PEP: 101
Title: Doing Python Releases 101
Version: $Revision: 2144 $
Last-Modified: $Date: 2005-09-27 21:21:36 -0700 (Tue, 27 Sep 2005) $
Author: Barry A. Warsaw <barry at>, Guido van Rossum <guido at>
Status: Active
Type: Informational
Created: 22-Aug-2001


    Making a Python release is an arduous process that takes a
    minimum of half a day's work even for an experienced releaser.
    Until recently, most -- if not all -- of that burden was borne by
    Guido himself.  But several recent releases have been performed by
    other folks, so 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 name of that expert is given.
    Otherwise, assume the step is done by the Release Manager (RM),
    the designated person performing the release.  Almost every place
    the RM is mentioned below, this step can also be done by the BDFL
    of course!

    XXX: We should include a dependency graph to illustrate the steps
    that can be taken in parallel, or those that depend on other

    We use the following conventions in the examples below.  Where a
    release number is given, it is of the form X.YaZ, e.g. 2.1a3 for
    Python 2.1 alpha 3, where "a" == alpha, "b" == beta, "rc" ==
    release candidate.

    Final releases are named "releaseXY".  The branch tag is
    "releaseXY-maint" because this will point to the long lived
    maintenance branch.  The fork tag on the trunk is
    "releaseXY-fork".  If a micro release number is used, then we'll
    say X.Y.MaZ.

    Note: This document has been updated to reflect the more
    streamlined procedures used to release Python 2.3 (including the
    alphas and betas).

  ___ Impose a check-in freeze.  Send a message to telling people not to make any check-ins
      on the tree until further notice.

      At this point, nobody except the RM should make any commits to
      the branch (or his duly assigned agents, i.e. Guido the BDFL,
      Fred Drake for documentation, or Tim Peters for Windows).  If
      the RM screwed up and some desperate last minute change to the
      branch is necessary, it can mean extra work for Fred and Tim.
      So try to avoid this!

  ___ Log into 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.

  ___ The most important thing to do is to update the Misc/NEWS file.
      Tim will need this in order to do the Windows release and he
      likes to stay up late.  This step can be pretty tedious, so it's
      best to get to it immediately after making the branch, or even
      before you've made the branch.

      Add high level items new to this release.  E.g. if we're
      releasing 2.2a3, there must be a section at the top of the file
      explaining "What's new in Python 2.2a3".  It will be followed by
      a section entitled "What's new in Python 2.2a2".

      Note that you /hope/ that as developers add new features to the
      trunk, they've updated the NEWS file accordingly.  You can't be
      positive, so double check.  If you're a Unix weenie, it helps to
      verify with Tim Peters about changes on Windows, and Jack Jansen
      about changes on the Mac.

      This command should help you:

      % cvs log | python Tools/scripts/ > /tmp/news.txt

      IOW, you're printing out all the cvs log entries from the
      previous release until now.  You can then troll through the
      news.txt file looking for interesting things to add to NEWS.

  ___ For major releases (e.g. 2.3 final), move any historical "what's
      new" entries from Misc/NEWS to Misc/HISTORY.

  ___ Check with the IDLE maintainer to be sure that
      Lib/idlelib/NEWS.txt has been similarly updated.

  ___ For final (non-alpha/beta/candidate) releases, make sure the
      release date is fully spelled out in Doc/commontex/boilerplate.tex.

  ___ Tag and/or branch the tree for release X.YaZ

      If you're releasing an alpha/beta/release candidate, you will
      just tag the tree.  If you are releasing a final release, you
      will both tag the trunk and create the long-lived maintenance

      All Python development happens on the trunk.  While it's
      sometimes challenging to keep people from checking things in
      while you're making a release, it's still preferred to creating
      a short-lived release branch.

      Practically speaking, we tag and branch just before making the
      release.  Tagging too early causes too much merging work.

    ___ Do a CVS update with the -A, -d, and -P flags, e.g.
        % cvs -q update -d -P -A

      To tag the tree, do the following:

    ___ cvs tag rXYaZ

      To create a maintenance branch the following steps are taken:

    ___ CVS tag the trunk with the symbolic name "releaseXY-fork", e.g.
        % cvs tag releaseXY-fork

    ___ Make the branch with the symbolic name "releaseXY-maint", e.g.
        % cvs tag -b releaseXY-maint

    ___ Check out a clean version of the branch into a new directory.
        You'll be doing a lot of work in this directory and you want
        to keep it straight from your trunk working directory.  E.g.

