[Python-Dev] Hashing proposal: change only string-only dicts (original) (raw)

Barry Warsaw barry at python.org
Wed Jan 18 13:30:10 CET 2012

On Jan 18, 2012, at 08:19 AM, Martin v. Löwis wrote:

My concern is not about breaking doctests: this proposal will also break them. My concern is about applications that assume that hash(s) is stable across runs, and we do have reports that it will break applications.

I am a proponent of doctests, and thus use them heavily. I can tell you that the issue of dict hashing (non-)order has been well known for years and I have convenience functions in my own doctests to sort and print dict elements. Back in my Launchpad days (which has oodles of doctests), many years ago we went on a tear to fix dict printing when some change in Python caused them to break. So I'm not personally worried that such a change would break any of my own code.

Even though I hope anybody who uses doctests has their own workarounds for this, I still support being conservative in default behavior for stable releases, because it's the right thing to do for our users.

-Barry

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