Question

If I am working on a shared web server with Python and some other packages like virtualenv already installed. Can I use virtualenv to install some additional packages I need in a specific directory while still using the system wide python and packages or better still can I just install the additional python packages in my own directory and use them for my website without requiring sudo permissions?

Answer 1

You can explicitly include all globally installed packages in your virtualenv with the --system-site-packages switch:

Give access to the global site-packages dir to the virtual environment

or disable global site packages with the --no-site-packages switch instead:

Don’t give access to the global site-packages dir to the virtual environment

The latter is currently the default.

I personally have lxml installed in my global site packages, so we can use that as a small demonstration:

$ virtualenv nositepackages
New python executable in nositepackages/bin/python
Installing setuptools............done.
Installing pip...c............done.
$ ./nositepackages/bin/python -c 'import lxml; print lxml.__package__'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ImportError: No module named lxml
$ virtualenv --system-site-packages sitepackages
New python executable in sitepackages/bin/python
Installing setuptools............done.
Installing pip...............done.
$ ./sitepackages/bin/python -c 'import lxml; print lxml.__package__'
lxml