[Python-Dev] PATCH submitted: Speed up + for string concatenation, now as fast as "".join(x) idiom

Bob Ippolito bob at redivi.com
Fri Oct 6 19:41:16 CEST 2006


On 10/6/06, Fredrik Lundh <fredrik at pythonware.com> wrote:
> Ron Adam wrote:
>
> > I think what may be missing is a larger set of higher level string functions
> > that will work with lists of strings directly.  Then lists of strings can be
> > thought of as a mutable string type by its use, and then working with substrings
> > in lists and using ''.join() will not seem as out of place.
>
> as important is the observation that you don't necessarily have to join
> string lists; if the data ends up being sent over a wire or written to
> disk, you might as well skip the join step, and work directly from the list.
>
> (it's no accident that ET has grown "tostringlist" and "fromstringlist"
> functions, for example ;-)

The just make lists paradigm is used by Erlang too, it's called
"iolist" there (it's not a type, just a convention). The lists can be
nested though, so concatenating chunks of data for IO is always a
constant time operation even if the chunks are already iolists.

-bob


More information about the Python-Dev mailing list