def angleBetweenTwoPoints(p1, p2):
    '''return in angle in deg'''
    #old way 0-360
    a1 = math.atan2(p1[1], p1[0])
    a2 = math.atan2(p2[1], p2[0])
    angle1 = (a1 - a2) % (2 * math.pi)
    angle1 = math.degrees(angle1)
    #print 'first way of calc angle:', angle1

    #new way seems to work better -180 - 180
    x = p2[0] - p1[0]
    y = p2[1] - p1[1]
    angle2 = math.atan2(y, x) * (180 / math.pi)
    #print 'second way:', angle2

    return round(angle2, 2)