String Manipulator Multi-Column and Lists

HI,
I have trouble converting columns that contain lists to a string. I was able to do so in the single-column String Manipulator node (basically by calling join on the cell) but these columns don’t show up in the Multi-Column Node.

Hello @timosachsenberg,

welcome to KNIME Community!

You are right. List/Collection column type is not present in Include/Exclude dialog. Have created ticket to address it. (Internal reference: AP-15218)

As a workaround you can use loop to loop over every list column which needs to be converted to string but wondering why do you have a List column that you want to join as such and convert? Maybe there is a better approach to take :thinking:

Br,
Ivan

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The list column is the result of parsing an external file with our MzTabReader node. In some cases, we want to preserve the lists of strings, doubles, integers, in some cases we just want to merge them into a single string.

Hello @timosachsenberg,

I see. Then as suggested above use Column List Loop Start node and include List columns which values you want to merge into one single string. Here is example workflow to check:

Br,
Ivan

1 Like