{!../../../docs_src/middleware/tutorial001.py!}
```

## 其他中间件

你可以稍后在 [Advanced User Guide: Advanced Middleware](../advanced/middleware.md){.internal-link target=_blank}阅读更多关于中间件的教程.

<img src="/img/tutorial/path-params/image03.png">

### Mit Python-*<abbr title="Enumeration – Aufzählung">Enums</abbr>* arbeiten

Der *Pfad-Parameter* wird ein *<abbr title="Member – Mitglied: Einer der möglichen Werte einer Enumeration">Member</abbr> eines Enums* sein.

#### *Enum-Member* vergleichen

Es wird ein JSON angezeigt, welches ungefähr so aussieht:

```JSON
{
    "openapi": "3.1.0",
    "info": {
        "title": "FastAPI",
        "version": "0.1.0"
    },
    "paths": {
        "/items/": {
            "get": {
                "responses": {
                    "200": {

    In this case, it's a list of `Item` dataclasses.

6. Here we are returning a dictionary that contains `items` which is a list of dataclasses.

    FastAPI is still capable of <abbr title="converting the data to a format that can be transmitted">serializing</abbr> the data to JSON.

7. Here the `response_model` is using a type annotation of a list of `Author` dataclasses.

In this section we'll see how to use other middlewares.

## Adding ASGI middlewares

As **FastAPI** is based on Starlette and implements the <abbr title="Asynchronous Server Gateway Interface">ASGI</abbr> specification, you can use any ASGI middleware.

A middleware doesn't have to be made for FastAPI or Starlette to work, as long as it follows the ASGI spec.

    ```

## Validierung von Zahlen: Floats, größer und kleiner

Zahlenvalidierung funktioniert auch für <abbr title="Kommazahl">`float`</abbr>-Werte.

🔢, ⚫️❔ 👩‍🔬 `.openapi()` 🔨 ✅ 🏠 `.openapi_schema` 👀 🚥 ⚫️ ✔️ 🎚 & 📨 👫.

🚥 ⚫️ 🚫, ⚫️ 🏗 👫 ⚙️ 🚙 🔢 `fastapi.openapi.utils.get_openapi`.

& 👈 🔢 `get_openapi()` 📨 🔢:

* `title`: 🗄 📛, 🎦 🩺.
* `version`: ⏬ 👆 🛠️, ✅ `2.5.0`.
* `openapi_version`: ⏬ 🗄 🔧 ⚙️. 🔢, ⏪: `3.0.2`.
* `description`: 📛 👆 🛠️.
* `routes`: 📇 🛣, 👫 🔠 ® *➡ 🛠️*. 👫 ✊ ⚪️➡️ `app.routes`.

## 🔑 🔢

<!-- sponsors -->

{% if sponsors %}
{% for sponsor in sponsors.gold -%}
<a href="{{ sponsor.url }}" target="_blank" title="{{ sponsor.title }}"><img src="{{ sponsor.img }}" style="border-radius:15px"></a>
{% endfor -%}
{%- for sponsor in sponsors.silver -%}
<a href="{{ sponsor.url }}" target="_blank" title="{{ sponsor.title }}"><img src="{{ sponsor.img }}" style="border-radius:15px"></a>
{% endfor %}
{% endif %}

<!-- /sponsors -->

### 导入 `APIRouter`

你可以导入它并通过与 `FastAPI` 类相同的方式创建一个「实例」：

```Python hl_lines="1  3" title="app/routers/users.py"
{!../../../docs_src/bigger_applications/app/routers/users.py!}
```

### 使用 `APIRouter` 的*路径操作*

然后你可以使用它来声明*路径操作*。

使用方式与 `FastAPI` 类相同：

```Python hl_lines="6  11  16" title="app/routers/users.py"
{!../../../docs_src/bigger_applications/app/routers/users.py!}
```

🔜 🔄 📨 ❌ 🏬 💖:

```JSON
{
  "title": "towel",
  "size": "XL"
}
```

👆 🔜 📨 📨 💬 👆 👈 💽 ❌ ⚗ 📨 💪:

```JSON hl_lines="12-15"
{
  "detail": [
    {
      "loc": [
        "body",
        "size"
      ],
      "msg": "value is not a valid integer",
      "type": "type_error.integer"
    }
  ],
  "body": {
    "title": "towel",
    "size": "XL"
  }
}