re.split测试

Definition: re.split(pattern, string, maxsplit=0, flags=0)
如下将字符串按空格分开，maxsplit是分离的次数，maxsplit=1分离一次，默认为0，不限制次数

In [67]: text
Out[67]: 'HTTP/1.1 301 Moved Permanently'


In [68]: re.split(r"\s+",text)
Out[68]: ['HTTP/1.1', '301', 'Moved', 'Permanently']


In [69]: re.split(r"\s+",text,0)
Out[69]: ['HTTP/1.1', '301', 'Moved', 'Permanently']


In [70]: re.split(r"\s+",text,1)
Out[70]: ['HTTP/1.1', '301 Moved Permanently']


In [71]: re.split(r"\s+",text,2)
Out[71]: ['HTTP/1.1', '301', 'Moved Permanently']


In [72]: re.split(r"\s+",text,3)
Out[72]: ['HTTP/1.1', '301', 'Moved', 'Permanently']


In [73]: re.split(r"\s+",text,-1)
Out[73]: ['HTTP/1.1 301 Moved Permanently']

如果用括号将正则表达式括起来，那么匹配的字符串也会被列入到list中返回；如果用非捕获分组与非分组结果一致。

In [75]: re.split('\W+', 'Words, words, words.')
Out[75]: ['Words', 'words', 'words', '']

In [76]: re.split('(\W+)', 'Words, words, words.')
Out[76]: ['Words', ', ', 'words', ', ', 'words', '.', '']

In [77]: re.split('\W+', 'Words, words, words.', 1)
Out[77]: ['Words', 'words, words.']
In [12]: re.split('((?:)\W+)', 'Words, words, words.')
Out[12]: ['Words', 'words', 'words', '']
 

如果在字符串的开始或结尾就匹配，返回的list将会以空串开始或结尾。

In [78]: re.split('(\W+)', '...words, words...')
Out[78]: ['', '...', 'words', ', ', 'words', '...', '']

如果字符串不能匹配，将会返回整个字符串的list。

In [83]: re.split("c","python is better")
Out[83]: ['python is better']