You can run libraries like Pandas in WebAssembly in Pyodide - in fact Pandas works already. Here's a demo I built with it a while ago: https://tools.simonwillison.net/pyodide-bar-chart

It's not too hard to compile a C extension for Python to a WebAssembly and bundle that in a .so file in a wheel. I did an experiment with that the other day: https://github.com/simonw/tiny-haversine?tab=readme-ov-file#...