* <a href="https://pythonhosted.org/itsdangerous/" target="_blank"><code>itsdangerous</code></a> - Requerido para dar soporte a `SessionMiddleware`.
* <a href="https://pyyaml.org/wiki/PyYAMLDocumentation" target="_blank"><code>pyyaml</code></a> - Requerido para dar soporte al `SchemaGenerator` de Starlette (probablemente no lo necesites con FastAPI).

- <a href="https://pythonhosted.org/itsdangerous/" target="_blank"><code>itsdangerous</code></a> - `SessionMiddleware` সহায়তার জন্য প্রয়োজন।
- <a href="https://pyyaml.org/wiki/PyYAMLDocumentation" target="_blank"><code>pyyaml</code></a> - স্টারলেটের SchemaGenerator সাপোর্ট এর জন্য প্রয়োজন (আপনার সম্ভাবত FastAPI প্রয়োজন নেই)।

    * There is a **solution** to this, however.
* There's an **extension** to the **TLS** protocol (the one handling the encryption at the TCP level, before HTTP) called **<a href="https://en.wikipedia.org/wiki/Server_Name_Indication" class="external-link" target="_blank"><abbr title="Server Name Indication">SNI</abbr></a>**.

Any variable that is put inside of `{}` in an f-string will be expanded / injected in the string.

### `dict` unpacking

# WebSockets

Sie können <a href="https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API" class="external-link" target="_blank">WebSockets</a> mit **FastAPI** verwenden.

## `WebSockets` installieren

Zuerst müssen Sie `WebSockets` installieren:

<div class="termy">

```console
$ pip install websockets

---> 100%
```

</div>

## WebSockets-Client

### In Produktion

你可以用作 TLS 终止代理的一些选项包括：

* Traefik（也可以处理证书更新）
* Caddy（也可以处理证书更新）
* Nginx
* HAProxy

## Let's Encrypt

在 Let's Encrypt 之前，这些 **HTTPS 证书** 由受信任的第三方出售。

过去，获得这些证书的过程非常繁琐，需要大量的文书工作，而且证书非常昂贵。

Следовательно, строка:

```Python
    uvicorn.run(app, host="0.0.0.0", port=8000)
```

не будет выполнена.

!!! info "Информация"
    Для получения дополнительной информации, ознакомьтесь с <a href="https://docs.python.org/3/library/__main__.html" class="external-link" target="_blank">официальной документацией Python</a>.

## Запуск вашего кода с помощью отладчика

**FastAPI** 要确保从正确的位置读取数据，而不是读取 JSON。

!!! note "技术细节"

    表单数据的「媒体类型」编码一般为 `application/x-www-form-urlencoded`。

    但包含文件的表单编码为 `multipart/form-data`。文件处理详见下节。

    编码和表单字段详见 <a href="https://developer.mozilla.org/zh-CN/docs/Web/HTTP/Methods/POST" class="external-link" target="_blank"><abbr title="Mozilla Developer Network">MDN</abbr> Web 文档的 <code>POST</code></a>小节。

!!! warning "警告"

🏆 👫 ⚒ 🔢 (💪 🔀), 💖 💽 📛. & 📚 💪 🚿, 💖 ㊙.

👉 🤔 ⚫️ ⚠ 🚚 👫 🌐 🔢 👈 ✍ 🈸.

## 🌐 🔢

!!! tip
    🚥 👆 ⏪ 💭 ⚫️❔ "🌐 🔢" & ❔ ⚙️ 👫, 💭 🆓 🚶 ⏭ 📄 🔛.

<a href="https://en.wikipedia.org/wiki/Environment_variable" class="external-link" target="_blank">🌐 🔢</a> (💭 "🇨🇻 {") 🔢 👈 🖖 🏞 🐍 📟, 🏃‍♂ ⚙️, &amp; 💪 ✍ 👆 🐍 📟 (⚖️ 🎏 📋 👍).

👆 💪 ✍ &amp; ⚙️ 🌐 🔢 🐚, 🍵 💆‍♂ 🐍:

=== "💾, 🇸🇻, 🚪 🎉"

* `response`를 반환하기 전에 추가로 `response`를 수정할 수 있습니다.

```Python hl_lines="8-9  11  14"
{!../../../docs_src/middleware/tutorial001.py!}
```

!!! tip "팁"
    사용자 정의 헤더는 <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">'X-' 접두사를 사용</a>하여 추가할 수 있습니다.