import dataclasses from pydantic import ValidationError from pydantic.dataclasses import dataclass as pydantic_dataclass, set_validation @dataclasses.dataclass class User: id: int name: str # Enhance stdlib dataclass pydantic_dataclass(User) user1 = User(id='whatever', name='I want') # validate data of `user1` try: user1.__pydantic_validate_values__() except ValidationError as e: print(e) # Enforce validation try: with set_validation(User, True): User(id='whatever', name='I want') except ValidationError as e: print(e)