Python Operating System

[PythonUsr]

Although I know for a fact that an Operating System can be written in
Python, I need to ask some questions to the more advanced users of
Python.

Uuu and Cleese are two operating systems that were / are written in
Python. Does anyone use them? If so, how do they function / feel? Do
they have a graphical mode and a command line mode, such as Linux does?

How hard would it be to write a full blown bootable operating system in
Python? With a command line and a GUI in all? Would the books you see
on the shelves at, say, Barnes and Noble, do the trick? Or do you need
to dig deeper into the language than what is taught in the 1,000 page
books?

Thanks in advance, and I am truly sorry if this has been a discussion
before in this group!

-- Alex (PythonUsr)