【协程】8、异步和非异步模块混合案例

1、案例：asyncio+不支持异步的模块

# -*- coding: utf-8 -*-
import asyncio
import requests

async def download_image(url):
    # 发送网络请求，下载图片(遇到网络下载图片的IP请求，自动化切换到其他任务)
    print('开始下载:', url)

    loop = asyncio.get_event_loop()
    # requests模块默认不支持异步操作，所以就使用线程池来配合实现了
    future = loop.run_in_executor(None, requests.get, url)

    response = await future
    print('下载完成')

    # 图片保存到本地文件
    file_name = url.rsplit('_')[-1]
    with open(file_name, mode='wb') as file_object:
        file_object.write(response.content)


if __name__ == '__main__':
    url_list = [
        'https://www3.autoimg.cn/newsdfs/g29/M08/0C/7D/744x0_0_autohomecar__ChsEn1_RjU2AO1jtAA4sGWp2UpM697.jpg',
        'https://www2.autoimg.cn/cardfs/product/g28/M00/53/28/744x0_1_autohomecar__ChwFkl_SSVmAFnF-AAYqIYCv_r8614.jpg',
        'https://www3.autoimg.cn/cardfs/product/g25/M02/69/B4/744x0_1_autohomecar__ChsEmF_SSVmAAMjnAAf1rScVfMc975.jpg'
    ]

    tasks = [download_image(url) for url in url_list]

    loop = asyncio.get_event_loop()
    loop.run_until_complete(asyncio.wait(tasks))