asyncio example

asyn.py

import asyncio

@asyncio.coroutine
def hello():
    print("hello start")
    ret = yield from asyncio.sleep(2)
    print('hello end')

@asyncio.coroutine
def world():
    print('world start')
    ret = yield from asyncio.sleep(2)
    print('world end')

if __name__ == '__main__':
    loop = asyncio.get_event_loop()
    tasks = [hello(), world()]
    loop.run_until_complete(asyncio.wait(tasks))
    loop.close()