=[0]`` just like ``arr[:,0,:] = values`` is different from ``arr[:,[0],:] = values``. This is because of the difference between basic and advanced :ref:`indexing `. Examples -------- >>> import numpy as np >>> a = np.arange(6).reshape(3, 2) >>> a array([[0, 1], [2, 3], [4, 5]]) >>> np.insert(a, 1, 6) array([0, 6, 1, 2, 3, 4, 5]) >>> np.insert(a, 1, 6, axis=1) array([[0, 6, 1], [2, 6, 3], [4, 6, 5]]) Difference between sequence and scalars, showing how ``obj=[1]`` behaves different from ``obj=1``: >>> np.insert(a, [1], [[7],[8],[9]], axis=1) array([[0, 7, 1], [2, 8, 3], [4, 9, 5]]) >>> np.insert(a, 1, [[7],[8],[9]], axis=1) array([[0, 7, 8, 9, 1], [2, 7, 8, 9, 3], [4, 7, 8, 9, 5]]) >>> np.array_equal(np.insert(a, 1, [7, 8, 9], axis=1), ... np.insert(a, [1], [[7],[8],[9]], axis=1)) True >>> b = a.flatten() >>> b array([0, 1, 2, 3, 4, 5]) >>> np.insert(b, [2, 2], [6, 7]) array([0, 1, 6, 7, 2, 3, 4, 5]) >>> np.insert(b, slice(2, 4), [7, 8]) array([0, 1, 7, 2, 8, 3, 4, 5]) >>> np.insert(b, [2, 2], [7.13, False]) # type casting array([0, 1, 7, 0, 2, 3, 4, 5]) >>> x = np.arange(8).reshape(2, 4) >>> idx = (1, 3) >>> np.insert(x, idx, 999, axis=1) array([[ 0, 999, 1, 2, 999, 3], [ 4, 999, 5, 6, 999, 7]]) Fr3