Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Why Is the Migration to Python 3 Taking So Long?

stackoverflow.blog

Post reply on HN
Print view View original

181–190 of 355 posts

Re: Why Is the Migration to Python 3 Taking So Long?

#181

Post by downerending »

ogre_codes wrote: post #164
avisser wrote: post #161

Earlier quoted context omitted.

Now do C#. You are moving the goalposts and ignoring the fact that Python3 still didn't deliver anything for most users.

This is a hugely American point of view. For anyone who has to deal with unicode on a regular basis, the better unicode support alone is a huge improvement. That's without even looking at the advantages of Async support which offers big performance benefits for web developers—roughly 70% of Python users.

Note that the question is not "Shall we support Unicode?". Clearly we should.

The question is rather whether it would have been better to gradually improve support for it in a Python2-esque way, rather than creating a discontinuity and a raft of new problems, some of which linger to this day.

Also, for many purposes, there is wide agreement that ASCII is still the way to go. Even if Americans vanished tomorrow, the majority of remaining programmers in the world would prefer to look at source code in English, which they already know, rather than a host of other languages, most of which they don't.

Re: Why Is the Migration to Python 3 Taking So Long?

#182

Post by pmontra »

takeda wrote: post #160
recursivecaveat wrote: post #81

The simple reason is that there was no compelling feature to reward you for upgrading. You'd spend a tremendous amount of effort for dubious return and (until recently) a smaller ecosystem. 1. Unicode support was actually an anti-feature for most existing code. If you're writing a simple script you prefer 'garbage-in, garbage-out' unicode rather than scattering casts everywhere to watch it randomly explode when an in…

> Unicode support was actually an anti-feature for most existing code. If you're writing a simple script you prefer 'garbage-in, garbage-out' unicode rather than scattering casts everywhere to watch it randomly explode when an invalid byte sneaks in. If you did have a big user-facing application that cared about unicode, then the conversion was incredibly painful for you because you were a real user of the old style.…

> In python 3 it always blows up when you mix bytes with text so you can catch the issue early on.

This is definitely the case. I've been wrestling with bytes and strings all the time during the port of a Django application to Python 3 for a costumer. I can see myself encoding and decoding response bodies and JSON for the time being. For reasons I didn't investigate I don't have to do that with projects in Ruby and Elixir. It seems everything is a string there and yet they work.

Re: Why Is the Migration to Python 3 Taking So Long?

#183

Post by some_random »

takeda wrote: post #160
recursivecaveat wrote: post #81

The simple reason is that there was no compelling feature to reward you for upgrading. You'd spend a tremendous amount of effort for dubious return and (until recently) a smaller ecosystem. 1. Unicode support was actually an anti-feature for most existing code. If you're writing a simple script you prefer 'garbage-in, garbage-out' unicode rather than scattering casts everywhere to watch it randomly explode when an in…

> Unicode support was actually an anti-feature for most existing code. If you're writing a simple script you prefer 'garbage-in, garbage-out' unicode rather than scattering casts everywhere to watch it randomly explode when an invalid byte sneaks in. If you did have a big user-facing application that cared about unicode, then the conversion was incredibly painful for you because you were a real user of the old style.…

>Actually that's the behavior of python 2, it works fine, until you send invalid characters then it blows up.

We're talking about simple scripts, the solution is to not send in invalid characters.

Re: Why Is the Migration to Python 3 Taking So Long?

#184

Post by coldtea »

btreecat wrote: post #112
coldtea wrote: post #69

Earlier quoted context omitted.

> This is backwards thinking. And the alternative is cargo cult "newer is better". > Yes, it's expensive to upgrade from Python 2 to Python 3, but it's also expensive for the Python project to maintain 2 versions of Python indefinitely. On the other hand, they could progressively enhance upon a backwards compatible single 2 version. JS manages to do that just fine, as does Java...

>JS manages to do that just fine How do you define just fine? It's taken us many years to migrate EMCA versions only to have multiple incompatible runtimes. And JS "The good parts" is like 1/10 of the full language so often it feels like a lot of pile on. >as does Java How are them generics?

>How do you define just fine?

Besides the total domination of the web programming space, which is of course aided by it being the only option:

1) Used by choice even on the server and application development (where it was never the only option, and wasn't even preferable/viable before)

2) Fast pace of language development

3) A thriving package ecosystem with millions of packages

4) Adopted by all major companies

5) Three best of class runtimes (v8, JavascriptCore, Tracemonkey (?)) by 3 major vendors, with performance that smokes any dynamic language that is not LuaJit

6) Increasingly adopted as an embedded scripting language in all kind of apps

7) With a viable gateway into both a native trans-language runtime (webassembly) and a typed version of the language (typescript).

>How are them generics?

They're doing great. It's not that type erasure is that big of a deal, and Java might even get it with Valhalla eventually anyway. It's not a "backwards compatibility prevents this" issue (which is our topic here), it's a "no time devoted to add it in yet" issue.

Re: Why Is the Migration to Python 3 Taking So Long?

#185

Post by ageofwant »

jordigh wrote: post #177
ageofwant wrote: post #171

Earlier quoted context omitted.

Again with the 'Tremendous amount of effort' meme. I've done many ports and they were all trivial: - run 2to3 - spend 2h max fixing any failing tests - cook of any remaining issues in a few days of beta testing like you'd do for any new release Now now doubt Python 2.7 is a excellent and solid release and will remain so for as long anyone keeps the bitrot in check, but to keep using it because porting is 'hard' is pa…

Behold the tremendous amount of effort for Mercurial: https://www.mercurial-scm.org/repo/hg/log?rev=py3&revcount=2... They've been porting hg into Python 3 for the last 10 years and are only now nearing completion. I've written a bit more about this in Lobsters: https://lobste.rs/s/3vkmm8/why_i_can_t_remove_python_2_from_...

