The marshal format used by pyc files is explicitly documented[1] to be unsafe, just a fast way to cache the compiled byte code to a .pyc file next to the .py source file. The Python VM is not a sandbox so there has been no need for an untrusted bytecode format.

[1] see big red warning box at https://docs.python.org/3/library/marshal.html

Not yet, currently sitting there with around 2000 unique cases and wondering how to do it efficiently.