
night. By all means, play with it, try it, etc. It may work better than
Python for your needs.

One of the things that intrigued me the most was goroutines. I've been
playing with Python 3 on and off, and one of the biggest new features of
Python 3.4 is the introduction of asynchronous IO and light-weight
coroutines (goroutines are mostly like coroutines).

If you want to play around with Python's version of these Go topics, there
are a number of great resources, including Brian Costlow's async talk at
the last PyOhio (links in the gist below).

I dug around for some examples of fetching URLs using the new asyncio, as I
currently use heavy-weight threads to pull about 17,000 unique URLs every
day, and am looking to improve that (there are plans for 10x the number of
URLs).  So Joe's URL fetching example was of particular interest.

So I took a quick stab at recreating it. I cheated a little by using a
third-party library that has native support for asyncio (aiohttp), but with
a little more work, requests can be adapted for asyncio. If you don't have
a binary aiohttp library available for your system, it requires gcc and
python-dev (source) to build.

I also added optional throttling via a semaphore. You can set how many HTTP
requests you want to issue at any one time. You'll have to uncomment some
code for that... as it runs, it fires them all off at once.

Anyway, here is the gist with the Go version and the Python version, along
with links to some good docs and videos on ayncio in Python.

https://gist.github.com/efloehr/d3626762835aa2de83b8

Cheers,
Eric
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150224/2961aab6/attachment.html>

From jep200404 at columbus.rr.com  Tue Feb 24 18:53:59 2015
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Tue, 24 Feb 2015 12:53:59 -0500
Subject: [CentralOH] =?utf-8?q?2015-02-23_=E6=9C=83=E8=AD=B0_Scribbles_?=
 =?utf-8?b?76SY5pu4L+aDoeaWhz86IE1yLiBSb29uZXksIEFwcmlsIEZvb2wsIERhdGFi?=
 =?utf-8?q?ase_Migration=3A_SQLAlchemy/Alembic_versus_Django_ORM=2C_go=2C_?=
 =?utf-8?q?memoization=2C_closure=2C_dict=2Eget=28=29=2C_dict=2Esetdefault?=
 =?utf-8?q?=28=29=2C_well_tempered_Lars_on_Mars=2C_C++_in_iPython_notebook?=
Message-ID: <20150224125359.070a46d3.jep200404@columbus.rr.com>

Thanks again to Pillar with Raymond Chandler for hosting us.
Pillar is a very generous host again. The Thai pizza was very good.

We look forward to seeing posted:
    technique for doing C++ in Ipython notebook
    Joe Shaw's slides
    Jim Reed's slides
    video of K Lars Lohn's PyTn presentation

        https://www.pytennessee.org/schedule/presentation/66/

wp: prefix means Wikipedia
To get good answers, consider following the advice in the links below.

    http://catb.org/~esr/faqs/smart-questions.html
    http://web.archive.org/web/20090627155454/www.greenend.org.uk/rjk/2000/06/14/quoting.html

What is the name of the album released in the 1970s 
that had well tempered stuff done on a synthesizer?
Was it done by somebody other than Glenn Gould?

were in Pillar's "Launchpad" (west)
native resolution of the right projector seems to be 1920x1080
in spite of label on wall that says "MAX RES 1680X1050".
The label on the HDMI 2 button is inverted top for bottom.
Need to take key cap off, and flip the label over.
On the control panel, hit the left or right button to select which projector
one wants to select an input for, then hit input button for which input one want to connect
to the selected projector. We had much less difficulty with these projectors
than in the Forge.

    wifi worked fine automatically

whacking video modes messed up xfce

Lars' presentation at PyTN
    somebody showed a video of it on their phone

jim prior reviewed memoization
    
    argument packing and unpacking
    memoization is a technique used to make a function faster by 
    remembering and returning previously calculated results, 
    so that which remembers calculated return values of a functioninvolved a function that 

    wp:Closure (computer programming)
    Closures are a wierd thing which can make your
    head wobble the first time one encounters them.
    Watching Brandon Rhodes' video "Names, Objects, and Plummeting From The
    Cliff" will help one understand persistance with closures.
    
        http://pyvideo.org/video/542/

    Links for the Ipython notebook used in the presentation are in the 
    scribbles previously posted to the list and archived at the following URL.
    https://mail.python.org/pipermail/centraloh/2015-January/002312.html

    Should have spent less time on .items() and argument unpacking.

