Making a Python release is a thrilling and crazy process. You've heard
the expression "herding cats"? Imagine trying to also saddle those
purring little creatures up, and ride them into town, with some of their
buddies firmly attached to your bare back, anchored by newly sharpened
claws. At least they're cute, you remind yourself.
Actually, no that's a slight exaggeration <wink>. The Python release
process has steadily improved over the years and now, with the help of our
amazing community, is really not too difficult. This PEP attempts to
collect, in one place, all the steps needed to make a Python release. It
is organized as a recipe and you can actually print this out and check
items off as you complete them.
How to Make A Release
Here are the steps taken to make a Python release. Some steps are more
fuzzy than others because there's little that can be automated (e.g.
writing the NEWS entries). Where a step is usually performed by An
Expert, the role of that expert is given. Otherwise, assume the step is
done by the Release Manager (RM), the designated person performing the
release. The roles and their current experts are:
* RM = Release Manager: Georg Brandl <email@example.com> (Central Europe)
* WE = Windows: Martin von Loewis <firstname.lastname@example.org> (Central Europe)
* ME = Mac: Ned Deily <email@example.com> (US)
* DE = Docs: Georg Brandl <firstname.lastname@example.org> (Central Europe)
* IE = Idle Expert: ??
NOTE: It is highly recommended that the RM contact the Experts the day
before the release. Because the world is round and everyone lives
in different timezones, the RM must ensure that the release tag is
created in enough time for the Experts to cut binary releases.
IT IS HIGHLY RECOMMENDED THAT YOU AT LEAST TAG THE TREE 24 HOURS
BEFORE A FINAL RELEASE. This will give the Experts enough time to
do their bits before the announcement goes out.
In any case, the RM MUST wait for the "green light" from the
following experts before updating the web pages and sending the
announcement: WE, DE
XXX: We should include a dependency graph to illustrate the steps that can
be taken in parallel, or those that depend on other steps.
As much as possible, the release steps are automated and guided by the
release script, which is available in a separate repository:
We use the following conventions in the examples below. Where a release
number is given, it is of the form X.Y.ZaN, e.g. 3.3.0a3 for Python 3.3.0
alpha 3, where "a" == alpha, "b" == beta, "rc" == release candidate.
Release tags are named "vX.Y.ZaN". The branch name for minor release
maintenance branches is "X.Y".
This helps by performing several automatic editing steps, and guides you
to perform some manual editing steps.
___ Log into irc.freenode.net and join the #python-dev channel.
You probably need to coordinate with other people around the world.
This IRC channel is where we've arranged to meet.
___ Check to see if there are any showstopper bugs.
Go to http://bugs.python.org and look for any open bugs that can block
this release. You're looking at the Priority of the open bugs for the
release you're making; here are the relevant definitions:
release blocker - Stops the release dead in its tracks. You may not
make any release with any open release blocker bugs.
deferred blocker - Doesn't block this release, but it will block a
future release. You may not make a final or
candidate release with any open deferred blocker
critical - Important bugs that should be fixed, but which does not block
Review the release blockers and either resolve them, bump them down to
deferred, or stop the release and ask for community assistance. If
you're making a final or candidate release, do the same with any open
___ Check the stable buildbots.
Go to http://www.python.org/dev/buildbot/stable/
(the trailing slash is required). Look at the buildbots for the release
you're making. Ignore any that are offline (or inform the community so
they can be restarted). If what remains are (mostly) green buildbots,
you're good to go. If you have non-offline red buildbots, you may want
to hold up the release until they are fixed. Review the problems and
use your judgement, taking into account whether you are making an alpha,
beta, or final release.
___ Make a release clone.
Create a local clone of the cpython repository (called the "release
clone" from now on).
Also clone the repo at http://hg.python.org/cpython using the
server-side clone feature. The name of the new clone should preferably
have a "releasing/" prefix. The other experts will use the release
clone for making the binaries, so it is important that they have access
Optionally, set up your local release clone to push to the remote
release clone by default (by editing .hg/hgrc to that effect).
___ Notify all committers by sending email to email@example.com.
Since we're now working with a distributed version control system, there
is no need to stop everyone from pushing to the main repo; you'll just
work in your own clone. Therefore, there won't be any checkin freezes.
However, all committers should know the point at which your release
clone was made, as later commits won't make it into the release without
___ Make sure the current branch of your release clone is the branch you
want to release from.
___ Regenerate Lib/pydoc-topics.py.
cd to the Doc directory and type ``make pydoc-topics``. Then copy
``build/pydoc-topics/pydoc-topics.py`` to ``../Lib/pydoc_topics.py``.
___ Check the docs for markup errors.
In the Doc directory, type ``make suspicious``. If any markup errors
are found, fix them.
