asyncio

node2:/root/python/20200525#cat t900.py 

import asyncio
import aiohttp
import time

async def download_one(url):
    async with aiohttp.ClientSession() as session:
        async with session.get(url) as resp:
            print('Read {} from {}'.format(resp.content_length, url))

async def download_all(sites):
    tasks = [asyncio.create_task(download_one(site)) for site in sites]
    await asyncio.gather(*tasks)

def main():
    sites = [
    'http://192.168.137.3:9000/test111/',
    'http://192.168.137.3:9000/test222/',
    'http://192.168.137.3:9000/test333/'
    ]
    start_time = time.perf_counter()
    asyncio.run(download_all(sites))
    end_time = time.perf_counter()
    print('Download {} sites in {} seconds'.format(len(sites), end_time - start_time))
    
if __name__ == '__main__':
    main()
node2:/root/python/20200525#python3 t900.py 
Read 75784 from http://192.168.137.3:9000/test111/
Read 66390 from http://192.168.137.3:9000/test222/
Read 65672 from http://192.168.137.3:9000/test333/
Download 3 sites in 7.1168726910836995 seconds
node2:/root/python/20200525#

如果是 I/O bound，并且 I/O 操作很慢，需要很多任务 / 线程协同实现，那么使用 Asyncio 更合适。

如果是 I/O bound，但是 I/O 操作很快，只需要有限数量的任务 / 线程，那么使用多线程就可以了。

如果是 CPU bound，则需要使用多进程来提高程序运行效率