在 Python 中使用 zip 函数对 2 个相关的列表进行排序，如何按降序排序

Question

所以，我正在尝试对 2 个相关列表进行排序。一个包含候选人姓名，另一个包含候选人拥有的票数(candidate[0]中的候选人的选票存储在votes[0]中(。

我找到了一种按降序对 vote[] 进行排序的方法，同时保持索引匹配。例如，如果vote[0]变成vote[3]，candidate[0]也会变成candidate[3]。我使用内置的 zip 函数执行此操作，但我从中复制的示例按升序对列表进行排序，而我要求它们按降序排序。以下是我的清单：

candidates = ['Donald', 'Barack', 'Hillary', 'Mitt']
votes = [9, 7, 1, 3]

并对我使用的列表进行排序：

votes, candidates = (list(t) for t in zip(*sorted(zip(votes, candidates))))

这完全符合我的意愿，除了升序，而不是降序。如何编辑它以将列表按降序排序？

Answer 1

您可以

对list的zip进行排序并对其进行reverse

>>> votes = [9, 7, 1, 3]
>>> candidates = ['Donald', 'Barack', 'Hillary', 'Mitt']
>>> 
>>> sorted(zip(votes, candidates), key=lambda x: x[0]) # in ascending order
[(1, 'Hillary'), (3, 'Mitt'), (7, 'Barack'), (9, 'Donald')]
>>>
>>> sorted(zip(votes, candidates), key=lambda x: x[0], reverse=True) # in descending order
[(9, 'Donald'), (7, 'Barack'), (3, 'Mitt'), (1, 'Hillary')]
>>> # and if you want it back in order again;
>>> votes, names = zip(*sorted(zip(votes, candidates), key=lambda x: x[0], reverse=True))
>>> votes
(9, 7, 3, 1)
>>> names
('Donald', 'Barack', 'Mitt', 'Hillary')

Answer 2

使用 reverse=True ：

candidates = ['Donald', 'Barack', 'Hillary', 'Mitt']
votes = [9, 7, 1, 3]
votes, candidates = (list(t) for t in zip(*sorted(zip(votes, candidates))))

print(sorted(votes, reverse=True))
print(sorted(candidates, reverse=True))

输出：

[9, 7, 3, 1]
['Mitt', 'Hillary', 'Donald', 'Barack']

或

candidates = ['Donald', 'Barack', 'Hillary', 'Mitt']
votes = [9, 7, 1, 3]
print(sorted(zip(candidates, votes), reverse=True))

输出：

[('Mitt', 3), ('Hillary', 1), ('Donald', 9), ('Barack', 7)]

编辑3：

candidates = ['Donald', 'Barack', 'Hillary', 'Mitt']
votes = [9, 7, 1, 3]
votes, candidates = (list(t) for t in zip(*sorted(zip(votes, candidates), reverse=True)))
print(votes)
print(candidates)

输出：

[9, 7, 3, 1]
['Donald', 'Barack', 'Mitt', 'Hillary']

Answer 3

或者，用于反转的切片：

candidates = ['Donald', 'Barack', 'Hillary', 'Mitt']
votes = [9, 7, 1, 3]
votes, candidates = (list(t) for t in zip(*sorted(zip(votes, candidates))[::-1]))