Python 3.4.0 released

https://www.python.org/download/releases/3.4.0/

by jvm • 12 years ago

280 135 12 years ago

python.org

Watabou2• 12 years ago

Wow, pip bundled by default. Very interesting.

rectangletangle2• 12 years ago

Having pip and venv bundled with the standard distribution is convenient.

Watabou2• 12 years ago

Yeah, I'm hoping this will make it easier for people to upgrade to python 3.

tachion• 12 years ago

Doesnt including those in distribution slows the pace at which they'll be developed and released?

baq• 12 years ago

this, unicode and exceptions are IMHO good enough to start thinking about upgrading. you might say that pip is a non-issue because everybody who develops in python has it installed anyway, but in windows world deploying python apps has always been a pain (yes, i use py2exe, it's not perfect).

raverbashing5• 12 years ago

No, the Pip issue is huge

This makes a proper P3 Virtualenv into something good (from something barely ok in 3.3 where you need to install setuptools manually in your virtualenv)

unfamiliar2• 12 years ago

Is pip actually included by default, or just an installer for pip?

donaldstufft2• 12 years ago

Both kind of!

Added to the stdlib was "ensurepip", which is a simple installer for pip. The ensurepip module includes inside of it a copy of pip that it will install from (in other words, ensurepip doesn't hit the network).

There are various reasons why it does this, part of which is to enable easy upgrades to newer versions of pip both inside of CPython itself, and for the end user to upgrade it locally.

gangster_dave2• 12 years ago

Cool. I love Python, but it's really going to be a decade before this interpreter is used in production by anyone.

broodbucket2• 12 years ago

Python 3 came out in 2008. You're saying 16 years post-release until a moderately sized change (the majority of which is regarded as improvements) to a language is used in production.

That's totally bonkers.

levosmetalo• 12 years ago

And people complain about slow Java upgrade cycles ;)

kamaal• 12 years ago

>That's totally bonkers.

Actually its not. No one will want to spend time and effort on regression just because the tool maintainers want a print statement to be function and not a statement. Or for a small trivial change.

rectangletangle2• 12 years ago

I think adoption will improve substantially when major Linux distros start shipping with Python 3.x as the default interpreter. I believe this is the case with Ubuntu 14.04 LTS.

kintamanimatt6• 12 years ago

Major Linux distros already do.

gangster_dave2• 12 years ago

If you're code is still locked to 2.7, what your OS ships with doesn't matter.

thomasahle• 12 years ago

I find it hard to think of anything that doesn't run on Python3 by now. The only thing that's still good about Python2 is that it's much faster. I always hope for a release that addresses that.

kintamanimatt6• 12 years ago

Twisted and gevent don't!

buovjaga• 12 years ago

This things lists Python3 support in PyPI packages: http://python3wos.appspot.com/

rhizome312• 12 years ago

Do you have more info about how Python 2 is faster than Python 3? I had understood that it was faster for some stuff but slower for other stuff. This benchmark says they're roughly the same: https://speakerdeck.com/pyconslides/python-3-dot-3-trust-me-...

epsylon• 12 years ago

There's plenty of stuff that still run on Python 2 these days. Google App Engine, for example, is still Python 2.7 only.

goostavos• 12 years ago

WxPython =( Which is, like, 90% of what I do at work. I really want to upgrade to 3, but alas... Still stuck on 2x.

lambda3• 12 years ago

Twisted is a pretty big dependency. The entire stack that I work on depends heavily on Twisted, and we use a lot of it, so until it's ready on Pyhon 3, it'll be hard for us to move.

We also depend on Paramiko, which is also red on the WOS.

kilink• 12 years ago

Boto doesn't support Python 3 yet. That's a pretty big one if you're using AWS.

anewhnaccount• 12 years ago

The problem with statements like these is people always move the goal posts. If challenged it goes from nobody to talking about the proportions. There are plenty of people who will use this straight away. Yes, maybe as a proportion but Python has a lot of users developing a lot of different types of applications. Even if initially it's a small proportion, it's not the absolute numbers are large. I guess some of the bellyaching is because there's a feeling that the community and ecosystem of libraries is becoming fragmented -- but the community is large enough to take it and anyone really needing a particular library should be capable of expending the effort to port it or find an alternative. There are plenty of users who don't engage with the community much and/or just use established libraries/the standard library anyway.

