http://www.ogre3d.org/

you can't write a game like m&b in python using blender (if you mean the actual battle scenes)

python is my favourite language, though it performs about 11 times worse than a c++ application when using plain python loops. making a game as good as m&b would be very difficult alone as far as I know, if you're not experienced. c++ would certainly be required, m&b does not have that a high framerate in relatively large scale battles. using an engine like ogre3d from python could work though, but stuff like AI and other custom algorithms should be implemented in c++.

I'm starting to get pretty anxious about starting up a M&B mod, it has so much potential and yet it's so much easier to mod than rtw. wounder if I could get people interrested from this forum...