SuperTool is a free Gramps addon from the Isotammi group. (A workgroup of Finland’s genealogical society.) It simplifies touching Gramps tree data directly with Python scripts. (When you Execute a script in SuperTool, it looks at what Category is active in the View. Then does all the niggling Python Initialization details to make that data easily accessible… down to the point of knowing which records are selected in the filtered view.)
There was a discussion thread just a week ago where the task was to update a couple thousand Source’s titles and abbreviations.
The user obviously had some programming background. But they discovered SuperTool and had a script that let them complete the task the following day.
In the final message, @Bigfoot shared a script that loaded a CSV file (with field name headers for source ID, title, abbrev), then parsed the CSV and overwrote that data in the Source view. Other than needing to paste in the path with filename for the CSV, the script is ready to run.
He did some parts in a somewhat unsafe way. (But that might just be my impression.) Instead of using the sandboxed virtual copy of the records that SuperTool offers for testing before committing, he worked directly on live data. Look at the SuperTool Help for lists of what all the fieldnames are in each view.
Also, please tell us if you are using the just released 5.2 version of Gramps. Both the CSV import and SuperTool have new 5.2 features.