```Python hl_lines="3"
{!../../docs_src/first_steps/tutorial001.py!}
```

In diesem Beispiel ist die Variable `app` eine „Instanz“ der Klasse `FastAPI`.

Dies wird der Hauptinteraktionspunkt für die Erstellung all Ihrer APIs sein.

Die Variable `app` ist dieselbe, auf die sich der Befehl `uvicorn` bezieht:

<div class="termy">

```console
$ uvicorn main:app --reload

    }

    /*
     * These gymnastics are a little confusing. Basically this class has neither legacy nor
     * non-legacy behavior; it just needs to let the behavior of the backing converter shine
     * through. So, we override the correctedDo* methods, after which the do* methods should never
     * be reached.
     */

    @Override
    protected A doForward(B b) {
      throw new AssertionError();

Tại cùng một điểm, bạn thử kích hoạt autocomplete với `Ctrl+Space` và bạn thấy:

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

Với cái đó, bạn có thể cuộn, nhìn thấy các lựa chọn, cho đến khi bạn tìm thấy một "tiếng chuông":

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

## Động lực nhiều hơn

Kiểm tra hàm này, nó đã có gợi ý kiểu dữ liệu:

```Python hl_lines="1"

import jcifs.spnego.SpnegoException;
import jcifs.spnego.SpnegoToken;
import jcifs.util.Hexdump;


/**
 * This class used to wrap a {@link SSPContext} to provide SPNEGO feature.
 * 
 * @author Shun
 *
 */
class SpnegoContext implements SSPContext {

    private static final Logger log = LoggerFactory.getLogger(SpnegoContext.class);

    private static ASN1ObjectIdentifier SPNEGO_MECH_OID;

    static {

test:rbe_base --test_env=USER=anon

# TODO(kanglan): Check if we want to merge rbe_linux into rbe_linux_cpu.
build:rbe_linux --config=rbe_base
build:rbe_linux --action_env=PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/local/go/bin"
# Non-rbe settings we should include because we do not run configure
build:rbe_linux --config=avx_linux
# TODO(gunan): Check why we need this specified in rbe, but not in other builds.

  // It is necessary here because otherwise the builder() method
  // would be inherited from the emulated ImmutableSet.
  // TODO(cpovirk): should we be including other methods from the shim here and
  // in ImmutableSortedMap?
  @Deprecated
  public static <E> ImmutableSortedSet.Builder<E> builder() {
    throw new UnsupportedOperationException();
  }

	github.com/quic-go/qpack v0.5.1 // indirect
	github.com/rivo/uniseg v0.4.6 // indirect
	github.com/russross/blackfriday/v2 v2.1.0 // indirect
	github.com/sagikazarmark/locafero v0.4.0 // indirect
	github.com/sagikazarmark/slog-shim v0.1.0 // indirect
	github.com/shopspring/decimal v1.4.0 // indirect
	github.com/sirupsen/logrus v1.9.3 // indirect
	github.com/sourcegraph/conc v0.3.0 // indirect
	github.com/spf13/afero v1.11.0 // indirect

Die `response_class` wird dann nur zur Dokumentation der OpenAPI-Pfadoperation* verwendet, Ihre `Response` wird jedoch unverändert verwendet.

#### Eine `HTMLResponse` direkt zurückgeben

Es könnte zum Beispiel so etwas sein:

```Python hl_lines="7  21  23"
{!../../docs_src/custom_response/tutorial004.py!}
```

```

Esto significa: la variable `items` es una `list` y cada uno de los ítems en esta lista es un `str`.

Con esta declaración tu editor puede proveerte soporte inclusive mientras está procesando ítems de la lista.

Sin tipos el auto-completado en este tipo de estructura es casi imposible de lograr:

<img src="https://fastapi.tiangolo.com/img/python-types/image05.png">

### Soporte de OpenAPI

OpenAPI no soporta una manera de declarar un *parámetro de path* que contenga un path, dado que esto podría llevar a escenarios que son difíciles de probar y definir.

Sin embargo, lo puedes hacer en **FastAPI** usando una de las herramientas internas de Starlette.

La documentación seguirá funcionando, aunque no añadirá ninguna información diciendo que el parámetro debería contener un path.