如何从元组(或2个列表)更新字典 [英] How to update dictionary from a tuple (or list of 2)

问题描述

我认为可以如下更新现有字典:

I thought it would be possible to update an existing dictionary as follows:

nameValuePair = 'myKey=myValue'
d.update(nameValuePair.split('='))

但是我收到此错误:

Traceback (most recent call last):
  File "<pyshell#98>", line 1, in <module>
    d2.update(item.split('='))
ValueError: dictionary update sequence element #0 has length 1; 2 is required

我查看了有关此主题的其他StackOverflow问题/答案，这使我认为这是可能的.我一定缺少基本的东西...

I looked at some other StackOverflow questions/answers on this topic, which made me think this was possible. I must be missing something basic...

推荐答案

该错误消息已经为您提供了提示:您传递的序列中的每个项目的长度都必须为2，这意味着它必须包含一个键和一个值.

The error message already gives you a hint: Each item in the sequence you pass must have a length of 2, meaning it has to consist of a key and a value.

因此，您必须传递2个元组(-lists，-sequences等)的元组(list，sequence ...):

Therefore you have to pass a tuple (list, sequence,...) of 2-tuples (-lists, -sequences,...):

// the value passed will be ((myKey, myValue), )
d.update((nameValuePair.split('='), ))
//       ^                        ^ ^
// creates a tuple of 1 element

或者，您可以执行以下操作:

Alternatively you could do:

key, value = nameValuePair.split('=')
d[key] = value

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