title: issues with getsitepackages under a virtualenv
body: <p>I wanted to check out which Python interpreter was running under my virtual env so I just entered the virtualenv and used getsitepackages. This is what came out.</p>
  
  <pre><code>(test)~/Documents/Development/test$ python
  Python 2.7.9 (default, Apr  7 2015, 07:58:25) 
  [GCC 4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.57)] on darwin
  Type "help", "copyright", "credits" or "license" for more information.
  &gt;&gt;&gt; import site
  &gt;&gt;&gt; print site.getsitepackages()
  Traceback (most recent call last):
  File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  AttributeError: 'module' object has no attribute 'getsitepackages'
  &gt;&gt;&gt;
  </code></pre>
  
  <p>Is this normal behaviour when operating under a virtualenv? If possible how would I correct, or should I even bother? </p>