title: python virtualenv installed packages cannot be imported
body: <p>Have a strange problem. I installed a module (cherrypy) into a python venv, but my script can't import it. Is there a problem with the way I'm installing it?</p>
  
  <pre><code>(venv)[leon@leon-1 project]$ sudo python server.py 
  Traceback (most recent call last):
    File "server.py", line 2, in &lt;module&gt;
      import cherrypy
  ImportError: No module named cherrypy
  (venv)[leon@leon-1 project]$ pip install cherrypy
  Requirement already satisfied (use --upgrade to upgrade): cherrypy in ./venv/lib/python2.7/site-packages
  </code></pre>