title: PYTHONPATH variable blank
body: <p>According to <a href="https://docs.python.org/2/library/sys.html" rel="nofollow noreferrer">documentation</a>, sys.path is initialized from PYTHONPATH when python session starts. However, in my case, PYTHONPATH variable is empty. When I execute this in terminal:</p>
  
  <pre><code>echo $PYTHONPATH
  </code></pre>
  
  <p>it returns blank. On the other hand, when I start python and inspect sys.path:</p>
  
  <pre><code>import sys
  print (sys.path)
  </code></pre>
  
  <p>I get back a long list of paths. Where do those get loaded from? What am I missing?</p>