"""Represents a single Server-Sent Event.

    When `yield`ed from a *path operation function* that uses
    `response_class=EventSourceResponse`, each `ServerSentEvent` is encoded
    into the [SSE wire format](https://html.spec.whatwg.org/multipage/server-sent-events.html#parsing-an-event-stream)
    (`text/event-stream`).

    If you yield a plain object (dict, Pydantic model, etc.) instead, it is

                    yield webConfigService.getWebConfig(id).get();
                }
                case FILE -> {
                    final FileConfigService fileConfigService = ComponentUtil.getComponent(FileConfigService.class);
                    yield fileConfigService.getFileConfig(id).get();
                }
                case DATA -> {

    """Async generator with no internal await - would hang without checkpoint."""
    i = 0
    while True:
        yield f"item {i}\n"
        i += 1


@app.get("/stream-jsonl")
async def stream_jsonl() -> AsyncIterable[int]:
    """JSONL async generator with no internal await."""
    i = 0
    while True:
        yield i
        i += 1


async def _run_asgi_and_cancel(app: FastAPI, path: str, timeout: float) -> bool:

    corruptor()

    return client.newCall(request).execute()
  }

  /**
   * @param delta the offset from the current date to use. Negative values yield dates in the past;
   *     positive values yield dates in the future.
   */
  private fun formatDate(
    delta: Long,
    timeUnit: TimeUnit,
  ): String? = formatDate(Date(System.currentTimeMillis() + timeUnit.toMillis(delta)))

from typing import Annotated

from fastapi import Depends, FastAPI

app = FastAPI()


def get_username():
    try:
        yield "Rick"
    finally:
        print("Cleanup up before response is sent")


@app.get("/users/me")
def get_user_me(username: Annotated[str, Depends(get_username, scope="function")]):

///

## FastAPI で SSE をストリーミング { #stream-sse-with-fastapi }

FastAPI で SSE をストリーミングするには、*path operation 関数*で `yield` を使い、`response_class=EventSourceResponse` を設定します。

`EventSourceResponse` は `fastapi.sse` からインポートします:

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

yield された各アイテムは JSON にエンコードされ、SSE イベントの `data:` フィールドで送信されます。

        Path("docs/en/docs/advanced"),
        Path("docs/en/docs/about"),
        Path("docs/en/docs/how-to"),
    ]
    first_parent = Path("docs/en/docs")
    yield from first_parent.glob("*.md")
    for dir_path in first_dirs:
        yield from dir_path.rglob("*.md")
    first_dirs_str = tuple(str(d) for d in first_dirs)
    for path in Path("docs/en/docs").rglob("*.md"):
        if str(path).startswith(first_dirs_str):

비디오나 오디오처럼 바이너리 데이터를 스트리밍하려면 고급 가이드를 확인하세요: [스트림 데이터](../advanced/stream-data.md).

///

## FastAPI로 JSON Lines 스트리밍 { #stream-json-lines-with-fastapi }

FastAPI에서 JSON Lines를 스트리밍하려면, *경로 처리 함수*에서 `return`을 사용하는 대신 `yield`로 각 항목을 차례로 생성하면 됩니다.

{* ../../docs_src/stream_json_lines/tutorial001_py310.py ln[1:24] hl[24] *}

보내려는 각 JSON 항목의 타입이 `Item`(Pydantic 모델)이고 함수가 async라면, 반환 타입을 `AsyncIterable[Item]`로 선언할 수 있습니다:

 *       always returns zero could be called a hash function. It is not.)
 * </ul>
 *
 * <p>Summarizing the last two points: "equal yield equal <i>always</i>; unequal yield unequal
 * <i>often</i>." This is the most important characteristic of all hash functions.
 *
 * <h3>Desirable properties</h3>
 *

    def __enter__(self):
        return self.db

    def __exit__(self, exc_type, exc_value, traceback):
        self.db.close()


async def get_db():
    with MySuperContextManager() as db: