print(f"Hey {name}!")
```

El parámetro `name` está definido como `Optional[str]`, pero **no es opcional**, no puedes llamar a la función sin el parámetro:

```Python
say_hi()  # ¡Oh, no, esto lanza un error! 😱
```

El parámetro `name` **sigue siendo requerido** (no es *opcional*) porque no tiene un valor por defecto. Aun así, `name` acepta `None` como valor:

```Python

* `Field(primary_key=True)` informa ao SQLModel que o `id` é a **chave primária** no banco de dados SQL (você pode aprender mais sobre chaves primárias SQL na documentação do SQLModel).

* **`300 - 399`** son para "Redirección". Los responses con estos códigos de estado pueden o no tener un body, excepto `304`, "Not Modified", que no debe tener uno.
* **`400 - 499`** son para responses de "Error del Cliente". Este es el segundo tipo que probablemente más usarías.
    * Un ejemplo es `404`, para un response "Not Found".
    * Para errores genéricos del cliente, puedes usar simplemente `400`.

    response_class=JsonApiResponse,
    responses={500: {"description": "Error", "model": JsonApiError}},
)
async def a():
    pass


@app.get("/b", responses={204: {"description": "No Content"}})
async def b():
    pass  # pragma: no cover


client = TestClient(app)


def test_get_response():
    response = client.get("/a")
    assert response.status_code == 204, response.text

            final RuleManager ruleManager = SingletonLaContainer.getComponent(RuleManager.class);
            final Rule rule = ruleManager.getRule(responseData);
            if (rule == null) {
                logger.warn("No matching url rule for url='{}'", url);
            } else {
                responseData.setRuleId(rule.getRuleId());
                final ResponseProcessor responseProcessor = rule.getResponseProcessor();

    }
  }


  public void testScanFromFile_fileNotExists() throws IOException {
    ClassLoader classLoader = ClassPathTest.class.getClassLoader();
    assertThat(
            new ClassPath.LocationInfo(new File("no/such/file/anywhere"), classLoader)
                .scanResources())
        .isEmpty();
  }

  @AndroidIncompatible // ClassPath is documented as not supporting Android

volume will be bound existingClaim: "" ## minio data Persistent Volume Storage Class ## If defined, storageClassName: <storageClass> ## If set to "-", storageClassName: "", which disables dynamic provisioning ## If undefined (the default) or set to null, no storageClassName spec is ## set, choosing the default provisioner. (gp2 on AWS, standard on ## GKE, AWS & OpenStack) ## ## Storage class of PV to bind. By default it looks for standard storage class. ## If the PV uses a different storage class, specify...

$ echo "Hello $Env:MY_NAME"

Hello Wade Wilson
```

</div>

////

## Ler Variáveis de Ambiente no Python { #read-env-vars-in-python }

Você também pode criar variáveis de ambiente **fora** do Python, no terminal (ou com qualquer outro método) e depois **lê-las no Python**.

Por exemplo, você poderia ter um arquivo `main.py` com:

```Python hl_lines="3"
import os

volume will be bound existingClaim: "" ## minio data Persistent Volume Storage Class ## If defined, storageClassName: <storageClass> ## If set to "-", storageClassName: "", which disables dynamic provisioning ## If undefined (the default) or set to null, no storageClassName spec is ## set, choosing the default provisioner. (gp2 on AWS, standard on ## GKE, AWS & OpenStack) ## ## Storage class of PV to bind. By default it looks for standard storage class. ## If the PV uses a different storage class, specify...

volume will be bound existingClaim: "" ## minio data Persistent Volume Storage Class ## If defined, storageClassName: <storageClass> ## If set to "-", storageClassName: "", which disables dynamic provisioning ## If undefined (the default) or set to null, no storageClassName spec is ## set, choosing the default provisioner. (gp2 on AWS, standard on ## GKE, AWS & OpenStack) ## ## Storage class of PV to bind. By default it looks for standard storage class. ## If the PV uses a different storage class, specify...