In a Jupyter Notebook with SageMath kernel I'd like to offer the user an interactive for selecting a country by first selecting a region and then a country, from a dropdown list of countries in that region.
Ideally both selections would occur in one cell and the options for the second selector adapt as soon as the first selection is made. Alternatively I may have both selectors in different cells, but then the second cell should be executed whenever the variable selected in the first cell changes.
Would that be possible?
