def test_different_length_lists(self):
in1 = [1, 2, 3]
in2 = [4, 5, 6, 7, 8]
in3 = [9]
out1 = [1, 4, 9, 2, 5, 3, 6, 7, 8]
self.assertIterableEqual(interleave(in1, in2, in3), out1)
self.assertIterableEqual(
interleave([1, 2], [3], [4, 5, 6], [7, 8], [9]),
[1, 3, 4, 7, 9, 2, 5, 8, 6],
)
def test_response_is_iterator(self):
in1 = [1, 2, 3]
in2 = [4, 5, 6]
squares = (n**2 for n in in1)
output = interleave(in1, in2)
self.assertIs(iter(output), iter(output))
output = interleave(squares, squares)
self.assertEqual(next(output), 1)
self.assertEqual(next(output), 4)
self.assertEqual(next(squares), 9)
iterator = interleave(count(), count())
self.assertEqual(next(iterator), next(iterator))
def test_more_than_two_arguments(self):
in1 = [1, 2, 3]
in2 = [4, 5, 6]
in3 = [7, 8, 9]
out = [1, 4, 7, 2, 5, 8, 3, 6, 9]
self.assertIterableEqual(interleave(in1, in2, in3), out)
def test_non_sequences(self):
in1 = [1, 2, 3, 4]
in2 = (n**2 for n in in1)
out = [1, 1, 2, 4, 3, 9, 4, 16]
self.assertIterableEqual(interleave(in1, in2), out)
def test_none_value(self):
in1 = [1, 2, 3, None]
in2 = [4, 5, 6, 7]
out = [1, 4, 2, 5, 3, 6, None, 7]
self.assertIterableEqual(interleave(in1, in2), out)
def test_four_items_each(self):
in1 = [1, 2, 3, 4]
in2 = [5, 6, 7, 8]
out = [1, 5, 2, 6, 3, 7, 4, 8]
self.assertIterableEqual(interleave(in1, in2), out)
def test_two_items_each(self):
self.assertIterableEqual(interleave([1, 2], [3, 4]), [1, 3, 2, 4])
def test_single_item_each(self):
self.assertIterableEqual(interleave([1], [2]), [1, 2])
def test_empty_lists(self):
self.assertIterableEqual(interleave([], []), [])