在python中确定变量的类型是NoneType
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Determining a variable's type is NoneType in python
提问by splinter
I would like to check if a variable is of the NoneTypetype. For other types we can do stuff like:
我想检查变量是否属于该NoneType类型。对于其他类型，我们可以执行以下操作：
type([])==list
But for NoneTypethis simple way is not possible. That is, we cannot say type(None)==NoneType. Is there an alternative way? And why is this possible for some types and not for others? Thank you.
但是对于NoneType这种简单的方法是不可能的。也就是说，我们不能说type(None)==NoneType。有没有替代方法？为什么这适用于某些类型而不适用于其他类型？谢谢你。
回答by Alex Hall
NoneTypejust happens to not automatically be in the global scope. This isn't really a problem.
NoneType只是碰巧不会自动在全局范围内。这真的不是问题。
>>> NoneType = type(None)
>>> x = None
>>> type(x) == NoneType
True
>>> isinstance(x, NoneType)
True
In any case it would be unusual to do a type check. Rather you should test x is None.
在任何情况下，进行类型检查都是不寻常的。相反，您应该测试x is None.
回答by Jean-Fran?ois Fabre
Of course you can do it.
你当然可以做到。
type(None)==None.__class__
True
