Python 为什么asyncio.wait不等待第一个\u完成
我是Python3.5Asyncio新手 在我下面的代码中,asyncio.wait()不会等待stop\u future完成:Python 为什么asyncio.wait不等待第一个\u完成,python,future,python-asyncio,event-loop,python-3.5,Python,Future,Python Asyncio,Event Loop,Python 3.5,我是Python3.5Asyncio新手 在我下面的代码中,asyncio.wait()不会等待stop\u future完成: import asyncio import datetime from concurrent.futures import FIRST_COMPLETED def stop(): # callback after 12 seconds print('stop', datetime.datetime.now()) stop_future.set_
import asyncio
import datetime
from concurrent.futures import FIRST_COMPLETED
def stop(): # callback after 12 seconds
print('stop', datetime.datetime.now())
stop_future.set_result('Done!')
async def display_dt():
while not stop_future.done():
print('dt-1', datetime.datetime.now())
# sleep 5 seconds or stop_future done
asyncio.wait([await asyncio.sleep(5), stop_future], return_when=FIRST_COMPLETED)
print('dt-2', datetime.datetime.now())
task = asyncio.Task.current_task()
task.cancel()
print(stop_future.result())
loop = asyncio.get_event_loop()
stop_future = asyncio.Future()
loop.call_later(12, stop)
loop.run_until_complete(display_dt())
loop.close()
结果:
dt-1 2015-11-08 00:49:37.324582
dt-2 2015-11-08 00:49:42.325503
dt-1 2015-11-08 00:49:42.325503
dt-2 2015-11-08 00:49:47.326423
dt-1 2015-11-08 00:49:47.326423
stop 2015-11-08 00:49:49.327192 # async.wait stop_future not triggered
dt-2 2015-11-08 00:49:52.327343 # while loop finishes here
>>> Done!
dt-1 2015-11-08 01:19:06.289915
dt-2 2015-11-08 01:19:11.290836
dt-1 2015-11-08 01:19:11.290836
dt-2 2015-11-08 01:19:16.291757
dt-1 2015-11-08 01:19:16.291757
stop 2015-11-08 01:19:18.292525
dt-2 2015-11-08 01:19:18.292525 # async wait stop_future triggered
Done!
更新:
以下是更新后的功能显示的代码。现在asyncio.wait
工作正常。但我不明白为什么上面的代码与coro不工作
@asyncio.coroutine # decorator necessary? It works fine without
def display_dt():
while not stop_future.done():
print('dt-1', datetime.datetime.now())
yield from asyncio.wait([asyncio.sleep(5), stop_future], return_when=FIRST_COMPLETED)
print('dt-2', datetime.datetime.now())
task = asyncio.Task.current_task()
task.cancel()
print(stop_future.result())
结果:
dt-1 2015-11-08 00:49:37.324582
dt-2 2015-11-08 00:49:42.325503
dt-1 2015-11-08 00:49:42.325503
dt-2 2015-11-08 00:49:47.326423
dt-1 2015-11-08 00:49:47.326423
stop 2015-11-08 00:49:49.327192 # async.wait stop_future not triggered
dt-2 2015-11-08 00:49:52.327343 # while loop finishes here
>>> Done!
dt-1 2015-11-08 01:19:06.289915
dt-2 2015-11-08 01:19:11.290836
dt-1 2015-11-08 01:19:11.290836
dt-2 2015-11-08 01:19:16.291757
dt-1 2015-11-08 01:19:16.291757
stop 2015-11-08 01:19:18.292525
dt-2 2015-11-08 01:19:18.292525 # async wait stop_future triggered
Done!
更新:@asyncio.coroutine#是否需要装饰器
我在以下方面找到了答案:
@asyncio.coroutine装饰程序并不神奇。事实上,如果它装饰了一个生成器函数,并且没有设置PYTHONASYNCIODEBUG环境变量,那么装饰器实际上什么也不做。为了方便框架的其他部分,它只设置了一个属性,_is_coroutine。可以将asyncio与未使用@asyncio.coroutine修饰的裸生成器一起使用。↩ 您必须
等待.wait()
协同程序,而不是等待您传递给.wait()的协同程序:
而不是future.done()
或者这应该是而不是stop\u future.done()
?好的,谢谢。我已将结果更新到您的aswer: