开满天机
在python 2.7和3.1中有一个itertools.combinations_with_replacement功能:>>> list(itertools.combinations_with_replacement([1, 2, 3, 4, 5, 6], 2))[(1, 1), (1, 2), (1, 3), (1, 4), (1, 5), (1, 6), (2, 2), (2, 3), (2, 4), (2, 5), (2, 6), (3, 3), (3, 4), (3, 5), (3, 6), (4, 4), (4, 5), (4, 6), (5, 5), (5, 6), (6, 6)]