Dear Andreia Saavedra Cardoso

You can perform simple as well as advanced calculations on all or selected records. However, these links might be useful further, have a look:

1. https://pro.arcgis.com/en/pro-app/latest/tool-reference/data-management/calculate-field-examples.htm

2. https://desktop.arcgis.com/en/arcmap/latest/manage-data/tables/calculate-field-examples.htm

3. https://towardsdatascience.com/filtering-data-frames-in-pandas-b570b1f834b9

4. https://pandas.pydata.org/docs/getting_started/intro_tutorials/05_add_columns.html

5. https://github.com/scikit-hep/awkward-0.x

6. https://github.com/8080labs/ppscore

7. https://github.com/datacamp/courses-introduction-to-python/blob/master/chapter4.md

8. https://github.com/datacamp/courses-introduction-to-python/blob/master/chapter1.md

Kind Regards

Qamar Ul Islam

Thank you, Qamar Ul Islam. I am doing the python course at Datacamp, with Hugo Bowne-Anderson, but I am still in the initial module, learning the basics, so I don't have access to more complex functions.

What I really need to do seems to be possible with the function indicated by Nasir Hameed SelectRandomByPercent, which I'm still going to try but it seems to do what I need. Thank you also for all the useful material in the links you provided.

Kind regards,

The function SelectRandomByPercent works perfectly.

For my question, although, there were slight adaptations since I wanted a randomly subset X% records of a previous selection, that is, removing a % of selected records from the pre-selection. It works with raster layers as well.

For that purpose, I recommend this exchange: https://newbedev.com/how-to-randomly-subset-x-of-selected-points

Thank you, Nasir Hameed.

Kind regards,