String performance regression from python 3.2 to 3.3

Chris Angelico rosuav at
Thu Mar 14 07:21:00 CET 2013

On Thu, Mar 14, 2013 at 1:35 PM, Terry Reedy <tjreedy at> wrote:
>On 3/13/2013 7:43 PM, Chris Angelico wrote:
>> It's complexity cost, though, and people would need to know when it
>> would be worth giving Python that switch to change its string format.
>> Plus, every C extension would need to cope with both formats. I
>> personally doubt it'd be worth it, but if you want to knock together a
>> patched CPython and get some timing stats, I'm sure this list or
>> python-dev will be happy to discuss the matter. :)
> I presume the smiley indicates that you know that python developers are too
> busy with real problems to have any interest in bogus solutions to bogus
> problems.

It indicates more that the list(s) would almost certainly open up with
quite a bit of discussion - especially this one. It's not hard to get
talk happening, as evidenced by the number of times we've already
discussed this very topic. Frankly, I doubt there'll be anything to
discuss - that the patched version will be consistently worse; but if
I've learned one thing about timings, it's that there are surprises
*everywhere*, so I'm not prepared to state categorically that it
*cannot* be better. (I will, however, state that I do not expect any
such improvement to be worth the trouble of writing it.)


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