**FastAPI** fera ce qu'il faut dans chaque cas, comme avec des dépendances normales.

///

## Créer une dépendance avec `yield` et `try` { #a-dependency-with-yield-and-try }

Si vous utilisez un bloc `try` dans une dépendance avec `yield`, vous recevrez toute exception qui a été levée lors de l'utilisation de la dépendance.

type unwrapper interface {
	Unwrap() http.ResponseWriter
}

// headersAlreadyWritten returns true if the headers have already been written
// to this response writer. It will unwrap the ResponseWriter if possible to try
// and find a trackingResponseWriter.
func headersAlreadyWritten(w http.ResponseWriter) bool {
	for {
		if trw, ok := w.(*trackingResponseWriter); ok {
			return trw.headerWritten

Через эндпоинт веб-сокета вы можете получать и отправлять сообщения.

{* ../../docs_src/websockets_/tutorial001_py310.py hl[48:52] *}

Вы можете получать и отправлять двоичные, текстовые и JSON данные.

## Проверка в действии { #try-it }

Поместите ваш код в файл `main.py`, затем запустите приложение:

<div class="termy">

```console
$ fastapi dev

Sie können `async`- oder reguläre Funktionen verwenden.

**FastAPI** wird bei jeder das Richtige tun, so wie auch bei normalen Abhängigkeiten.

///

## Eine Abhängigkeit mit `yield` und `try` { #a-dependency-with-yield-and-try }

Wenn Sie einen `try`-Block in einer Abhängigkeit mit `yield` verwenden, empfangen Sie alle Exceptions, die bei Verwendung der Abhängigkeit geworfen wurden.

O **FastAPI** saberá o que fazer com cada uma, da mesma forma que as dependências comuns.

///

## Uma dependência com `yield` e `try` { #a-dependency-with-yield-and-try }

Se você utilizar um bloco `try` em uma dependência com `yield`, você irá capturar qualquer exceção que for lançada enquanto a dependência é utilizada.

    }

    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;
  }

  /**
   * Implementation of a transforming random access list. We try to make as many of these methods
   * pass-through to the source list as possible so that the performance characteristics of the
   * source list and transformed list are similar.
   *
   * @see Lists#transform
   */

	if b.r > 0 {
		copy(b.buf, b.buf[b.r:b.w])
		b.w -= b.r
		b.r = 0
	}

	if b.w >= len(b.buf) {
		panic("bufio: tried to fill full buffer")
	}

	// Read new data: try a limited number of times.
	for i := maxConsecutiveEmptyReads; i > 0; i-- {
		n, err := b.rd.Read(b.buf[b.w:])
		if n < 0 {
			panic(errNegativeRead)
		}
		b.w += n
		if err != nil {
			b.err = err

{* ../../docs_src/websockets_/tutorial001_py310.py hl[48:52] *}

Vous pouvez recevoir et envoyer des données binaires, texte et JSON.

## Essayer { #try-it }

Mettez votre code dans un fichier `main.py` puis exécutez votre application :

<div class="termy">

```console
$ fastapi dev

   * collection might be empty, also provide a default comparator as the {@code identity} parameter
   * to {@code reduce}).
   *
   * @param comparators the comparators to try in order
   */
  public static <T extends @Nullable Object> Ordering<T> compound(
      Iterable<? extends Comparator<? super T>> comparators) {
    return new CompoundOrdering<>(comparators);
  }

  /**

	if success {
		return
	}
	hip.clientToken = token
	// if request was not successful, try this server locally if token
	// is not found the call will fail anyways. if token is empty
	// try this server to generate a new token.

	type healResp struct {
		respBytes []byte
		apiErr    APIError
		errBody   string
	}