```Python hl_lines="6-7"
{!../../../docs_src/path_params/tutorial001.py!}
```

El valor del parámetro de path `item_id` será pasado a tu función como el argumento `item_id`.

Entonces, si corres este ejemplo y vas a <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a>, verás una respuesta de:

```JSON
{"item_id":"foo"}
```

Par exemple, il était clair que l'idéal était de se baser sur les annotations de type Python standard.

De plus, la meilleure approche était d'utiliser des normes déjà existantes.

Ainsi, avant même de commencer à coder **FastAPI**, j'ai passé plusieurs mois à étudier les spécifications d'OpenAPI, JSON Schema, OAuth2, etc. Comprendre leurs relations, leurs similarités et leurs différences.

	// InsecureSkipVerify skips client verification the server's certificate chain and host name.
	InsecureSkipVerify bool

	// XDSSAN is the expected Subject Alternative Name of the XDS server
	XDSSAN string

	// Plaintext forces plain text communication (for talking to port 15010)
	Plaintext bool

	// GCP project number or ID to use for XDS calls, if any.
	GCPProject string

	// Istiod address. For MCP may be different than Xds.

    * Si estás comparando Uvicorn, compáralo con los servidores de aplicaciones Daphne, Hypercorn, uWSGI, etc.
* **Starlette**:
    * Tendrá el siguiente mejor desempeño, después de Uvicorn. De hecho, Starlette usa Uvicorn para correr. Por lo tanto, probablemente sólo pueda volverse "más lento" que Uvicorn al tener que ejecutar más código.

        # GPU:
        *manylinux*)     LARGEST_OK_SIZE=580 ;;
        # Unknown:
        *)
            echo "The wheel's name is in an unknown format."
            exit 1
            ;;
    esac
    # >&3 forces output in bats even if the test passes. See
    # https://bats-core.readthedocs.io/en/stable/writing-tests.html#printing-to-the-terminal
    echo "# Size of $TF_WHEEL is $WHEEL_MEGABYTES / $LARGEST_OK_SIZE megabytes." >&3

      }
    }

    throw new IllegalArgumentException(
        Platform.format("key %s not found in entries %s", newEntry.getKey(), expected));
  }

  /**
   * Wrapper for {@link Map#get(Object)} that forces the caller to pass in a key of the same type as
   * the map. Besides being slightly shorter than code that uses {@link #getMap()}, it also ensures
   * that callers don't pass an {@link Entry} by mistake.
   */

When deploying applications you will probably want to have some **replication of processes** to take advantage of **multiple cores** and to be able to handle more requests.

As you saw in the previous chapter about [Deployment Concepts](concepts.md){.internal-link target=_blank}, there are multiple strategies you can use.

      }
    }

    throw new IllegalArgumentException(
        Platform.format("key %s not found in entries %s", newEntry.getKey(), expected));
  }

  /**
   * Wrapper for {@link Map#get(Object)} that forces the caller to pass in a key of the same type as
   * the map. Besides being slightly shorter than code that uses {@link #getMap()}, it also ensures
   * that callers don't pass an {@link Entry} by mistake.
   */

    `float16` for acceleration on Volta and Turing Tensor Cores. This feature
    can be enabled by wrapping an optimizer class with
    `tf.train.experimental.enable_mixed_precision_graph_rewrite()`.
*   Add environment variable `TF_CUDNN_DETERMINISTIC`. Setting to "true" or "1"
    forces the selection of deterministic cuDNN convolution and max-pooling

# Primeros pasos

Un archivo muy simple de FastAPI podría verse así:

```Python
{!../../../docs_src/first_steps/tutorial001.py!}
```

Copia eso a un archivo `main.py`.

Corre el servidor en vivo:

<div class="termy">

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

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)