[Python-Dev] Usage of += on strings in loops in stdlib

[Amaury Forgeot d'Arc]

2013/2/13 Christian Tismer <tismer at stackless.com>

> On 13.02.13 15:27, Amaury Forgeot d'Arc wrote:
>
>
> 2013/2/13 Lennart Regebro <regebro at gmail.com>
>
>> On Wed, Feb 13, 2013 at 1:10 PM, Serhiy Storchaka <storchaka at gmail.com>
>> wrote:
>> > I prefer "x = '%s%s%s%s' % (a, b, c, d)" when string's number is more
>> than 3
>> > and some of them are literal strings.
>>
>>  This has the benefit of being slow both on CPython and PyPy. Although
>> using .format() is even slower. :-)
>
>
> Did you really try it?
> PyPy is really fast with str.__mod__, when the format string is a constant.
> Yes, it's jitted.
>
>
> How about the .format() style: Is that jitted as well?
> In order to get people to prefer .format over __mod__,
> it would be nice if PyPy made this actually _faster_ :-)


.format() is jitted as well.
But it's still slower than str.__mod__ (about 25%)
I suppose it can be further optimized.

-- 
Amaury Forgeot d'Arc
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