[ Python 常見問題 ] Type hints with user defined classes

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Question
Couldn't seem to find a definitive answer. I want to do a type hint for a function and the type being some custom class that I have defined, called it CustomClass. And then let's say in some function, call it FuncA(arg), I have one argument named arg. Would the correct way to type hint FuncA be:

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1. def FuncA(arg: CustomClass):  

Or would it be:

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1. def FuncA(Arg:Type[CustomClass]):  

HowTo
The former is correct, if arg accepts an instance of CustomClass:

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1. def FuncA(arg: CustomClass):  
2.     #     ^ instance of CustomClass  

In case you want the class CustomClass itself (or a subtype), then you should write:

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1. from typing import Type  # you have to import Type  
2.   
3. def FuncA(arg: Type[CustomClass]):  
4.     #     ^ CustomClass (class object) itself  

Like it is written in the documentation about Typing:

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1. class typing.Type(Generic[CT_co])  

A variable annotated with C may accept a value of type C. In contrast, a variable annotated with Type[C] may accept values that are classes themselves - specifically, it will accept the class object of C.

The documentation includes an example with the int class:

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1. a = 3         # Has type 'int'  
2. b = int       # Has type 'Type[int]'  
3. c = type(a)   # Also has type 'Type[int]'