* Sie nimmt jeden **Request** entgegen, der an Ihre Anwendung gesendet wird.
* Sie kann dann etwas mit diesem **Request** tun oder beliebigen Code ausführen.
* Dann gibt sie den **Request** zur Verarbeitung durch den Rest der Anwendung weiter (durch eine bestimmte *Pfadoperation*).

```Python hl_lines="2  6"
{!../../../docs_src/advanced_middleware/tutorial001.py!}
```

## `TrustedHostMiddleware`

Enforces that all incoming requests have a correctly set `Host` header, in order to guard against HTTP Host Header attacks.

```Python hl_lines="2  6-8"
{!../../../docs_src/advanced_middleware/tutorial002.py!}
```

The following arguments are supported:

You can add code to be run with the `request`,  before any *path operation* receives it.

And also after the `response` is generated, before returning it.

For example, you could add a custom header `X-Process-Time` containing the time in seconds that it took to process the request and generate a response:

```Python hl_lines="10  12-13"
{!../../../docs_src/middleware/tutorial001.py!}
```

## Other middlewares

Weitere Informationen hierzu finden Sie in der Dokumentation des Repos.

## Full Stack FastAPI MongoDB

... könnte später kommen, abhängig von meiner verfügbaren Zeit und anderen Faktoren. 😅 🎉

## Modelle für maschinelles Lernen mit spaCy und FastAPI

이 경우, 프론트엔드가 제대로 동작하기 위해 `http://localhost:8080`을 목록에 포함해야 합니다.

## 와일드카드

모든 출처를 허용하기 위해 목록을 `"*"` ("와일드카드")로 선언하는 것도 가능합니다.

하지만 이것은 특정한 유형의 통신만을 허용하며, 쿠키 및 액세스 토큰과 사용되는 인증 헤더(Authoriztion header) 등이 포함된 경우와 같이 자격 증명(credentials)이 포함된 통신은 허용되지 않습니다.

따라서 모든 작업을 의도한대로 실행하기 위해, 허용되는 출처를 명시적으로 지정하는 것이 좋습니다.

## `CORSMiddleware` 사용

`CORSMiddleware` 을 사용하여 **FastAPI** 응용 프로그램의 교차 출처 리소스 공유 환경을 설정할 수 있습니다.

It has a `GET` operation that could return an error.

It has a `POST` operation that could return several errors.

Both *path operations* require an `X-Token` header.

=== "Python 3.10+"

    ```Python
    {!> ../../../docs_src/app_testing/app_b_an_py310/main.py!}
    ```

=== "Python 3.9+"

    ```Python

```

👉 🖼, 👥 🚫 📣 🙆 Pydantic 🏷. 👐, 📨 💪 🚫 <abbr title="converted from some plain format, like bytes, into Python objects">🎻</abbr> 🎻, ⚫️ ✍ 🔗 `bytes`, &amp; 🔢 `magic_data_reader()` 🔜 🈚 🎻 ⚫️ 🌌.

👐, 👥 💪 📣 📈 🔗 📨 💪.

### 🛃 🗄 🎚 🆎

⚙️ 👉 🎏 🎱, 👆 💪 ⚙️ Pydantic 🏷 🔬 🎻 🔗 👈 ⤴️ 🔌 🛃 🗄 🔗 📄 *➡ 🛠️*.

&amp; 👆 💪 👉 🚥 💽 🆎 📨 🚫 🎻.

### Create an `Enum` class

Import `Enum` and create a sub-class that inherits from `str` and from `Enum`.

By inheriting from `str` the API docs will be able to know that the values must be of type `string` and will be able to render correctly.

Then create class attributes with fixed values, which will be the available valid values:

```Python hl_lines="1  6-9"
{!../../../docs_src/path_params/tutorial005.py!}
```

!!! info

# Header 参数

定义 `Header` 参数的方式与定义 `Query`、`Path`、`Cookie` 参数相同。

## 导入 `Header`

首先，导入 `Header`：

=== "Python 3.10+"

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

=== "Python 3.9+"

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

=== "Python 3.8+"

    ```Python hl_lines="3"

# Header-параметры

Вы можете определить параметры заголовка таким же образом, как вы определяете параметры `Query`, `Path` и `Cookie`.

## Импорт `Header`

Сперва импортируйте `Header`:

=== "Python 3.10+"

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

=== "Python 3.9+"

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