title: os.path.isdir() returns False even when folder exists
body: <p>I'm currently writing a script which has to check if all specified folders actually exist. 
  I found out I have to use os.path.isdir() with absolute paths. </p>
  
  <p>I have the following directory structure:</p>
  
  <pre><code>X:\
    pythonscripts\
      files\
        Films\
        Series\
      src\
  </code></pre>
  
  <p>When I open op my python command line and try if the folders actually exist, I get the following:</p>
  
  <pre><code>&gt;&gt;&gt; import os
  &gt;&gt;&gt; os.path.isdir('X:\pythonscripts\src')
  True
  &gt;&gt;&gt; os.path.isdir('X:\pythonscripts\files')
  False
  &gt;&gt;&gt; os.path.isdir('X:\pythonscripts\files\Films')
  False
  &gt;&gt;&gt; os.path.isdir('X:\pythonscripts\files\Series')
  False
  </code></pre>
  
  <p>Which is odd, because when I copy and paste these paths into Windows Explorer, I can access them without problems. I checked permissions and all folders have the same permissions on them. Does anyone know what I'm doing wrong?</p>