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