Replace NA across multiple columns

KNIME Analytics Platform
1

Hello,

I have multiple columns with “NA” and want to replace all of them with “none”. How would I do this? I tried the string manipulation (multi column) node but it did not work, it changed every cell in selected columns to none. I’ve tried the string replacer too but I have around 12 columns and I would need to do this for each column individually.

Thank you

2

Hi @Subha_D try to use the “autotype cast” node by setting the “missing field value pattern” to NA then, after that, use the missing values node ​​to replace with the word none

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3

Hello @Subha_D,

String Manipulation (Multi Column) should work with replace() function. How did you configure it?

Br,
Ivan

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4

Thanks @natanaeldgsantos it works!

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5

Hi @ipazin I selected the columns i wanted to edit then used : replace(“NA”,“NA” ,“None” ). Not sure if this right though…

6

Hello @Subha_D,

first argument is string/column(s) in which you would like to make replacement. In order to do it for multiple columns you should use currentColumn placeholder and include wanted columns. Something like this:

replace($$CURRENTCOLUMN$$,"Na","None")

Br,
Ivan

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7

Thank you! It works now

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8

Glad to hear that!
Ivan

9

I once saw a solution from @ipazin in the forum where he unpivoted the data, did the replace and pivoted again. That should also work

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10

Hello,

here is workflow example on approach @Daniel_Weikert is talking about.

That seems to me way to go when in need to apply same expression/operation on multiple columns and can’t use String Manipulation/Math Formula (Multi Column) nodes.

Br,
Ivan

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