使用两个键对 Python 列表进行排序，但只有一个以相反的顺序 [英] sort Python list with two keys but only one in reverse order

问题描述

我想知道通过两个键对元组列表进行排序的 Pythonic 方式是什么，其中使用一个(并且只有一个)键进行排序是相反的顺序，而使用另一个键进行排序将不区分大小写.更具体地说，我有一个包含元组的列表，例如:

I was wondering what would be a Pythonic way of sorting a list of tuples by two keys whereby sorting with one (and only one) key would be in a reverse order and sorting with the the other would be case insensitive. More specifically, I have a list containing tuples like:

myList = [(ele1A, ele2A),(ele1B, ele2B),(ele1C, ele2C)]

我可以用下面的代码用两个键对它进行排序:

I can use the following code to sort it with two keys:

sortedList = sorted(myList, key = lambda y: (y[0].lower(), y[1]))

要以相反的顺序排序，我可以使用

To sort in reverse order I can use

sortedList = sorted(myList, key = lambda y: (y[0].lower(), y[1]), reverse = True)

但这会用两个键以相反的顺序排序.

but this would sort in a reverse order with two keys.

推荐答案

当我们需要对具有两个约束的列表进行排序时，将使用两个键，一个是升序，另一个是降序在同一个列表中或任意
在您的示例中
sortedList = sorted(myList, key = lambda y: (y[0].lower(), y[1])) 只能对整个列表进行排序命令
您可以尝试这些并检查发生了什么

Two keys will be used when we need to sort a list with two constraints one in ascending order and other in descending in the same list or any
In your example
sortedList = sorted(myList, key = lambda y: (y[0].lower(), y[1])) can sort entire list only in one order
you can try these and check whats happening

sortedList = sorted(myList, key = lambda y: (y[0].lower(), -y[1]))
sortedList = sorted(myList, key = lambda y: (-y[0].lower(), y[1]))
sortedList = sorted(myList, key = lambda y: (-y[0].lower(), -y[1]))

希望你在这之后会明白;)

hope you will understand after this ;)

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