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Python 2.5.1

Release Date: April 19, 2007

Python 2.5.1 was released on April 18th, 2007.

This is the first bugfix release of Python 2.5. Python 2.5 is now in bugfix-only mode; no new features are being added. According to the release notes, over 150 bugs and patches have been squished since Python 2.5, including a fair number in the new AST compiler (an internal implementation detail of the Python interpreter).

See the detailed release notes for more details.

Since the release candidate, we have backed out a couple of small changes that caused 2.5.1 to behave differently to 2.5. Again, see the release notes for more.

For more information on the new features of Python 2.5.1 see the 2.5 highlights or consult Andrew Kuchling's What's New In Python for a more detailed view.

Please see the separate bugs page for known issues and the bug reporting procedure.

See also the license.

Download the release


For x86 processors: python-2.5.1.msi

For Win64-Itanium users: python-2.5.1.ia64.msi

For Win64-AMD64 users: python-2.5.1.amd64.msi

This installer allows for automated installation and many other new features.

To use these installers, the Windows system must support Microsoft Installer 2.0. Just save the installer file to your local machine and then run it to find out if your machine supports MSI.

Windows XP and later already have MSI; many older machines will already have MSI installed.

If your machine lacks Microsoft Installer, you'll have to download it freely from Microsoft for Windows 95, 98 and Me and for Windows NT 4.0 and 2000.

Windows users may also be interested in Mark Hammond's pywin32 package, available from Sourceforge. pywin32 adds a number of Windows-specific extensions to Python, including COM support and the Pythonwin IDE.


For MacOS X 10.3 and later: python-2.5.1-macosx.dmg. This is a Universal installer.

The Universal OS X image contains an installer for python 2.5.1 that works on Mac OS X 10.3.9 and later, on both PPC and Intel Macs. The compiled libraries include both bsddb and readline.

Other platforms

gzip-compressed source code: Python-2.5.1.tgz

bzip2-compressed source code: Python-2.5.1.tar.bz2, the source archive.

The bzip2-compressed version is considerably smaller, so get that one if your system has the appropriate tools to deal with it.

Unpack the archive with tar -zxvf Python-2.5.1.tgz (or bzcat Python-2.5.1.tar.bz2 | tar -xf -). Change to the Python-2.5.1 directory and run the "./configure", "make", "make install" commands to compile and install Python. The source archive is also suitable for Windows users who feel the need to build their own version.

What's New?

  • See the highlights of the Python 2.5 release.
  • Andrew Kuchling's What's New in Python 2.5 describes the most visible changes since Python 2.4 in more detail.
  • A detailed list of the changes in 2.5.1 can be found in the release notes, or the Misc/NEWS file in the source distribution.
  • For the full list of changes, you can poke around in Subversion.


The documentation has also been updated:

  • Download using HTTP.
  • Documentation is available in Windows Help (.chm) format - Python25.chm.

Files, MD5 checksums, signatures and sizes

cca695828df8adc3e69b637af07522e1 Python-2.5.1.tgz (11060830 bytes, signature)

70084ffa561660f07de466c2c8c4842d Python-2.5.1.tar.bz2 (9383651 bytes, signature)

a1d1a9c07bc4c78bd8fa05dd3efec87f python-2.5.1.msi (10970624 bytes, signature)

5cf96e05ad6721f90cdd9da146981640 python-2.5.1.amd64.msi (10983936 bytes, signature)

75347f7637a998765701088261bdd5cd python-2.5.1.ia64.msi (13201920 bytes, signature)

59796329bc160a3a1e2abc01bf30bb50 python-2.5.1-macosx.dmg (18719946 bytes, signature)

ee652cd776cf930a0a40ff64c436f0b1 Python25.chm (4176034 bytes, signature)

The signatures above were generated with GnuPG using release manager Anthony Baxter's public key which has a key id of 6A45C816.

Full Changelog


Version Operating System Description MD5 Sum File Size GPG
Gzipped source tarball Source release 968039b3b2a077061d11671e1c6b40a2 44.6 MB SIG
bzip2 compressed source tarball Source release 70084ffa561660f07de466c2c8c4842d 8.9 MB SIG
Mac OS X installer macOS 59796329bc160a3a1e2abc01bf30bb50 17.9 MB SIG
Windows help file Windows ee652cd776cf930a0a40ff64c436f0b1 4.0 MB SIG
Windows x86 MSI installer Windows a1d1a9c07bc4c78bd8fa05dd3efec87f 10.5 MB SIG
Windows x86-64 MSI installer Windows for AMD64/EM64T/x64 5cf96e05ad6721f90cdd9da146981640 10.5 MB SIG