!!! note "Observação"
    O FastAPI saberá que o valor de `q` não é obrigatório por causa do valor padrão `= None`.

    O `Union` em `Union[str, None]` não é usado pelo FastAPI, mas permitirá que seu editor lhe dê um melhor suporte e detecte erros.

## Validação adicional

Nós iremos forçar que mesmo o parâmetro `q` seja opcional, sempre que informado, **seu tamanho não exceda 50 caracteres**.

### Importe `Query`

In order to make changes to Gradle, you'll need:

* A [Java Development Kit](http://jdk.java.net/) (JDK) **version 11**. Fixed version is required to use [remote cache](#remote-build-cache). 
* A text editor or IDE. We use and recommend [IntelliJ IDEA CE](http://www.jetbrains.com/idea/).  IntelliJ Ultimate will also work. You'll need IntelliJ 2021.2.2 or newer.
* [git](https://git-scm.com/) and a [GitHub account](https://github.com/join).

エディターがどのように役立つかを以下に示します:

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

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

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

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

```

</div>

Es wird **ausdrücklich empfohlen**, dass Sie den Code schreiben oder kopieren, ihn bearbeiten und lokal ausführen.

Die Verwendung in Ihrem eigenen Editor zeigt Ihnen die Vorteile von FastAPI am besten, wenn Sie sehen, wie wenig Code Sie schreiben müssen, all die Typprüfungen, die automatische Vervollständigung usw.

---

## FastAPI installieren

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

...a:

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

...e osserva come il tuo editor di testo autocompleterà gli attributi e sarà in grado di riconoscere i loro tipi:

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

    Diese Funktionen existieren (statt die Klassen direkt zu verwenden), damit Ihr Editor keine Fehlermeldungen über ihre Typen ausgibt.

```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>

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

In this case, `item_id` is declared to be an `int`.

!!! check
    This will give you editor support inside of your function, with error checks, completion, etc.

## Data <abbr title="also known as: serialization, parsing, marshalling">conversion</abbr>

...de:

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

...para:

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

...e veja como seu editor irá auto-completar os atributos e saberá os tipos:

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

...from:

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

...to:

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

...and see how your editor will auto-complete the attributes and know their types:

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