python 协程嵌套

import asyncio

import time

now = lambda: time.time()

async def do_some_work(x):
    print('Waiting: ', x)

    await asyncio.sleep(x)
    return 'Done after {}s'.format(x)

async def main():
    coroutine1 = do_some_work(1)
    coroutine2 = do_some_work(2)
    coroutine3 = do_some_work(4)

    tasks = [
        asyncio.ensure_future(coroutine1),
        asyncio.ensure_future(coroutine2),
        asyncio.ensure_future(coroutine3)
    ]

    dones, pendings = await asyncio.wait(tasks)

    for task in dones:
        print('Task ret: ', task.result())

start = now()

loop = asyncio.get_event_loop()
loop.run_until_complete(main())

print('TIME: ', now() - start)

如果使用的是 asyncio.gather创建协程对象，那么await的返回值就是协程运行的结果。

    results = await asyncio.gather(*tasks)

    for result in results:
        print('Task ret: ', result)