title: How to manipulate dictionary with tuple keys to output pandas dataframe
body: <p>Say I have a dictionary that looks like:</p>
  
  <pre><code>{('a','1'):2,
   ('a','2'):1,
   ('b','1'):3,
   ('b','2'):2}
  </code></pre>
  
  <p>I want to get a dataframe result that takes the highest value item for the first key ('a','b' in this case) and create a dataframe from the tuple key.</p>
  
  <pre><code>key    value
  'a'      '1'
  'b'      '1'
  </code></pre>
  
  <p>How can I do this in python?</p>