I found some examples on how to use ObjectId within BaseModel classes. Basically, this can be achieved by creating a Pydantic-friendly class as follows: class PyObjectId(ObjectId): @classmethod def __get_validators__(cls): yield cls.validate @classmethod def validate(cls, v): if not ObjectId.is_valid(v): raise ValueError("Invalid objectid") return ObjectId(v) @classmethod def __modify_schema__(cls, field_schema): field_schema.update(type="string") However, this seems to be for Pydantic v1, as this mechanism has been superseeded by the __get_pydantic_core_schema__ classmethod. However, I have been unable to achieve an equivalent solution with Pydantic v2. Is it possible? What validators do I need? I tried to refactor things but was unable to get anything usable. Continue reading...
