import dataclasses import pydantic @dataclasses.dataclass class Z: z: int @dataclasses.dataclass class Y(Z): y: int = 0 @pydantic.dataclasses.dataclass class X(Y): x: int = 0 foo = X(x=b'1', y='2', z='3') print(foo) try: X(z='pika') except pydantic.ValidationError as e: print(e)