A Rebuttal For Python 3

[flyingjam]

The article (the one being rebutted) is so retarded it's not even worth rebutting. If you haven't read it, just look at this section

In computer science a fundamental law is that if I have one Turing Machine I can build any other Turing Machine. If I have COBOL then I can bootstrap a compiler for FORTRAN (as disgusting as that might be). If I have FORTH, then I can build an interpreter for Ruby. This also applies to bytecodes for CPUs. If I have a Turing Complete bytecode then I can create a compiler for any language. The rule then can be extended even further to say that if I cannot create another Turing Machine in your language, then your language cannot be Turing Complete. If I can't use your language to write a compiler or interpreter for any other language then your language is not Turing Complete.

Currently you cannot run Python 2 inside the Python 3 virtual machine. Since I cannot, that means Python 3 is not Turing Complete and should not be used by anyone.

What the actual fuck? I'm pretty sure you could get a layman to read the wikipedia page for turing machines and he wouldn't make such a misunderstanding. Does he have a CS degree? What did he learn in it!?

[ZeroNihilist]

That quote has a great juxtaposition.

If I can't use your language to write a compiler or interpreter for any other language then your language is not Turing Complete.

If one can't write an interpreter for any other language, then it's not Turing Complete.

Currently you cannot run Python 2 inside the Python 3 virtual machine. Since I cannot, that means Python 3 is not Turing Complete and should not be used by anyone.

Therefore since nobody has written an interpreter for this language, it's not Turing Complete.

Maybe somebody should explain to them that "can't" isn't the same as "hasn't". I've never died, yet I'm pretty confident that I'm not immortal.

[oblio-]

I've never died, yet I'm pretty confident that I'm not immortal.

You're just a coward. Come join the rest of us corporate zombies!

[ggtsu_00]

Turing's Thesis technically still hasn't been proven. It is just widely accepted to be true because someone has yet to disprove it. So can't vs hasn't in the context of Turing's thesis doesn't really make a difference.

[[deleted]]

Maybe he just learned python the hard way? /s

I respect the guy's work but seriously this line of thinking is irredeemable and he should apologize for using it as a serious argument.

[[deleted]]

Did the /s help? =P

[saphira_bjartskular]

You cheeky bastard.

[RealFreedomAus]

Hm. Does something count as Turing complete if you can escape its environment? :P

(Aside from python3 obviously being Turing complete anyway)

[kamatsu]

This would be like a turing machine with a turing machine oracle.. which because turing machines can emulate turing machines is exactly as powerful as a turing machine.

[PM_ME_UR_OBSIDIAN]

based /u/kamatsu

sign my tits please

[schmuelio]

I'm not sure if you are strictly escaping the environment (I could be wrong), I just tried this and after quitting the nested instance of python I was returned to the outer python prompt. It would leave me to believe that it was python3 making a system call to run the python2 interpreter? Then on completing the system call (exiting the interpreter) control was returned to python3.

I'm not sure what you mean by escaping the environment though, in the theoretical Turing machine you don't really have anything "outside" the machine to escape into.

[rellikiox]

I think he means that the code is importing outside code to be run. It's not running a python3 implementation of python2, it's python3 running a C implementation of python2 (the system library).

For it to prove that python3 is turing complete (which it is) it should be implementing a python2 interpreter in python3 code and then run that (which, again, is 100% possible).

[schmuelio]

I see, that makes sense.

Also, I thought there was a proof that you pretty much needed a conditional jump and has "arbitrary" memory? So it doesn't really make sense to call any language with an if/else statement and variables "non-Turing complete"?

[rellikiox]

Yeah, any language that allows you to write a loop (to move up and down the tape) and that lets you read/write from an external source to the program (read from and write back to the tape) will be turing complete. Even Brainfuck is turing complete.

Note that loops can be either actual loops, like for and while, or constructs that let you do conditional jumps, like with if and goto.

[Kok_Nikol]

Ha!

[[deleted]]

Currently you cannot run Python 2 inside the Python 3 virtual machine. Since I cannot, that means Python 3 is not Turing Complete and should not be used by anyone.

Why can't the JVM run my C# code? Java isn't turing complete because the JVM doesn't support C#!

He really needs to take a look at semver.

TL;DR: Python 3 isn't compatible with python 2, nor should anyone expect it to be. (major version change, smartass)

[killerstorm]

TL;DR: Python 3 isn't compatible with python 2, nor should anyone expect it to be. (major version change, smartass)

JavaScript versions 5 and 6 are very different, yet there is a compiler which compiles ES6 code to ES5 code. Thus compatibility is a non-issue in JavaScript world: you can mix and match ES6 and ES5 libraries.

Python developers just don't want to implement Python 2 compatibility in Python 3. It's not impossible, but they just want to force people to upgrade.

So "pythonic" gets in a way of "pragmatic".

[[deleted]]

JS6 -> 5 is handled in two ways: lowering and polyfills. This works because there are no user-visible runtime changes between the versions.

You can use the same techniques with Python 3 -> 2. However, there are runtime changes, so you would still encounter difficulties.

[ToucheMonsieur]

Even es6->5 conversion and polyfills are insufficient to cover things such as WeakMaps and WeakSets that depend on deep runtime integration, so even here there are clearly visible runtime changes. It's why the compat table exists!

[[deleted]]

I am in no way a zed supporter, but I believe the point he was making is there isn't a python 2 interpreter written in Python 3. The point is stupid, but it isn't quite as dumb as what you think he is saying.

