diff options
| author | Mark Dickinson <mdickinson@enthought.com> | 2021-06-15 19:13:10 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2021-06-15 19:13:10 (GMT) |
| commit | 8d0b2ca493e236fcad8709a622c1ac8ad29c372d (patch) | |
| tree | c2479efa4f03ceb9f97434477e19f32d11f25f95 /Doc | |
| parent | f6cf38c8e2240c6dd94664d8dffd8ff42cacbc42 (diff) | |
| download | cpython-8d0b2ca493e236fcad8709a622c1ac8ad29c372d.zip cpython-8d0b2ca493e236fcad8709a622c1ac8ad29c372d.tar.gz cpython-8d0b2ca493e236fcad8709a622c1ac8ad29c372d.tar.bz2 | |
[3.10] bpo-43475: Add what's new entry for NaN hash changes (GH-26725) (GH-26743)
(cherry picked from commit 1d10bf0bb9409a406c56b0de8870df998637fd0f)
Co-authored-by: Mark Dickinson <mdickinson@enthought.com>
Diffstat (limited to 'Doc')
| -rw-r--r-- | Doc/whatsnew/3.10.rst | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/Doc/whatsnew/3.10.rst b/Doc/whatsnew/3.10.rst index 530ffce..6bd4157 100644 --- a/Doc/whatsnew/3.10.rst +++ b/Doc/whatsnew/3.10.rst @@ -836,6 +836,13 @@ Other Language Changes effectless under ``from __future__ import annotations``. (Contributed by Batuhan Taskaya in :issue:`42725`.) +* Hashes of NaN values of both :class:`float` type and + :class:`decimal.Decimal` type now depend on object identity. Formerly, they + always hashed to ``0`` even though NaN values are not equal to one another. + This caused potentially quadratic runtime behavior due to excessive hash + collisions when creating dictionaries and sets containing multiple NaNs. + (Contributed by Raymond Hettinger in :issue:`43475`.) + New Modules =========== |