title: Python pip: install in specific non-user directory and ignore system wide packages
body: <p>I want to set up a Python environment for a whole team and I don't have root access to the server. </p>
  
  <p>I have done a similar thing with Perl and expected to be able to do this for Python in a similar way but I keep running into a problem.</p>
  
  <p>Basically, I want to be able to install a package into /SOME/DIR on the system while ignoring any system wide versions of that package.
  However, when I run </p>
  
  <pre><code>pip install --install-option="--prefix=/SOME/DIR/" --up --ignore-installed SOME-MODULE
  </code></pre>
  
  <p>I keep getting a "permission denied" error because pip keeps trying to remove system-wide packages when upgrading.
  What does work is this</p>
  
  <pre><code>pip install --user --up --ignore-installed SOME-MODULE
  </code></pre>
  
  <p>Which does <strong>not</strong> try to touch the system-wide packages but it installs the module into a directory in $HOME/.lib, which is not what I need.</p>
  
  <p>It seems impossible to combine --user and a "--prefix" option, so it sems that I can <em>either</em> install into an arbitrary path but then get conflicts with already install system-wide packages or install into my home directory. Neither of them are what I need.
  For now I have been using the --user option and then moved the installed files across to /SOME/DIR which works but seems odd.</p>
  
  <p>Am I missing something? I have read up on virtualenv but this also doesn't quite sound like what I need. Thanks for your help!</p>