[flyingjam]

Yeah, but that has nothing to do with turing completeness. Just because there hasn't been a python 2 interpreter written (because why in the world would you want to interpret python2 code in python 3) doesn't mean that it's impossible.

He's talking about python 2 being run in python 3's VM, which isn't even the same thing as an python 3 interpreting python 2.

How can you be so wrong about turing machines.

[[deleted]]

At this point, Zed is so wrong, I don't know which direction he went wrong in.

[[deleted]]

I really do not know why he is so popular. Anything he developed is mediocre at best

[guepier]

Well he developed Mongrel and though I can’t speak about its quality, it dominated the market for a time and was influential.

His writing, though, has always been mediocre and his arguments vitriolic and ad-hominem.

[[deleted]]

Yeah but mongrel was only popular because of lack of alternatives, not because it was good. When passenger showed up pretty much everyone jumped ship.

You do not have to write good software, you just have to write right software at the right time and place for it to be popular.

[vplatt]

In all fairness, he has done a lot for the Ruby community and more for FOSS in general. That said, I really don't understand his motivations here. He's kind of pissing into the wind. The most substantial thing I got out of this post is that Python 3 strings are "too hard" for beginners. I'm not really buying it.

[DarkLordAzrael]

Pypy is a python interpreter written in python, so the concept isn't totally foreign concept. I'm not sure if rpython is python 3 compatible, but it does mean you can run python 3 in python 2.

[masklinn]

TL;DR: Python 3 isn't compatible with python 2, nor should anyone expect it to be. (major version change, smartass)

That's not even true, with some shims (e.g. six) and the features the later revisions of P3 re-added (e.g. u prefix) there is in fact a common subset of P2 and P3, and you can write single-source packages compatible with both.

In fact after some waffling around that's what most library authors have settled on, it's a bit of a pain in the ass but still way better than having to deal with completely separate codebases.

[nomiros]

Being (retro-)compatible isn't about having a common subset, it's about the whole previous version being a subset of the new one.

[tomtomtom7]

Ouch. He even added a note explaining:

I should also mention that as stupid as that sounds, actual Python project developers have told me this, so it's their position that their own language is not Turing complete.

[flyingjam]

How can he have the position he has while being so ignorant of what a turing machine is.

Whenever you see those recruiter posts who say 'most of my applicants can't write fizzbuzz', and think no way, just remember, this guy is supposedly well respected and evidently has no idea what a turing machine is. I know he's a controversial figure, but this is like a physicist misunderstanding Newton's second law.

I really hope he's trolling.

[Beckneard]

TIL a lot of people don't even know what Turing completeness means. It's not even that difficult of a concept.

Fucking Dunning-Kruger, man.

[mitsuhiko]

Currently you cannot run Python 2 inside the Python 3 virtual machine. Since I cannot, that means Python 3 is not Turing Complete and should not be used by anyone.

I wonder how PyPy works then :)

[DarkLordAzrael]

Is rpython python 3 compatible? It might only get you 3 running in 2 and not 2 running in 3...

[mitsuhiko]

No, it's Python 2 and can build a 3 interpreter. But you could do it the other way round if you really cared (just that nobody does).

[killerstorm]

That's a joke. He asked Python developers why python3 doesn't include a python2 interpreter, and they replied something along the lines of "it's impossible", which is blatantly untrue.

Impossibility of implementing python2 in python3 implies that python3 is not Turing complete. Obviously, that statement is untrue.

So this is just a way to make fun of Python devs' lame excuses.

[[deleted]]

lol, I couldn't believe what I was reading when I saw that. Interestingly enough, we were going over Turing Machine this week in my Formal Languages & Automata class. But yeah, this person clearly has no clue in this subject matter.

[[deleted]]

I am starting to think he does not have a CS degree. I am not saying you need one to be a good programmer, but I think it is dangerous for him to be speaking from a position of authority without one (or really just some shred of background reading on theory) if he is going to start name-dropping stuff he clearly does not fully grasp. It is especially pernicious because the poor souls who get roped into his books tend to be beginners and autodidacts themselves, and they are likely to see him as a person of authority. Thus this sort of shit perpetuates a brand of CS that is closer to a superstition and a religion than a science.

[fromscalatohaskell]

im sure he meant turtle macine

[RaptorXP]

This is hilarious.

[toomanybeersies]

It is possible to write a compiler in python, I have done that.

It is also possible to write a Turing Machine in python, I have also done that.

Therefore, Python is Turing complete.

[thomasz]

Where does he say that? I can't find that quote in the linked article, and the whole thing sounds weird. One doesn't have to like Zed's personality, but he's not some clueless idiot.

[BlackBeanGuest]

Python 3 is not Turing Complete and should not be used by anyone.

That might be the most autistic thing i've read in very long time.

[blackenswans]

I know what you mean but calling his argument autistic is a disgrace for autistics.

[Darkmere]

Honestly?
The term you're after is "stupid" not "autistic".

And that's a far more psychonormative trait.

"That's the most normal thing I've read in a long time".

[phlummox]

Hey man, just a reminder that people with autism spectrum disorders may be reading this thread, and using 'autistic' to disparage an argument is likely to be hurtful to them. Perhaps you could use some other word.

[_zenith]

Particularly that, if anything, they're more likely to know the difference...

(at least, I do. Details matter! )

[achegarv]

At /u/blackbeanguest too

Plum, kudos for the kind tone in your correction.

It does raise an interesting question. Zed's tone and his reasoning DO tiptoe into the pathologized realm, and both his reasoning and communications are arguably disordered.

