[Python-Dev] Usage of += on strings in loops in stdlib (original) (raw)

Christian Tismer tismer at stackless.com
Wed Feb 13 02:25:09 CET 2013

On 13.02.13 02:09, Alexandre Vassalotti wrote:

On Tue, Feb 12, 2013 at 1:44 PM, Antoine Pitrou <solipsis at pitrou.net_ _<mailto:solipsis at pitrou.net>> wrote:

It's idiomatic because strings are immutable (by design, not because of an optimization detail) and therefore concatenation has to imply building a new string from scratch.

Not necessarily. It is totally possible to implement strings such they are immutable and concatenation takes O(1): ropes are the canonical example of this.

Ropes have been implemented by Carl-Friedrich Bolz in 2007 as I remember. No idea what the impact was, if any at all. Would ropes be an answer (and a simple way to cope with string mutation patterns) as an alternative implementation, and therefore still justify the usage of that pattern?

-- Christian Tismer :^) <mailto:tismer at stackless.com> Software Consulting : Have a break! Take a ride on Python's Karl-Liebknecht-Str. 121 : Starship http://starship.python.net/ 14482 Potsdam : PGP key -> http://pgp.uni-mainz.de phone +49 173 24 18 776 fax +49 (30) 700143-0023 PGP 0x57F3BF04 9064 F4E1 D754 C2FF 1619 305B C09C 5A3B 57F3 BF04 whom do you want to sponsor today? http://www.stackless.com/

-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.python.org/pipermail/python-dev/attachments/20130213/cad9f55c/attachment-0001.html>

More information about the Python-Dev mailing list