asyncio async和await列表推導式實現異步高併發執行

import asyncio
import random
import time

# 需求:有一個crontab調度器，每隔1秒，拉起1個job，要求這些job可以併發爬取網頁
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)  # 主動讓渡線程
    end = time.time()
    print("time:",end-start)

async def cron_job(url):
    n = random.randint(1, 3)  # 模擬下載延遲
    await asyncio.sleep(n)
    print("下載結束：", url)

asyncio.run(cron_scheduler())

　　推導式異步更快