python阅读程序

这个程序的结果为什么是36啊，怎么去看呢，里面有什么知识点呢

你可以多打印几次

a = [[1] * 3, [2] * 3, [3] * 3]
print(a)  # [[1, 1, 1], [2, 2, 2], [3, 3, 3]]
b = [1, 2, 3]
s = 0
for c in a:
    for j in range(3):
        s += c[j] * b[j]
        print(s)
print(s)