[Python知识库]Python学习笔记：27 多线程

多线程是一个可以提高程序运行效率的方法。一些按顺序执行的程序可以使用多线程实现并行执行，从而提高整体效率。

想要了解更多关于多线程的知识请点击：多线程

实例

简单使用

import time
from concurrent.futures import ThreadPoolExecutor


def new_sleep(name):
    print(f'任务{name}休眠开始')
    time.sleep(5)
    print(f'任务{name}休眠完成')


def main():
    # for i in range(1, 4):
    #     new_sleep(i)
    # 引入线程池
    with ThreadPoolExecutor(max_workers=2) as pool:
        for i in range(1, 4):
            # 调用的任务必须是函数
            pool.submit(new_sleep, i)


if __name__ == '__main__':
    start = time.time()
    main()
    end = time.time()
    print(f'用时：{end - start}')

360图片下载

import requests
import time
import json
from concurrent.futures import ThreadPoolExecutor


def download_img(href, num):
    resp = requests.get(href)
    with open(f'img/{num}.jpg', 'wb') as file:
        file.write(resp.content)


def main():
    count = 0
    for i in range(0, 90, 30):
        url = f'https://image.so.com/zjl?ch=wallpaper&sn={i}'
        resp = requests.get(url)
        data = json.loads(resp.text)
        # 单线程
        # for j in data['list']:
        #     count += 1
        #     print(j['imgurl'])
        #     download_img(j['imgurl'], count)

        # 多线程
        with ThreadPoolExecutor(max_workers=16) as pool:
            for j in data['list']:
                count += 1
                pool.submit(download_img, j['imgurl'], count)


if __name__ == '__main__':
    start = time.time()
    main()
    end = time.time()
    print(f'用时：{end - start}')