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  • Python 2.4.1 - Release Notes

    ...c=1,2,3". Improves their speed by 25% to 30%. Limit the nested depth of a tuple for the second argument to isinstance() and issubclass() to the recursion limit of the interpreter. Fixes bug #858016 . Optimized dict iterators, creating separate types for each and having them reveal their length. Also optimized the methods: keys(), values(), and items(). Implemented a newcode opcode, LIST_APPEND, that simplifies the generated bytecode for list comprehensions and further improves their per...

  • Python Software Foundation: Missing 1023 form

    Python Software Foundation: Missing 1023 form The text of the letter from the IRS is below. You can also view a scanned image of the letter (118KB PNG; 1.1MB TIFF). Internal Revenue Service Date: May 6, 2004 Python Software Foundation c/o Zone Corporation 513 Prince Edward ST Fredericksberg, VA 22401-5742 Department of the Treasury P. 0. Box 2508 Cincinnati. OH 45201 Person to Contact: Ms. Dalton 31-07967 Customer Service Representative Toll Free Tel...

  • Release – Python 3.13.4

    Version: None

    Released: June 3, 2025

    This is the fourth maintenance release of Python 3.13 Python 3.13 is the newest major release of the Python programming language, and it contains many new features and optimizations compared to Python 3.12. 3.13.4 is the latest maintenance release, containing a few important security fixes as well as around …

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  • Release – Python 3.13.11

    Version: None

    Released: Dec. 5, 2025

    This is the eleventh maintenance release of Python 3.13 Note: This is Python 3.13.11, a maintenance release for Python 3.13. Python 3.14 is now the latest feature release series of Python 3. Get the latest release of 3.14.x here. Python 3.13.11 is the eleventh maintenance release of …

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  • Python Success Stories

    Python Success Stories Introduction The GravityZoo Company, founded in late 2005 is a pioneering innovator of Software as a Service (SaaS) enabling technology, Ubiquitous Computing and Ambient Intelligence Systems. The core technology of the Company is its framework. This GravityZoo Framework is designed to develop and host any kind of application while simultaneously making these applications available at anytime, anyplace. The latter on any type of client device, be it a PC, a mobile client...

  • Debugging Reference Count Problems

    Debugging Reference Count Problems Warning This page stays here for historical reasons and it may contain outdated or incorrect information. Debugging Reference Count Problems From: Guido van Rossum <guido@CNRI.Reston.VA.US> To: python-list@cwi.nl Date: Wed, 27 May 1998 11:09:40 -0400 Mike Fletcher wrote a number of posts about debugging C code that bombs, probably because of reference count problems. His approach to debugging this problem seems typical, but I thin...

  • Ancient Releases

    Ancient Releases Andrew Dalke was clever and persistent enough to scrape Python 0.9.1 out of the Usenet alt.sources archives and assemble a compressed tarball. It's here mostly as a historical relic. If you want a compiled binary (on Linux) you can install it with conda (ideally in its own conda environment): conda install -c davidmertz python=0.9 Skip Montanaro has created a GitHub repository of Python 0.9.1 source.

  • Python Success Stories

    Python Success Stories Introducing IronPython Pairing the Python language's expressivity with the seamless availability of the extensive .NET class libraries makes IronPython a powerful combination for Resolver Systems. About Resolver Systems Resolver Systems is a two year-old start-up based on the outskirts of London's financial district. Our first product, Resolver One, is a desktop and web-accessible spreadsheet aimed primarily at the financial services market. It is written entirely in ...

  • Matching Donations

    Matching Donations Did you know many companies offer a matching gift program to encourage philanthropy among their employees? And that some companies will even match gifts made by family members and retirees? By completing a matching gift form (online or paper), you may be able to double, or even triple, the impact of your gift. Contributions of any amount help us award grants and provide resources for furthering the development of a diverse and international community of Python programmers...

  • Release – Python 3.9.3

    Version: None

    Released: April 2, 2021

    This is the third maintenance release of Python 3.9 NOTE: The release you're looking at has been recalled due to unintentional breakage of ABI compatibility with C extensions built in Python 3.9.0 - 3.9.2. Details in bpo-43710. Please use Python 3.9.4 or newer instead. Python …

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  • Release – Python 3.13.0rc3

    Version: None

    Released: Oct. 1, 2024

    This is the third release candidate of Python 3.13.0 This release, 3.13.0rc3, is the final release preview (no really) of 3.13. This release is expected to become the final 3.13.0 release, barring any critical bugs being discovered. The official release of 3.13.0 is now scheduled for Monday, 2024-10-07. …

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  • Release – Python 3.13.1

    Version: None

    Released: Dec. 3, 2024

    This is the first maintenance release of Python 3.13 Python 3.13 is the newest major release of the Python programming language, and it contains many new features and optimizations compared to Python 3.12. 3.13.1 is the latest maintenance release, containing almost 400 bugfixes, build improvements and documentation changes since …

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  • Release – Python 3.14.3

    Version: None

    Released: Feb. 3, 2026

    This is third maintenance release of Python 3.14 Python 3.14.3 is the third maintenance release of 3.14, containing around 299 bugfixes, build improvements and documentation changes since 3.14.2. Major new features of the 3.14 series, compared to 3.13 Some of the major new features and changes …

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  • Python Success Stories

    Python Success Stories Introduction Frequentis is one of the world's leading providers for safety-critical solutions in the field of Air Traffic Management and Public Safety & Transport. With over 500 employees world-wide, it provides innovative, user-centered solutions to its customers. Frequentis has been using Python in its TAPtools® product family, which focuses on the Tower and Airport Tools segment of Air Traffic Control. These tools are used by air traffic controllers to track weat...

  • Release – Python 3.14.0b4

    Version: None

    Released: July 8, 2025

    It's the final 3.14 beta! https://www.python.org/downloads/release/python-3140b4/ This is a beta preview of Python 3.14 Python 3.14 is still in development. This release, 3.14.0b4, is the last of four planned beta releases. Beta release previews are intended to give the wider community the opportunity to test new …

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  • Python Success Stories

    Python Success Stories Summary XIST is a XML transformation engine written completely in Python at LivingLogic AG, a software development company specializing in web technology. XIST was designed to facilitate the task of creating and maintaining large web sites. Background Soon after we began creating web pages in 1994, it became clear that typing HTML files by hand is tedious and cumbersome, and we began to search for tools to simplify the repetitive task of HTML generation. Early on, we ...

  • Python Software Foundation Public Records

    Python Software Foundation Public Records Incorporation Here is a transcript of the Articles of Incorporation. Bylaws Here are the PSF Bylaws. Board of Directors PSF Board Members & Officers Resolutions Meeting Minutes Python Software Foundation Policies: Conflict of Interest Policy Whistleblower Policy Python.org Email Policy PSF Staff Current staff IRS recognition of tax exempt status The PSF is a United States 501(c)(3) corporation domiciled in Delaware. Final determ...

  • Release – Python 3.7.0a1

    Version: None

    Released: Sept. 19, 2017

    This is an early developer preview of Python 3.7 Major new features of the 3.7 series, compared to 3.6 Python 3.7 is still in development. This releasee, 3.7.0a1 is the first of four planned alpha releases. Alpha releases are intended to make it easier to test the …

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  • Release – Python 3.14.0a4

    Version: None

    Released: Jan. 14, 2025

    Hello, three dot fourteen dot zero alpha four! This is an early developer preview of Python 3.14 Major new features of the 3.14 series, compared to 3.13 Python 3.14 is still in development. This release, 3.14.0a4, is the fourth of seven planned alpha releases. Alpha releases …

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  • Release – Python 3.14.0b3

    Version: None

    Released: June 17, 2025

    It's 3.14 beta 3! https://www.python.org/downloads/release/python-3140b3/ This is a beta preview of Python 3.14 Python 3.14 is still in development. This release, 3.14.0b3, is the third of four planned beta releases. Beta release previews are intended to give the wider community the opportunity to test new features …

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