Dash DataTable - is 'derived_virtual_data' a read-only property?

General Question:
When using the Dash DataTable derived_virtual_data property as an Output in a callback, will this property value actually get updated (or is it read-only)? or does it get automatically overwritten if there is a filter_query already applied to the existing DataTable?

Short answer – Yes, it’s read only.

Can you say why you want to update it in a callback?

Thanks for the quick reply!

My goal is to automatically “merge” rows when a particular condition is met in the in-view table (see image below).
In the image below, I start with a GroupBy table with Groups defined by the first column. I’d like to “collapse”/“merge” rows within a Group (e.g., ‘apple’) if all the rows in that group contain a single (non-empty) value across all columns.

Also, the GroupBy table shown at the top is also filtered.

Oh, I see. I think the easiest way would be to do the GroupBy in the top table. However, if that’s not possible, you would have to manually filter and sort - as shown in this section of the docs: Python-Driven Filtering, Paging, Sorting | Dash for Python Documentation | Plotly

Thanks for your responses, @AnnMarieW !

The top table already has the GroupBy applied. Just knowing that derived_virtual_data is essentially read-only is very helpful. I’ve pushed the “merge row” operation in a downstream process for now.