2012/10/19 Benjamin Peterson <benja...@python.org>: > It would be interesting to see how common it is for strings which have > their hash computed to be compared.
I implemented a quick hack. When running "./python -m test test_os": Python calls PyUnicode_RichCompare() 15206 times with Py_EQ or Py_NE operator. In 41.4% (6295 calls), the hash of the two operands is known. In 41.2% (6262 times on 15206), the hash of the two operands are known *and are different*! The hit rate may depend since when the process was started. For example, in a fresh interpreter: the hit rate is only 7% (189 hit / 2703 calls). When running the test suite, the hit rate is around 80% (hashs are known in 90%) after running 70 tests. At the same time, the average of string length is 4.1 characters and quite all strings are pure ASCII. I create the issue http://bugs.python.org/issue16286 to discuss this optimization. Victor _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
