def test_ninety_degress_angle(self):
v1 = Vector(0, 1, 0)
v2 = Vector(1, 0, 0)
expected = math.pi / 2
self.assertEqual(v1.angle_between(v2), expected)
def test_180_degrees(self):
v1 = Vector(-1, 0, 0)
v2 = Vector(1, 0, 0)
self.assertEqual(v1.angle_between(v2), math.pi)
def test_angle_between(self):
v1 = Vector(1, 2, 3)
v2 = Vector(4, 5, 6)
expected = 0.22572613
self.assertAlmostEqual(expected, v1.angle_between(v2), 8)