Python 3.3.0 Released

An anonymous reader writes "After just over a month of release candidates, the final version of Python 3.3 launched today. This version includes new syntax, including the yield from expression for generator delegation; new library modules, including fault handler (for debugging crashes), ipaddress, and lzma (for data compression using the XZ/LZMA algorithm); a reworked OS and I/O exception hierarchy; the venv module for programmatic access to Python virtual environments; and a host of API changes. The full list of features and the change log are both available."

Re:Python 3 and its use

[melonman]

"It's probably now at the point where new projects are better off starting with Python 3, to ease the pain of upgrading later, unless there's a library they really need. Starting with a mature (but depreciated) platform is not a great idea."

Unless you want to use Python on Google App Engine, where Python 2.7 is what you get. And given that Guido himself works for Google on this project, that's not exactly encouraging.

Or unless you want a Python app to work out of the box on, well, just about anything, but OSX is the example that bit me.

I remember discussing Python 3 on /. when it came out. The decision not to even try to ensure backwards compatibility struck me as disastrous. The response was "No, because Python will never have a cruft problem because we are not Perl coders", or something like that. Many years on, I still think it was disastrous. Python now has a bigger legacy code problem than Perl - seen much Perl 4 recently? - precisely because the upgrade path is such a pain.

Killing Python 2 is going to be like killing IE6 and Windows XP - a noble goal that turns out to take decades. And it's a totally self-inflicted wound by the Python community.

Python 2.7.3 is the new IE6

[csumpi]

While I like some of the changes in python3, breaking compatibility with python2 was a huge fail.

From python3 release notes (dated December 3rd, 2008):

'''Python 3.0 (a.k.a. "Python 3000" or "Py3k") is a new version of the language that is incompatible with the 2.x line of releases. The language is mostly the same, but many details, especially how built-in objects like dictionaries and strings work, have changed considerably, and a lot of deprecated features have finally been removed. Also, the standard library has been reorganized in a few prominent places.'''

This was four (4) years ago. Major linux distributions are still on python2. Many python2 packages are still hard to come by for python3. Popular libraries (for example opencv) still link to python2. Even google searches for python docs go to python2.

Python 2.7.3 is the new IE6.

Because .py3 wasn't used

[tepples]

One reason why Python 3 hasn't taken off is that it didn't adopt .py3 as a file name suffix for Python 3 programs. This makes side-by-side installation of Python 2 and Python 3 much more difficult. Does Python 3.3 yet have a feature where I can have both Python 2 and Python 3 installed on a PC running Windows, and double-clicking a .py file in Windows Explorer runs the correct interpreter version? Until that's fixed, with a .py handler that starts Python 2 or Python 3 depending on future statements or the shebang line, Python 3 won't take off.