    After the presentation, someone suggested using the .get() method of
    dictionaries, to avoid the 'if x not in results:' test. Unfortunately, the
    .get() method does not change the dictionary, so we would have to
    explicitly save the result, so helper would be defined as:

        def helper(x):
            results[x] = results.get(x, f(x))
            return results[x]

    That 'results[x] = ' is a bit ugly. Of course, someone really meant to
    suggest the .setdefault() method, which yields elegant code:

        def helper(x):
            return results.setdefault(x, f(x))

    Unfortunately, a problem with both of them is that f(x) is _always_ called,
    defeating the purpose of memoization.

    The new notebook showing how bad the .get() and .setdefault() methods were
    will be at colug.net/python/cohpy/20150223/

    need to put on my github account
    Eric wants to put that content on a cohpy account at github.

joe shaw

    Gave presentation on Go language, comparing its virtues with those of
    The Zen of Python PEP #20 https://www.python.org/dev/peps/pep-0020/
    Using the Zen of Python was a good template for the presentation.

    Functions can return arbitrary number of values, similar to python.

    We look forward to Joe posting his slides.

jim reed

    Mars lander

    COD3: C under very strict rules 2.5M lines of code for Mars thing
    had very low defect rate, 5 total defects or was it 5 defects per million
    lines? The C code was tested with 25 k lines of Python code?

    Python has unusually low defect rate in python itself.
    http://www.coverity.com/press-releases/coverity-finds-python-sets-new-level-of-quality-for-open-source-software/

    We look forward to Jim posting his slides also.

question: migration ability: sqlalchemy versus django ORM

    Alembic is the thing for migration for SQLAlchemy,
    but don't know enough to compare with Django ORM's migration support.
    (People know one or the other but not both.)

April Fool's paraphased and misinterpreted

    Three high school students, Aaron, Bob, and Chuck who were into theatre
    decided to put on an April Fool's day prank in the lunch room near the area
    where they usually ate with their friends. Aaron and Bob made a list of
    plausible things that would provoke each other and practiced an escalating
    confrontation that would lead to a fight between them. Chuck's role was to
    keep everyone else (who did not know the confrontation was all fake) away
    from Aaron and Bob so the confrontation could go on. On April 1st, the mock
    confrontation was staged. At one point Bob slammed Aaron against a door
    which made a big sound down the hall. Then the vice-principle comes in to
    see Aaron slumped down with Bob standing nearby. Chuck volunteers "Bob hit
    Aaron". The veep chastises Bob, noting that they have talked about this
    before, telling Aaron and Bob to come with him. On the way to his office,
    he stops at the intersection of two halls. The veep and Bob have an
    escalating conversation. Several times Bob tries to tell the veep that the
    veep does not understand the situation, but the veep keeps cutting him off
    until the veep says to Bob "No, _you_ don't understand the situation. April
    Fool's.". Aaron and Chuck had talked to the veep beforehand. The veep was
    in on it but not Bob. Bob is stunned at the turn of events, curses all
    those involved and walked away very peeved. Bob stayed peeved for a long
    time.

What could Mr. Rooney have learned from that?

From james at atlantixeng.com  Tue Feb 24 19:00:29 2015
From: james at atlantixeng.com (James Bonanno)
Date: Tue, 24 Feb 2015 13:00:29 -0500
Subject: [CentralOH] Additional Go Language Influences
In-Reply-To: <mailman.115574.1424800447.18129.centraloh@python.org>
References: <mailman.115574.1424800447.18129.centraloh@python.org>
Message-ID: <54ECBC3D.1020904@atlantixeng.com>

Looking over the Go programming language, it seems to me to have similar 
syntax to Ada and VHDL languages, and the general paradigms of 
concurrency are emulated in memory versus truly parallel processes. What 
I like about it is the light overhead of the concurrency. This is the 
first software language that I've seen come close to this type of 
methodology. I know the presenter mentioned Pascal as an influence, but 
I would also mention these other languages. Will Python develop a 
lightweight concurrency model? --James

