Elle peut être une fonction asynchrone (`async def`) ou une fonction normale (`def`), **FastAPI** saura la gérer correctement.

Dans cet exemple, la fonction de tâche écrira dans un fichier (afin de simuler un envoi d'email).

L'opération d'écriture n'utilisant ni `async` ni `await`, on définit la fonction avec un `def` normal.

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}

## Ajouter une tâche d'arrière-plan

 * Doing it correctly would require running a Gradle build with the full
 * distribution and extracting the generated api jar from its Gradle user home,
 * slowing down building documentation.
 *
 * All this would be so much simpler if the Kotlin extensions to the Gradle API
 * were generated at build time instead.
 *
 * This is a first step to get the doc to be complete and will be revisited.
 */
@CacheableTask

   *
   * <p>If all input data to this {@code TopKSelector} is in a single {@code Iterable}, prefer
   * {@link Ordering#leastOf(Iterable, int)}, which provides a simpler API for that use case.
   */
  public void offerAll(Iterable<? extends T> elements) {
    offerAll(elements.iterator());
  }

  /**

Cela signifie que **FastAPI** a été spécifiquement testé avec les éditeurs utilisés par 80% des développeurs Python. Et comme la plupart des autres éditeurs ont tendance à fonctionner de façon similaire, tous ses avantages devraient fonctionner pour pratiquement tous les éditeurs.

 *
 * For example, the first line has a parameter name/value pair and the second line has a single
 * token68:
 *
 * ```
 * WWW-Authenticate: Digest foo=bar
 * WWW-Authenticate: Digest foo=
 * ```
 *
 * Similarly, the first line has one challenge and the second line has two challenges:
 *
 * ```
 * WWW-Authenticate: Digest ,foo=bar
 * WWW-Authenticate: Digest ,foo
 * ```
 */

 * the context of {@code class MyStringList implements List<String>}). In such case, prefer to use
 * {@link TypeToken#resolveType} since it's simpler and more type safe. This class should only be
 * used when the type mapping isn't implied by the static type hierarchy, but provided through other
 * means such as an annotation or external configuration file.
 *

     */
    Set<Throwable> seenExceptionsLocal = seenExceptions;
    if (seenExceptionsLocal == null) {
      // TODO(cpovirk): Should we use a simpler (presumably cheaper) data structure?
      /*
       * Using weak references here could let us release exceptions earlier, but:
       *

	// form http://localhost:8181/v1/data/httpapi/authz
	type opaResultAllow struct {
		Result struct {
			Allow bool `json:"allow"`
		} `json:"result"`
	}

	// Handle simpler OPA responses when OPA URL is of
	// form http://localhost:8181/v1/data/httpapi/authz/allow
	type opaResult struct {
		Result bool `json:"result"`
	}

	respBody := bytes.NewReader(opaRespBytes)

It means that **FastAPI** was specifically tested with the editors used by 80% of the Python developers. And as most of the other editors tend to work similarly, all its benefits should work for virtually all editors.

That way I could find the best ways to reduce code duplication as much as possible, to have completion everywhere, type and error checks, etc.

This new `examples` field in JSON Schema is **just a `list`** of examples, not a dict with extra metadata as in the other places in OpenAPI (described above).

/// info

Even after OpenAPI 3.1.0 was released with this new simpler integration with JSON Schema, for a while, Swagger UI, the tool that provides the automatic docs, didn't support OpenAPI 3.1.0 (it does since version 5.0.0 🎉).