I want to do something similar to this:
>>> x = [1,2,3,4,5,6,7,8,9,0] >>> x [1, 2, 3, 4, 5, 6, 7, 8, 9, 0] >>> y = [1,3,5,7,9] >>> y [1, 3, 5, 7, 9] >>> y - x # (should return [2,4,6,8,0])
But this is not supported by python lists What is the best way of doing it?
Use a list comprehension:
[item for item in x if item not in y]
If you want to use the
- infix syntax, you can just do:
class MyList(list): def __init__(self, *args): super(MyList, self).__init__(args) def __sub__(self, other): return self.__class__(*[item for item in self if item not in other])
you can then use it like:
x = MyList(1, 2, 3, 4) y = MyList(2, 5, 2) z = x - y
But if you don't absolutely need list properties (for example, ordering), just use sets as the other answers recommend.