From joe at joeshaw.org  Tue Feb 24 19:53:36 2015
From: joe at joeshaw.org (Joe Shaw)
Date: Tue, 24 Feb 2015 13:53:36 -0500
Subject: [CentralOH] Additional Go Language Influences
In-Reply-To: <54ECBC3D.1020904@atlantixeng.com>
References: <mailman.115574.1424800447.18129.centraloh@python.org>
 <54ECBC3D.1020904@atlantixeng.com>
Message-ID: <CAOxvq7x7h3iDhMibgyzX91vbO-XV+vs_B8nMBD2tw0PxAP_F8A@mail.gmail.com>

Hi,

On Tue, Feb 24, 2015 at 1:00 PM, James Bonanno <james at atlantixeng.com>
wrote:

> Looking over the Go programming language, it seems to me to have similar
> syntax to Ada and VHDL languages, and the general paradigms of concurrency
> are emulated in memory versus truly parallel processes. What I like about
> it is the light overhead of the concurrency. This is the first software
> language that I've seen come close to this type of methodology. I know the
> presenter mentioned Pascal as an influence, but I would also mention these
> other languages.


Thanks for the info.  I am not too familiar with Ada or VHDL.  The basis of
Go's concurrency is a series of papers on Communicating Sequential
Processes (CSP) from 1978.
http://en.wikipedia.org/wiki/Communicating_sequential_processes

This is also where Erlang gets its concurrency model from.  As you mention,
though, there is a pretty big difference in that Go's are all within a
single process.  There are both advantages and disadvantages to this, and
the lightness of creating goroutines is one of them.

Other than C, the most direct ancestor of Go (and its source of concurrency
syntax) comes from a small language called Newsqueak (
http://en.wikipedia.org/wiki/Newsqueak) that was also created by Rob Pike.
Its influence comes largely from CSP and Smalltalk.


> Will Python develop a lightweight concurrency model?


Python has some external projects which have introduced the idea of "green
threads", such as greenlet and gevent.  However, I think Go's greatest
strength is that the concurrency is baked in at a very fundamental level in
the language and runtime.  Gevent for instance does some pretty scary
monkeypatching of various low-level functions in places like the socket and
os modules to achieve concurrency.

I think to get the kind of concurrency Go enjoys would require a Python
4-like re-breaking of the language syntax, which I think would be a tough
sell. Maybe it could be done incrementally, I'm not sure.

One of the things I like best about Go is that goroutines allow you to
write code in a very linear, sequential, non-concurrent fashion and add
asynchronicity later.  If you look at my first example from the talk, the
concurrent URL fetcher:

     https://github.com/joeshaw/talks/blob/master/cohpy/fetch.go

notice that the fetch() function does not involve concurrency at all.  It
is how we use and compose that function later inside main() that makes the
concurrency work.  It's a best practice in Go that APIs you write should
not expose goroutines or channels but instead act synchronously.  The
consumers of your API should have the freedom to make them asynchronous by
running them in a goroutine.

While I think the asyncio stuff in Python is really great and a big
improvement over things like gevent (or even Twisted), like C#'s
async/await syntax it "infects" your code by making it necessary to yield
within (or in C#, mark async) any code that needs to run asynchronously.
It can become a fairly large burden to convert code from being synchronous
to asynchronous because it often affects large portions of your call stack.

Joe
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150224/51b82361/attachment.html>

From herrold at owlriver.com  Tue Feb 24 20:10:52 2015
From: herrold at owlriver.com (R P Herrold)
Date: Tue, 24 Feb 2015 14:10:52 -0500 (EST)
Subject: [CentralOH] =?iso-2022-jp?b?MjAxNS0wMi0yMyAbJEJQcjVEGyhCIFNjcmli?=
	=?iso-2022-jp?b?Ymxlcw==?=
In-Reply-To: <20150224125359.070a46d3.jep200404@columbus.rr.com>
References: <20150224125359.070a46d3.jep200404@columbus.rr.com>
Message-ID: <alpine.LRH.2.03.1502241409370.4991@bjyevire.pbz>

On Tue, 24 Feb 2015, jep200404 at columbus.rr.com wrote:

