Following regex matches both 59-59-59 and 59-59-59-59 and outputs only 59
The intent is to match four and only numbers followed by - with the max number being 59. Numbers less than 10 are represented as 00-09.
print(re.match(r'(\b[0-5][0-9]-{1,4}\b)','59-59-59').groups())
--> output ('59-',)
I need a pattern match that matches exactly 59-59-59-59
and does not match 59--59-59or 59-59-59-59-59
Try using the following pattern, if using re.match:
[0-5][0-9](?:-[0-5][0-9]){3}$
This is phrased to match an initial number starting with 0 through 5, followed by any second digit. Then, this is followed by a dash and a number with the same rules, this quantity three times exactly. Note that re.match anchor at the beginning by default, so we only need an ending anchor $.
Code:
print(re.match(r'([0-5][0-9](?:-[0-5][0-9]){3})$', '59-59-59-59').groups())
('59-59-59-59',)
If you intend to actually match the same number four times in a row, then see the answer by @Thefourthbird.
If you want to find such a string in a larger text, then consider using re.search. In that case, use this pattern:
(?:^|(?<=\s))[0-5][0-9](?:-[0-5][0-9]){3}(?=\s|$)
Note that instead of using word boundaries \b I used lookarounds to enforce the end of the "word" here. This means that the above pattern will not match something like 59-59-59-59-59.
59-59-59-59 in the string 59-59-59-59-59
print(re.match(r'(\b(?:-[0-5][0-9]){4}\b)', '59-59-59-57').groups()) not work?
In your pattern, this part -{1,4} matches 1-4 times a hyphen so 59-- will match.
If all the matches should be the same as 59, you could use a backreference to the first capturing group and repeat that 3 times with a prepended hyphen.
\b([0-5][0-9])(?:-\1){3}\b
Your code might look like:
import re
res = re.match(r'\b([0-5][0-9])(?:-\1){3}\b', '59-59-59-59')
if res:
print(res.group())
If there should not be partial matches, you could use an anchors to assert the ^ start and the end $ of the string:
^([0-5][0-9])(?:-\1){3}$
59-59-59-59 in the string 59-59-59-59-59
If there should not be partial matches, you could use an anchors to assert the ^ start and the end $ of the string.print(re.match(r'(\b([0-5][0-9])(?:-\1){3}\b)', '59-59-59-59').groups()) fails -> raise error, v # invalid expression sre_constants.error: cannot refer to open group
^[0-5][0-9](?:-[0-5][0-9]){3}$--separated numbers, usere.match(r'[0-5][0-9](?:-[0-5][0-9]){3}$', s). If there can be 1 to 4 of the numbers replace{3}with{0,3}. If you need to get the numbers after validation, uses.split('-')after the string validation passes.