用dict值中的相应值替换键引用 [英] Replace key references by corresponding values in dict values

问题描述

在下面的词典中，用户可以将键作为变量来定义另一个值:

In the following dictionary, a user can refer to a key as a variable for defining another value:

d = {'a_key': 'a_value', 'b_key': 'a_key+1'}

为了获得所需的输出，我必须用相应的值替换这些引用:

I have to replace these references by the corresponding values, in order to obtain this desired output:

d = {'a_key': 'a_value', 'b_key': 'a_value+1'}

我以为这很容易，但是几个小时后，这个疯子就疯了.我得到了这段代码:

I thought it would be easy, but this one drives crazy since a few hours. I got to this code:

for k in d.keys():
    print("key: " + k)
    print("value: " + d[k])
    for v in d.values():
        print("value_before: " + v)
        v = v.replace(k, d[k])
        print("value_after: " + v)
print(d)

输出为:

key: a_key
value: a_value
value_before: a_value
value_after: a_value
value_before: a_key+1
value_after: a_value+1
key: b_key
value: a_key+1        # WHY??
value_before: a_value
value_after: a_value
value_before: a_key+1
value_after: a_key+1
{'a_key': 'a_value', 'b_key': 'a_key+1'}

如我们所见，第一次迭代似乎可以完成工作，然后被第二次迭代取消.我只是不明白为什么.我还尝试针对该问题调整非常具体的答案:

As we see, the first iteration seems to do the job, before it is cancelled by the second one. I just don't unserstand why. I also tried to adapt the very specific answers to that question: Replace values in dict if value of another key within a nested dict is found in value, but to no avail. I'm looking for a general answer to: how to get the desired output?

从理论上讲，我还想了解为什么将"b_value" 重置为 a_key + 1 .谢谢.

From a theoretic point of view, I would also like to understand why the "b_value" is reset to a_key+1. Thanks.

推荐答案

问题是您正在修改临时变量 v ，但没有将修改后的值放回字典中.

The problem is that you are modifying temporary variable v but you are not placing the modified values back in the dictionary.

尝试替换:

for v in d.values():
    v = v.replace(k, d[k])

具有:

for r,v in d.items():
    d[r] = v.replace(k, d[k])

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