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Comment by nelmaven | Hacker News Reader

This sort of war between Python 2 and Python 3 is why I never looked seriously into Python. I don't know where should I start.

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It's the same language. This is not the break between Perl 5 and 6 which was different languages only keeping the brand.

I find it very easy to write code which is simultaneously Python 2 and 3. A few ``from __future__ import`` statements and you'll be fine. The only reason some people are complaining is that they were ignoring bugs in their code regarding text data. It's not a Python problem, it's a problem with computers -- bytes are not text, but many systems ignore the difference.

Many large enterprises are starting new projects in Python 3 exclusively. It's fine if you want to use some Python 3-only syntax.

> It's the same language.

No it's not. The syntax is what defines the language:

      In linguistics, syntax is the set of rules,
    principles, and processes that govern the structure
    of sentences in a given language.

It doesn't have the same syntax. It's not the same language, by definition.

Then why do we have two different words -- syntax and language? Python is a high level language, a bytecode, a standard library, and an interpreter (or many interpreters). You might also lump into that a culture, a community, and a Zen.

When we say it's the same language, most of those aspects are the same from Python 2 to Python 3.

With such definition python 2.5 and python 2.6 are different languages, because they have different syntax (python 2.5 does not support "with" statement).

Do you consider this definition to be nothing but absurd? I think it has a lot of merit.

What impact does one or other way of thinking (absurd vs has merit) about this (a potential break in backward compatibility between language versions due to any addition, removal or alteration of one or more language features) have on the language and its ecosystem and culture?

Imo:

* such potential breakage is relatively benign iff there's an easy-to-follow technique (eg using a linting tool or a program editor's search feature) that always ignores/accepts code compatible with the older language version and always catches/rejects code compatible with the newer language version.

* a further improvement on this is to have the inter-version checking done by a language's interpreters/compilers.

* best of all is when the language is at least partly compiled and compilation using the older interpreter/compiler does the rejecting at compile-time.

Samantics

Honestly that was a big part of it for me, too and when node.js and io.js originally split I was worried for something far worse for the JavaScriot community. Fortunately node got its shit together (for the most part) but every time I try to use Python 3 for a project someone else tells me I can't because X, Y and Z so I have yet to use any Python 3. Kinda makes me sad in a way because it has lots of things I want to take advantage of.

But I do feel like tides are shifting and Python 3 is slowly "winning". It's just taking, what, almost a decade longer than most would have hoped?

Python 3.5, installed by default on LTS distributions, and available everywhere else.

Output from my systems right now:

"Ubuntu 15.10" - Python 2.7.10

"Ubuntu 14.04.4 LTS" - Python 2.7.6

Not sure where you're getting the "by default 3.5" from.

    ＞ python3 --version

Or: http://packages.ubuntu.com/xenial/python3

the python executable will probably be python 2 for quite some time to come. type python3 --version

Python 3.6

No, still in alpha. If you're just tinkering, sure.

Same here with me. But seeing how nothing is being done in perl anymore, I am forcing myself to at least start using python3. I don't see any point in learning ruby, and all the other new languages out there are sorta still niche. There is plenty going on though with python and django (at least jobwise)

But yes, the "now there are two ways to do it" brought on by 2 and 3 really sux.

I should also say I always hated the "small" syntax changes even between the point releases. This was also something that kept me away (ruby has this problem too). Perl never had this problem, stuff written in 2001 can still run on perl of 2016. But I see now that this is a double edge sword. I have worked for several companies that run modern perl versions but refuse to touch their code base that was written like it was 1998 because it just "still works". That was another reason I started looking into python. I very much welcome complete breakage every few years at this point. It will at least force people into staying modern with the stack they use instead of becoming a 15 year old fossil with a disgusting resume. (I mean, what would you do if someone sent a resume to your dev shop that said they have only done CGI perl for the last 15 years and have no idea what javascript is or why they should learn it?)

Start with Python 3, the differences isn't something that you can't pick up in an hour, and since you won't have existing python 2 code base you probably will never need to do that.

The biggest issue people are having is to convert their python 2 code to work on python 3. There's virtually no downside to use python 3. All maintained libraries work with python 3.

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