Method result_iterator

Lib/concurrent/futures/_base.py:653–671

()

        # Yield must be hidden in closure so that the futures are submitted
        # before the first iterator value is required.
        def result_iterator():
            try:
                # reverse to keep finishing order
                fs.reverse()
                while fs:
                    if (
                        buffersize
                        and (executor := executor_weakref())
                        and (args := next(zipped_iterables, None))
                    ):
                        fs.appendleft(executor.submit(fn, *args))
                    # Careful not to keep a reference to the popped future
                    if timeout is None:
                        yield _result_or_cancel(fs.pop())
                    else:
                        yield _result_or_cancel(fs.pop(), end_time - time.monotonic())
            finally:
                for future in fs:
                    future.cancel()
        return result_iterator()

    def shutdown(self, wait=True, *, cancel_futures=False):