AFAIK most of the important Python (core) routines are C++ cores with a Python call stack…This is at least the case for mathematical libs and so on we use.
@morixinguan: See the difference in implementaion strategy: Marlin is running at the (limited) hardware of a 3D printer, used to be Atmel 8 Bit “Arduino-Type” MCU (or today A3 or A4 Cores). Here Space and “hands on memory” is lethal. Klipper reduces the code on the printer to a minimum and ports the “time consuming” computations to a powerful (and hardware independant) external CPU (e.G. a RasPi). So even on a weak printer, you may enjoy the power of an up-to-date CPU. My Anycubic Mega S is running on a Arduino Mega Hardware 
Klipper for this printer is running on a Intel I3…
So if you want to replace the “up-to-date CPU” against another Atmel, you may do that, but you will be very alone with this solution…