[Python-checkins] bpo-33234: Add exact allocation optimization to lists in What's New (GH-10200)
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Sun Oct 28 18:03:23 EDT 2018
author: Pablo Galindo <Pablogsal at gmail.com>
committer: GitHub <noreply at github.com>
bpo-33234: Add exact allocation optimization to lists in What's New (GH-10200)
In commit 372d705 a new optimization to the list() type was introduced but it was not added
to the optimization section in What's new for Python 3.8.
diff --git a/Doc/whatsnew/3.8.rst b/Doc/whatsnew/3.8.rst
index 05b7d235cee8..758d32e6e55a 100644
@@ -242,6 +242,11 @@ Optimizations
Note that this means that instances can no longer be weak-referenced and
that arbitrary attributes can no longer be added to them.
+* The :class:`list` constructor does not overallocate the internal item buffer
+ if the input iterable has a known length (the input implements ``__len__``).
+ This makes the created list 12% smaller on average. (Contributed by Pablo
+ Galindo in :issue:`33234`.)
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