Returns a percentage difference between two sets of values. Used as a solution for the level 1 google foobar problem

foobar.py

def answer(y, x):
    # Make sure we are always comparing the smaller list to the larger list.
    if (sum(x) > sum(y)):
        y,x = x,y
    # The quotient of each one of the matching elements in an array
    result = [b/a if a else 0 for a,b in zip(sorted(y), sorted(x))]
    # Average percentage of increase, rounded up to one. 
    return int(100 - (sum(result) / float(len(result))) * 100)