python 中正则表达式用法 re.findall()

参考博客原址：https://blog.csdn.net/YZXnuaa/article/details/79346963

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            <pre>正则 re.findall  的简单用法（返回string中所有与pattern相匹配的全部字串，返回形式为数组）

语法：

1	findall(pattern, string, flags = 0 )

import re

Python 正则表达式 re findall 方法能够以列表的形式返回能匹配的子串

print (help(re.findall))

print (dir(re.findall))

findall查找全部r标识代表后面是正则的语句

1 2 3

regular_v1 = re.findall(r "docs" , “https://docs.python.org/3/whatsnew/3.6.html” ) print (regular_v1) # [‘docs’]

符号^表示匹配以https开头的的字符串返回,

1 2 3

regular_v2 = re.findall(r "^https" , “https://docs.python.org/3/whatsnew/3.6.html” ) print (regular_v2) # [‘https’]

　　

用
     
     $符号表示以html结尾的字符串返回,判断是否字符串结束的字符串</pre><div class="cnblogs_Highlighter sh-gutter"><div><div class="syntaxhighlighter python"><div class="table-box"><table cellspacing="0" cellpadding="0" border="0"><tbody><tr><td class="gutter"><div class="line number1 index0 alt2">1</div><div class="line number2 index1 alt1">2</div><div class="line number3 index2 alt2">3</div></td><td class="code"><div><div class="line number1 index0 alt2"><code class="python plain">regular_v3 </code><code class="python keyword">=</code> <code class="python plain">re.findall(r</code><code class="python string">"html$",“https://docs.python.org/3/whatsnew/3.6.html”)
  
  

   
   print 
   
   (regular_v3)
  
  
  
  

   
   # [‘html’]
  
  
# […]匹配括号中的其中一个字符
  
  

   
   

    
    

     
     

      
      

       
       
 
        
 
         
 
          

            1 
          
 
          

            2 
          
 
          

            3 
          
 
         
 
          
 
           
 
            regular_v4  
            = 
            re.findall(r 
            "[t,w]h" 
            , 
            “https://docs.python.org/3/whatsnew/3.6.html” 
            ) 
           
 
           
 
            print 
            (regular_v4) 
           
 
           
 
            # [‘th’, ‘wh’] 
           
 
          
 
        
 
       
      
      
     
     
    
    
   
   
  
  
“d”是正则语法规则用来匹配0到9之间的数返回列表
  
  

   
   

    
    

     
     

      
      

       
       
 
        
 
         
 
          

            1 
          
 
          

            2 
          
 
          

            3 
          
 
          

            4 
          
 
          

            5 
          
 
          

            6 
          
 
         
 
          
 
           
 
            regular_v5  
            = 
            re.findall(r 
            "\d" 
            , 
            “https://docs.python.org/3/whatsnew/3.6.html” 
            ) 
           
 
           
 
            regular_v6  
            = 
            re.findall(r 
            "\d\d\d" 
            , 
            “https://docs.python.org/3/whatsnew/3.6.html/1234” 
            ) 
           
 
           
 
            print 
            (regular_v5) 
           
 
           
 
            # [‘3’, ‘3’, ‘6’] 
           
 
           
 
            print 
            (regular_v6) 
           
 
           
 
            # [‘123’] 
           
 
          
 
        
 
       
      
      
     
     
    
    
   
   
  
  
小d表示取数字0-9，大D表示不要数字，也就是出了数字以外的内容返回
  
  

   
   

    
    

     
     

      
      

       
       
 
        
 
         
 
          

            1 
          
 
          

            2 
          
 
          

            3 
          
 
         
 
          
 
           
 
            regular_v7  
            = 
            re.findall(r 
            "\D" 
            , 
            “https://docs.python.org/3/whatsnew/3.6.html” 
            ) 
           
 
           
 
            print 
            (regular_v7) 
           
 
           
 
            # [‘h’, ‘t’, ‘t’, ‘p’, ‘s’, ‘:’, ‘/’, ‘/’, ‘d’, ‘o’, ‘c’, ‘s’, ‘.’, ‘p’, ‘y’, ‘t’, ‘h’, ‘o’, ‘n’, ‘.’, ‘o’, ‘r’, ‘g’, ‘/’, ‘/’, ‘w’, ‘h’, ‘a’, ‘t’, ‘s’, ‘n’, ‘e’, ‘w’, ‘/’, ‘.’, ‘.’, ‘h’, ‘t’, ‘m’, ‘l’] 
           
 
          
 
        
 
       
      
      
     
     
    
    
   
   
  
  
“w”在正则里面代表匹配从小写a到z,大写A到Z，数字0到9
  
  

   
   

    
    

     
     

      
      

       
       
 
        
 
         
 
          

            1 
          
 
          

            2 
          
 
          

            3 
          
 
         
 
          
 
           
 
            regular_v8  
            = 
            re.findall(r 
            "\w" 
            , 
            “https://docs.python.org/3/whatsnew/3.6.html” 
            ) 
           
 
           
 
            print 
            (regular_v8) 
           
 
           
 
            #[‘h’, ‘t’, ‘t’, ‘p’, ‘s’, ‘d’, ‘o’, ‘c’, ‘s’, ‘p’, ‘y’, ‘t’, ‘h’, ‘o’, ‘n’, ‘o’, ‘r’, ‘g’, ‘3’, ‘w’, ‘h’, ‘a’, ‘t’, ‘s’, ‘n’, ‘e’, ‘w’, ‘3’, ‘6’, ‘h’, ‘t’, ‘m’, ‘l’] 
           
 
          
 
        
 
       
      
      
     
     
    
    
   
   
  
  


“W”在正则里面代表匹配除了字母与数字以外的特殊符号
  
  

   
   

    
    

     
     

      
      

       
       

         1 
       
       
       

         2 
       
       
       

         3 
       
      
      

       
       
 
        
 
         regular_v9  
         = 
         re.findall(r 
         "\W" 
         , 
         “https://docs.python.org/3/whatsnew/3.6.html” 
         ) 
        
 
        
 
         print 
         (regular_v9) 
        
 
        
 
         # [’:’, ‘/’, ‘/’, ‘.’, ‘.’, ‘/’, ‘/’, ‘/’, ‘.’, ‘.’] 
        
 
       
     
     
    
    
   
   
  
  
            

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            <pre>正则 re.findall  的简单用法（返回string中所有与pattern相匹配的全部字串，返回形式为数组）