Final methods

Like with attributes, sometimes it is useful to protect a method fromoverriding. You can use the typing_extensions.finaldecorator for this purpose:

from typing_extensions import final
 
class Base:
    @final
    def common_name(self) -> None:
        ...
 
class Derived(Base):
    def common_name(self) -> None:  # Error: cannot override a final method
        ...

This @final decorator can be used with instance methods, class methods,static methods, and properties.

For overloaded methods you should add @final on the implementationto make it final (or on the first overload in stubs):

from typing import Any, overload
 
class Base:
    @overload
    def method(self) -> None: ...
    @overload
    def method(self, arg: int) -> int: ...
    @final
    def method(self, x=None):
        ...