Update 2021: This can only work with Ren'Py 7.3, the newer versions use a vastly different type of built-in Python interpreter that are completely incompatible with any canonical Python interpreter.
The problem is that the Python runtime in RenPy is a stripped one. It's not the full Python. Don't even try to replace it with a full python runtime, you would have a really bad time.
The only feasible way is to use remote debugging. I assume you use Windows OS and have knowledge about programming, file system.
Demonstration Video
<Will add later>