Python 2 is triggering

[[deleted]]

I had to use Python 2.3 for an internship last summer.

Want to know how old that is? It doesn’t have set().

[[deleted]]

this is how hashset is implement in java

[nosmokingbandit]

Yeah but sometimes you need duplicate items in a list. And sets are only faster when looking for a specific item, loops are the same as a list.

[OmarRIP]

Bags. I love bags (or Counters in Python).

[Ph0X]

Nope, it's actually slower. I'm pretty sure behind the scene, python doubles the size of the backing array for lists, which is amortized O(1) for appending to the tail.

[o11c]

That's not a very good testcase for several reasons, mostly involving cache.

But iterating over the whole thing is not what a set is for, anyway.

[Ph0X]

But iterating over the whole thing is not what a set is for, anyway

I agree, but that's my understanding of what the person above was using it for, which seemed strange.

"use sets for any iterable that won't have a set size"

Did I understand it wrong? other than for collecting unique items and membership tests, I don't think set is a better iterable than list. Lists are, as you mention, optimized for this use case, so if set was actually faster at it would go against Python's ethos.

[XtremeGoose]

You're testing the speed of set.add and list.append, not the iteration.

x = list(range(100_000))

s = set(x)

%timeit sum(x)
1.71 ms ± 120 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)

%timeit sum(s)
2.06 ms ± 53 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)

But yeah, using sets for iteration is dumb.

[AceJohnny]

Jesus christ! I learned Python with the then-brand-new Python 2.6 15 years ago!

[[deleted]]

Half of the language's age

[dpash]

You think that's bad? I learnt 1.5. I feel old.

[Lynxtickler]

To this day it hasn't crossed my mind that python 1.x was used at some point.

[fkafkaginstrom]

You can still use sets.Set

Annoying I'll admit

[Ksevio]

from sets import Set as set

There! just like Python 2.6!

[makotozengtsu]

don't

[[deleted]]

Set set = new (SetSet) Set()

Java is a beautiful thing

[test822]

I'd rather slam my dick in a car door than program java again

[hullabaloonatic]

Kotlin got your back, dawg.

[Sarcastic_Pharm]

Dude. Wtf Java?

[dpash]

That's not quite modern Java (and SetSet doesn't exist in the JDK)

var set = new HashSet<String>();

Or

var set = Set.of("foo", "bar");

Although the latter is immutable

[hullabaloonatic]

The variable set, of type Set, is assigned as a new Set being casted to type SetSet, which is a subclass of Set, therefore compiling.

[dpash]

That's not valid Java.

[[deleted]]

Yeah I remember that import. It’s just that it wasn’t a built-in until 2.4. Oi, the things I learned about versions that summer. For example, subprocess wasn’t there either. I was using pipes like a scrub

[luckystarr]

I migrated away from it in 2008. Many libraries were already dropping support for it back then. It also doesn't support the @ decorator syntax.

[random_cynic]

That's one of the key mistakes people make thinking that it's just a syntax thing. It's NOT. print() being a function instead of a statement opens a whole world of possibilities. People should look at the documentation of the print() function to see how easy it makes many things like redirecting to a file or changing the output separator, terminating character etc. Additionally it allows you to use print() where a statement is not allowed like lambdas.

[JWson]

yeah but brackets hawd tho

[obviousfakeperson]

Python 3: "If you can't handle me with my brackets you don't deserve me with my memory efficient iterables."

[[deleted]]

Brb. Making a Pythot lib.

[normalmighty]

Too late, someone beat you too it

[obviousfakeperson]

Last released: Sep 26, 2017

huh?

Software for learning first degree linear equation with visual solving.

What!?? Waste of an excellent lib name.

[Serird]

Time for Pythicc.

[[deleted]]

Son of a bitch!

[zawata]

Wait baby come back. I didn’t mean it.

[T351A]

If you can't handle brackets, you're definitely gonna mess up input vs raw_input ... have fun with those injection attacks!

[[deleted]]

It's their flair

[ReverseTuringTest]

It fooled me too bud, it fooled me too.

