LIST處理

1. 列表拓展
a = [1, 2, 3, 4, 5]
lenn = len(a)
for i in range(0, len(a)):
    m = [a] * (lenn ** i)
    b = list(chain.from_iterable(zip(*m)))
    b = b*(lenn**(lenn-1-i))
    print(b)

2.排列組合

itertools.combinations