xpath是一门在HTML/XML中查找信息的语言，Python的lxml库引入了xpath。在Python中引入lxml就可以解析HTML

安装

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pip install lxml

基础应用

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from lxml import etree # 导入xpath
# etree.XML(content)  # 解析xml文档
# etree.HTML(content)  # 解析html文档
# etree.parse(path)  # 通过传入路径解析文件

# 一段xml文档
xml="‘’
<book>
    <id>1</id>
    <name>野花遍地香</name>
    <sprice>1.23</price>
    <nick>臭豆腐</nick>
    <author>
        <nick id="10086">周大强</nick>
        <nick id="10010">周星驰</nick>
        <nick class="jay">周杰伦</nick>
        <nick class="jolin">蔡依林</nick>
        <div>
            <nick>明星</nick>
        </div>
        <span>
            <nick>演员</nick>
        </span>
        </author>
    <partner>
        <nick id="ppc">胖胖陈</nick>enick id="ppbc">胖胖不陈</nick>
    </partner>
</book>
“‘”
tree = etree.XML(xml)  # 解析xml文档

# 查找节点
result = tree.xpath("/book/name")  # 找到name节点

# 查找节点中的文字
result = tree.xpath("/book/name/text()")  # ['野花遍地香']
result = tree.xpath("/book/name/author/nick/text()") # ['周大强','周星驰','周杰伦','蔡依林']
# 找到周大强
result = tree.xpath("/book/name/author/nick[1]/text()") # ['周大强']
# 找class为jay的节点文字
result = tree.xpath("/book/name/author/nick[@class='jay']/text()") # ['周杰伦']
# 查找属性值
result = tree.xpath("/book/name/author/nick/@class") # ['jay','jolin']

# 两个//表示所有子节点和孙子节点。*表示通配符
# 查找author节点下所有nick节点中的文字。
result = tree.xpath("/book/name/author//nick/text()")  # ['周大强','周星驰','周杰伦','蔡依林','明星']
# 找到文字：明星和演员
result = tree.xpath("/book/name/author/*/nick/text()")  # ['明星','演员']

# 定位，position
# 查找的位置大于2，也就是从第3个开始
tree.xpath("/book/name/author//nick[position()>3]/text()")  # ['周杰伦','蔡依林','明星']