title: How to check if tuple key contains an element in dictionary
body: <p>I am looking for an operation that could do something similar to this:</p>
  <pre><code>dict[ ( tuple[0] , _ ) ]
  </code></pre>
  <p>The dictionary contains tuples as keys.</p>
  <p>How do I check if the dictionary contains a value where the tuple key has a specific value as the first part and any value as the second part?</p>