Am 04.10.2005 um 04:25 schrieb [EMAIL PROTECTED]:
> As the OP suggests, decoding with a codec like mac-roman or
> iso8859-1 is very
> slow compared to encoding or decoding with utf-8. Here I'm working
> with 53k of
> data instead of 53 megs. (Note: this is a laptop, so it's possible
> that
> thermal or battery management features affected these numbers a
> bit, but by a
> factor of 3 at most)
>
> $ timeit.py -s "s='a'*53*1024; u=unicode(s)" "u.encode('utf-8')"
> 1000 loops, best of 3: 591 usec per loop
> $ timeit.py -s "s='a'*53*1024; u=unicode(s)" "s.decode('utf-8')"
> 1000 loops, best of 3: 1.25 msec per loop
> $ timeit.py -s "s='a'*53*1024; u=unicode(s)" "s.decode('mac-roman')"
> 100 loops, best of 3: 13.5 msec per loop
> $ timeit.py -s "s='a'*53*1024; u=unicode(s)" "s.decode('iso8859-1')"
> 100 loops, best of 3: 13.6 msec per loop
>
> With utf-8 encoding as the baseline, we have
> decode('utf-8') 2.1x as long
> decode('mac-roman') 22.8x as long
> decode('iso8859-1') 23.0x as long
>
> Perhaps this is an area that is ripe for optimization.
For charmap decoding we might be able to use an array (e.g. a tuple
(or an array.array?) of codepoints instead of dictionary.
Or we could implement this array as a C array (i.e. gencodec.py would
generate C code).
Bye,
Walter Dörwald
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