As long as you can interface the pythin code from C++, yes. OMNeT++ kernel is nothing else than just a C++ library. As long as the Python code does not need to access the OMNET++ API is should be a fairly easy task. I guess this is the case as you have already implemented the code in python without the OMNeT++ API.
I strongly suggest to take a look at the integration branch (that will becom INET 3.0). A lot of work went into the routing infrastructure and some of my colleagues implemented AODV/DYMO from scratch using it.
We are right now preparing a development snapshot (2.99.0)
Rudolf