求问 xpath爬取58二手房标题为什么结果为空啊

# coding:utf-8
"爬取58二手房中的房源信息"
from lxml import etree
import requests
if __name__ == '__main__':
    # 获取源码
    url = 'https://hrb.58.com/nangang/ershoufang/'
    headers = {
        'user - agent':  'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.101 Safari/537.36'
    }
    response = requests.get(url=url,headers=headers)
    response.encoding = 'utf-8'
    page_text = response.text
    # 数据解析
    tree = etree.HTML('page_text',etree.HTMLParser())
    # 获取整个数据
    div_list = tree.xpath('//section[@class="list"]/div')
    # 创建文件
    fp = open('./58二手房.txt','w',encoding='utf-8')
    # 获取数据
    for i in div_list:
        title_page = i.xpath('./a/div[2]/div/div/h3/text()')[0]
        print(title_page)
        fp.write(title_page+'\n')

添加爬取网页信息：