title: Access dictionary value when the key is a tuple
body: <p>I'm new to Python and I have a problem where I need to get the value from a dictionary where the keys are tuples. For example:</p>
  
  <pre><code>ones = {(1,2,6,10):3, (4,5,9):4, (3,7,8):5}
  </code></pre>
  
  <p>I know that each number appears ones in the keys, and I want to access the value where the key has the number 2 in (the value will be 3).</p>
  
  <p>Can I get any help on how to access this value?</p>