# Your goal in this kata is to implement a difference function,
# which subtracts one list from another and returns the result.
# It should remove all values from list a, which are present in list b keeping their order.
# array_diff([1,2],[1]) == [2]

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

print(array_diff([1,2], [1]))
print(array_diff([1,2,2], [1]))