intent: Adding a 1-D Array to a 3-D array in Numpy
rewritten_intent: adding a 1-d array `[1, 2, 3, 4, 5, 6, 7, 8, 9]` to a 3-d array `np.zeros((6, 9, 20))`
snippet: np.zeros((6, 9, 20)) + np.array([1, 2, 3, 4, 5, 6, 7, 8, 9])[(None), :, (None)]