title: Return a tuple of arguments to be fed to string.format()
body: <p>Currently, I'm trying to get a method in Python to return a list of zero, one, or two strings to plug into a string formatter, and then pass them to the string method. My code looks something like this:</p>
  
  <pre><code>class PairEvaluator(HandEvaluator):
    def returnArbitrary(self):
      return ('ace', 'king')
  
  pe = PairEvaluator()
  cards = pe.returnArbitrary()
  print('Two pair, {0}s and {1}s'.format(cards))
  </code></pre>
  
  <p>When I try to run this code, the compiler gives an IndexError: tuple index out of range.<br>
  How should I structure my return value to pass it as an argument to <code>.format()</code>?</p>