Not just the Adafruit matrices use the HT16K33 chip. Their 7- and 14-segment displays use it as well, and here's a library that supports those: https://bitbucket.org/thesheep/micropython-ht16k33/tip/ht16k33_seg.py

It requires the matrix library to work, as it reuses some of the code. I decided to put it in a separate file, because it comes with some data defining all the letters and digits, and that would waste memory if you only wanted to use the matrix part of the code.

Some example code:

import time
from machine import I2C, Pin
from ht16k33_seg import Seg14x4

i2c = I2C(sda=Pin(4), scl=Pin(5))
display = Seg14x4(i2c)

display.brightness(8)
for c in "Hello world!":
    display.push(c)
    display.show()
    time.sleep(0.25)