title: open() can't find file given path relative to PYTHONPATH
body: <p>I did <code>export PYTHONPATH=$PYTHONPATH:/home/User/folder/test</code>. Then I ran python when I was in <code>/home/User/</code> and checked <code>sys.path</code> - it was correct.</p>
  
  <pre><code>&gt;&gt;&gt; import sys
  &gt;&gt;&gt; sys.path
  ['', '/usr/local/lib/python2.7/dist-packages/gitosis-0.2-py2.7.egg', 
  '/home/User', '/home/User/folder/test','/usr/lib/python2.7',
  '/usr/lib/python2.7/plat-linux2', '/usr/lib/python2.7/lib-tk', 
  '/usr/lib/python2.7/lib-old', '/usr/lib/python2.7/lib-dynload', 
  '/usr/local/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages']
  </code></pre>
  
  <p>Then I tried to open a file <code>/home/User/folder/test/pics/text/text.txt</code> like this:</p>
  
  <pre><code>&gt;&gt;&gt;file = open('pics/text/text.txt','r')
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  IOError: [Errno 2] No such file or directory:
  </code></pre>
  
  <p>As you can see, first half of path to file is in <code>$PYTHONPATH</code>, and second half is given as an argument to <code>open()</code> function. Why doesn't it work? What should I change?</p>
  
  <p>When I ran python from <code>/home/User/folder/test</code> (exported path) and tried to open file - it worked.</p>