        % export
        % cvs -q co -d python-22a3 -r release23-maint python/dist/src

    ___ cd into the branch directory.

  ___ Change Include/patchlevel.h in two places, to
      reflect the new version number you've just created.  You'll want
      to change the PY_VERSION macro, and one or several of the
      version subpart macros just above PY_VERSION, as appropriate.

  ___ IDLE maintains its own versioning and NEWS file (Lib/idlelib/NEWS.txt).
      There should be a number of entries reflecting new development, under a
      temporary header.  Update that header to reflect IDLE's new version and
      release date.  Then update Lib/idlelib/ to show a matching

  ___ Change the "%define version" line of Misc/RPM/python-2.3.spec to
      the same string as PY_VERSION was changed to above.  E.g.

       %define version 2.3.1

       The following line, "%define libvers", should reflect the
       major/minor number as one would usually see in the
       "/usr/lib/python<libvers>" directory name.  E.g.

       %define libvers 2.3

       You also probably want to reset the %define release line
       to '1pydotorg' if it's not already that.

       If the new release uses a major/minor version which is
       different than is in the name of the current
       "Misc/RPM/python-*.spec" file, rename the file:

       % mv python-2.3.spec python-2.4.spec
       % cvs remove python-2.3.spec
       % cvs add python-2.4.spec
       % cvs commit

  ___ If this is a release candidate, mail Sean <>
      noting the impending release, so that RPMs can be built and

  ___ Update the README file, which has a big banner at the top
      proclaiming its identity.

  ___ If the major (first) or minor (middle) digit of the version
      number changes, also update the LICENSE file.

    ___ There's a copy of the license in
        Doc/commontex/license.tex; Fred usually takes care of that.

  ___ 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:

    ___ README

    ___ LICENSE

    ___ Python/getcopyright.c

    ___ Doc/commontex/copyright.tex

    ___ PC/python_nt.rc sets up the DLL version resource for Windows
        (displayed when you right-click on the DLL and select

    ___ PCbuld/python20.wse sets up the Windows installer version
        resource (displayed when you right-click on the installer .exe
        and select Properties).

    ___ The file for the distribution on the website
        contains what purports to be an HTML-ized copy of the LICENSE
        file from the distribution.

  ___ For a final release, edit the first paragraph of
      Doc/whatsnew/whatsnewXX.tex to include the actual release date;
      e.g. "Python 2.3 was released on August 1, 2003."
      There's no need to edit this for alpha or beta releases.  Note
      that Andrew often takes care of this.

  ___ At this point, Fred will create the formatted versions of the
      documentation and push the appropriate files out to their FTP
      locations on  The HTML format is used to build
      the HTML Help format for the Windows installer, but the RM
      doesn't need this to build the source distribution.  The HTML
      Help format will typically be generated by whoever builds the
      Windows installer.

      Once Fred is done, there can be no further checkins on the
      branch in the Doc/ directory -- not even by the RM.

      Building the documentation is done using the Makefile in the
      Doc/ directory.  Once all the external tools are installed (see
      the "Documenting Python" manual for information on the required
      tools), use these commands to build the formatted documentation

        $ make clobber
        $ make PAPER=a4 paperdist
        $ make distfiles

      The packages can be installed on the FTP server using commands
      like these:

        $ VERSION=`tools/getversioninfo`
        $ TARGET=/ftp/$VERSION
        $ ssh mkdir $TARGET
        $ scp *-$VERSION.*$TARGET

  ___ For final releases, publish the documentation on
      This must be done by someone with write access to the
      CVS repository.

      Start by creating a new directory and filling it with the
      standard boilerplate.  $VERSION is the same as for uploading the
      documentation, above; $OLDVERSION is the most recently published
      version on the site.

