Python 3.5
把@asyncio.coroutine替换为async； 把yield from替换为await
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!")
python3.5
async def hello(): print("Hello world!") r = await asyncio.sleep(1) print("Hello again!")
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 """
参考
