Toying with the idea of a `classproperty` in Python.

classproperty.py

# Lets define a `classproperty` such that it works as a property on both
# an object and it's type:

class classproperty(object):

    __slots__ = ('getter', )
    
    def __init__(self, getter):
        self.getter = getter

    def __get__(self, obj, cls):
        return self.getter(cls, obj)


# A very basic demo:

class Example(object):

    @classproperty
    def prop(cls, obj):
        return obj or cls


x = Example()
assert x.prop is x
assert Example.prop is Example


# I'm considering using this for defining ACLs on a model, so that the
# `__acl__` attribute on classes or objects can be used:

class MyModel(object):

    visible = True

    @classproperty
    def __acl__(cls, obj):
        yield 'ALLOW ADMIN create'
        if obj and obj.visible:
            yield 'ALLOW ANY read'

print '\n'.join(MyModel.__acl__)
print
print '\n'.join(MyModel().__acl__)