[Python-Dev] Optimizing list.sort() by checking type in advance

[Tim Peters]

[Terry Reedy]
>
> This seems like a generic issue with timing mutation methods
> ...
> But I am sure Tim worked this out in his test code, which should be
> reused, perhaps updated with Viktor's perf module to get the most
> stable timings possible.

sortperf.py is older than me ;-)  It's not at all intended to give
fine-grained timings:  it's a sledgehammer than runs each case _only
once_, to confirm/refute _big_ changes.

So it's useful qualitatively when a "big claimed change" is at issue,
but useless for quantifying beyond "wow!" or "ouch!" or "meh".

Since this is a "big claimed change", a "wow!" outcome is good-enough
confirmation.  And a "meh" outcome would be almost good enough for
cases where the new specializations don't apply - although I haven't
seen any numbers from sortperf.py for those cases yet.  I expect a
"meh" outcome for those, based on reasoning - but may be surprised by
reality.