b_idx = np.random.randint(0, 9, 90)
>>> b_idx
array([0, 1, 5, 4, 7, 2, 7, 0, 0, 4, 2, 2, 3, 5, 6, 4, 7, 0, 3, 2, 7, 3,
8, 5, 4, 3, 1, 8, 6, 6, 5, 5, 3, 2, 2, 2, 0, 4, 8, 1, 5, 3, 2, 6,
2, 3, 3, 3, 0, 4, 5, 1, 4, 0, 6, 7, 6, 3, 4, 7, 8, 5, 8, 6, 7, 6,
6, 6, 3, 1, 6, 1, 4, 6, 4, 7, 4, 8, 6, 6, 7, 7, 1, 0, 6, 0, 4, 1,
5, 2])
原文：https://www.cnblogs.com/alexYuin/p/9597730.html