Thanks for the reply! I'm not concerned about hiding the source code in a fundamental way. The condition that needs to be satisfied is that independent validators (in the organisation) must not "have access" to the source code.
Crunching the source is an interesting idea that could achieve that end, but it seems fraught with problems like maintaining consistency between renaming objects in a module and renaming where imports happen. -- https://mail.python.org/mailman/listinfo/python-list