hook_classmethod

FunctionPrivateSource

hooked_method: Callable[P, T] = hook_classmethod[**P, _Type, T](
    cls_method: Callable[P, T],
    hook_before: Callable[Concatenate[_Type, P], None] | None = None,
    hook_after: Callable[Concatenate[_Type, P], None] | None = None,
)

Hook a class method.

Arguments

Requires

Argument	Type	Required	Description
cls_method	(**P) -> T		A class method that is hooked. This is the bounded version of the class method, where the first argument cls has been implied and not included in the spec P.
hook_before	None | ((_Type, **P) -> None)		The hook that will be run before this class method.
hook_after	None | ((_Type, **P) -> None)		The hook that will be run after this class method.

Returns

Argument	Type	Description
hooked_method	(**P) -> T	The hooked class method, where the first argument (class) is hidden.

Examples

Hook a class with __init_subclass__ defined

Codes

hook_init_subclass.py

import flask_sqlalchemy_compat as fsc


class ExampleBase:
    test_val = 0

    def __init_subclass__(cls) -> None:
        cls.test_val = 1


class ExampleA(ExampleBase):
    pass


def hook(cls: ExampleBase) -> None:
    cls.test_val = 10


ExampleBase.__init_subclass__ = fsc.utilities.hook_classmethod(
    ExampleBase.__init_subclass__, hook_after=hook
)


class ExampleB(ExampleBase):
    pass


if __name__ == "__main__":
    print("ExampleBase.test_val:", ExampleBase.test_val)
    print("ExampleA.test_val:", ExampleA.test_val)
    print("ExampleB.test_val:", ExampleB.test_val)

Results

ExampleBase.test_val: 0
ExampleA.test_val: 1
ExampleB.test_val: 10