///

Les réponses générées au format OpenAPI pour cette *opération de chemin* seront :

```JSON hl_lines="3-12"
{
    "responses": {
        "404": {
            "description": "Additional Response",
            "content": {
                "application/json": {

    return {"name": fake_items_db[item_id]["name"], "item_id": item_id}


@router.put(
    "/{item_id}",
    tags=["custom"],
    responses={403: {"description": "Operation forbidden"}},
)
async def update_item(item_id: str):
    if item_id != "plumbus":
        raise HTTPException(
            status_code=403, detail="You can only update the item: plumbus"
        )

    offerAll(elements.iterator());
  }

  /**
   * Adds each member of {@code elements} as a candidate for the top {@code k} elements. This
   * operation takes amortized linear time in the length of {@code elements}. The iterator is
   * consumed after this operation completes.
   *
   * <p>If all input data to this {@code TopKSelector} is in a single {@code Iterator}, prefer

func (a adminAPIHandlers) SRPeerBucketOps(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()

	objectAPI, _ := validateAdminReq(ctx, w, r, policy.SiteReplicationOperationAction)
	if objectAPI == nil {
		return
	}

	vars := mux.Vars(r)
	bucket := vars["bucket"]
	operation := madmin.BktOp(vars["operation"])

	var err error
	switch operation {

             "config": "/apis/networking.istio.io/v1/namespaces/default/virtual-service/http-0-istio-autogenerated-k8s-gateway"
            }
           }
          },
          "decorator": {
           "operation": "httpbin.default.svc.cluster.local:8000/*"
          },
          "name": "default.http.0"
         }
        ],
        "include_request_attempt_count": true
       }
      ],

Esse parâmetro não cria um endpoint / *path operation*, mas declara que a URL `/token` vai ser aquela que o client deve usar para obter o token. Essa informação é usada no OpenAPI, e depois na API Interativa de documentação de sistemas.

Em breve também criaremos o atual path operation.

/// info | "informação"



///

# レスポンスを直接返す

**FastAPI** の *path operation* では、通常は任意のデータを返すことができます: 例えば、 `dict`、`list`、Pydanticモデル、データベースモデルなどです。

デフォルトでは、**FastAPI** は [JSON互換エンコーダ](../tutorial/encoder.md){.internal-link target=_blank} で説明されている `jsonable_encoder` により、返す値を自動的にJSONに変換します。

このとき背後では、JSON互換なデータ (例えば`dict`) を、クライアントへ送信されるレスポンスとして利用される `JSONResponse` の中に含めます。

しかし、*path operation* から `JSONResponse` を直接返すこともできます。

これは例えば、カスタムヘッダーやcookieを返すときに便利です。

## `Response` を返す

# Background Tasks - `BackgroundTasks`

You can declare a parameter in a *path operation function* or dependency function with the type `BackgroundTasks`, and then you can use it to schedule the execution of background tasks after the response is sent.

You can import it directly from `fastapi`:

```python
from fastapi import BackgroundTasks
```

  // lifetime through ref counting. Thus clients MUST call Release() in order to
  // destroy an instance of this class.
  virtual void Release() = 0;

  // Creates an operation builder and ties it to this context.
  // The returned object can be used for setting operation's attributes,
  // adding inputs and finally executing (immediately or lazily as in tracing)
  // it in this context.

//   {"/job:localhost/replica:0/task:0/device:GPU:0",
//    "/job:localhost/replica:0/task:0/device:GPU:1"}
// Then executing an operation on CUSTOM:0 will execute it on GPU:0 and GPU:1.
//
// Implicit copies onto `device_name` are allowed, replicating the value once
// per device in `underlying_devices`. Implicit copies off of the device throw
// an error.
//
// All component tensors must have the same dtype. Currently they must also have