在元组列表中查找元组(按多个键排序) [英] Finding tuple in the list of tuples (sorting by multiple keys)

问题描述

我正在尝试在元组列表中找到元组，但没有获取操作方法

I am trying to find tuple in the list of tuple, but not getting how to do that

我有以下list (id, price, count)

[('1', 3.0, 6), ('2', 2.0, 2), ('3', 2.0, 5), ('4', 4.0, 2), ('5', 2.0, 5), ('
6', 3.0, 6), ('7', 3.0, 5), ('8', 2.0, 5), ('9', 3.0, 5), ('10', 3.0, 5)]

查找元组的条件是:

1. 元组应具有最小的price.
2. 元组的最大计数应为value.
3. 第一个条件的优先级高于第二个条件.

1. tuple should have minimum price.
2. tuple should have maximum count value.
3. priority of first condition is higher then second condition.

请告诉我如何实现这些条件才能在列表中找到元组.

Please tell me how to achieve these conditions to find tuple in the list.

推荐答案

您可以为从列表项的两个元素中排序:(price, -count)(减用来反转方向的计数-较大的值将首先出现):

You can build key for sorted from two elements of your list items: (price, -count) (minus count used to invert direction - bigger value will be first in result):

t = [('1', 3.0, 6), ('2', 2.0, 2), ('3', 2.0, 5), ('4', 4.0, 2), ('5', 2.0, 5),
     ('6', 3.0, 6), ('7', 3.0, 5), ('8', 2.0, 5), ('9', 3.0, 5), ('10', 3.0, 5)]

>>> sorted(t, key=lambda i: (i[1], -i[2]))
[('3', 2.0, 5), ('5', 2.0, 5), ('8', 2.0, 5), ('2', 2.0, 2), ('1', 3.0, 6),
 ('6', 3.0, 6), ('7', 3.0, 5), ('9', 3.0, 5), ('10', 3.0, 5), ('4', 4.0, 2)]

要仅查找一个元素，可以使用具有相同功能的 min 函数元组作为关键参数:

To find only one element you can use min function with same tuple as key argument:

>>> min(t, key=lambda i: (i[1], -i[2]))
('3', 2.0, 5)

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