Python regular method description for obtaining, filtering or replacing HTML tags

This article mainly introduces Python methods to obtain, filter or replace HTML tags through regular expressions. Interested friends can refer to it Let’s take a look

The example of this article introduces several methods of Python to obtain, remove (filter) or replace HTML tags through regular expressions. The specific content is as follows

python regular expression Key content:

python regular expressionEscape character:

. 匹配除换行符以外的任意字符
\w 匹配字母或数字或下划线或汉字
\s 匹配任意的空白符
\d 匹配数字
\b 匹配单词的开始或结束
^ 匹配字符串的开始
$ 匹配字符串的结束
\W 匹配任意不是字母，数字，下划线，汉字的字符
\S 匹配任意不是空白符的字符
\D 匹配任意非数字的字符
\B 匹配不是单词开头或结束的位置
[^x] 匹配除了x以外的任意字符
[^aeiou] 匹配除了aeiou这几个字母以外的任意字符

Commonly used python regular expression qualifier codes/grammar instructions:

*重复零次或更多次
+重复一次或更多次
?重复零次或一次
{n}重复n次
{n,}重复n次或更多次
{n,m}重复n到m次

About python regular expressions Named group:

命名组:(?P<name>.....)
这篇文章里面还提到了界定( 问号开头,前向则有个&#39;<&#39;号,非则有个&#39;!&#39; 号 ):
前向界定 (?<=…)
后向界定 (?=…) 
前向非界定 (?<!....)
后向非界定 (?!.....)

Python obtains, removes (filters) or replaces HTML tag codes through regular expressions, example

1. Python uses regular expressions to get weather information code example from HTML:

#!/usr/bin/env python 
#-*- coding: utf8 -*- 
import re 
  
html = """ 
  <h2>多云</h2> 
""" 
  
if name == &#39;main&#39;: 
  p = re.compile(&#39;<[^>]+>&#39;) 
  print p.sub("", html)
Python通过正则表达式取html中温度信息代码示例:
#!/usr/bin/env python 
#-*- coding: utf8 -*- 
import re 
  
html = """ 
  <p class="w-number"> <span class="tpte">14℃</span> </p> 
""" 
  
if name == &#39;main&#39;: 
  p = re.compile(&#39;<[^>]+>&#39;) 
  print p.sub("", html)

2. Python removes (filters) HTML tags through regular expressions. Sample code:

##

# -*- coding: utf-8-*-
import re
##过滤HTML中的标签
#将HTML中标签等信息去掉
#@param htmlstr HTML字符串.
def filter_tags(htmlstr):
  #先过滤CDATA
  re_cdata=re.compile(&#39;//<!\[CDATA\[[^>]*//\]\]>&#39;,re.I) #匹配CDATA
  re_script=re.compile(&#39;<\s*script[^>]*>[^<]*<\s*/\s*script\s*>&#39;,re.I)#Script
  re_style=re.compile(&#39;<\s*style[^>]*>[^<]*<\s*/\s*style\s*>&#39;,re.I)#style
  re_br=re.compile(&#39;<br\s*?/?>&#39;)#处理换行
  re_h=re.compile(&#39;</?\w+[^>]*>&#39;)#HTML标签
  re_comment=re.compile(&#39;<!--[^>]*-->&#39;)#HTML注释
  s=re_cdata.sub(&#39;&#39;,htmlstr)#去掉CDATA
  s=re_script.sub(&#39;&#39;,s) #去掉SCRIPT
  s=re_style.sub(&#39;&#39;,s)#去掉style
  s=re_br.sub(&#39;\n&#39;,s)#将br转换为换行
  s=re_h.sub(&#39;&#39;,s) #去掉HTML 标签
  s=re_comment.sub(&#39;&#39;,s)#去掉HTML注释
  #去掉多余的空行
  blank_line=re.compile(&#39;\n+&#39;)
  s=blank_line.sub(&#39;\n&#39;,s)
  s=replaceCharEntity(s)#替换实体
  return s
##替换常用HTML字符实体.
#使用正常的字符替换HTML中特殊的字符实体.
#你可以添加新的实体字符到CHAR_ENTITIES中,处理更多HTML字符实体.
#@param htmlstr HTML字符串.
def replaceCharEntity(htmlstr):
  CHAR_ENTITIES={&#39;nbsp&#39;:&#39; &#39;,&#39;160&#39;:&#39; &#39;,
        &#39;lt&#39;:&#39;<&#39;,&#39;60&#39;:&#39;<&#39;,
        &#39;gt&#39;:&#39;>&#39;,&#39;62&#39;:&#39;>&#39;,
        &#39;amp&#39;:&#39;&&#39;,&#39;38&#39;:&#39;&&#39;,
        &#39;quot&#39;:&#39;"&#39;,&#39;34&#39;:&#39;"&#39;,}
   
  re_charEntity=re.compile(r&#39;?(?P<name>\w+);&#39;)
  sz=re_charEntity.search(htmlstr)
  while sz:
    entity=sz.group()#entity全称，如>
    key=sz.group(&#39;name&#39;)#去除&;后entity,如>为gt
    try:
      htmlstr=re_charEntity.sub(CHAR_ENTITIES[key],htmlstr,1)
      sz=re_charEntity.search(htmlstr)
    except KeyError:
      #以空串代替
      htmlstr=re_charEntity.sub(&#39;&#39;,htmlstr,1)
      sz=re_charEntity.search(htmlstr)
  return htmlstr
def repalce(s,re_exp,repl_string):
  return re_exp.sub(repl_string,s)
if name==&#39;main&#39;:
  s=file(&#39;169it.com_index.htm&#39;).read()
  news=filter_tags(s)
  print news

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