weak reference callback
lists at cheimes.de
Sat Aug 29 23:14:17 CEST 2009
Paul Pogonyshev wrote:
> Is weak reference callback called immediately after the referenced
> object is deleted or at arbitrary point in time after that? I.e. is
> it possible to see a dead reference before the callback is called?
> More formally, will this ever raise?
> callback_called = False
> def note_deletion (ref):
> callback_called = True
> x = ...
> ref = weakref.ref (x, note_deletion)
> if ref () is None and not callback_called:
> raise RuntimeError ("reference is dead, yet callback hasn't been called yet")
Yes, you'll definitely see a RuntimeError because you forgot to declare
callback_called as a global variable. :)
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