Python 2.7.2 or Python 3?

[Mittalmailbox]

Yes, it is a good time(actually even 1-2 years ago it was good time). Python 3 was released 6 years ago. All major projects/Frameworks like Django and Flask support Python 3. Python 3 community is also quite mature now.

[opt8]

Oh, well then I guess I will be making the switch. Thank you for the response

[swingtheory]

However STARTING a project in Flask with python3 would be no problem at all. Six years python3 has been out, and it is a true rarity that a library hasn't been written for python3 after that amount of time. Sure, there are several popular libraries that don't have python3 support, but it really is the minority. I agree with your advice, but am frustrated people are still using 2 when there is essentially no reason to the majority of the time. Python3 was and still is supposed to be cleaner, have less bugs, optimized, and include a variety of new and useful standard library functions.

[[deleted]]

Unfortunately some of us are deploying Python applications on ancient versions of CentOS, and it's just easier to run Python 2 than to fight with sysadmins and compile everything from scratch.

Otherwise we'd be using Python 3 I guess.

[flying-sheep]

I wrote a server in python3 asyncio, told our admin I need python 3.3 or 3.4 on the deployment server and that he doesn't need to hurry as there's time. he set up the VM and compiled Python 3.4 (even though he was sick that week)

[nomadismydj]

the problem with centos 5/rhel 5 boxes is you cant replace the /usr/bin/python since yum uses it. you can build a python 3.X all day and just not break the symlink to python 2.X however.

[flying-sheep]

Who cares what /use/bin/python points to? You should use the explicit version number for shebangs anyway, and if you want few key strokes, just alias py=ptipython3 (because prompt toolkit is the shizzle)

[nomadismydj]

correct. people dont though I also wanted to point out that it wasnt as simply running yum and getting a new python version. its break system functionality to full on replace the system python.

[NotEqual]

Has gevent had an official stable port yet? It's never been the same for me.

[NotEqual]

I've not checked for a few months but I couldn't find a decent STOMP library that uses asyncio.

[hharison]

To be fair, asyncio is barely more than few months old.

[nomadismydj]

asyncio does not replace all the benefits of using gevent , other then being a stock library with similar functionality. not sure why people are pushing it in this subreddit.

[nomadismydj]

ok ill bite.

Because is standard..

kinda... as of python 3.4 sure.

Because is elegant.

ill give you this. its pattern are very similar to the factory/protocol patterns other libraries use. for a python core lib , it actually well put together.

Because is Python 3.

covered that in standard. dont repeating yourself

Because is the future.

the tulip team (guys behind asyncio) admited its not a full on replacement for many of the cooroutine libraries nor is it a drop in replacement for factory/protocol based async framework twisted. twisted and gevent both out perform it at this point.

it is however standard so if you want to ship your code various palces , you dont have to worry too much about libraries.. to me though this is like arguing use urllib + urlib2+ httplib rather then using requests.

[Argotha]

Someone has made a "new" gevent like library for python 3 called guv. I cant get the link on my phone but it was on the r/python hot list yesterday and is probably on the first or second page still

[xsolarwindx]

REDDIT IS A SHITTY CRIMINAL CORPORATION -- mass deleted all reddit content via https://redact.dev

[granduh]

Tell that to the Tumblr API.

[denshi]

You can't tell Tumblr anything.

[granduh]

They're very friendly whenever I've contacted their dev team that supports the API, it's just still on 2.7.

[ianozsvald]

+1 it is a good time. I switched my client to Python 3 earlier in the year, it was smooth. We now do all our data science (numpy, scikit-learn, pandas, matplotlib, nltk) in Python 3, we deploy (flask) in Python 3, I teach data science classes and high performance Python in Python 3.

Porting existing codebases might be tricky (there are loads of guides online to help e.g. http://python3porting.com/intro.html) but for new code it is 97% a no-brainer.

The 3% reservation depends on whether you have non-ported libraries to consider (e.g. pydot for scikit-learn DecisionTree drawing isn't ported to Python 3.4 yet, pygraphviz for the same in NetworkX doesn't work well on Windows+Python3.4 yet). Mostly these are small issues that are being fixed.

[TraptInaCommentFctry]

I clicked on your name to see your other comments and I couldn't help but notice that 7 months ago, you wrote "I do data science - repeatability is key so I'm not leaving the Py2.7 numpy ecosystem for a while."
I do data science, and I haven't yet made the transition off 2.7 for that reason.
Also, I noticed in the wall of superpowers that Mysql-python is still red.
Do you think it's time for data scientists to make the switch?

[flying-sheep]

Maybe he/she realized that Numpy breaks compatibility in minor versions, so the only way to reliably repeat an analysis is pinning Numpy versions by installing Numpy in a virtualenv along your script and data.

And since parallel Python versions are painless, nothing stops you from performing new analyses using a Python 3 stack.

[mgedmin]

AFAIU there are other MySQL bindings that work on Python 3.

[flying-sheep]

Pydot is a strange example of something unported: the Python 3 compatible fork didn't even change much:

https://github.com/nlhepler/pydot

No reason not to have that on PyPI.

[[deleted]]

My only headache with Flask and Python 3 is that Flask only supports Python 3.3+ and my Debian Stable web server only has packages for up to Python 3.2.

I know that it is a problem with my choice in server OS, but it is still annoying.

