Can you please post the benchmarking code? On 5/4/06, Josiah Carlson <[EMAIL PROTECTED]> wrote: > > Josiah Carlson <[EMAIL PROTECTED]> 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/) _______________________________________________ Python-3000 mailing list Python-3000@python.org http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
