CODEWITHSUNDEEP
rregex
Rafael
Rafael

Reputation: 3196

regex match match numbers or number around colon but not after certain string

For example I want to match numbers around : but not if they fall within a parentheses. 

str_extract( "2010:2012,mean(2010:2015)", '[0-9:0-9]+')
## 2010:2012 correct

str_extract( "mean(2010:2015),2010:2012", '[0-9:0-9]+')
## 2010:2015 incorrect

How can I check if there parentheses?

Upvotes: 1

Views: 845

Answers (1)

anubhava
anubhava

Reputation: 785631

First of all [0-9:0-9]+ is not correct. As it matches 1 or more of a digit or colon. So it will match 123 or just : also.

Correction regex would be:

[0-9]+:[0-9]+

Now if you want to avoid string inside parentheses then use a negative lookahead (assuming all the parentheses are balanced and unescaped):

[0-9]+:[0-9]+(?![^()]*\))

(?![^()]*\)) is a negative lookahead based condition that would fail the match is number:number is followed by a ) without matching a ( and ).

Note in r you will have use double escape it:

'[0-9]+:[0-9]+(?![^()]*\\))'

RegEx Demo

Upvotes: 2

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