def angle(self, a):
        '''Computes the angle between a and b, and returns the angle in
        degrees.

        >>> Vector(100, 0).angle((0, 100))
        -90.0
        >>> Vector(87, 23).angle((-77, 10))
        -157.7920283010705

        '''
        angle = -(180 / math.pi) * math.atan2(
            self[0] * a[1] - self[1] * a[0],
            self[0] * a[0] + self[1] * a[1])
        return angle
dataset/ETHPy150Open kivy/kivy/kivy/vector.py/Vector.angle/original