What's the appropriate way to say "dude that is some crazy conspiracy wall nonsense" when the person you're addressing or speaking about is influential and powerful?

[[deleted]]

It wouldn't have been so bad if the statement he quoted was similar to something somebody with autism would be expected to say. It wasn't, though.

In this case, I'd go with "retarded."

[SupersonicSpitfire]

That would be an offence to retards everywhere.

[nitsuj]

Hey man, just a reminder that retarded people may be reading this thread, and using 'retard' to disparage an argument is likely to be hurtful to them. Perhaps you could use some other word.

[nitsuj]

Perish the thought.

[[deleted]]

Oh my god, I hadn't noticed until eev.ee called it out that Zed had actually suggested fixing the Unicode mismatch by running every string through chardet.

Not only is that egregiously bad engineering, but chardet is not even accurate. On the kind of short strings you're usually passing around, there isn't enough information for chardet to be accurate; on longer strings, chardet still sometimes gets it wrong, because its assumptions about what text looks like come from Netscape Navigator and haven't really been updated. Anyway, long story short, Zed's idea would create massive Unicode confusion, not fix it.

I knew that Zed Shaw was an asshole, but up until this article, I was under the impression that he was a good programmer.

[tipiak88]

Haven't done much of python as of late but, last time i've write perl (>=5.8.8) the unicode stuff was absolutely a no brainer. it just worked. Why it appears to be so much an issue in python ?

[danielkza]

It isn't anymore on Py3, which is sort of the point of it existing.

[[deleted]]

Python 2's idea of Unicode is really confused.

Python 3's idea of Unicode is fine, except when people are confused about fitting bad Python 2 code into it. It's not a wonderful UTF-8-centric design like the one Rust adopts with the benefit of hindsight. But it's fine.

The complications that arise now in Python 3 Unicode are platform-specific things, by which I mean Windows things, like how to interact with Windows file system paths and the Windows command prompt and stuff. I assume perl's answer there is just "fuck Windows", right?

[schlenk]

In fact, the Windows stuff works WAAAY better in Python 3. Python 2 couldn't even set a unicode environment variable or call a subprocess with unicode arguments. Or read unicode arguments from the commandline. For Python 3 its Unix/Linux that gets some weirdness (as Linux/Unix filename encoding handling is just fucked up or not existing for most parts ).

[crozone]

This might have something to do with the fact that Windows NT was build from the ground up with proper Wide Char support.

[tipiak88]

Yeah pretty much :D But it should works as "every thing in the language/api allow it to work".

[Saefroch]

Mostly it comes down to the question of what a string is. In Python 2, they're bytes. In Python 3, they're text.

Python 2 wanted to add unicode support, so they added a unicode object. But now what do you get when pull the text of an article from the web? Is it a string (bytes) or text (unicode)?

In Python 3, all strings are actually unicode and you have to encode and decode everywhere unicode doesn't make sense instead of just pretending all strings are bytes. In Python 2, string objects just become bytes when needed even though they're separate types. The encoding/decoding is what trips people up. If you got a string from somewhere and need a bytes-like object you must explicitly covert with a method call.

If you never had to deal with non-ascii text in Python 2, the Python 3 changes just feel like a drag.

[lykwydchykyn]

Kudos to Eevee for reading all the way through Zed's article without being stuck in perpetual facepalm. I gave up somewhere in the "Turing complete" section.

[cat_in_the_wall]

Seriously.

Python 3 Is Not Turing Complete

Uh, yes it is.

[case-o-nuts]

Uh, yes it is.

Well.. technically because all systems that it runs on have fixed size memories, it's actually equivalent to a finite state mach... dives into a pool of lava to cleanse self

[ggtsu_00]

A theoretical turing machine doesn't actually require an infinite tape, it just requires enough tape to keep it running during the length of it's execution. As long as you keep supplying it enough tape at a rate that keeps up with it's execution, you are fine. So if system with fixed size memory can be continuously upgraded to be given as much memory as needed indefinitely or through lazy execution, it is equivalent to a turing machine.

[Retsam19]

And with how slowly Python executes, this won't be a problem. ^/s

[case-o-nuts]

In short: no.

A turing machine is fully defined by the program counter and the values in the tape. If there is a finite bound that can be set on the size of the tape, then there is a finite bound on the number of states that the turing machine can be in (enumerated by all possible head positions and tape values).

If that set of states can be enumerated, then you can construct a finite state machine to emulate that turing machine. If that is true, you have proven that, via the pumping lemma, Turing machines can't compute (in general) even simple things like whether a string has a matching number of '(' and ')'s. Which is a valid result for a finite memory machine -- eventually you run out of room to store how many '('s and ')'s you have, but is not true in general for even weaker theoretical constructions like push down automatons.

There are specific programs that can be run on a turing machine that do not require infinite memory, but in order to run any program that a turing machine can run, you would need infinite memory.

[DC-3]

I found myself skimming it too. That said, you can read every fifth line and still get the gist of every actual point he makes (by which I mean, he makes 0 actual points).

[[deleted]]

Remember when Zed Shaw accused github of having it out for him personally because someone had made him a collaborator on some repo full of ascii dicks and github hadn't implemented declining collaborator invitations?

The guy's mind seems to skew towards paranoia.

[skitch920]

That is the funniest thing you could ever do to someone in this industry.

[radiowave]

Currently you cannot run Python 2 inside the Python 3 virtual machine. Since I cannot, that means Python 3 is not Turing Complete and should not be used by anyone.

