四个Python爬虫案例,带你掌握xpath数据解析方法!_python

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文章目录

  • xpath基本概念
  • xpath解析原理
  • 环境安装
  • 如何实例化一个etree对象:
  • xpath(‘xpath表达式’)
  • xpath爬取58二手房实例
  • 爬取网址
  • 完整代码
  • 效果图
  • xpath图片解析下载实例
  • 爬取网址
  • 完整代码
  • 效果图
  • xpath爬取全国城市名称实例
  • 爬取网址
  • 完整代码
  • 效果图
  • xpath爬取简历模板实例
  • 爬取网址
  • 完整代码
  • 效果图

xpath基本概念

xpath解析:最常用且最便捷高效的一种解析方式。通用性强。

xpath解析原理

1.实例化一个etree的对象,且需要将被解析的页面源码数据加载到该对象中

2.调用etree对象中的xpath方法结合xpath表达式实现标签的定位和内容的捕获。

环境安装

pip install lxml

如何实例化一个etree对象:

from lxml import etree

1.将本地的html文件中的远吗数据加载到etree对象中:

etree.parse(filePath)

2.可以将从互联网上获取的原码数据加载到该对象中:

etree.HTML(‘page_text’)

xpath(‘xpath表达式’)

  • /:表示的是从根节点开始定位。表示一个层级
  • //:表示多个层级。可以表示从任意位置开始定位
  • 属性定位://div[@class='song'] tag[@attrName='attrValue']
  • 索引定位://div[@class='song']/p[3] 索引从1开始的
  • 取文本:
  • /text()获取的是标签中直系的文本内容
  • //text()标签中非直系的文本内容(所有文本内容)
  • 取属性:/@attrName ==>img/src

xpath爬取58二手房实例

爬取网址

https://xa.58.com/ershoufang/完整代码

from lxml import etree
import requests

if __name__ == '__main__':
headers = {
'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.105 Safari/537.36'
}
url = 'https://xa.58.com/ershoufang/'
page_text = requests.get(url=url,headers=headers).text
tree = etree.HTML(page_text)
div_list = tree.xpath('//section[@class="list"]/div')
fp = open('./58同城二手房.txt','w',encoding='utf-8')
for div in div_list:
title = div.xpath('.//div[@class="property-content-title"]/h3/text()')[0]
print(title)
fp.write(title+'\n'+'\n')

四个Python爬虫案例,带你掌握xpath数据解析方法!_python_02

xpath图片解析下载实例

爬取网址

https://pic.netbian.com/4kmeinv/完整代码

import requests,os
from lxml import etree

if __name__ == '__main__':
headers = {
'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.105 Safari/537.36'
}
url = 'https://pic.netbian.com/4kmeinv/'
page_text = requests.get(url=url,headers=headers).text
tree = etree.HTML(page_text)
li_list = tree.xpath('//div[@class="slist"]/ul/li/a')
if not os.path.exists('./piclibs'):
os.mkdir('./piclibs')
for li in li_list:
detail_url ='https://pic.netbian.com' + li.xpath('./img/@src')[0]
detail_name = li.xpath('./img/@alt')[0]+'.jpg'
detail_name = detail_name.encode('iso-8859-1').decode('GBK')
detail_path = './piclibs/' + detail_name
detail_data = requests.get(url=detail_url, headers=headers).content
with open(detail_path,'wb') as fp:
fp.write(detail_data)
print(detail_name,'seccess!!')

四个Python爬虫案例,带你掌握xpath数据解析方法!_xpath_03

xpath爬取全国城市名称实例

爬取网址 

https://www.aqistudy.cn/historydata/完整代码

import requests
from lxml import etree

if __name__ == '__main__':
url = 'https://www.aqistudy.cn/historydata/'
headers = {
'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.141 Safari/537.36',
}
page_text = requests.get(url=url,headers=headers).content.decode('utf-8')
tree = etree.HTML(page_text)
#热门城市 //div[@class="bottom"]/ul/li
#全部城市 //div[@class="bottom"]/ul/div[2]/li
a_list = tree.xpath('//div[@class="bottom"]/ul/li | //div[@class="bottom"]/ul/div[2]/li')
fp = open('./citys.txt','w',encoding='utf-8')
i = 0
for a in a_list:
city_name = a.xpath('.//a/text()')[0]
fp.write(city_name+'\t')
i=i+1
if i == 6:
i = 0
fp.write('\n')
print('爬取成功')

四个Python爬虫案例,带你掌握xpath数据解析方法!_定位_04

xpath爬取简历模板实例

爬取网址

https://sc.chinaz.com/jianli/free.html完整代码

import requests,os
from lxml import etree

if __name__ == '__main__':
url = 'https://sc.chinaz.com/jianli/free.html'
headers = {
'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.141 Safari/537.36',
}
page_text = requests.get(url=url,headers=headers).content.decode('utf-8')
tree = etree.HTML(page_text)
a_list = tree.xpath('//div[@class="box col3 ws_block"]/a')
if not os.path.exists('./简历模板'):
os.mkdir('./简历模板')
for a in a_list:
detail_url = 'https:'+a.xpath('./@href')[0]
detail_page_text = requests.get(url=detail_url,headers=headers).content.decode('utf-8')
detail_tree = etree.HTML(detail_page_text)
detail_a_list = detail_tree.xpath('//div[@class="clearfix mt20 downlist"]/ul/li[1]/a')
for a in detail_a_list:
download_name = detail_tree.xpath('//div[@class="ppt_tit clearfix"]/h1/text()')[0]
download_url = a.xpath('./@href')[0]
download_data = requests.get(url=download_url,headers=headers).content
download_path = './简历模板/'+download_name+'.rar'
with open(download_path,'wb') as fp:
fp.write(download_data)
print(download_name,'success!!')

四个Python爬虫案例,带你掌握xpath数据解析方法!_定位_05