How to access TBuffer object through PyRoot

I am trying to get TBuffer object from root file by using PyRoot. What I have done is

f = ROOT.TFile("path/to/root_file")
key_lst_1 = f.GetListOfKeys()
iter_1 = ROOT.TIter(key_lst_1)
k = iter1.Next()
buf = k.GetBuffer()

And I got error message,

SystemError: char* TKey::GetBuffer() =>
    problem in C++; program state has been reset

Does that mean we can’t access TBuffer object through Python?
Any help would be appreciated!

Is not TBuffer from GetBuffer(), but from GetBufferRef().