___ Commit any changes to pydoc_topics.py and the doc sources.
___ Make sure the SOURCE_URI in ``Doc/tools/sphinxext/pyspecific.py``
points to the right branch in the hg repository (or ``default`` for
unstable releases of the default branch).
___ Bump version numbers via the release script.
$ .../release/release.py --bump X.Y.ZaN
This automates updating various release numbers, but you will have to
modify a few files manually. If your $EDITOR environment variable is
set up correctly, release.py will pop up editor windows with the files
you need to edit.
It is important to update the Misc/NEWS file, however in recent years,
this has become easier as the community is responsible for most of the
content of this file. You should only need to review the text for
sanity, and update the release date with today's date.
Commit the changes once you have reviewed them.
___ Check the years on the copyright notice. If the last release
was some time last year, add the current year to the copyright
notice in several places:
___ LICENSE (make sure to change on trunk and the branch)
___ Doc/README.txt (at the end)
___ PC/python_nt.rc sets up the DLL version resource for Windows
(displayed when you right-click on the DLL and select
___ The license.ht file for the distribution on the website
contains what purports to be an HTML-ized copy of the LICENSE
file from the distribution. You'll need to bump the version number to
the one you're releasing. BROKEN
___ Check with the IE (if there is one <wink>) to be sure that
Lib/idlelib/NEWS.txt has been similarly updated.
___ For a final major release, edit the first paragraph of
Doc/whatsnew/X.Y.rst to include the actual release date; e.g. "Python
2.5 was released on August 1, 2003." There's no need to edit this for
alpha or beta releases. Note that Andrew Kuchling often takes care of
___ Tag the release for X.Y.ZaN.
$ .../release/release.py --tag X.Y.ZaN
NOTE: when forward, i.e. "null" merging your changes to newer branches,
e.g. 2.6 -> 2.7, do *not* revert your changes to the .hgtags file or you
will not be able to run the --export command below. Revert everything
else but leave .hgtags alone.
___ If this is a final major release, branch the tree for X.Y.
When making a major release (e.g., for 3.2), you must create the
long-lived maintenance branch.
___ Note down the current revision ID of the tree.
$ hg identify
___ First, set the original trunk up to be the next release.
$ .../release/release.py --bump 3.3a0
___ Edit all version references in the README
___ Move any historical "what's new" entries from Misc/NEWS to
___ The LICENSE file. Add the pending version to the list of
releases, and be sure to check the release dates.
___ There's a copy of the license in Doc/license.rst.
___ Doc/tutorial/interpreter.rst (2 references to '[Pp]ython32', one
to 'Python 3.2').
___ Doc/tutorial/stdlib.rst and Doc/tutorial/stdlib2.rst, which have
each one reference to '[Pp]ython32'.
___ Update the version number in configure.ac and re-run autoconf.
___ Update the version numbers for the Windows builds in PC/ and
PCbuild/, which have references to python32.
$ find PC/ PCbuild/ -type f | xargs sed -i 's/python32/python33/g'
$ hg mv -f PC/os2emx/python32.def PC/os2emx/python33.def
$ hg mv -f PC/python32stub.def PC/python33stub.def
$ hg mv -f PC/python32gen.py PC/python33gen.py
___ Commit these changes to the default branch.
___ Now, go back to the previously noted revision and make the
maintenance branch *from there*.
$ hg update deadbeef # revision ID noted down before
$ hg branch 3.2
___ Push your commits to the remote release clone.
$ hg push ssh://hg.python.org/releasing/...
___ Notify the experts that they can start building binaries.
___ STOP STOP STOP STOP STOP STOP STOP STOP
At this point you must receive the "green light" from other experts in
order to create the release. There are things you can do while you wait
though, so keep reading until you hit the next STOP.
___ XXX The WE builds the Windows helpfile, using (in Doc/) either
$ make htmlhelp (on Unix)
> make.bat htmlhelp (on Windows)
to create suitable input for HTML Help Workshop in build/htmlhelp. HTML
Help Workshop is then fired up on the created python26.hhp file, finally
resulting in an python26.chm file. He then copies the file into the Doc
directories of the build trees (once for each target architecture).
XXX The CHM file should also be scp'd to the docs download location.
___ XXX The WE then generates Windows installer files for each Windows
target architecture (for Python 2.6, this means x86 and AMD64). He has
one checkout tree per target architecture, and builds the pcbuild.sln
project for the appropriate architecture. He then edits
Tools/msi/config.py to update full_current_version, sets snapshot to
False and runs msi.py with ActivePython 2.5 or Python 2.5 with pywin32.
For that to work, the following prerequisites must be met:
- PC\icons.mak must have been run with nmake.
- The cmd.exe window in which this is run must have Cygwin/bin in its
path (atleast for x86).
