title: looking for the appropriate python data structure
body: <p>I'm looking for a python 2.7 data structure equivalent to a dictionary but where I can associate more than 1 key.</p>
  
  <p>For example I want to associate:</p>
  
  <ul>
  <li>cars:
  -Chevrolet
  -Toyota
  -hummer
  -Ferrari</li>
  <li>computer:
  -mac
  -windows
  -linux
  -amstrad</li>
  </ul>
  
  <p>I need to be able to search in the dictionary for the string 'cars' or 'computers' or others using something like <code>myDictionary.has('cars')</code></p>
  
  <p>and loop through all the keys corresponding to cars using <code>for key in myDictionary:</code></p>