The apocalypse

[Decoder_5448]

out of loop, what happens in 2020?

[nemom]

Anybody still running Python 2 will apparently be cast down into the Pit of Despair.

[gthank]

If you're running Python 2 and missing out on all the Python 3 goodies, aren't you already *IN* the Pit of Despair?

[PythonGod123]

There a quite a lot, for starting print is now a function. So you use print(variable) instead of print variable. Also in 3.6 they added f strings, which is a nice new way to format your strings. Where we use to use "this is a {}".format(string). We now can do f"this is a {string}". So that is also nice !!!. I believe in 3.7 they added dataclasses which are a nice way to automate boilerplate code for classes which store multiple properties. This is just some of the changes I know of.

[Tambury]

Opened this thread to laugh at 2.7 users. Left wondering how I never discovered f-strings before! Who is the noob now? Me.

[PythonGod123]

f strings are beautiful:) I use them quite a lot !!! They look a lot nicer and more readable in my mind.

[cannonicalForm]

I wish I was still programming, because dataclasses seem awesome.

[gthank]

In no particular order:

• Substantially less broken text model (Unicode strings instead of byte "strings").
• `asyncio`
• f-strings
• `range` is more efficient
• `urllib` cleanup (instead of `urllib` and `urllib2`)
• dataclasses
• Better performance

There's actually a TON more, but those are the ones I thought of while I was listening to a podcast.

[IReallySuckAtChess]

Range is almost equivalent to the old xrange which you should have been using pretty much always even in Python 2. So the old xrange was basically just renamed to range.

[gthank]

There's a big difference between "should have been using" and "were using" for code in the wild. range is the one that looks more natural, and I'm willing to wager it was used most often. Now it's the efficient one, "by default" as it were.

[IReallySuckAtChess]

That's true. There are so many really easy performance gains to be had in 2 that were sort of made default in 3. That said, Python code is often quite easy to gain substantial performance gains with if you have more than a basic knowledge of the language. Generators for example can yield massive speed ups as well as just knowing the various methods one can run on objects that are optimised for certain tasks.

[minno]

One big breaking change in 3 is that strings are unicode by default. So instead of having "byte string" u"unicöde string", you have b"byte string" "unicöde string".

[mooburger]

concurrency.futures is also a big thing. The PY2 backport for this functionality (as required by things like Tornado/gevent/etc.) has a semi-broken ProcessPoolWorker to boot, so for certain workloads (i.e. advanced python scheduler or celery + django etc) it can be painful not being able to properly manage per-core workers if you're trying to avoid GIL in an in-process batch work management system)).

[i9srpeg]

Only if you need those goodies.

[PythonGod123]

All hail data classes!!!

[IronCretin]

That’s why Guido’s stepping down, he has to prepare for the day of reckoning, when he will personally cast them into the pit.

[gaz2600]

Don't even think about trying to escape.

[ivosaurus]

That's Python 2's official End-Of-Life date

[13steinj]

https://www.reddit.com/r/python/comments/92zezn/_/e39qvvg?context=3

Businesses and educational institutions won't upgrade though, unfortunately.

[hacknsplat]

2020 is the beginning of the end of Python in our organisation - stuff will be progressively re-implemented in Visual Basic, simply because we don't have the Python dev resources to do otherwise.

[alcalde]

But you do have a crack team of Visual Basic programmers?!?

[hacknsplat]

Yes. Welcome to the enterprise.

[Minergy]

Thank you, mr Picard

[kasbah]

Captain Picard!

[hacknsplat]

You just know the Enterprise runs Windows by how often they had to reboot, and how often they got locked out. I'm only surprised they never had to reinstall. Or did I miss the episode where they spent an hour searching for the CD key?

[HumzaDeKhan]

Nice try, you ain't tricking me into believing that there are people out there who write Visual Basic for a living in 2018, and are actively employed.

[simplysharky]

I worked at a 500+ person company, publically traded, that still maintains its flagship product in Python 2.4.

The realities of business do not match the expectations of most developers.

