1、yield由于创建迭代器

def deal():
    tmp = []
    for i in range(20):
        tmp.append(i)
        if i % 4 == 0:
            yield tmp
            tmp = []
    yield tmp　　 #S1
    return tmp   #S2

for dd in deal():
    print(dd)
exit()

输出：

# S1

[0]
[1, 2, 3, 4]
[5, 6, 7, 8]
[9, 10, 11, 12]
[13, 14, 15, 16]
[17, 18, 19]

# S2

[0]
[1, 2, 3, 4]
[5, 6, 7, 8]
[9, 10, 11, 12]
[13, 14, 15, 16]