python正则表达式爬取博客标题

import requests
import re

headers={'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36'}
for i in range(1,8):
    link='https://blog.youkuaiyun.com/lws123253/article/list/'+str(i)+'?'
    #第一页地址：https://blog.youkuaiyun.com/lws123253/article/list/1?
    #最后一页地址：https://blog.youkuaiyun.com/lws123253/article/list/7?
    r=requests.get(link,headers=headers)
    title_list=re.findall('<span class=.*?</span>(.*?)</a>',r.text)#中间的(.*？)表示提取匹配到内容的括号内部分
    for title in title_list:
        print(title.strip())