[Python-Dev] The current dict is not an "OrderedDict"

[Guido van Rossum]

I'll probably get complaints because I'm not waiting for the benchmark
results to come in, but I think I've seen enough.

To me the only defensible behavior *other than the pre-3.6 behavior* is
that after deletions the order remains preserved and new insertions happen
at the end -- i.e. the same where they would go if the deleted items were
never inserted.

I find it hard to believe that there would be a speed difference that's
noticeable outside micro-benchmarks or applications making extreme use of
dicts.

PS. It seems odd that people arguing that the behavior after deletions
doesn't matter are also arguing that deletions are uncommon? Surely there
should be no speed penalty if you never delete anything from a dict, so if
you believe deletions are rare anyway, why would you care about paying a
bit extra for them?

-- 
--Guido van Rossum (python.org/~guido)
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