* در <a href="https://code.visualstudio.com/" class="external-link" target="_blank">Visual Studio Code</a>:

![editor support](https://fastapi.tiangolo.com/img/vscode-completion.png)

* در <a href="https://www.jetbrains.com/pycharm/" class="external-link" target="_blank">PyCharm</a>:

![editor support](https://fastapi.tiangolo.com/img/pycharm-completion.png)

...van:

```Python
        ... "item_name": item.name ...
```

...naar:

```Python
        ... "item_price": item.price ...
```

...en zie hoe je editor de attributen automatisch invult en hun types herkent:

![editor support](https://fastapi.tiangolo.com/img/vscode-completion.png)

These functions are there (instead of just using the classes directly) so that your editor doesn't mark errors about their types.

That way you can use your normal editor and coding tools without having to add custom configurations to disregard those errors.

Todo el proceso que aplicaba a los parámetros de path también aplica a los parámetros de query:

* Soporte del editor (obviamente)
* <abbr title="convertir el string que viene de un HTTP request a datos de Python">"Parsing"</abbr> de datos
* Validación de datos
* Documentación automática

## Configuraciones por defecto

E ele gera _schemas_ OpenAPI.

É assim como funciona no Flask, Starlette, Responder etc.

Mas então, nós temos novamente o problema de ter uma micro-sintaxe, dentro de uma string Python (um grande YAML).

O editor não poderá ajudar muito com isso. E se nós modificarmos os parâmetros dos _schemas_ do Marshmallow e esquecer de modificar também aquela _docstring_ YAML, o _schema_ gerado pode ficar obsoleto.

/// info

/// note

FastAPI will know that the value of `q` is not required because of the default value `= None`.

The `Union` in `Union[str, None]` will allow your editor to give you better support and detect errors.

///

## Additional validation

We are going to enforce that even though `q` is optional, whenever it is provided, **its length doesn't exceed 50 characters**.

Estas funções são assim (ao invés de apenas usar as classes diretamente) para que seu editor não acuse erros sobre seus tipos.

Dessa maneira você pode user seu editor e ferramentas de desenvolvimento sem precisar adicionar configurações customizadas para ignorar estes erros.

```Python hl_lines="7"
{!../../docs_src/path_params/tutorial002.py!}
```

In diesem Fall wird `item_id` als `int` deklariert, also als Ganzzahl.

/// check

Dadurch erhalten Sie Editor-Unterstützung innerhalb Ihrer Funktion, mit Fehlerprüfungen, Codevervollständigung, usw.

///

## Daten-<abbr title="Auch bekannt als: Serialisierung, Parsen, Marshalling">Konversion</abbr>

* dans <a href="https://code.visualstudio.com/" class="external-link" target="_blank">Visual Studio Code</a>:

![editor support](https://fastapi.tiangolo.com/img/vscode-completion.png)

* dans <a href="https://www.jetbrains.com/pycharm/" class="external-link" target="_blank">PyCharm</a>:

![editor support](https://fastapi.tiangolo.com/img/pycharm-completion.png)

Up to now, you have been using common data types, like:

* `int`
* `float`
* `str`
* `bool`

But you can also use more complex data types.

And you will still have the same features as seen up to now:

* Great editor support.
* Data conversion from incoming requests.
* Data conversion for response data.
* Data validation.
* Automatic annotation and documentation.

## Other data types