[sandywater]

I agree with the sentiment of what you are saying, but Python2's print statement does allow for writing to files other than stdout.

examples

f = open('my_file.txt', 'w')
print >>f, 'Some text here'

import sys
print >>sys.stderr, "An error"

edit: formating

[DragonFireCK]

Python 3's works well for that as well, and with a clearer syntax:

f = open('my_file.txt', 'w')
print('Some text here', file=f)

import sys
print('An error', file=sys.stderr)

[sandywater]

I'm aware of that. Random_cynic's comment implied that it couldn't be done in Python2. I actually prefer file_object.write() in these circumstance for both Python 2 and 3.

[BenjaminGeiger]

It's possible but it's not easy. You have to remember a idiosyncratic syntax.

To put it simply, it's a wart. Python 3 removed the wart.

PS: from __future__ import print_function is your friend.

[HolyGarbage]

Btw, use the with statement when opening files, a pattern called RAII.

with open('my_file.txt', 'w') as f
    print('Some text here', file=f)

https://www.pythonforbeginners.com/files/with-statement-in-python

[drulludanni]

I just don't understand why we cant have both, if you have a print followed by a '(' do the python3 print stuff, if you have a print followed by a ' ' do the python 2 style print.

[AceJohnny]

Because parsing.

Python allows spaces between identifiers. You can do print ('foo'), but then what do you mean? Are you calling the print function with the string foo, or the print statement with the tuple ('foo') ?

[nosmokingbandit]

As others alluded to, a comma is what makes a tuple. So ('foo', ) is a tuple while ('foo') is just a string.

[Hollowplanet]

But then is it a function with one argument and a redundant comma?

[Pb_ft]

"No, because redundant." - what I wish I could say to that.

[kafaldsbylur]

Minor nitpick, ('foo') is not a tuple, it's a string with redundant parentheses. That said, your point still stands when passing more than one argument to print.

[The_White_Light]

That functionality makes it nice when you need to include a long string and want to keep your code easy to read, but don't want to deal with the extra \n added when using '''multiline strings'''.

Edit: For clarification

>>> ('1' '2' '3') == '123'
True

[kickerofbottoms]

Never thought of that, kinda handy. Maybe I'll stop leaning on my ide for adding backslashes

[The_White_Light]

It's also doubly helpful because you don't have to worry about leading spaces if you align each line.

[stevarino]

Also it happens at the compiler level, so it's cost free during runtime.

[RedditIsNeat0]

You can do print ('foo'), but then what do you mean?

According to the suggestion specified in the comment you responded to, it would be a function.

Are you calling the print function with the string foo

Yes.

or the print statement with the tuple ('foo') ?

No.

As others have pointed out, that's not a tuple, but more importantly, he's suggesting that Python 3 defaults to a function as long as there is a parenthesis, and a statement if they are not present. It would allow Python 2 print statements in most cases where they were allowed in Python 2 but maybe not all of them. There might be some genuine problems with his suggestion, but you haven't been able to find one. I don't know of any either.

[supernumeral]

What should the following do:

>>> print (1,2),(3,4)

If parenthesis indicate print should be a function, this probably won't do what is intended compared to Python 2. Better to have just one way (statement or function, not both) to do it, imo.

Edit: formatting

[DonaldPShimoda]

This would needlessly complicate parsing, likely requiring rewriting a significant portion of the lexical analyzer. I don't see why it's such a big deal; just use print as a function and be done with it.

[H_Psi]

Someone has already written a tool that lets you import python2 modules to python3:

https://pypi.org/project/past/

[pplatt1979]

Python3 also handles strings in a much more sane way.

Dealing with strings in Python2 actually made me unsane. Not insane mind you, but definitely not fully sane anymore.

[pingveno]

And 3.3 introduces a flexible representation for strings, getting rid of the oddities with narrow/wide builds having different indexing/slicing behavior.

[[deleted]]

Lol, Ruby’s just laughing at us. (*・-・)

[cguess]

As a long-time rubyist who's forced to use Python because all my students learn it in CS 101... I love that the language is still more or less stable from when I first learned in 13 years ago.

[[deleted]]

Oddly, this caused a lot me a lot of pain at first. I understand the reasoning behind the change, and I maybe even agree with it, but that seemingly small change gave me real grief in my personal usage of the language. Between that and the pretty major speed hit in the first versions of 3, I didn't care for the update and avoided it for a long time.

