Runtime Python Virtual Environment Switching based on Cantor
A long‑running backend that evaluates Python code must solve one problem well: switching the active interpreter or virtual environment at runtime without restarting the host process. A reliable solution depends on five pillars: unambiguous input semantics, reproducible version discovery, version‑aware initialization, disciplined management of process environment and sys.path, and transactional switching that can roll back safely on failure. The pythonserver implementation demonstrates each of these pillars in a way that is both practical and portable. The switching workflow begins with a single resolver that accepts either an interpreter executable path or a virtual environment directory. If the input is a file whose basename looks like a Python executable, the resolver treats it as such, and when the path sits under bin or Scripts it walks one directory up to infer the venv root. If the input is a directory, the resolver confirms a venv by checking for pyvenv.cfg or conda‑meta. Inputs...
