itercools.py 文件源码

def partition(iterable, predicate):
    """Divide the iterable into two iterables according to the predicate.

    >>> evens, odds = partition(range(10), lambda x: not x % 2)
    >>> list(evens)
    [0, 2, 4, 6, 8]
    >>> list(odds)
    [1, 3, 5, 7, 9]
    """
    t1, t2 = tee(iterable)
    return filter(predicate, t1), filterfalse(predicate, t2)