- The cmd.exe window must have MS compiler tools for the target
architecture in its path (VS 2003 for x86, the platform SDK for
- The cmd.exe window must also have cabarc.exe from the CAB SDK in its
The WE checksums the files (*.msi and *.chm), uploads them to some place
in the net, and emails you the location and md5sums.
___ Time to build the source tarball. Be sure to update your clone to the
correct branch. E.g.
$ hg update 3.2
___ Do a "hg status" in this directory.
You should not see any files. I.e. you better not have any uncommitted
changes in your working directory.
___ Use the release script to create the source gzip and bz2 tarballs, md5
checksums, documentation tar and zip files, and gpg signature files.
$ .../release/release.py --export X.Y.ZaN
This will leave all the relevant files in a subdirectory called
'X.Y.ZaN/src', and the built docs in 'X.Y.ZaN/docs' (for final releases).
___ scp or rsync all the files to your home directory on dinsdale.python.org.
While you're waiting for the files to finish uploading, you can continue
on with the remaining tasks. You can also ask folks on #python-dev
and/or python-committers to download the files as they finish uploading
so that they can test them on their platforms as well.
___ Now you want to perform the very important step of checking the
tarball you just created, to make sure a completely clean,
virgin build passes the regression test. Here are the best
steps to take:
$ cd /tmp
$ tar xvf ~/Python-3.2rc2.tgz
$ cd Python-3.2rc2
(Do things look reasonable?)
$ ls Lib
(Are there stray .pyc files?)
$ ls Doc/tools
(Make sure it doesn't contain "docutils", "sphinx", "jinja" or
"pygments" directories. Also look for stray .pyc files.)
(Loads of configure output)
$ make test
(Do all the expected tests pass?)
If you're feeling lucky and have some time to kill, or if you are making
a release candidate or final release, run the full test suite:
$ make TESTOPTS='-u all' test
If the tests pass, then you can feel good that the tarball is
fine. If some of the tests fail, or anything else about the
freshly unpacked directory looks weird, you better stop now and
figure out what the problem is.
___ Now you need to go to dinsdale.python.org and move all the files in
place over there. Our policy is that every Python version gets its own
directory, but each directory may contain several releases. We keep all
old releases, moving them into a "prev" subdirectory when we have a new
So, there's a directory called "3.2" which contains Python-3.2.msi and
Python-3.2.tgz, along with a "prev" subdirectory containing
Python-3.2a1.msi, Python-3.2a1.tgz, Python-3.2a1.tar.bz2, etc.
___ On dinsdale, cd /data/ftp.python.org/pub/python/X.Y.Z
creating it if necessary. Make sure it is owned by group 'webmaster'
___ Move the previous release files to a directory called 'prev'
creating the directory if necessary (make sure the directory has
g+ws bits on). If this is the first alpha release of a new Python
version, skip this step.
For pre-releases (alpha, beta, rc), don't move things into a 'prev'
directory, You'll move everything in there when the final release
___ Move the release .tgz, tar.bz2, and .msi files into place, as well
as the .asc GPG signature files.
Make sure they are world readable. They should also be group
writable, and group-owned by webmaster.
___ md5sum the files and make sure they got uploaded intact.
___ If this is a final release: Move the doc zips and tarballs to
/data/ftp.python.org/pub/python/doc/X.Y.Z creating the directory
if necessary, and adapt the "current" symlink in .../doc to point to
that directory. Note though that if you're releasing a maintenance
release for an older version, don't change the current link.
___ If this is a final release (even a maintenance release), also unpack
the HTML docs to
If it is a release of a security-fix-only version, tell the DE to
build a version with the "version switcher" and put it there.
___ Let the DE check if the docs are built and work all right.
___ If this is a major release: Tell the DE to adapt redirects for
docs.python.org/X.Y in the Apache config for docs.python.org, update
the script Doc/tools/dailybuild.py to point to the right
stable/development branches, and to install it and make the initial
checkout. The Doc's version_switcher.js script also needs to be
___ For the extra paranoid, do a completely clean test of the
release. This includes downloading the tarball from
Make sure the md5 checksums match. Then unpack the tarball,
and do a clean make test.
$ make distclean
$ make test
To ensure that the regression test suite passes. If not, you
screwed up somewhere!
Now it's time to twiddle the web site.
To do these steps, you must have the permission to edit the website. If you
don't have that, ask someone on firstname.lastname@example.org for the proper
permissions. It's insane for you not to have it.
I'm not going to go into the details of building the site or pushing it
live. Plenty of people on pydotorg can help you, and there's a good README
once you get the branch. All the directories below are named relative to
the data subdirectory unless otherwise noted.
This page will probably come in handy:
None of the web site updates are automated by release.py.
___ Build the basic site.
In the top directory, do an `svn update` to get the latest code. In the
build subdirectory, do `make` to build the site. Do `make serve` to
start service the pages on localhost:8005. Hit that url to see the site
as it is right now. At any time you can re-run `make` to update the
local site. You don't have to restart the server.
