This looks really nice! I currently use LiveCode (which isn't Python-based) for my daily "I have a bunch of data I'm looking to filter/transform/clean up" tasks. I'm always on the lookout for a similar tool, which for me means:
1. Text inputs (table/spreadsheet inputs?)
2. Text outputs
3. Buttons
4. Menus
5. Sliders
6. Checkboxes/radio buttons
And bonus points for:
7. bundle it up and give it to someone else to run
Any chance you'll push further into the build-a-UI-to-muck-with-data realm?