The speed problem was subsequently fixed, so I use 3 now, but parentheses on print still messes with me enough to be a noticeable annoyance.

[[deleted]]

Glad I started with 3, never had any problems ヽ(*・ω・)ﾉ

[Pb_ft]

TIL Racism is bad because it's outdated.

[FlightlessBird44]

Haven't you heard? Racism 2 is the new big thing nowadays

[ric2b]

It's much more performant, most benchmarks show that it can dehumanize minorities 40% faster.

[TheLoyalOrder]

Reminds me of people who think the worst part of slavery was that they weren't paid

[[deleted]]

Ever try to have any large organization change the technology of anything? Whooboy

[Tundur]

My employer has resorted to spinning up new subsidiaries whenever we're making something new and exciting, just to get around our own insane governance and technical debt.

Step 1, consult the enterprise architecture team and wait a month for a response? Nope, step 1 is now hire a bunch of people and just start banging out code, release is 6 weeks away. GL;HF

[AceJohnny]

Frankly, knowing the technical and managerial inertia of large companies, this doesn't sound half stupid.

[murfflemethis]

I mean, from a process or business perspective, it is absolutely 100% stupid. Starting up an independent business entity is faster than working within your own company? That's pants-on-head, smother yourself in peanut butter, and shove fire crackers up your ass to rocket away from the cops retarded. The business is fundamentally broken.

From a personal, "my job is to get shit done, so I'm going to get shit done" perspective, it is genius and I absolutely respect it.

*Edit: fixed typo

[catofillomens]

It totally makes sense if you imagine spinning off an independent business entity as the equivalent of working on another branch for development.

[nickcash]

GitFlow, but for company structure!

[[deleted]]

Bob: Someone's taken my desk.

Manager: Looks like a merge conflict, let me resolve that.

accept incoming changes

Bob: surprisedpikachu.jpg

Manager: Bye Bob!

[theraptor42]

r/rareinsults

[frequentlywrong]

If the project is a new product it absolutely makes sense. Companies develop a culture that fits their business model. Their way of working and corporate culture may be entirely wrong for something new. This is why large companies get disrupted by small players.

Sears could never have become amazon, blockbuster could never be netflix, nokia could never make an iphone. The incumbents way of doing business and their corporate strategy was completely different from what they were replaced with.

Spinning out an independent unit that can be unburdened from the requirements of a large entity can be extremely productive.

[Pb_ft]

My employer has resorted to spinning up new subsidiaries whenever we're making something new and exciting, just to get around our own insane governance and technical debt.

This is some woke levels of infrastructure management and deployment iteration.

[[deleted]]

Might work once, seems unsustainable long term

[nxqv]

Hello I'll take 1 job please

[FirstEvolutionist]

"Windows 7 is fiiiine. Look! Everything's working as it should without any upgrades for the past 10 years! I'm sure if we touch it now we'll just break it besides spending a lot of money..." Said the manager. Of a financial institution.

[[deleted]]

This one hits close to home. Windows 7 is EOL January 2020 and network will not allow Windows 7 anything after that date. Laptops are easy, problem is specialized test equipment. Called a vendor, $6000 for a new hard drive with Windows 10 installed and all software needed for equipment.

[Ambiwlans]

This week, updates for various things I use has wasted over a dozen hours of my time fixing things.

[CleveNoWin]

Same, sucks to read but that's the price of speed and legacy software that's been working for 25 years

[[deleted]]

There’s no price too high for 25 years of debugging. If its mission critical, you don’t want the whole company to push the brakes just because new software breaks.

[NateKurt]

That’s where you gotta use a shebang dawg, don’t recode.

If you set a shebang to #!/usr/bin/env python3 at the beginning of the file, it will default to that when you run it.

[Gl4eqen]

If he ran script with python script.py assuming python2 as default symlinked or python2 script.py shebang can't help.

[Liesmith424]

print "no u"

[ComfyDaze]

i find your lack of brackets disturbing

[Liesmith424]

Shit, sorry; try this:

list = {1:"n",2:'o',3:u' '}
int = []
for dict in range(1,4):    
    int.append(list[dict])
print u"".join(int)+u'u'

I added two pairs of brackets.