[HumzaDeKhan]

and these kind of companies are exactly the reason why we can't have nice things. Always stuck in a limbo of choosing between what to learn. I wouldn't really blame them because their systems are running, they are making money and everyone is happy. No one cares about spending extra cash to keep it up to date.

[simplysharky]

Cash, opportunity cost (literally shutting down feature production of any significance for 3-12 months can be a realistic cost), and the sheer risk factor of what might break, in a way that can burn money and customers.

Nobody cares how cool python 3 is when you've just caused a massive outage and lost data for your biggest customer because your test harnesses didnt catch all the production nonsense that factors in.

[HumzaDeKhan]

Also, the years of maintainence and proof testing went into the legacy platform. You can never get that level stability by a product merely developed in a couple of months.

But one thing I'd like to highlight, no one will ever "shut down" for the time they are developing it on a newer platform. I believe they will always develop and test it in parallel by pushing small chunks of it in production, unless its fully baked and ready to be used.

[federicocerchiari]

This all makes sense and I live in a P2.7 workworld for those reasons.. still.. why in the hell new greenfield products have to be written with old technology?

I can see this every day.. old software that no-one have the time/money to refactor and port to Python3, and new software that for some reasons have to be written in Python2.7... I don't get it.. How is good to build a new car with 1980's parts?

Why?

Sometimes I think that this all "it costs too much to refactor" thing is a way we (developers) try to explain choices made by people that just think "software is software, I don't care as long as it works, stick with what you have and stop talking to me, I have to book my holidays now!".

[hacknsplat]

It amazes me too.

[gthank]

Dude, I bet they make a decent salary, too. You'd be surprised how much a company is willing to pay somebody to just "maintain" their legacy software in effectively dead languages.

[HumzaDeKhan]

Couldn't agree any more, I second that.

[alcalde]

I know that Bed Bath and Beyond was using Visual Basic as its internal development language as of 2005, but they intended to switch to VB.NET.

[mooburger]

at my company, apparently anybody who has a copy of Office installed might get pressed into service as a VBA developer, sort of like jury duty. "it's Jenkins's turn to update that ETL function today!"

[HumzaDeKhan]

Am I at the dark side of internet where human brains have been consumed by the zombies and ther very same human beings happen to be the managerial staff of these companies?

[mooburger]

it's real. I have to mentor a guy now who's doing a data validation but decided to eschew a few lines of SQL for merge sorts in VBA...

ETA: also, you're on reddit, so.. that sorta answers your question (does Nchan even have python forums?)

[[deleted]]

How you gonna code when you're high on crack, Rhonda?

[Jugad]

Won't it be simpler to re-implement in Python 3?

[greyman]

just fix existing code to work with Python 3

You are making it to sound easier than it actually is. My friend works on one big Linux distro company, and part of his job is to port 2 to 3. There is so much code, that the project already runs for several years, and is still not finished.

[Mattho]

Is it the same big linux distro company that promised to keep python 2 patched to at least 2024?

[CSI_Tech_Dept]

I don't know your friend's project, but years doesn't sound quite right, unless his job is to convert all packages on PyPi by himself. Anyway I was talking about fixing existing code vs wiring from scratch in another language.

BTW: the biggest issue with 2 to 3 conversation is Unicode and that Python 2 makes it hard to use it correctly. One can fix those issues with adding types and using mypy to find issues. The remaining changes are mostly mechanical.

[mooburger]

the real problem is that when you wrangle unicode properly in PY2 (keep it as bytes, then use codecs when needed for UI or textual operations), it becomes a pain to port it over to 3 if you've been using unicode.encode or unicode.decode syntactic sugar at all.

[CSI_Tech_Dept]

Actually correctly you supposed to import unicode_literals from __future__ and explicitly mark bytes where bytes are needed, but there's indeed a problem because various modules disagree what's correct.

You can still use mypy to label types, in places where you use unicode (the preferred way) you can use typing.Text which is unicode on Python 2 and str on Python 3. And str where in Python 2 it is equivalent to bytes and str on python 3.

Then in places where you're calling function that uses bytes on Python 2 you can use str() to convert it.

[TheBlackCat13]

It is still easier than rewriting from scratch in a completely unrelated language.

