小言_互联网的博客

跟着知识追寻者学BeautifulSoup，你学不会打不还口，骂不还手

2020-04-01 15:16 258人阅读  评论(0)

一 前言

Beautiful Soup 是一个可以从HTML或XML文件中提取数据的Python库；其强大的提取能力让知识追寻者放弃了使用正则匹配查找HTML节点；Beautifu Soup 其能直接通过HTML标签获取相应的节点，或者通过函数直接获得节点，大大提高了编程人员的开发效率；看完本篇学不会Beautiful Soup ，满天神佛都救不了你；觉得知识追寻者的文章有点意思，关注加点赞谢谢；

二 Beautiful Soup 简单使用

Beautiful Soup 的解释器如下：

解释器 使用示例
Python标准库 BeautifulSoup(markup, “html.parser”)
lxml HTML 解析器 BeautifulSoup(markup, “lxml”)
lxml XML 解析器 BeautifulSoup(markup, “xml”)
html5lib BeautifulSoup(markup, “html5lib”)

本篇的解释器读者可以使用Python标准库或者lxml HTML 解析器都可以；下午中获取标签其实都是获取标签对象，读者谨记；

简要概括下属性的说明:

属性 含义
soup.tag.name 获取标签tag名称
soup.tag.string 获取标签tag文本内容
soup.tag 获取标签tag
soup.tag.attrs 获取标签tag所有属性
soup.tag.attrs[‘class’] 获取标签指定class的属性
soup.tag1.tag2 获取子标签tag2
soup.tag.contents 获取tag所有直接子标签以列表输出
soup.tag.children 获取直接子标签，返回生成器
soup.tag.descendants 获取所有子标签，返回生成器
soup.tag.parent 获取直接父节点
soup.tag.parents 获取祖先节点，返回生成器
soup.tag.next_sibling 获取后一个兄弟节点
soup.tag.previous_sibling 获取前一个兄弟节点
soup.tag.next_siblings 获取后一个兄弟节点，返回生成器
soup.tag.previous_siblings 获取前一个兄弟节点，返回生成器

2.1 格式化HTML

  1. 实例化一个Beautiful Soup 实例，入参是HTML，和html.parser
  2. 调用prettify()方法会格式化HTML文档
# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
print(soup.prettify())

输出结果下，是不是很美观，结构是不是很清楚；而且还补全了缺失的标签</form> , </div>；

<div class="filter-box d-flex align-items-center">
 <form action="" id="seeOriginal">
  <dl class="filter-sort-box d-flex align-items-center">
   <dt>
    排序：
   </dt>
   <dd>
    <a class="btn-filter-sort active" data-report-query="" href="javascript:void(0);" target="_self">
     默认
    </a>
   </dd>
   <dd>
    <a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
     <svg aria-hidden="true" class="icon">
      <use xlink:href="#csdnc-rss">
      </use>
     </svg>
     RSS订阅
    </a>
   </dd>
  </dl>
 </form>
</div>

2.2 获取标签节点

  1. 调用soup.dt 会直接获得第一个匹配到dt标签对象；
# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
# 输出节点 <dt>排序：</dt>
print(soup.dt)

2.3 获取节点文本

soup.dt.string 获得dt标签包含的内容；

# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
# 输出文本内容 排序：
print(soup.dt.string)

2.4获取节点名称

soup.dt.name 直接获得标签dt的名称；

# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
# 输出dt
print(soup.dt.name)

2.5 获得节点对象种类

直接获得标签后使用type方法可以显示出标签类型是<class 'bs4.element.Tag'>

# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
dt = soup.dt
# <class 'bs4.element.Tag'>
print(type(dt))

2.6 获取所有属性

soup.a.attrs 获取匹配到第一个a标签的所有属性；

# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
print(soup.a.attrs)

输出默认匹配第一个a标签的全部属性

{'href': 'javascript:void(0);', 'data-report-query': '', 'class': ['btn-filter-sort', 'active'], 'target': '_self'}

2.7 获取特定属性

soup.a.attrs[‘href’]，获取匹配到第一个a标签的href属性内容

# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
# 输出javascript:void(0);
print(soup.a.attrs['href'])

2.8 获取子节点

soup.form.dd 会获得form标签下第一个dd标签

# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
print(soup.form.dd)

输出

<dd><a class="btn-filter-sort active" data-report-query="" href="javascript:void(0);" target="_self">默认</a></dd>

2.9 获取所有直接子节点

soup.form.contents 将会以列表的形式输出form所有的子标签；

# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
print(soup.form.contents)

输出结果：

['\n', <dl class="filter-sort-box d-flex align-items-center">
<dt>排序：</dt>
<dd><a class="btn-filter-sort active" data-report-query="" href="javascript:void(0);" target="_self">默认</a></dd>
<dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
<svg aria-hidden="true" class="icon">
<use xlink:href="#csdnc-rss"></use>
</svg>RSS订阅</a>
</dd>
</dl>]

2.10 获取直接子节点生成器

soup.svg.children 会获得dd所有子节点的生成器；

# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
for index, child in enumerate(soup.svg.children):
    print(index, child)

输出结果：

0 

1 <use xlink:href="#csdnc-rss"></use>
2

2.11 获取所有子节点生成器

soup.dl.descendants 会获取dl 标签所有的子节点（more than direct child node），

# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
for index, child in enumerate(soup.dl.descendants):
    print(index, child)

输出结果：

0 

1 <dt>排序：</dt>
2 排序：
3 

4 <dd><a class="btn-filter-sort active" data-report-query="" href="javascript:void(0);" target="_self">默认</a></dd>
5 <a class="btn-filter-sort active" data-report-query="" href="javascript:void(0);" target="_self">默认</a>
6 默认
7 

8 <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
<svg aria-hidden="true" class="icon">
<use xlink:href="#csdnc-rss"></use>
</svg>RSS订阅</a>
</dd>
9 <a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
<svg aria-hidden="true" class="icon">
<use xlink:href="#csdnc-rss"></use>
</svg>RSS订阅</a>
10 

11 <svg aria-hidden="true" class="icon">
<use xlink:href="#csdnc-rss"></use>
</svg>
12 

13 <use xlink:href="#csdnc-rss"></use>
14 

15 RSS订阅
16 

17

2.12 获取直接父节点

soup.a.parent 或获取第一个匹配到a标签的父标签对象；

# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
print(soup.a.parent)

输出结果：

<dd><a class="btn-filter-sort active" data-report-query="" href="javascript:void(0);" target="_self">默认</a></dd>

2.13 获取祖先节点生成器

soup.a.parents 会获得第一个匹配到a标签的所有父节点，也就是祖先节点，返回生成器；

# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
for node in soup.a.parents:
    if node is None:
        print(node)
    else:
        print(node.name)

输出结果：

dd
dl
form
div
[document]

2.14 获取兄弟节点

兄弟节点有个坑，通常是返回空白，就不做过多讲解

# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
print(soup.dt.next_sibling)

输出是空白；其它兄弟节点属性就不写了，感觉没啥意义，不是空白就是None；

三 搜索文档

学完第二节内容，读者们其实就是打了个基础，重点是这章节；

函数 含义
find_all(name=None, attrs={}, recursive=True, text=None, limit=None, **kwargs) 查找所有匹配节点
find(name=None, attrs={}, recursive=True, text=None, **kwargs) 查找第一个匹配节点
find_parent(name=None, attrs={}, **kwargs) 返回当前节点的父辈节
find_parents(name=None, attrs={}, **kwargs) 返回当前节点的祖先节点
find_next_sibling(name=None, attrs={}, text=None, **kwargs) 返回符合条件的后面的第一个tag节点
find_next_siblings(name=None, attrs={}, text=None, **kwargs) 返回所有符合条件的后面的兄弟节点
find_previous_sibling(self, name=None, attrs={}, text=None, **kwargs) 返回第一个符合条件的前面的兄弟节点
find_previous_siblings(self, name=None, attrs={}, text=None, **kwargs) 返回所有符合条件的前面的兄弟节点
find_next(name=None, attrs={}, text=None, **kwargs) 返回第一个符合条件的节点
find_all_next(name=None, attrs={}, text=None, limit=None, **kwargs) 返回所有符合条件的节点
find_previous(name=None, attrs={}, text=None, **kwargs) 返回第一个符合条件的节点
find_all_previousname=None, attrs={}, text=None, limit=None, **kwargs) 返回所有符合条件的节点
  1. name 表示输出的tag名称
  2. attrs 表示指定属性查找
  3. recursive 表示是否递归所有子节点，默认是；设置为false返回直接子节点
  4. limit 表示 限制 输出数量
  5. **kwargs 可以指定经常出现的属性搜索，比如 id = ‘zszxz’
  6. text 是过滤条件

本节着重讲解find_all方法，find方法于find_all一致，学一个就会用另一个；

3.1 name参数示例

soup.find_all(name=‘dd’) 会获得所有dd标签对象，并且返回列表；

# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
print(soup.find_all(name='dd'))

输出结果

[<dd><a class="btn-filter-sort active" data-report-query="" href="javascript:void(0);" target="_self">默认</a></dd>, <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
<svg aria-hidden="true" class="icon">
<use xlink:href="#csdnc-rss"></use>
</svg>RSS订阅</a>
</dd>]

