Why is python not written in C++ ?

[candide]

Python is an object oriented langage (OOL). The Python main 
implementation is written in pure and "old" C90. Is it for historical 
reasons?

C is not an OOL and C++ strongly is. I wonder if it wouldn't be more 
suitable to implement an OOL with another one.

Has it ever been planned to rewrite in C++ the historical implementation 
(of course in an object oriented design) ?