Similar to the ILI9341 driver. In fact, they are so similar, that I see some refactoring in their future to bring some common parts together. But for now, the code is here: https://bitbucket.org/thesheep/micropython-ili9341/src/tip/st7735.py

An example program:

from machine import Pin, SPI
import st7735
spi = SPI(miso=Pin(12), mosi=Pin(13, Pin.OUT), sck=Pin(14, Pin.OUT))
display = st7735.ST7735(128, 128, spi, Pin(2), Pin(4), Pin(5))
display.fill(0x7521)
display.pixel(64, 64, 0)