This documentation refers to a feature which is only available within the simulator.

The sr.robot library contains support for using a simulated compass unit on the robot. This allows robots to determine the direction it’s facing in the arena.

from sr.robot import *
R = Robot()
heading = R.compass.get_heading()

When called, the get_heading method will return the heading of the robot in radians as a float. The heading is in the range 0 to tau (2π), where 0 is the robot facing directly North, and values increasing clockwise.