score = li.xpath('@data-score')[0] IndexError: list index out of range 报错，如何解决

import requests

from lxml import etree

from urllib import request

headers = {
'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.87 Safari/537.36',
'Referer': 'https://movie.douban.com/'
}

url = 'https://movie.douban.com/cinema/nowplaying/zhengzhou/'
response = requests.get(url,headers=headers)

text = response.text

html = etree.HTML(text)
ul = html.xpath("//ul[@class='lists']")[0]

lis = ul.xpath("./li")

fns_num = 1
num = len(lis)

for li in lis:

  title = li.xpath('@data-title')[0]

  score = li.xpath('@data-score')[0]

  poster = li.xpath('.//img/@src')[0]


   request.urlretrieve(poster, 'D:/A/' + score + title + '.jpg')
   print("\r完成进度: {:.2f}%".format(fns_num * 100 / num), end="")
   fns_num += 1

score = li.xpath('@data-score')获取的为空，所以不能用 score[0] 来获取数据