Function maybe_deferred_to_future

scrapy/utils/defer.py:499–524

Return *d* as an object that can be awaited from a :ref:`Scrapy callable defined as a coroutine <coroutine-support>`. What you can await in Scrapy callables defined as coroutines depends on the value of :setting:`TWISTED_REACTOR`: - When :ref:`using the asyncio reactor <install-a

(d: Deferred[_T])

def maybe_deferred_to_future(d: Deferred[_T]) -> Deferred[_T] | Future[_T]:
    class="st">"""Return *d* as an object that can be awaited from a :ref:`Scrapy callable
    defined as a coroutine <coroutine-support>`.

    What you can await in Scrapy callables defined as coroutines depends on the
    value of :setting:`TWISTED_REACTOR`:

    -   When :ref:`using the asyncio reactor <install-asyncio>`, you can only
        await on :class:`asyncio.Future` objects.

    -   When not using the asyncio reactor, you can only await on
        :class:`~twisted.internet.defer.Deferred` objects.

    If you want to write code that uses ``Deferred`` objects but works with any
    reactor, use this function on all ``Deferred`` objects::

        class MySpider(Spider):
            ...
            async def parse(self, response):
                additional_request = scrapy.Request(&class="cm">#x27;https://example.org/price')
                deferred = self.crawler.engine.download(additional_request)
                additional_response = await maybe_deferred_to_future(deferred)
    class="st">"""
    if not is_asyncio_available():
        return d
    return deferred_to_future(d)


def _schedule_coro(coro: Coroutine[Any, Any, Any]) -> None: