基于lxml.etree实现xpath查找HTML元素
By:授客 QQ：1033553122
#实践环境
WIN 10
Python 3.6.5
lxml-4.6.2-cp36-cp36m-win_amd64.whl
#实践代码
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from lxml import etree
html_str = '''<html>
<body>
<table width="400" border="1">
<tr>
<th align="left">消费项目....</th>
<th align="right">一月</th>
<th align="right">二月</th>
</tr>
<tr>
<td align="left">衣服</td>
<td align="right">$241.10</td>
<td align="right">$50.20</td>
</tr>
<tr>
<td align="left">化妆品</td>
<td align="right">$30.00</td>
<td align="right">$44.45</td>
</tr>
<tr>
<td align="left">食物</td>
<td align="right">$730.40</td>
<td align="right">$650.00</td>
</tr>
<tr>
<th align="left">总计</th>
<th align="right">$1001.50</th>
<th align="right">$744.65</th>
</tr>
</table>
</body>
</html>
'''
root_node = etree.HTML(html_str) # 解析HTML字符串，并返回HTML根结点
print('根节节点名称为：%s' % root_node.tag) # 输出 html
# 查找根节点
print(root_node.xpath('/html')) # 输出 <Element html at 0x17245dc8508>]
tr_element_list = root_node.xpath("//table/tr[2]/td") # 获取table元素节点下，第二个tr元素节点下的所有td元素
for element in tr_element_list:
print(element.tag, element.text)
/* for循环输出如下
td 衣服
td $241.10
td $50.20
*/
etree.tostring(root_node, encoding='utf-8').decode('utf-8') ## 输出节点内容
second_tr = root_node.xpath('//table/tr[2]')[0] # 获取table元素节点下，第二个tr元素节点
print(etree.tostring(second_tr, encoding='utf-8').decode('utf-8')) ## 输出节点内容
/*
<tr>
<td align="left">衣服</td>
<td align="right">$241.10</td>
<td align="right">$50.20</td>
</tr>
*/
# 注意：etree.tostring返回结果为字节对象
print(etree.tostring(second_tr)) ## 输出以下内容
/*
b'<tr>
<td align="left">衣服</td>
<td align="right">$241.10</td>
<td align="right">$50.20</td>
</tr>
'
*/
print(etree.tostring(second_tr).decode('utf-8')) # 输出以下内容
/*
<tr>
<td align="left">衣服</td>
<td align="right">$241.10</td>
<td align="right">$50.20</td>
</tr>
*/
#参考连接
https://lxml.de/tutorial.html#the-element-class
https://lxml.de/tutorial.html#the-xml-function