New submission from Sergey B Kirpichev <skirpic...@gmail.com>:
The current version of the Fraction.__reduce__() method uses str(), which produces bigger dumps, esp. for large components. C.f.: >>> import random, pickle >>> from fractions import Fraction as F >>> random.seed(1); a = F(*random.random().as_integer_ratio()) >>> for proto in range(pickle.HIGHEST_PROTOCOL + 1): ... print(len(pickle.dumps(a, proto))) ... 71 70 71 71 77 77 >>> b = a**13 >>> for proto in range(pickle.HIGHEST_PROTOCOL + 1): ... print(len(pickle.dumps(b, proto))) ... 444 443 444 444 453 453 vs the attached patch: >>> for proto in range(pickle.HIGHEST_PROTOCOL + 1): ... print(len(pickle.dumps(a, proto))) ... 71 68 49 49 59 59 >>> for proto in range(pickle.HIGHEST_PROTOCOL + 1): ... print(len(pickle.dumps(b, proto))) ... 444 441 204 204 214 214 Testing for non-default protocols was also added. Let me know if all this does make sense as a PR. ---------- components: Library (Lib) files: fractions-pickle.diff keywords: patch messages: 393781 nosy: Sergey.Kirpichev priority: normal severity: normal status: open title: Optimize Fraction pickling versions: Python 3.11 Added file: https://bugs.python.org/file50047/fractions-pickle.diff _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue44154> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
