What is .pyi file
Kexin Tang
  2023-09-12 23:07:23 2023-09-12 23:07   2023-09-12 23:54:50    

Sometimes in VSCode, we want to “jump to declaration”, then IDE redirect us to a file with suffix .pyi, and all it contains are some strange code like this:

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class Object:
    def __init__(self, name: str, age: _T) -> None:
        ...
    
    def get_name(self) -> str:
        ...
    
    def get_age(self) -> _T:
        ...
    
    def __lt__(self, other: Object) -> bool:
        ...
    
    def __add__(self, v: _T) -> _T:
        ...

It looks like .h file in C++, only declares the function signature, typedef, etc without any implementation.

Actually, a .pyi file is not required but recommended, the only purpose for .pyi file is: IDE can provide auto complete and programmer can read the APIs fast and don’t need to care about the implementation details.