A= [[1, 2, 3], [4, 5, 6]] np.append(A, [[7, 8, 9]], axis=0) >> array([[1, 2, 3], [4, 5, 6], [7, 8, 9]]) #or np.r_[A,[[7,8,9]]]
x1 = [1, 2] x2 = [1, 2] print(np.add(x1, x2)) # [2, 4]
