def test_flow(self):
x_flow = DataFlow.arrays([np.arange(10)], batch_size=4)
y_flow = DataFlow.arrays([np.arange(10, 17)], batch_size=4)
flow = DataFlow.gather([x_flow, y_flow])
self.assertIsInstance(flow, GatherFlow)
self.assertEqual((x_flow, y_flow), flow.flows)
batches = list(flow)
self.assertEqual(2, len(batches))
np.testing.assert_equal(np.arange(4), batches[0][0])
np.testing.assert_equal(np.arange(10, 14), batches[0][1])
np.testing.assert_equal(np.arange(4, 8), batches[1][0])
np.testing.assert_equal(np.arange(14, 17), batches[1][1])
def test_errors(self):
with pytest.raises(ValueError,
match='At least one flow must be specified'):
_ = DataFlow.gather([])
with pytest.raises(TypeError, match='Not a DataFlow'):
_ = DataFlow.gather([1])