Quoting Guido van Rossum Aug 20 2015. Thread "Properties for classes possible?"

https://mail.python.org/pipermail/python-ideas/2015-August/035354.html

{{{
 think it's reasonable to propose @classproperty as a patch to CPython. It
needs to be C code. Not sure about the writable version. The lazy=True part
is not appropriate for th he stdlib (it's just a memoize pattern).
}}}

The solution I use at the moment:

{{{
# From http://stackoverflow.com/a/5192374/633961
class classproperty(object):
    def __init__(self, f):
        self.f = f
    def __get__(self, obj, owner):
        return self.f(owner)
}}}

According to Terry Jan Reedy the next step is to find
someone to translate this to C.

Sorry, my C knowledge is limited. Can anybody help?

A read-only classproperty is fairly trivial to implement in pure Python and has been done.

A good reason to have a classproperty implementation in CPython would be to support settable/deleteable classproperties.  The problem is that can't be done with the descriptor protocol on its own without a custom metaclass.  classproperty would have to somehow be special-cased, perhaps in type_setattro, say.  I don't know if that can just be done lightly.

Otherwise I don't see the advantage of adding a classproperty type to CPython?

I've posted a counter-proposal on python-ideas:

https://mail.python.org/pipermail/python-ideas/2015-August/035614.html

Basically: instead of "classproperty", add a more lenient alternative to classmethod which allows composition.  I called it "classresolved".

class classresolved:
    def __init__(self, wrapped):
        self.wrapped = wrapped
    def __get__(self, obj, cls):
        try:
            getter = self.wrapped.__get__
        except AttributeError:
            return self.wrapped
        return getter(cls, type(cls))

I also posted a broader proposal:

https://mail.python.org/pipermail/python-ideas/2015-August/035615.html