test_itertools.py 文件源码

def data_deal_function():
    # compress()????????????.????????????????,??????????????.
    # ????????????????True?????
    # ??,????????????.???????Python??????????,??????
    # itertools.filterfalse()???????????,??????.???????????False???True???
    for item in it.compress([1, 2, 3, 4, 5], [False, True, False, 0, 1]):
        print(item)

    # dropwhile()?takewhile()?????????????.??????????????????????????,???????????????.
    # dropwhile()??????????????????????False.?takewhile()??????????False
    # ??,????????????????????????(??dropwhile????,????????????,?takewhile?????????)
    def __single_digit(n):
        return n < 10

    for n in it.dropwhile(__single_digit, range(20)):
        print(n, end=" ")
    for n in it.takewhile(__single_digit, range(20)):
        print(n, end=" ")

    # accumulate()?????????????????????????????(??????,????????????).??,???????
    # [1,2,3,4]??,???result1?1.?????????result1?2??result2,????.????????functools???reduce()????
    for n in it.accumulate([1, 2, 3, 4, ]):
        print(n, end=" ")