按值排序Python字典 [英] Sort a Python dictionary by value

问题描述

我有一个值从数据库中的两个字段读取的值：字符串字段和数字字段。字符串字段是唯一的，所以这是字典的关键。

I have a dictionary of values read from two fields in a database: a string field and a numeric field. The string field is unique, so that is the key of the dictionary.

我可以按键排序，但是如何根据值进行排序？

I can sort on the keys, but how can I sort based on the values?

注意：我已经阅读了Stack Overflow问题如何按照Python中的字典，并且可能会将我的代码更改为具有字典列表，但是由于我真的不需要一个字典列表，我想知道如果有一个更简单的解决方案。

Note: I have read Stack Overflow question How do I sort a list of dictionaries by values of the dictionary in Python? and probably could change my code to have a list of dictionaries, but since I do not really need a list of dictionaries I wanted to know if there is a simpler solution.

推荐答案

不可能对dict进行排序，只能获取排序的dict的表示形式。判决本质上是无序的，但其他类型，如列表和元组，则不是。所以你需要一个排序的表示，这将是一个列表，可能是一个元组列表。

It is not possible to sort a dict, only to get a representation of a dict that is sorted. Dicts are inherently orderless, but other types, such as lists and tuples, are not. So you need a sorted representation, which will be a list—probably a list of tuples.

例如，

import operator
x = {1: 2, 3: 4, 4: 3, 2: 1, 0: 0}
sorted_x = sorted(x.items(), key=operator.itemgetter(1))

sorted_x 将是每个元组中第二个元素排序的元组列表。 dict（sorted_x）== x 。

对于那些希望按键而不是值进行排序的人： p>

And for those wishing to sort on keys instead of values:

import operator
x = {1: 2, 3: 4, 4: 3, 2: 1, 0: 0}
sorted_x = sorted(x.items(), key=operator.itemgetter(0))

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