python简单循环生成器

import time

#循环生成器
def traversal_list(alist, i):
    while True:
        length = len(alist)
        i = i%(length)
        yield alist[i]
        i += 1

def traversal_list2(alist):
    i = 0
    f = traversal_list(alist, i)
    while True:
        a = next(f)
        print(a)
        time.sleep(1)
        i += 1

if __name__ == '__main__':
    alist = [1, 2, 3, 4, 5]
    traversal_list2(alist)