Order not maintained in nesting columns

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dataiku_user
Level 2
Order not maintained in nesting columns

I have several columns that I am combining using data preparation recipe - and the 'nest' functionality. A number of these columns are in pairs and I am nesting them into a third column.



E.g: a1,b1 nested (in that order) to a1_b1, a2,b2 nested to a2_b2 and so on. Thus the map object created should be a1 and then b1.

However, an issue I face is for certain column pairs, the ordering is not maintained. i.e. when nested, the b column comes before a though the selection is first a and then b. The issue seems to affect in a random fashion.



Inputs;




a b
1 2


Outputs:




{"b": 2, "a": 1}


Is this a bug or am I missing something?

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1 Solution
Alex_Combessie
Dataiker Alumni
Hello,

When using the "Nest columns" processor in a visual Prepare recipe, DSS converts the columns to a key:value format. By design, this format is not ordered by key. If you want to preserve order, I would advise using a "Concatenate" processor.

Note that for advanced processing needs, the visual Prepare recipe supports a formula language close to Excel, and base Python.

Cheers,

Alex

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2 Replies
Alex_Combessie
Dataiker Alumni
Hello,

When using the "Nest columns" processor in a visual Prepare recipe, DSS converts the columns to a key:value format. By design, this format is not ordered by key. If you want to preserve order, I would advise using a "Concatenate" processor.

Note that for advanced processing needs, the visual Prepare recipe supports a formula language close to Excel, and base Python.

Cheers,

Alex
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dataiku_user
Level 2
Author
Ok, thanks for a prompt answer. I figured out that backslash works for escape in the formula recipe
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