How do I code an Omni-Wheel Drivetrain to turn a given amount of degrees? (Custom Code)

I am trying to code a way for the robot to turn a given amount of degrees, but I don’t want to use the drivetrain class in case we have drift (slight turn while going straight). How do I calculate how much to turn the motors to turn the much?

In case you need it, here is info about our drivetrain:
Wheels: Omni Wheels
Gear Ratio: 3:2
Width: 4 inches
Length 7 inches

I am using python