I realize I'm talking about C++ not C, but coincidentally just today I ported our 7 year old library's Swig/Python interface to nanobind. What a fragile c9k Swig has been all these years (don't touch it!) and the nanobind transformation is so refreshing and clean, and lots of type information suddenly available to Python programs. One day of effort and our tests all pass, and now nanobind seems able to allow us to improve the ergonomics (from the Python pov) of our lib.