Wir hatten diese Typannotation:

//// tab | Python 3.10+

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

////

//// tab | Python 3.9+

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

////

Was wir tun werden, ist, dies mit `Annotated` zu wrappen, sodass es zu:

//// tab | Python 3.10+

```Python
q: Annotated[str | None] = None
```

////

//// tab | Python 3.9+

```Python

items = {"foo": {"name": "Fighters", "size": 6}, "bar": {"name": "Tenders", "size": 3}}


@app.put("/items/{item_id}")
async def upsert_item(
    item_id: str,
    name: Union[str, None] = Body(default=None),
    size: Union[int, None] = Body(default=None),
):
    if item_id in items:
        item = items[item_id]
        item["name"] = name
        item["size"] = size
        return item
    else:

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None
    tags: set[str] = set()


@app.post(
    "/items/",
    response_model=Item,
    summary="Create an item",
    response_description="The created item",
)
async def create_item(item: Item):
    """

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
    tags: set[str] = set()


@app.post(
    "/items/",
    response_model=Item,
    summary="Create an item",
    response_description="The created item",
)

Поскольку по умолчанию, отдельные значения интерпретируются как query-параметры, вам не нужно явно добавлять `Query`, вы можете просто сделать так:

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

Или в Python 3.10 и выше:

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

Например:

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

/// info | Информация

    [
        ("/items", None, 200, {"ads_id": None}),
        ("/items", {"ads_id": "ads_track"}, 200, {"ads_id": "ads_track"}),
        (
            "/items",
            {"ads_id": "ads_track", "session": "cookiesession"},
            200,
            {"ads_id": "ads_track"},
        ),
        ("/items", {"session": "cookiesession"}, 200, {"ads_id": None}),
    ],
)

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(
            openapi_examples={

                "loc": ["header", "x-token"],
                "msg": "Field required",
                "input": None,
            },
            {
                "type": "missing",
                "loc": ["header", "x-key"],
                "msg": "Field required",
                "input": None,
            },
        ]
    }


def test_get_no_headers_users(client: TestClient):

class CallableGenDependency:
    def __call__(self, value: str) -> Generator[str, None, None]:
        yield value


class AsyncCallableDependency:
    async def __call__(self, value: str) -> str:
        return value


class AsyncCallableGenDependency:
    async def __call__(self, value: str) -> AsyncGenerator[str, None]:
        yield value


class MethodsDependency:

@SuppressWarnings("checkstyle:InterfaceIsType")
public interface Language extends ExtensibleEnum {

    /**
     * The "none" language. It is not versioned, family is same to itself, and compatible with itself only.
     * In turn, every {@link Language} implementation must be compatible with {@code NONE} language.
     */
    Language NONE = language("none");

    /**
     * The "resources" language. This is used for files such as images to provide in the output.