从 python 列表中获取元素的唯一组合

Get unique combinations of elements from a python list

提问by Allen

Edit: This is not a exact duplicate of How to get all possible combinations of a list's elements?

编辑：这不是如何获得列表元素的所有可能组合的完全重复？

This topic is about finding unique combinations while the other topic is about finding ALL combinations.

本主题是关于查找唯一组合，而另一个主题是关于查找所有组合。

If I have a python list:

如果我有一个 python 列表：

 L = [1,2,3,4]

what's the best way to get all the possible unique combinationsof 3 elements from the list like below:

从列表中获取3 个元素的所有可能的唯一组合的最佳方法是什么：

["1,2,3", "1,2,4", "2,3,4", "3,4,1"]

The order of the elements in the combinations doesn't matter. For example, "1,2,3"and "3,2,1"will be considered the same combination.

组合中元素的顺序无关紧要。例如，"1,2,3"和"3,2,1"将被视为相同的组合。

I can probably write a few loops to do this but I think there might be a one-liner which can do the same.

我可能会写几个循环来做到这一点，但我认为可能有一个单线可以做到这一点。

采纳答案by Ashwini Chaudhary

You need itertools.combinations:

你需要itertools.combinations：

>>> from itertools import combinations
>>> L = [1, 2, 3, 4]
>>> [",".join(map(str, comb)) for comb in combinations(L, 3)]
['1,2,3', '1,2,4', '1,3,4', '2,3,4']