Da einfache Werte standardmäßig als Query-Parameter interpretiert werden, müssen Sie `Query` nicht explizit hinzufügen, Sie können einfach schreiben:

```Python
q: Union[str, None] = None
```

Oder in Python 3.10 und darüber:

```Python
q: str | None = None
```

Zum Beispiel:

{* ../../docs_src/body_multiple_params/tutorial004_an_py310.py hl[28] *}

/// info | Info

    assert response.json() == {
        "detail": [
            {
                "type": "missing",
                "loc": ["query", "query"],
                "msg": "Field required",
                "input": None,
            }
        ]
    }


def test_query_query_baz():
    response = client.get("/query?query=baz")
    assert response.status_code == 200
    assert response.json() == "foo bar baz"

        raise ValueError('Invalid ID format, it must start with "isbn-" or "imdb-"')
    return id


@app.get("/items/")
async def read_items(
    id: Annotated[Union[str, None], AfterValidator(check_valid_id)] = None,
):
    if id:
        item = data.get(id)
    else:
        id, item = random.choice(list(data.items()))

    if oauth_header is None:
        return None
    user = User(username=oauth_header)
    return user


@app.post("/login")
def login(form_data: OAuth2PasswordRequestFormStrict = Depends()):
    return form_data


@app.get("/users/me")
def read_users_me(current_user: Optional[User] = Depends(get_current_user)):
    if current_user is None:
        return {"msg": "Create an account first"}

    assert response.status_code == 200
    assert response.json() == {
        "host": "testserver",
        "save_data": True,
        "if_modified_since": None,
        "traceparent": None,
        "x_tag": [],
    }


def test_header_param_model_invalid(client: TestClient):
    response = client.get("/items/")
    assert response.status_code == 422

					done = true
				}
			}
		case <-ctx.Done():
			// Capture timedout locks as failed or took too long
			locksFailed++
			if locksFailed > tolerance {
				// We know that we are not going to get the lock anymore,
				// so exit out and release any locks that did get acquired
				done = true
			}
		}

		if done {
			break
		}
	}

        "title": body_model_name,
        "type": "object",
    }


@pytest.mark.parametrize("json", [None, {}])
@pytest.mark.parametrize(
    "path",
    ["/required-list-str", "/model-required-list-str"],
)
def test_required_list_str_missing(path: str, json: Union[dict, None]):
    client = TestClient(app)
    response = client.post(path, json=json)
    assert response.status_code == 422

from typing import Optional


def say_hi(name: Optional[str] = None):
    if name is not None:
        print(f"Hey {name}!")
    else:

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(
    strange_header: str | None = Header(default=None, convert_underscores=False),
):

from typing import Annotated

from fastapi import Cookie, FastAPI

app = FastAPI()


@app.get("/items/")
async def read_items(ads_id: Annotated[str | None, Cookie()] = None):