[Python-Dev] chained assignment weirdity

[Chris Angelico]

On Thu, Nov 8, 2012 at 1:54 AM, Guido van Rossum <guido at python.org> wrote:
> On Wed, Nov 7, 2012 at 4:13 AM, Ned Batchelder <ned at nedbatchelder.com> wrote:
>> We've gone out of our way to
>> maintain backward compatibility with the implemented behavior before
>> (ordering of dict keys, for example).
>
> Not sure what you're referencing here -- didn't we just start
> randomizing hashing?

Hash randomization could have been quietly introduced as a security
fix and backported to old versions. But since applications might have
depended on dict iteration order, it wasn't - old versions of Python
won't randomize hashes unless you set an environment variable. That's
taking care of old code, even when that old code is depending on
non-spec behaviour.

ChrisA