kyu6_array_diff.py

""" 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;
If a value is present in b, all of its occurrences must be removed from the other;

Examples:
    array_diff([1,2],[1]) == [2]
    array_diff([1,2,2,2,3],[2]) == [1,3]

"""


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