注：soup.find_all(name=‘dd’) 与 soup.find_all(‘dd’) 一致；

3.2 attrs 属性示例

soup.find_all(attrs={‘id’:‘seeOriginal’}) 获取 属性 id = seeOriginal 所有标签对象

# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
print(soup.find_all(attrs={'id':'seeOriginal'}))

输出

[<form action="" id="seeOriginal">
<dl class="filter-sort-box d-flex align-items-center">
<dt>排序：</dt>
<dd><a class="btn-filter-sort active" data-report-query="" href="javascript:void(0);" target="_self">默认</a></dd>
<dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
<svg aria-hidden="true" class="icon">
<use xlink:href="#csdnc-rss"></use>
</svg>RSS订阅</a>
</dd>
</dl></form>]

3.3 recursive 示例

soup.find_all('dl',recursive=False) 会查找dl标签子节点，当recursive 设置为False之后就找不到了；

# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
print(soup.find_all('dl',recursive=False))

输出空列表[]

3.4limit示例

soup.find_all('dd',limit=1)会限制输出结果为一条

# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
print(soup.find_all('dd',limit=1))

输出

[<dd><a class="btn-filter-sort active" data-report-query="" href="javascript:void(0);" target="_self">默认</a></dd>]

3.5 kwargs 示例之属性匹配

soup.find_all(id='seeOriginal')直接指定id属性查找

# -*- coding: utf-8 -*-
import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
print(soup.find_all(id='seeOriginal'))

输出

[<form action="" id="seeOriginal">
<dl class="filter-sort-box d-flex align-items-center">
<dt>排序：</dt>
<dd><a class="btn-filter-sort active" data-report-query="" href="javascript:void(0);" target="_self">默认</a></dd>
<dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
<svg aria-hidden="true" class="icon">
<use xlink:href="#csdnc-rss"></use>
</svg>RSS订阅</a>
</dd>
</dl></form>]

3.6 kwargs 示例之正则匹配

soup.find_all(href=re.compile("java.*?"))匹配属性 href 正则 java开头的属性标签；

# -*- coding: utf-8 -*-
import re

import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
print(soup.find_all(href=re.compile("java.*?")))

输出结果

[<a class="btn-filter-sort active" data-report-query="" href="javascript:void(0);" target="_self">默认</a>]

3.7 按CSS搜索

soup.find_all("a", class_="btn") 查找a标签，class属性带有btn

# -*- coding: utf-8 -*-
import re

import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
print(soup.find_all("a", class_="btn"))

输出结果

[<a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
<svg aria-hidden="true" class="icon">
<use xlink:href="#csdnc-rss"></use>
</svg>RSS订阅</a>]

四CSS选择器

Beautiful Soup 还直接支持CSS选择器搜索，下面列出了经常使用的方法示例；

# -*- coding: utf-8 -*-
import re

import requests
from bs4 import BeautifulSoup

html = """
    <div class="filter-box d-flex align-items-center">
    <form action="" id=seeOriginal>
    <dl class="filter-sort-box d-flex align-items-center">
    <dt>排序：</dt>
    <dd><a href="javascript:void(0);" data-report-query="" class="btn-filter-sort active" target="_self">默认</a></dd>
    <dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
		<svg class="icon" aria-hidden="true">
			<use xlink:href="#csdnc-rss"></use>
		</svg>RSS订阅</a>
    </dd>
  </dl>"""

# 初始化 soup
soup = BeautifulSoup(html,'html.parser')
# 选取 dl 标签下面的 dt标签
lt = soup.select('dl dt')
print(lt)
dd = soup.select('dl dd')
print(dd[0])
# id 选择器搜索
id = soup.select('#seeOriginal')
print(id)
# class选择器 搜索
cla = soup.select('.btn-filter-sort')
print(cla[0])

分别输出如下

soup.select(‘dl dt’)

[<dt>排序：</dt>]

soup.select(‘dl dd’)[0]

<dd><a class="btn-filter-sort active" data-report-query="" href="javascript:void(0);" target="_self">默认</a></dd>

soup.select(’#seeOriginal’)

[<form action="" id="seeOriginal">
<dl class="filter-sort-box d-flex align-items-center">
<dt>排序：</dt>
<dd><a class="btn-filter-sort active" data-report-query="" href="javascript:void(0);" target="_self">默认</a></dd>
<dd><a class="btn btn-sm rss" href="https://blog.csdn.net/youku1327/rss/list">
<svg aria-hidden="true" class="icon">
<use xlink:href="#csdnc-rss"></use>
</svg>RSS订阅</a>
</dd>
</dl></form>]

soup.select(’.btn-filter-sort’)[0]

<a class="btn-filter-sort active" data-report-query="" href="javascript:void(0);" target="_self">默认</a>


转载：https://blog.csdn.net/youku1327/article/details/104028496
查看评论
* 以上用户言论只代表其个人观点，不代表本网站的观点或立场