[Python-3000] characters data type

[Guido van Rossum]

Can you please post the benchmarking code?

On 5/4/06, Josiah Carlson <jcarlson at uci.edu> wrote:
>
> Josiah Carlson <jcarlson at uci.edu> wrote:
> > Good point.  Making the input 1025 bytes, and performing block[:-1]
> > resulted in a running time of 13.94 seconds.
>
> I just thought of a better way of benchmarking list-like over-allocation
> semantics.
>
> For assumed smaller-sized writes:
>
> Use an array, and manually extend using extensions which are about as
> long as list overallocation, which would under-count the amount of time
> it would take to construct bytes object with generally small incremental
> writes.
>
> Then, use the smallest overallocation size as the presumed size of
> writes in the list.append()/''.join() case.  This should reasonably
> count the amount of time to generate the string in this case.
>
> If the under-counting for list-like overallocation is about the same or
> slower than the append/join, then append/join is going to be faster in
> practice for small writes.
>
>
> For larger blocks, do the same thing, only increase the 'overallocations'
> to be at least as large as the the assumed block size.
>
>                135 byte blocks    1k blocks
> append/join:     28.05s             12.11s
> list-like:       31.21s             31.50s
>
> Seems to be a clear win for append/join on both 135 byte and 1k blocks
> for constructing a 16 meg string. Reducing block size to 64 bytes gives
> list-like overallocation the benefit (append/join jumps to 50+
> seconds), which tells us that for very short blocks, list-like
> overallocation wins, but for blocks of expected ~135 bytes or larger on
> my machine, append/join wins.
>
>
>  - Josiah
>
>


--
--Guido van Rossum (home page: http://www.python.org/~guido/)