下面这个错误是由于在正则[...]的内部,减号'-'是一个有特殊含义的字符(代表字符范围)

所以如果需要在[...]内匹配减号'-',需要用反斜杠'\'转义.

 

>>> import re>>> re.split(r'[+\-*/%]','+a-b-c')['', 'a', 'b', 'c'] >>> re.split(r'[+-*/%]','+a-b-c')Traceback (most recent call last):  File "
     
      ", line 1, in 
      
           re.split(r'[+-*/%]','+a-b-c')  File "C:\Python27\lib\re.py", line 167, in split    return _compile(pattern, flags).split(string, maxsplit)  File "C:\Python27\lib\re.py", line 242, in _compile    raise error, v # invalid expressionerror: bad character range