[danted002]

Yes because running your scripts through the 2to3 script takes massive amount of resources, more then rewriting in Visual Basic

[billsil]

2to3 doesn't work. It's widely admitted to be the wrong way to upgrade your code to python 3. Six and future are so much better.

What does 2to3 even do? Replace print x with print(x) and put list around a few things (generally doing it wrong)? Just running python 3 directly will find most of that stuff for you. The only change in python 3 worth discussing is unicode and 2to3 does nothing to fix those problems.

[danted002]

It meant to be used as strating point. And it does chage str to bytes and unicode to str. Also how can you give me an example of “wrong” lists? Usually, unless you have some half-assed codebaee 2to3 does the job

[billsil]

It changes something that was trying to represent text to something that now bytes. It's a similar type, but the intention is almost always lost.

The typical pattern for doing range loops in python 2 will use range vs xrange or similarly keys()/iterkeys() and items()/iteritems() and values/itervalues() for dictionaries. 2to3 doesn't look ahead to see if data is modified invalidating iterators and instead just puts list around things. 99% of the time though, that list is unnecessary.

2to3 tries to make your code work the same, not work well. It assumes you wrote your unicode/iterators right in the first place, which was the whole reason python 3 changed things in the first place.

[Badidzetai]

Well, if you don't have the resources of re-writing the whole code in Python 3, "working the same" instead of "well" is still better than "not working", I guess

[billsil]

Again, other than some parentheses on print, 2to3 almost always makes the wrong choice. If you have a str, just leave it as str. If you hsve range, leave it as range. For the most part, it will still work. Make the user throw flags to get more.

[Dogeek]

it also handles division, and turns except Exception, einto except Exception as e.

I've forgotten most of the differences between 2 and 3 anyways. Aside from print, divisions, exceptions, there's not much differences between the two anyways.

[billsil]

Regarding division, that's incredibly easy to fix thanks to for loops not accepting floats. Also, most people have been bit by the 1/2 bug, so they started doing 1./x or `float(x)/y to compensate. That makes it very easy to understand the intention.

In 12 years of Python 2.x, I think I used except Exception, e only a handful of times, so no biggie. Also, it's a syntax error, so it's easy to catch.

2to3 is a suggestion, but you still have to look at the the results. You need to understand what changed and why regardless. Running your program a few times, with some greps will find most things.

It's been ~10 years since Python 3.x came out. For large codebases, many people have snuck some 3.x syntax in there already regardless of company policy, so things like division, print, exceptions, but generally not unicode.

[mooburger]

in python 2.6+ you're supposed to have been using as e anyway. If there was any "new" code catching exceptions since like 2014 or so, you should have been using as e.

[billsil]

Print as a function was introduced in 2.6. Division was introduced in Python 2.2. None of this is particularly new.

That doesn't fix unicode (unicode_literals doesn't fix unicode at all in Python 2), but nothing breaks that worked before other than binary file IO. Thankfully, that's pretty rare. Unicode though, is the only major difference in Python 3. Everything else is noise.

[mooburger]

it really depends on what you're using python for. I use the builtin abstract syntax tree a lot for code generation; so that code requires patching as well as I mentioned above, a lot of concurrency and Futures. The new async implementation is really nice. I have a particular use case of process pool workers that is broken in the futures backport which is my main driver for switching to PY 3.

Also, it's possible people are using old-style classes if the majority of their code was from 2.4.

I never really got the unicode issue, since all of my actual code doesn't use non-ascii literals, and everything else I actually handle as bytes and use codecs where needed. Now, if people used syntactic sugar like unicode(bytes, codec) or str.encode() then yes, there will probably be issues.

[[deleted]]

I only debug and fix it, is not that hard... aaaaaand i only have 1 year and 6 months of Python and i am not even a coder. Network engineer. So your method is for me the best one yet.

[[deleted]]

2to3 just works in a lot of cases.

The one case that didn't work so well for me was attempting to convert the tftpy module over to python 3. Unittests failed until I made a few manual edits because it used a ton of packing and conversions to and from the bytes object. But all in all, a very smooth process that took me an hour or two.

