转换三维矩阵两次？

Question

给定numpy中的3d矩阵，如何将矩阵A转换为矩阵B，然后将B转置回A。

我似乎能够将A转换为矩阵：

>>> import numpy
>>> a = numpy.random.rand(3,3,3)
>>> print a
[[[ 0.69774026  0.14510969  0.12476703]
  [ 0.02631041  0.61497379  0.86985018]
  [ 0.14114129  0.87731903  0.76020481]]

 [[ 0.66507441  0.16093391  0.19799549]
  [ 0.56614043  0.17268869  0.39641231]
  [ 0.61712168  0.71372674  0.32510021]]

 [[ 0.50997888  0.75687504  0.69902029]
  [ 0.50366012  0.22187467  0.58894526]
  [ 0.8726912   0.4319045   0.43687999]]]
>>> b = a.transpose(0,2,1)
>>> print b
[[[ 0.69774026  0.02631041  0.14114129]
  [ 0.14510969  0.61497379  0.87731903]
  [ 0.12476703  0.86985018  0.76020481]]

 [[ 0.66507441  0.56614043  0.61712168]
  [ 0.16093391  0.17268869  0.71372674]
  [ 0.19799549  0.39641231  0.32510021]]

 [[ 0.50997888  0.50366012  0.8726912 ]
  [ 0.75687504  0.22187467  0.4319045 ]
  [ 0.69902029  0.58894526  0.43687999]]]

但是我如何将矩阵b返回到矩阵a？