///

## Importez le `BaseModel` de Pydantic

Commencez par importer la classe `BaseModel` du module `pydantic` :

{* ../../docs_src/body/tutorial001.py hl[4] *}

## Créez votre modèle de données

Déclarez ensuite votre modèle de données en tant que classe qui hérite de `BaseModel`.

Utilisez les types Python standard pour tous les attributs :

    hashed_password = user_dict["hashed_password"],
)
```

/// info | Información

Para una explicación más completa de `**user_dict` revisa en [la documentación para **Extra Models**](../extra-models.md#about-user_indict){.internal-link target=_blank}.

///

## Devolver el token

El response del endpoint `token` debe ser un objeto JSON.

Using this same trick, you could use a Pydantic model to define the JSON Schema that is then included in the custom OpenAPI schema section for the *path operation*.

And you could do this even if the data type in the request is not JSON.

以下のように:

{* ../../docs_src/body_nested_models/tutorial008.py hl[15] *}

## あらゆる場所でのエディタサポート

エディタのサポートもどこでも受けることができます。

以下のようにリストの中の項目でも:

<img src="https://fastapi.tiangolo.com/img/tutorial/body-nested-models/image01.png">

Pydanticモデルではなく、`dict`を直接使用している場合はこのようなエディタのサポートは得られません。

しかし、それらについて心配する必要はありません。入力された辞書は自動的に変換され、出力も自動的にJSONに変換されます。

## 任意の`dict`のボディ

また、ある型のキーと別の型の値を持つ`dict`としてボディを宣言することもできます。

* data validation
* data serialization
* data documentation, etc.

This works the same way as with Pydantic models. And it is actually achieved in the same way underneath, using Pydantic.

/// info

Keep in mind that dataclasses can't do everything Pydantic models can do.

So, you might still need to use Pydantic models.

Podrías cargarlo en el nivel superior del módulo/archivo, pero eso también significaría que **cargaría el modelo** incluso si solo estás ejecutando una simple prueba automatizada, entonces esa prueba sería **lenta** porque tendría que esperar a que el modelo se cargue antes de poder ejecutar una parte independiente del código.

/**
 * A test which demonstrates maven's recursive inheritance where
 * a distinct value is taken from each parent contributing to
 * the final model of the project being assembled. There is no
 * overriding going on amongst the models being used in this test:
 * each model in the lineage is providing a value that is not present
 * anywhere else in the lineage. We are just making sure that values

## Use Case { #use-case }

Let's start with an example **use case** and then see how to solve it with this.

Let's imagine that you have some **machine learning models** that you want to use to handle requests. 🤖

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

The `app_name` would be `"ChimichangApp"`.

And the `items_per_user` would keep its default value of `50`.

## Settings in another module { #settings-in-another-module }

You could put those settings in another module file as you saw in [Bigger Applications - Multiple Files](../tutorial/bigger-applications.md){.internal-link target=_blank}.

For example, you could have a file `config.py` with:

   <span style="background-color:#007166"><font color="#D3D7CF"> module </font></span>  🐍 main.py

     <span style="background-color:#007166"><font color="#D3D7CF"> code </font></span>  Importing the FastAPI app object from the module with
             the following code: