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

141–150 of 355 posts

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

#141

Post by teh_klev »

bobbylarrybobby wrote: post #99
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 and Java can do that because they were designed reasonably well from the start. All they tend to add are more features on top of the solid core language. Python's language was not solid (e.g., strings not unicode by default) so they needed a major overhaul.

> JS and Java can do that because they were designed reasonably well from the start.

Javascript was knocked up over a week or so. Sure it implements concepts from Scheme and other languages but it was certainly not "designed reasonably well from the start". Otherwise we wouldn't have needed books such as Crockford's "Javascript The Good Parts" to help us understand areas of the language to avoid/misuse.

> Python's language was not solid (e.g., strings not unicode by default)

From the article:

"Python itself predates the first volume of the Unicode standard which came out in October 1991."

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

#143

Post by downerending »

joshuamorton wrote: post #92
carapace wrote: post #54

Earlier quoted context omitted.

I actually find this aspect of the whole thing exciting, perhaps paradoxically. Now that Python 2 is static the runtime can become asymptotically bug-free. Meaning that, if you only change it to fix bugs (as opposed to introducing new syntax|semantics) it's going to approach perfection.

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.

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

#144

Post by AnimalMuppet »

dragonwriter wrote: post #41
chungy wrote: post #20

Earlier quoted context omitted.

Can you describe how OOP feels tacked on? One of the major changes in Python 3 is that new-style classes are the only style of classes.

I think for some people having the receiver as an explicit parameter of methods rather than references through a special syntactic variable bothers some people and makes it look to them like a procedural language playing OO, though I personally think it's the most clear representation of what every class-based OO language actually does operationally, since methods are attached to a class and take a reference to the i…

It may in fact be what every class-based OO language actually does operationally. But having the OO language do that for you is, to me, one of the lines that separates them from "a procedural language playing OO".

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

#145

Post by acqq »

jnxx wrote: post #133
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...

> 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... Common Lisp has a backwards compatibility which goes into decades, and implementations like SBCL had no difficulties at all to absorb Unicode. Racket even supports different language standards and completely different languages (such as Scheme and Algol) running on the s…

> But the incompatibility between Python 2 and Python 3 is perhap s only a symptom of a larger problem. The Python developers have decided that backwards compatibility is not that important any more.

Exactly: and that was a wrong decision for anybody but the developers of Python.

Everybody else prefers having something that works: "The improvements are welcome, but please allow us to to run our old programs too, thank you, and allow us to use that new feature only once we need it."

It's an obvious expectation. We would also hate a new version of a word processor which wouldn't open our old documents. Or a new version of Photoshop which wouldn't open our old pictures. Or a new version of the browser where only the newest web pages are visible.

It follows that it was absolutely technically possible to have a new version of Python in which the old programs still work. It's the failure of the developers that they haven't made it.

Compare that decision of theirs with the policy of Linus Torvalds who insists that the old user programs should never break on newer kernels.

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

#147

Post by daveguy »

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…

> 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.

Only if they name it something completely different from python or py-anything. Guido refuses to allow anyone to just step in to maintain py2.

Tauthon is a project that aims to keep compatability with py2 while adding whatever features of py3 that won't break py2 and to have a maintained py2.

https://github.com/naftaliharris/tauthon

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

#149

Post by marcus_holmes »

crustacean wrote: post #35
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 such a good point. Take SQL. It has survived because it is well designed, and changes so little and so slowly, and it’s obvious what SQL is and isn’t meant for. Amateur programmers can port SQL queries between database systems semi-painlessly. In the right environment a query can survive with small edits for YEARS. Who wants to break old SQL? Nobody.

> Who wants to break old SQL? Nobody.

Every couple of months there's a new startup / dev site that says "SQL is broken/old/bad, so we reinvented it!". They all sink without trace, but there's a cohort who agrees with them.

Post reply on HN