Variáveis de ambiente podem ser úteis para lidar com **configurações** do aplicativo, como parte da **instalação** do Python, etc.

## Criar e Usar Variáveis de Ambiente { #create-and-use-env-vars }

Você pode **criar** e usar variáveis de ambiente no **shell (terminal)**, sem precisar do Python:

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```console

    * `description`: ein `str` mit einer kurzen Beschreibung für die externe Dokumentation.
    * `url` (**erforderlich**): ein `str` mit der URL für die externe Dokumentation.

### Metadaten für Tags erstellen { #create-metadata-for-tags }

Versuchen wir es mit einem Beispiel mit Tags für `users` und `items`.

Erstellen Sie Metadaten für Ihre Tags und übergeben Sie diese an den Parameter `openapi_tags`:

    * `description`: un `str` con una breve descripción para la documentación externa.
    * `url` (**requerido**): un `str` con la URL para la documentación externa.

### Crear metadata para etiquetas { #create-metadata-for-tags }

Probemos eso en un ejemplo con etiquetas para `users` y `items`.

Crea metadata para tus etiquetas y pásala al parámetro `openapi_tags`:

{* ../../docs_src/metadata/tutorial004_py39.py hl[3:16,18] *}

    private Proxy proxy;

    private List<ArtifactRepository> mirroredRepositories = Collections.emptyList();

    private boolean blocked;

    public MavenArtifactRepository() {}

    /**
     * Create a remote download repository.
     *
     * @param id        the unique identifier of the repository
     * @param url       the URL of the repository
     * @param layout    the layout of the repository

Las variables de entorno pueden ser útiles para manejar **configuraciones** de aplicaciones, como parte de la **instalación** de Python, etc.

## Crear y Usar Variables de Entorno { #create-and-use-env-vars }

Puedes **crear** y usar variables de entorno en la **shell (terminal)**, sin necesidad de Python:

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```console

						}
					}
					association.Error = association.DB.Session(&Session{
						NewDB: true,
					}).Model(child.Interface()).Create(mapv.Interface()).Error
				case schema.Many2Many:
					association.Error = association.DB.Session(&Session{
						NewDB: true,
					}).Model(child.Interface()).Create(mapv.Interface()).Error

					for _, key := range mapv.MapKeys() {
						k := strings.ToLower(key.String())

        } catch (ResourceDoesNotExistException e) {
            getLogger()
                    .info(metadata + " could not be found on repository: " + remoteRepository.getId()
                            + ", so will be created");

            // delete the local copy so the old details aren't used.
            if (file.exists()) {
                if (!file.delete()) {

// occurs maximum number of times, the error value returned depends on how
// golang's map orders keys. This doesn't affect correctness as long as quorum
// value is greater than or equal to simple majority, since none of the equally
// maximal values would occur quorum or more number of times.
func reduceErrs(errs []error, ignoredErrs []error) (maxCount int, maxErr error) {

# kernel registration - REGISTER_OP, REGISTER_KERNEL_BUILDER, etc.
#
# This setting is currently experimental. The 'v2' implementation does _not_
# correspond to a particular, finalized design; rather, it relates to
# developing one.
#
# The current aim of the 'v2' implementation is to allow 'unused' ops and
# kernels to be discarded by the linker (to the benefit of binary size).
bool_flag(

	if err != nil {
		t.Fatalf("Failed to marshal versioning config: %v", err)
	}

	bucket := "bucket"
	now := time.Now()
	meta := BucketMetadata{
		Name:                      bucket,
		Created:                   now,
		LifecycleConfigXML:        []byte(lcXML),
		VersioningConfigXML:       vcfgXML,
		VersioningConfigUpdatedAt: now,
		LifecycleConfigUpdatedAt:  now,
		lifecycleConfig:           lc,