xpath案例-4K图片爬取

#!/usr/bin/python

#需求：解析下载图片数据 http://pic.netbian.com/4kmeinv/
import requests
from lxml import etree 
import os
if __name__ == "__main__":
    url = 'http://pic.netbian.com/4kmeinv/'
    headers = {
        'User-Agent':'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2626.106 Safari/537.36'
    }

    response = requests.get(url=url,headers=headers)
    #可以手动设定响应数据的编码格式
    # response.encoding = 'utf-8'
    page_text = response.text

    #数据解析:src的属性值 alt属性
    tree = etree.HTML(page_text)
    li_list = tree.xpath('//div[@class="slist"]/ul/li')
    # print(li_list)
    
    #创建一个文件夹
    if not os.path.exists('./picLibs'):
        os.mkdir('./picLibs')


    for li in li_list:
        img_src = 'http://pic.netbian.com'+li.xpath('./a/img/@src')[0]
        img_name = li.xpath('./a/img/@alt')[0]+'.jpg'
        #通用处理处理中文乱码的解决方案
        img_name = img_name.encode('iso-8859-1').decode('gbk')
        # print(img_name,img_src)
        #请求图片进行持久化存储
        img_data = requests.get(url=img_src,headers=headers).content
        
        img_path = 'picLibs/'+img_name

        with open(img_path,'wb') as fp:
            fp.write(img_data)
            print(img_name,'下载成功!!!')