title: Best way to define Python installation path
body: <p>I'm quite confused about the best way to define my Python installation paths. For some reason I use multiple versions of python with multiple versions of numpy, scipy and matplotlib, and with multiple versions of gcc.</p>
  
  <p>For the moment, I use paths like <code>/softs/python/2.7.6/numpy/1.8.0/scipy/0.13.3/matplotlib/1.3.1/64/gcc/4.7.2</code> but its quite complicated to identify the number of installed versions, for wich I have a 32-bit version, etc...</p>
  
  <p>Is there a better common way to have multiple versions of packages in Python and manage the paths ?</p>