from typing import Union from fastapi import FastAPI from pydantic import BaseModel app = FastAPI() class Item(BaseModel): name: str description: Union[str, None] = None price: float tax: Union[float, None] = None class Config: schema_extra = { "examples": [ { "name": "Foo", "description": "A very nice Item", "price": 35.4, "tax": 3.2, } ] } @app.put("/items/{item_id}") async def update_item(item_id: int, item: Item): results = {"item_id": item_id, "item": item} return results