title: How I can get rid of None values in dictionary?
body: <p>Something like:</p>
  
  <pre><code>for (a,b) in kwargs.iteritems():
      if not b : del kwargs[a]
  </code></pre>
  
  <p>This code raise exception because changing of dictionary when iterating.</p>
  
  <p>I discover only non pretty solution with another dictionary:</p>
  
  <pre><code>res ={}
  res.update((a,b) for a,b in kwargs.iteritems() if b is not None)
  </code></pre>
  
  <p>Thanks</p>