线程实现多任务

from threading import Thread
from urllib import request

def downloader(url):
    file_name = url.split('/')[-1]

    response = request.urlopen(url)
    content = response.read()

    with open(file_name,'wb') as fp:
        fp.write(content)
    print('子线程任务完成！')

if __name__ == '__main__':
    #主进程下面有一个主线程

    url_list = [
        'http://www.langlang2017.com/img/logo.png',
        'http://www.langlang2017.com/img/langlang1.png'
    ]


    #创建线程
    thread_list = []
    for url in url_list:
        t = Thread(target=downloader,args=(url,))
        t.start()#启动线程
        thread_list.append(t)

    for t in thread_list:
        t.join()



    print('~~~~~~主线程执行完成~~~~~~~')