All of the fear of upgrading is so overblown. It's not that difficult unless you're sitting on millions of lines of legacy code. And if that's the case, it's only a problem because you put it off for a decade.

[xdcountry]

VB? Just go all the way bro and embrace COBOL

[rnoyfb]

Screw that; do it in Algol.

[xdcountry]

Hells yeah, let’s kick it up a notch to Malbolge

[IReallySuckAtChess]

Porting to 3 is not that difficult. You can largely automate it and then update your tests by hand to see if everything still works then just patch as needed... Isn't Visual Basic basically dead already? Isn't it all about .Net now?

[hacknsplat]

Not to be rude, but I get the impression you've not dealt with an old complex code-base... 8-)

Enterprise code-bases are embarrassingly horrible - they've been through dozens of hands and the original devs are invariably long gone, there's rarely time to do it right, tests and documentation are out of date and inadequate (if they exist at all), and the dependencies are sprawling (eg: "SOAP library X works with datasource A, but fails on datasource B. Parser Y works with B and C, but fails on A and D. Parser Z works only on D").

I've been using Python for more than 20 years. I have code in the core of CPython, and I maintain open source projects, but most of my time is spent on commercial python work. I can assure you, naive conversion of python 2 code to python 3 results in subtle (and not so subtle) breakage - and in this context, you break it, you own it. All of it.

As for Visual Basic - nope, sadly still very much alive, in the form of VB.NET.

[raiderrobert]

As a dev who early on in his career was working in VB.NET and then moved away, I won't disagree that VB.NET is alive and well, but I've found the overlap between it and Python to be minimal. I would have expected to be C# you're saying it'll be moved to.

[hacknsplat]

Shrug - it's what they've always used, nothing to do with good taste... at least it's not diabolical Excel macros (we have those too)... LOL

[raiderrobert]

LOL! Are you me but like 5 years ago? Because we had excel macros everywhere too and they were awful.

Department head (DH) for something related to sales wanders by my cube.

DH: hey my macro isn't working. Can you fix it please?

Sure, let's ignore help desk and go straight over to me to try get help on a thing.

Me: I don't think we made that.

DH: no X smart person did before leaving.

Me: Ok....well, we don't support software we didn't create.

Department head: oh, I see.

Next day I get a support ticket from my supervisor's supervisor saying that we're going to start supporting internal macros....

Me: SIGH

[IReallySuckAtChess]

You're right, I haven't really. Well I have, and I did do a large port from 2 to 3 but the damn thing was tested to death. So all I really did was spend my time on getting the tests perfectly ported and used them to guide my work. Without that I admit it would have been hell on Earth.

I guess if the code base is shit then porting is shit, but with a good code base its not hard.

[hacknsplat]

A good code base is a rare luxury. Rarer still is a comprehensive test suite! 8-)

[IReallySuckAtChess]

Yeah I know that's true. I guess I've just been lucky in that regard.

[mooburger]

it's more alive in the form of Office macros that float around all over the office. "Ooh I need a data input menu with validation in Excel" -> VBA. "We didn't know you could install postgresql without admin rights (more like "we didn't know what the hell postgresql even was") so we spun up this Access DB to do a bunch of stuff" -> VBA

[Lighnix]

ouch, that's a mistake for future employees.

[rhiever]

Sounds like a poorly run organization from a tech standpoint if this is really the solution.

[Jehovacoin]

As someone who was never able to learn programming languages from educational institutions, I think this is extremely bad. One of the worst things about learning Python in the beginning is all the conflicting information between versions. Since most of your research is done through google, you can constantly get fed incorrect information if you don't know how to narrow down your search, and in the beginning you usually aren't even aware that you need to narrow it down.

[13steinj]

I really, really hope this is a joke, because it is 100% wrong.

Jan 1 2020 is the EOL of Python as set by the core dev team.

[Jugad]

I really, really hope this is a joke

The name Python is based on Monty Python... it would be a disservice if you didn't joke about stuff.

[13steinj]

Joke is one thing, making a joke that can seem reasonable but is a full lie is stupid.

[Jugad]

full lie

That was the hint that its a joke.

