"input": "plumbus"
        }
    ]
}
```

## Summary { #summary }

You can use **Pydantic models** to declare **query parameters** in **FastAPI**. 😎

/// tip

Spoiler alert: you can also use Pydantic models to declare cookies and headers, but you will read about that later in the tutorial. 🤫

And then, right after the `yield`, we unload the model. This code will be executed **after** the application **finishes handling requests**, right before the *shutdown*. This could, for example, release resources like memory or a GPU.

/// tip

The `shutdown` would happen when you are **stopping** the application.

Maybe you need to start a new version, or you just got tired of running it. 🤷

///

### Lifespan function { #lifespan-function }

/// tip | Dica

O `shutdown` aconteceria quando você estivesse **encerrando** a aplicação.

Talvez você precise iniciar uma nova versão, ou apenas cansou de executá-la. 🤷

///

### Função lifespan { #lifespan-function }

* Deep Learning: Deep Learning (do not translate to "Aprendizaje Profundo")
* callback hell: callback hell (do not translate to "infierno de callbacks")
* tip: Consejo (do not translate to "tip")
* check: Revisa (do not translate to "chequea" or "comprobación)
* Cross-Origin Resource Sharing: Cross-Origin Resource Sharing (do not translate to "Compartición de Recursos de Origen Cruzado")

Ahí puedes establecer:

* El "ID del Ítem", usado en el path.
* El "Token" usado como un parámetro query.

/// tip | Consejo

Nota que el query `token` será manejado por una dependencia.

///

Con eso puedes conectar el WebSocket y luego enviar y recibir mensajes:

<img src="/img/tutorial/websockets/image05.png">

Write simple `assert` statements with the standard Python expressions that you need to check (again, standard `pytest`).

{* ../../docs_src/app_testing/tutorial001_py39.py hl[2,12,15:18] *}

/// tip

Notice that the testing functions are normal `def`, not `async def`.

And the calls to the client are also normal calls, not using `await`.

This allows you to use `pytest` directly without complications.

///

### `///` admonitions

1) Keep the admonition keyword in English (do not translate `note`, `tip`, etc.).
2) Many Traditional Chinese docs currently omit titles in `///` blocks; that is OK.
3) If a generic title is present, prefer these canonical titles:

- `/// note | 注意`

Notes:

你应该在添加了所有 *路径操作* 之后执行此操作。

{* ../../docs_src/path_operation_advanced_configuration/tutorial002.py hl[2,12,13,14,15,16,17,18,19,20,21,24] *}

/// tip

如果你手动调用 `app.openapi()`，你应该在此之前更新 `operationId`。

///

/// warning

如果你这样做，务必确保你的每个 *路径操作函数* 的名字唯一。

即使它们在不同的模块中（Python 文件）。

///

## 从 OpenAPI 中排除

Помните, что когда вы импортируете `Query`, `Path` и другое из `fastapi`, это фактически функции, которые возвращают специальные классы.

///

/// tip | Подсказка

Обратите внимание, что каждый атрибут модели с типом, значением по умолчанию и `Field` имеет ту же структуру, что и параметр *функции обработки пути* с `Field` вместо `Path`, `Query` и `Body`.

///

# 환경 변수

/// tip | 팁

만약 "환경 변수"가 무엇이고, 어떻게 사용하는지 알고 계시다면, 이 챕터를 스킵하셔도 좋습니다.

///

환경 변수는 파이썬 코드의 **바깥**인, **운영 체제**에 존재하는 변수입니다. 파이썬 코드나 다른 프로그램에서 읽을 수 있습니다.

환경 변수는 애플리케이션 **설정**을 처리하거나, 파이썬의 **설치** 과정의 일부로 유용합니다.

## 환경 변수를 만들고 사용하기

파이썬 없이도, **셸 (터미널)** 에서 환경 변수를 **생성** 하고 사용할 수 있습니다.

//// tab | Linux, macOS, Windows Bash

<div class="termy">

```console
// You could create an env var MY_NAME with