title: Set python virtualenv in vim
body: <p>I use vim for coding and for python coding in particular. Often I want to execute the current buffer with python interpreter. (for example to run unittests), usually I do this with <code>:!python % &lt;Enter&gt;</code> </p>
  
  <p>This scenatio will work works fine with global python, but I want to run virtualenv python instead. How do I enable virtualenv within vim? Is it possible to switch virtualenv on the runtime?</p>
  
  <p>I'm using macvim</p>