> Wrong, because the object itself could be pickleable but refer to a
> different object which is non-pickleable. I want to know whether the
> object itself, without any object it refers to, is pickleable.

I think you're being too picky. Unless you're manually added stuff
to your Lock's attributes, there isn't a practical difference between
the two situations.

> Also, pickling an object could be very resource-intensive, depending
> on its size.

Well, this is a Lock here, not an ISO file.