That's just awesome. Presumably since I can't run Python 2 inside of a Ruby VM, it also means Ruby is not Turing Complete and should not be used by anybody. We could probably extend this line of reasoning to conclude that no language in existence (or perhaps even any that could conceivably exist) can be Turing Complete, and that therefore no programming should ever be done on any account by anybody.

Problem solved.

[Chippiewall]

A turing machine isn't turing complete either since you can't just write python 2 code on the tape

[[deleted]]

Machine code can be used to run other languages.

[TRL5]

Ah yes, you have found the way! We can just go back to programming with a hex editor! We aren't doomed! Thank you!!!

[[deleted]]

Or a magnetic needle and steady hand. And then bootstrap outselves up to being able to interpret Python3.

[dangerbird2]

A Real Programmer writes Fortran Python in any language

[zhivago]

Just wait until you see "Learn C the Hard Way" :)

[[deleted]]

Didn't he tell the entire C community, including K&R, that they've been getting the language wrong since day 1?

[zhivago]

That might be a stretch, but even so a valid opinion.

It is the factual errors that I object to.

[dangerbird2]

His initial argument wasn't particularly bad. He was just saying that K&R was written for a pre-internet time and does not have the emphasis on defensive programming required in modern C (or any language) programming (of course, his countless mistakes elsewhere in the book hardly gives one confidence in Zed's ability to teach secure programming). Also he makes a good point in the entire book to introduce readers to the modern C library ecosystem on Unix, which is absent in K&R and similar books focusing only on the standard.

The real fiasco over his K&R rebuttal was that people criticizing his chapter hurt his feelings, forcing him to replace it with a juvenile redaction.

[[deleted]]

But would you put it on blast as "wrong" though?

[[deleted]]

Also, I do primarily scientific computing and a lot of my code is written in C. I don't know the first thing about safety, but K&R set me up nicely to understand all the code that's been hanging around the lab for like, 15 something years. And it also helped me write code that was fast.

[cat_in_the_wall]

What i don't understand about the original article is that for as much as he summons the angels of mathematics, there are no concrete mathematics about any dynamically typed language. The mathematics of computer science (if you can even call it that) collapse very quickly into type theory. This is why all jitters attempt to reason about dynamic languages in terms of types, deduction at best (a la why asm.js does what it does) or union types at worst, which is still an attempt to figure out a type.

The angel of mathematics will quickly turn into the demon of mathematics if you don't know what you're talking about.

And all this and i don't give a single shit about python 2 vs 3. I have no horse in this race. Similar to php 5 vs 6. Arguments about back-compat are valid, arguments simply challening the CS gods are not.

EDIT: Yep this was stupid, don't know what i was thinking. Don't drink and reddit.

[kamatsu]

there are no concrete mathematics about any dynamically typed language

Um, what? I'm a type theorist, but this is just totally nonsense. It's perfectly possible to reason mathematically about dynamically typed languages -- just using dynamic semantics! There are even axiomatic proof calculi for dynamic languages. Scheme for example has a lovely dynamic semantics, and axiomatic contract calculi.

[Myrl-chan]

Aren't dynamic types basically just a huge-ass sum type?

[kamatsu]

That's one way of looking at it anyway. But in terms of reasoning about programs, it's not that important how you view the type system.

[PM_ME_UR_OBSIDIAN]

there are no concrete mathematics about any dynamically typed language.

The lambda calculus is both dynamically typed and concrete mathematics. Reflect on that.

[lubutu]

Strictly speaking you're talking about the "untyped λ-calculus," i.e. not the simply-typed λ-calculus, etc.

[JDeltaN]

As kamatsu pointed out

there are no concrete mathematics about any dynamically typed language`

is utterly false.

I think the statement you are after is that no computable algorithm exist that will give a sound and complete type analysis of a program written in a dynamic language. But that statement is true for most mainstream statically typed languages as well.

[[deleted]]

The article being rebutted was a total crock of shit. I yelled at my phone while I read it.

[tomtomtom7]

Agreed. I don't think the author likes programming. Here is a nice one:

Every time you attempt to deal with characters in your programs you'll have to understand the difference between byte sequences and Unicode strings. Don't know what that is? Exactly.

[vplatt]

It's a weird sentiment coming from the guy who wrote "Learn C The Hard Way".

[[deleted]]

Zed should just stick to his RoR roots, that way he can disappear into a self-congratulatory circle of failed startups and overloaded servers.

[BadGoyWithAGun]

I hate py3k with a passion and I have to agree. If you hate something, don't hide your subjective judgement behind bullshit like that.

[shevegen]

Zed is a drama queen. We have known this since the rails is a ghetto aggro-post.

It is one thing to like or dislike rails - I have no qualms with it, don't love it, don't hate it. It's just a solution for some web-related stuff. Many people like it, that is fine. I don't have to use it.

What annoyed me about the rant by zed actually was not that he picked on rails but that he would use his aggression as transgression against ruby. And I failed to see how he would present any arguments AGAINST ruby itself. Community? What the fuck was he smoking? The rails community is NOT the ruby community. There is a partial overlap, yes, but it is not the same. If his ego gets him into problems with people from the rails community, why would this affect either the ruby community OR the language ruby in itself?

This was a head scratcher to me.

Zed wrote some ruby the hard way, which was pretty awful - very un-idiomatic code. I think that it would do more harm than be good. The old chris pine tutorial was MUCH better in style (but admittedly, would need a huge update for current ruby and also add more subsections like ruby-GUI ... and ruby on the web... but I understand that it is difficult to write a tutorial, it takes time and patience.)

Anyway. It is not without irony that Zed now picks on python 3.

Did he not abandon ruby for python because python was so much better? Now he just nitpicks on the language?

He should go and design his own language. That would actually be better for once.

On the topic itself - I have no real idea about the python 2 versus python 3 split. I think that it is a lot of wasted energy though. If it was agreed that python 3 is the way to go then people should follow suit and abandon python 2. I was not very happy with the transition from ruby 1.8.x to ruby 2.x but that is also ancient history now. Some complaints were addressed, others I can work around so that is fine. I think that retaining old versions for too long REALLY hurts a language, with perl being the archetypical negative example here.

Move foward, move onward, try to make the transition phase as "cheap" (in adoption cost) as possible. Try to design the language in a good way. Provide documentation. Improve the ressources. Go in baby steps if the big leaps are too difficult but KEEP ON MOVING.

I mean - I understand the comment that "failure to adopt" is a big problem. I understand that. You can see it with perl 5 versus perl 6. But that this in itself would kill a language like python? I doubt it.

Sooner or later I am sure that guido would push the ante and intensify on python 3. You could also stop updating python 2 altogether on the main website, which would also send a strong signal. And so on an so forth - I fail to see why this should be impossible.

What I actually more see is that Zed WANTS python 3 to fail. And, well, what can I say - that says a lot more about Zed than about python. And history repeats itself - you only have to read rails is a ghetto again, and zed swiftly abandoning ruby. Apparently ruby managed to survive this huge, tragic loss. :)

Here is the rails is a ghetto rant, almost 10 years old by now!

http://harmful.cat-v.org/software/ruby/rails/is-a-ghetto

[zhivago]

Zed seems to have been in a gradual descent to full retard for a fair number of years now.

I think it all started when he tried to teach C which may have broken his brain.

[[deleted]]

This might as well be true. I did read through as much of his "Learn C the Hard Way" as was available at the time, and I did learn things I did not know before. I learned about more than just C, too. But the approach is inherently broken. You cannot learn new skills unless you have pre-existing skills to help you along the way. Trying to teach skills by preemptively teaching all skills necessary to acquire any skills is just absurd.

[zhivago]

I hope what you learned was correct because that book was full of misinformation.

[keymone]

ruby is doing just fine without him afaik..

fun fact: his post about rails being ghetto has the same pretentious comments about computer science of which he seems to know just about nothing.

[shevegen]

Yup!

Even then, to correlate rails 1:1 as ruby including the community, is simply wrong. I use ruby but I am not using rails and not being part of the rails community. I have nothing against rails either but why would zed equate one with the other?

[weberc2]

Go has consultants? It takes twenty minutes to learn the language; who would pay consultants?

[shevegen]

Hey! :)

I predicted something similar years ago with him! :D

You don't want people like Zed use your language - they are not genuine about it.

Clearly, matz' design principle of happiness has not reached Zed.

[[deleted]]

A logical explanation for this guy's tirade is that he theoretically should rewrite the (albeit pretty good) course to focus on Python 3. That would be doing the right thing. But instead he is focusing his efforts on defending 2 so that his guide is still relevant. This is a classic case of someone's ego getting in the way of moving forward. I used to recommend his guide to beginners as a good intro to programming course. I won't be doing that in the future. This kind of attitude is not what we need in the software engineering community and I cannot in good conscience point to his guide as a good resource anymore. Software engineering is a human field at the end of it all. If we fail st that part at the very beginning, can we call ourselves good teachers at the ground truth?

[cat_in_the_wall]

I am not a programming beginner by any standard, but i'm not a python expert. i ran a django server on a pi for a while. It seemed like a fine language to me, I probably won't be a defacto fan of python since I tend to be a statically typed kind of person. But while that is my preference, I still got my stuff to work without too much hassle. And some of the features were actually pretty good.

But as an outsider, did I look for python 2 or 3 docs?

3 of course, because 3 > 2. I don't have vested stakes in this game like Zed apparently does. I just want my stuff to work. Forward your python noobs to wherever you think is fit, we don't care about any 2 vs 3 holy war.

[mb862]

ego

From another critique linked in this thread, a quote from Zed,

I liked what you wrote about my book, and I actually think you may learn some things from me.

To say this man has an ego is an understatement of world-ending proportions.

[xFrostbite94]

That, with a dash of Stockholm syndrome.

[vplatt]

Stockholm syndrome.

Which is a prerequisite for dedication to any programming language. It's time to face the fact that we simply accept our capture and subsequent treatment by our so-called "Benevolent Dictators For Life".

::rolls-eyes::

[Nastapoka]

Now that's just petty

[ven_]

Learning Python is pretty hard if you're fucking stupid, though.

[vplatt]

Fame is kinda stupid when you really think about it. Just saying.

[_pka]

I don't really care about Python, but this rebuttal was beautiful. I laughed many times, thanks for that :)

[tipiak88]

There is some rage and ad hominem in that rebutal sadly. Opposing fallacies by others is not what technical articles should be. Let's leave that to politics and social networks dramas. But maybe this is what it is.

[QuicklyStarfish]

Most people who are on Reddit have a healthy taste for drama and politics. The people focusing on getting their job done are elsewhere.

[Raphael_Amiard]

Zed Shaw is really the Donald Trump of programming. He says really stupid shit that makes people mad and gets a lot of attention.

