Google's Starlark is a pretty good python-like language that does a lot of what you want, we use it at my company to run untrusted code. It's not exactly python

Google's Starlark is a pretty good python-like language that does a lot of what you want, we use it at my company to run untrusted code. It's not exactly python, but a pretty good subset. It's deterministic, hermetically sealed and non-Turing complete.