常用,常忘 1.随机矩阵 np.random.rand(4,3) array([[ 0.06679473, 0.71073515, 0.5694172 ], [ 0.95018143, 0.60161401, 0.8076899 ], [ 0.40341822, 0.72154255, 0.92283012], [ 0.81143322, 0.87853742, 0.38013707]]) np.random.randint(0,10,(4,3)) array([[1, 9, 5], [6, 1