Python language upgrade slithers toward final release

Python 2.7, the last version of the 2.x line, goes to release candidate stage with finished version scheduled for July 3

Python 2.7, the last in the legacy Python 2.x dynamic language line, moved closer to general availability earlier this month when developers of the language put out a release candidate.

The finished version of Python 2.7 is scheduled to be available July 3, after a second release candidate is offered on July 19, said Steve Holden, chairman of the Python Software Foundation.

[ Earlier this week, InfoWorld's Paul Krill reported that Ruby on Rails 3.0 is due out as a release candidate. ]

"Yes, 2.7 represents the last of the 2.x series at least as far as the development team is concerned. We anticipate a long period of end-of-life support -- most likely at least five years but certainly beyond the normal two years," Holden said Thursday evening.

Python has been popular in Web development. A 3.x line already exists. Python developers made the decision to upgrade to the 3.x line, which is incompatible with the 2.x line, because developers sought to make some changes more dramatic than a typical upgrade while still maintaining the essence of Python.

"A number of 3.1 features have been back-ported (to Python 2.7) including set literals, dictionary and set comprehensions -- an easy way of programmatically generating data -- and the new 'io' module. All these features will aid people in migrating to the 3.x series when the time comes," Holden said.

Meanwhile, development also continues on the 3.x line, Holden said.

"You may be aware that the developers have adopted what they are referring to as a 'language moratorium' -- no new language features are going to be added in the next 15 months. It was felt this period of stability will be helpful to Python users, though there is no prohibition about adding new functionality to the standard library," said Holden.

"We currently anticipate the first beta [of Python 3.2] in September of this year, with the final release arriving in December," Holden said.

The major change in version 3.2, Holden said, "is a re-write of the 'Global Interpreter Lock' that ensures thread consistency. It was discovered that under certain circumstances programs would run inefficiently on multi-CPU machines, and the rewrite will fix that."

"Apart from that the only definite significant changes relate to the handling of conversions between Unicode strings and other representations," Holden said.

"By the time the release comes around there will be other changes - feature freeze occurs only when the first beta is released," Holden added.

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