30-seconds-of-code/snippets/powerset.md

title, tags

title	tags
powerset	math,list,advanced

Returns the powerset of a given iterable.

• Use the list() constructor to convert the given value to a list.
• Use range() and combinations() to create a generator the returns all subsets.
• Use chain.from_iterable() and the list() constructor to consume the generator and return a list.

from itertools import chain, combinations

def powerset(iterable):
  s = list(iterable)
  return list(chain.from_iterable(combinations(s, r) for r in range(len(s)+1)))

powerset([1, 2]) # [(), (1,), (2,), (1, 2)]