As you stress on "repeat the array ... rather than repeat each element",
you may want to consider tile as well:
>>> np.tile(a, [10,1])
array([[0, 1, 2],
[0, 1, 2],
[0, 1, 2],
[0, 1, 2],
[0, 1, 2],
[0, 1, 2],
[0, 1, 2],
[0, 1, 2],
[0, 1, 2],
[0, 1, 2]])