Cached property in Python with invalidation

cproperty.py

import functools

_invalid = object()

def cached_property(_get, _set, _del=None):
    name = _get.__name__
    mangled = "_" + name

    @functools.wraps(_get)
    def cached_get(inst):
        d = inst.__dict__
        try:
            value = d[mangled]
            if value is not _invalid:
                return value
        except KeyError:
            pass

        value = _get(inst)
        d[mangled] = value
        return value

    @functools.wraps(_set)
    def set_and_invalidate_cache(inst, value):
        _set(inst, value)
        d = inst.__dict__
        d[mangled] = _invalid

    @functools.wraps(_del)
    def del_and_invalidate_cache(inst, value):
        _del(inst, value)
        d = inst.__dict__
        d[mangled] = _invalid

    return property(
        cached_get,
        set_and_invalidate_cache,
        del_and_invalidate_cache if _del is not None else None,
        )