Issue 32385: Clean up the C3 MRO algorithm implementation. (original) (raw)

Issue32385

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This issue has been migrated to GitHub: https://github.com/python/cpython/issues/76566

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Created on 2017-12-20 15:40 by serhiy.storchaka, last changed 2022-04-11 14:58 by admin. This issue is now closed.

Messages (3)
msg308739 - (view)	Author: Serhiy Storchaka (serhiy.storchaka) *	Date: 2017-12-20 15:40
The C3 MRO algorithm implementation uses lists and converts input tuples to lists. This is redundant, because these lists are not mutated. The proposed PR makes the implementation using tuples and gets rid of unneeded conversions.
msg308751 - (view)	Author: Serhiy Storchaka (serhiy.storchaka) *	Date: 2017-12-20 17:18
This has also a performance effect. $ ./python -m perf timeit -s "class A: pass" -s "class B: pass" --duplicate 1000 "class C(A, B): pass" Before: Mean +- std dev: 9.41 us +- 0.28 us After: Mean +- std dev: 8.94 us +- 0.28 us
msg308752 - (view)	Author: Serhiy Storchaka (serhiy.storchaka) *	Date: 2017-12-20 17:21
New changeset 6b91a5972107ec8dd5334f4f2005626baa2b8847 by Serhiy Storchaka in branch 'master': bpo-32385: Clean up the C3 MRO algorithm implementation. (#4942) https://github.com/python/cpython/commit/6b91a5972107ec8dd5334f4f2005626baa2b8847