title: OSError's filename attribute unavailable?
body: <p>I have the following code:</p>
  
  <pre><code>except(OSError) as (errno, strerror, filename):
  print "OSError [%d]: %s at %s" % (errno, strerror, filename)
  </code></pre>
  
  <p>It runs great unless it meets OSError num. 123 (<code>The file name, directory name, or volume label syntax is incorrect</code>). then I get the following error at the except code line:</p>
  
  <pre><code>ValueError: need more than 2 values to unpack
  </code></pre>
  
  <p>It is solved by not using the <code>filename</code> attribute. However my requirements prevent me from not using this attribute.</p>
  
  <p>Is there another way?</p>