为什么爬取的页面格式和网页的不一样？

源代码

#利用cookie存储做一个模拟登录
import requests
from lxml import etree
import ddddocr
import time
if __name__ == '__main__':
    #创建一个session对象
    session = requests.Session()
    headers = {
        'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3947.100 Safari/537.36'
    }
    url = 'http://www.zjnep.com/lms/web/default/login'
    page_text = requests.get(url=url,headers=headers).text
    tree = etree.HTML(page_text)
    code_img_src = 'http://www.zjnep.com' + tree.xpath('//*[@id="imgCode"]/@src')[0]
    print(code_img_src)
    code_img_data = requests.get(url=code_img_src,headers=headers).content
    with open('./code.jpg','wb') as fp:
        fp.write(code_img_data)



    begin = time.time()
    ocr = ddddocr.DdddOcr()

    with open('code.jpg', 'rb') as f:
        img_bytes = f.read()

    res = ocr.classification(img_bytes)
    finish = time.time()
    print("结果：")
    print(res)
    print("用时：%s 秒" % str(finish - begin))


    #post请求的发送(模拟登录)
    #   -login里面找到post请求
    logincheck_url = 'http://www.zjnep.com/lms/web/default/login'
    data = {
       ' _csrf': 'B_a2FMTuS1ajuVWzxeqWaue1LMBkmSb-HqN-BZYJanQxxfNkp58tZcT_GePyreciq8dHhgPrcc9O-RJLzHw9MA==',
        'LoginForm[userid]': '43022320010501919X',
       'LoginForm[password]': '01919X',
        'veri_code': res
    }
    response = session.post(url=logincheck_url,headers=headers,data=data)
    print(response.status_code)

    #爬取个人主页页面的数据
    detail_url = 'http://www.zjnep.com/lms/web/course/index'
    detail_page_text = session.get(url=detail_url,headers=headers).text
    with open('wdkc.html','w',encoding='utf-8') as f:
        f.write(detail_page_text)

爬取的页面

img