from typing import Union from fastapi import FastAPI app = FastAPI() @app.get("/items/{item_id}") async def read_item(item_id: str, q: Union[str, None] = None, short: bool = False): item = {"item_id": item_id} if q: item.update({"q": q}) if not short: item.update( {"description": "This is an amazing item that has a long description"} ) return item