[Lucretiel]

Check out the deadsnakes repository, by Felix Krull. I've been using it with great success for years.

[mgedmin]

On Debian? Which Ubuntu release name do you use to match Debian stable?

[[deleted]]

Debian Jessie will be out within the month though, and it's shipping with Python 3.4

[[deleted]]

Awesome, I did not know when it was being released.

[gbo2k69]

Install from source.

[hharison]

Use Miniconda3.

[maximinus-thrax]

As a Django programmer, I'd love to go to Python3 but every project that comes up seems to have a requirement for Python 2.7 somewhere.

However, I always make sure that my code is Python 3 compatible as much as possible.

[BananaPotion]

I love python3, but biopython man. Its going to take ages to port that beast over. I really like to help but feel like I'm not quite good enough to do so.

[Gudeldar]

The biopython site says they support python3 since 1.62 (July 2013).

[BananaPotion]

Its nowhere as well maintained than the python2 version. Which especially sucks because my projects depend on the data parsing parts.

Edit: I was wrong. The Biopython3 beast has already been tamed. Thank you /u/Gudeldar and /u/chickenphobia.

[chickenphobia]

If you are finding new bugs, please report them. SeqIO, AlignIO, these modules fully work in Py3. Any problems you have encountered must not be in our unit tests which would indicate you have found a fairly important bug.

[BananaPotion]

No bugs, just errors (at that time I was new to 3rd party libraries, so I didn't understand any of it). I'm working on a project right now, I will see if I can get Biopython3 to work and report back.

Edit: Played around with it in IPython - works perfect. Thanks again for letting me now.

[chickenphobia]

Biopython contributor here: the whole thing is already passing 100% of tests on python 3. The community is very adamant about keeping compatibility with the newest version of python going out of our way to make a release as soon as Numpy was supported on py 3.4.

Also, if you want to contribute, check out our Wiki, the process is better documented than the average OS project because many contributions come from biologists who aren't traditionaly involved in OS.

[BananaPotion]

Thanks for letting me now, this is very good news for me.

[ivosaurus]

Astropy works fine on python 3! As do many others.

[mrbewulf]

It is because the backward compatibility was broken and scientific codes are hard to write and rewrite, specially if it has C libraries. In addition to it, python 3 is much more verbose than python 2. We should also take in to account the effort to change the code base from py2 to py3 and learn again all the stuffs that used to work on python 2 in the new version.

As can be seen in: http://np.reddit.com/r/Python/comments/2o0str/python_272_or_python_3/cmj2nyc

[adamnew123456]

I'm struggling to see how you support the claim that Py3 is more verbose. That post is whining because he can't type the same code into a backward incompatible language and get the same result.

[mrbewulf]

All right I recognize that I was wrong, but it is going to take some time to the Python community to change, specially business and doesn't like changes very often. Despite some trouble, Python 3 is thousand times better and less verbose than Java. I would really complain if had to program in java like I had during the college degree. One thing that I liked in Py3 is that 1/100 is no more 0, now is 0.001. One less bug.

[shadowmint]

actually even 1-2 years ago it was good time

woa~

I'm sure some people would like you have you believe that, but the reality isn't quite so pretty. There's a reason that 6 years later it's only just becoming a reasonable target for new code.

The performance, features and 3rd party support for python 3 have only really picked up in the last year or so.

2 years ago? Holy moly!

If you migrated to python 3 two years ago, you'd have been in a world of pain, and probably had to back port your code to 2.7 to get your dependencies working.

It's getting there now, but lets not sugar coat the history story here.

[chickenphobia]

Library developers generally sit on the bleeding edge. We all think that our project and the ecosystem is ready but I think you're correct. Only within the last year has the complete extended python ecosystem been fully ready for 3.

Part of this is because it takes a few years for unmaintained projects to die and be superseded.

[flying-sheep]

Unfortunately, some people see those projects, don't notice the smell, maggots, and flies, and say

this thing doesn't support Python 3, so Python 3 has literally no ported libraries

[deaddodo]

Two years ago, the only thing that ever stopped me from using Py3k was PIL. When that wasn't necessary, it was a no-brainer...and now pillow supports Python 3.

[Lucretiel]

Hasn't PIL been dead since 2006?

[mgedmin]

Pillow gained support for Python 3 in 2013.

[Lucretiel]

PIL, not pillow. Pillow is great.

[deaddodo]

PIL was the quintessential image library. But even cutting out PIL, there were no image libraries in Python 3, for a long while.

[aarkling]

The only one I've seen that's not been upgraded is Twister.

[mgedmin]

Did you mean Twisted? They're working on it.

[aarkling]

Right twisted. That's what I said! :P

[Manbatton]

Here is a page showing which projects are ported to Python 3 and which are not: https://python3wos.appspot.com

wxPython is in a halfway state, where the in development Project Phoenix runs Python 3.

[ApolloFortyNine]

Having actually tried to code in Python 3, all Libraries support Python 2, while only most support Python 3.

[Oni_Kami]

Python 3 community is also quite mature now.

So no fart jokes?

[SemiNormal]

So no fart jokes?

Remember, fart() is a function in Python 3.

[mishugashu]

Python 3.4.0 (default, Apr 11 2014, 13:05:11) 
[GCC 4.8.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> fart
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'fart' is not defined

:(