from typing import Annotated, Union from fastapi import Body, FastAPI from pydantic import BaseModel app = FastAPI() class Item(BaseModel): name: str description: Union[str, None] = None price: float tax: Union[float, None] = None @app.put("/items/{item_id}") async def update_item(item_id: int, item: Annotated[Item, Body(embed=True)]): results = {"item_id": item_id, "item": item} return results