Python 3.0 upgrade incompatible with earlier versions

The Python Software Foundation is working concurrently on two upgrades to the core language and anticipates most people will stick with the Python 2 line for years

Python 3.0, a new version of the language released earlier this week, has incompatibilities with the 2.x line, according to the Python Software Foundation.

While saying the language is mostly the same, the foundation said details such as how built-in objects like dictionaries and strings work "have changed considerably and a lot of deprecated features have finally been removed." The standard library also has been reorganized to make it more accessible and discoverable.

Python vs. PHP: Choosing your next project's language

In a blog posting on Thursday, Guido van Rossum, lead developer of Python, called the 3.0 release "the first ever intentionally backwards incompatible Python release."

"There are more changes than in a typical release, and more that are important for all Python users. Nevertheless, after digesting the changes, you'll find that Python really hasn't changed all that much -- by and large, we're mostly fixing well-known annoyances and warts, and removing a lot of old cruft," van Rossum said.

Interviewed Friday morning, foundation representative David Goodger said "We fixed problems so we can go forward and add features more easily in the future without having to work around previous bad decisions."

A transitional release toward the 3.0 platform, Python 2.6, was released in October and updated with bug fixes in Python 2.6.1 this week. A Python 2.7 release also is planned, and the foundation anticipates most people will stick with the Python 2 line for years, Goodger said.

First released in 1991, Python is a general purpose language that has been popular in Web development. Among the new features in Python 3.0 are simplified rules for ordering comparisons, replacement of the print statement with a print function, and use of views and iterators instead of lists. Syntactic changes also have been made.

Python 3.0 uses concepts of text and binary data instead of Unicode strings and 8-bit strings. Text is Unicode but encoded Unicode is represented as binary data.

"As a consequence of this change in philosophy, pretty much all code that uses Unicode, encodings, or binary data most likely has to change," according to the foundation. But the change is for the better, the foundation said. With Python 3.0, the default way to handle text is to use Unicode throughout, Goodger said.

Featured with Python 2.6 is a tool called 2to3, to translate Python 2.6 code to Python 3.0. That tool will be improved along with the Python 2 line, Goodger said.

Python 3.0 is downloadable here.

Join the PC World newsletter!

Error: Please check your email address.

Tags python

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Paul Krill

InfoWorld

Most Popular Reviews

Follow Us

Best Deals on GoodGearGuide

Shopping.com

Latest News Articles

Resources

GGG Evaluation Team

Kathy Cassidy

STYLISTIC Q702

First impression on unpacking the Q702 test unit was the solid feel and clean, minimalist styling.

Anthony Grifoni

STYLISTIC Q572

For work use, Microsoft Word and Excel programs pre-installed on the device are adequate for preparing short documents.

Steph Mundell

LIFEBOOK UH574

The Fujitsu LifeBook UH574 allowed for great mobility without being obnoxiously heavy or clunky. Its twelve hours of battery life did not disappoint.

Andrew Mitsi

STYLISTIC Q702

The screen was particularly good. It is bright and visible from most angles, however heat is an issue, particularly around the Windows button on the front, and on the back where the battery housing is located.

Simon Harriott

STYLISTIC Q702

My first impression after unboxing the Q702 is that it is a nice looking unit. Styling is somewhat minimalist but very effective. The tablet part, once detached, has a nice weight, and no buttons or switches are located in awkward or intrusive positions.

Latest Jobs

Shopping.com

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?