Yes of course there will be exceptions. But the vast majority off Python code bases are not mercurial or dropbox or imgur. Just like the vast majority of software using companies are not google or facebook.

The average few hundred to few thousand loc app, which should be 98% of all production code-bases will almost certainly port with no issue.

Re: Why Is the Migration to Python 3 Taking So Long?

#186

Post by coldtea »

ogre_codes wrote: post #163
coldtea wrote: post #69

Earlier quoted context omitted.

> This is backwards thinking. And the alternative is cargo cult "newer is better". > Yes, it's expensive to upgrade from Python 2 to Python 3, but it's also expensive for the Python project to maintain 2 versions of Python indefinitely. On the other hand, they could progressively enhance upon a backwards compatible single 2 version. JS manages to do that just fine, as does Java...

> And the alternative is cargo cult "newer is better". Of course it's a "cargo cult" when someone disagrees with you. > On the other hand, they could progressively enhance upon a backwards compatible single 2 version. JS manages to do that just fine, as does Java... "Just fine"... that explains why so many shops are dropping support for straight Javascript and switching to TypeScript or CoffeeScript before that. And…

>Of course it's a "cargo cult" when someone disagrees with you.

No, it's obviously "backwards thinking", right?

>* "Just fine"... that explains why so many shops are dropping support for straight Javascript and switching to TypeScript or CoffeeScript before that.*

CoffeeScript was just adopted (and not that much in the first place) because it brought new syntax/features earlier. Now JS has been getting new syntax itself at a great pace and CoffeeScript just died off.

As for TypeScript, this is just Javascript + type annotations. Kinda like what Python is getting with 3.6 and mypy, but more useful and with actual tooling available. So not sure how "TypeScript or CoffeeScript" prove anything about JS not doing great.

>Likewise, Java development is slowly being superseded by Kotlin. Java is a mess, there are often 3-4 ways to do simple things and many of them are just terrible for performance.

Python has 10x+ worse performance, and more than 3-4 ways to do simple things (from package management to basic libs), most of which are just terrible for performance.

Compared to that, nobody has had any problem with Java performance for 15+ years...

And Kotlin is still insignificant except in the Android space where it's pushed, so there's that. Java sees an order of magnitude more usage.

Re: Why Is the Migration to Python 3 Taking So Long?

#187

Post by flukus »

ogre_codes wrote: post #59
semiotagonal wrote: post #13

Earlier quoted context omitted.

I wonder how many people feel that migrating to Python3 would have been worth doing in the absence of being forced to do so. Dropbox invested three years of work, actually hired Python's creator, and are still not done. What are they getting out of it that they wouldn't have gotten if Python2 simply had been maintained?

This is backwards thinking. Yes, it's expensive to upgrade from Python 2 to Python 3, but it's also expensive for the Python project to maintain 2 versions of Python indefinitely. If someone wanted other than the core Python team wants to step up and maintain Python 2, they are free to do so, it's open source. But failing that, expecting the Python team to support the older/ less functional version of the code indefi…

> Yes, it's expensive to upgrade from Python 2 to Python 3, but it's also expensive for the Python project to maintain 2 versions of Python indefinitely.

No maintaining 2 versions of python is much cheaper, it's only being done in one place compared to the thousands and thousands of python 2 code bases you'd have to convert.

It also only needs bug fixes, there are plenty of people/organisations out there that would be perfectly happy for the language to be unchanging.

Re: Why Is the Migration to Python 3 Taking So Long?

#188

Post by jlokier »

d0mine wrote: post #154
dividuum wrote: post #62

Earlier quoted context omitted.

> The only real killer feature of Python3 is the async programming model. I understand that this is one of the major features, but I personally never saw the appeal, given that gevent exists and in my experience works well most of the time. It also allows me to multiplex IO operations and doesn't rely on new syntax. I'm probably missing something?

In gevent, any call may behave like an implicit "goto". Here's why "goto" is bad https://vorpus.org/blog/notes-on-structured-concurrency-or-g... (the link is stolen from @hermod's comment above)

I think the nursery construct described in that link looks a lot like par blocks in Occam, Handel-C and XMOS XC.

Re: Why Is the Migration to Python 3 Taking So Long?

#189

Post by coldtea »

kick wrote: post #128
coldtea wrote: post #69

Earlier quoted context omitted.

> This is backwards thinking. And the alternative is cargo cult "newer is better". > Yes, it's expensive to upgrade from Python 2 to Python 3, but it's also expensive for the Python project to maintain 2 versions of Python indefinitely. On the other hand, they could progressively enhance upon a backwards compatible single 2 version. JS manages to do that just fine, as does Java...

Almost everyone hates both Java and Javascript.

Javascript is a hugely popular language, as is Java.

Some hipsters hate "Java and Javascript". The world at large loves them.

At some point plain users hated Java applets and Java desktop apps, but those are not a thing much more. In the server space, very few that use it hate Java, and millions use it.

Re: Why Is the Migration to Python 3 Taking So Long?

#190

Post by arbie »

downerending wrote: post #143
joshuamorton wrote: post #92

Earlier quoted context omitted.

Who will do that though?

I've considered taking it on. If there were enough money in it, I'd very seriously consider it. It's a very good language.

In ten years, there will be serious money in it as enterprise codebases need to be renewed.
Post reply on HN