Python: See if one set contains another entirely?

Question

Is there a fast way to check if one set entirely contains another?

Something like:

>>>[1, 2, 3].containsAll([2, 1]) True  >>>[1, 2, 3].containsAll([3, 5, 9]) False 

Answer 1

Those are lists, but if you really mean sets you can use the issubset method.

>>> s = set([1,2,3]) >>> t = set([1,2]) >>> t.issubset(s) True >>> s.issuperset(t) True 

For a list, you will not be able to do better than checking each element.

Answer 2

For completeness: this is equivalent to issubset (although arguably a bit less explicit/readable):

>>> set([1,2,3]) >= set([2,1]) True >>> set([1,2,3]) >= set([3,5,9]) False