Re: Fwd: run python from org, draft

[Eric Schulte <schulte.eric@gmail.com>]

John Hendy <jw.hendy@gmail.com> writes:

> On Fri, Mar 29, 2013 at 10:09 AM, Eric Schulte <schulte.eric@gmail.com>wrote:
>
>> >> with current
>> >>
>> >> GNU Emacs 24.3.1 (i686-pc-linux-gnu, GTK+ Version 2.24.14) of 2013-03-05
>> >>
>> >> Org-mode version 7.9.3f (release_7.9.3f-17-g7524ef @
>> >> MY_PATH/emacs-24.3/lisp/org/)
>> >>
>> >> python from org-source seems completely broken.
>> >>
>> >> For example:
>> >>
>> >> #+BEGIN_SRC python
>> >> 1+2
>> >> #+END_SRC
>> >>
>> >> #+RESULTS:
>> >> : None
>> >>
>> >>
>> > Weird. With all the testing we did last week, I'm surprised that this is
>> > the case with me as well. I'm also getting no results with Org 8.0-pre
>> and
>> > Emacs 24.3.1.
>> >
>>
>> Because of quirks of the python language, when executing outside of a
>> session, it is necessary to explicitly specify a return.
>>
>> For example.
>>
>>     #+begin_src python
>>       return 1+2
>>     #+end_src
>>
>>     #+RESULTS:
>>     : 3
>>
>> or
>>
>>     #+begin_src python :return x
>>       x = 1+2
>>     #+end_src
>>
>>     #+RESULTS:
>>     : 3
>>
>> This is clearly stated in the Python documentation on Worg.
>> http://orgmode.org/worg/org-contrib/babel/languages/ob-doc-python.html
>>
>>
> This isn't working for me on Org-8.0 (from that Worg page):
>
> #+begin_src python :session
> def foo(x):
>   if x>0:
>     return x+1
>   else:
>     return x-1
>
> foo(1)
> #+end_src
>
> #+RESULTS:
> : None
>

As we've proven a couple of times now, Python session are broken with
the newest version of Emacs (since the upstream change to an entirely
new python.el implementation).  That is the cause of your example above.

>
> I tend to agree. I don't/haven't used Python, but having now read the
> ob-doc-python bit, it seems peculiar/undesirable to have to change
> indenting, line breaking, and return statements depending on :session or
> not...
>

I'd refer you to the previous discussion on the mailing list.  I
personally don't use Python and don't care, but others who have used
Python more extensively than you or I argued for the existing behavior,
so I'd rather not change it back capriciously.

Thanks,

>
> John
>
>
>
>> Thanks,
>>
>> --
>> Eric Schulte
>> http://cs.unm.edu/~eschulte
>>

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