>>> import numpy as np
>>> A = np.mat('1 2;3 4')
>>> A
matrix([[1, 2],
        [3, 4]])
>>> A[0],A[1] = A[1],A[0]
>>> A
matrix([[3, 4],
        [3, 4]])
>>> 

A[[0,1]] = A[[1,0]]
// 上面相当于 A[[0,1],:] = A[[1,0],:]