title: How to use Counter in python without showing numbers
body: <p>I have little problem with python's Counter library. Here is an example:</p>
  <pre><code>from collections import Counter
  list1 = ['x','y','z','x','x','x','y', 'z']
  print(Counter(list1))
  </code></pre>
  <p>Output of it:</p>
  <pre><code>Counter({'x': 4, 'y': 2, 'z': 2})
  </code></pre>
  <p>My question is how to receive the output without quantity of repetitions?</p>
  <p>What I want to get is:</p>
  <pre><code>Counter('x', 'y', 'z')
  </code></pre>