## `async` and `await`

Modern versions of Python have a very intuitive way to define asynchronous code. This makes it look just like normal "sequential" code and do the "awaiting" for you at the right moments.

When there is an operation that will require waiting before giving the results and has support for these new Python features, you can code it like:

```Python
burgers = await get_burgers(2)
```

もちろん、これは最適な方法ではありませんし、本番環境で使うことはないでしょう。

本番環境では、上記の方法のいずれかの選択肢を採用することになるでしょう。

しかし、これはWebSocketのサーバーサイドに焦点を当て、実用的な例を示す最も簡単な方法です。

```Python hl_lines="2  6-38  41-43"
{!../../docs_src/websockets/tutorial001.py!}
```

## `websocket` を作成する

**FastAPI** アプリケーションで、`websocket` を作成します。

```Python hl_lines="1  46-47"
{!../../docs_src/websockets/tutorial001.py!}
```

/// note | "技術詳細"

## Plantilla de FastAPI Full Stack - Tecnología y Características

- ⚡ [**FastAPI**](https://fastapi.tiangolo.com) para el backend API en Python.
    - 🧰 [SQLModel](https://sqlmodel.tiangolo.com) para las interacciones con la base de datos SQL en Python (ORM).
    - 🔍 [Pydantic](https://docs.pydantic.dev), utilizado por FastAPI, para la validación de datos y la gestión de configuraciones.

Primeiro, você tem que importá-lo:

```Python hl_lines="4"
{!../../docs_src/body_fields/tutorial001.py!}
```

/// warning | "Aviso"

Note que `Field` é importado diretamente do `pydantic`, não do `fastapi` como todo o resto (`Query`, `Path`, `Body`, etc).

///

## Declare atributos do modelo

Você pode então utilizar `Field` com atributos do modelo:

```Python hl_lines="11-14"

      - name: Checkout repository
        if: ${{ github.event_name == 'push' }}
        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
      - name: Build binary and run python tests on nightly for all python versions
        shell: bash
        run: |
          is_nightly=0 && tf_project_name='tf_ci_ext' && ${{ github.event_name == 'schedule' }} && is_nightly=1 && tf_project_name='tf_nightly_ci_ext'

    attribute to access the raw standard Python file (blocking, not async), useful and
    needed for non-async code.

    Read more about it in the
    [FastAPI docs for Request Files](https://fastapi.tiangolo.com/tutorial/request-files/).

    ## Example

    ```python
    from typing import Annotated

    from fastapi import FastAPI, File, UploadFile

When you raise an exception, as would happen with normal Python, the rest of the execution is aborted. This way you can raise these exceptions from anywhere in the code to abort a request and show the error to the client.

You can use:

* `HTTPException`
* `WebSocketException`

These exceptions can be imported directly from `fastapi`:

```python
from fastapi import HTTPException, WebSocketException
```

```

</div>

/// note

The command `uvicorn main:app` refers to:

* `main`: the file `main.py` (the Python "module").
* `app`: the object created inside of `main.py` with the line `app = FastAPI()`.

It is equivalent to:

```Python
from main import app
```

///

```Python hl_lines="3  6-8"
{!../../docs_src/sub_applications/tutorial001.py!}
```

### Sub-aplicação

Em seguida, crie sua sub-aplicação e suas *operações de rota*.

Essa sub-aplicação é apenas outra aplicação FastAPI padrão, mas esta é a que será "montada":

```Python hl_lines="11  14-16"
{!../../docs_src/sub_applications/tutorial001.py!}
```

    * Dann gibt es die von der entsprechenden *Pfadoperation* generierte `response` zurück.
* Sie können die `response` dann weiter modifizieren, bevor Sie sie zurückgeben.

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

/// tip | "Tipp"