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)