Python 把矩阵转为list

>>> from numpy import *
>>> a = mat([3,2,1])
>>> a
matrix([[3, 2, 1]])
>>> b = a.tolist()
>>> b
[[3, 2, 1]]
>>> b[0]
[3, 2, 1]
>>> a = mat([[3],[2],[1]])
>>> a
matrix([[3],
[2],
[1]])
>>> b = a.tolist()
>>> b
[[3], [2], [1]]
>>> b[0]
[3]