title: Checking a key exists or not in a dictionary
body: <p>I have a dictionary like this</p>
  
  <pre><code>odict([(1, {'media_one': '000121'}), (2, {'media_two': '201984'}), (3, {'media_three': '301984'})])
  </code></pre>
  
  <p>I want to check if the key media_two or media_one or media_three is exists in this dictionary or not. If exists do something else do nothing.
  How can we check</p>