title: How to construct a defaultdict from a dictionary?
body: <p>If I have <code>d=dict(zip(range(1,10),range(50,61)))</code> how can I build a <code>collections.defaultdict</code> out of the <code>dict</code>? </p>
  
  <p>The only argument <code>defaultdict</code> seems to take is the factory function, will I have to initialize and then go through the original <code>d</code> and update the <code>defaultdict</code>?</p>