asyncio async和await列表推导式实现异步高并发执行

import asyncio
import random
import time

# 需求:有一个crontab调度器，每隔1秒，拉起1个job，要求这些job可以并发爬取网页
async def cron_scheduler():
    page0 = 1
    start = time.time()
    for i in range(10000):
        url0 = "{}/{}".format("https://baidu.com", page0)
        [asyncio.create_task(cron_job(url0)) for i in range(50 )]
        await asyncio.sleep(0)  # 主动让渡线程
    end = time.time()
    print("time:",end-start)

async def cron_job(url):
    n = random.randint(1, 3)  # 模拟下载延迟
    await asyncio.sleep(n)
    print("下载结束：", url)

asyncio.run(cron_scheduler())

　　推导式异步更快