Metaclass

class RegistryMeta(type):
    registry: dict[str, type] = {}

    def __new__(mcls, name, bases, ns):
        cls = super().__new__(mcls, name, bases, ns)
        if name != 'Plugin':
            mcls.registry[name.lower()] = cls
        return cls

class Plugin(metaclass=RegistryMeta):
    pass

class CsvPlugin(Plugin):
    pass

print(RegistryMeta.registry)