How can I compare two lists in python and return not matches

Question

I would like to return values from both lists that not in the other one:

bar = [ 1,2,3,4,5 ]
foo = [ 1,2,3,6 ]

returnNotMatches( a,b )

would r

Answer 1

Just use a list comprehension:

def returnNotMatches(a, b):
    return [[x for x in a if x not in b], [x for x in b if x not in a]]