So, as someone just dipping their toes into Python, what did you do regarding 2 vs 3? I have been tinkering with 2 but should I go wholly with 3? Help me before I just go back to Perl 5... :)
Learn Python 2 first, since it's vastly more supported right now, but know that it's very easy to jump between Python 2 and Python 3, and many people do. The decision of which to use on any particular project is basically:
1. Are you doing web development? If so, use Python 2.
2. If not, do you need or want to use PyPy? If so, use Python 2.
3. If not, are the libraries you want available for Python 3? If so, use Python 3.
4. Otherwise, use Python 2.
You know, I hate to say it, but you, and your parent commenters have basically said quite a bit without actually answering the question. Anyone coming here wondering which one to learn is going to be left with the same question, only slightly more confused.
I purposefully avoided any attempt to answer the question directly.
How would one know what to recommend while knowing nothing about `jcurbo`s intentions/designs/requirements?
The stackoverflow and wikipedia communities sometimes get flack about maintaining strict objectivity, and I know the HN community is allowed to be different, but surely you agree that there is no right answer to `jcurbo`s question. And if there is no right answer, surely offering information from a trusted source can be just as helpful (if not moreso).
> How would one know what to recommend while knowing nothing about `jcurbo`s intentions/designs/requirements?
For someone learning Python? Just give them your best suggestion. Look, it's fairly easy.
Learn Python 3. There are differences, and you might run into issues later on, but once you get to that point, you'll know enough to do something about it.
See, when someone asks whether to learn Python 2 or Python 3, that's what they are asking for. If they are learning for specific reasons (for a job, lets say), then instead of trying to answer, you ask follow up questions. But for learning a language, they are seeking advice from experienced people.
So, when those same experienced people, who already know Python 2 and/or Python 3 tell them to learn Python 2 and/or Python 3, they are being told: we don't know.
And how is someone inexperienced supposed to know which one to learn when experienced people don't know?
Basically, if you can't answer the question because you feel you lack information, ask. Otherwise, answering the question "Learn Python 2 or 3?" with the answer "Learn Python 2 or 3." isn't helpful.
Thanks to you and everyone else that responded. I was more interested in the parent's actual experience, what made them frustrated, etc. I agree that it depends highly on personal use cases and what you are trying to do. Personally, I am using it to support some of my graduate studies and some personal projects, nothing major. If I was doing major software development I would be doing more research on my own, and indeed this line from the wiki page would seal the deal for me:
"At the time of writing (July 4, 2010), the final 2.7 release is out, with a statement of extended support for this end-of-life release. The 2.x branch will see no new major releases after that."
Since what I am working on doesn't involve major libraries (like numpy) I see no reason to stay on 2.x and I think I'm safe to look at 3.x for future stuff.
It almost always is. The term has a connotation of "the existing state of affairs for the majority of people". So the majority of the web is largely template driven web pages/apps, served from php or java or maybe python behind apache, with some stuff enhanced by javascript. That is the status quo. All of us here of course know that is largely going to go away (and it's actively even happeninge), replaced by javscript driven single page apps where templating happens client side, and the web server becomes a file transfer mechanism for the code and some data, a well tested way of doing rpc for the rest of the data.
So yes, there are pages doing this new style web right now, but that doesn't change that the mojority of web stuff is the older style. So yeah, the current state of affairs is that the web is mostly outdated.
This is necessarily true always, unless that which is being examined is stagnant.
So, as someone just dipping their toes into Python, what did you do regarding 2 vs 3?
As someone who was learning Python for fun personal projects rather than serious business projects, I decided to use Python 3 wherever possible, while familiarizing myself with Python 2.7 just in case. It turns out the two versions really aren't all that different. A lot of people will still recommend starting with Python 2.7, since it really is such a small jump from there to using Py3k; I essentially did the opposite. Both approaches work. Finding tooling for Python 3 might still be a challenge (I remember having to fix one or two bugs in IPython before it would run at all), and the usefulness of these tools to a beginner is really the biggest reason why you might want to stick with 2.7 for the moment. But if you're adventurous, I do highly recommend Py3k. Especially with the upcoming 3.3 release (due later this year), I'd argue that Python 3 finally has enough new features (and enough library support) to justify using it full-time.
(When will it be possible to know, beyond doubt, that Python 3 is ready for prime time? When third-party implementations like PyPy and Jython make the jump. I don't know about Jython (which just recently made it to 2.7), but PyPy's working on it as we speak.)
Unless you need a library that's only available in 2, I'd use 3 at this point. But virtualenv takes the pain away from having to choose, since you can just create a new "environment" with 2 or 3 depending upon your needs for a project.
If you're coming from the Ruby scene, think of virtualenv as Python's take on RVM.
As a beginner, picking between 2 or 3 should not be one of your concerns, it's a choice that does not unlock much value either way (and it does not hurt much if you pick the 'wrong' way either).
I would say start on 2.7, as most of the popular Python libraries are still Python 2.x only, and 2.7 backports some Python 3 features, so you (and your code) will be ready for 3 whenever the world switches over :)
Python 3 was on a 5-year transition. This was to let the tools develop, give time for major libraries to be ported, etc. We are now more than halfway through, so most of the important libs work fine in Py3. And the syntax is generally nicer, so you might as well start with Py3 today.
Zed Shaw originally strongly advised students in his Learn Python the Hard Way course to go with Python 2, because there's less opportunity for confusion (eg, if you start with 3 there's a good chance you'll come across libs you need that haven't been ported to it yet).
However, I can't find that warning anymore in the second edition, so not sure if he's changed his mind or not.
Learn Python 3, it has nice new language features and some of the hairy parts of older versions have been replaced with new and consistent constructs.
If you need to ship and launch a software that absolutely depends on libraries that only work with Python 2, it should be rather easy to not use the newer features and go with Python 2.
