Sets the polarity of the motor. With `normal` polarity, a positive duty
        cycle will cause the motor to rotate clockwise. With `inversed` polarity,
        a positive duty cycle will cause the motor to rotate counter-clockwise.
        Valid values are `normal` and `inversed`.

def polarity(self):
        """
        Sets the polarity of the motor. With `normal` polarity, a positive duty
        cycle will cause the motor to rotate clockwise. With `inversed` polarity,
        a positive duty cycle will cause the motor to rotate counter-clockwise.
        Valid values are `normal` and `inversed`.
        """
        self._polarity, value = self.get_attr_string(self._polarity, 'polarity')
        return value