Source Access Via CVS

Python is an open source project, and in that spirit, we are dedicated to providing the source code in its purest form to any interested developer. Internally, we maintain Python under the CVS revision control system. Until now, we have made a public read-only mirror of the CVS tree available only to the Python Software Activity. After polling the PSA membership, we have decided to open the tree up to everyone. We still encourage you to join the PSA and help support Python's future development.

This page briefly describes the public CVS tree, what is available, and how to do checkouts of the code. You can also get notified of new checkins via email. If you plan on generating patches to Python, we highly encourage you to grab the CVS snapshot, and generate patches against it. It is possible that your problem has already been fixed, and if not, it makes our job of integrating your changes much easier if it applicable to the current source code.

What is available?

Essentially the entire Python distribution, including documentation!

In fact, the entire current snapshot is always available, and our changes to the internal source tree are immediately reflected in the read-only CVS mirror. This means that if you want to stay on the bleeding edge of Python development, you can easily do so by checking out the source tree, and updating as changes are checked in by Guido and others on the development team. If you are more inclined to wait until more stable versions are officially released, then wait for Guido's announcements on the appropriate mailing lists, newsgroups, and Web sites.

You may also want to check out Mark Hammond's Pythonwin CVS tree, and Jack Jansen's MacPython CVS distribution.

Greg Stein has written a wonderful tool called ViewCVS. We're using this tool to make all of the public projects hosted at Python.Org available via our online repository.

Also, David Ascher is making nightly tarballs of the CVS tree available on Starship. For those of you having trouble accessing CVS through your firewall, this might be a viable alternative. David is also making tarballs available for Zope and PyOpenGL.

What is CVS?

`CVS' stands for the Concurrent Version System, a free version control system that we use to manage changes in the development tree of the Python source code. CVS clients are freely available for Unix, Windows, and MacOS so any PSA member who wants to have access to the Python source tree should be able to do so. For more information on obtaining a CVS client for your system, see the Cyclic Web pages. Note that you will want to use CVS 1.9 or better.

Checking out the Python source

The first thing you need to do is log into the remote CVS server. You do this by executing the following command (assuming Unix):

% cvs -d :pserver:pythoncvs@cvs.python.org:/projects/cvsroot login

This will prompt you for a password; enter snakeoil.

Once you've logged in, you can do your initial checkout:

% cvs -z6 -d :pserver:pythoncvs@cvs.python.org:/projects/cvsroot co python

Once you've done the intial checkout, you can stay current by cd'ing into the python subdirectory and typing:

% cvs -z6 -q up -P -d

where -q says to be quiet, -z6 says to use level 6 compression (a good tradeoff between improved network performance and CPU usage), -P says to prune empty directories (good for ignoring obsolete directories), and -d says to check out newly added directories.

Note that after the initial checkout, you do not need to specify the repository to use. CVS remembers this automatically.

Getting notification of changes

When Guido or any other member of the development team, make changes to the internal source tree, two things happen immediately. First, the change is copied out to the public read-only mirror on cvs.python.org. This means that you always have access to exactly the tree we have in front of us. Second, the log message for the change is sent to a mailing list that you can subscribe to. Note that it is a read-only list; you cannot post messages, so use normal channels for communicating back to Guido and the development team.

Also note that this mailing list is not archived, since all the information is available already through the CVS log commands.

Other distribution mechanisms

Currently anonymous CVS is the only access method available, however many people (especially those outside the USA) have indicated that remote CVS is pretty inefficient. As time allows, we'll investigate making other options for accessing the source tree available. Watch here for further instructions.