New submission from Raymond Hettinger: The code for dict_equal() in Objects/dictobject.c currently loops over the key/value pairs in self and uses PyDict_GetItem() to check for the corresponding key/value pair in the other dictionary. This causes an unnecessary call to PyObject_Hash().
Instead, the code should loop over the key/value/hash triplets in self and do a direct lookup in the other dictionary with " ep = (otherdict->ma_lookup)(otherdict, key, hash)". The reuses the known hash value for the key; thereby avoiding the potentially slow call to PyObject_Hash(). See _PyDict_Contains() for an example of how to do a lookup when the hash value is already known. Note, the optimized path should be used only when PyDict_CheckExact() is true. ---------- components: Interpreter Core keywords: easy messages: 176453 nosy: rhettinger priority: low severity: normal status: open title: Optimize dict equality test type: performance versions: Python 3.4 _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue16562> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
