* Oggetti `datetime`.
    * Oggetti `UUID`.
    * Modelli del database.
    * ...e molto di più.
* Generazione di una documentazione dell'API interattiva, con scelta dell'interfaccia grafica:
    * Swagger UI.
    * ReDoc.

---

Tornando al precedente esempio, **FastAPI**:

* Validerà che esiste un `item_id` nel percorso delle richieste `GET` e `PUT`.

    We are not restricted to having only one dependency that can return that type of data.

## Other models

You can now get the current user directly in the *path operation functions* and deal with the security mechanisms at the **Dependency Injection** level, using `Depends`.

And you can use any model or data for the security requirements (in this case, a Pydantic model `User`).

At the same point, you try to trigger the autocomplete with `Ctrl+Space` and you see:

<img src="/img/python-types/image02.png">

With that, you can scroll, seeing the options, until you find the one that "rings a bell":

<img src="/img/python-types/image03.png">

## More motivation

Check this function, it already has type hints:

```Python hl_lines="1"
{!../../../docs_src/python_types/tutorial003.py!}
```

**Corrotina** é apenas um jeito bonitinho para a coisa que é retornada de uma função `async def`. O Python sabe que é uma função que pode começar e terminar em algum ponto, mas que pode ser pausada internamente também, sempre que tiver um `await` dentro dela.

Mas toda essa funcionalidade de código assíncrono com `async` e `await` é muitas vezes resumida como "corrotina". É comparável ao principal recurso chave do Go, a "Gorotina".

## Conclusão

Dans les versions précédentes de Javascript NodeJS / Navigateur, vous auriez utilisé des "callbacks". Menant potentiellement à ce que l'on appelle <a href="http://callbackhell.com/" class="external-link" target="_blank">le "callback hell"</a>.


## Coroutines

# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to
# deal in the Software without restriction, including without limitation the
# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
# sell copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:

`RequestValidationError` é uma subclasse do <a href="https://docs.pydantic.dev/latest/#error-handling" class="external-link" target="_blank">`ValidationError`</a> existente no Pydantic.

**FastAPI** faz uso dele para que você veja o erro no seu log, caso você utilize um modelo de Pydantic em `response_model`, e seus dados tenham erro.

"*Nós trocamos nossas **APIs** por **FastAPI** [...] Acredito que vocês gostarão dele [...]*"

There are many situations in which you need to notify an error to a client that is using your API.

This client could be a browser with a frontend, a code from someone else, an IoT device, etc.

You could need to tell the client that:

* The client doesn't have enough privileges for that operation.
* The client doesn't have access to that resource.
* The item the client was trying to access doesn't exist.
* etc.

In many frameworks and systems just handling security and authentication takes a big amount of effort and code (in many cases it can be 50% or more of all the code written).

**FastAPI** provides several tools to help you deal with **Security** easily, rapidly, in a standard way, without having to study and learn all the security specifications.

But first, let's check some small concepts.

## In a hurry?