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

							            

					

            
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：
 
  
 
   
 
    
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
 
  
 
   
 
    
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,
 
  
 
   
 
    
regular_v2 = re.findall(r "^https" , “https://docs.python.org/3/whatsnew/3.6.html” )
print (regular_v2)
# [‘https’]
 
   
 
  
 
  
 
  
　　
 
  
用$符号表示以html结尾的字符串返回,判断是否字符串结束的字符串</pre><divclass="cnblog{s}_{H}ighlightersh-gutter"><div><divclass="syntaxhighlighterpython"><divclass="table-box"><tablecellspacing="0"cellpadding="0"border="0"><tbody><tr><tdclass="gutter"><divclass="linenumber1index0alt2">1</div><divclass="linenumber2index1alt1">2</div><divclass="linenumber3index2alt2">3</div></td><tdclass="code"><div><divclass="linenumber1index0alt2"><codeclass="pythonplain">regula{r}_{v}3</code><codeclass="pythonkeyword">=</code><codeclass="pythonplain">re.findall(r</code><codeclass="pythonstring">"html$",“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
   
   
   
   

    
    
    
    

     
     
     
     
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
   
   
   
   

    
    
    
    

     
     
     
     
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
   
   
   
   

    
    
    
    

     
     
     
     
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
   
   
   
   

    
    
    
    

     
     
     
     
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
   
   
   
   

    
    
    
    

     
     
     
     

      
      
      
      

       
       
       
       

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