{* ../../docs_src/server_sent_events/tutorial001_py310.py ln[1:25] hl[4,22] *}

Each yielded item is encoded as JSON and sent in the `data:` field of an SSE event.

If you declare the return type as `AsyncIterable[Item]`, FastAPI will use it to **validate**, **document**, and **serialize** the data using Pydantic.

{* ../../docs_src/server_sent_events/tutorial001_py310.py ln[1:25] hl[10:12,23] *}

/// tip

///

## Dataclasses in `response_model` { #dataclasses-in-response-model }

You can also use `dataclasses` in the `response_model` parameter:

{* ../../docs_src/dataclasses_/tutorial002_py310.py hl[1,6:12,18] *}

The dataclass will be automatically converted to a Pydantic dataclass.

This way, its schema will show up in the API docs user interface:

<img src="/img/tutorial/dataclasses/image01.png">

Let's see the previous example again:

{* ../../docs_src/response_status_code/tutorial001_py310.py hl[6] *}

`201` is the status code for "Created".

But you don't have to memorize what each of these codes mean.

You can use the convenience variables from `fastapi.status`.

{* ../../docs_src/response_status_code/tutorial002_py310.py hl[1,6] *}

{* ../../docs_src/path_operation_advanced_configuration/tutorial001_py310.py hl[6] *}

### *경로 처리 함수* 이름을 operationId로 사용하기 { #using-the-path-operation-function-name-as-the-operationid }

API의 함수 이름을 `operationId`로 사용하고 싶다면, 모든 API를 순회하면서 `APIRoute.name`을 사용해 각 *경로 처리*의 `operation_id`를 덮어쓸 수 있습니다.

모든 *경로 처리*를 추가한 뒤에 수행해야 합니다.

{* ../../docs_src/path_operation_advanced_configuration/tutorial002_py310.py hl[2, 12:21, 24] *}

/// tip | 팁

You should do it after adding all your *path operations*.

{* ../../docs_src/path_operation_advanced_configuration/tutorial002_py310.py hl[2, 12:21, 24] *}

/// tip

If you manually call `app.openapi()`, you should update the `operationId`s before that.

///

/// warning

SET_OF_STR_SCHEMA = {"type": "array", "items": {"type": "string"}, "uniqueItems": True}


@pytest.fixture(
    name="mod_name",
    params=[
        pytest.param("tutorial001_py310", marks=needs_py310),
        pytest.param("tutorial002_py310", marks=needs_py310),
        pytest.param("tutorial003_py310", marks=needs_py310),
    ],
)
def get_mod_name(request: pytest.FixtureRequest):
    return request.param


@pytest.fixture(name="client")

{* ../../docs_src/server_sent_events/tutorial002_py310.py hl[4,26] *}

`data` 필드는 항상 JSON으로 인코딩됩니다. Pydantic 모델을 포함해 JSON으로 직렬화할 수 있는 값을 모두 전달할 수 있습니다.

## 원시 데이터 { #raw-data }

JSON 인코딩 없이 데이터를 보내야 한다면, `data` 대신 `raw_data`를 사용하세요.

미리 포맷된 텍스트, 로그 라인, 또는 `[DONE]`과 같은 특수한 <dfn title="특수한 조건이나 상태를 나타내는 데 사용되는 값">"센티널"</dfn> 값을 보낼 때 유용합니다.

{* ../../docs_src/server_sent_events/tutorial003_py310.py hl[17] *}

/// note | 참고

{* ../../docs_src/server_sent_events/tutorial002_py310.py hl[4,26] *}

`data` 欄位一律會以 JSON 編碼。你可以傳入任何可序列化為 JSON 的值，包括 Pydantic 模型。

## 原始資料 { #raw-data }

如果你需要在**不**進行 JSON 編碼的情況下傳送資料，請使用 `raw_data` 取代 `data`。

這對於傳送已格式化的文字、日誌行或特殊的 <dfn title="用於表示特殊條件或狀態的值">"哨兵"</dfn> 值（例如 `[DONE]`）很有用。

{* ../../docs_src/server_sent_events/tutorial003_py310.py hl[17] *}

/// note

Let's say you have a Pydantic model with default values, like this one:

{* ../../docs_src/separate_openapi_schemas/tutorial001_py310.py ln[1:7] hl[7] *}

### Model for Input { #model-for-input }

If you use this model as an input like here:

{* ../../docs_src/separate_openapi_schemas/tutorial001_py310.py ln[1:15] hl[14] *}

...then the `description` field will **not be required**. Because it has a default value of `None`.

We can instead create an input model with the plaintext password and an output model without it:

{* ../../docs_src/response_model/tutorial003_py310.py hl[9,11,16] *}

Here, even though our *path operation function* is returning the same input user that contains the password:

{* ../../docs_src/response_model/tutorial003_py310.py hl[24] *}

...we declared the `response_model` to be our model `UserOut`, that doesn't include the password: