Python 3.0 Released

http://www.python.org/download/releases/3.0

by zain • 18 years ago

147 60 18 years ago

makecheck• 18 years ago

http://news.ycombinator.com/item?id=384897

petercooper4• 18 years ago

This official announcement and summary is a lot better than that linked from that old post. Of course, the HN comments there are worth reading nonetheless.

petercooper4• 18 years ago

So much cleaner and more consistent. Classic classes are gone for good!

Unlike with other languages (which I won't name for fear of offense!) I think Pythonistas will actually migrate to this much improved Python (well, forgetting the 10% performance hit) especially as such focus has been put into making tools to make it easier, unlike with PHP 4->5 (oops..!)

thorax• 18 years ago

I'll miss __coerce__. :(

joestrickler2• 18 years ago

Sorry, no. I do most of my work in Python and would love to see quick Py3k adoption. But 2.3 was released 29-Jul-2003 and is still the baseline for portable code. Pythonistas are just as much a victim to the forces against migration as PHP and "other language" coders.

Just for kicks, try getting a stable webapp stack running on 2.6. I'm still not near ready to put that into production (and I run tiny, tiny websites).

lacker• 18 years ago

Google App Engine uses 2.5.2 and that seems stable.

http://code.google.com/appengine/docs/whatisgoogleappengine....

kaens4• 18 years ago

I run a stable CherryPy app on 2.6 . It was a bit painful for about a week after 2.6 came out, but became stable pretty fast.

There are a whole lot of possibilities for a "webapp stack" in python. What are you running your sites on top of?

etal3• 18 years ago

The latest draft of Linux Standard Base appears to specify Python 2.4. I wish we could rely on everyone having ctypes and ElementTree in the standard library, but no luck.

(I think web.py 0.3 and possibly the trunk of Django can handle Py2.6, but obviously they're not going to drop support for older versions any time soon.)

mahipal• 18 years ago

Any elaboration on where the 10% performance hit comes from?

I read over the "What's New" and Guido's announcement, but I didn't find any mention of it.

kaens4• 18 years ago

Most likely the biggest cause is the removal of special-casing for small integers.

http://docs.python.org/dev/3.0/whatsnew/3.0.html#performance

I'm anticipating a more thorough discussion of this on python-list or python-dev in the near future.

petercooper4• 18 years ago

Under "Performance" at http://docs.python.org/dev/3.0/whatsnew/3.0.html :

The net result of the 3.0 generalizations is that Python 3.0 runs the pystone benchmark around 10% slower than Python 2.5. Most likely the biggest cause is the removal of special-casing for small integers. There’s room for improvement, but it will happen after 3.0 is released!

breck• 18 years ago

True, migrating to PHP4 to 5 wasn't pretty, but 5 was an order of magnitude improvement over 4 and so worth the cost. Not sure if the same can be said for this new Py release. I'm still doing everything in 2.6(which was a recent move from 2.5). Too many libraries that aren't out for 3 yet.

etal3• 18 years ago

Also, a lot of the scripts that power Gnome and Debian are written in Python. Ubuntu also seems to do most new work in Python. So I expect Python 2.X to be the default in distros for quite some time, probably until a 3.1 release or later.

illumen• 18 years ago

Remember python 3.0 is supposed to be an intermediate for migration release... not for production use. That's what 3.1 is for.

It's going to take ages for modules to get converted over... but most projects have been preparing for it for a while. However hopefully the migration scripts will get better over the 3.0 - 3.1 timeline.

For now I'm sticking with python 2.5 - since it's the best one considering it's far better module, and platform support.

cl-user• 18 years ago

> Remember python 3.0 is supposed to be an intermediate for migration release... not for production use. That's what 3.1 is for.

From the release page (http://www.python.org/download/releases/3.0/): This is a production release; we currently support these formats: ...

That said, I also plan to keep my core projects on 2.x for a few more months till django, ipython, debian repos etc. move to 3.x. But I do plan to play with 3.x some.

charcoal• 18 years ago

> It's going to take ages for modules to get converted over...

You underestimate the power of the ... wait a sec. :)

Anyway, there's broad support and excitement in the community about this release. I think you'll see modules being updated more quickly than you suspect.

juanpablo• 18 years ago

I think that's python2.6

wesm• 18 years ago

NumPy and other libraries aren't working 100% (have some breaking tests) on Python 2.6 yet due to some C API changes

msie• 18 years ago

Initially I was excited about 3.0 but as you pointed out it will take some time for modules to get converted over. I think this is very important. For me, one of the big selling points of Python is the large number of libraries written for it. With my luck I will need to use an obscure library that won't be updated any time soon by the author. So I'll have to stick with 2.5 or 2.6 because I need to get my job done rather than migrate a library.

It's sort of a chicken-and-egg problem because without widespread use of 3.0 no one will feel pressure to upgrade their library. I'm hoping, out of the goodness of their own hearts, that everyone will upgrade their libraries (for no immediate benefit but the gratitude of 3.0 users!). Maybe a website badge should be created for this accomplishment!

marcher2• 18 years ago

Python 3.0 includes a script that tries to automatically convert 2.6 code to 3.0 code, named 2to3. It's also incorporated into the package setup library, so in theory simply installing a Python 2.6 package with 3.0 will automatically convert the source code.

Of course, that means making your code work with 2to3 to begin with, but that's a much lower barrier to adoption than outright porting and dual maintenance.

FiReaNG3L• 18 years ago

Guess it's a good time to learn Python!

EliAndrewC• 18 years ago

I agree that it's a good time to learn Python... because it's always a good time to learn Python.

However, be aware that no one in the Python community expects 3.x to be used widely for a few years. Even for new projects, if you want to depend on an existing 3rd party library that hasn't yet been ported, you'll probably have to stick with 2.6.

To accommodate this, they allow you to import almost all of the 3.0 features in 2.6 on a file-by-file basis. So you can pretty much write code in Python 2.6 as if it was 3.0 provided you do the necessary "from __future__ import XXX" at the top of your file to do things like make "print" a function rather than a language keyword, etc. You won't have the reorganized standard library, but for most tasks there's either no difference or minor differences.

So yes, definitely learn Python, but be sure to install both 2.6 and 3.0. I recommend learning with 3.0, but you may have to do "real" projects in 2.6 for some time.

mechanical_fish• 18 years ago

from __future__ import XXX

"I'll borrow features from myself in the future!"

[time passes]

"Hey! That guy from the past just copied all my features!"

pavelludiq• 18 years ago

I love Py3k

bdr2• 18 years ago

I'm ambivalent about changing so many functions to return iterators. It's cleaner for experienced coders, but harder to understand for beginners.

dnaquin• 18 years ago

Most of those changes get masked behind loops that I don't think either is very different for understanding.

I think the plusses outweigh the edge cases.

bdr2• 18 years ago

Having taught a couple beginners, I can tell you that what you see when you print a variable is very important. So, I guess it depends how these objects convert to strs, but I was assuming it would show a zip or map object rather than the result.

schtog• 18 years ago

what are the edge cases? what are the advantages of iterators? less memoryuse?

rbanffy4• 18 years ago

I loved it, but I still want better threading and multi-core support in CPython... Most desktops now have two cores and it doesn't seem likely that number will fall anytime soon...

marcher2• 18 years ago

Python 2.6 and 3.0 ship with a new library called multiprocessing which provides mechanisms for process control and intercommunication, which conveniently sidesteps the GIL limitation that prevents multiple core usage.

The library is loosely based around the existing threading API, and allows for seamless transfer of Python objects between processes (unlike other forms of IPC).

rbanffy4• 18 years ago

I know. The library is available to 2.5 as "processing", but starting OS processes when all you wanted were threads is somewhat ugly. I agree it's not possible to do it properly with the GIL in place and attempts to remove it did have less than amazing results on single-thread applications.

That's annoying... Even more annoying when I think it's easier to do in Java ;-)

illume• 18 years ago

Not so seemless. Things need to be serialised to transfer them. You need to specially craft code so that it is pickle safe... things don't just work automatically.

Also serialising 100MB or so worth of objects around is really slow. So the process module is not good for many cases of use.

cpr3• 18 years ago

Guido (BDFL) has said that the GIL will not be removed in 3.x, so we'll have to look for other implementations to tackle this problem head-on. As someone else remarked, there's a new multiprocessing library that attempts to make this more palatable.

lunchbox2• 18 years ago

The download link for Python 3.0 is now featured prominently on the front page, above Python 2.6. I think this is a bad move, since many Python newbies will probably download Python 3.0 instead of 2.6, and then get frustrated when none of their 3rd-party packages work. python.org should keep Python 3.0 more hidden away for the time being to give time for the greater Python development community to migrate to 3.0.

babo• 18 years ago

A base python installation is good enough for most of the tasks for a newbie. Python 3.0 is out in a quite stable form for early migration testing, it's not as bad as you describe.

cpr3• 18 years ago

Babo's right--remember that Python is "batteries included," which means all the standard libraries (which cover a huge range of uses) are already 3.0-ized.

lunchbox2• 18 years ago

Good point. But http://www.python.org/download/ says in its discussion of 2.6/3.0: "if you don't know which version to use, start with Python 2.6." To me, this advice is inconsistent with the layout on the front page, since most people who don't know what to use will click on the 3.0 link.

stillmotion• 18 years ago

Wow, even the introduction is incredible.

"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."

I have never seen a release for a new language be so clear and straightforward. That's awesome.

omouse• 18 years ago

What about Scheme R6RS?

http://www.r6rs.org/final/html/r6rs/r6rs-Z-H-1.html

The report gives a defining description of the programming language Scheme. Scheme is a statically scoped and properly tail-recursive dialect of the Lisp programming language invented by Guy Lewis Steele Jr. and Gerald Jay Sussman. It was designed to have an exceptionally clear and simple semantics and few different ways to form expressions. A wide variety of programming paradigms, including functional, imperative, and message passing styles, find convenient expression in Scheme.

fh• 18 years ago

For one thing, the quoted paragraph doesn't explain what they changed in R6.

nihilocrat2• 18 years ago

Now the question is: when is Stackless Python going to go 3.0?

goldenpotter• 17 years ago

If I install the 3.0 package on Ubuntu, will the "python" shell command be forced to 3.0? In other words, what are the basics of doing and using a dual 2.x/3.0 installation? -goldie

Python 3.0 Released

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