title: Try/Except error when using 'None'
body: <p>I have a bit of code that isn't behaving as expected. 
  I've condensed it down to the problem here:</p>
  
  <pre><code>item = None
  
  try:
      if item != None:
          print('pass')
  except TypeError, e:
      print('fail')
  </code></pre>
  
  <p>if item is something other than 'None' type it prints pass. I wanted raise an exception 
  if the item is None but when I set item to None nothing prints out.</p>
  
  <p>I could easily do this with an if statement but I'm curious to know why this isn't working as an try/except.</p>
  
  <p>any thoughts?</p>
  
  <p>Thanks!</p>