from pydantic import BaseModel, SecretStr

class MyBaseModel(BaseModel):
    def model_dump(self, **kwargs):
        # use super's model_dump, with serialize_as_any set to True by default
        return super().model_dump(serialize_as_any=True, **kwargs)
    
    def model_dump_json(self, **kwargs):
        # use super's model_dump_json, with serialize_as_any set to True by default
        return super().model_dump_json(serialize_as_any=True, **kwargs)


class User(BaseModel):
    name: str

class UserInfo(User):
    password: SecretStr

class OuterModel(MyBaseModel):
    user: User

u = OuterModel(user=UserInfo(name='John', password='secret_pw'))
print(u.model_dump_json())
#> {"user":{"name":"John","password":"**********"}}