From 9df2b6ccc719b0bc0167da65b72b57f9da39398b Mon Sep 17 00:00:00 2001 From: Omkar Kabde Date: Sat, 23 May 2026 02:32:56 +0530 Subject: [PATCH] gh-82907: Document mtime=0 for reproducible tarfile gzip output (GH-150269) --- Doc/library/tarfile.rst | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/Doc/library/tarfile.rst b/Doc/library/tarfile.rst index 6f1e01cf5aa..9b9783d8e58 100644 --- a/Doc/library/tarfile.rst +++ b/Doc/library/tarfile.rst @@ -144,7 +144,9 @@ Some facts and figures: For modes ``'w:gz'`` and ``'w|gz'``, :func:`tarfile.open` accepts the keyword argument *mtime* to create a gzip archive header with that mtime. By - default, the mtime is set to the time of creation of the archive. + default, the mtime is set to the time of creation of the archive. Use + *mtime* ``0`` to generate a compressed stream that does not depend on + creation time, for reproducible output. For special purposes, there is a second format for *mode*: ``'filemode|[compression]'``. :func:`tarfile.open` will return a :class:`TarFile`