Using numpy, is it possible to define a matrix in terms of other matrices?

Question

For example, I would like to do something like this

import numpy as np
A = np.array([[1,2,3],[4,5,6],[7,8,9]])
B = np.array([[1,1],[2,2],[3,3]])
C = np.zeros((2,2))
D = np.array([[A, B], [B.T, C]])

To produce a 5x5 ndarray with elements

1, 2, 3, 1, 1
4, 5, 6, 2, 2
7, 8, 9, 3, 3
1, 2, 3, 0, 0
1, 2, 3, 0, 0

Answer 1

一种方法是使用vstack和hstack ：

D = np.vstack((np.hstack((A, B)), np.hstack((B.T, C))))

Answer 2

你几乎可以得到使用np.r_这堆行和np.c_这堆列

D = np.r_[np.c_[A, B], np.c_[B.T, C]]