perhaps you can reorder this to make the common case first, e.g.

if (attr in obj.__dict__ or orig is sentinel        or isinstance(getattr(type(obj), attr), (property, types.FunctionType)):    origs[attr] = origelse:    raise ValueError(...)

Checking to types.FunctionType in the type is the same as checking for methods, and (as noted in the other PR, I think) won't give a wrong result if an unrelated bound method is assigned as instance var (self.foo = otherobj.method) -- at least I think this point should be fixed.

That makes sense. I agree the method from another object is a valid concern (sorry I didn't fully register it before).