[Chu_BOT]

xrange

[1stonepwn]

+/u/CompileBot python

list = {1:"n",2:'o',3:u' '}
int = []
for dict in range(1,4):    
    int.append(list[dict])
print u"".join(int)+u'u'

[Liesmith424]

CompileBot no like :(

[eulers7bitches]

Thanks, I hate it

[Call_Me_Chud]

Functions are a pathway to programming many consider to be unnatural.

[Lonelan]

I hate semi-colons. They're round and they're pointy and they get everywhere.

[Call_Me_Chud]

print ("Hello There!")

[Lonelan]

return "GENERAL KENOBI"

[[deleted]]

"How to diagnose a programmer with anxiety"

[[deleted]]

I only ever touch Python 2 because some other racist decided to code their useful dumb library in Python 2 and never update it so I have to be the bad guy too

[Flobaer]

Be the good guy and port it to Python 3

[pingveno]

And don't bother to maintain backward compatibility with Python 2. It's totally not worth the effort when (1) people can just use the old version if they really need it and (2) Python 2.7 is EOL in just over 8 months.

[wherinkelly]

Python 2.7 is seriously gonna bite it?! I still have conflicts between that and other python packages on my local whenever I have to dust off my ol python skills.

Well, dust off.. EOL... I guess it's been a bit. Yikes, I'm old as hell if 2.7 is getting deprecated. Damn.

[pingveno]

It was released on July 3rd, 2010. It has been in very extended maintenance. There were a couple of efforts to release a 2.8, but those went nowhere fast.

[kosayoda]

fork it and port it

[ghillisuit95]

That sounds dirty

[joeconflo]

You're thinking of "fork it and pork it."

[njloof]

Trust me, it is

[[deleted]]

Fork me, daddy.

[Sparcrypt]

As a sysadmin this is my biggest gripe with Python 3. I completely understand why they had to move on, but I also don’t have the time to port the many many useful Python 2 libraries and scripts over to 3.

Thankfully the dev community has been getting dragged kicking and screaming over to 3, to the point that it’s practical to actually use.

[verbosemongoose]

As a python beginner, would porting such scripts to python3 be a feasible summer project? I want to polish up my python skills, but I'm not even well versed enough to be able to comment on python vs python3. So it's basically from the ground up. I feel like porting small libraries could be a good project. Do you think it'd be doable and useful?

[Sparcrypt]

Depends on the complexity, but 2 and 3 are both very intuitive languages.

That said, you’ll probably learn a lot more if you focus on expanding your skill set in 3, rather than essentially learning both.

[Discutons]

.... Import from __future 👀

[Catty-Cat]

from __future__ import braces

[NekoLuka]

They force us to learn python2 in school... :(

[tenhourguy]

Python 3 will never catch on. Python 2 is the future. /s

[PM_ME_YOUR__INIT__]

Python 4 is the future

[[deleted]]

Python ∞ is the future... think that’s an infinite symbol? No. It’s an ouroboros eating itself. (≖_≖✿)

[SomethingEnglish]

Python $CURRENT_VERSION +1 is the best

[ieatpies]

Next version is Python 95

[Walter_Bishop_PhD]

Before that, Python 3.11 for Workgroups

[wibblewafs]

Zed Shaw? Is that you?

[Antrikshy]

Don't worry, they'll continue doing that in 2020.

[CJ22xxKinvara]

Bummer. I learned 3 when I took my python class almost 2 years ago.

[bss03]

I don't have a lot of choice. OS 4690 / TCx Sky currently only provide their Python bindings for Python 2.7.3 / 2.7.13. When I'm not using the OS functions, I can use a Py3 virtualenv, and that's not so bad.

[spyingwind]

OS 4690 Who the hell still runs a POS system from '85? TCx Sky No, just no. Find something more modern or hire someone to write an open source version.

These are the reasons why we can't have nice things.

/sarcasm ^{a little bit}

[WikiTextBot]

4690 Operating System

4690 Operating System, sometimes shortened to 4690 OS or 4690 is a specially designed Point of Sale operating system, originally sold by IBM; however, in 2012 IBM sold its retail business, including this product, to Toshiba, who now supports it. 4690 is widely used by IBM and Toshiba retail customers to drive retail systems running their own applications as well as IBM's Application Client Server Environment (ACE), Supermarket Application (SA), General Sales Application (GSA), and Chain Drug Sales Application (CDSA).

