### The main app file

Now we create a dependency that returns a new `config.Settings()`.

=== "Python 3.9+"

    ```Python hl_lines="6  12-13"
    {!> ../../../docs_src/settings/app02_an_py39/main.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="6  12-13"
    {!> ../../../docs_src/settings/app02_an/main.py!}
    ```

=== "Python 3.8+ non-Annotated"

    !!! tip

Es wird nur einmal generiert und dann wird dasselbe zwischengespeicherte Schema für die nächsten Requests verwendet.

```Python hl_lines="13-14  25-26"
{!../../../docs_src/extending_openapi/tutorial001.py!}
```

### Die Methode überschreiben

Jetzt können Sie die Methode `.openapi()` durch Ihre neue Funktion ersetzen.

```Python hl_lines="29"

## 检查用户名

以下是更完整的示例。

使用依赖项检查用户名与密码是否正确。

为此要使用 Python 标准模块 <a href="https://docs.python.org/3/library/secrets.html" class="external-link" target="_blank">`secrets`</a> 检查用户名与密码：

```Python hl_lines="1  11-13"
{!../../../docs_src/security/tutorial007.py!}
```

这段代码确保 `credentials.username` 是 `"stanleyjobson"`，且 `credentials.password` 是`"swordfish"`。与以下代码类似：

```Python

请注意，现在我们不创建默认实例 `settings = Settings()`。

### 主应用程序文件

现在我们创建一个依赖项，返回一个新的 `config.Settings()`。

=== "Python 3.9+"

    ```Python hl_lines="6  12-13"
    {!> ../../../docs_src/settings/app02_an_py39/main.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="6  12-13"
    {!> ../../../docs_src/settings/app02_an/main.py!}
    ```

=== "Python 3.8+ 非注解版本"

    !!! tip
        如果可能，请尽量使用 `Annotated` 版本。

    {!> ../../../docs_src/dependencies/tutorial002_an.py!}
    ```

=== "Python 3.10+ non-Annotated"

    !!! tip
        Prefer to use the `Annotated` version if possible.

    ```Python hl_lines="9-13"
    {!> ../../../docs_src/dependencies/tutorial002_py310.py!}
    ```

=== "Python 3.8+ non-Annotated"

    !!! tip
        Prefer to use the `Annotated` version if possible.

Jetzt erstellen wir eine Abhängigkeit, die ein neues `config.Settings()` zurückgibt.

=== "Python 3.9+"

    ```Python hl_lines="6  12-13"
    {!> ../../../docs_src/settings/app02_an_py39/main.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="6  12-13"
    {!> ../../../docs_src/settings/app02_an/main.py!}
    ```

=== "Python 3.8+ nicht annotiert"

    !!! tip "Tipp"

  // deprecatedFirstTimestamp is the deprecated field assuring backward compatibility with core.v1 Event type.
  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.Time deprecatedFirstTimestamp = 13;

  // deprecatedLastTimestamp is the deprecated field assuring backward compatibility with core.v1 Event type.
  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.Time deprecatedLastTimestamp = 14;

In this example, the *path operations* under the `router` will use the custom `TimedRoute` class, and will have an extra `X-Response-Time` header in the response with the time it took to generate the response:

```Python hl_lines="13-20"
{!../../../docs_src/custom_request_and_route/tutorial003.py!}

```Python hl_lines="26"
{!../../../docs_src/custom_request_and_route/tutorial003.py!}
```

本例中，*路径操作*下的 `router` 使用自定义的 `TimedRoute` 类，并在响应中包含输出生成响应时间的 `X-Response-Time` 响应头：

```Python hl_lines="13-20"
{!../../../docs_src/custom_request_and_route/tutorial003.py!}

```Python hl_lines="13-20"
{!../../../docs_src/custom_request_and_route/tutorial003.py!}