Python package installed globally, but not in a virtualenv (PyGTK)

Question

I'm having some strange issues with PyGTK in "virtualenv". gtk does not import in my virtualenv, while it does import in my global python install. (I wasn't having this particular issue last week, guessing some software update upset something.)

Is there a good way to resolve this behavior?

Shown here: importing gtk globally,

tom@zeppelin:~$ python
Python 2.7.1+ (r271:86832, Sep 27 2012, 21:12:17) 
[GCC 4.5.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import gtk
>>> gtk
<module 'gtk' from '/usr/lib/pymodules/python2.7/gtk-2.0/gtk/__init__.pyc'>

and then failing to import gtk,

tom@zeppelin:~$ workon py27
(py27)tom@zeppelin:~$ python
Python 2.7.1+ (r271:86832, Sep 27 2012, 21:12:17) 
[GCC 4.5.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import gtk
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named gtk

Unfortunately, this has broken my ipython --pylab environment: http://pastebin.com/mM0ur7Hc

UPDATE: I was able to fix this by adding symbolic links as suggested by grepic / this thread: Python: virtualenv - gtk-2.0

with a minor difference, namely that my "cairo" package was located in /usr/lib/pymodules/python2.7/cairo/ rather than in /usr/lib/python2.7/dist-packages/cairo.

SECOND UPDATE: I also found it useful to add the following lines to my venv/bin/activate:

export PYTHONPATH=$PYTHONPATH:/home/tom/.virtualenvs/py27/lib/python2.7/dist-packages
export PYTHONPATH=$PYTHONPATH:/home/tom/.virtualenvs/py27/lib/python2.7/dist-packages/gtk-2.0
export PYTHONPATH=$PYTHONPATH:/usr/lib/pymodules/python2.7/gtk-2.0

(I suspect that one or more of these is unneccessary, but I've been fiddling around with this for too long and have decided to stop investigating -- my setup now works and so I'm satisfied.)

Problem solved! Thanks everyone.

Answer 1

Try creating your virtual environment with the --system-site-packages flag.