for item in items:
        yield item


@app.get("/items/stream-no-async", response_class=EventSourceResponse)
def sse_items_no_async() -> Iterable[Item]:
    for item in items:
        yield item


@app.get("/items/stream-no-annotation", response_class=EventSourceResponse)
async def sse_items_no_annotation():
    for item in items:
        yield item

	elapsed := time.Since(begin)
	sql, rows := fc()
	fields := []slog.Attr{
		slog.String("duration", fmt.Sprintf("%.3fms", float64(elapsed.Nanoseconds())/1e6)),
		slog.String("sql", sql),
	}

	if rows != -1 {
		fields = append(fields, slog.Int64("rows", rows))
	}

	switch {
	case err != nil && (!l.IgnoreRecordNotFoundError || !errors.Is(err, ErrRecordNotFound)):
		fields = append(fields, slog.String("error", err.Error()))

For example, in one of the ways the OAuth2 specification can be used (called "password flow") it is required to send a `username` and `password` as form fields.

The <dfn title="specification">spec</dfn> requires the fields to be exactly named `username` and `password`, and to be sent as form fields, not JSON.

///

### `yield from` { #yield-from }

Bir şeyin (ör. dosya benzeri bir nesne) üzerinde iterate ederken, her öğe için `yield` yapıyorsanız, `for` döngüsünü yazmak yerine `yield from` ile her öğeyi doğrudan yield edebilirsiniz.

Bu FastAPI'ye özgü değildir, tamamen Python'dur, ama bilinmesi güzel bir püf noktasıdır. 😎

@app.get("/items/stream-invalid")
async def stream_items_invalid() -> AsyncIterable[Item]:
    yield {"name": "valid", "price": 1.0}
    yield {"name": "invalid", "price": "not-a-number"}


@app.get("/items/stream-invalid-sync")
def stream_items_invalid_sync() -> Iterable[Item]:
    yield {"name": "valid", "price": 1.0}
    yield {"name": "invalid", "price": "not-a-number"}


client = TestClient(app)

            if self.open:
                yield item
            else:
                raise ValueError("Session closed")


@contextmanager
def acquire_session() -> Generator[Session, None, None]:
    session = Session()
    try:
        yield session
    finally:
        session.open = False


def dep_session() -> Any:
    with acquire_session() as s:
        yield s


def broken_dep_session() -> Any:

///

### `yield from` { #yield-from }

Wenn Sie über etwas iterieren, z. B. ein dateiähnliches Objekt, und dann für jedes Element `yield` verwenden, könnten Sie auch `yield from` verwenden, um jedes Element direkt weiterzugeben und die `for`-Schleife zu sparen.

///

### `yield from` { #yield-from }

Quando você está iterando sobre algo, como um objeto semelhante a arquivo, e faz `yield` para cada item, você também pode usar `yield from` para produzir cada item diretamente e pular o loop `for`.

def gen_dependency(value: str) -> Generator[str, None, None]:
    yield value


async def async_gen_dependency(value: str) -> AsyncGenerator[str, None]:
    yield value


class CallableDependency:
    def __call__(self, value: str) -> str:
        return value


class CallableGenDependency:
    def __call__(self, value: str) -> Generator[str, None, None]:
        yield value


class AsyncCallableDependency:

The files and form fields will be uploaded as form data and you will receive the files and form fields.

And you can declare some of the files as `bytes` and some as `UploadFile`.

/// warning