# WebSockets { #websockets }

Você pode usar [WebSockets](https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API) com **FastAPI**.

## Instale `websockets` { #install-websockets }

Garanta que você criou um [ambiente virtual](../virtual-environments.md), o ativou e instalou o `websockets` (uma biblioteca Python que facilita o uso do protocolo "WebSocket"):

<div class="termy">

```console
$ pip install websockets

---> 100%
```

    - 然後回傳對應*路徑操作*所產生的 `response`。
- 然後你可以在回傳之前進一步修改 `response`。

{* ../../docs_src/middleware/tutorial001_py310.py hl[8:9,11,14] *}

/// tip

請記得，自訂的非標準標頭可以[使用 `X-` 前綴](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers)。

但如果你有自訂標頭並希望瀏覽器端的用戶端能看到它們，你需要在 CORS 設定（[CORS（跨來源資源共用）](cors.md)）中使用 [Starlette 的 CORS 文件](https://www.starlette.dev/middleware/#corsmiddleware)所記載的參數 `expose_headers` 將它們加入。

///

注意，`status_code` 是（`get`、`post` 等）**装饰器**方法中的参数。与之前的参数和请求体不同，不是*路径操作函数*的参数。

///

`status_code` 参数接收表示 HTTP 状态码的数字。

/// info | 信息

`status_code` 还能接收 `IntEnum` 类型，比如 Python 的 [`http.HTTPStatus`](https://docs.python.org/3/library/http.html#http.HTTPStatus)。

///

它可以：

* 在响应中返回状态码
* 在 OpenAPI 概图（及用户界面）中存档：

<img src="/img/tutorial/response-status-code/image01.png">

/// note | 注意

某些响应状态码表示响应没有响应体（参阅下一章）。

# EditorConfig helps developers define and maintain consistent
# coding styles between different editors and IDEs
# editorconfig.org

root = true

[*]

indent_style = space
indent_size = 4

end_of_line = lf
charset = utf-8
trim_trailing_whitespace = true
insert_final_newline = true

spelling_languages = en-US

# Markdown files sometimes need trailing whitespaces.
[*.md]
trim_trailing_whitespace = false

 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express

 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express

 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,