Im obigen Beispiel ist das Eingabemodell ein Pydantic‑v1‑Modell, und das Ausgabemodell (definiert in `response_model=ItemV2`) ist ein Pydantic‑v2‑Modell.

### Pydantic v1 Parameter { #pydantic-v1-parameters }

 * your application's HTTP calls.
 *
 * All start/connect/acquire events will eventually receive a matching end/release event, either
 * successful (non-null parameters), or failed (non-null throwable). The first common parameters of
 * each event pair are used to link the event in case of concurrent or repeated events e.g.
 * `dnsStart(call, domainName)` → `dnsEnd(call, domainName, inetAddressList)`.
 *

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)`.

        },
        "openapi": "3.1.0",
        "paths": {
            "/items/{item_id}": {
                "put": {
                    "operationId": "update_item_items__item_id__put",
                    "parameters": [
                        {
                            "in": "path",
                            "name": "item_id",
                            "required": True,
                            "schema": {

                "/model/{name}": {
                    "get": {
                        "summary": "Get Model A",
                        "operationId": "get_model_a_model__name__get",
                        "parameters": [
                            {
                                "required": True,
                                "schema": {"title": "Name", "type": "string"},
                                "name": "name",

```

///

## Importar `Form` { #import-form }

Importar `Form` desde `fastapi`:

{* ../../docs_src/request_forms/tutorial001_an_py39.py hl[3] *}

## Definir parámetros de `Form` { #define-form-parameters }

Crea parámetros de formulario de la misma manera que lo harías para `Body` o `Query`:

{* ../../docs_src/request_forms/tutorial001_an_py39.py hl[9] *}

                    "operationId": "create_invoice_invoices__post",
                    "parameters": [
                        {
                            "required": False,
                            "schema": {
                                "anyOf": [
                                    {

        SYSTEM_PROPERTIES,
        /**
         * Maven user properties. These are properties that users configure through various means such as
         * maven-user.properties files, maven.config files, command line parameters (-D flags), settings.xml,
         * or environment variables. They are evaluated during the build process and represent the primary
         * way for users to customize Maven's behavior at runtime.
         */

```

///

## Importe `Form` { #import-form }

Importe `Form` de `fastapi`:

{* ../../docs_src/request_forms/tutorial001_an_py39.py hl[3] *}

## Defina parâmetros de `Form` { #define-form-parameters }

Crie parâmetros de formulário da mesma forma que você faria para `Body` ou `Query`:

{* ../../docs_src/request_forms/tutorial001_an_py39.py hl[9] *}

      When doing so, still annotate nullable parameters and the return type as `@Nullable`.
  * Do not use `@Contract` for public APIs.
  * For polynull public APIs, the solution has to be decided on a case-by-case basis.

Do not remove `null` checks on public API boundaries, even if the annotations (or rather lack of them) suggest this.
Not all client code is compiled with NullAway.