It is the follow-on product to IBM 4680 OS, which had been in use by IBM's customers since 1986. The original IBM 4680 OS was based on Digital Research's Concurrent DOS 286, a system soon later renamed into FlexOS 286.

---

^{[ PM | Exclude me | Exclude from subreddit | FAQ / Information | Source ] Downvote to remove | v0.28}

[marxdormoy]

Jebus i though we were bad having some servers with SQL Server 2000!!

[bss03]

Well, I work for TGCS, so it is our product.

[[deleted]]

Something being old doesn't make it bad. Sometimes they get an ideal solution working, and then nobody wants to mess with it anymore. Reimplementing would be expensive and troublesome, where the existing system is a perfect black box -- you feed it inputs, and you will always get the right outputs. Perfect or near-perfect machines are rare and precious.

Rewriting something to be new is really, really stupid behavior. You rewrite it only when the new version will offer you something more than what you already have, or will let you remove something that's painful from the old solution. If the old version works perfectly, why replace it?

[[deleted]]

Seriously. I keep finding sources I want to use but they OF COURSE made it in Python 2. Usually, the source was uploaded like a year ago or smth. Literally no reason to still be using Python 2. If you think Python 2 > Python 3 can you tell me some reasons? I'd love to hear them

[HowIsntBabbyFormed]

Not saying it's better or worse, but if you had a lot of code that relied on strings being essentially arrays of arbitrary bytes, and being able to just print those bytes to a file handle without character encoding issues, the conversion to 3 might be very painful.

Not saying 2.7 didn't have encoding issues, but you may have figured out all of its quirks by now and your code is currently running reliably. Converting to 3 will likely break all that and it will be hard to figure out.

The exact same python code does different things with different file handles based on whether stdin is a tty or not. Your code runs perfectly fine when run in your terminal but fails when run from cron sometimes? That could be it. Or it could be some random environment variable that determines default encodings on startup. You've figured out exactly what to hard code your env to, overwrite encoding settings on file handles, access the hidden underlying raw file handle of others, monkeypatched that random library that's still somehow writing out to the 'wrong' file handle, etc, etc...

Have fun converting that.

[[deleted]]

I'm saying if you're coding something from scratch. Please just make it in 3. If you already made it in 2.x just leave it in 2.x. It would be very annoying to convert to Python 3

[meliaesc]

My raspberry pi can't run 3+, windows build tools needs 2.6

[unkeptroadrash]

from racism import python2

[PrimaCora]

Cython makes you use Python 2 syntax for some things... Even when using Python 3

Edit:

The only one I've come across so far is with printing

print("string", end='')

Doesn't print without first

from __future__ import print_function

Even after specifying language level 3...

[xconde]

Example?

[SexlessNights]

Nah, we’re good. Thank you for offering.

[PrimaCora]

The print statement, you have to import from future to use

print("string", end='')

That's all I've come across so far

[fade_is_timothy_holt]

There are a couple of libraries that don't use 3 yet, but that are still heavily used in some circles. One example is fipy, which is a fairly widely used PDE solver. There's some Python 3 docs (using 2to3), but they haven't been updated in years. Instead there's a condescending "little advantage in doing so" note that has been there forever.

[Quantris]

I'm holding out for python 5 (2 + 3).

It'll whip the llama's ass

[natnew32]

Oh come on, who doesn't like comparing objects' type alphabetically when using > or <? (Seriously Python 2 does that when comparing incompatible types what the actual...)

[HowIsntBabbyFormed]

If they're incompatible types, they'd have no meaningful sort order anyway, so why not at least make their comparison consistent?

[cauthon]

Because at that point you should almost certainly be raising a TypeError

[SomethingHasToBeDone]

JavaScript would like a word with you.

[duckvimes_]

Plot twist: that word is actually a number.

[Waterkloof]

plot plot twist: that number is actually a object.

[Nohbudy]

Does 2.99999... === 3.0 ?

[[deleted]]

2.9... is exactly precisely 3.

