是否有用于Python 3.x的array_diff（php）方法模拟

Question

例如：

>> a = list(["red", "blue", "red"]);
>> b = list(["yellow", "red"]);

array_diff的结果：

>> list("blue")

或最好的方法吗？

Answer 1

将它们转换为集合并进行集合减法

>>> a = ["red", "blue", "red"]
>>> b = ["yellow", "red"]
>>> set(a) - set(b)
{'blue'}
>>> a
['red', 'blue', 'red'] # the lists are still the same