一个Python爬虫案例，带你掌握xpath数据解析方法！
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')
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!!')
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')
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!!')
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