>     Python has unusually low defect rate in python itself.
>     http://www.coverity.com/press-releases/coverity-finds-python-sets-new-level-of-quality-for-open-source-software/

it is a curious press release that lacks a date on it, but 
this one does

-- Russ herrold

From jep200404 at columbus.rr.com  Tue Feb 24 20:46:45 2015
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Tue, 24 Feb 2015 14:46:45 -0500
Subject: [CentralOH] Dates for Coverity Python Defect Rate Report
In-Reply-To: <alpine.LRH.2.03.1502241409370.4991@bjyevire.pbz>
References: <20150224125359.070a46d3.jep200404@columbus.rr.com>
 <alpine.LRH.2.03.1502241409370.4991@bjyevire.pbz>
Message-ID: <20150224144645.257d50ac.jep200404@columbus.rr.com>

On Tue, 24 Feb 2015 14:10:52 -0500 (EST), R P Herrold <herrold at owlriver.com> wrote:

> On Tue, 24 Feb 2015, jep200404 at columbus.rr.com wrote:
> 
> >     Python has unusually low defect rate in python itself.
> >     http://www.coverity.com/press-releases/coverity-finds-python-sets-new-level-of-quality-for-open-source-software/
> 
> it is a curious press release that lacks a date on it, but 
> this one does

Try 2013-08-29 for the following (likely posted on 2013-09-02).
Was the scanning done in 2012? 

    http://www.itrpress.com/cp/2013/2013-09-02_300813-Python-Scan-Spotlight-PR.pdf

Other links:

    http://wpcme.coverity.com/wp-content/uploads/2013-Coverity-Scan-Spotlight-Python.pdf
    https://scan.coverity.com/news

I wonder what the defect rate for systemd is.

Andrew Tridgell was not at the meeting.

wp:Samba_(software)
wp:Andrew_Tridgell

From eric at intellovations.com  Tue Feb 24 21:05:36 2015
From: eric at intellovations.com (Eric Floehr)
Date: Tue, 24 Feb 2015 15:05:36 -0500
Subject: [CentralOH] Additional Go Language Influences
In-Reply-To: <CAOxvq7x7h3iDhMibgyzX91vbO-XV+vs_B8nMBD2tw0PxAP_F8A@mail.gmail.com>
References: <mailman.115574.1424800447.18129.centraloh@python.org>
 <54ECBC3D.1020904@atlantixeng.com>
 <CAOxvq7x7h3iDhMibgyzX91vbO-XV+vs_B8nMBD2tw0PxAP_F8A@mail.gmail.com>
Message-ID: <CAJzarMMFiz--9XdraGirPekgOoktLZ23Eg4fup0MtPm_LF+8zg@mail.gmail.com>

> Will Python develop a lightweight concurrency model?
>
>
> Python has some external projects which have introduced the idea of "green
> threads", such as greenlet and gevent.  However, I think Go's greatest
> strength is that the concurrency is baked in at a very fundamental level in
> the language and runtime.  Gevent for instance does some pretty scary
> monkeypatching of various low-level functions in places like the socket and
> os modules to achieve concurrency.
>

I agree that baking in concurrency at a fundamental level is Go's greatest
strength. I would argue however, that Python has baked in almost to the
same level concurrency, and that you rarely if ever need to use third-party
green thread implementations any more.

The main concepts are that generators are semi-coroutines, coroutines allow
for concurrency, and cocurrency is not multi-threading.

Both Python and Go by default implement concurrency on a single
thread/virtual processor. Go's advantages are that it is slightly easier to
grok goroutines because of less syntactic sugar needed (like the event loop
is implicit not explicit), and that you can more easily introduce
additional (virtual) processors (via runtime.GOMAXPROCS) whereas in Python
it's a little more difficult to introduce multi-threaded concurrency. Also,
Go's asynchronous I/O is built-in to the standard I/O libraries in Go
(that's changing in Python though).



> I think to get the kind of concurrency Go enjoys would require a Python
> 4-like re-breaking of the language syntax, which I think would be a tough
> sell. Maybe it could be done incrementally, I'm not sure.
>

I don't agree with this at all. To get everything that Go has, the way it
has it, maybe. But if you want to write Go, write Go. But to enjoy
concurrency as Go enjoys it (but perhaps implemented differently), it's
already there in Python.