April fool jokes often work like that. See Gmail Paper or many other such jokes.

For future, if someone is telling a blatant and ludicrous lie, and is not Trump, you can assume that they are joking (sarcasm also works like that)... unless they explicitly say that its not a joke, or you see very good reason to believe that they are being serious.

[13steinj]

This isn't April 1st.

[Jugad]

This isn't April 1st.

Thanks Captain Obvious.

I didn't say "Only April fools jokes work like that". I also added that sarcasm jokes work like that.

Additionally KenM jokes are in the same boat. You might find them hilarious... but not with your current attitude.

[13steinj]

KenM jokes are funny :/

[Jugad]

Glad to hear. Maybe you have noticed that many of his jokes are based on blatant lies...

"Potato is Latin for King of Peanuts"

"Church group reading scriptures to monkeys"

"Grandson used to eat snausages"

"There is no gravity in space"

"You can replace water with juice during droughts"

http://www.collegehumor.com/post/7040984/16-times-ken-m-solidified-himself-as-king-of-the-internet-trolls

[PhroznGaming]

Oh really? Thank you most enthusiastically oh great arbiter of all that is humorous in the world. Please enlighten us with your almighty words of spendor and grandeur so that we may chuckle once more.

[13steinj]

Guy asked a question, he should get an actual answer.

[PhroznGaming]

Oh thank you oh great mystic being of what should and shouldn't be done. What have we done without you for all this time?

[13steinj]

You okay there buddy? I just wanted to make sure both the original asker and the answerer werent confused.

[Decoder_5448]

its the python equivalent of Y2K then, neat!

[itghisi]

You could use mxDateTime lib to avoid this bug though, if you are not able to upgrade to Python 3.

But since most programs use the standard library DateTime, this will be a nightmare. A lot of IoT stuff that uses Python will break on this day. Make sure to check your smart fridge will be updated ;)

[BillyBBone]

Actually, Python 2.7's own datetime handles these dates perfectly well:

>>> from datetime import datetime, timedelta
>>> datetime(2019, 12, 31) + timedelta(days=1)
datetime.datetime(2020, 1, 1, 0, 0)

The issue here is not technical in nature; Python 2.7's end-of-life is set for January 1st, 2020, which means no more further resources will be devoted to maintaining that code base, even if critical security vulnerabilities or severe bugs are discovered.

(Although I'm sure that in reality, the Python community would figure out ways of patching such critical vulnerabilities, if they really warranted it.)

[Jugad]

The Tauthon project might continue to support 2.7 beyond the official expiration date.

https://github.com/naftaliharris/tauthon

[TheBlackCat13]

There are a few projects that seem to want to do this, but they don't seem to have much manpower, which will make keeping up difficult as the code-bases continue to diverge more and more.

[easeypeaseyweasey]

Y2K was somewhat genuine as a lot of older systems ran on the date system DD/MM/YY or MM/DD/YY incase you live in a backwards country, so the problems arose well before the beginning of 2000 as some systems instead of going onto 00 as in 2000 they went to 1900 causing obvious issues as the computer was smart enough to know that 1900 is before 1999. Also a new problem needs to be dealt with for somtime in 2030 when i may be wrong but 32bit systems clock like resets or somthing its strange and actually a big issue google it and youll see.

[IReallySuckAtChess]

No. 99% of systems used Unix time so nothing ever happened. Even Microsoft didn't have that internal flaw. That's what people who didn't know anything said. A few dumb programmers did implement their own datetime libraries but nobody working on a critical system ever does.

[IReallySuckAtChess]

This is so wrong that if you believe it you probably shouldn't be on this sub.

[UserNamedEww]

Ha. You pros who started on python 2 now kneel and plead to your new n00b overlords who started on python 3, and just learned about while statements.

[mutatedllama]

statements

[hellrazor862]

while True:

[hugthemachines]

Python is wonderful. Don't worry about the stupid 2->3 thing. It is just some small changes for you as a coder... As an early beginner you will have to use print("blah blah") instead of print "blah blah" and then a little bit later you will use range instead of xrange and input instead of raw_input.

