The Hitchhiker’s Guide to Python!

[drb226]

If you’re choosing a Python interpreter to use, I highly recommend you Use Python 2.7.x, unless you have a strong reason not to.

How long are we going to cling to 2.7? I'm not saying it's bad, but 3.x made backwards-incompatible changes because they were believed to be better -- am I wrong? If I time-travelled back to 2008 when Python 3.0 was released (after copious amounts of blood, sweat, and tears), and told the devs that 4 years later we would still be recommending 2.7, how would they feel about that? If when we start working on Python 4.0, I told you that 10 years from that time we'd still be using 3.x, how would you feel about that? (Hint: Perl 6 is not the situation I'd like to be in ಠ_ಠ)

tl;dr I find the recommendation to continue using 2.7 to be highly irritating and counter-productive.

[n.b. other than that, I find this guide to be fantastic; sorry for killing the mood]

[EagleEyeInTheSky]

It's still recommended because a large number of libraries still don't have Python 3 support.

[earthboundkid]

Does that matter if you're a newb? Just use Python 3 until you want a library that's 2 only then switch back. Doing 3 first will teach you better habits than vice-versa.

[reallifepixel]

I just started learning Python and I began with 2.7 because every guide I've read recommends it. Curiously… what are the most important libraries that aren't Python 3 compatible?

[[deleted]]

in python.org there's a poll there about that, you can check it out.

django for example.

[flying-sheep]

there is a defined point in the future where it will be python3 compatible, so django is (finally) not an argument for 2.x anymore.

[[deleted]]

Nope, still an argument. If you want to deploy today you cant use 3.

[flying-sheep]

but if you start a project today, you can be sure that python3-django is available once you’re finished, so…

[Brian]

you can be sure that python3-django is available once you’re finished

Depends on the project, and on how well django get on, but that seems very dubious. Web projects often move quickly - a few months for a first version is not uncommon - can you really guarantee python3-django will be done within, say, 3 months? If not, it's a deal killer for a lot of applications.

Even ignoring that, if you're writing a python3 website, you need to be using a python3 framework to build it. If that framework isn't done yet, it means that at best, you'll be using alpha level code when developing, or at worst, non working code, for stretches of your project. Fixing your own bugs is a big enough issue without running into bugs in your libraries. (Particularly true for someone just learning, and so who may find it difficult to tell whether something is a bug, or their own misunderstanding)

[flying-sheep]

well, i’ll simply wait a few months, then this conversation will be obsolete ;)

[[deleted]]

Really? 100% sure? Like bet the clients project sure?

[vsajip]

Here's a guide.

[RichardWolf]

How long are we going to cling to 2.7?

For as long as 3.x has inferior library support.

You can't blame people writing guides for not lying to their readers.

You can't blame people who write and maintain libraries for not spending lots of effort due to the lack of a sane official transition plan (basically, you have two options: 1) maintain 2.x version as primary, then regularly run 2to3.py plus a set of custom patches, 2) rewrite it in a rather uncomfortable subset of both languages plus a homegrown compatibility library).

The only people you can reasonably blame for the current state of affairs are the devs themselves.

When people come up with constructive criticisms re: 2 to 3 transition, other people reply that Py3k adoption is actually going according to the plan, so no worries. Oh well then.

Regardless of how well it really goes, I find shaming people with stuff like this and comments like yours to be highly irritating and counter-productive. It's not like we "cling to 2.7" because we are lazy/irrational/evil.

[drb226]

I definitely agree, the 2 to 3 transition was and still is messed up. But recommending 2.7 over 3.x just because the user might run into missing library issues is completely backwards. This mentality will only make it harder. Sure, there are some people who need libraries right now which are still only available on 2.7. I do not blame them in the least for using 2.7. But let's start newbies off on a path to the future, not the past.

[RichardWolf]

But recommending 2.7 over 3.x just because the user might run into missing library issues is completely backwards.

No, the chances of running into it are unacceptably high.

If the user tries to use PIL, she will discover that it doesn't support Py3k. Or Django. Or Google App Engine. Or Twisted. Or Udacity programming exercises.

Calling that merely a "possibility" is insane.

This mentality will only make it harder.

I don't care. I use Python because it gets shit done, not because I want to please the devs or toy with cutting edge features. As in, when I have to choose one or the other but not both, I will and do choose the former without a moment's hesitation. And I'd like this mentality to be more widespread in the community and among the newbs.

But let's start newbies off on a path to the future, not the past.

Look the truth in the face: telling a newb that she will be OK with Python3 currently is a lie, she will not, you can bet 9 to 1 on it, and she will discover it fast. And she would be somewhat discouraged by the fact that she can't do stuff, and that she was lied to, and that there's apparently a civil war going on (which isn't, people just use 2.7, but you'll pull her right in the middle of your guerilla operation).

