How to set site-packages directory for local Python 2.7 install

Question

I'm trying to run a certain script in Python, but it requires some other modules (setuptools) - I don't have write permissions for our /usr/ directory to install them, so I'm trying to install a local version of Python 2.7 to run it (not in /usr/).

When I try to run the ez_setup script for setuptools, it tries to access:

/usr/local/lib/python2.7/site-packages/

But that's not the installation I want (I get write permission error). I can point the ez_setup script to wherever, but I'm not sure how to get Python to use it. In my 2.7 install I ran:

site.getsitepackages()
['/usr/local/lib/python2.7/site-packages', '/usr/local/lib/site-python'].

Is there a way to change the default site-packages directory so I can do local installs? Like in the Python installation directory itself?

Thanks, Kaleb

Answer 1

You really want to read up on Python virtual environments , which allow you to create a "local" Python tree into which you can install your own packages and such without requiring root access.

For example, assuming that you have the virtualenv command available (you may need to install this first; it's available as a package for most major distributions), you can create a new virtual environment like this:

virtualenv --system-site-packages myenv

The --system-site-packages option will make any packages in your system site-packages directory visible to this environment, as well as anything you install locally. Then activate the environment:

. myenv/bin/activate

And install stuff:

pip install apackage

NB For no good reason, pydoc will stop working for you in this configuration. You can just drop a new pydoc script into myenv/bin/pydoc that looks like this:

#!/usr/bin/env python

import pydoc
if __name__ == '__main__':
    pydoc.cli()