regex last repetition

Question

I have a string: 0220110000AL0091 and I would like to get back the last 000 for replace by three spaces. So for: 0220110000AL0091, I want to replace by 0220110 AL0091.

I don't know how to apply the regex between the 7th and 11th characters!

Thanks

What language are you working with? Assuming you mean general repetition, not necessarily three zeros, try `/(.)\1\1(?!\1)/` and replace it with three spaces. — Sebastian Simon, Mar 14 '18 at 14:12
By matching 6 arbitrary characters before, and then necessary amount zeroes/digits after that …? — CBroe, Mar 14 '18 at 14:12

Right leg · Answer 1 · 2018-03-14T14:17:21.347

1

You're looking for a negative lookahead. You will look for a sequence of three zeros, not followed by a zero.

Here is how you could do it in Python (doc here, ctrl+f -> (?!):

>>> import re
>>> s = "0220110000AL0091"
>>> re.sub("000(?!0)", "   ", s)
'0220110   AL0091'
>>>

edited Mar 14 '18 at 14:17

answered Mar 14 '18 at 14:15

Right leg

16,080
7
48
81

Thanks, it's perfect ! – user2998243 Mar 14 '18 at 14:16
1

@Rightleg how did you know OP is using python? – ctwheels Mar 14 '18 at 14:38
@ctwheels I don't, it's just an example with a common language that I know. Besides, as long as the language supports lookahead assumptions, this regex is likely to work, and if it didn't, I think the negative lookahead would still be the solution. – Right leg Mar 14 '18 at 14:41

regex last repetition

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