1 This is Python version 3.0 alpha 4
2 ==================================
4 For notes specific to this release, see RELNOTES in this directory.
5 Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
6 Python Software Foundation.
9 Python 3000 (a.k.a. "Py3k", and released as Python 3.0) is a new
10 version of the language, which is incompatible with the 2.x line of
11 releases. The language is mostly the same, but many details,
12 especially how built-in objects like dictionaries and strings work,
13 have changed considerably, and a lot of deprecated features have
16 This is an ongoing project; the cleanup isn't expected to be complete
17 until some time in 2008. In particular there are plans to reorganize
18 the standard library namespace.
24 The release plan is to have a series of alpha releases in 2007 and 2008,
25 beta releases in 2008, and a final release in August 2008. The alpha
26 releases are primarily aimed at developers who want a sneak peek at the
27 new langauge, especially those folks who plan to port their code to
28 Python 3000. The hope is that by the time of the final release, many
29 3rd party packages will already be available in a 3.0-compatible form.
31 See PEP 361 for release details: http://www.python.org/dev/peps/pep-0361/
37 Documentation for Python 3000 is online, updated twice a day:
39 http://docs.python.org/dev/3.0/
41 All documentation is also available online at the Python web site
42 (http://docs.python.org/, see below). It is available online for
43 occasional reference, or can be downloaded in many formats for faster
44 access. The documentation is downloadable in HTML, PostScript, PDF,
45 LaTeX (through 2.5), and reStructuredText (2.6+) formats; the LaTeX and
46 reStructuredText versions are primarily for documentation authors,
47 translators, and people with special formatting requirements.
49 This is a work in progress; please help improve it!
51 The design documents for Python 3000 are also online. While the
52 reference documentation is being updated, the PEPs are often the best
53 source of information about new features. Start by reading PEP 3000:
55 http://python.org/dev/peps/pep-3000/
61 For an overview of what's new in Python 3000, see Guido van Rossum's
64 http://www.artima.com/weblogs/index.jsp?blogger=guido
66 We try to eventually have a comprehensive overview of the changes in
67 the "What's New in Python 3.0" document, found at
69 http://docs.python.org/dev/3.0/whatsnew/3.0
73 If you want to install multiple versions of Python see the section below
74 entitled "Installing multiple versions".
77 What's New Since 3.0a1
78 ----------------------
80 Undoubtedly the biggest change is in the bytes type: 'bytes' is now
81 immutable, and there is a new mutable bytes type 'bytearray'. These
82 two types are interoperable in every way. For more info on this
85 For a more detailed change log, read Misc/NEWS (though this file, too,
86 is incomplete, and also doesn't list anything merged in from the 2.6
87 release under development).
89 Proposals for enhancement
90 -------------------------
92 If you have a proposal to change Python, you may want to send an email to the
93 comp.lang.python or python-ideas mailing lists for inital feedback. A Python
94 Enhancement Proposal (PEP) may be submitted if your idea gains ground. All
95 current PEPs, as well as guidelines for submitting a new PEP, are listed at
96 http://www.python.org/dev/peps/.
98 Converting From Python 2.x to 3.0
99 ---------------------------------
101 Python 2.6 (not yet released) will contain features to help locating
102 code that needs to be changed, such as optional warnings when
103 deprecated features are used, and backported versions of certain key
104 Python 3000 features.
107 Installing multiple versions
108 ----------------------------
110 On Unix and Mac systems if you intend to install multiple versions of Python
111 using the same installation prefix (--prefix argument to the configure
112 script) you must take care that your primary python executable is not
113 overwritten by the installation of a different versio. All files and
114 directories installed using "make altinstall" contain the major and minor
115 version and can thus live side-by-side. "make install" also creates
116 ${prefix}/bin/python which refers to ${prefix}/bin/pythonX.Y. If you intend
117 to install multiple versions using the same prefix you must decide which
118 version (if any) is your "primary" version. Install that version using
119 "make install". Install all other versions using "make altinstall".
121 For example, if you want to install Python 2.5, 2.6 and 3.0 with 2.6 being
122 the primary version, you would execute "make install" in your 2.6 build
123 directory and "make altinstall" in the others.
126 Configuration options and variables
127 -----------------------------------
129 A source-to-source translation tool, "2to3", can take care of the
130 mundane task of converting large amounts of source code. It is not a
131 complete solution but is complemented by the deprecation warnings in
132 2.6. This tool is currently available via the Subversion sandbox:
134 http://svn.python.org/view/sandbox/trunk/2to3/
137 Issue Tracker and Mailing List
138 ------------------------------
140 We're soliciting bug reports about all aspects of the language. Fixes
141 are also welcome, preferable in unified diff format. Please use the
144 http://bugs.python.org/
146 If you're not sure whether you're dealing with a bug or a feature, use
149 python-3000@python.org
151 To subscribe to the list, use the mailman form:
153 http://mail.python.org/mailman/listinfo/python-3000/
159 On Unix, Linux, BSD, OSX, and Cygwin:
164 sudo make install # or "make altinstall"
166 You can pass many options to the configure script; run "./configure
167 --help" to find out more. On OSX and Cygwin, the executable is called
168 python.exe; elsewhere it's just python.
170 On Mac OS X, if you have configured Python with --enable-framework,
171 you should use "make frameworkinstall" to do the installation. Note
172 that this installs the Python executable in a place that is not
173 normally on your PATH, you may want to set up a symlink in
176 On Windows, see PCbuild/readme.txt.
178 If you wish, you can create a subdirectory and invoke configure from
183 ../configure --with-pydebug
187 (This will fail if you *also* built at the top-level directory. You
188 should do a "make clean" at the toplevel first.)
191 Copyright and License Information
192 ---------------------------------
194 Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
195 Python Software Foundation.
198 Copyright (c) 2000 BeOpen.com.
201 Copyright (c) 1995-2001 Corporation for National Research Initiatives.
204 Copyright (c) 1991-1995 Stichting Mathematisch Centrum.
207 See the file "LICENSE" for information on the history of this
208 software, terms & conditions for usage, and a DISCLAIMER OF ALL
211 This Python distribution contains *no* GNU General Public License
212 (GPL) code, so it may be used in proprietary projects. There are
213 interfaces to some GNU code but these are entirely optional.
215 All trademarks referenced herein are property of their respective