One of the things I like best about Go is that goroutines allow you to
> write code in a very linear, sequential, non-concurrent fashion and add
> asynchronicity later.  If you look at my first example from the talk, the
> concurrent URL fetcher:
>
>      https://github.com/joeshaw/talks/blob/master/cohpy/fetch.go
>
>
notice that the fetch() function does not involve concurrency at all.
>

Right, but the reason that works is because Go provides non-blocking HTTP
and File operations by default. In Python 3 we get non-blocking file I/O,
and via third-party libs we can get non-blocking HTTP (aiohttp) and
hopefully that will be added in soon as more people convert to the
non-blocking sockets in Python 3.

So the only advantage with Go is that it isn't hindered by some blocking
legacy code, which is true of any shiny new language.


  It is how we use and compose that function later inside main() that makes
> the concurrency work.  It's a best practice in Go that APIs you write
> should not expose goroutines or channels but instead act synchronously.
> The consumers of your API should have the freedom to make them asynchronous
> by running them in a goroutine.
>

So how is Go's:

for i := range sites {
    site := sites[i]
    go func() {
        resultCh <- fetch(site)
    }()
}

for res := range resultCh {
    fmt.Println(res)
}


that different from Python 3's (assuming fetch used non-blocking http and
file i/o, as Go):

def func(site):
    result = yield from fetch(site)
    print result

funcs = [func(u) for u in sites]
asyncio.get_event_loop().run_until_complete(funcs)

Sure you don't have channels in this example, but we don't really need
them. And Go's event loop is implicit. I don't claim to be an expert in
Python 3's asyncio so there may be even better ways to do this, but I don't
really see any huge Go advantage or difference here.


While I think the asyncio stuff in Python is really great and a big
> improvement over things like gevent (or even Twisted), like C#'s
> async/await syntax it "infects" your code by making it necessary to yield
> within (or in C#, mark async) any code that needs to run asynchronously.
> It can become a fairly large burden to convert code from being synchronous
> to asynchronous because it often affects large portions of your call stack.
>

Coroutines have been first-class Python since 2.5, so sure, it's not baked
in from the beginning. So a Go programmer is more likely to use async and
goroutines from the beginning.

But I don't understand how making non-concurrent code in Go concurrent any
less "infectious" than making non-concurrent code in Python concurrent?

As noted from my example above, it's no more "burdensome" to make
non-concurrent "fetch()" in either Go or Python concurrent.

Anyway, I do enjoy what Go offers, and have been very interested in the
language. It does offer some cleaner syntax and built-in stuff, as well as
bringing less baggage :-) that make it appealing.

Cheers,
Eric
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150224/1b1282eb/attachment-0001.html>

From joe at joeshaw.org  Tue Feb 24 22:27:04 2015
From: joe at joeshaw.org (Joe Shaw)
Date: Tue, 24 Feb 2015 16:27:04 -0500
Subject: [CentralOH] Additional Go Language Influences
In-Reply-To: <CAJzarMMFiz--9XdraGirPekgOoktLZ23Eg4fup0MtPm_LF+8zg@mail.gmail.com>
References: <mailman.115574.1424800447.18129.centraloh@python.org>
 <54ECBC3D.1020904@atlantixeng.com>
 <CAOxvq7x7h3iDhMibgyzX91vbO-XV+vs_B8nMBD2tw0PxAP_F8A@mail.gmail.com>
 <CAJzarMMFiz--9XdraGirPekgOoktLZ23Eg4fup0MtPm_LF+8zg@mail.gmail.com>
Message-ID: <CAOxvq7zhyhZpi5bjRA=HHkEpXB+s+orWgU1DnhXSoaFJxA4k_g@mail.gmail.com>

Hi Eric,

On Tue, Feb 24, 2015 at 3:05 PM, Eric Floehr <eric at intellovations.com>
wrote:
>
> I think to get the kind of concurrency Go enjoys would require a Python
>> 4-like re-breaking of the language syntax, which I think would be a tough
>> sell. Maybe it could be done incrementally, I'm not sure.
>>
>
> I don't agree with this at all. To get everything that Go has, the way it
> has it, maybe. But if you want to write Go, write Go. But to enjoy
> concurrency as Go enjoys it (but perhaps implemented differently), it's
> already there in Python.
>

That's a good point, well said.


