python中利用Future对象回调别的函数示例代码

import asyncio 
import functools 
 
 
def callback(future, n): 
 print('{}: future done: {}'.format(n, future.result())) 
 
 
async def register_callbacks(all_done): 
 print('registering callbacks on future') 
 all_done.add_done_callback(functools.partial(callback, n=1)) 
 all_done.add_done_callback(functools.partial(callback, n=2)) 
 
 
async def main(all_done): 
 await register_callbacks(all_done) 
 print('setting result of future') 
 all_done.set_result('the result') 
 
 
event_loop = asyncio.get_event_loop() 
try: 
 all_done = asyncio.Future() 
 event_loop.run_until_complete(main(all_done)) 
finally: 
 event_loop.close() 

registering callbacks on future
setting result of future
1: future done: the result
2: future done: the result