code: def delta(self, other):
          '''
          Return the error between this and another bearing. This will be an
          angle in degrees, positive or negative depending on the direction of
          the error.
          
              self   other
                \      /
                 \    /
                  \__/
                   \/ <- angle will be +ve
  
              other   self
                \      /
                 \    /
                  \__/
                   \/ <- angle will be -ve        
  
          :param other: bearing to compare to
          :type other: Bearing
  
          :returns: error angle
          :rtype: float
          '''
          difference = float(other) - float(self)
          while difference < -180:
              difference += 360
          while difference > 180:
              difference -= 360
          return differencf delta(self, other):
          '''
          Return the error between this and another bearing. This will be an
          angle in degrees, positive or negative depending on the direction of
          the error.
          
              self   other
                \      /
                 \    /
                  \__/
                   \/ <- angle will be +ve
  
              other   self
                \      /
                 \    /
                  \__/
                   \/ <- angle will be -ve        
  
          :param other: bearing to compare to
          :type other: Bearing
  
          :returns: error angle
          :rtype: float
          '''
          difference = float(other) - float(self)
          while difference < -180:
              difference += 360
          while difference > 180:
              difference -= 360
          return difference
docs: Return the error between this and another bearing. This will be an
          angle in degrees, positive or negative depending on the direction of
          the error.
          
              self   other
                \      /
                 \    /
                  \__/
                   \/ <- angle will be +ve
  
              other   self
                \      /
                 \    /
                  \__/
                   \/ <- angle will be -ve        
  
          :param other: bearing to compare to
          :type other: Bearing
  
          :returns: error angle
          :rtype: float