Removing a row if contains a value within a list

I’ve used the Groupby node to aggregate all the different types of transport in a city all into a column containing 1 list.

Now I’m hoping to remove any rows that have the value “Car” in the list. I’ve been trying to do this through Rule-Based row filter, but with no luck so far.

Would appreciate any help!


Welcome to the world of KNIME.

The first idea coming to my mind:
Delete “Car” from the second list and make a join with your first list.

1 Like

Hi @nightsky3, and welcome to the forum!

As @knimediger has said, you could find a way of filtering the list first, but you would need to find all cities for which a vehicle type is car, and then do an “anti-join” using that list of cities to remove all rows for cities where at least one row is “Car”.

But actually, you can also just use a Row filter either using Regex

or by specifying “based on collection elements”:

The attached workflow gives an example of all the above mechanisms. There will be other ways to achieve this result I’m sure.

Filter aggregations.knwf (17.0 KB)


I’d have used “Unique concatenate” in the GroupBy and then a Row Filter, but that’s because I didn’t know that the filter works on lists. Now I know what that checkbox is for! :slight_smile:


@nightsky3, @takbb, @knimediger, @Thyme
I figured out one more solution with Groupby, Ungroup and Reference Row Filter nodes:

Please find attached the workflow!

Best Regards,

Filter_out_cities(cars).knar.knwf (24.6 KB)


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