python 事件机制asyncio(并行编程 25)

loop=get_event_loop() 当前上下文的事件循环

loop.call_later(time_delay,callback,arg)

loop.call_soon(callback,agr)

asyncio.set_event_loop() 设定上下文事件循环

asyncio.new_event_loop() 创建

loop.run_forever()

异步函数：

import time import asyncio

定义异步函数

async def hello(): print('Hello World:%s' % time.time())

def run(): for i in range(5): loop.run_until_complete(hello())

loop = asyncio.get_event_loop() if name =='main': run()

输出结果：

Hello World:1562248241.350658 Hello World:1562248241.350658 Hello World:1562248241.350658 Hello World:1562248241.350658 Hello World:1562248241.350658

异步requests库:aiohttp

import asyncio from aiohttp import ClientSession

tasks = [] url = "https://www.baidu.com/{}" async def hello(url): async with ClientSession() as session: async with session.get(url) as response: response = await response.read() print(response)

if name == 'main': loop = asyncio.get_event_loop() loop.run_until_complete(hello(url))

import asyncio

async def main(): print('Hello ...') await asyncio.sleep(1) print('... World!')

Python 3.7+

asyncio.run(main())