If you consider an ESP8266 an Arduino you can use MicroPython to program it. At that point you're not using an official Arduino board (well, Arduino Uno WiFi maybe), the Arduino libraries, or the Arduino IDE (unless you use Serial Monitor as your terminal) so it's a bit of a stretch to say "Arduino accepts Python" based on that.
There are probably ports of MicroPython for other microcontrollers but I doubt it's feasible on an AVR.