Old project that did exactly what I would like see done for the esp platform ... but for the Teensy 3.1 ARM development board - https://github.com/10bulls/libmpython
A top secret Seed-Studio project to bring MicroPython & Arduino together
A tiny python-inspired language for embedded computing (Bare-metal)
A lean and efficient Python implementation for microcontrollers (Bare-metal)
Older stuff ...
* CircuitPython 4.0.0 and later does not support esp8266 boards.