Shared via mypy Playground

main.py

from typing import ClassVar, Final, Self, Any


class Interface:

    # Every subclass has a _name attribute (set by __init_subclass__)
    _name: ClassVar[Final[str]]

    # Registry of subclasses
    _iftypes: ClassVar[Final[dict[str, type[Self]]]] = {}

    def __init_subclass__(cls, **kwargs: Any) -> None:
        super().__init_subclass__(**kwargs)
        name = cls.__name__.lower()
        cls._name = name
        cls._iftypes[name] = cls

    def __init__(self, ifname: str) -> None:
        self._ifname = ifname

    @classmethod
    def from_registry(cls, name: str, kind: str) -> Self:
        #ifcls: type[Self] | None = cls._iftypes.get(kind)
        ifcls = cls._iftypes.get(kind)
        if ifcls is None:
            raise ValueError()
        return ifcls(name)


class Bond(Interface):
    pass


class Bridge(Interface):
    pass


class VLAN(Interface):
    pass


for kind, ifcls in Interface._iftypes.items():
    print(f'{kind}: {ifcls.__name__}')