如果字典键不可用，则不返回任何值 [英] Return None if Dictionary key is not available

问题描述

我需要一种方法来获取字典值(如果它的键存在)，或者简单地返回None(如果它不存在).

I need a way to get a dictionary value if its key exists, or simply return None, if it does not.

但是，如果您搜索不存在的键，Python会引发KeyError异常.我知道我可以检查密钥，但是我正在寻找更明确的密钥.如果密钥不存在，有没有办法只返回None?

However, Python raises a KeyError exception if you search for a key that does not exist. I know that I can check for the key, but I am looking for something more explicit. Is there a way to just return None if the key does not exist?

推荐答案

您可以使用 dict.get()

You can use dict.get()

value = d.get(key)

，如果key is not in d，则将返回None.您还可以提供其他默认值，而不是None:

which will return None if key is not in d. You can also provide a different default value that will be returned instead of None:

value = d.get(key, "empty")

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