the pythonizations are three:
1. A C++ pyz to provide attr syntax. For example:

myfile.mydir.mysubdir.myHist.Draw()

2. A C++ pyz to allow users to invoke the templated method TDirectory::WriteObject<T>. For example:

h = ROOT.TH1F("h","",10, 0, 1)
myfile.WriteObject(h)

3. a Python pyz which implements TDirectory::Get in terms of the pythonized attr syntax