本案例用到列表，函数，字符串等知识点，知识点参考链接如下：
python基础知识（一）&输入输出函数
python基础知识（二）&基本命令
python基础知识（三）&常用的内置函数
python基础知识（四）&符串常用的方法
python基础知识（六）&字典
python基础知识（七）& 列表
python基础知识（八）&open函数
python基础知识（九）&函数

完整代码如下：

# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup
import pandas as pd
import csv

def qingqiu(url):
    rq = requests.get(url, headers=headers)
    html = rq.text
    return html

def paser_html(html):
    bs=BeautifulSoup(html,"lxml")
    price_all=[]
    price=bs.select('span[class=""]')
    for p in price:
        price_all.append(float(p.get_text()))

    danjia_all=[]
    danjia=bs.select('div[class="unitPrice"]')
    for d in danjia:
        danjia_all.append(d.get_text().replace("元/平",""))

    loupan_all=[]
    loupan=bs.select('a[data-el="region"]')
    for l in loupan:
        loupan_all.append(l.get_text())

    all=bs.select('div[class="houseInfo"]')
    all_data=[]
    for a in all:
        all_data.append(a.get_text().split('|'))
    huxing=[]
    size=[]
    fangxiang=[]
    zhuangxiu=[]
    louceng=[]
    for i in all_data:
        huxing.append(i[0])
        size.append(float(i[1].replace("平米","")))
        fangxiang.append(i[2])
        zhuangxiu.append(i[3])
        louceng.append(i[4])
    result=zip(loupan_all,danjia_all,price_all,huxing,size,fangxiang,zhuangxiu,louceng)
    return result

def save(result):  # 保存
    with open('长沙二手房.csv', "a", newline='', encoding='utf-8') as f:
        wr = csv.writer(f)
        for a in result:
            wr.writerow(a)

if __name__ == '__main__':
    T_head = ['楼盘', '单价', '总价', '户型', '面积', '方向', '装修','楼层']
    with open('长沙二手房.csv', "a", newline='', encoding='utf-8') as f:
        wr = csv.writer(f)
        wr.writerow(T_head)

    start_ye = int(input("请输入起始页："))
    end_ye = int(input("请输入终止页："))
    for y in range(start_ye, end_ye):
        url='https://cs.lianjia.com/ershoufang/pg{}/'.format(y)
        headers = {'User-Agent':'Mozilla/5.0'}
        html=qingqiu(url)
        result=paser_html(html)
        save(result)
        print("爬取第{}页".format(y))

运行后保存的数据如下表所示：