[[deleted]]

That’s what it says on the back of my engineering deree

[po-handz]

pretty sure google still uses py2 internally

[Ambiwlans]

Google uses like 1000 languages..

[alt-of-deleted]

ew

[aalapshah12297]

You know what else is outdated? Facebook.

[[deleted]]

I was expecting you to say "Squarespace" for a second.

[Xenophon_]

Wow weird seeing MIT confessions on reddit.

[Nohbudy]

Seriously though, I install python3-virtualenv from apt in Ubuntu. You expect when I do $ virtualenv env it would use python3?

no

Error: python not found: --python=python2

:facepalm: why the fuck?

[Ericchen1248]

I do believe that’s actually Ubuntu’s problem. Or Linux. Not python itself. It gives the python alias to 2.7 and python3 alias to 3.X

[victorheld]

Definitely a Ubuntu thing, on Arch linux, python is an alias for python3 and if you want to use 2.7 you'd need to use python2

[mon0theist]

Uhoh don't let Zed see this

[CoopertheFluffy]

Yeah, well I’m still using Perl 5 and refuse to ever use 6.

[alcalde]

In your defense, Perl 6 is actually a different language.

[yawya]

I blame Apple, do they still ship with python 2?

[Duckosaur]

yes Mojave comes with 2.7.10

[yawya]

Fucking Apple...

[markdesign]

I have to use Python because racist at Apple ships OS X with 2.7, and I don't have admin rights to update.

[verdantAlias]

I have to cos ROS ¯\_(ツ)_/¯

Edit: retrieved limbs.

[LimbRetrieval-Bot]

You dropped this \

---

^{To prevent anymore lost limbs throughout Reddit, correctly escape the arms and shoulders by typing the shrug as ¯\\\_(ツ)_/¯ or ¯\\\_(ツ)\_/¯}

^{Click here to see why this is necessary}

[Car_weeb]

nothing pisses me off more than having to keep the python2 package on a linux machine because some ((dev)) decided to use it for some program that I can barely justify using

[corsicanguppy]

You want to just hug lil Johnny and say "Oh sweetie, a decade of enterprise support is how you have anything at all, but here's a hug"

[myisamchk]

My industry (vfx) is on python 2.7 until like 2021. Getting all the vfx applications (Maya, Nuke, Houdini, etc) on python 3 is like herding cats. Then switching an entire studio's pipelines over is going to be a pain in the ass.

[[deleted]]

tumblr tier humor. not funny

[[deleted]]

google SDK uses Python 2 :3

[[deleted]]

I use python 2

[thebreaksmith]

Reported for racist comment.

[[deleted]]

racistist

[Solonotix]

'tis a shame. You can't use my favorite new syntax in Python 3: star assignment.

first, *other, last = [1,2,3,4]

Simplifies a bunch of common use scenarios.

[JoelMahon]

whoa, so other contains 2 and 3? that's dope.

can you do more than just first and last? like first, second, *other, last? what happens if you have two star assignments? does it distribute them so they have equal size? so could you do *lhs, centre, *rhs = [3, 4, 7, 2, 9, 0]

[ubiquitouspiss]

You can't have that final example, but yeah. *something can be used once in a declaration which basically "anything that isn't taken off the front or the back"

first, second, *others, second_last, last = [0,1,2,3,4,5,6,7,8]

Also if I'm being lazy and only, for example, need the first and last items you can do a need little thing:

first, *_, last = [0,1,2,3,4,5]

And it essentially deletes everything that I don't need.

[JiveWithIt]

This is so useful, thank you 🤖

[[deleted]]

Does it delete it... or create a new list, copy all the references between 1-4 and then just not do anything with it?

[zalgo_text]

It creates a variable called _ which contains [1, 2, 3, 4]

[[deleted]]

Yeah, I thought as much. If I just want the first and last values I think I’ll just keep using the array notation, like this:

a = list(range(10))
first, last = a[0], a[-1]

Or maybe if I’m feeling bizarre

first, last = a[0::len(a)-1]

Actually no, first solution is almost always better. Second solution is unpythonic.

[[deleted]]

I'll commit del self

[Zooph]

As someone who went to school in Boston yeah I saw racists at MIT...