Python 求列表的所有 k 阶排列

Python 求列表的所有 k 阶排列

既然谈到排列，当然要和组合的结果对比一下才更直观，更有意思！！！

组合

import itertools

input_list = [1, 2, 4]
k = 2
print(list(itertools.combinations(input_list, k)))

k = 3
print(list(itertools.combinations(input_list, k)))

[(1, 2), (1, 4), (2, 4)]
[(1, 2, 4)]

排列 

import itertools

input_list = [1, 2, 4]
k = 2
print(list(itertools.permutations(input_list, k)))

k = 3
print(list(itertools.permutations(input_list, k)))

[(1, 2), (1, 4), (2, 1), (2, 4), (4, 1), (4, 2)]
[(1, 2, 4), (1, 4, 2), (2, 1, 4), (2, 4, 1), (4, 1, 2), (4, 2, 1)]