title: Counter to List
body: <p>I have a counter like this :</p>
  
  <pre><code>counter = Counter(['a','a','b','b','b','c'])
  </code></pre>
  
  <p>which gives this object :</p>
  
  <pre><code>Counter({'b': 3, 'a': 2, 'c': 1})
  </code></pre>
  
  <p>and from that I want to creat a list such as :</p>
  
  <pre><code>list[0] = 'b'
  list[1] = 'a'
  list[2] = 'c'
  </code></pre>
  
  <p>any idea to do that the simpliest and fastest way possible please ? thanks</p>