Function parallel

scrapy/utils/defer.py:159–173

Execute a callable over the objects in the given iterable, in parallel, using no more than ``count`` concurrent calls. Taken from: https://jcalderone.livejournal.com/24285.html

(
    iterable: Iterable[_T],
    count: int,
    callable: Callable[Concatenate[_T, _P], _T2],  # noqa: A002
    *args: _P.args,
    **named: _P.kwargs,
)

def parallel(
    iterable: Iterable[_T],
    count: int,
    callable: Callable[Concatenate[_T, _P], _T2],  # noqa: A002
    *args: _P.args,
    **named: _P.kwargs,
) -> Deferred[list[tuple[bool, Iterator[_T2]]]]:
    """Execute a callable over the objects in the given iterable, in parallel,
    using no more than ``count`` concurrent calls.

    Taken from: https://jcalderone.livejournal.com/24285.html
    """
    coop = Cooperator()
    work: Iterator[_T2] = (callable(elem, *args, **named) for elem in iterable)
    return DeferredList([coop.coiterate(work) for _ in range(count)])


class _AsyncCooperatorAdapter(Iterator[Deferred[Any]], Generic[_T]):