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Fastpath for encoding unsorted dict to JSON #95385
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Patched pyperformance to use
json.dumps(sort_keys=True)before changes
### json_dumps ### Mean +- std dev: 14.0 ms +- 0.2 msafter changes
### json_dumps ### Mean +- std dev: 13.6 ms +- 0.2 msProbably because the new code does not create an iterator from the list and PyList_GET_ITEM is a bit faster than PyIter_Next (extra incref/decref)?
- added a commit that references this issue
on Aug 6, 2022 It caused a regression for OrderedDict. See #100272.
JSON encoder can produce output sorted by key (
json.dumps(sort_keys=True)) The default value forsort_keysisFalse. The code always creates a list of dictionary items, sorts them if needed, and then iterates through them.However, if sorting is not requested we can use
PyDict_Nextto avoid allocating a list of tuples.pyperformance on my machine before changes:
pyperformance after changes: