{* ../../docs_src/dependencies/tutorial010_py310.py hl[1:9,13] *}

/// tip | İpucu

Bir context manager oluşturmanın başka bir yolu da şunlardır:

* [`@contextlib.contextmanager`](https://docs.python.org/3/library/contextlib.html#contextlib.contextmanager) veya
* [`@contextlib.asynccontextmanager`](https://docs.python.org/3/library/contextlib.html#contextlib.asynccontextmanager)

///

/// note | Технічні деталі

Будь-яка функція, яку можна використовувати з:

* [`@contextlib.contextmanager`](https://docs.python.org/3/library/contextlib.html#contextlib.contextmanager) або
* [`@contextlib.asynccontextmanager`](https://docs.python.org/3/library/contextlib.html#contextlib.asynccontextmanager)

буде придатною як залежність у **FastAPI**.

Насправді FastAPI використовує ці два декоратори внутрішньо.

        FessConfig fessConfig = ComponentUtil.getFessConfig();
        QueryContext context1 = new QueryContext("test", true);
        QueryContext context2 = new QueryContext("test", true);

        // Using template method
        QueryBuilder result1 = queryCommand.convertWithFieldCheck(fessConfig, context1, "title", "test", 1.0f,
                (field, boost) -> QueryBuilders.matchQuery(field, "test").boost(boost),

/// tip | 提示

确保在每个依赖里只使用一次 `yield`。

///

/// note | 技术细节

任何可以与以下装饰器一起使用的函数：

* [`@contextlib.contextmanager`](https://docs.python.org/3/library/contextlib.html#contextlib.contextmanager) 或
* [`@contextlib.asynccontextmanager`](https://docs.python.org/3/library/contextlib.html#contextlib.asynccontextmanager)

都可以作为 **FastAPI** 的依赖项。

实际上，FastAPI 在内部就是用的这两个装饰器。

///

```jinja hl_lines="7"
{!../../docs_src/templates/templates/item.html!}
```

### Valores de Contexto de la Plantilla { #template-context-values }

En el HTML que contiene:

{% raw %}

```jinja
Item ID: {{ id }}
```

{% endraw %}

...mostrará el `id` tomado del `dict` de "contexto" que pasaste:

```Python
{"id": id}
```

Por ejemplo, con un ID de `42`, esto se renderizaría como:

                                                     bool use_tfrt);

// Returns the context_id from the EagerContext which is used by the
// EagerService to maintain consistency between client and worker. The
// context_id is initialized with a dummy value and is later set when the worker
// is initialized (either locally or remotely). The context_id can change during
// the process lifetime although this should cause the worker to be

                testEncryptionKey, testDecryptionKey);

        // When/Then - Multiple closes should be safe
        assertDoesNotThrow(() -> {
            context.close();
            context.close();
            context.close();
        });

        assertTrue(context.isClosed());
    }

/// tip | 豆知識

`yield`は必ず依存関係ごとに1回だけ使用するようにしてください。

///

/// note | 技術詳細

以下と一緒に使用できる関数なら何でも有効です:

* [`@contextlib.contextmanager`](https://docs.python.org/3/library/contextlib.html#contextlib.contextmanager) または
* [`@contextlib.asynccontextmanager`](https://docs.python.org/3/library/contextlib.html#contextlib.asynccontextmanager)

これらは **FastAPI** の依存関係として使用するのに有効です。

実際、FastAPIは内部的にこれら２つのデコレータを使用しています。

///

from contextlib import asynccontextmanager

from fastapi import FastAPI


def fake_answer_to_everything_ml_model(x: float):
    return x * 42


ml_models = {}


@asynccontextmanager
async def lifespan(app: FastAPI):
    # Load the ML model
    ml_models["answer_to_everything"] = fake_answer_to_everything_ml_model
    yield
    # Clean up the ML models and release the resources
    ml_models.clear()

from collections.abc import AsyncGenerator
from contextlib import AbstractContextManager
from contextlib import asynccontextmanager as asynccontextmanager
from typing import TypeVar

import anyio.to_thread
from anyio import CapacityLimiter
from starlette.concurrency import iterate_in_threadpool as iterate_in_threadpool  # noqa
from starlette.concurrency import run_in_threadpool as run_in_threadpool  # noqa
from starlette.concurrency import (  # noqa