## Conclusão

Vamos ver a mesma frase com o conteúdo cima:

> Versões modernas do Python tem suporte para **"código assíncrono"** usando algo chamado **"corrotinas"**, com sintaxe **`async` e `await`**.

Isso pode fazer mais sentido agora.

Tudo isso é o que deixa o FastAPI poderoso (através do Starlette) e que o faz ter uma performance impressionante.

* Any program, any code, **can only do things** when it is being **executed**. So, when there's a **process running**.
* The process can be **terminated** (or "killed") by you, or by the operating system. At that point, it stops running/being executed, and it can **no longer do things**.

### OpenAPI support

OpenAPI doesn't support a way to declare a *path parameter* to contain a *path* inside, as that could lead to scenarios that are difficult to test and define.

Nevertheless, you can still do it in **FastAPI**, using one of the internal tools from Starlette.

And the docs would still work, although not adding any documentation telling that the parameter should contain a path.

### Path convertor

## Mounting a sub-application

If you need to mount a sub-application (as described in [Sub Applications - Mounts](sub-applications.md){.internal-link target=_blank}) while also using a proxy with `root_path`, you can do it normally, as you would expect.

This is an advanced usage that you might not really need, but it's there in case you do.

## Include an `APIRouter` in another

The same way you can include an `APIRouter` in a `FastAPI` application, you can include an `APIRouter` in another `APIRouter` using:

```Python
router.include_router(other_router)
```

Notice that the variable `item` is one of the elements in the list `items`.

And still, the editor knows it is a `str`, and provides support for that.

#### Tuple and Set

You would do the same to declare `tuple`s and `set`s:

=== "Python 3.9+"

    ```Python hl_lines="1"
    {!> ../../../docs_src/python_types/tutorial007_py39.py!}
    ```

=== "Python 3.8+"

    But this example is still valid and it shows how to interact with the internal components.

We can also use this same approach to access the request body in an exception handler.

All we need to do is handle the request inside a `try`/`except` block:

```Python hl_lines="13  15"
{!../../../docs_src/custom_request_and_route/tutorial002.py!}
```

Isso é bastante similar ao caso do HTTP status code 200 (do 200 ao 299). Esses "200" status codes significam que, de algum modo, houve sucesso na requisição.

Os status codes na faixa dos 400 significam que houve um erro por parte do cliente.

Você se lembra de todos aqueles erros (e piadas) a respeito do "**404 Not Found**"?

## Use o `HTTPException`

### Apenas Python moderno

Tudo é baseado no padrão das declarações de **tipos do Python 3.8** (graças ao Pydantic). Nenhuma sintaxe nova para aprender. Apenas o padrão moderno do Python.

Se você precisa refrescar a memória rapidamente sobre como usar tipos do Python (mesmo que você não use o FastAPI), confira esse rápido tutorial: [Tipos do Python](python-types.md){.internal-link target=_blank}.

Você escreve Python padrão com tipos:

    file.read()
```

In neueren Versionen von Python gibt es auch einen **asynchronen Kontextmanager**. Sie würden ihn mit `async with` verwenden:

```Python
async with lifespan(app):
    await do_stuff()
```