> One of the things I like best about Go is that goroutines allow you to
>> write code in a very linear, sequential, non-concurrent fashion and add
>> asynchronicity later.  If you look at my first example from the talk, the
>> concurrent URL fetcher:
>>
>>      https://github.com/joeshaw/talks/blob/master/cohpy/fetch.go
>>
>>
> notice that the fetch() function does not involve concurrency at all.
>>
>
> Right, but the reason that works is because Go provides non-blocking HTTP
> and File operations by default.
>

The main difference is that the Go runtime handles this, rather than
pushing it onto the programmer.  The code you write in Go appears
synchronous and the runtime handles yielding to other goroutines, whereas
in Python you have to explicitly yield.  (I wonder if this is something the
Python runtime could handle. I have some vague notion that another Python
implementation like PyPy or stackless Python might in fact do this.)

So how is Go's:
>
> for i := range sites {
>     site := sites[i]
>     go func() {
>         resultCh <- fetch(site)
>     }()
> }
>
> for res := range resultCh {
>     fmt.Println(res)
> }
>
>
> that different from Python 3's (assuming fetch used non-blocking http and
> file i/o, as Go):
>
> def func(site):
>     result = yield from fetch(site)
>     print result
>
> funcs = [func(u) for u in sites]
> asyncio.get_event_loop().run_until_complete(funcs)
>
> Sure you don't have channels in this example, but we don't really need
> them. And Go's event loop is implicit. I don't claim to be an expert in
> Python 3's asyncio so there may be even better ways to do this, but I don't
> really see any huge Go advantage or difference here.
>

This part is basically the same, but inside the fetch() function the Go
looks like it is a linear, blocking function while the Python one still has
an explicit yield in it (res = yield from aiohttp.get(site)) which
transforms it from returning a simple value to returning a generator.

You're right about the channel... it's not really necessary in the Go
version either.  A better example might be this one from my code camp talk:
https://github.com/joeshaw/talks/blob/master/codecamp/concurrency2.go

There I'm using channels more to build a pipeline: three independent,
concurrently running "machines": one that reads lines from
/usr/share/dict/words, one that gathers definitions from the OS X directory
services with 10 concurrent workers, and one that prints out the
definitions.

While I think the asyncio stuff in Python is really great and a big
>> improvement over things like gevent (or even Twisted), like C#'s
>> async/await syntax it "infects" your code by making it necessary to yield
>> within (or in C#, mark async) any code that needs to run asynchronously.
>> It can become a fairly large burden to convert code from being synchronous
>> to asynchronous because it often affects large portions of your call stack.
>>
>
> Coroutines have been first-class Python since 2.5, so sure, it's not baked
> in from the beginning. So a Go programmer is more likely to use async and
> goroutines from the beginning.
>
> But I don't understand how making non-concurrent code in Go concurrent any
> less "infectious" than making non-concurrent code in Python concurrent?
>

"Infectious" was perhaps a bad word choice because of its negative
connotation.  But what I meant by that was that to turn blocking Python
code into asyncio-friendly code you must yield a generator and either (a)
find a drop-in replacement like aiohttp more or less is for requests or (b)
use threading to bridge the blocking library with asyncio.

With the generator you need to explicitly unwrap it with something like
`run_until_complete` (and so it looks a lot like a Promise to me).  C# 5 is
similar in that functions have to be explicitly tagged `async` and then
`await` when in Python you would `yield`.

Quickly you can get into a situation where functions are nested and
cascading yields.  This was a common thing on a project I worked on in
Javascript (on Mozilla's spidermonkey, which had co-routines) where we had
implemented promises. It's definitely an improvement on "callback hell"
common in Node.js code but I think is still trickier than the
straightforwardness of Go's flow.

As mentioned earlier, the implicit event loop and yielding to the runtime
in Go make it unnecessary.


> Anyway, I do enjoy what Go offers, and have been very interested in the
> language. It does offer some cleaner syntax and built-in stuff, as well as
> bringing less baggage :-) that make it appealing.
>

Yeah, and I am not hating on Python, by the way.  I love it and still use
it.  I remember the bad old days of pre-coroutine Twisted deferreds and
asyncio is a breath of fresh air.  The closer Python can get to Go's
strengths in concurrency are positive for everyone... especially if you
strongly prefer Python to Go otherwise. :)  Happy feelings all around.

