Hello, When a python source block has a :session header argument, the python version selected does not appear to respect the value of the variable org-babel-python-command.
Starting emacs with this in the init file (.emacs): (require 'org-install) (org-babel-do-load-languages 'org-babel-load-languages '((python . t) )) (setq org-babel-python-command "python2") And in my org file: #+begin_src python :results output import sys print(sys.version) #+end_src #+results: : 2.7.2 (default, Jun 29 2011, 11:10:00) : [GCC 4.6.1] Now, exactly the same but with ":session x" header argument: #+begin_src python :results output :session x import sys print(sys.version) #+end_src #+results: : : 3.2.1 (default, Jul 11 2011, 12:37:47) : [GCC 4.6.1] So babel has chosen to use Python 3.2 When I wanted to use Python 2.7, as in the first block, and the value of org-babel-python-command is still "python2". Part of the documentation for the variable python-python-command is: "Shell command to run Python interpreter". On my system to run the Python 2.7 interpreter I would do: $ python2 at the command line so, setting this variable thus: #+begin_src elisp (setq python-python-command "python2") #+end_src #+results: : python2 and then using the two examples from above again gives the same (correct) results for the block without the :session header argument: #+begin_src python :results output import sys print(sys.version) #+end_src #+results: : 2.7.2 (default, Jun 29 2011, 11:10:00) : [GCC 4.6.1] but a different error for the block with the session argument: #+begin_src python :results output :session x import sys print(sys.version) #+end_src results in the message: "python-check-version: Only Python versions >= 2.2 and < 3.0 are supported" Versions on my system are: orgmode commit cae9f947be (Aug 30th) GNU Emacs 23.3.1 (x86_64-unknown-linux-gnu, GTK+ Version 2.22.1) of 2011-03-10 on bitzer.hoetzel.info $ ls -l `which python{2,3,}` /usr/bin/python -> python3 /usr/bin/python2 -> python2.7 /usr/bin/python3 Am I doing something wrong or is this a bug? I am wondering if it is reasonable to expect emacs/orgmode to be able to deal with the fact that I have Python 3 installed. Thanks, Myles