Alternative to namedtuple and dataclass in Python

metaclass.py

class Metaclass:
    def asdict(self):
        return self.__dict__

    def astuple(self):
        return tuple(self.__dict__.values())

    def fields(self):
        return list(self.__dict__.keys())


class User(Metaclass):
    def __init__(self, name="", password="secret", related=None):
        self.name = name
        self.password = password
        self.related = related