Alternative Implementations

This site hosts the "traditional" implementation of Python (nicknamed CPython). A number of alternative implementations are available as well, namely

• IronPython (Python running on .NET)
• Jython (Python running on the Java Virtual Machine)
• PyPy (A fast python implementation with a JIT compiler)
• Stackless Python (Branch of CPython supporting microthreads)

Download Python

The current production versions are Python 2.7.3 and Python 3.2.3.

Start with one of these versions for learning Python or if you want the most stability; they're both considered stable production releases.

If you don't know which version to use, start with Python 2.7; more existing third party software is compatible with Python 2 than Python 3 right now.

For the MD5 checksums and OpenPGP signatures, look at the detailed Python 2.7.3 page:

• Python 2.7.3 Windows Installer (Windows binary -- does not include source)
• Python 2.7.3 Windows X86-64 Installer (Windows AMD64 / Intel 64 / X86-64 binary [1] -- does not include source)
• Python 2.7.3 Mac OS X 64-bit/32-bit x86-64/i386 Installer (for Mac OS X 10.6 and 10.7 [2])
• Python 2.7.3 Mac OS X 32-bit i386/PPC Installer (for Mac OS X 10.3 through 10.6 [2])
• Python 2.7.3 compressed source tarball (for Linux, Unix or Mac OS X)
• Python 2.7.3 bzipped source tarball (for Linux, Unix or Mac OS X, more compressed)

Also look at the detailed Python 3.2.3 page:

• Python 3.2.3 Windows x86 MSI Installer (Windows binary -- does not include source)
• Python 3.2.3 Windows X86-64 MSI Installer (Windows AMD64 / Intel 64 / X86-64 binary [1] -- does not include source)
• Python 3.2.3 Mac OS X 64-bit/32-bit x86-64/i386 Installer (for Mac OS X 10.6 and 10.7 [2])
• Python 3.2.3 Mac OS X 32-bit i386/PPC Installer (for Mac OS X 10.3 through 10.6 [2])
• Python 3.2.3 compressed source tarball (for Linux, Unix or Mac OS X)
• Python 3.2.3 bzipped source tarball (for Linux, Unix or Mac OS X, more compressed)

A comprehensive list of the latest release of all major versions is available if you need source code for an older version of Python.

Other parties have re-packaged Python. These re-packagings often include more libraries or are specialized for a particular application:

• ActiveState ActivePython (commercial and community versions, including scientific computing modules)
• pythonxy (Scientific-oriented Python Distribution based on Qt and Spyder)
• Conceptive Python SDK (targets business, desktop and database applications)
• Enthought Python Distribution (a commercial distribution for scientific computing)
• Portable Python (Python and add-on packages configured to run off a portable device)
• PyIMSL Studio (a commercial distribution for numerical analysis – free for non-commercial use)

Information about specific ports, and developer info:

• Windows (and DOS)
• Macintosh
• Other platforms
• Source
• Python Developer's Guide
• Python Issue Tracker

OpenPGP Public Keys

Source and binary executables are signed by the release manager using their OpenPGP key. The release managers since Python 2.3 have been:

• Anthony Baxter (key id: 6A45C816)
• Georg Brandl (key id: 36580288)
• Martin v. Löwis (key id: 7D9DC8D2)
• Benjamin Peterson (key id: A4135B38)
• Barry Warsaw (key id: EA5BBD71 and ED9D77D5)
• Ronald Oussoren (key id: E6DF025C)
• Ned Deily (key id: 6F5E1540)

Note: Barry's key id EA5BBD71 is used to sign all Python 2.6 and 3.0 releases. His key id ED9D77D5 is a v3 key and was used to sign older releases.

You can import the release manager public keys by either downloading the public key file from here and then running

% gpg --import pubkeys.txt

or by grabbing the individual keys directly from the keyserver network by running this command:

% gpg --recv-keys EA5BBD71 6A45C816 ED9D77D5 \
    7D9DC8D2 A4135B38 36580288

On the version-specific download pages, you should see a link to both the downloadable file and a detached signature file. To verify the authenticity of the download, grab both files and then run this command:

% gpg --verify Python-3.2.3.tgz.asc

Note that you must use the name of the signature file, and you should use the one that's appropriate to the download you're verifying.

• (These instructions are geared to GnuPG and Unix command-line users. Contributions of instructions for other platforms and OpenPGP applications are welcome.)

Other Useful Items

• Looking for 3rd party Python modules? The Package Index has many of them.
• You can view the standard documentation online, or you can download it in HTML, PostScript, PDF and other formats. See the main Documentation page.
• Information on tools for unpacking archive files provided on python.org is available.
• Tip: even if you download a ready-made binary for your platform, it makes sense to also download the source. This lets you browse the standard library (the subdirectory Lib) and the standard collections of demos (Demo) and tools (Tools) that come with it. There's a lot you can learn from the source!
• There is also a collection of Emacs packages that the Emacsing Pythoneer might find useful. This includes major modes for editing Python, C, C++, Java, etc., Python debugger interfaces and more. Most packages are compatible with Emacs and XEmacs.

Want to contribute? See the Python Developer's Guide to learn about how Python development is managed.

Python is OSI Certified Open Source:

[1]	(1, 2) The binaries for AMD64 will also work on processors that implement the Intel 64 architecture (formerly EM64T), i.e. the architecture that Microsoft calls x64, and AMD called x86-64 before calling it AMD64. They will not work on Intel Itanium Processors (formerly IA-64).

[2]	(1, 2, 3, 4) There is important information about IDLE, Tkinter, and Tcl/Tk on Mac OS X here.