Python:从zip附加到字典 [英] Python: Append to dictionary from a zip

问题描述

可以说我有以下列表，例如[key,value, key,value, key,value] 我想把它变成字典，看起来像: {key:value, key:value, key:value}

Lets say I have the following list such as [key,value, key,value, key,value] and I want to turn it into a dictionary which looks like: {key:value, key:value, key:value}

我尝试过

dict(zip(mydict[::2], mydict[1::2]))

但是，其中一个键的原始值一直被覆盖.如果键已经存在，如何更改它以便附加到字典中?

However, the original values for one of the keys keeps being overwritten. How can I change this so it appends to the dictionary if the key already exists?

推荐答案

我不确定我是否会误会.字典中不能有重复的键.一个将覆盖另一个.

I'm not sure if I'm misunderstanding then. You cannot have repeated keys inside a dictionary. One will overwrite the other.

 [in] >>> d = dict([('x',3),('x',4)])
 [in] >>> print(d)
[out] >>> {'x': 4}

也许您正在考虑使用defaultdict

Maybe you're thinking of a defaultdict

 [in] >>> from collections import defaultdict
 [in] >>> d = defaultdict(list)
 [in] >>> for k,v in [('x',3),('x',4)]:
      >>>     d[k].append(v)
 [in] >>> print(d)
[out] >>> defaultdict(<class 'list'>, {'x': [3, 4]})

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