Instead of that, by being an "asynchronous" system, once finished, the task can wait in line a little bit (some microseconds) for the computer / program to finish whatever it went to do, and then come back to take the results and continue working with them.

For this, use the Python standard module <a href="https://docs.python.org/3/library/secrets.html" class="external-link" target="_blank">`secrets`</a> to check the username and password.

`secrets.compare_digest()` needs to take `bytes` or a `str` that only contains ASCII characters (the ones in English), this means it wouldn't work with characters like `á`, as in `Sebastián`.

Or it might be the case that you just prefer to take other courses because they adapt better to your learning style.

如果你已经安装 Typer CLI ，则可以使用以下命令安装自动补全功能：

<div class="termy">

```console
$ typer --install-completion

zsh completion installed in /home/user/.bashrc.
Completion will take effect once you restart the terminal.
```

</div>

### 文档架构

文档使用 <a href="https://www.mkdocs.org/" class="external-link" target="_blank">MkDocs</a> 生成。

在 `./scripts/docs.py` 中还有额外工具 / 脚本来处理翻译。

<a href="https://www.codacy.com/?utm_source=github&utm_medium=sponsors&utm_id=pioneers" target="_blank" title="Take code reviews from hours to minutes"><img src="https://fastapi.tiangolo.com/img/sponsors/codacy.png"></a>

<!-- /sponsors -->

```json
{"message": "Hello World"}
```

...this response will return:

```json
{
  "message": "Hello World"
}
```

Of course, you will probably find much better ways to take advantage of this than formatting JSON. 😉

## Default response class

When creating a **FastAPI** class instance or an `APIRouter` you can specify which response class to use by default.

Each of those response `dict`s can have a key `model`, containing a Pydantic model, just like `response_model`.

**FastAPI** will take that model, generate its JSON Schema and include it in the correct place in OpenAPI.

For example, to declare another response with a status code `404` and a Pydantic model `Message`, you can write:

```Python hl_lines="18  22"

  - url: https://www.svix.com/
    title: Svix - Webhooks as a service
    img: https://fastapi.tiangolo.com/img/sponsors/svix.svg
  - url: https://www.codacy.com/?utm_source=github&utm_medium=sponsors&utm_id=pioneers
    title: Take code reviews from hours to minutes
    img: https://fastapi.tiangolo.com/img/sponsors/codacy.png
bronze:
  - url: https://www.exoflare.com/open-source/?utm_source=FastAPI&utm_campaign=open_source

The same models are shared among requests, so, it's not one model per request, or one per user or something similar.

Let's imagine that loading the model can **take quite some time**, because it has to read a lot of **data from disk**. So you don't want to do it for every request.

                    for param in parameters
                    if param.get("required")
                }
                # Make sure required definitions of the same parameter take precedence
                # over non-required definitions
                all_parameters.update(required_parameters)
                operation["parameters"] = list(all_parameters.values())