[Python-Dev] [ 654866 ] pickle and cPickle not equivalent

[Guido van Rossum]

> Here is another thought that might outway the performance concerns: for 
> whatever reason, all instances of new-style classes (even with refcount 
> == 1, or perhaps because they don't have a refcount == 1) *are* getting 
> put in the cPickle memo.

Pickling of new-style classes is currently done using a Python helper.
I am still hoping that I'll be able to dig myself out of the pile of
Zope work that I'm currently under, and then I'd like to work on
making pickling of new-style classes a lot more efficient.  So please
don't use this argument to cripple pickle any further.

--Guido van Rossum (home page: http://www.python.org/~guido/)