Recently got to use Grove - I2C Motor Driver (TB6612FNG) with my Raspberry Pi.
For this, I wrote and released my own port of Arduino library for this module to Raspberry Pi and python3.
This library also includes easing functions to control your motors with smooth transitions.Easing functions are available for dc motors only.
You can check it out here: https://pypi.org/project/raspberry-i2c-tb6612fng/
And the Wiki page is here: https://github.com/MarkusBansky/raspberry-i2c-tb6612fng/wiki
Please feel free to use and suggest any useful things, thanks.