        $ cd .../pydotorg/doc/
        $ mkdir $VERSION
        $ cvs add $VERSION
        $ cd $OLDVERSION
        $ cp .cvsignore Makefile ../$VERSION
        $ cd ../$VERSION
        $ cvs add .cvsignore Makefile *.ht

      Now make the following edits:

      - in Makefile, change the value of ROOT_OFFSET to doc/$VERSION

      - in, change:
        - the version number to $VERSION in two places: the Title:
          header, and the <h3> at the top of the page
        - the release date, in the <h3> at the top of the page
        - if the minor release number changed (for example, from 2.3
          to 2.4), the title and link to the "What's New" document
          (search for "whatsnew")

      - in, change:
        - the version number to $VERSION in two places: the Title:
          header, and the <h3> at the top of the page
        - the release date, in the <h3> at the top of the page
        - if the minor release number changed (for example, from 2.3
          to 2.4), the title and link to the "What's New" document
          (search for "whatsnew")
        - replace the large table of downloads with the content of the
          pkglist.html file generated by the documentation build

      Now, the web content has all been prepared, but there's still
      some dancing to do to make it all work right.  To be safe, we
      can commit the new files to CVS, but we're *not* ready to
      install them on the site yet:

        $ cvs commit -m \
          "Add website content for Python $VERSION documentation."

      Log into using SSH and unpack a copy of the
      documentation into place:

        # on creosote:
        $ cd /ftp/
        $ tar xjf \
        $ mv Python-Docs-$VERSION $VERSION
        $ find $VERSION -type d | xargs chmod g+s

      Now head back to your pydotorg checkout on your workstation, and
      push website content into place:

        $ cd .../pydotorg/doc/$VERSION
        $ make install

      Point your browser at this URL and check it out:$VERSION/

      There are three more changes that need to happen in the
      top-level doc/ directory of the website content.  The first of
      these can happen any time after what's already happened in this
      process, and the last two should happen as soon as the release
      announcement has been made.  Those are described in a separate
      step of this checklist.

      At this time, edit the file in doc/ to make add the
      new release at the top.  The previous latest release should drop
      down to the top of the long list of released versions, and the
      new release should replace the previous most recent release.
      There should be a blank line between the link to the development
      documentation and the most recent release, and another blank
      line between the most recent release and the long list of older
      releases.  (Is should be fairly easy to figure this out while
      looking at the file.)

  ___ Thomas grabs the HTML to build the Windows helpfile.
      The HTML files are unpacked into a new src/html directory, and
      runs this command to create the project files for MS HTML

      % python ..\Doc\tools\ -v 2.3 python23

      HTML Workshop is then fired up on the created python23.hhp file,
      finally resulting in an python23.chm file.

  ___ Tim Peters grabs the HTML Help format and uses this to build the
      Windows installer.

  ___ Tim performs his Windows magic, generating an installer
      executable.  He uploads this file to SourceForge, and then sends
      the RM a notice which includes the location and MD5 checksum of
      the Windows executable.

      Note that Tim used to upload the installer to,
      but has had problems with ssh for a while now.

      Note that Tim's creation of the Windows executable may generate
      a few more commits on the branch.  Tim will be responsible for
      merging Windows-specific changes from trunk to branch, and from
      branch to trunk.

  ___ Sean Reifschneider grabs the HTML and uses this to build the
      Linux RPMs.  Sean performs his Red Hat magic, generating a set
      of RPMs.  He uploads these files to  He then sends
      the RM a notice which includes the location and MD5 checksum of
      the RPMs.

  ___ Download the Windows executable from SourceForge to  Tell Tim so he can remove the file from

  ___ Time to build the source tarball.  If you created a branch, be
      sure to cd to your working directory for the branch.  E.g.
      % cd .../python-22a3

  ___ Do a "cvs update" in this directory.  Do NOT include the -A flag
      if you're working on a branch, but do include it if you're
      working on the trunk.

      You should not see any "M" files, but you may see several "P" or
      "U" files.  I.e. you better not have any uncommitted changes in
      your working directory, but you may pick up some of Fred's or
      Tim's last minute changes.

  ___ If you've seen updates to existing files, update the cvs tag:

      % cvs tag -F r22a3

      If you created a maintenance branch and you've changed any files
      since you branched, tag the tree -- in the branch -- now with
      something like

      % cvs tag r23

      This is the tag you will use below.

  ___ Change to a neutral directory, i.e. one in which you can do a
      fresh, virgin, cvs export of the branch.  You will be creating a
      new directory at this location, to be named "Python-X.YaZ".  Do
      a CVS export of the tagged branch.

      % cd ~
      % export
      % cvs export -rr23c2 -d Python-2.3c2 python/dist/src

  ___ Generate the tarball.  Note that we're not using the `z' option
      on the tar command because 1) that's only supported by GNU tar
      as far as we know, and 2) we're going to max out the compression
      level, which isn't a supported option.

