title: Python can't find packages in Virtual Environment
body: <p>I'm trying to setup my environment for a project but python isn't able to find the modules I've installed with pip.</p>
  
  <p>I did the following:</p>
  
  <pre><code>mkdir helloTwitter
  cd helloTwitter
  virtualenv myenv
  Installing setuptools, pip, wheel...done.
  source myenv/bin/activate
  
  pip install tweepy
  Collecting tweepy
    Using cached tweepy-3.5.0-py2.py3-none-any.whl
  Collecting six&gt;=1.7.3 (from tweepy)
    Using cached six-1.10.0-py2.py3-none-any.whl
  Collecting requests&gt;=2.4.3 (from tweepy)
    Using cached requests-2.11.1-py2.py3-none-any.whl
  Collecting requests-oauthlib&gt;=0.4.1 (from tweepy)
    Using cached requests_oauthlib-0.6.2-py2.py3-none-any.whl
  Collecting oauthlib&gt;=0.6.2 (from requests-oauthlib&gt;=0.4.1-&gt;tweepy)
  Installing collected packages: six, requests, oauthlib, requests-oauthlib, tweepy
  Successfully installed oauthlib-2.0.0 requests-2.11.1 requests-oauthlib-0.6.2 six-1.10.0 tweepy-3.5.0
  </code></pre>
  
  <p>When I try to import the module it says it cannot be found.</p>
  
  <p>The first entry in $PATH is <code>helloTwitter/myenv/bin</code>
  All the packages are showing up in the environments site-packages directory.
  I seem to be using the right python and pip.
  Which python outputs <code>helloTwitter/myenv/bin/python</code>
  Which pip outputs <code>helloTwitter/myenv/bin/pip</code></p>
  
  <p>Any advice on where I'm going wrong?</p>