from collections import Iterator from collections import Iterable class Classmate(object):     def __init__(self):         self.prev = 0         self.curr = 1     # def add(self, name):     #     ret = self.names.append(name)     #     return ret     def __iter__(self):         return self     def __next__(self):         value = self.curr         self.curr += self.prev         self.prev = value         return value if __name__ == '__main__':     c = Classmate()