How to read the affine registration transformation parameters

[cswin]

I am using the command function included in https://www.doc.ic.ac.uk/~dr/software/usage.html
to do 3D surface affine registration.
such as:
sareg mesh-a.vtk mesh-b.vtk -dofin srreg-b-a.vtk -dofout sareg-b-a.vtk

How can I read the sareg-b-a.vtk into my program with python?

Thank you very much.
Best,
Peng