爬虫Xpath使用
Xpath使用案例
准备工作
pip install lxml
代码如下:
点击查看代码
from lxml import etree
#定义字符串
wb_data = """
<div>
<ul>
<li class="item-0"><a href="link1.html">first item</a></li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-inactive"><a href="link3.html">third item</a></li>
<li class="item-1"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a>
</ul>
</div>
"""
#讲变量读取为html对象，自动添加<html><body>... ...</body></html>
html=etree.HTML(wb_data)
#解析数据,/是跟节点
data1=html.xpath('/html')
for i in data1:
print(i)
#//后面跟子孙节点，后面的节点可以在任意位置
data2=html.xpath('//li')
for i in data2:
print(i)
#写具体路径
data3=html.xpath('/html/body/div/ul/li/a')
for i in data3:
print(i.text)
#循环某个属性
data4=html.xpath('/html/body/div/ul/li/@class')
for i in data4:
print(i)
#.代表当前节点，..代表父节点
data5=html.xpath('/html/body/div/ul/li/a')
for i in data5:
a=i.xpath('./@href')
print(a)
#读取某一个节点
data6=html.xpath('/html/body/div/ul')
for i in data6:
li_1=i.xpath('./li[1]')
print(li_1)
li_last=i.xpath('./li[last()]')
print(li_last)
#带有某属性的标签
data7=html.xpath('//ul/li/a[@href="link2.html"]')
for i in data7:
print(i.text)
#*位置节点
data8=html.xpath('//ul/li/*')
for i in data8:
if hasattr(i,'text'):
print(i.text)
else:
print(i)
