习惯性地从期货的词汇中收集结果

Question

我正在努力写出一些尽可能惯用的东西来收集存储在字典中的期货的结果.

我们假设我有以下代码:

import asyncio

async def sleep(seconds):
    print(f'sleeping for {seconds} seconds')
    await asyncio.sleep(seconds)
    print(f'finished sleeping {seconds} seconds')


async def run():
    tasks = {
        '4': sleep(4),
        '3': sleep(3),
        '2': sleep(2),
        '1': sleep(1),
    }
    print(await gather_from_dict(tasks))


if __name__ == '__main__':
     asyncio.get_event_loop().run_until_complete(run())

我期待的输出是:

sleeping for 2 seconds
sleeping for 1 seconds
sleeping for 4 seconds
sleeping for 3 seconds
finished sleeping 1 seconds
finished sleeping 2 seconds
finished sleeping 3 seconds
finished sleeping 4 seconds
{'4': None, '3': None, '2': None, '1': None}

到目前为止,我发现最干净的解决方案是:

async def gather_from_dict(tasks:Dict[Hashable, Awaitable],
                           loop=None, return_exceptions=False) -> Dict:

    results = await asyncio.gather(
        *tasks.values(),
        loop=loop,
        return_exceptions=return_exceptions
    )
    return dict(zip(tasks.keys(), results))

关于如何以更简单的方式做到这一点的任何想法？谢谢!!!

Answer 1

我重新定义了你的任务，使其更纯粹为协程列表，并且更喜欢从 run_until_complete 方法中获取结果，代码如下，并注意到我在你的睡眠代码中返回了一些东西，在你的代码中，你实际上返回 None 。

import asyncio


async def sleep(seconds):
    print('sleeping for {seconds} seconds'.format(seconds=seconds))
    await asyncio.sleep(seconds)
    print('finished sleeping {seconds} seconds'.format(seconds=seconds))
    return {seconds: 'value of {seconds}'.format(seconds=seconds)}


if __name__ == '__main__':

    loop = asyncio.get_event_loop()

    tasks = [sleep(i) for i in range(1, 5)]

    finished, _ = loop.run_until_complete(
        asyncio.wait(tasks))

    result = {}

    for task in finished:
        result.update(task.result())

    print(result)
    loop.close()