Python class property decorator only support getattr

classproperty.py

class ClassPropertyDescriptor(property):
    u"""
    class property descriptor
    """

    def __get__(self, obj, objtype=None):
        if self.fget is None:
            raise AttributeError("unreadable attribute")
        return self.fget.__get__(obj, objtype)()


def classproperty(func):
    if not isinstance(func, (classmethod, staticmethod)):
        func = classmethod(func)

    return ClassPropertyDescriptor(func)


class Foo(object):
    _var = 5

    @classproperty
    def var(cls):
        return cls._var