求助python爬虫代码，请问大佬以下的代码有什么错误，为什么

2301_78871715 2023-10-30 06:57:05

import urllib.request
from lxml import etree
import os

def create_request(page):
    if page == 1:
        url = 'https://sc.chinaz.com/ppt/pptbeijing.html'
    else:
        url = 'https://sc.chinaz.com/ppt/pptbeijing' + str(page) + '.html'

    headers = {'User-Agent':
                   'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36'
               }
    request = urllib.request.Request(url=url, headers=headers)
    return request


def get_content(request):
    try:
        respond = urllib.request.urlopen(request)
        content = respond.read().decode('utf-8')
        return content
    except Exception as e:
        print('请求错误')

def down_load(content):
    tree = etree.HTML(content)
    name_list = tree.xpath('//img[@class="lazy"]/@alt')
    src_list = tree.xpath('//img[@class="lazy"]/@src')

    for i in range(len(name_list)):
        name = name_list[i]
        src = src_list[i]
        url = 'http:' + src
        urllib.request.urlretrieve(url=url, filename='./img/' + name + '.jpg')


if __name__ == '__main__':
    start_page = int(input('请输入起始页数'))
    end_page = int(input('请输入结束页数'))

    for page in range(start_page, end_page + 1):
        request = create_request(page)
        content = get_content(request)
        down_load(content)