from concurrent import futures
# 设置最大线程为30
ex = futures.ThreadPoolExecutor(max_workers=30)
# 提交子程序和子程序参数，没有可空
ex.submit(fn,args..)

for x in url_list1:
    html_data = get_data(x)
    for y in range(0,68):
        try:
            img_url = html_data[y][0]
            img_name = html_data[y][1]
            ex.submit(download_file,img_url,img_name)
        except:
            print('Stoping..')