Replace empty value based on condition on another row

[magic_mike]

Hi everyone, 

I'm trying to fill empty cells on a database based on the value on another row but I am struggling a bit on this. 

Basically I have a time based table where I have empty cells on some days. I would like to fill those cells with the value of the previous day when they happen to be  empty (example below).

Input:

Date	Value
2020-01-01	1
2020-01-02	2
2020-01-03
2020-01-04	3

Output:

Date	Value
2020-01-01	1
2020-01-02	2
2020-01-03	2
2020-01-04	3

I know in Excel a simple if + vlookup would do the trick but I can't find a solution on Dataiku...

As my project will be used by "non-coder" colleagues, I'd like to avoid the Python function method and stick to a visual recipe.

Thank you! 

[tgb417 · Accepted solution]

@magic_mike 

Welcome to the Dataiku community. 

In the visual prepare recipes there is a step called fill down.  Here is the documentation 

https://doc.dataiku.com/dss/latest/preparation/processors/up-down-fill.html

It looks like you might be doing some time series work.  You may find the time series plugin to be of some help as well.   

https://www.dataiku.com/product/plugins/timeseries-preparation/

let us all know how you are getting on with your project.

[magic_mike]

Thank you for your answer Tom! 

I didn't think about the time series plugin. It will be helpful for the project! 

[tgb417]

@magic_mike ,

If time series is your challenge, this Dataiku academy course might be just what you need for a detailed description on its use.

https://academy.dataiku.com/path/ml-practitioner/time-series-preparation-1