I've been programming in Python for quite a few years and I'm intimately familiar with the language. I've also written several pure Python modules as well as CPython modules (written in C, usable from CPython, the original Python interpreter) for personal use.
The approach used on your project would depend on what exactly needs to be done. If you plan on using only the official CPython interpreter, I'd probably compile the existing C++ code as a library and write a CPython C extension which would call the library. If you need full portability between Python interpreters, we'd have to think of other strategies, probably rewriting the existing C++ codebase to Python from scratch (I'm assuming it's not a very complex program).
The details are negotiable and I can start today.