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

[fwierzbicki at gmail.com]

On Tue, Feb 12, 2013 at 1:03 PM, Maciej Fijalkowski <fijall at gmail.com> wrote:
> Hi
>
> We recently encountered a performance issue in stdlib for pypy. It
> turned out that someone commited a performance "fix" that uses += for
> strings instead of "".join() that was there before.
>
> Now this hurts pypy (we can mitigate it to some degree though) and
> possible Jython and IronPython too.
Just to confirm Jython does not have optimizations for += String and
will do much better with the idiomatic "".join().

-Frank