'input_tensor': np.random.uniform(low=-1.0, high=1.0, size=(1, 4))
        }

    repr_ds = data_gen()
    self.assertIsNone(repr_dataset.get_num_samples(repr_ds))

    # Make sure that the __next__() is never called during the
    # get_num_samples call.
    self.assertLen(list(repr_ds), num_samples)

  def test_get_num_samples_returns_none_when_len_raises_error(self):
    class LenRaisingError:

async def contextmanager_in_threadpool(
    cm: ContextManager[_T],
) -> AsyncGenerator[_T, None]:
    # blocking __exit__ from running waiting on a free thread
    # can create race conditions/deadlocks if the context manager itself
    # has its own internal pool (e.g. a database connection pool)
    # to avoid this we let __exit__ run without a capacity limit
    # since we're creating a new limiter for each call, any non-zero limit

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:

		{unescaped: "for", escaped: "__for__"},
		{unescaped: "function", escaped: "__function__"},
		{unescaped: "if", escaped: "__if__"},
		{unescaped: "import", escaped: "__import__"},
		{unescaped: "let", escaped: "__let__"},
		{unescaped: "loop", escaped: "__loop__"},
		{unescaped: "package", escaped: "__package__"},
		{unescaped: "namespace", escaped: "__namespace__"},
		{unescaped: "return", escaped: "__return__"},

     * Wait for the interrupting thread to set DONE. (See interruptTask().) We want to wait so that
     * the interrupting thread doesn't interrupt the _next_ thing to run on this thread.
     *
     * Note: We don't reset the interrupted bit, just wait for it to be set. If this is a thread
     * pool thread, the thread pool will reset it for us. Otherwise, the interrupted bit may have

    🚥 👆 ▶️ ⏮️ **FastAPI** 👆 💪 💚 🚶 ⚫️ 🔜.

🐍, 👆 💪 ✍ 🔑 👨‍💼 <a href="https://docs.python.org/3/reference/datamodel.html#context-managers" class="external-link" target="_blank">🏗 🎓 ⏮️ 2️⃣ 👩‍🔬: `__enter__()` &amp; `__exit__()`</a>.

👆 💪 ⚙️ 👫 🔘 **FastAPI** 🔗 ⏮️ `yield` ⚙️
`with` ⚖️ `async with` 📄 🔘 🔗 🔢:

```Python hl_lines="1-9  13"
{!../../../docs_src/dependencies/tutorial010.py!}
```

!!! tip

     * Wait for the interrupting thread to set DONE. (See interruptTask().) We want to wait so that
     * the interrupting thread doesn't interrupt the _next_ thing to run on this thread.
     *
     * Note: We don't reset the interrupted bit, just wait for it to be set. If this is a thread
     * pool thread, the thread pool will reset it for us. Otherwise, the interrupted bit may have

In Python können Sie Kontextmanager erstellen, indem Sie <a href="https://docs.python.org/3/reference/datamodel.html#context-managers" class="external-link" target="_blank">eine Klasse mit zwei Methoden erzeugen: `__enter__()` und `__exit__()`</a>.

Sie können solche auch innerhalb von **FastAPI**-Abhängigkeiten mit `yield` verwenden, indem Sie `with`- oder `async with`-Anweisungen innerhalb der Abhängigkeits-Funktion verwenden:

```Python hl_lines="1-9  13"

В Python для создания менеджеров контекста можно <a href="https://docs.python.org/3/reference/datamodel.html#context-managers" class="external-link" target="_blank">создать класс с двумя методами: `__enter__()` и `__exit__()`</a>.

Вы также можете использовать их внутри зависимостей **FastAPI** с `yield`, используя операторы
`with` или `async with` внутри функции зависимости:

```Python hl_lines="1-9  13"

In Python, you can create Context Managers by <a href="https://docs.python.org/3/reference/datamodel.html#context-managers" class="external-link" target="_blank">creating a class with two methods: `__enter__()` and `__exit__()`</a>.

You can also use them inside of **FastAPI** dependencies with `yield` by using
`with` or `async with` statements inside of the dependency function:

```Python hl_lines="1-9  13"