迭代器和可迭代对象

Posted 2021-01-25 zhoulixiansen

from collections.abc import Iterator


class Company(object):
    def __init__(self, employee_list):
        self.employee = employee_list

    def __iter__(self):  # 一般情况下都是这个样做
        return MyIterator(self.employee)

    # def __getitem__(self, item):
    #     return self.employee[item]


class MyIterator(Iterator):
    def __init__(self, employee_list):
        self.iter_list = employee_list
        self.index = 0

    def __next__(self):
        # 真正返回迭代值的逻辑
        try:
            word = self.iter_list[self.index]
        except IndexError:
            raise StopIteration  # 只有抛出这个异常for循环才能捕获到
        self.index += 1
        return word


if __name__ == "__main__":
    company = Company(["tom", "bob", "jane"])
    my_itor = iter(company)
    # while True:
    #     try:
    #         print (next(my_itor))
    #     except StopIteration:
    #         pass

    # next(my_itor)
    for item in company:
        print(item)

为啥不在可迭代对象写迭代器呢？这个是一个编程规范