title: How to setup Emacs to use a given Python virtualenv?
body: <p>I use Emacs for a number of tasks and as I am starting to work with Python I would like to keep using Emacs to code in Python.</p>
  
  <p>I have set up a virtualenv for Python3, and it is working as desired. I also have Emacs 24.5 installed with the latest version of <a href="http://batsov.com/prelude/" rel="noreferrer">Emacs Prelude</a>.</p>
  
  <p>When I edit an Python source file all I expected is working -- code completion, object inspection, etc. -- but for my system wide Python installation, not for the virtual environment I have set up for the project.</p>
  
  <p>How can I tell Emacs to use the virtual environment for a given project?</p>