rue``.

        >>> 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, :func:`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, ' '])

    c