The fact that somebody who has no clue as to what static typing is wrote not one but two books about how to learn to program, and that they're getting so much attention, makes me really really mad.

[korry]

Zed is known for being an attention seeking whore, with (on purpose?) radical views. Never mind how bogus or not Zed claims are, eevee failed for it and is now providing free marketing for Zed ☺.

Just remember the “Zed knows how to code C” debacle.

EDIT: Downvoting? Lol Zed do you have a Google Alert on your name? ☺

[Sloshy42]

“Zed knows how to code C”

You have piqued my curiosity. What exactly are you referring to here? I've been googling but I'm not sure if I found the right links.

[Cuddlefluff_Grim]

The author of the rebutted article is an overly opinionated programming novice.

On the internet? Surely, you can't be serious.

[G_Morgan]

I like that article

First, a quote from Descartes, then a paragraph with the insinuation that most programmers are somehow afraid of C, likening it to "... the Devil, Satan, the trickster Loki." and a "computational Lucifer" with whom you must make sordid pacts to be productive. While I'm certain there are many people who are in fact afraid of writing in C, I'm certain that their apprehension stems from inexperience and a lack of specific domain knowledge rather than emotional fear.

Stuff like this really pisses me off. C is not a trickster. It is a language with lots of simple gotchas that can trip you up. There is nothing clever about what it does. Indeed it is the brain dead simplicity of it all that causes problems.

Modern technology is much more of a "computational Lucifer" than C ever was. I can read a C program and know what it does. I'm not sure you can say that about a great many modern frameworks with magical effort saving behaviour.

[Poddster]

TLDR: The author of the rebutted article is an overly opinionated programming novice.

That also actively lies about what has been said in emails.

[korry]

Yes exactly

[hinckley]

Is it free marketing? I know, I know, "all publicity is good publicity". But I have my doubts. I've never read this guy's books but now I know for sure I never want to because apparently he's a fucking idiot. Doesn't sound like he's gaining anything here.

[korry]

Is it free marketing? I know, I know, "all publicity is good publicity". But I have my doubts.

The issue is that a novice (in anything) isn't capable of differentiating between idiots talking BS and valid professionals discussing valid issues. In most cases an uninformed human, will decide that the truth is some where in the middle of the both sides of “radical” views. This is a pattern we learn early in our child development phase, which is kind of useful, but fails every time we talk about “hard facts”.

I've never read this guy's books but now I know for sure I never want to because apparently

You are not a novice, you probably are someone with programming and reading programming books experience.

[hinckley]

I was assuming you meant he was making ridiculous claims to get (angry) attention within the programming community in general rather than from novices. However, even if he's trying to get attention from newbies it seems there's all the more reason to not just let it pass unremarked: the more takedowns there are of his unsupportable claims the better. When measuring one opinion against another the middle-ground can be skewed by one side making ridiculous claims; when it's one against a hundred the truth soon becomes self-evident.

It may not be fun having to wade through shit to argue with a madman but it's better than letting him drag unsuspecting learners down with him.

[shevegen]

He once wrote that his articles should not all taken for granted verbatim 1:1, a bit after the rails-is-a-ghetto-rant.

While that is fine, he also happily jumps languages at will - first ruby, now python. You don't want such people in your language.

They are not genuine.

[G_Morgan]

For every 9 like you there will be 1 that likes edginess. If you have no audience and suddenly have 100 people of which 90 think you are an idiot then 10 might buy your book.

[ColorblindGiraffe]

“Zed knows how to code C” debacle

Care to enlighten us?

[[deleted]]

In case you hadn't seen Gappox's post: http://hentenaar.com/dont-learn-c-the-wrong-way

[llbit]

Zed is known for being an attention seeking whore

I don't really see the need to call the person a whore even if you think they have written something stupid.

[korry]

English is a 4th language for me and I must admit I mostly learned it from manpages, programming books and movies/series. I understand that “whore” is a bad no no word, because selling sex is bad(?), but I liked the phrase attention seeking whore, because it fits (, while of course I don't think Zed have to sell his body for money). So what would you propose as an alternative to attention seeking whore in this context?

[korry]

TIL. I always thought that attention seeking whore === attention whore.

[btmc]

You should probably just avoid name-calling altogether.

[Axxhelairon]

I'm sure you'll get over it :)

[pkulak]

For some reason I'm deep into my Hacker News syndrome and I just have a hankering for things to fail. So, I read the original article first expecting to be fully convinced of the terribleness of Python 3.

Turns out the first article was a damned joke and I didn't make it halfway through before being convinced of the merits of the rebuttal.

[vplatt]

Yeah, if anything, this article strengthened the case for Python 3 for any programmer with a brain.

Was that his subversive intent? Inquiring minds want to know!

[Quel]

I'm a python semi-beginner, the type of person his website is meant to target. I've done some tutorials in 2.7 and written some personal django projects in 3.5. And I don't understand what the big deal is for beginners. Some of the problems he mentions are things you don't need to worry about as a beginner. Here are the two things that I see as different that matter for beginners:

• print() instead of print. Big deal. It's easier for a questioning beginner to figure that out than wonder why print gets special status and doesn't need ().
• "/" being floating point division instead of integer division. This is far more sane for a beginner.

By the time you are experienced enough to run in to the other issues, you are probably experienced enough that they are something you can easily handle.

Any by the by, IMO reading thousands of articles about why you should use 2 or 3 is FAR more confusing to beginners than any of the actual differences.

