CircuitPython is “an education friendly open source derivative of MicroPython”. MicroPython is a port of Python to microcontroller environments; it can run on boards with very few resources such as the ESP8266. I’ve recently started experimenting with CircuitPython on a Wemos D1 mini, which is a small form-factor ESP8266 board. I had previously been using Mike Causer’s micropython-tm1637 for MicroPython to drive a 4 digit LED display. I was hoping to get the same code working under CircuitPython, but when I tried to build an image that included the tm1637 module I ran into: