def test_powers_of_two(self):
"""Test iterator for all powers of two less than a given number."""
pow2 = powers_of_two(70)
self.assertEqual(next(pow2), 1)
self.assertEqual(next(pow2), 2)
self.assertEqual(next(pow2), 4)
self.assertEqual(next(pow2), 8)
self.assertEqual(next(pow2), 16)
self.assertEqual(next(pow2), 32)
self.assertEqual(next(pow2), 64)
pow2 = powers_of_two(2)
self.assertEqual(next(pow2), 1)
self.assertEqual(next(pow2), 2)
def test_powers_of_two_produces_an_actual_generator(self):
g = powers_of_two(3)
self.assertEqual(g.next(), 1)
self.assertEqual(g.next(), 2)
self.assertRaises(StopIteration, g.next)
def test_powers_of_two_produces_correct_sequences(self):
self.assertEqual(list(powers_of_two(60)), [1, 2, 4, 8, 16, 32])
self.assertEqual(list(powers_of_two(63)), [1, 2, 4, 8, 16, 32])
self.assertEqual(list(powers_of_two(64)), [1, 2, 4, 8, 16, 32, 64])
self.assertEqual(list(powers_of_two(0)), [])
self.assertEqual(list(powers_of_two(1)), [1])
def test_powers_of_two_produces_an_actual_generator(self):
g = powers_of_two(3)
self.assertEqual(g.next(), 1)
self.assertEqual(g.next(), 2)
self.assertRaises(StopIteration, g.next)
def test_powers_of_two_produces_correct_sequences(self):
self.assertEqual(list(powers_of_two(60)), [1, 2, 4, 8, 16, 32])
self.assertEqual(list(powers_of_two(63)), [1, 2, 4, 8, 16, 32])
self.assertEqual(list(powers_of_two(64)), [1, 2, 4, 8, 16, 32, 64])
self.assertEqual(list(powers_of_two(0)), [])
self.assertEqual(list(powers_of_two(1)), [1])