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

Answer 1

It is now possible to resolve this using vext. Vext allows you to install packages in a virtualenv that individually access your system packages. To access PyGTK, do the following:

pip install vext
pip install vext.pygtk

Answer 2

Another way to do this is to create a .pth file in your virtualenv's site-packages dir

eg

(in <virtualenv>/lib/python2.7/site-packages/dist-packages.pth)

/usr/lib/python2.7/dist-packages/

This fixed the issue I was having with apt-get installed version of pycairo

Answer 3

So gtk normally lives in a place like /usr/lib/python2.7/dist-packages which is in your Python path in your global environment, but not in your virtual environment.

You may wish to just add the path to gtk manually with something like

import sys
sys.path.append("/usr/lib/python2.7/dist-packages/gtk")

You could also change the path when you activate the virtual environment. Open up venv/bin/activate. Its a scary looking file, but at the end you can just put:

export PATH=$PATH:/my/custom/path

Save that and the next time you activate the virtual environment with:

source venv/bin/activate

your custom path will be in the path. You can verify this with

echo $PATH

An alternative approach suggested Python: virtualenv - gtk-2.0 is to go into your virtualenv directory and add a 'dist-packages' directory and create symbolic links to the gtk package you were using previously:

mkdir -p venv/lib/python2.7/dist-packages/
cd venv/lib/python2.7/dist-packages/

For GTK2:

ln -s /usr/lib/python2.7/dist-packages/glib/ glib
ln -s /usr/lib/python2.7/dist-packages/gobject/ gobject
ln -s /usr/lib/python2.7/dist-packages/gtk-2.0* gtk-2.0
ln -s /usr/lib/python2.7/dist-packages/pygtk.pth pygtk.pth
ln -s /usr/lib/python2.7/dist-packages/cairo cairo

For GTK3:

ln -s /usr/lib/python2.7/dist-packages/gi gi

Full disclosure: I feel that both these solutions are somewhat hackish, which is ok given that you say the question is urgent. There is probably a 'proper' way to extend a virtual environment so let us know if you eventually discover the better solution. You may have some luck with http://www.virtualenv.org/en/latest/index.html#creating-your-own-bootstrap-scripts

Answer 4

If you want to include the links to the relevant system's python gtk-2.0 in the virtualenv, you can just use pip to install ruamel.venvgtk:

pip install ruamel.venvgtk

You don't have import anything, the links are setup during installation.

This is especially handy if you are using tox, in that case you only need to include the dependency (for tox):

deps:
    pytest
    ruamel.venvgtk

and a newly setup python2.7 environment will have the relevant links included before the tests are run.

Answer 5

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