Don't `svn commit` until you're all done!
___ If this is the first release for this version (even a new patch
version), you'll need to create a subdirectory inside download/releases
to hold the new version files. It's probably a good idea to copy an
existing recent directory and twiddle the files in there for the new
___ Add a news section item to the front page by editing newsindex.yml. The
format should be pretty self evident.
___ If this is a final release...
___ update the 'Quick Links' section on the front page. Edit the
top-level `content.ht` file.
___ update the download page, editing `download/content.ht`
___ edit the previous release's last release content.ht page to point to
the new release.
___ update `doc/content.ht` to indicate the new current documentation
version, and remove the current version from any 'in development'
section. Update the version in the "What's New" link.
___ Add the new version to `doc/versions/content.ht`.
___ Edit download/releases/content.ht to update the version numbers for
this release. There are a bunch of places you need to touch:
___ The subdirectory name as the first element in the Nav rows.
___ Possibly the Releases section, and possibly in the experimental
releases section if this is an alpha, beta or release candidate.
___ Update the version specific pages.
___ cd to download/releases/X.Y.Z
___ Edit the version numbers in content.ht
___ Comment out the link to the CHM file if this is not a final,
remove the comment if it is.
___ Update the md5 checksums
Note, you don't have to copy the actual .tgz or tar.bz2 tarballs into
this directory because they only live on dinsdale in the ftp directory.
___ When everything looks good, `svn commit` in the data directory. This
will trigger the live site to update itself, and at that point the
release is live.
___ If this is a final release, create a new python.org/X.Y Apache alias
(or ask pydotorg to do so for you).
Now it's time to write the announcement for the mailing lists. This is the
fuzzy bit because not much can be automated. You can use an earlier
announcement as a template, but edit it for content!
___ STOP STOP STOP STOP STOP STOP STOP STOP
___ Have you gotten the green light from the WE?
___ Have you gotten the green light from the DE?
___ Once the announcement is ready, send it to the following
Now it's time to do some cleaning up. These steps are very important!
___ Do the guided post-release steps with the release script.
$ .../release/release.py --done X.Y.ZaN
Review and commit these changes.
___ Merge your release clone into the main development repo:
$ cd ../cpython # your clone of the main repo
$ hg pull ssh://hg.python.org/cpython # update from remote first
$ hg pull ../cpython-releaseX.Y # now pull from release clone
Now merge your release clone's changes in every branch you touched
(usually only one, except if you made a new maintenance release).
Easily resolvable conflicts may appear in Misc/NEWS.
Commit and push to the main repo.
___ You can delete the remote release clone, or simply reuse it for the next
___ Send email to python-committers informing them that the release has been
___ Update any release PEPs (e.g. 361) with the release dates.
___ Update the tracker at http://bugs.python.org:
___ Flip all the deferred blocker issues back to release blocker
for the next release.
___ Add version X.Y+1 as when version X.Y enters alpha.
___ Change non-doc RFEs to version X.Y+1 when version X.Y enters beta.
___ Update 'behavior' issues from versions that your release make
unsupported to the next supported version.
___ Review open issues, as this might find lurking showstopper bugs,
besides reminding people to fix the easy ones they forgot about.
___ Verify! Pretend you're a user: download the files from python.org, and
make Python from it. This step is too easy to overlook, and on several
occasions we've had useless release files. Once a general server problem
caused mysterious corruption of all files; once the source tarball got
built incorrectly; more than once the file upload process on SF truncated
files; and so on.
___ Rejoice. Drink. Be Merry. Write a PEP like this one. Or be
like unto Guido and take A Vacation.
You've just made a Python release!
Windows has a MSI installer, various flavors of Windows have
"special limitations", and the Windows installer also packs
precompiled "foreign" binaries (Tcl/Tk, expat, etc). So Windows
testing is tiresome but very necessary.
Concurrent with uploading the installer, the WE installs Python
from it twice: once into the default directory suggested by the
installer, and later into a directory with embedded spaces in its
name. For each installation, he runs the full regression suite
from a DOS box, and both with and without -0. For maintenance
release, he also tests whether upgrade installations succeed.
He also tries *every* shortcut created under Start -> Menu -> the
Python group. When trying IDLE this way, you need to verify that
Help -> Python Documentation works. When trying pydoc this way
(the "Module Docs" Start menu entry), make sure the "Start
Browser" button works, and make sure you can search for a random
module (like "random" <wink>) and then that the "go to selected"
It's amazing how much can go wrong here -- and even more amazing
how often last-second checkins break one of these things. If
you're "the Windows geek", keep in mind that you're likely the
only person routinely testing on Windows, and that Windows is
simply a mess.
Repeat the testing for each target architecture. Try both an
Admin and a plain User (not Power User) account.
This document has been placed in the public domain.