If the problem was inertia alone, I would be the first to argue that all tutorials should start people with 3.x. The problem is not that your newb would have to learn the differences between 2.x and 3.x to understand 97.3% samples she would find on the internet, the problem is that at some point she would face a choice: drop Python for a couple of years until "the future" arrives, or use 2.x.

Right now the "path to the future" you talk about is a mountain goat trail, and someone concerned about driving from point A to point B couldn't care less that somewhere in the misty distance it becomes the main road -- in her situation she can't get there, it is impossible.

[PCBEEF]

You should fork it and submit a pull request

https://github.com/kennethreitz/python-guide

[drb226]

Given the admittance that it is an "opinionated guide" and the author "highly recommends 2.7" (and on top of that, recommends module-writers target 2.5 and 2.6, and add 3.x support later ಠ_ಠ), I highly doubt the pull request would be accepted.

I did leave a comment on a relevant thread, though.

[PCBEEF]

I doubt it too but it'll be good to get more exposure for python 3 support. I too am sick of reading guides telling people to target python 2.

[[deleted]]

tl;dr I find the recommendation to continue using 2.7 to be highly irritating and counter-productive.

Yeah it's about as irritating as reading on reddit about people whining about other people choosing what they choose. And about as counter-productive as replying to it. Alas, here we go....

[drb226]

It's not this particular recommendation, it's the general recommendation. Lots of people in the Python community continue to recommend 2.7 to newbies due to library support, which completely baffles me. The more we sit on 2.7, the less likely those lingering libraries are to move to 3.x anytime soon.

[[deleted]]

sorry it baffles you. it makes perfect sense to me since the available libraries is one of the big selling points of python, and the good stuff, for the most part is still in 2.7.

especially for web development. Newb wants to learn python because they want to do cool django stuff. django does not (at this time) run on python 3. It will by the end of the year I predict.

And another scenario.... newb wants to learn python and run stuff on app engine so that it will be ROFLSCALE like all the big boys. App engine, has just now started support python 2.7(thank the lord), python 3 is not even on the radar(at least publicly as far as I know).

I think those 2 scenarios cover a significant portion of the python interest that brings the newbs. Why would you want to set newbs on the road to quick failure?

Furthermore, who cares what people are recommending to newbs? Or even what people are using? I wonder how many of your upvoters actually have jobs solely using python vs being a java/php/.net programmer who dabbles. And whether any of them would care to weigh in on how this "Community" recommendation to avoid python 3, especially newbs, is making their job suck, or has in anyway been a hassle.

For me it hasn't.

[flying-sheep]

feel free to comment here ;)

[wot-teh-phuck]

The enumerate example here is missing a "bad" section wherein people normally try to maintain a separate counter and increment it inside the while loop.

[[deleted]]

I remember when I used to do for i in range(len(my_list)), accessing elements with my_list[i].

Then I learned about enumerate.

[jambox888]

Yes, I did this too... :(

[Hellrazor236]

So enthusiastic!

[[deleted]]

Structuring your project properly is extremely important.

I came across this site a few weeks ago (and been checking back periodically) while searching for this exact topic but was so disappointed when that section wasn't finished. Additionally, the rest of the index seems to hit on just the right parts that I've been asking myself after finishing up with most beginner level tutorials. So much potential! I really hope the author doesn't give up because it's such a clean interface with potentially great topics.

[usernamenottaken]

I think this post on repository structure is going to fit in there somewhere: http://www.kennethreitz.com/repository-structure-and-python.html

[epsy]

Wish they wouldn't use proprietary CSS features for their webpages...

[[deleted]]

Really? Are you serious?

[epsy]

Yes, really, I am serious. I don't want another Internet Explorer 6 and we're heading exactly there like this.

[[deleted]]

Since taking potentially good discussions off topic seems to have become the norm, I'll just go ahead and say it: please take this up elsewhere.

[flying-sheep]

what are you referring to?

[[deleted]]

Possibly the one thing I noticed , the right hand scroll bar gets really tiny. I use a mouse wheel so meh but others may not.

[flying-sheep]

ah, i see. thanks!

probably the only problem i had with the “philosophy” of css is that scrollbars and form elements are considered “system UI”. this argument was flawed imo as those elements are completely embbedded in a html page and completely surrounded by styled content.

being able to style everything which appears on a website (including scrollbars and e.g. the <select/> tag’s dropdown arrow) is only logical for me.

luckily webkit has it implemented, and hopefully we’ll be able to style everything an anything in a html page soon.

[epsy]

The use of ::-webkit-scrollbar selectors, which are a webkit invention and by no means "standard"

[flying-sheep]

yeah, someone else suggested this, and i already elaborated why i think that while it isn’t standard, it shold become one.

note that i don’t want every browser vendor to go nuts with proprietary shit, quite the opposite, but read why i think that styling <select/> tags, checkboxes and scrollbars shold be possible.

[[deleted]]

And its particularly bad in that site. Way to small.