In conclusion, not everyone is in the same boat as you. Try and see beyond your own nose pleas.

saurik• 12 years ago

I imagine some of the disappointment is that there is a large community of people using the language ecosystem "Python 2", and that ecosystem seemed to have been prematurely killed in the hope of not just helping the small proportion of people who considered this new language ecosystem "Python 3" valuable, but seemingly in a failed attempt to actively strongarm people into switching: it's like if the people who worked on C++ standardized Rust as "C++14" and indicated that not only were no language inprovements ever coming to the old C++, but that all of the compiler implementaters had given up on it and were unlikely to ever release updates, even to fix bugs: that if people wanted support from the language called "C++" they needed to switch to this new language ecosystem. Sure, the syntax disparity is much smaller between Python 2 and Python 3, but the library semantics are still highly skewed (I mean, if it were just some simple syntax issues everything would have been trivial to port immediately). But really, the key issue is really the language ecosystem: the number of available libraries, the distribution in major operating systems, the cloud hosting options, etc. While these almost look vaguely hopeful for the Python 3 crowd at this point, it took five years of enforced death of Python 2 to strongarm it to even this point, and as it stands it is still weak. Maybe after 5 years of enforced death to C++ compilers someone could also claim a transition to Rust looked hopeful. And again: I understand that for some people this is great: I don't think anyone is actively complaining that Python 3 shouldn't exist, more that it's existence at the detriment of Python 2 snubbed a very large community of people. Like, one could say the same thing to the people who advocate everyone upgrading ASAP, or even ever: "not everyone is in the same boat as you; try to see beyond your own nose please".

ubernostrum• 12 years ago

I'm already using 3.3 on live stuff. Likely to make the jump to 3.4 when I have the time to do the upgrade.

chrismonsanto• 12 years ago

I will be using Python 3.4 in production soon.

chris_mahan2• 12 years ago

I use python3 in production. Working at large bank.

illumen5• 12 years ago

Nice one :)

If there's anyone not using python3 in production now, I'd be wary of that team. Maybe it could be forgiven two years ago, but now... There's just too much to be gained with modern python.

But hey, there's still some organisations using php3 in production!

deckiedan• 12 years ago

Funny, the pathlib functionality is really similar to a saturday morning hack that I was playing with a few months ago.

Pathlib, asyncio, unicode default, bundled pip and venv...

I do like the look of Python3. It's looking a lot more interesting, the further along it gets. I still haven't really done anything with it, due to python2 being bundled with our OSX and Linux workstations, which means painless installs. This year, however, I do want to start porting my projects over to Python3 (well, making them run on both, at least...)

agumonkey2• 12 years ago

What surprised me is that after a long time with string based path libs, Java and Python are now moving onto oo based ones. I wonder how many other languages already had abstractions for this (smalltalk ? ruby?).

rjbwork• 12 years ago

C#/.NET/PowerShell has some decent path abstractions. You still usually create the initial object via a string at some point though...

est• 12 years ago

I wonder how many other languages already had abstractions for this (smalltalk ? ruby?).

I remember VBScript/JScript with FileSystemObject decades ago. It's from COM

draegtun• 12 years ago

Perl comes with File::Spec since 1999 (perl 5.004_05) - http://perldoc.perl.org/File/Spec.html

NB. And there are more full featured alternatives on CPAN like Path::Class (https://metacpan.org/pod/Path::Class), IO::All (https://metacpan.org/release/IO-All) and Path::Tiny (https://metacpan.org/pod/Path::Tiny).

Rebol has its own file datatype which works seamlessly across platforms - http://www.rebol.com/r3/docs/datatypes/file.html | http://www.rebol.com/docs/core23/rebolcore-12.html

raverbashing5• 12 years ago

What I'm glad is that apparently they did a good job in converting it, and not converting it to OO just for the sake of it and resulting in a crappy API "but it's OO"

rnnr• 12 years ago

It had been proposed various times in the past and it was rejected.

I don't remember the semantics of the reasons it was rejected, but if you search about 'pep' and object paths you ll find more info

brownbat• 12 years ago

Do the docs worry you?

"Note This module has been included in the standard library on a provisional basis. Backwards incompatible changes (up to and including removal of the package) may occur if deemed necessary by the core developers."

http://docs.python.org/3.4/library/pathlib.html

wtbob• 12 years ago

Common Lisp has had object-based pathnames, as well as namestrings for over two decades now.

gnur• 12 years ago

Asyncio sounds promising, does anyone with more knowledge know whether it comes close to Go channels?

Go channels are the only experience I have with concurrent programming, but when I understood them it quickly became second nature to create everything using channels. Can techniques like websockets be used now as cleanly as in Go?

DanWaterworth• 12 years ago

I've been using asyncio in the last week. I've found it remarkable clean and intuitive. It's difficult to compare to channels in go, because it's such a different solution to the same problem - that of structuring concurrent programs.

babarock3• 12 years ago

If anyone's interested in testing out Asyncio/Tulip on Python 2, here's a mostly-compatible backport: https://pypi.python.org/pypi/trollius/

dalke• 12 years ago

They aren't like channels. If you want something like channels, try out greenlets for CPython, Stackless Python (a modified version of CPython) or pypy.

nostrademons• 12 years ago

I suspect that you could easily implement channels on top of asyncio - goroutines = coroutines, hide the yield-from inside 'send', select = asyncio.wait(return_when=FIRST_COMPLETED).

waitingkuo• 12 years ago

It's time for me to switch to python3! btw, I can't wait for the matrix multiplication operator which might be released in python3.5.

rhizome312• 12 years ago

Nice to see single-dispatch generic functions coming to the standard library. That will help making some pieces of code simpler and more readable.

babarock3• 12 years ago

Here's a good explanation of this technique: http://julien.danjou.info/blog/2013/python-3.4-single-dispat...

ubertaco• 12 years ago

Nice! That's something I like about Haskell and Elixir: the ability to define behavior for a given case. Though it looks like that's constrained to type-based dispatch (a la Java method overloading). Is there any way to define for specific values?

bcoates• 12 years ago

If I understand the PEP right, this explanation is missing the part where it's only useful to extend abstract classes; python classes are open so you can just add a method to a concrete class to get single-dispatch if that's all you need. I don't think the example given needs generics at all.

nichochar• 12 years ago

That statistics module makes me happy too

MisterMashable• 12 years ago

...and Google App Engine still uses 2.7

pfalke2• 12 years ago

Are any plans for Python 3.x on GAE known?

Speculation: A Python 3.x runtime might be the mystery annoucement promised for the Google Cloud Platform Live event on March 25. Unless it's a Node runtime?

tbatterii2• 12 years ago

my $$ is on a node runtime, assuming google is interested in increasing the # of people that use it. python 3 would be nice but it probably wont get people interested like node would.

agentultra• 12 years ago

Glad to see customizable memory allocators made it in. Now if we could only take it up a notch and allow the run time to assign custom allocators on individual objects I could implement something like CCL's WATCH [0] for Python objects which would make debugging multi-threaded code much easier.

Congrats to the python-core team and thanks to everyone for another great release!

[0] http://ccl.clozure.com/ccl-documentation.html#watched-object...

illumen5• 12 years ago

tldr; 'watchpoints' in python can do this already(since before clojure existed), but it's not built into standard pdb.

You could do the allocator yourself with a custom allocator easily. Just inspect the object type or object id, and in your meta allocator select the correct allocator.

I'm not sure how that would help you with a CCL style WATCH though...

pdb, with set_trace or conditions on breakpoints could let you WATCH individual objects. Search google for watchpoints.

cschmidt4• 12 years ago

It makes me slightly sad that the median routine just sorts the data, and looks at the middle. I was hoping for quickselect, which uses 4N comparisons in the average case.

http://www.ics.uci.edu/~eppstein/161/960125.html

or maybe Blum, Floyd, Pratt, Rivest, and Tarjan if you're being fancy, which is 24N comparisons in the worst case (but more than 4N for the average case).

http://www.ics.uci.edu/~eppstein/161/960130.html

schmichael2• 12 years ago

I'm sure patches would be accepted as there's no reason the implementation of the function has to remain identical over releases.

cschmidt4• 12 years ago

I haven't got time at the moment, but I would consider contributing an implementation in the long run, if no one else does by then. It just shouldn't be O(n log(n)) when it doesn't have to be.

fnbr2• 12 years ago

This might be a stupid question, but would you know where the the source for the statistics module can be found? I would be quite interested in submitting a patch, but I can't seem to find the source.

naftaliharris• 12 years ago

A few months ago I wrote a C implementation of a lazy "sorted" function, (https://github.com/naftaliharris/lazysort). One of the things you can use it for is computing medians, with the same "sort-then-take-the-middle-element" algorithm that the statistics module uses. Internally, however, what will happen is that the lazy data-structure that results from a call to the lazy "sorted" function will find the middle element with quickselect.

For lists of size 10M, I got a 7.3x speedup vs using the sorted function, and a 1.6x speedup vs using numpy.median. The sorted function was faster up until lists of size 100, presumably due to lower overhead. (The lazily-sorted list data-structure also keeps track of the pivots resulting from partitions, so that later method calls run faster by exploiting the partially-sorted structure that remains from earlier method calls).

Here's a plot of the time to compute the median for these different algorithms, (taken from a paper I wrote that's under review): http://imgur.com/oX1QLnS

ajanuary• 12 years ago

Tangential observation: most implementations of quickselect to find the median I've seen use 6N comparisons in the average case; for an even length list they select the middle values using two independent quickselects. The code to do it in a single quickselect gets hairy quite quickly.

andlima• 12 years ago

There's a comment about that over there: "# FIXME: investigate ways to calculate medians without sorting? Quickselect?"

http://hg.python.org/cpython/file/3.4/Lib/statistics.py (line 296)

unfamiliar2• 12 years ago

The whole statistics module seems very minimal to me, I was hoping for it to include distributions and random number generators etc. but it only includes a few very basic functions, and not even the best implementation of them. Hopefully it will expand in future releases, but I don't really see the point of including it with such limited functionality.

maxerickson2• 12 years ago

I think it intentionally started with things that people would tend to implement slightly incorrectly (rather than reaching for a 3rd party library).

dagw2• 12 years ago

People who need distributions and more advanced features probably want numpy anyway, which already has all of that. This just covers the very basics that people might run into while doing 'normal' non-statistical programming.

ggchappell• 12 years ago

Or maybe Introselect, which does Quickselect, but switches to Median-of-Medians (i.e., BFPRT) if the recursion depth gets too big. It has the average-case performance of Quickselect, but, like M-of-M, requires only O(n) comparisons when given a list of length n.

adidash• 12 years ago

So is Python 3.4 a good starting option for a newbie to learn coding or should I stick to 2.7 considering all the courses are still using 2.7?

mildtrepidation2• 12 years ago

That depends. If you intend to work on other people's code or currently-active projects (or anything likely to be active soon), starting with 2.7 and learning the differences later would be a good approach.

If you're just using it for its own sake, or only for building things locally that either don't need to run anywhere else or only need to run where you have enough control to install your own Python, and you don't and won't need dependencies that aren't currently ported... then definitely start with 3.x. :)

e1ven• 12 years ago

I find 3.4 much easier to use, personally.

I've written several production apps in it, and the unicode fixes in particular are a much easier, as well as little things like being able to do enums.

Ultimately, they really aren't all that different- I think the differences tend to be overblown somewhat on HN.

If the course/teacher you like only teaches using 2.7, learn that. You can pick up the changes from 2.7->3.4 on your own pretty easily once you know the basic language.

takeda• 12 years ago

Yes, there's nothing you will gain by starting with 2.7. The language is polished, majority of modules are ported (currently from those that matter only twisted and opencv isn't).

If you for some reason have to work on older version (for example RedHat still uses 2.6) knowing Py3 is not really an issue to program there. Of course few nice features are missing, but people seem to talk as if it is a completely different language for some reason. With Python 3 at least you have a nice more consistent language.

If you were learning Java, would you start with JDK 1.3 or the latest one?

yizzerin• 12 years ago

There's very little difference between the two (a few standard library differences at most + a little syntax). 3.4 (and Python 3 generally) is the future of Python. Learn it first and you'll be on good footing.

DonGateley• 12 years ago

When there's a release with a bullet item saying "Full compatibility with 2.7 libraries" I'll get interested.

JoachimS• 12 years ago

Good to see that the internal hash function has been replaced with SipHash. It took quite a while for Python to decide to not try to tweak their own hash function/PRF. Now Python is on par with Ruby and Perl.

http://legacy.python.org/dev/peps/pep-0456/

Python 3.4.0 released

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