你还可以通过将默认值设置为 `None` 来将请求体参数声明为可选参数：

//// tab | Python 3.10+

```Python hl_lines="18-20"
{!> ../../docs_src/body_multiple_params/tutorial001_an_py310.py!}
```

////

//// tab | Python 3.9+

```Python hl_lines="18-20"
{!> ../../docs_src/body_multiple_params/tutorial001_an_py39.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="19-21"

Dazu deklarieren wir eine Methode `__call__`:

//// tab | Python 3.9+

```Python hl_lines="12"
{!> ../../docs_src/dependencies/tutorial011_an_py39.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="11"
{!> ../../docs_src/dependencies/tutorial011_an.py!}
```

////

//// tab | Python 3.8+ nicht annotiert

/// tip | "Tipp"

And another one to authenticate and return a user.

//// tab | Python 3.10+

```Python hl_lines="8  49  56-57  60-61  70-76"
{!> ../../docs_src/security/tutorial004_an_py310.py!}
```

////

//// tab | Python 3.9+

```Python hl_lines="8  49  56-57  60-61  70-76"
{!> ../../docs_src/security/tutorial004_an_py39.py!}
```

////

//// tab | Python 3.8+

        builder.addSort("_score", SortOrder.DESC);

        // set filter query.
        final List<QueryBuilder> filterList = new ArrayList<>(10);
        if (!tags.isEmpty()) {
            filterList.add(buildFilterQuery(FieldNames.TAGS, tags));
        }

        roles.add(SuggestConstants.DEFAULT_ROLE);
        if (!roles.isEmpty()) {
            filterList.add(buildFilterQuery(FieldNames.ROLES, roles));

from fastapi import APIRouter, Depends, HTTPException

from ..dependencies import get_token_header

router = APIRouter(
    prefix="/items",
    tags=["items"],
    dependencies=[Depends(get_token_header)],
    responses={404: {"description": "Not found"}},
)


fake_items_db = {"plumbus": {"name": "Plumbus"}, "gun": {"name": "Portal Gun"}}


@router.get("/")
async def read_items():
    return fake_items_db

## `Cookie` 임포트

먼저 `Cookie`를 임포트합니다:

//// tab | Python 3.10+

```Python hl_lines="3"
{!> ../../docs_src/cookie_params/tutorial001_an_py310.py!}
```

////

//// tab | Python 3.9+

```Python hl_lines="3"
{!> ../../docs_src/cookie_params/tutorial001_an_py39.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="3"

reen"]',he=".content-wrapper",ge=".content-wrapper iframe",pe=".content-wrapper.iframe-mode .nav",me=".content-wrapper.iframe-mode .navbar-nav",ve=me+" .nav-item",_e=me+" .nav-link",be=".content-wrapper.iframe-mode .tab-content",ye=be+" .tab-empty",Ce=be+" .tab-loading",we=be+" .tab-pane",xe=".main-sidebar .nav-item > a.nav-link",Ie=".main-header .nav-item a.nav-link",Te=".main-header a.dropdown-item",Se="iframe-mode",je="iframe-mode-fullscreen",ke={onTabClick:function(e){return e},onTabChanged:function(e){return...

    description: Union[str, None] = None
    price: Union[float, None] = None
    tax: float = 10.5
    tags: List[str] = []


items = {
    "foo": {"name": "Foo", "price": 50.2},
    "bar": {"name": "Bar", "description": "The bartenders", "price": 62, "tax": 20.2},
    "baz": {"name": "Baz", "description": None, "price": 50.2, "tax": 10.5, "tags": []},
}


@app.get("/items/{item_id}", response_model=Item)

## Імпорт `Field`

Спочатку вам потрібно імпортувати це:

//// tab | Python 3.10+

```Python hl_lines="4"
{!> ../../docs_src/body_fields/tutorial001_an_py310.py!}
```

////

//// tab | Python 3.9+

```Python hl_lines="4"
{!> ../../docs_src/body_fields/tutorial001_an_py39.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="4"
{!> ../../docs_src/body_fields/tutorial001_an.py!}

                            {"title": "Description", "type": "string"}
                        ),
                        "tax": {"title": "Tax", "type": "number", "default": 10.5},
                        "tags": {
                            "title": "Tags",
                            "type": "array",
                            "items": {"type": "string"},
                            "default": [],
                        },