-----Original Message----- From: "Martin v. Löwis" [mailto:martin@v.loewis.de] Sent: 3. ágúst 2010 20:48 To: Kristján Valur Jónsson Cc: Python-Dev Subject: Re: [Python-Dev] pickle output not unique
I just wanted to point this out. We'll attempt some local workarounds here, but it should otherwise be simple to modify pickling to optionally turn off this optimization and always generate the same output irrespective of the internal reference counts of the objects.
I think there are many other instances where values that compare equal pickle differently in Python. By relying on this property for hashing, you are really operating on thin ice.
Well, it is not _that_ dangerous. It just causes cache misses when they wouldn't be expected. But since this has been brought up and dismissed in issue 8738, I won't pursue this further. K