xpath 操作

 导包
 import requests
 from lxml import etree

 headers = {
     'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.70 Safari/537.36'
 }
 res = requests.get(url='https://www.tuli.cc/index.html', headers=headers)

 实例化对象
 tree = etree.HTML(res.text)
 ret = tree.xpath('//*[@id="img-container"]/div[6]/div/div/div[1]/a/img')  # 结果为一个列表, 列表中的元素是字符串节点对象
 ret_src = ret[0].xpath('./@src')
 print(ret_src)

 1) /: 根节点
 2) //: 任意位置
 3) .: 当前节点
 4) nodename: 节点名定位, *代表任意节点名
 5) 节点属性定位: 节点名[@属性名="divtag "]    div[@id="divtag"]
 6) 获取节点的属性: @属性名
 7) 获取节点文本: text()

单数属性多值匹配  & 多属性匹配
1).单属性多值: <div class="divtag clear"></div><div class="divtag clear item"></div>
contains函数: tree.xpath('//div[contains(@class, "divtag")]')
2).多属性匹配: <div class="divtag" name="item"></div> <div class="divtag"></div>
and关键字: tree.xpath('//div[@class="divtag" and name="item"]')

 按序选择:
 1).索引定位: 注意一下, xpath的索引从1开始
 2).last()函数: 定位最后一个
 3).position()函数: 位置函数, 确定节点的位置

案例:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Xpath练习文件</title>
</head>
<body>
<div id="007">
    "我是div标签的文字内容, 和下面的p标签还有div标签是同级的哦"
    <p>这是p标签内的文字内容</p>
    <div>这是p标签同级的div标签</div>
</div>

<div class="divtag">
    <ul>
        <li>第1个li标签</li>
        <li>第2个li标签</li>
        <li>第3个li标签</li>
        <li>第4个li标签</li>
        <li>第5个li标签</li>
    </ul>
    <a href="https://www.baidu.com">这是百度的跳转连接</a>
</div>


<div class="c1" name="laoda">老大在此</div>
<div class="c1 c3" name="laoer">老二任性, class有两个值</div>
<div class="c1" name="laosan">我是老三</div>

<div id="112">
    <div>
        <h1>lsdjfihlfdjofjwjbcl</h1>
        <span>就返回使得开发</span>
    </div>
    <div>
        <h1>lsdjfihlfdjofjwjbcl</h1>
        <span>你好</span>
    </div>
    <div>
        <h1>lsdjfihlfdjofjwjbcl</h1>
        <span>我好</span>
    </div>
    <div>
        <h1>lsdjfihlfdjofjwjbcl</h1>
        <span>他好</span>
    </div>
    <div>
        <h1>lsdjfihlfdjofjwjbcl</h1>
        <span>都挺好</span>
    </div>
</div>

</body>
</html>
from lxml import etree

tree = etree.parse('./xpath_test.html', etree.HTMLParser())
# //为任意位置, 节点名定位
ret1 = tree.xpath('//title/text()')

# 根据节点属性定位
ret2 = tree.xpath('//div[@id="007"]/text()')
# print(ret2)
ret3 = tree.xpath('//div[@id="007"]//text()')
# print(ret3)

# 获取属性
ret4 = tree.xpath('//div[@class="divtag"]/a/@href')
# print(ret4)

# .: ./ .//
# skdfjlksdjf-都挺好
div_list = tree.xpath('//div[@id="112"]/div')
for div in div_list:
    first = div.xpath('.//h1/text()')[0]
    second = div.xpath('./span/text()')[0]
    # print('%s-----%s' % (first, second))

# 单属性多值
ret5 = tree.xpath('//div[contains(@class, "c1")]/text()')
print(ret5)

# 多属性匹配
ret6 = tree.xpath('//div[@class="c1" and @name="laosan"]/text()')
print(ret6)

ret7 = tree.xpath('//div[@class="divtag"]/ul/li[last()-1]/text()')
# print(ret7)

ret8 = tree.xpath('//div[@class="divtag"]/ul/li[position()>2 and position()<5]/text()')
print(ret8)

ret9 = tree.xpath('//div[@class="divtag"]/ul/li[position()<3 or position()>4]/text()')
print(ret9)
原文地址:https://www.cnblogs.com/gaodenghan/p/13626704.html