[Python知识库]python协程

#使用队列与协程结合来进行并发
import asyncio
import time

async def download(delay,what):
    await asyncio.sleep(delay)
    print(what)

async def mutil_download(tlist,n):
    #create_task的动作必须在async函数中
    tasklist = []
    while True:
        if len(tlist)==0:
            break
        for i in range(n):
            #n控制列表中添加任务的数量，也就是并发数
            if len(tlist) !=0:
                #如果列表是空的就不在创建任务
                tlist.pop(0)
                print(tlist)
                #从列表中弹出第一个值
                tasklist.append(asyncio.create_task(download(i+1,'task{}'.format(i))))
                #往tasklist中添加协程任务
        print('start:',time.strftime('%X'))
        for t in tasklist:
            await t
        print('end:',time.strftime('%X'))

if __name__ == '__main__':
    # tasklist = [asyncio.create_task(download(2,'hello')),asyncio.create_task(download(3,'world'))]
    list1 = [1,2,3,4,5,6,7,8,9,0]
    asyncio.run(mutil_download(list1,4))