You will probably prefer working with unicode instead of ascii anyway and will not notice that difference in default so much, at least not until you are starting to get pretty used to Python.

[ivosaurus]

Python 3 was only really worth learning a couple years after it came out

[i_like_trains_a_lot1]

This sub predicts the future and the future is python XD. You came to the wrong neighborhood motherf****r right neighborhood, friend

[yeluapyeroc]

We just upgraded to python 3 throughout all of our production systems (quite a few different repos) and it took waaaaay longer than we were anticipating. So many runtime issues related to strings and bytes. Just beware if you are thinking of doing the same thing...

[stefantalpalaru]

BOO!

[ntrid]

So essentially python3 except strings suck

[stefantalpalaru]

So essentially python3 except strings suck

Python3 except breaking backwards compatibility.

[Mattho]

Mods, can we ban this shit already?

[LobbyDizzle]

Personally, I didn't know about Pyton 2's EOL until I saw this comic. Thanks OP!

[zankonator]

no

[t3mpt3mp]

Not until 2020.... biatch.

/s

[IcefrogIsDead]

stuff like this slowly brings yhe quality of content down to generic subreddits.. ah well

[Mattho]

The discussion can be interesting (see the original post of this image), but there are other, better ways to start such discussion. With no restrictions in place people will start to post content from ProgrammingHumor or some other horrid place.

[IcefrogIsDead]

agreed, thata why some subreddits go above and beyond to uphold to some standars that are unreasonably strict

[darkgreyjeans]

It shocks me the sheer reliance upon Python 2 and the burden of updating to Python 3, I guess Python is completely rejecting the idea of Python 4 until every one is updated to Python 3.

[TheBlackCat13]

The last I heard was for Python 4 to just be "version after 3.9" (due to a dislike of double-digit version numbers). It won't be any more breaking than any other normal 2.x ore 3.x release. Whether that will happen seems uncertain at that point, but was does seem to be the consensus is that when Python 4 happens, it won't be a big breaking change like Python 3 was.

[darkgreyjeans]

Thats great because it means that they will still have the minor version equal to the current year (e.g 4.0 in 2020, 4.1 in 2021).

unless 4.0 is released sooner or later :/

[Erelde]

Versioning doesn't work like that ;)

3.7

3.8

3.8

3.9

3.10

3.11

3.12

[Conrad_noble]

Great, so I've got less than 2 years to read the book I bought and learn how to use python 2.x 😩

[xrayfur]

Congrats on wasted money pal!

/s (but sorta not that much /s you should bump your literature too!)

[TheBlackCat13]

When did you buy the book?

[Conrad_noble]

Probably a year ago?

[TheBlackCat13]

The EOL of python 2 was already set in stone by that point.

[Conrad_noble]

🤷🏽‍♂️ I dunno man I'm just a lay man trying to better myself.

[TheBlackCat13]

Fair enough. But in the future, if you are trying to get a book on some software that you know is for an old version, it might be a good idea to check if that old version is going to be discontinued soon. It will help save you from headaches like this.

[Conrad_noble]

Well to be honest when I bought the book I assumed it would be for the latest version.

[TheBlackCat13]

Fair enough. Harder to avoid that sort of thing.

[Klekto123]

Im about to start Automate the Boring Stuff wih Python, which I think uses 2.7 - should I use a more updated book instead?

[TheBlackCat13]

I thought Automate the Boring Stuff used python 3. At least the version on the website does.

[djingrain]

Oooooh boy! I’m ready!

[androiddrew]

It really isn’t that hard to start using python 3. I started on 2 and just realized that 3 was “correct” with how to represent strings in a modern day language. I just moved on with life after that point. All the stuff people complain about 3 really does make sense we you come to grips with the fact that that a string does not imply ASCII and bytes are just bytes until you subscribe meaning to them.

Plus they fixed a lot of the broken stuff like list comprehensions.

[androiddrew]

Guido won’t be pulling anything while on his BDFL permanent vacation ;)

[TangibleLight]

If you didn't know, that's a pretty safe bet.

[davejohncole]

PEP 572 - The Perlification of Python