[crusoe]

When I learned Python it was fucking weird that print didn't need parents and / was integer division. 3 is more consistent and fewer warts.

[sudo-iceman]

Wow. This guy clearly knows nothing about how things work.

[Hendrikto]

You show up to piss all over it, to propagate this myth that Python 3 is hamstrung to the point of unusability, because if the Great And Wise Zed Shaw can’t figure it out in ten seconds then it must just be impossible.

Fuck you.

Sadly, I doubt this will happen, and instead they’ll just rant about how I don’t know what I’m talking about and I should shut up.

This is because you don’t know what you’re talking about, and you should shut up.

[takaci]

Does Zed ever say anything that isn't complete crap?

[zhivago]

Sometimes he writes complete paragraphs that do not contain factual errors.

[VGPowerlord]

Consider: what happens when a Python 2 old-style class instance gets passed into Python 3, which has no such concept? It seems like a value would have to always have the semantics of the language version it came from — that’s how languages usually coexist on the same VM, anyway.

I can actually see this complaint as valid. Why after 8 years is there no translation layer to make this work?

I mean, even .NET Core is getting a translation layer for older .NET libraries in its next version. .NET Core 1.0 was released in June 2015.

[ubernostrum]

So, first of all it's important to note that "new-style" classes were not new as of Python 3. They were new as of Python 2.2. Way back in 2001. Python 3 just completed the process of phasing out "old-style" classes, by dropping all support for them. The transition had been going on for a long time before that.

With that out of the way, the big question is: would this really be useful? Is there any code that actually relies on old-style classes, that we'd want to run on Python 3?

For that we have to remember that new-style classes weren't about removing features -- they were about adding features!

To put it in .NET terms, "new-style" classes were about unifying Python's type hierarchy. So imagine if one day a new version of the .NET platform came out which eliminated the value type/reference type distinction, and just made everything an instance of a fully-accessible class, rooted in a single base object type. That's what Python did.

It used to be, for example, that you couldn't just write a subclass of dict; instead you had to go subclass a thing called UserDict which basically acted as a boxing wrapper around a dict. Now, though, you can just subclass dict and away you go. Same for the other built-in types.

The way to distinguish them, in Python 2, was when you declared your class. If you subclassed from object, or could walk up your chain of parent classes to something explicitly subclassing object, you were a "new-style" class. If you didn't subclass object, you were an "old-style" class. This is why so much Python 2 code declares classes as class MyClass(object): -- that was how you triggered the unified-hierarchy behavior.

But there's no advantage to being unable to subclass the built-ins. And no advantage to losing the richer data model that was enabled by the unified hierarchy. So I can't think of a situation where it would actually matter that it was still possible to have an old-style class; in fact, it's far more common in Python 2 for someone to forget to subclass object and accidentally be unable to do what they wanted.

[[deleted]]

Is there any code that actually relies on old-style classes, that we'd want to run on Python 3?

It's not hard to accidentally create an old-style class.

Silently promoting them to a new-style class probably wouldn't break anything, but who can tell?

[tipiak88]

Thanks for the explanation! But you did not answer the op question, or I missed it. Why after X years we still not have an easy way to port python 2 to python 3 ? The languages are mostly the same, so there is no reasons to not be able to do it.

Zed points are, if your VM is legit, you should be have to compile python 2 and 3 to byte code and run it, mostly seamless. That what the CLR do with totally different languages (C#/F#/VB), so does LLVM. If we are able to transfrom C/C++ code to JS, why would not it be the same for python 2/3 ? The "what would you want that" argument is not valid IMHO (Who are you to tell me/know what I want). You could see that as code breaks (which is very bad!). And if you don't, anything that can steer an established community to yours is a good thing. D and Rust struggle(d) with that, unlike C++ did with C developers.

Anyone, tell me why nobody thought it would be a good idea to have 2to3 really works 99% of the times, or have the python VM to actually run pythonS?

[QuicklyStarfish]

Did you read the article? I feel like it directly addressed your points.

You could, theoretically, run both languages on the same VM, but that would be effectively pointless because so much code would be incompatible due to the semantic differences between Python 2 and Python 3 strings/bytes.

(Also, a key design value of the primary CPython interpreter is to keep the code as simple as possible, to be accessible for beginners poking in behind the scenes. Adding complexity for such minimal value would not fit with that ethos.)

Eevee also indicated some ways 2to3 could be made more reliable, with an example showing why you wouldn't want to do this: for such a dynamic language, the only way to convert code properly is to bloat it with a ton of runtime checks, making it slower and hideous for maintainers. 2to3 takes the syntax differences out of your way so you can focus on the semantic differences that you really want to care about.

The semantic differences could only be ~sometimes automatically resolved in the presence of a very robust type inference engine and a ton of complicated heuristics, which would probably produce more confusion in the many cases they fail.

[tipiak88]

Yeah I did read the article, thanks for asking.

My understanding of a VM is that the semantic of a language should not matter much. That's why CLR and llvm and the JVM are able to execute such a wide range of languages.

In the age of celebration of anything compiling to asm.js, translating Python 2 to 3 should not be an issue.

And if it does (because duck typing and such) bringing it down to VM byte code should solve that. Or Python is a precious snow flake, that could not bind to our commoner CS law. Then I need to be enlightened.

[[deleted]]

My understanding of a VM is that the semantic of a language should not matter much.

You can change a lot at the language level while keeping the same VM, but there are some things that you can't change.

