On Feb 4, 2010, at 5:06 AM, Scott May wrote:

> Using org-babel, the following example produces no output for me  
> when I execute using C-c C-c:
>
> #+begin_src python :results value
> 2 + 2
> #+end_src
>
> #+results:
> : None
>
> In my messages buffer I see the following:
>
> : (Shell command succeeded with no output)
>
> Now the equivalent emacs-lisp example does work:
>
> #+begin_src emacs-lisp :results value
> (+ 2 2)
> #+end_src
>
> #+results:
> : 4
>
> Furthermore,
>
> #+begin_src python :results output
> print(2 + 2)
> #+end_src
>
> #+results:
> : 4
>
> works as expected.
>
> Am I missing something obvious? Is the problem with my python setup,  
> or perhaps org-babel-python?
>
> I have tested this on both my Windows and Ubuntu setups. I am using  
> org version 6.34trans.
>
> Cheers,
> Scott
>

Hi Scott,

You need :session.

#+begin_src python :session :results value
2 + 2
#+end_src

#+results:
: 4

hth,
Tom

Thomas S. Dye, Ph.D.
T. S. Dye & Colleagues, Archaeologists, Inc.
Phone: (808) 529-0866 Fax: (808) 529-0884
http://www.tsdye.com