相关疑难解决方法(0)

假设我们有一堆下载链接,每个链接可能需要不同的下载时间.我只允许使用最多3个连接下载.现在,我想确保使用asyncio有效地执行此操作.

这就是我想要实现的目标:在任何时候,尽量确保我至少运行3次下载.

Connection 1: 1---------7---9---
Connection 2: 2---4----6-----
Connection 3: 3-----5---8-----

数字代表下载链接,而连字符代表等待下载.

这是我正在使用的代码

from random import randint
import asyncio

count = 0


async def download(code, permit_download, no_concurrent, downloading_event):
    global count
    downloading_event.set()
    wait_time = randint(1, 3)
    print('downloading {} will take {} second(s)'.format(code, wait_time))
    await asyncio.sleep(wait_time)  # I/O, context will switch to main function
    print('downloaded {}'.format(code))
    count -= 1
    if count < no_concurrent and not permit_download.is_set():
        permit_download.set()


async def main(loop):
    global count
    permit_download = asyncio.Event()
    permit_download.set()
    downloading_event = asyncio.Event()
    no_concurrent = 3 …