Dealing with multiple sets

[Tim Peters]

[John Henry]
> If I have a bunch of sets:
>
> a = set((1, 2, 3))
> b = set((2, 3))
> c = set((1, 3))
> ....
>
> What's the cleanest way to say:
>
> 1) Give me a list of the items that are in all of the sets? (3 in the
> above example)

list(a & b & c)

> 2) Give me a list of the items that are not in all of the sets? (1,2 in
> the above example)

list((a | b | c) - (a & b & c))