不区分大小写的正则表达式没有re.compile?

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'

你也可以在模式编译时定义不区分大小写:

pattern = re.compile('FIle:/+(.*)', re.IGNORECASE)

#'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']

进口

import re

在运行时处理中:

RE_TEST = r'test'
if re.match(RE_TEST, 'TeSt', re.IGNORECASE):

应该提到的是，不使用re.compile是浪费的。每次调用上述匹配方法时，正则表达式都将被编译。这在其他编程语言中也是错误的做法。下面是更好的实践。

在应用程序初始化中:

self.RE_TEST = re.compile('test', re.IGNORECASE)

在运行时处理中:

if self.RE_TEST.match('TeSt'):

要执行不区分大小写的操作，请提供re.IGNORECASE

>>> import re
>>> test = 'UPPER TEXT, lower text, Mixed Text'
>>> re.findall('text', test, flags=re.IGNORECASE)
['TEXT', 'text', 'Text']

如果我们想替换匹配大小写的文本…

>>> def matchcase(word):
def replace(m):
text = m.group()
if text.isupper():
return word.upper()
elif text.islower():
return word.lower()
elif text[0].isupper():
return word.capitalize()
else:
return word
return replace


>>> re.sub('text', matchcase('word'), test, flags=re.IGNORECASE)
'UPPER WORD, lower word, Mixed Word'

如果你想替换但仍然保持前str的风格，这是可能的。

例如:突出显示字符串“test asdasd test asd test asdasd”。

sentence = "test asdasd TEST asd tEst asdasd"
result = re.sub(
'(test)',
r'<b>\1</b>',  # \1 here indicates first matching group.
sentence,
flags=re.IGNORECASE)

测验 asdasd 测试 asd 测试 asdasd

1. < p > flags=re.IGNORECASE

   Regx3GList = re.search("(WCDMA:)((\d*)(,?))*", txt, re.IGNORECASE)
   

2. 不区分大小写的标记(?i)

   Regx3GList = re.search("**(?i)**(WCDMA:)((\d*)(,?))*", txt)