如何在字典中的特定键之间交换值？(How to exchange values between specific keys in a dictionary?)

如何在字典中的特定键之间交换值？(How to exchange values between specific keys in a dictionary?)

假设你有这样一本字典：

d = { 'A': 'content_for_A', 'B': 'content_for_B' }

在两个条目之间交换值的最有效方法是什么？ 所以结果应该是这样的：

d = { 'A': 'content_for_B', 'B': 'content_for_A' }

当然，你可以创建一个新的字典d2并做d2['A'] = d['B']; d2['B'] = d['A'] d2['A'] = d['B']; d2['B'] = d['A']但这是推荐的方式还是有效的方式，而不需要创建一个新的字典？

Let's say you have a dictionary like this:

d = { 'A': 'content_for_A', 'B': 'content_for_B' }

What is the most efficient way to swap the values between the two entries? So the result should be like this:

d = { 'A': 'content_for_B', 'B': 'content_for_A' }

Of course, you can create a new dictionary d2 and do d2['A'] = d['B']; d2['B'] = d['A'] but is this the recommended way or is there an efficient way without the need to create a new dictionary?

最满意答案

d['A'], d['B'] = d['B'], d['A']

在Python中，Tuple解包是一个很好的工具，可以在不需要创建中间变量的情况下交换两个对象的值。

d['A'], d['B'] = d['B'], d['A']

Tuple unpacking is a great tool in Python to swap the values of two objects without the need of creating an intermediary variable.