将Python字典的值替换为与其他字典键匹配的另一个字典的值 [英] Replacing the value of a Python dictionary with the value of another dictionary that matches the other dictionaries key

问题描述

目前我有两个字典

dictionary1 = {'key1': 'value1', 'key2': 'value2', 'key3': 'value3'}
dictionary2 = {'value1': 'AAA', 'value3': 'CCC'}

我想用dictionary2的值替换dictionary1的值，上面的示例将产生以下输出

I want to replace the values of dictionary1 with the values from dictionary2 which with the example above would produce the following output

{'key1': 'AAA', 'key2': 'value2', 'key3': 'CCC'}

在其他示例中，我认为应该以如下方式开始代码:

From other examples I have read I think that I should begin my code as follows:

for key, value in dictionary1.iteritems():
    if value ==

现在，我不确定在另一本字典中循环查找以发现Dictionary1中的值是否与Dictionary2中的键匹配的最佳方法.

Now I am unsure as to the best method to cycle through the other dictionary to find if the value from dictionary1 matches a key from dictionary2.

推荐答案

您可以使用字典理解来做到这一点

You can do this with dictionary comprehension, like this

>>> dictionary1 = {'key1': 'value1', 'key2': 'value2', 'key3': 'value3'}
>>> dictionary2 = {'value1': 'AAA', 'value3': 'CCC'}
>>> {k: dictionary2.get(v, v) for k, v in dictionary1.items()}
{'key3': 'CCC', 'key2': 'value2', 'key1': 'AAA'}

在这里，dict2.get(v, v)将尝试从dict2获取与值v相对应的值.如果找不到，则会返回默认值(第二个参数)v本身.

Here, dict2.get(v, v) will try to get the value corresponding to the value v from dict2. If it is not found, the default value (second parameter), v itself will be returned.

注释1:您所遇到的问题称为字典，而不是列表.

Note 1: What you have in question, are called dictionaries, not lists.

注2::如果您使用的是Python 2.7，则可能要使用dict1.iteritems或dict1.viewitems而不是dict1.items.在此答案中详细举例说明了原因.

Note 2: If you are using Python 2.7, then you might want to use dict1.iteritems or dict1.viewitems instead of dict1.items. The reason is explained, elaborately, with examples, in this answer.

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