Python 3.5

把@asyncio.coroutine替换为async；
把yield from替换为await
  

 

  
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用asyncio提供的@asyncio.coroutine可以把一个generator标记为coroutine类型，然后在coroutine内部用yield from调用另一个coroutine实现异步操作。

以下两种写法等价

@asyncio.coroutine
def hello(): print("Hello world!") r = yield from asyncio.sleep(1) print("Hello again!")
  

 

  
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python3.5

async def hello(): print("Hello world!") r = await asyncio.sleep(1) print("Hello again!")
  

 

  
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协程示例

import asyncio
import time

now = lambda : time.time()

async def hello(): print("hello") await asyncio.sleep(2) return "done"

start = now()

# 协程对象
h1 = hello()
h2 = hello()
h3 = hello()

# 创建一个事件loop
loop = asyncio.get_event_loop()

# 任务（task）对象
tasks = [ asyncio.ensure_future(h1), asyncio.ensure_future(h2), asyncio.ensure_future(h3),
]

# 将协程加入到事件循环loop
loop.run_until_complete(asyncio.wait(tasks))

for task in tasks: print(task.result())

print(now()-start)
"""
hello
hello
hello
done
done
done
2.005011796951294
"""


  

 

  
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参考

1. 廖雪峰pyhton -async/await
2. python中重要的模块–asyncio

文章来源: pengshiyu.blog.csdn.net，作者：彭世瑜，版权归原作者所有，如需转载，请联系作者。

原文链接：pengshiyu.blog.csdn.net/article/details/80762698