## Primera dependencia "dependable" { #first-dependency-dependable }

Podrías crear una primera dependencia ("dependable") así:

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[8:9] *}

Declara un parámetro de query opcional `q` como un `str`, y luego simplemente lo devuelve.

Esto es bastante simple (no muy útil), pero nos ayudará a centrarnos en cómo funcionan las sub-dependencias.

		code:       "InvalidRequestParameter",
		message:    "The value of a parameter in SelectRequest element is invalid. Check the service API documentation and try again.",
		statusCode: 400,
		cause:      err,
	}
}

func errInvalidScanRangeParameter(err error) *s3Error {
	return &s3Error{
		code:       "InvalidRequestParameter",

The `lifespan` parameter of the `FastAPI` app takes an **async context manager**, so we can pass our new `lifespan` async context manager to it.

{* ../../docs_src/events/tutorial003_py310.py hl[22] *}

## Alternative Events (deprecated) { #alternative-events-deprecated }

/// warning

Vous en apprendrez davantage sur l'utilisation des variables d'environnement pour gérer les **paramètres d'application** dans le [Guide utilisateur avancé - Paramètres et variables d'environnement](./advanced/settings.md).

## Variable d'environnement `PATH` { #path-environment-variable }

## Eventos alternativos (descontinuados) { #alternative-events-deprecated }

/// warning | Atenção

A forma recomendada de lidar com a *inicialização* e o *encerramento* é usando o parâmetro `lifespan` da aplicação `FastAPI`, como descrito acima. Se você fornecer um parâmetro `lifespan`, os manipuladores de eventos `startup` e `shutdown` não serão mais chamados. É tudo `lifespan` ou tudo por eventos, não ambos.

Você provavelmente pode pular esta parte.

///

                    clientMaxWindowBits = value?.toIntOrNull()
                    if (clientMaxWindowBits == null) unexpectedValues = true // Not an int!
                  }

                  name.equals("client_no_context_takeover", ignoreCase = true) -> {
                    if (clientNoContextTakeover) unexpectedValues = true // Repeated parameter!

    }
  }

  /*
   * Preconditions.checkNotNull is *intended* for performing eager null checks on parameters that a
   * nullness checker can already "prove" are non-null. That means that the first parameter to
   * checkNotNull *should* be annotated to require it to be non-null.
   *
   * However, for a variety of reasons, Google developers have written a ton of code over the past

///

### Bir *Path Parameter* Tanımlayalım { #declare-a-path-parameter }

Ardından oluşturduğunuz enum sınıfını (`ModelName`) kullanarak tip belirteciyle bir *path parameter* oluşturun:

{* ../../docs_src/path_params/tutorial005_py310.py hl[16] *}

### Dokümana Göz Atalım { #check-the-docs }

   *       superclass, no equality check is done on the deserialized instance because it's not clear
   *       whether the author intended for the class to be a value type.
   *   <li>If a constructor or factory method takes a parameter whose type is interface, a dynamic
   *       proxy will be passed to the method. It's possible that the method body expects an
   *       instance method of the passed-in proxy to be of a certain value yet the proxy isn't aware

     * Checks whether the arguments are suitable for the parameter types.
     *
     * @param paramTypes
     *            array of parameter types
     * @param args
     *            array of arguments
     * @param adjustNumber
     *            if {@literal true}, converts arguments to match number types if necessary
     * @return {@literal true} if the arguments are suitable for the parameter types
     */