      % tar cf - Python-2.3c2 | gzip -9 > Python-2.3c2.tgz

  ___ Calculate the MD5 checksum of the tgz file you just created

      % md5sum Python-2.3c2.tgz

      Note that if you don't have the md5sum program, there is a
      Python replacement in the Tools/scripts/ file.

  ___ 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 zxvf ~/Python-2.3c2.tgz
      % cd Python-2.3c2
      % ls
      (Do things look reasonable?)
      % ./configure
      (Loads of configure output)
      % make test
      (Do all the expected tests pass?)

      If you're feeling lucky and have some time to kill, 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.

  ___ Upload the tgz file to using scp.

  ___ Tim has been having trouble uploading to creosote, so he will
      usually put the file on SF, giving you the file name and the md5
      checksum.  It's best to do a wget from creosote to SF, but
      calculating the URL can be not-fun.  You can usually get the URL
      from the file download page, if you start the download and then
      immediately cancel it.

  ___ While you're waiting, you can start twiddling the web pages to
      include the announcement.

    ___ If necessary, and if you have the right permissions (the sysadmins must set this up for you), check out the
        web site CVS tree by doing:

        % cvs -d :ext:<you> co pydotorg

    ___ In the web site CVS tree, cd to the X.Y
        subdirectory, and copy to  Be sure to
        do a "cvs update" first!

        % cd .../pydotorg
        % cvs -q up -P -d
        % cd 2.2
        % cp

    ___ Edit the file for content: usually you can globally replace
        X.Ya(Z-1) with X.YaZ.  However, you'll need to think about the
        "What's New?" section.

    ___ Copy the Misc/NEWS file to NEWS.txt in the X.Y directory for; this contains the "full scoop" of changes to
        Python since the previous release for this version of Python.

    ___ Also, update the MD5 checksums.

    ___ Preview the web page by doing a "make" -- NOT a "make install".
        View the page via a file: url.

    ___ Similarly, edit the ../ file, i.e. the home
        page.  In the Big Blue Announcement Block, move the paragraph
        for the new version up to the top and boldify the phrase
        "Python X.YaZ is out".  Edit for content, and preview as
        above.  Do NOT do a "make install" yet!

    ___ Also on the ../ file (still the home page),
        update the link information so that the release status is
        correct.  Update the links in the left-hand navigation
        sidebar.  Still do NOT do a "make install"!

  ___ Now we're waiting for the scp to creosote to finish.  Da de da,
      da de dum, hmm, hmm, dum de dum.

  ___ Now you need to go to 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 release.

      So, there's a directory called "2.2" which contains
      Python-2.2a2.exe and Python-2.2a2.tgz, along with a "prev"
      subdirectory containing Python-2.2a1.exe and Python-2.2a1.tgz.


    ___ On creosote, cd to ~ftp/pub/python/X.Y creating it if

    ___ 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.

    ___ Move the .tgz file and the .exe file to this directory.  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.

  ___ Update the X.Y/ file if necessary.  It is best to get
      BDFL input for this step.

  ___ Now preview the file once more.  IMPORTANT: follow
      every link on the page to make sure it goes where you expect it
      to go, and that what you expect to be there is there.

  ___ If everything looks good, move to and do a
      "make install" in this directory.  Go up to the parent directory
      (i.e. the root of the web page hierarchy) and do a "make
      install" there too.  You're release is now live!

  ___ 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 one of Guido's earlier announcements as a template, but
      please edit it for content!

      Once the announcement is ready, send it to the following

  ___ Send a SourceForge News Item about the release.  From the
      project's "menu bar", select the "News" link; once in News,
      select the "Submit" link.  Type a suitable subject (e.g. "Python
      2.2c1 released" :-) in the Subject box, add some text to the
      Details box (at the very least including the release URL at and the fact that you're happy with the release)
      and click the SUBMIT button.

      Feel free to remove any old news items.

  ___ Make the last two changes to the documentation area on  (Remember those from the documentation items above?
      It's time now.)

      In your pydotorg checkout, edit the file doc/ to update
      to the right version number and release date.  Commit the
      changes to CVS and push the file to the website:

        $ cd .../pydotorg/doc/
        $ make install

      This will cause the doc/index.html file to claim to point to the
      new docs, but they won't.  Run (don't walk!) to, and update a symlink in the doc/ tree:

        # on creosote:
        $ cd /ftp/
        $ rm current && ln -s $VERSION current

      Good.  Stop running.

