Pythonのスクレイピング(SUUMOから物件情報を取り出す)はうまくいかない

AttributeError                            Traceback (most recent call last)
<ipython-input-49-ccef615dab50> in <module>
     32     soup = BeautifulSoup(c, "html.parser")
     33     summary = soup.find("div",id ='js-bukkenList')
---> 34     houses = summary.find_all('li', class_='cassette js-bukkenCassette')
     35 
     36     for house in houses:

AttributeError: 'NoneType' object has no attribute 'find_all'

!pip install beautifulsoup4
from bs4 import BeautifulSoup
import re
import requests
import time
import pandas as pd
!pip install lxml
print('done')

url = 'https://suumo.jp/jj/common/ichiran/JJ901FC004/?initFlg=1&seniFlg=1&ar=030&ta=13&scTmp=13103&scTmp=13109&scTmp=13110&scTmp=13111&scTmp=13112&scTmp=13113&ct=9999999&cb=0.0&kt=8000&kb=0&xt=9999999&xb=60&md=7%2C8%2C9&md=10%2C11%2C12&md=13&et=7&cn=25&newflg=0&km=1&sc=13103&sc=13109&sc=13110&sc=13111&sc=13112&sc=13113&bs=010&bs=011&bs=020&bs=021&pc=100'
result = requests.get(url)
c = result.content
soup = BeautifulSoup(c,"html.parser")

summary = soup.find("div",{'id':'js-bukkenList'})
body = soup.find("body")
pages = body.find_all("div", {'class':'pagination pagination_set-nav'})
pages_text = str(pages)
pages_split = pages_text.split('</a></li></ol>')
num_pages = int(pages_split[0].split('>')[-1])
print("ページ数＝",num_pages)
urls = []
urls.append(url)

for i in range(num_pages - 1):
    page_num = str(i + 2)
    url_page = url + '&pn=' + page_num
    urls.append(url_page)

data = []

jenre = '' #物件タイプ
name = '' #物件名
price = '' #購入価格
address = '' #住所
station = '' #最寄駅
walk = '' #バス徒歩
area = '' #土地面積
building = '' #建物面積
floor_plan = '' #間取り
monthly = '' #月々の支払い
age = '' #築年数
link = '' #リンク
kanrihi = '' #管理費
shuzenhi = '' #修繕積立費
reform = '' #リフォーム
total_units = '' #総戸数
right_form = '' #権利形態
right_district = '' #用途地域
parking = '' #駐車場

for url in urls:

    result = requests.get(url)
    c = result.content
    soup = BeautifulSoup(c, "html.parser")
    summary = soup.find("div",id ='js-bukkenList')
    houses = summary.find_all('li', class_='cassette js-bukkenCassette')

    for house in houses:            
        jenre = house.find_all('span', class_='ui-pct ui-pct--util1 cassettebox-hpct cassettebox-hpctcat')[0].string
        name = house.find_all("a", class_='js-cassetLinkHref')[0].string
        price = house.find_all('dd', class_="infodatabox-details-txt")[0].string
        address = house.find_all('div', class_='infodatabox-box-txt')[0].string
        station = house.find_all('div', class_='infodatabox-box-txt')[1].string
        walk = house.find_all('div', class_='infodatabox-box-txt')[2].text
        area = house.find_all('dd', class_="infodatabox-details-txt")[2].text

        detail = house.find_all('div', class_='infodatabox-box-txt')[4]
        cols = detail.find_all('dd', class_='infodatabox-details-txt')
        for i in range(len(cols)):
            if len(cols) == 2:
                building = detail.find_all('dd', class_='infodatabox-details-txt')[0].string
                floor_plan = detail.find_all('dd', class_='infodatabox-details-txt')[1].string
            elif len(cols) == 3:
                building = detail.find_all('dd', class_='infodatabox-details-txt')[1].text
                floor_plan = detail.find_all('dd', class_='infodatabox-details-txt')[2].string

        monthly = house.find_all('dd', class_="infodatabox-details-txt")[1].string
        age = house.find_all('div', class_='infodatabox-box-txt')[5].string
        linkbox = house.find('div', class_='cassettebox-action')
        linked = linkbox.find('a')
        links = linked.get('href')
        link = 'https://suumo.jp' + links


        link_child = link + 'bukkengaiyo/'
        result_child = requests.get(link_child)
        c_child = result_child.content
        soup_child = BeautifulSoup(c_child, 'html.parser')
        summary_child = soup_child.find_all('tbody',{'class':'vat tal'})

        try:
            kanrihi = summary_child[0].find_all('td')[5].string.strip('\r\n\t')
            shuzenhi = summary_child[0].find_all('td')[6].string.strip('\r\n\t')
            reform = summary_child[0].find_all('td')[16].contents
            total_units = summary_child[1].find_all('td')[2].string.strip('\r\n\t')
            right_form  = summary_child[1].find_all('td')[5].string.strip('\r\n\t')
            right_district = summary_child[1].find_all('td')[6].string.strip('\r\n\t')
            parking = summary_child[1].find_all('td')[7].string.strip('\r\n\t')    
        except:
            pass

        string = [jenre, name, price, address, station, walk, area, building, floor_plan, monthly, age, link, kanrihi, shuzenhi, reform, total_units, right_form, right_district, parking]
        data.append(string)

    time.sleep(1)

df = pd.DataFrame(data, columns=['物件タイプ','物件名','購入金額','住所','最寄駅','バス徒歩','土地面積','建物面積','間取り','月々支払額','築年数','URL','管理費','修繕積立費','リフォーム','総戸数','権利形態','用途地域','駐車場'])
df.to_csv('suumo_scrape.csv', sep=',', encoding='utf-8', header=True, index=False)