爬取数据

• 谷歌浏览器安装xpath插件

• 更多 -> 扩展程序 -> 管理扩展程序 -> 开发者模式 -> 加载已解压的扩展程序
  

• 谷歌浏览器任意打开1个网页，F12打开开发者工具，右键右侧a标签区域 -> copy -> copy xpath

• 复制到左上角黑框
  

• 案例1

import pprint
import re
import requests
import parsel
import csv
import time
import traceback
import  sys
from lxml import etree
from utils import  fake_useragent
import random
class LianJia:
    # 构造方法
    def __init__(self):
        self.headers = {
            # "User-Agent": fake_useragent.get_ua()
            "User-Agent": 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36'
        }
        self.f = open("lianjia.csv", mode="w", encoding="utf-8", newline="")

        self.fieldnames =["title",
                          "areaName",
                          "communityName",
                          "hu_xing",
                          "chao_xiang",
                          "lou_ceng",
                          "zhuang_xiu",
                          "dian_ti",
                          "mian_ji"
                          "total"
                          ]

        self.csv_writer = csv.DictWriter(self.f, fieldnames=self.fieldnames, delimiter='\t')
        self.csv_writer.writeheader()

    # 抓取数据
    def getHtml(self):
        for num in range(1, 30):
            time.sleep(random.randint(1, 3))
            url = f"https://cq.lianjia.com/ershoufang/pg{num}/"
            response = requests.get(url=url, headers=self.headers)
            # # 获取源代码
            print( url)
            html = etree.HTML(response.text)
            houselist =self.parseHtml(html)
            self.save_html(houselist)

    def parseHtml(self, html):
        href = html.xpath('//div[@class="title"]/a/@href')
        print( href)
        houselist = []
        for link in href:
            house = {}
            response2 = requests.get(url=link, headers=self.headers)
            # 详情页数据
            # 二次请求
            html2 = etree.HTML(response2.text)
            try:
                # 获取数据
                house['title'] = html2.xpath('//div[@class="sellDetailHeader"]//h1/text()')  # 标题
                house['title'] = house['title'][0] if house['title'] else None
                areaName = html2.xpath('//div[@class="areaName"]/span[2]/a[1]/text()')  # 获取区域 (extract_first())
                house['areaName'] = areaName[0]
                communityName = html2.xpath('//div[@class="communityName"]/a[1]/text()')  # 获取小区名称
                house['communityName'] = communityName[0]
                hu_xing = html2.xpath('//div[@class="base"]/div[@class="content"]/ul/li[1]/text()')  # 获取户型
                house['hu_xing'] = str(hu_xing[1]).strip() if hu_xing else None
                chao_xiang = html2.xpath('//div[@class="base"]/div[@class="content"]/ul/li[7]/text()')  # 获取朝向
                house['chao_xiang'] = str(chao_xiang[1]).strip() if chao_xiang else None
                lou_ceng = html2.xpath('//*[@id="introduction"]/div/div/div[1]/div[2]/ul/li[2]/text()')  # 获取楼层
                house['lou_ceng'] = str(lou_ceng[1]).strip() if lou_ceng else None
                zhuang_xiu = html2.xpath('//*[@id="introduction"]/div/div/div[1]/div[2]/ul/li[9]/text()')  # 获取装修情况
                house['zhuang_xiu'] = str(zhuang_xiu[1]).strip() if zhuang_xiu else None
                dian_ti = html2.xpath('//*[@id="introduction"]/div/div/div[1]/div[2]/ul/li[11]/text()')  # 获取电梯情况
                house['dian_ti'] = str(dian_ti[1]).strip() if dian_ti else None
                mian_ji = html2.xpath('//*[@id="introduction"]/div/div/div[1]/div[2]/ul/li[3]/text()')  # 获取面积
                house['mian_ji'] = str(mian_ji[1]).strip() if mian_ji else None
                total = html2.xpath('/html/body/div[5]/div[2]/div[3]/div/span[1]/text()')  # 获取总价
                house['total'] = total[0]
                print(house)
                houselist.append(house)
            except Exception as err:
                # 获取异常信息
                exc_type, exc_value, exc_traceback = sys.exc_info()

                # 打印异常所在行
                print(f"异常发生在第 {exc_traceback.tb_lineno} 行")

                # 打印异常详细信息
                traceback.print_exception(exc_type, exc_value, exc_traceback)
        # print(houselist)
        # house['title'] = html.xpath('//*[@id="content"]/div[1]/ul/li[1]/div[1]/div[1]/a/text()')  # 标题
        return  houselist

    def save_html(self, houselist):
        if len(houselist )==0:
            return
        print( len(houselist ))
        for row in houselist:
            print( row)
            self.csv_writer.writerow(row)

    def run(self):
        self.getHtml()

if __name__ == '__main__':
    spider = LianJia()
    spider.run()