Anaconda Code is what you're looking for! It's Python (via PyScript) running as an Excel plug-in, that has full access to the spreadsheet and can harness a big part of the core PyData stack (including matplotlib, sklearn, pandas, etc.)

The whole thing runs via PyScript/WASM, and lives locally inside the Excel spreadsheet. https://www.anaconda.com/blog/introducing-anaconda-code-add-...