I won't drag out the thread any longer, but there was a great blog post
about asyncio recently:
http://www.onebigfluke.com/2015/02/asyncio-is-for-composition.html and a
follow-up: http://www.onebigfluke.com/2015/02/ghost-of-threading-past.html

Joe
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150224/0f078324/attachment.html>

From jep200404 at columbus.rr.com  Wed Feb 25 01:41:55 2015
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Tue, 24 Feb 2015 19:41:55 -0500
Subject: [CentralOH] _ for variables that are never referenced
In-Reply-To: <20150221114913.7bcefa76.jep200404@columbus.rr.com>
References: <20150221114913.7bcefa76.jep200404@columbus.rr.com>
Message-ID: <20150224194155.32577a53.jep200404@columbus.rr.com>

On Sat, 21 Feb 2015 11:49:13 -0500, jep200404 at columbus.rr.com wrote:

> for _ in range(n):  # For when the loop variable is never referenced.

    Python examples

        >>> from random import randint
        >>> for _ in range(5):
        ...     print randint(0, 10-1)
        ...
        8
        4
        7
        4
        1
        >>> [randint(0, 10-1) for _ in range(5)]
        [0, 9, 2, 2, 9]
        >>>

    Go

        Using _ for name of unused variables is standard practice in Go.
        The _ is called the blank identifier.

        Joe Shaw address this in his presentation. 
        For example, see line 267 of
        https://github.com/joeshaw/talks/blob/master/cohpy/zen.slide

            for _, row := range table { ...

From jep200404 at columbus.rr.com  Wed Feb 25 01:46:13 2015
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Tue, 24 Feb 2015 19:46:13 -0500
Subject: [CentralOH] =?utf-8?b?MjAxNS0wMi0yMyDmnIPorbAgU2NyaWJibGU6IE9T?=
	=?utf-8?q?U_Hackathon_Sponsor?=
Message-ID: <20150224194613.4e68dd4a.jep200404@columbus.rr.com>

Andrew Kubara said that OSU was looking for a sponsor for its Hackathon.

From jep200404 at columbus.rr.com  Wed Feb 25 01:54:33 2015
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Tue, 24 Feb 2015 19:54:33 -0500
Subject: [CentralOH] =?utf-8?q?2015-02-23_=E6=9C=83=E8=AD=B0_Scribbles_?=
 =?utf-8?b?76SY5pu4L+aDoeaWhz86IGdvLCB3ZWxsIHRlbXBlcmVkIExhcnMgb24gTWFy?=
 =?utf-8?q?s=2C_C++_in_iPython_notebook?=
In-Reply-To: <20150224125359.070a46d3.jep200404@columbus.rr.com>
References: <20150224125359.070a46d3.jep200404@columbus.rr.com>
Message-ID: <20150224195433.650db0ca.jep200404@columbus.rr.com>

On Tue, 24 Feb 2015 12:53:59 -0500, jep200404 at columbus.rr.com wrote:

> We look forward to seeing posted:

>     Joe Shaw's slides

He already posted them: 

   https://github.com/joeshaw/talks/tree/master/cohpy

Thanks Joe!

>     video of K Lars Lohn's PyTn presentation

Perhaps http://www.youtube.com/watch?v=lAK6WdGZKA0

>     technique for doing C++ in Ipython notebook
>     Jim Reed's slides
          (or URLs)

still waiting

From eric at intellovations.com  Wed Feb 25 02:02:01 2015
From: eric at intellovations.com (Eric Floehr)
Date: Tue, 24 Feb 2015 20:02:01 -0500
Subject: [CentralOH] =?utf-8?q?2015-02-23_=E6=9C=83=E8=AD=B0_Scribbles_?=
	=?utf-8?b?76SY5pu4L+aDoeaWhz86IGdvLCB3ZWxsIHRlbXBlcmVkIExhcnMgb24g?=
	=?utf-8?q?Mars=2C_C++_in_iPython_notebook?=
In-Reply-To: <20150224195433.650db0ca.jep200404@columbus.rr.com>
References: <20150224125359.070a46d3.jep200404@columbus.rr.com>
 <20150224195433.650db0ca.jep200404@columbus.rr.com>
Message-ID: <CAJzarMN_-JjHEiY1SYYqfuR30dML0jBaatQssxonvRf6RMrkrg@mail.gmail.com>

> still waiting
>

He commented directly on the Meetup page:

"""

Thanks for all who stayed in for my continuing talk on using If's for
decision making correctly for Python.

