如何使用另一个矩阵的第一列作为新的第一行,从中生成新的矩阵?

In [467]: alist = [5,6,4,3,4,5,3,2,5,3,1,2,2,3,2,1,3,1,1,1]
In [468]: arr = np.array(alist).reshape(4,5)
In [469]: arr
Out[469]: 
array([[5, 6, 4, 3, 4],
       [5, 3, 2, 5, 3],
       [1, 2, 2, 3, 2],
       [1, 3, 1, 1, 1]])
In [470]: arr.reshape(5,4)
Out[470]: 
array([[5, 6, 4, 3],
       [4, 5, 3, 2],
       [5, 3, 1, 2],
       [2, 3, 2, 1],
       [3, 1, 1, 1]])
In [471]: arr.reshape(5,4,order='F')
Out[471]: 
array([[5, 3, 2, 1],
       [5, 2, 1, 4],
       [1, 3, 3, 3],
       [1, 4, 5, 2],
       [6, 2, 3, 1]])

In [473]: np.rot90(_)
Out[473]: 
array([[1, 4, 3, 2, 1],
       [2, 1, 3, 5, 3],
       [3, 2, 3, 4, 2],
       [5, 5, 1, 1, 6]])