Rule-based row filter - Remove non numbers


I am new to KNIME and I am sorry if this questions has been posted before, or if it is too simple…
I am trying to remove the rows which don’t contain a number in one of my columns (2nd). I guess I could do this with the Rule-based Row Filter, but I am stuck at figuring out what expression to use…

Thank you very much in advance for your help!

Hi @CK24_SH

Can you give more context?

What is the column type of this column?
Are the cells you want to evaluate empty? If not, what do they contain?

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Hi @elsamuel

This is how my data looks like. I want to delete the rows that don’t contain numbers in Column B. It is a normal text string…

Please let me know if you need some more screenshots or anything else.

Thank you


Hi CK24_SH, as usual there are several ways to do it. They I would, would be by adding a “Rule-based Row Filter” with a rule combining a little bit of Regex like:

$Name of the Column$ MATCHES “.([0-9]{8}).” => FALSE

This way, as far as I can see numbers set have a character of 8. Hope this helps.



Use String to number node and then row filter to filter the missing values (values which could not be converted to number).


In that case you’ll delete the leading zero of the numbers, so I think @JorgeAraya20CR solution would fit better.

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True. if that is an issue, copy the column before hand and perform string to number and filtering in the copy.