New submission from Thomas Heller <[EMAIL PROTECTED]>: This patch implements type.__instancecheck__ and type.__subclasscheck__, which speeds up isinstance and issubclass calls quite a bit.
See also issue #2303. Here are the performance figures for the current trunk version: Current SNV trunk: Using 2.6a1+ (trunk:62102, Apr 2 2008, 11:30:16) [MSC v.1500 32 bit (Intel)] isinstance(42, int) 1000000 loops, best of 3: 0.28 usec per loop isinstance(42, type) 1000000 loops, best of 3: 0.974 usec per loop issubclass(object, type) 1000000 loops, best of 3: 1.1 usec per loop issubclass(object, int) 1000000 loops, best of 3: 1.1 usec per loop issubclass(float, int) 1000000 loops, best of 3: 1.15 usec per loop Current trunk, patch applied: Using 2.6a1+ (trunk:62102M, Apr 2 2008, 11:21:32) [MSC v.1500 32 bit (Intel)] isinstance(42, int) 1000000 loops, best of 3: 0.274 usec per loop isinstance(42, type) 1000000 loops, best of 3: 0.524 usec per loop issubclass(object, type) 1000000 loops, best of 3: 0.661 usec per loop issubclass(object, int) 1000000 loops, best of 3: 0.662 usec per loop issubclass(float, int) 1000000 loops, best of 3: 0.731 usec per loop Python 2.5.2, for comparison: Using 2.5.2 (r252:60911, Feb 21 2008, 13:11:45) [MSC v.1310 32 bit (Intel)] isinstance(42, int) 1000000 loops, best of 3: 0.292 usec per loop isinstance(42, type) 1000000 loops, best of 3: 0.417 usec per loop issubclass(object, type) 1000000 loops, best of 3: 0.626 usec per loop issubclass(object, int) 1000000 loops, best of 3: 0.648 usec per loop issubclass(float, int) 1000000 loops, best of 3: 0.752 usec per loop ---------- files: type_instancecheck.diff keywords: patch, patch messages: 64842 nosy: theller severity: normal status: open title: Speed up isinstance and issubclass type: performance versions: Python 2.6 Added file: http://bugs.python.org/file9924/type_instancecheck.diff __________________________________ Tracker <[EMAIL PROTECTED]> <http://bugs.python.org/issue2534> __________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
