{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[13] *}

Let's focus on the parameters declared:

* Even though this function is a dependency ("dependable") itself, it also declares another dependency (it "depends" on something else).
    * It depends on the `query_extractor`, and assigns the value returned by it to the parameter `q`.
* It also declares an optional `last_query` cookie, as a `str`.

    //                                     Parameter Logging
    //                                     -----------------
    // logging filter cannot show the parameters when multi-part so logging here
    protected void showFieldLoggingTitle() {
        if (logger.isDebugEnabled()) {
            logger.debug("[Multipart Request Parameter]");
        }
    }

## Using `BackgroundTasks` { #using-backgroundtasks }

First, import `BackgroundTasks` and define a parameter in your *path operation function* with a type declaration of `BackgroundTasks`:

{* ../../docs_src/background_tasks/tutorial001_py310.py hl[1,13] *}

**FastAPI** will create the object of type `BackgroundTasks` for you and pass it as that parameter.

## Create a task function { #create-a-task-function }

import java.lang.annotation.Target;

/**
 * Marks a method as an event subscriber.
 *
 * <p>The type of event will be indicated by the method's first (and only) parameter, which cannot
 * be primitive. If this annotation is applied to methods with zero parameters, or more than one
 * parameter, the object containing the method will not be able to register for event delivery from
 * the {@link EventBus}.
 *

Aber dieser Leitfaden zeigt Ihnen mehr oder weniger, wie die beiden normalerweise verwendet werden.

///

### Pydantics `exclude_unset`-Parameter verwenden { #using-pydantics-exclude-unset-parameter }

Wenn Sie Teil-Aktualisierungen entgegennehmen, ist der `exclude_unset`-Parameter in der `.model_dump()`-Methode von Pydantic-Modellen sehr nützlich.

Wie in `item.model_dump(exclude_unset=True)`.

        // Setup - verify parameter order is correct
        final VaMessenger<FessMessages> messageCode = messages -> messages.addErrorsInvalidQueryUnknown(UserMessages.GLOBAL_PROPERTY_KEY);
        final String message = "Parameter order test";
        final Exception cause = new RuntimeException("Test cause");

        // Execute with three parameters

```

///

## Importer `File` et `Form` { #import-file-and-form }

{* ../../docs_src/request_forms_and_files/tutorial001_an_py310.py hl[3] *}

## Définir des paramètres `File` et `Form` { #define-file-and-form-parameters }

Créez des paramètres de fichier et de formulaire de la même manière que pour `Body` ou `Query` :

{* ../../docs_src/request_forms_and_files/tutorial001_an_py310.py hl[10:12] *}

   *
   * @param iterator the iterator whose minimum element is to be determined
   * @throws NoSuchElementException if {@code iterator} is empty
   * @throws ClassCastException if the parameters are not <i>mutually comparable</i> under this
   *     ordering.
   * @since 11.0
   */
  @ParametricNullness
  public <E extends T> E min(Iterator<E> iterator) {

So wie auch `Body`, `Query`, usw., verwenden Sie `Depends` mit den Parametern Ihrer *Pfadoperation-Funktion*:

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[13,18] *}

Obwohl Sie `Depends` in den Parametern Ihrer Funktion genauso verwenden wie `Body`, `Query`, usw., funktioniert `Depends` etwas anders.

Sie übergeben `Depends` nur einen einzigen Parameter.

Dieser Parameter muss so etwas wie eine Funktion sein.

    }

    /**
     * Builds parameter maps for search initialization, creating both query strings
     * and form inputs for the given parameters.
     *
     * @param paramMap the parameter map to process
     * @param queryKey the key for storing query string parameters
     * @param formKey the key for storing form input parameters
     */