Alright matplotlib afficionados, we know how to plot a donut chart, but what is better than a donut chart? A double-donut chart. Specifically: We have a set of elements that fall into disjoint categories and sub-categories of the first categorization. The donut chart should have slices for the categories in the outer ring and slices for the sub-categories in the inner ring, obviously aligned with the outer slices.
Is there any library that provides this or do we need to work this out here?
