Re: [O] python sessions

[Eric Schulte]

John Hendy <address@hidden> writes:

> On Mon, Mar 25, 2013 at 11:01 AM, Ista Zahn <address@hidden> wrote:
>> On Mon, Mar 25, 2013 at 11:40 AM, Eric Schulte <address@hidden> wrote:
>>> John Hendy <address@hidden> writes:
>>>
>>>> On Sun, Mar 24, 2013 at 9:38 PM, Nick Dokos <address@hidden> wrote:
>>>>> Eric Schulte <address@hidden> wrote:
>>>>>
>>>>>> >
>>>>>> > From participating in evaluating code throughout the discussion and
>>>>>> > catching the comments throughout, I'd say yes, at least in terms of
>>>>>> > how other babel languages function. In other words =#+begin_src R
>>>>>> > :session foo= creates an R session named "foo" whereas doing the same
>>>>>> > with =python= instead of =R= does not yield a named session.
>>>>>> >
>>>>>> > From what others experienced, however, the functionality was working
>>>>>> > correctly (results were persistent across blocks and two differently
>>>>>> > names blocks created two different sessions), just not named
>>>>>> > correctly.
>>>>>> >
>>>>>>
>>>>>> See the cond form starting at line 169 in ob-python.el.  Different
>>>>>> session functionality is used based on the `org-babel-python-mode'
>>>>>> variable, and on the version of Emacs in use (prior to 24.1 or not).
>>>>>>
>>>>>> The branch taken when `org-babel-python-mode' equals 'python is
>>>>>> certainly broken, as it never saves the name of the newly created
>>>>>> buffer, so session re-use and use of multiple named sessions probably
>>>>>> works only when `org-babel-python-mode' equals 'python-mode.
>>>>>>
>>>>>
>>>>> That's me: org-babel-python-mode's value is python, so it's no wonder
>>>>> it's broken given what Eric says. I'm on emacs 24.3.50 where there is
>>>>> python.el but no python-mode.el. I tried the "cheap" workaround of
>>>>> switching the value to python-mode, but that does a (require
>>>>> 'python-mode) somewhere, so that option is out as well.
>>>>
>>>> I'm on Emacs 24.3.1 and have no python-mode.el, either (only
>>>> python.el). My setup is working correctly (again, with the caveat of
>>>> not having named sessions).
>>>>
>>>
>>> It sounds like we have the same setup, and the following un-named
>>> session example does not work for me.  The first code block evaluates
>>> successfully, but it doesn't appear to be having any impact on the
>>> default session (e.g., in the *Python* buffer).
>>>
>>>     Returns the value of x as expected.
>>>
>>>     #+begin_src python :session
>>>       x = 1
>>>       return x
>>>     #+end_src
>>>
>>>     #+RESULTS:
>>>     : 1
>>>
>>>     #+begin_src python :session
>>>       return x
>>>     #+end_src
>>>
>>>     #+RESULTS:
>>>
>>> The second code block /should/ have access to the x variable defined
>>> previous, but instead it throws an error because x is undefined.
>>>
>>> Currently I'd say session support for python is completely broken.
>>
>> As of this morning I've joined the "it does not work" crowd. Python
>> sessions worked for me last week, but are now completely broken for me
>> in the way Eric and others describe.
>
> Interesting... checked out back to that commit
> (eff59a15d76647ce8282626b9eb463dc3706d56e) and it still doesn't work.
> On a whim, I checked my pacman log (Arch's install system) and
> coincidentally on Mar 20 /after/ I wrote that post in which things
> work, I ran a system package update.
>
> $ grep -i emacs /var/log/pacman.log
>
> [2013-03-20 12:51] upgraded emacs (24.2-4 -> 24.3-1)
>
> Using the Arch Rollback Machine, I downloaded Emacs 24.2.4 and
> downgraded (also required downgrading imageMagick from 6.8.3.10 ->
> 6.8.2.3). Now it works again (refer to the reproducible example from
> the mailing list post):
> - http://www.mail-archive.com/address@hidden/msg68238.html
>
> Eric, your example fails for me. I get:
>

Yes, because my example only works in external (non session) execution
with the current buggy code, where as your example works with session
execution in the old working code.

>
>>>> x = 1
>>>> return x
>   File "<stdin>", line 1
> SyntaxError: 'return' outside function
>
> This works, hoever:
>
> #+begin_src python :session
>       x = 1
>       x
> #+end_src
>
> #+RESULTS:
> : 1
>
> #+begin_src python :session
>       x
> #+end_src
>
> #+RESULTS:
> : 1
>
> So, with emacs 24.2.4 and current Org-mode (pulled just now) and clean
> make, *both* named and un-named sessions work for me on Arch Linux.
>

Aha! Thanks for sleuthing this out.  So the problem lies in changes to
the python.el distributed with Emacs.  I don't suppose we can ask
whoever made these changes to python.el to fix the breakage they've
caused in Org-mode?

Thanks,

-- 
Eric Schulte
http://cs.unm.edu/~eschulte