This would allow you to **re-use the model** in **multiple places** and also to declare validations and metadata for all the parameters at once. 😎

/// note

This is supported since FastAPI version `0.115.0`. 🤓

///

## Header Parameters with a Pydantic Model { #header-parameters-with-a-pydantic-model }

{*../../docs_src/python_types/tutorial009.py hl[1,4] *}

Utiliser `Optional[str]` plutôt que `str` permettra à l'éditeur de vous aider à détecter les erreurs où vous supposeriez qu'une valeur est toujours de type `str`, alors qu'elle pourrait aussi être `None`.

#### Types génériques

Ancak bir noktada, geçmişteki diğer araçlardan en iyi fikirleri alarak bütün bu çözümleri kapsayan, ayrıca bütün bunları Python'ın daha önce mevcut olmayan özelliklerini (Python 3.6+ ile gelen <abbr title="Tip belirteçleri: Type Hints">tip belirteçleri</abbr>) kullanarak yapan bir şey üretmekten başka seçenek kalmamıştı.

## Daha Önce Geliştirilen Araçlar

### <a href="https://www.djangoproject.com/" class="external-link" target="_blank">Django</a>

### Отключить автоматическую документацию { #disable-the-automatic-docs }

Первый шаг — отключить автоматическую документацию, так как по умолчанию она использует стандартный CDN.

Чтобы отключить её, установите их URL в значение `None` при создании вашего приложения `FastAPI`:

{* ../../docs_src/custom_docs_ui/tutorial001_py39.py hl[8] *}

### Подключить пользовательскую документацию { #include-the-custom-docs }

*Yol operasyonları* sıralı bir şekilde gözden geçirildiğinden dolayı `/users/me` yolunun `/users/{user_id}` yolundan önce tanımlanmış olmasından emin olmanız gerekmektedir:

{* ../../docs_src/path_params/tutorial003.py hl[6,11] *}

     */
    Map<String, String> getUserProperties();

    /**
     * Gets the base directory of the current project (if any).
     *
     * @return The base directory of the current project or {@code null} if none.
     */
    File getProjectDirectory();

    /**
     * Gets current calculated project properties
     *
     * @return The project properties, never {@code null}.
     */

def test_get(client: TestClient):
    response = client.get("/items/baz")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "name": "Baz",
        "description": None,
        "price": 50.2,
        "tax": 10.5,
        "tags": [],
    }


def test_patch_all(client: TestClient):
    response = client.patch(
        "/items/foo",
        json={

    title: `Issue created for Rollback of PR #${pr_number}: ${pr_title}`,
    body: `Merged PR #${pr_number} is rolled back in ${rollback_commit}.
    Please follow up with the reviewer and close this issue once its resolved.`
  });
  return `Issue created: ${resp.data.number} with Title: ${resp.data.title}`;

クエリパラメータの宣言と同様に、モデル属性がデフォルト値をもつとき、必須な属性ではなくなります。それ以外は必須になります。オプショナルな属性にしたい場合は `None` を使用してください。

例えば、上記のモデルは以下の様なJSON「`オブジェクト`」(もしくはPythonの `dict` ) を宣言しています:

```JSON
{
    "name": "Foo",
    "description": "An optional description",
    "price": 45.2,
    "tax": 3.5
}
```

...`description` と `tax` はオプショナル (デフォルト値は `None`) なので、以下のJSON「`オブジェクト`」も有効です:

```JSON
{
    "name": "Foo",
    "price": 45.2

You can define logic (code) that should be executed before the application **starts up**. This means that this code will be executed **once**, **before** the application **starts receiving requests**.

The same way, you can define logic (code) that should be executed when the application is **shutting down**. In this case, this code will be executed **once**, **after** having handled possibly **many requests**.