The other way to look at it is that Lua has a simple enough binding interface that it's like a "high-level layer on top of C." So you can write C, or write Lua, and slop things around between them as necessary, run multiple interpreters, whatever you feel like.

Python is more focused on extending the language as a singular entity, and (not having actually written extensions) it seems to have more strenuous requirements.

Right now I'm focused on haXe, though, cause with that language, you get several platform options, including a Lua-like interpreter(Neko).