title: Sort Counter by frequency, then alphabetically in Python
body: <p>I am trying to use counter to sort letters by occurrence, and put any that have the same frequency into alphabetical order, but I can't get access to the Value of the dictionary that it produces. </p>
  
  <pre><code>letter_count = collections.Counter("alphabet")
  print(letter_count)
  </code></pre>
  
  <p>produces:</p>
  
  <pre><code>Counter({'a': 2, 'l': 1, 't': 1, 'p': 1, 'h': 1, 'e': 1, 'b': 1})
  </code></pre>
  
  <p>How can I get it ordered by frequency, then by alphabetical order, so everything that shows up only once is in alphabetical order?</p>