[Python-Dev] Performance of u() (original) (raw)

Antoine Pitrou solipsis at pitrou.net
Sun Feb 26 18:53:31 CET 2012


On Sat, 25 Feb 2012 19:13:26 -0800 Guido van Rossum <guido at python.org> wrote:

If this can encourage more projects to support Python 3 (even if it's only 3.3 and later) and hence improve adoption of Python 3, I'm all for it.

A small quibble: I'd like to see a benchmark of a 'u' function implemented in C.

Even without implementing it in C, caching the results makes it much less prohibitive in tight loops:

if sys.version_info >= (3, 0): def u(value): return value else: def u(value, _lit_cache={}): if value in _lit_cache: return _lit_cache[value] s = _lit_cache[value] = unicode(value, 'unicode-escape') return s

u'\N{SNOWMAN}barbaz' -> 100000000 loops, best of 3: 0.00928 usec per loop u('\N{SNOWMAN}barbaz') -> 10000000 loops, best of 3: 0.15 usec per loop u'foobarbaz_%d' % x -> 1000000 loops, best of 3: 0.424 usec per loop u('foobarbaz_%d') % x -> 1000000 loops, best of 3: 0.598 usec per loop

Regards

Antoine.



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