title: What is the difference between common_funny and funny_files from filecmp.dircmp?
body: <p>The filecmp module from the standard library contains a the <a href="http://docs.python.org/py3k/library/filecmp.html#the-dircmp-class" rel="nofollow">dircmp class</a> which has two similar sounding attribues:</p>
  
  <p><strong>common_funny:</strong></p>
  
  <blockquote>
    <p>Names in both a and b, such that the type differs between the
    directories, or names for which os.stat() reports an error.</p>
  </blockquote>
  
  <p><strong>funny_files:</strong></p>
  
  <blockquote>
    <p>Files which are in both a and b, but could not be compared.</p>
  </blockquote>
  
  <p>What would cause files or directories to appear in common_funny?
  What would cause files or directories to appear in funny_files?</p>