Python:使用特定条件对嵌套列表进行排序 [英] Python: Sort a Nested List With Specific Criteria

问题描述

作为Python的初学者，我最近陷入了一个使用特定条件对嵌套列表进行排序的问题.我有一个这样的嵌套列表:

As a beginner of Python I recently get stuck for a problem of sorting a nested list with specific criteria. I have a nested list like this:

nestedList=[['R2D2','1path1','1path2'], 
            ['R3A1','2path1','2path2'],
            ['R15L2','3path1','3path2']]

我希望此列表按每个嵌套列表中的第一个字符串排序.结果如下:

I would like this list to be sorted by the first string in each nested list. The result would look like:

nestedList=[['R15L2','3path1','3path2'],
            ['R3A1','2paht1','2path2'],
            ['R2D2','1path1','1path2']]

目前，我的解决方案仅使用带有反向参数的排序功能:

Currently my solution is only use the sort function with reverse parameter:

nestedList.sort(reverse=True)

我不确定这是否安全，因为我希望它也不按第二个字符串对列表进行排序.

I am not sure whether this is safe, because I would like it not sort the list also by the second string.

如何仅按第一个字符串对其进行排序? (例如"R15L2"，"R3A1"等)

How could I sort it only by the first string? (e.g. 'R15L2', 'R3A1', etc.)

非常感谢您的帮助！

推荐答案

您要根据键(键是列表的第一个元素)进行排序:

You want to sort according to a key (the key is the first element of a list):

nestedList.sort(key=lambda x: x[0])

或

import operator as op

nestedList.sort(key=op.itemgetter(0))

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