This is vendored from Starlette to avoid importing private symbols.
    """

    def __init__(self, cm: AbstractContextManager[_T]) -> None:
        self._cm = cm

    async def __aenter__(self) -> _T:
        return self._cm.__enter__()

    async def __aexit__(
        self,
        exc_type: type[BaseException] | None,
        exc_value: BaseException | None,
        traceback: types.TracebackType | None,

class MySuperContextManager:
    def __init__(self):
        self.db = DBSession()

    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:

    # since we're creating a new limiter for each call, any non-zero limit
    # works (1 is arbitrary)
    exit_limiter = CapacityLimiter(1)
    try:
        yield await run_in_threadpool(cm.__enter__)
    except Exception as e:
        ok = bool(
            await anyio.to_thread.run_sync(
                cm.__exit__, type(e), e, e.__traceback__, limiter=exit_limiter
            )
        )
        if not ok:

        self.reset_at: datetime = datetime.fromtimestamp(0, timezone.utc)
        self.last_request_start_time: datetime = datetime.fromtimestamp(0, timezone.utc)
        self.speed_multiplier: float = 1.0

    def __enter__(self) -> "RateLimiter":
        now = datetime.now(tz=timezone.utc)

        # Handle primary rate limits
        primary_limit_wait_time = 0.0
        if self.remaining_points <= self.last_query_cost:

Bu, az çok "ileri seviye" bir fikirdir.

**FastAPI**'ye yeni başlıyorsanız şimdilik bunu atlamak isteyebilirsiniz.

///

Python'da Context Manager'ları, [iki method'a sahip bir class oluşturarak: `__enter__()` ve `__exit__()`](https://docs.python.org/3/reference/datamodel.html#context-managers) yaratabilirsiniz.

Si vous débutez avec **FastAPI**, vous voudrez peut-être l'ignorer pour le moment.

///

En Python, vous pouvez créer des gestionnaires de contexte en [créant une classe avec deux méthodes : `__enter__()` et `__exit__()`](https://docs.python.org/3/reference/datamodel.html#context-managers).

Vous pouvez également les utiliser dans des dépendances **FastAPI** avec `yield` en utilisant

Це, загалом, «просунута» ідея.

Якщо ви тільки починаєте з **FastAPI**, можливо, варто наразі пропустити це.

///

У Python ви можете створювати Менеджери контексту, [створивши клас із двома методами: `__enter__()` і `__exit__()`](https://docs.python.org/3/reference/datamodel.html#context-managers).

Ви також можете використовувати їх усередині залежностей **FastAPI** з `yield`, використовуючи

Esto es, más o menos, una idea "avanzada".

Si apenas estás comenzando con **FastAPI**, podrías querer omitirlo por ahora.

///

En Python, puedes crear Context Managers [creando una clase con dos métodos: `__enter__()` y `__exit__()`](https://docs.python.org/3/reference/datamodel.html#context-managers).

También puedes usarlos dentro de las dependencias de **FastAPI** con `yield` usando
`with` o `async with` en la función de dependencia:

### 在含 `yield` 的相依中使用情境管理器 { #using-context-managers-in-dependencies-with-yield }

/// warning

這大致算是一個「進階」概念。

如果你剛開始學習 **FastAPI**，此處可以先跳過。

///

在 Python 中，你可以透過[建立一個擁有 `__enter__()` 與 `__exit__()` 兩個方法的類別](https://docs.python.org/3/reference/datamodel.html#context-managers)來建立情境管理器。

你也可以在 **FastAPI** 的含 `yield` 相依中，於相依函式內使用 `with` 或 `async with` 陳述式來使用它們：

This is, more or less, an "advanced" idea.

If you are just starting with **FastAPI** you might want to skip it for now.

///

In Python, you can create Context Managers by [creating a class with two methods: `__enter__()` and `__exit__()`](https://docs.python.org/3/reference/datamodel.html#context-managers).

You can also use them inside of **FastAPI** dependencies with `yield` by using