我想确定一个字符串S是否有一个子串MYSUBSTRING,前面是我需要确定的两个连续数字。
例如:
'aaa79bbbMYSUBSTRINGccc' ==>我想要7,9和True(或7,9和MYSUBSTRING)
'aaa79bbbccc' ==>我想要7,9和False(或7,9和无)
我可以使用SINGLE正则表达式吗?如果是这样,哪一个?
答案 0 :(得分:4)
以下正则表达式应该这样做:
(\d)(\d)(?:.*?(MYSUBSTRING))?
>>> re.search(r'(\d)(\d)(?:.*?(MYSUBSTRING))?', 'aaa79bbbMYSUBSTRINGccc').groups()
('7', '9', 'MYSUBSTRING')
>>> re.search(r'(\d)(\d)(?:.*?(MYSUBSTRING))?', 'aaa79bbbccc').groups()
('7', '9', None)
答案 1 :(得分:0)
当然,您可以使用(\d)(\d).*?(MYSUBSTRING)?
。在Python中,您可以在re.search
函数中使用它,如下所示:
s = ... # your string
m = re.search(r'(\d)(\d).*?(MYSUBSTRING)?', s)
m.group(1) # first digit
m.group(2) # second digit
m.group(3) # the substring, or None if it didn't match
答案 2 :(得分:0)
一个有趣的问题。这种怪异:
(\d)(\d)(.(?!(MYSUBSTRING)))*.?(MYSUBSTRING)?
似乎适合我。
细分:
(\d)(\d) # capture 2 digits
(.(?!(MYSUBSTRING)))* # any characters not preceded by MYSUBSTRING
.? # the character immediately before MYSUBSTRINg
(MYSUBSTRING)? # MYSUBSTRING, if it exists