马哥 今日小技巧 itertools生成排列 有大用

# itertools生成排列

# itertools.permutations() generates permutations 

# for an iterable. Time to brute-force those passwords ;-)

>>> import itertools

>>> for p in itertools.permutations('ABCD'):

...     print(p)

('A', 'B', 'C', 'D')

('A', 'B', 'D', 'C')

('A', 'C', 'B', 'D')

('A', 'C', 'D', 'B')

('A', 'D', 'B', 'C')

('A', 'D', 'C', 'B')

('B', 'A', 'C', 'D')

('B', 'A', 'D', 'C')

('B', 'C', 'A', 'D')

('B', 'C', 'D', 'A')

('B', 'D', 'A', 'C')

('B', 'D', 'C', 'A')

('C', 'A', 'B', 'D')

('C', 'A', 'D', 'B')

('C', 'B', 'A', 'D')

('C', 'B', 'D', 'A')

('C', 'D', 'A', 'B')

('C', 'D', 'B', 'A')

('D', 'A', 'B', 'C')

('D', 'A', 'C', 'B')

('D', 'B', 'A', 'C')

('D', 'B', 'C', 'A')

('D', 'C', 'A', 'B')

('D', 'C', 'B', 'A')