I want this function to loop through both lists and return the object that is the same in both. : These are the lists; note how the second list is made up of objects that need splitting first.  

    gaps = ['__1__', '__2__', '__3__']
    questions = ['Bruce Wayne is __1__', 'Clark Kent is __2__', 'Barry Allen is __3__']

Here's the code. It seems to work only for the first (zeroth) object, bud that's it - it doesn't even loop.

    def is_gap(question, gap):
	place = 0
	while (place < 3):
		question[place] = question[place].split(' ')
		for index in gaps:
				if index in question[place]:
					return index
				else:
					return None
	place += 1
    print is_gap(questions, gaps)
Please be gentle, I am a complete beginner!