# 需要的库
import requests
import re
import os
from multiprocessing import Pool
# 请求头
headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36'
}

# 主函数
def get_img(url):
    # 定义图片存储路径
    img_path = './img/'
    if not os.path.exists(img_path):
        os.mkdir(img_path)
    try:
        # 请求网页
        response = requests.get(url=url,headers=headers)
        # 正则提取图片地址
        response = re.findall('<div class="thumb".*?<img src="(.*?)".*?</a>',response.text,re.S)
        # 循环图片地址
        for i in response:
            # 拼接完整图片路由
            url = ('http:' + i)
            # 请求完整图片路由
            response = requests.get(url,headers)
            # 图片命名
            img_name = url.split('/')[-1]
            # 判断图片是否已下载
            if os.path.exists(img_path+img_name):
                print('图片已存在')
            else:
                # 下载图片
                with open(img_path+img_name,'wb') as f:
                    f.write(response.content)
                    print('正在下载：'+url)
    except Exception as e:
        print(e)
# 程序主入口
if __name__ == '__main__':
    # 构造所有ip地址
    urls = ['https://www.qiushibaike.com/imgrank/page/{}/'.format(i) for i in range(1,14)]
    # 使用多进程
    pool = Pool()
    # 开启多进程爬取
    pool.map(get_img,urls)
    print('下载完毕')