title: Virtualenv / pip installation log?
body: <p>Do <code>pip</code> or <code>virtualenv</code> keep a log of installations?</p>
  
  <p>E.g. Say I create a virtualenv and install a package in it.</p>
  
  <pre><code>&gt; source [my virtual env]/bin/activate
  &gt; pip install matplotlib
  </code></pre>
  
  <p>Is there a place where a log of the package installation is kept? </p>
  
  <p>If not, what would be a good way to log package installations ? (other than manually copying the output of <code>pip install</code> to a text file)</p>