languages/cpython
languages/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython synced 2024-07-21 02:05:18 +00:00
Code Issues Actions 7 Packages Projects Releases Wiki Activity

[3.12] gh-112346: Document the OS byte in gzip.compress output change in 3.11 (GH-120480) (#120613)

Browse source 
gh-112346: Document the OS byte in `gzip.compress` output change in 3.11 (GH-120480)
(cherry picked from commit bac4edad69)


gh-112346: Describe the "os" byte in gzip output change.

Co-authored-by: Gregory P. Smith <greg@krypto.org>
This commit is contained in:
Miss Islington (bot) 2024-06-17 07:54:33 +02:00 committed by GitHub
parent 717d2bd1d9
commit 40ce124886
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
2 changed files with 18 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
Doc/library/gzip.rst
View file

@ -194,7 +194,9 @@ The module defines the following items:
.. versionchanged:: 3.11
Speed is improved by compressing all data at once instead of in a
streamed fashion. Calls with *mtime* set to ``0`` are delegated to
:func:`zlib.compress` for better speed.
:func:`zlib.compress` for better speed. In this situation the
output may contain a gzip header "OS" byte value other than 255
"unknown" as supplied by the underlying zlib implementation.
.. function:: decompress(data)

15
Doc/whatsnew/3.11.rst
View file

@ -768,6 +768,21 @@ functools
(Contributed by Yurii Karabas in :issue:`46014`.)
.. _whatsnew311-gzip:
gzip
----
* The :func:`gzip.compress` function is now faster when used with the
**mtime=0** argument as it delegates the compression entirely to a single
:func:`zlib.compress` operation. There is one side effect of this change: The
gzip file header contains an "OS" byte in its header. That was traditionally
always set to a value of 255 representing "unknown" by the :mod:`gzip`
module. Now, when using :func:`~gzip.compress` with **mtime=0**, it may be
set to a different value by the underlying zlib C library Python was linked
against.
(See :gh:`112346` for details on the side effect.)
.. _whatsnew311-hashlib:
hashlib