更多細節請參閱 [Starlette 官方的 Background Tasks 文件](https://www.starlette.dev/background/)。

## 注意事項 { #caveat }

如果你需要執行繁重的背景計算，且不一定要由同一個行程執行（例如不需要共用記憶體、變數等），可以考慮使用更大型的工具，例如 [Celery](https://docs.celeryq.dev)。

這類工具通常需要較複雜的設定，以及訊息/工作佇列管理器（如 RabbitMQ 或 Redis），但它們允許你在多個行程，甚至多台伺服器上執行背景任務。

但如果你需要存取同一個 **FastAPI** 應用中的變數與物件，或只需執行小型的背景任務（例如寄送郵件通知），僅使用 `BackgroundTasks` 即可。

## 重點回顧 { #recap }

 * href="https://www.javadoc.io/doc/com.github.ben-manes.caffeine/caffeine/latest/com.github.benmanes.caffeine/com/github/benmanes/caffeine/cache/Cache.html">{@code
 * Cache}</a>, <a
 * href="https://www.javadoc.io/doc/com.github.ben-manes.caffeine/caffeine/latest/com.github.benmanes.caffeine/com/github/benmanes/caffeine/cache/LoadingCache.html">{@code
 * LoadingCache}</a>, <a

   * preferred assignment.)
   *
   * @since 8.0
   */
  public static final byte DC1 = 17; // aka XON

  /**
   * Transmission On: Although originally defined as DC1, this ASCII control character is now better
   * known as the XON code used for software flow control in serial communications. The main use is

application/lotus-123          wks              # Lotus 123
application/mac-binhex40       hqx              # Macintosh binhexed archives
application/mspowerpoint       ppt              # Microsoft Powerpoint
application/msword             doc              # Microsoft Word
application/octet-stream       bin exe ani      # Binary File
application/oda                oda
application/pagemaker          pm5 pt5 pm       # PageMaker

   <span style="background-color:#007166"><font color="#D3D7CF"> server </font></span>  Documentation at <font color="#729FCF"><u style="text-decoration-style:solid">http://127.0.0.1:8000/docs</u></font>

      <span style="background-color:#007166"><font color="#D3D7CF"> tip </font></span>  Running in development mode, for production use:
             <b>fastapi run</b>

             Logs:

# WebSockets { #websockets }

You can use [WebSockets](https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API) with **FastAPI**.

## Install `websockets` { #install-websockets }

Make sure you create a [virtual environment](../virtual-environments.md), activate it, and install `websockets` (a Python library that makes it easy to use the "WebSocket" protocol):

<div class="termy">

```console
$ pip install websockets

---> 100%
```

Aqui está um exemplo mais completo.

Utilize uma dependência para verificar se o usuário e a senha estão corretos.

Para isso, utilize o módulo padrão do Python [`secrets`](https://docs.python.org/3/library/secrets.html) para verificar o usuário e senha.

# Веб-сокеты { #websockets }

Вы можете использовать [веб-сокеты](https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API) в **FastAPI**.

## Установка `websockets` { #install-websockets }

Убедитесь, что вы создали [виртуальное окружение](../virtual-environments.md), активировали его и установили `websockets` (библиотека Python, упрощающая работу с протоколом "WebSocket"):

<div class="termy">

```console
$ pip install websockets

computação pesada em segundo plano e não necessariamente precisar que seja executada pelo mesmo processo (por exemplo, você não precisa compartilhar memória, variáveis, etc.), pode se beneficiar do uso de outras ferramentas maiores, como o [Celery](https://docs.celeryq.dev).

Elas tendem a exigir configurações mais complexas, um gerenciador de fila de mensagens/tarefas, como RabbitMQ ou Redis, mas permitem executar tarefas em segundo plano em vários processos e, especialmente, em vários servidores....

## Resmi Kılavuz { #official-guide }

Pydantic'in v1'den v2'ye resmi bir [Migration Guide](https://docs.pydantic.dev/latest/migration/)'ı vardır.

Ayrıca nelerin değiştiğini, validasyonların artık nasıl daha doğru ve katı olduğunu, olası dikkat edilmesi gereken noktaları (caveat) vb. de içerir.