With `data.items()` we get an <abbr title="Something we can iterate on with a for loop, like a list, set, etc.">iterable object</abbr> with tuples containing the key and value for each dictionary item.

We convert this iterable object into a proper `list` with `list(data.items())`.

`Optional[Something]` ist tatsächlich eine Abkürzung für `Union[Something, None]`, diese beiden sind äquivalent.

Das bedeutet auch, dass Sie in Python 3.10 `Something | None` verwenden können:

//// tab | Python 3.10+

```Python hl_lines="1"
{!> ../../docs_src/python_types/tutorial009_py310.py!}
```

**FastAPI** inclui vários middlewares para casos de uso comuns, veremos a seguir como usá-los.

/// note | Detalhes Técnicos

Para o próximo exemplo, você também poderia usar `from starlette.middleware.something import SomethingMiddleware`.

**FastAPI** fornece vários middlewares em `fastapi.middleware` apenas como uma conveniência para você, o desenvolvedor. Mas a maioria dos middlewares disponíveis vem diretamente do Starlette.

///

                            + " (" + repository.getUrl() + ")");
        }

        if (file == null) {
            // TODO throw something instead?
            return true;
        }

        Date lastCheckDate;

        if (file.exists()) {
            lastCheckDate = new Date(file.lastModified());
        } else {

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[13] *}

Let's focus on the parameters declared:

* Even though this function is a dependency ("dependable") itself, it also declares another dependency (it "depends" on something else).
    * It depends on the `query_extractor`, and assigns the value returned by it to the parameter `q`.
* It also declares an optional `last_query` cookie, as a `str`.

**FastAPI** incluye varios middlewares para casos de uso común, veremos a continuación cómo usarlos.

/// note | Detalles Técnicos

Para los próximos ejemplos, también podrías usar `from starlette.middleware.something import SomethingMiddleware`.

**FastAPI** proporciona varios middlewares en `fastapi.middleware` solo como una conveniencia para ti, el desarrollador. Pero la mayoría de los middlewares disponibles provienen directamente de Starlette.

**FastAPI** enthält mehrere Middlewares für gängige Anwendungsfälle. Wir werden als Nächstes sehen, wie man sie verwendet.

/// note | Technische Details

Für die nächsten Beispiele könnten Sie auch `from starlette.middleware.something import SomethingMiddleware` verwenden.

**FastAPI** bietet mehrere Middlewares via `fastapi.middleware` an, als Annehmlichkeit für Sie, den Entwickler. Die meisten verfügbaren Middlewares kommen aber direkt von Starlette.

///

`Optional[Something]` is actually a shortcut for `Union[Something, None]`, they are equivalent.

This also means that in Python 3.10, you can use `Something | None`:

//// tab | Python 3.10+

```Python hl_lines="1"
{!> ../../docs_src/python_types/tutorial009_py310.py!}
```

////

    * An example is `404`, for a "Not Found" response.
    * For generic errors from the client, you can just use `400`.
* `500 - 599` are for server errors. You almost never use them directly. When something goes wrong at some part in your application code, or server, it will automatically return one of these status codes.

/// tip

        VersionRange range = artifact.getVersionRange();

        // For some reason with the introduction of MNG-1577 we have the case in Yoko where a depMan section has
        // something like the following:
        //
        // <dependencyManagement>
        //     <dependencies>
        //         <!--  Yoko modules -->
        //         <dependency>