In [22]: lst = [[1,2,3],[1,2],[1,2,3],[2,3],[4,5],[2,3],[2,4],[4,2]] In [23]: set(frozenset(item) for item in lst) Out[23]: set([frozenset([2, 4]), frozenset([1, 2]), frozenset([2, 3]), frozenset([1, 2, 3]), frozenset([4, 5])])