data_analysis_itertools.py 文件源码

def main():
    # ????????????
    # ??accumulate()????????????,????islice()?????????len(items)-2?????None????????
    for n in itertools.islice(itertools.accumulate(cost(item) for item in items[1:]), len(items) - 2, None):
        print(n)

    # ?????????????
    print(n / (len(items) - 1))

    # ?????????
    owners = {}
    for ky, grp in itertools.groupby(sorted(items[1:], key=owner), key=owner):
        owners[ky] = len(list(grp))
    for member in members[1:]:
        print(member[1], " : ", owners[member[0]])

    # ??????returned()???,???????????????.???filterfalse()??????,???????????????,????????????
    print([items[int(loan[1])] for loan in itertools.filterfalse(returned, loans)])