{* ../../docs_src/query_params_str_validations/tutorial003_an_py310.py hl[10] *}

## Agregar expresiones regulares { #add-regular-expressions }

Puedes definir un <abbr title="Una expresión regular, regex o regexp es una secuencia de caracteres que define un patrón de búsqueda para strings.">expresión regular</abbr> `pattern` que el parámetro debe coincidir:

{* ../../docs_src/query_params_str_validations/tutorial004_an_py310.py hl[11] *}

    return (fromList instanceof RandomAccess)
        ? new TransformingRandomAccessList<>(fromList, function)
        : new TransformingSequentialList<>(fromList, function);
  }

  /**
   * Implementation of a sequential transforming list.
   *
   * @see Lists#transform
   */
  private static final class TransformingSequentialList<
          F extends @Nullable Object, T extends @Nullable Object>

    # Do some asynchronous stuff to create the burgers
    return burgers
```

...而不是 `def`:

```Python hl_lines="2"
# This is not asynchronous
def get_sequential_burgers(number: int):
    # Do some sequential stuff to create the burgers
    return burgers
```

使用 `async def`，Python 就知道在该函数中，它将遇上 `await`，并且它可以"暂停" ⏸ 执行该函数，直至执行其他操作 🔀 后回来。

当你想调用一个 `async def` 函数时，你必须"等待"它。因此，这不会起作用：

```Python

    return burgers
```

...`def`를 사용하는 대신:

```Python hl_lines="2"
# This is not asynchronous
def get_sequential_burgers(number: int):
    # Do some sequential stuff to create the burgers
    return burgers
```

`async def`를 사용하면, 파이썬은 해당 함수 내에서 `await` 표현에 주의해야한다는 사실과, 해당 함수의 실행을 "일시정지"⏸하고 다시 돌아오기 전까지 다른 작업을 수행🔀할 수 있다는 것을 알게됩니다.

- github.com/mitchellh/go-homedir: [v1.1.0](https://github.com/mitchellh/go-homedir/tree/v1.1.0)
- github.com/moby/sys/sequential: [v0.5.0](https://github.com/moby/sys/tree/sequential/v0.5.0)
- github.com/open-policy-agent/opa: [v0.67.1](https://github.com/open-policy-agent/opa/tree/v0.67.1)
- github.com/pelletier/go-toml: [v1.9.5](https://github.com/pelletier/go-toml/tree/v1.9.5)

* Recognize ca-central-1 region ([#38410](https://github.com/kubernetes/kubernetes/pull/38410), [@justinsb](https://github.com/justinsb))
* Add sequential allocator for device names. ([#38818](https://github.com/kubernetes/kubernetes/pull/38818), [@jsafrane](https://github.com/jsafrane))

#### Azure

* Fixes API compatibility issue with empty lists incorrectly returning a null `items` field instead of an empty array. ([#39834](https://github.com/kubernetes/kubernetes/pull/39834), [@liggitt](https://github.com/liggitt))
* AWS: Add sequential allocator for device names. ([#38818](https://github.com/kubernetes/kubernetes/pull/38818), [@jsafrane](https://github.com/jsafrane))

- Azure VMSS LoadBalancerBackendAddressPools updating has been improved with sequential-sync + concurrent-async requests. ([#88699](https://github.com/kubernetes/kubernetes/pull/88699), [@feiskyer](https://github.com/feiskyer)) [SIG Cloud Provider]

* Fixed a race condition in k8s.io/client-go/tools/cache.SharedInformer that could violate the sequential delivery guarantee and cause panics on shutdown in Kubernetes 1.8.* and 1.9.*. ([#59828](https://github.com/kubernetes/kubernetes/pull/59828), [@krousey](https://github.com/krousey))

        `train_step()`/`test_step()`/`predict_step()` methods, e.g. `if
        x.shape.rank == 1: x = tf.expand_dims(x, axis=-1)`. Functional models as
        well as Sequential models built with an explicit input shape are not
        affected.
    *   The methods `Model.to_yaml()` and `keras.models.model_from_yaml` have
        been replaced to raise a `RuntimeError` as they can be abused to cause