python 迭代器

from collections import Iterator

class IterA(Iterator):

    def __init__(self,Itlist):

        self.Itlist = Itlist
        self.index = 0

    def next(self):
        if self.index == len(self.Itlist):
            raise StopIteration
        a = self.Itlist[self.index]
       
        self.index +=1
        return a