I would sort of expect that running python on a small microcontroller would run into the same sorts of problems that one can see with with C++; the neat features that you expected would make your life easier turn out to be "expensive", and you wind up with a usable subset that isn't much different than C. ("Why yes, I can program in java and python and perl and C++ and they all end up looking like C!")
OTOH, BASIC interpreters have a long history of running on smallish micros (though usually with lots of RAM.)