Here's a link to my code:
https://github.com/profjrr/COhPy2015.git

And the link to the NASA/JPL coding standards as
discussed:
http://lars-lab.jpl.nasa.gov/JPL_Coding_Standard_C.pdf Thanks again,
Professor Reed...

"""
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150224/9f0ddf52/attachment.html>

From brian.costlow at gmail.com  Wed Feb 25 04:36:41 2015
From: brian.costlow at gmail.com (Brian Costlow)
Date: Tue, 24 Feb 2015 22:36:41 -0500
Subject: [CentralOH] =?utf-8?q?2015-02-23_=E6=9C=83=E8=AD=B0_Scribbles_?=
	=?utf-8?b?76SY5pu4L+aDoeaWhz86IGdvLCB3ZWxsIHRlbXBlcmVkIExhcnMgb24g?=
	=?utf-8?q?Mars=2C_C++_in_iPython_notebook?=
In-Reply-To: <CAJzarMN_-JjHEiY1SYYqfuR30dML0jBaatQssxonvRf6RMrkrg@mail.gmail.com>
References: <20150224125359.070a46d3.jep200404@columbus.rr.com>
 <20150224195433.650db0ca.jep200404@columbus.rr.com>
 <CAJzarMN_-JjHEiY1SYYqfuR30dML0jBaatQssxonvRf6RMrkrg@mail.gmail.com>
Message-ID: <CACLJ_dH-Nt2+EdFS9rSNir_rWJkM80=KNeMm0wDub=-xm==WXg@mail.gmail.com>

Some more bits of K Lahrs talk

https://www.youtube.com/watch?v=GHyh-UKAPxQ

https://www.youtube.com/watch?v=ja3RNHPpQEw

In the second clip, be sure to watch the musical score for some extra
"programmer" notation.

On Tue, Feb 24, 2015 at 8:02 PM, Eric Floehr <eric at intellovations.com>
wrote:

>
> still waiting
>>
>
> He commented directly on the Meetup page:
>
> """
>
> Thanks for all who stayed in for my continuing talk on using If's for
> decision making correctly for Python.
>
> Here's a link to my code:
> https://github.com/profjrr/COhPy2015.git
>
> And the link to the NASA/JPL coding standards as
> discussed:
> http://lars-lab.jpl.nasa.gov/JPL_Coding_Standard_C.pdf Thanks again,
> Professor Reed...
>
> """
>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20150224/04edd0e0/attachment.html>

From jep200404 at columbus.rr.com  Wed Feb 25 16:29:05 2015
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Wed, 25 Feb 2015 10:29:05 -0500
Subject: [CentralOH] =?utf-8?b?MjAxNC0xMS0xNCDpgZPloLQgU2NyaWJibGVzOiBy?=
 =?utf-8?q?unning=5F*_--=3E_toolz=2Eaccumulate?=
In-Reply-To: <20141117095541.747e03f8.jep200404@columbus.rr.com>
References: <20141117095541.747e03f8.jep200404@columbus.rr.com>
Message-ID: <20150225102905.08dd7a07.jep200404@columbus.rr.com>

On Mon, 17 Nov 2014 09:55:41 -0500, jep200404 at columbus.rr.com wrote:

> def running_op(iterable, op=operator.add, initial=0):
>     running_result = initial
>     for element in iterable:
>         running_result = op(running_result, element)
>         yield running_result
> 
> def running_sum(iterable, initial=0):
>     sum_ = initial
>     for element in iterable:
>         sum_ += element
>         yield sum_

Compare those with toolz.accumulate().

import toolz
from operator import add, mul
print list(toolz.accumulate(add, [1, 2, 3, 4, 5]))
print list(toolz.accumulate(mul, [1, 2, 3, 4, 5]))
print reduce(add, [1, 2, 3, 4, 5])
print reduce(mul, [1, 2, 3, 4, 5])

http://colug.net/python/cohpy/20131029/