Not the only route, and a Python rewrite would not be accepted as the proof. Lean sits with Coq, Isabelle, and Agda: languages built around a small checker you can actually trust. Python can run the same steps and even print a certificate, but that certificate only counts once a trusted checker reads it. A script that exits clean is a calculation. A proof term that type-checks is what gets taken as the theorem. That gap is the whole argument.