How can we limit the regex for first found?

KNIME Analytics Platform
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I am extracting the substring from a string using Regex extractor node but the string has multiple substrings that match to that regex. but I need to extract the first found string?

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@qqilihq can you please help me with this?

3

I am not sure if non greedy also works in KNIME (sorry can’t test myself right now), but you could try your pattern with a “?”
e.g.
(.*?)
you would replace the dot star with your pattern.

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Hi PankajChaudhary,

Could you post an example of your input and what you’re actually expecting?

–Philipp

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@qqilihq
String: ABW-89^Description^Code^scfs
regex: (?<=^)(.*?)(?=^)
output: Description Code
I need only the first substring match with regex from the string.
Expected Output: Description

6

For the given example, you literally want “Description”? Then try this: [^\^]*\^([^\^]*)\^.*

  • [^\^]*\^ : read all characters until a ^ is encountered,
  • ([^\^]*): then capture characters which are not ^,
  • \^.*: from there match rest of string

Or do you want “ABW-89”? then simply use ([^\^]*)\^.*

–Philipp

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7

Not sure whether my idea would fit to your requirements. But what about using a Cell Splitter Node Cell Splitter — NodePit with “^” as delimiter?
This node splits the input string in different columns: In your example you get 4 columns with one string each

ABW-89 | Description | Code | scfs

Unfortunately the node is deprecated.

3 Likes
8

Thanks, @qqilihq your suggestion helped me to solve my problem.
Thank you so much.

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