在Python中,我可以使用re.compile将正则表达式编译为不区分大小写:

>>> s = 'TeSt'
>>> casesensitive = re.compile('test')
>>> ignorecase = re.compile('test', re.IGNORECASE)
>>> 
>>> print casesensitive.match(s)
None
>>> print ignorecase.match(s)
<_sre.SRE_Match object at 0x02F0B608>

是否有一种方法可以做同样的事情,但不使用re.compile。我在文档中找不到任何类似Perl的I后缀(例如m/test/ I)的东西。


当前回答

对于不区分大小写的正则表达式: 在代码中添加有两种方法:

旗帜=再保险。IGNORECASE Regx3GList = re.search(“(WCDMA) ((\ d *)(,?))*", txt re.IGNORECASE) 不区分大小写的标记(?i) Regx3GList = re.search(“* *(?我)* * (WCDMA:) ((\ d *)(,?))*", txt)

其他回答

将re.IGNORECASE传递给search、match或sub的flags参数:

re.search('test', 'TeSt', re.IGNORECASE)
re.match('test', 'TeSt', re.IGNORECASE)
re.sub('test', 'xxxx', 'Testing', flags=re.IGNORECASE)

你也可以使用不带IGNORECASE标志的搜索/匹配执行不区分大小写的搜索(在Python 2.7.3中测试):

re.search(r'(?i)test', 'TeSt').group()    ## returns 'TeSt'
re.match(r'(?i)test', 'TeSt').group()     ## returns 'TeSt'
#'re.IGNORECASE' for case insensitive results short form re.I
#'re.match' returns the first match located from the start of the string. 
#'re.search' returns location of the where the match is found 
#'re.compile' creates a regex object that can be used for multiple matches

 >>> s = r'TeSt'   
 >>> print (re.match(s, r'test123', re.I))
 <_sre.SRE_Match object; span=(0, 4), match='test'>
 # OR
 >>> pattern = re.compile(s, re.I)
 >>> print(pattern.match(r'test123'))
 <_sre.SRE_Match object; span=(0, 4), match='test'>

不区分大小写的标记(?i)可以直接合并到正则表达式模式中:

>>> import re
>>> s = 'This is one Test, another TEST, and another test.'
>>> re.findall('(?i)test', s)
['Test', 'TEST', 'test']

(?i)用以下有效标志匹配模式的剩余部分:不区分大小写匹配(忽略[a-zA-Z]的大小写)

>>> import pandas as pd
>>> s = pd.DataFrame({ 'a': ["TeSt"] })
>>> r = s.replace(to_replace=r'(?i)test', value=r'TEST', regex=True)
>>> print(r)
      a
0  TEST