利用协程框架批量下载网页内容，看看效果吧

import  time
import  asyncio

async def down(url):
    print("你好，开始下载")
    await  asyncio.sleep(3)
    print("你好，下载完成")


async def main():
    urls =[
        'www.baidu.com',
        'www.google.com'
        'www.163.com'
    ]
    masks=[]
    for url in urls:
        p= down(url)
        masks.append(p)
    done,pending=await asyncio.wait(masks)
    for task in done:
        print(f"{task}已完成下载")

if __name__ == '__main__':
    t1=time.time()
    asyncio.run(main())
    t2=time.time()
    print(t2-t1)