Und wenn Sie ein `response_model` deklariert haben, wird es weiterhin zum Filtern und Konvertieren des von Ihnen zurückgegebenen Objekts verwendet.

////

//// tab | 🐍 3️⃣.1️⃣0️⃣ & 🔛

```Python hl_lines="7"
{!> ../../docs_src/query_params/tutorial002_py310.py!}
```

////

👉 💼, 🔢 🔢 `q` 🔜 📦, & 🔜 `None` 🔢.

/// check

👀 👈 **FastAPI** 🙃 🥃 👀 👈 ➡ 🔢 `item_id` ➡ 🔢 & `q` 🚫,, ⚫️ 🔢 🔢.

///

## 🔢 🔢 🆎 🛠️

👆 💪 📣 `bool` 🆎, & 👫 🔜 🗜:

//// tab | 🐍 3️⃣.6️⃣ & 🔛

```Python hl_lines="9"

```

////

Bu durumda, `q` fonksiyon parametresi isteğe bağlı olacak ve varsayılan değer olarak `None` alacaktır.

/// check | "Ek bilgi"

Ayrıca, dikkatinizi çekerim ki; **FastAPI**, `item_id` parametresinin bir yol parametresi olduğunu ve `q` parametresinin yol değil bir sorgu parametresi olduğunu fark edecek kadar beceriklidir.

///

## Sorgu Parametresi Tip Dönüşümü

`Cookie` ist eine Schwesterklasse von `Path` und `Query`. Sie erbt von derselben gemeinsamen `Param`-Elternklasse.

Aber erinnern Sie sich, dass, wenn Sie `Query`, `Path`, `Cookie` und andere von `fastapi` importieren, diese tatsächlich Funktionen sind, welche spezielle Klassen zurückgeben.

///

/// info

///

```Python hl_lines="9"
{!> ../../docs_src/cookie_params/tutorial001.py!}
```

////

/// note | "技术细节"

`Cookie` 、`Path` 、`Query` 是**兄弟类**，都继承自共用的 `Param` 类。

注意，从 `fastapi` 导入的 `Query`、`Path`、`Cookie` 等对象，实际上是返回特殊类的函数。

///

/// info | "说明"

必须使用 `Cookie` 声明 cookie 参数，否则该参数会被解释为查询参数。

///

## 小结

from typing import Any, List

from dirty_equals import IsOneOf
from fastapi.params import Body, Cookie, Depends, Header, Param, Path, Query

test_data: List[Any] = ["teststr", None, ..., 1, []]


def get_user():
    return {}  # pragma: no cover


def test_param_repr_str():
    assert repr(Param("teststr")) == "Param(teststr)"


def test_param_repr_none():
    assert repr(Param(None)) == "Param(None)"

{!../../docs_src/path_operation_advanced_configuration/tutorial003.py!}
```

## docstringによる説明の高度な設定

*path operation関数* のdocstringからOpenAPIに使用する行を制限することができます。

`\f` (「書式送り (Form Feed)」のエスケープ文字) を付与することで、**FastAPI** はOpenAPIに使用される出力をその箇所までに制限します。

ドキュメントには表示されませんが、他のツール (例えばSphinx) では残りの部分を利用できるでしょう。

```Python hl_lines="19-29"
{!../../docs_src/path_operation_advanced_configuration/tutorial004.py!}

    page.screenshot(path="docs/en/docs/img/tutorial/header-param-models/image01.png")

    # ---------------------
    context.close()
    browser.close()


process = subprocess.Popen(
    ["fastapi", "run", "docs_src/header_param_models/tutorial001.py"]
)
try:
    for _ in range(3):
        try:
            response = httpx.get("http://localhost:8000/docs")
        except httpx.ConnectError:

    page.screenshot(path="docs/en/docs/img/tutorial/request-form-models/image01.png")

    # ---------------------
    context.close()
    browser.close()


process = subprocess.Popen(
    ["fastapi", "run", "docs_src/request_form_models/tutorial001.py"]
)
try:
    for _ in range(3):
        try:
            response = httpx.get("http://localhost:8000/docs")
        except httpx.ConnectError:

import pytest
from fastapi.testclient import TestClient


@pytest.fixture(name="client")
def get_client():
    from docs_src.dependencies.tutorial008d import app

    client = TestClient(app)
    return client


def test_get_no_item(client: TestClient):
    response = client.get("/items/foo")
    assert response.status_code == 404, response.text
    assert response.json() == {"detail": "Item not found, there's only a plumbus here"}