python 列表的排列组合

• 2019 年 10 月 11 日
• 筆記

permutations/combinations/combinations_with_replacement

   items = ['a', 'b', 'c']   from itertools import permutations   for p in permutations(items):   ...     print(p)   ...   ('a', 'b', 'c')   ('a', 'c', 'b')   ('b', 'a', 'c')   ('b', 'c', 'a')   ('c', 'a', 'b')   ('c', 'b', 'a')           for p in permutations(items, 2):   ...     print(p)   ...   ('a', 'b')   ('a', 'c')   ('b', 'a')   ('b', 'c')   ('c', 'a')   ('c', 'b')           from itertools import combinations   for c in combinations(items, 3):   ...     print(c)   ...   ('a', 'b', 'c')           for c in combinations(items, 2):   ...     print(c)   ...   ('a', 'b')   ('a', 'c')   ('b', 'c')           for c in combinations(items, 1):   ...     print(c)   ...   ('a',)   ('b',)   ('c',)           for c in combinations_with_replacement(items, 3):   ...     print(c)   ...   ('a', 'a', 'a')   ('a', 'a', 'b')   ('a', 'a', 'c')   ('a', 'b', 'b')   ('a', 'b', 'c')   ('a', 'c', 'c')   ('b', 'b', 'b')   ('b', 'b', 'c')   ('b', 'c', 'c')   ('c', 'c', 'c')