title: How can I use chain for X number of dictionaries?
body: <p>I'm trying to sum a number of dictionaries with identical keys to create a sum.  I found the solution for 2 dictionaries here: </p>
  
  <p><a href="https://stackoverflow.com/questions/38987/how-can-i-merge-union-two-python-dictionaries-in-a-single-expression#comment10444947_38990">How to merge two Python dictionaries in a single expression?</a></p>
  
  <p>How can I expand this to account for N number of dictionaries to chain? </p>
  
  <pre><code>    dictionary = {1:{'a':4,'b':10},0:{'a':2,'b':55}, ... N:{'a':10,'b':11}}
      for k, v in itertools.chain(dictionary[0].items(), dictionary[1].items() ...):
          c[k] += v   
  </code></pre>