title: Export of PYTHONPATH from .zshrc not working
body: <p>I'm trying to export the PYTHONPATH environment variable from my .zshrc, but fails.</p>
  
  <p><strong>relevant lines from .zshrc</strong></p>
  
  <pre><code>PYTHONPATH="/Users/nicolas/Code:/Users/nicolas/Code/Dashboard"
  export $PYTHONPATH
  </code></pre>
  
  <p>** from the command line **</p>
  
  <p>1] test one</p>
  
  <pre><code>echo $PYTHONPATH
  /Users/nicolas/Code:/Users/nicolas/Code/Dashboard
  </code></pre>
  
  <p><em>appears to work</em></p>
  
  <p>2] test two</p>
  
  <pre><code>`sh -c 'echo "$PYTHONPATH"' `
  ==&gt; empty output
  </code></pre>
  
  <p><em>actually doesnt</em></p>
  
  <p>3] test three</p>
  
  <p>running the folloing python script, with the command <code>python script.py</code></p>
  
  <pre><code>#!/usr/bin/env python
  import os
  try:
      user_paths = os.environ['PYTHONPATH'].split(os.pathsep)
  except KeyError:
      user_paths = 'no pythonpath'
  print user_paths
  </code></pre>
  
  <p>outputs :
      no pythonpath</p>
  
  <p><em>fails again</em></p>
  
  <p>4] test four</p>
  
  <pre><code>zsh -x -c 'echo moo'
  
  +/etc/zshenv:2&gt; [ -x /usr/libexec/path_helper ']'
  +/etc/zshenv:3&gt; /usr/libexec/path_helper -s
  +/etc/zshenv:3&gt; eval 'PATH="/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/local/bin:/opt/X11/bin:/usr/texbin:/Users/nicolas/anaconda/bin:/opt/local/lib/postgresql93/bin:/Users/nicolas/Code/games:/Users/nicolas/Code/Dashboard";' export 'PATH;'
  +(eval):1&gt; PATH=/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/local/bin:/opt/X11/bin:/usr/texbin:/Users/nicolas/anaconda/bin:/opt/local/lib/postgresql93/bin:/Users/nicolas/Code/games:/Users/nicolas/Code/Dashboard
  +(eval):1&gt; export PATH
  +zsh:1&gt; echo moo
  moo
  </code></pre>
  
  <hr>
  
  <p>extra info :</p>
  
  <pre><code>which zsh
  </code></pre>
  
  <p>outputs : /usr/local/bin/zsh</p>
  
  <p>My $PATH is ok, it's perfectly similar from the terminal and from inside python.</p>
  
  <p>What is happening, and how can i solve this ?</p>
  
  <p>Using Mac os, python installed from anaconda</p>