from typing import Union from pydantic import BaseModel class ItemBase(BaseModel): title: str description: Union[str, None] = None class ItemCreate(ItemBase): pass class Item(ItemBase): id: int owner_id: int class Config: from_attributes = True class UserBase(BaseModel): email: str class UserCreate(UserBase): password: str class User(UserBase): id: int is_active: bool items: list[Item] = [] class Config: from_attributes = True