title: Should I be creating a virtual environment for each project?
body: <p>After googling around regarding virtualenv, I was under the impression that virtual environments should be created for every project I create (that are related and use the same site packages).</p>
  
  <p>Is this true and why or why not?</p>
  
  <p>Also, if I am currently using a virtualenv for one of my projects, how would I go about upgrading when upgrades for the packages come along?</p>