+def powerset(lst: Sequence[Any]) -> Iterator[Sequence[Any]]:
+ """Returns the powerset of the items in the input sequence.
+
+ >>> for x in powerset([1, 2, 3]):
+ ... print(x)
+ ()
+ (1,)
+ (2,)
+ (3,)
+ (1, 2)
+ (1, 3)
+ (2, 3)
+ (1, 2, 3)
+ """
+ return chain.from_iterable(combinations(lst, r) for r in range(len(lst) + 1))
+
+