CODEWITHSUNDEEP
regex
user2765278
user2765278

Reputation:

Matching numbers inside nested numbered groups

I am trying to find and capture all numbers inside ( and ) separately in my data, ignoring the rest of the numbers.

My data looks like this

21 [42] (12) 19 25 [44] (25 26 27) 17 (14 3) 8 1 6 (19)

So I want to find matches for 12, 25, 26, 27, 14, 3 and 19

I tried doing \((\d+)\)* but this only gives me 12, 25, 14, 19

Any help is appreciated.

Upvotes: 0

Views: 63

Answers (3)

Alan Moore
Alan Moore

Reputation: 75222

I don't see any nesting there. Nesting implies something like this: 

12 (34 (56) 78) 90

If you really have data like that--especially if you don't know how deep the nesting can go--I would advise you not to use regexes. But your problem looks very simple; this should be all you need:

\d+(?=[^()]*\))

As with the other answers, the lookahead asserts that there's closing bracket up ahead, with no opening brackets between here and there. I excluded closing brackets too, mostly for the sake of efficiency. Otherwise it would tend to zoom on past the ) at first, only to have to backtrack to it.

Upvotes: 0

alpha bravo
alpha bravo

Reputation: 7948

use this pattern \d+(?=(((?!\().)*)\)) example here

modified to the following (\d+)(?=(?:(?!\().)*\)) demo

Upvotes: 0

hwnd
hwnd

Reputation: 70722

You can combine a positive lookahead with a negative lookahead to get your desired results.

(\d+)(?=(?:.(?!\())*\))

Regular expression:

(           group and capture to \1:
 \d+        digits (0-9) (1 or more times)
)           end of \1
(?=         look ahead to see if there is:
 (?:        group, but do not capture (0 or more times)
   .        any character except \n
   (?!      look ahead to see if there is not:
    \(      '('
   )        end of look-ahead
)*          end of grouping
 \)         ')'
)           end of look-ahead

See a demo

Upvotes: 1

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