libb.partition

partition(pred, iterable)

Returns a 2-tuple of iterables derived from the input iterable. The first yields the items that have pred(item) == False. The second yields the items that have pred(item) == True.

>>> is_odd = lambda x: x % 2 != 0
>>> iterable = range(10)
>>> even_items, odd_items = partition(is_odd, iterable)
>>> list(even_items), list(odd_items)
([0, 2, 4, 6, 8], [1, 3, 5, 7, 9])

If pred is None, bool() is used.

>>> iterable = [0, 1, False, True, '', ' ']
>>> false_items, true_items = partition(None, iterable)
>>> list(false_items), list(true_items)
([0, False, ''], [1, True, ' '])