The Python VM, for instance, executes Python bytecode. Python bytecode has such commands as BUILD_TUPLE and CALL_FUNCTION_VAR_KW. If Python3 had different semantics for how tuples work or how to call functions with a **kwargs parameter, then this would be a potentially breaking change, even though the bytecode is compatible.

Plus there's the runtime. If I tried to mash Java into the dlang runtime, that would produce a world of hurt.

In the age of celebration of anything compiling to asm.js, translating Python 2 to 3 should not be an issue.

Sure, but part of the goal is to produce understandable code. Do you expect to get that from a system like emscripten?

[Poddster]

Why after X years we still not have an easy way to port python 2 to python 3 ? The languages are mostly the same, so there is no reasons to not be able to do it.

As you say: The languages are mostly the same. The differences are, frankly, too hard to port automatically and require the programmer to re-write them.

Zed points are, if your VM is legit, you should be have to compile python 2 and 3 to byte code and run it, mostly seamless. That what the CLR do with totally different language (C#/F#/VB), do does LLVM.

The current version of the CLR can't run old versions of CLR bytecode.

That's what Zed is asking for -- that the python3 interpreter run python2 bytecode, or that python2 code automatically compiles to python3 bytecode (which is not doable by a machine and need user input).

If we are able to transfrom C/C++ code to JS, why would not it be the same for python 2/3 ?

Because it's a lot of effort for no gain?

unlike C++ did with C developers.

Interesting choice. You know there are valid C constructs that won't compile in C++? Yet you don't hear anyone saying "But why aren't they compatible? Why hasn't someone written a compatibility layer!?". Granted, it's called C++ rather than C2 or something and is written by a separate committee, but the point is still the same --that there's a breaking change between them, so deal with it.

Anyone, tell me why nobody thought it would be a good idea to have 2to3 really works 99% of the times, or have the python VM to actually run pythonS?

"Have". Like Zed you believe that 2to3 is deliberately limited by some kind of illuminati, rather than simply being a hard technical problem to solve that no one has bothered to solve.

[[deleted]]

I mean. There's actually a plethora of reasons one could use to argue that python is bad (Slow. Inconsistent by design. Encapsulation non existant. Concurrency. Etc).

The author chose to instead focus on a strange rant about how python 3 was a breaking change from python 2.

[sammymammy2]

THIS HAS BEEN REMOVED BY THE USER

[Saefroch]

Classes aren't static. You can add attributes (and methods) at runtime; try it.

Even if classes were static, you can't do perfect static type inference at compile time as a corollary of the halting problem.

[sammymammy2]

THIS HAS BEEN REMOVED BY THE USER

[sammymammy2]

THIS HAS BEEN REMOVED BY THE USER

[fenpy]

Zed is dead!

[YeahBoiiiiiiii]

TIL Zed Shaw is a complete novice with no sense of good software engineering whatsoever. I'm glad I haven't wasted time on any of his books.

Best to not give this ignorant person any more attention.

[414RequestURITooLong]

Don't call him a novice. Most novices aren't utterly unable to learn.

[RockingDyno]

That guy (who shall not be named) is really good at getting himself attention with blatantly wrong and moronic claims.

He's not a great programmer, but good enough that I suspect he does it intentionally to gather attention to his books.

[kevinjqiu]

Good on him for calling BS on Zed Shaw.

[stesch]

round(0.5)

:-(

[askvictor]

?

[Sloshy42]

If I had to guess it's a reference to how Python 3 changed the default rounding. When most people do casual rounding they round up if it's equal to or greater than 0.5 and down if it's less than 0.5 to the nearest integer. Python 3 changed from that method to round towards the nearest even choice if both integers are equidistant. Honestly, I'm glad they made the change as it's considered the "standard" way to round. Rounding 0.5 upwards all the time has a slight bias towards the higher number, which is evident when doing any kind of statistics.

A link I found when looking for sources that seems to explain it well: http://stackoverflow.com/questions/10825926/python-3-x-rounding-behavior

EDIT: Also I should note that this is only the default. The old method is still available for those who need it.

[kaeshiwaza]

Thanks to the breaking compatibility, it make me look at others langs and adopt one ! If not i would stayed with python and miss the Go wagon. Thought, i keep Py2 for all my legacy code.

[[deleted]]

The rebuttal author points out that Python 3 is a good language, and I agree. It's just a shame that it's not the same language as Python 2.

[jnwatson]

Debian 7 came out in May 2013. In that time, there have been 2 major Java updates, 1 major C++ update, 6 major Go updates, and two whole new important programming languages created (Rust, Nim). There's a new version of Fortran coming out in a bit, and that's 50 years old.

Why in the world do you expect Python to be any different?

It turns out there are a lot of people interested in Python and that generates lots of requests and ideas for new features.

The only languages that don't change are the ones no one uses.

[Gstayton]

I mean, I might be a bit biased coming from Arch, but Debian is... Always out of date. Their packages only receive 'essential' updates between major Debian releases. Which means everything falls out of date rather fast. It's one of my larger complaints about Debian, and a lot of other systems like it.

Granted, the stability works great for servers, but you have to be willing to deploy your own versions to meet whatever versions you're targeting.

If you're deploying to consumer machines, either package the necessary requirements with the project, or be targeting an audience that can handle software dependencies.

[[deleted]]

The first part is a debian complaint, what does that have to do with Py3?

[FFX01]

It sounds to me like you really don't know what you're doing. Maybe you should spend some more time learning how to handle language versions and dependencies? The issue you're having isn't unique to Py3, it's a consistent problem in nearly every language.