    Now it's time to do some cleaning up.  These steps are very important!

  ___ If you made a non-maintenance branch, be sure to merge it into
      the trunk!  Now that we've released this branch, we don't need
      it any more.  We've already tagged it so we can always reproduce
      it.  Note that merging branches is a bit of a black art, but
      here's what's worked for us.

      NOTE: If this was an X.Y major release, we will be using this as
      the maintenance branch for a long time to come.

    ___ Check out a completely clean, virgin working directory of the
        trunk, by doing this in the directory that is the parent of
        your branch working directory python-XYaZ:
        % cvs -d <cvsroot> co -d python-clean python/dist/src

    ___ Run a diff against your branch by doing this in the common
        parent directory containing both python-clean and python-XYaZ:
        % diff -r python-clean python-22a2 | grep ^diff | grep -v CVS \
            > /tmp/

    ___ Edit to get rid of files that you know don't have
        important changes.  You're looking for files that have updates
        in the branch that haven't made it to the trunk.

        Generally you can ignore any changes to the Doc or Mac
        subdirectories, or any changes to Windows related files.  The
        sub-RMs for those parts will take care of any necessary merges
        from the branch to the trunk.

        If you've been diligent about merging changes from the trunk
        into the branch, there shouldn't be many of these files.

    ___ Edit /tmp/, changing all the -r's into -u's.  Run
        the /tmp/ command like so:
        % sh /tmp/ > /tmp/pydiff.txt

    ___ Attempt to patch your python-clean working directory.  Do this
        first, noting that --dry-run does not actually apply any
        patches, it just makes sure that the patch command runs
        successfully to completion:
        % patch -p1 --dry-run < /tmp/pydiff.txt

    ___ If this goes well, run it again, taking out the --dry-run
        option.  If this fails, or if it prompts you for a file to
        patch, try using -p0 instead of -p1.  Otherwise, your diff
        command was messed up, so try again.

    ___ cd to python-clean and do a "cvs commit".  Use as your log
        message something like "Merging the rXYaZ-maint tag back into
        the trunk".

    ___ Edit the file Include/patchlevel.h so that the PY_VERSION
        string says something like "X.YaZ+".  Note the trailing `+'
        indicating that the trunk is going to be moving forward with
        development.  E.g. the line should look like:

        #define PY_VERSION              "2.2a2+"

        Make sure that the other PY_ version macros contain the
        correct values.  Commit this change.

    ___ 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
        % ./configure
        % make test

        To ensure that the regression test suite passes.  If not, you
        screwed up somewhere!

    Step 5 ...

    Verify!  This can be interleaved with Step 4.  Pretend you're a
    user: download the files from, 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.

What Next?

    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!

    Actually, there is one more step.  You should turn over ownership
    of the branch to Jack Jansen.  All this means is that now he will
    be responsible for making commits to the branch.  He's going to
    use this to build the MacOS versions.  He may send you information
    about the Mac release that should be merged into the informational
    pages on  When he's done, he'll tag the branch
    something like "rX.YaZ-mac".  He'll also be responsible for
    merging any Mac-related changes back into the trunk.

Final Release Notes

    The Final release of any major release, e.g. Python 2.2 final, has
    special requirements, specifically because it will be one of the
    longest lived releases (i.e. betas don't last more than a couple
    of weeks, but final releases can last for years!).

    For this reason we want to have a higher coordination between the
    three major releases: Windows, Mac, and source.  The Windows and
    source releases benefit from the close proximity of the respective
    release-bots.  But the Mac-bot, Jack Jansen, is 6 hours away.  So
    we add this extra step to the release process for a final

    ___ Hold up the final release until Jack approves, or until we
        lose patience <wink>.

Windows Notes

    Windows has a GUI 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, Tim 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.

    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 (Tim uses "random" <wink>) and then that the "go to
    selected" button works.

    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 all of the above on at least one flavor of Win9x, and one
    of NT/2000.  On NT/2000, try both an Admin and a plain User (not
    Power User) account.

    WRT Step 5 above (verify the release media), since by the time
    release files are ready to download Tim has generally run many
    Windows tests on the installer he uploaded, he usually doesn't do
    anything for Step 5 except a full byte-comparison ("fc /b" if
    using a Windows shell) of the downloaded file against the file he


    This document has been placed in the public domain.