[Freak_NL]

Python 3 is ten (!) years old and perfectly usable, but it suffers from a well-known, but curious problem where people who occasionally use Python for some light scripting tend to go for Python 2.7. Rarely it's a choice made because of library availability, more often it is because of the perceived ubiquity of Python 2.7 installs on the target user's computer or simply because of a mindset where Python 2.7 is good enough and getting the hang of Python 3 seems like a huge obstacle (it isn't).

I'd love to know why this project specifically chose Python 2.7 too. Python 2 reaches its end of life in 2020, any new Python code should really be written in Python 3.

By the way, if you want to prevent getting a bunch of downvotes like your comment did, be polite! Not including any capitalization or punctuation is considered downright rude by many. Your text reads like a robot's printout.

[j1elo]

It's not a huge obstacle, but it _is_ an obstacle.

I'm not a Python programmer, but I can find my way around without much issue. Still, from where I'm sitting all that stuff about envs and the 2, 3 or 4 redundant, overriden, or deprecated mix of solutions sounds strange to me, I don't really want to buy into that just yet (I need Python like once per month, no more). For the casual programmer ("just want to change this line and run, please") it's just a block in the road that virtually all instructions you might see on any random README in Github might tell you to use "pip install..." but then you have to second guess if they mean "pip2" or "pip3", and whether they assume you'll be running with v2 or v3, maybe they tell you to run "pip install something" (which runs pip2), then in the script there is a Python 3 shebang... the installed dependency won't be found and now you have to understand all this mess if you want to continue.

This is in Ubuntu, where the system's "python" is Python 2, and you need to explicitly add a "3" to all your commands if you want to run v3. I'm sure there are clever ways to solve the issue, but I bet they'll break some use case. I'd just rather none of this nonsense existed at all, then no funny workarounds would be needed.

I wonder, how come other languages are able to slowly introduce some breaking changes over time (I'd swear Ruby was mentioned in some other HN thread about doing this) but not cause this kind of mess (as perceived from my humble external point of view)?

[dev_dull]

In other words, most likely because it’s the default python interpreter for this system.

[josefx]

You forgot one reason not to switch from 2 to 3: Zero benefit. Nothing python 3 does would benefit my scripts to any extend over just using python 2 as I always did. Is learning 3 a huge hurdle? No, it is however in some cases completely unnecessary.

[shawnz]

The benefit is that you won't be stunting adoption of Python 3, which will help get us back to a homogeneous Python landscape more quickly.

[jake_the_third]

Seeing that there was a vulnerability in python just a couple days ago, I'd consider getting security updates a benefit.

Most people will stop running python 2 when malware targeting it becomes rampant. So people being able to run your code is another benefit.

:o)

[rdtsc]

Great point. Python 3 for many just wasn't a great carrot. That's why they didn't switch. For a while it was even slower. Also most importantly Python 2 wasn't that bad of a stick. It was just pretty darn good to begin with. And of course that it is still supported on some OS-s people will keep using.

[rjeli]

Yeah, for writing scripts like this - python 2: 0% chance of thinking about Unicode. python 3: 5% chance i have to waste time debugging some random str decoding issue, no benefits. why bother?

[shawnz]

This might be true if you're an english speaker, running the script on an english platform and only consuming data from english services. And also you are sure that no non-english speaker will ever take over the development of your script and you will never have to localize it to other languages. Otherwise, it's exactly the opposite. Python 3 is what you should be using if you want 0% chance of being stopped by a string encoding issue.

Python 3 might occasionally require some extra steps when consuming strings compared to Python 2, but the reality is that those steps were always necessary. Python 2 just hid those details in a way that was only really safe for english-exclusive development. That doesn't mean that Python 2 is easier to use or less brittle. In fact I would say it means the opposite.

[josefx]

For most strings I don't care about language, encoding or related overhead. In my scripts they are best dealt with as ophaque bytes with a few specific byte patterns that are the same in ascii and utf8, as well as various other encodings.

Last unicode issue I had was on a system german characters, because some library assumed it had to explicitly perform encoding with a bad default setting. If the library didn't try to be smart the program would have worked independently of system or language, instead it failed on any non english system by trying to convert a perfectly fine, system specific encoding to utf8.

[_0w8t]

Python2 worked fine with Russian input/output.

[hackbinary]

Why bother? Because Python 2 is EOL in a little less than 2 years.

The NHS chose not to upgrade to from Windows XP and 2003 and look where that got them last year: a massive crypto locker infection.

[rphlx]

FWIW Win10 was affected by that same horrific SMB RCE vuln. So the implied argument that 10 has been immune or even much less vulnerable to ransomware over the past year or two is on shaky ground, though I agree it probably will start to have some merit going forward.

[rwmj]

I suppose unless someone either forks it or keeps delivering patches outside the Python project. That wasn't really an option for Windows XP, but I'm quite sure if it had been then someone would be doing it.

[sweettea]

This is already true -- tauthon is a updated, patched Python 2 fork. https://github.com/naftaliharris/tauthon

[cmyr]

Put another way: python 2 has a 0% chance of correctly handling Unicode.

[mjevans]

Not actually the case. UTF-8, using only SPECIFIC operations that don't try to split up strings or replace things that aren't exact matches for a given text, will result in valid output as long as there was valid input.

All interchanged Unicode text should be UTF-8, never use another encoding* (without a really compelling reason).

No, storing it as an array of unicode characters isn't a compelling reason during interchange.

ALSO, never use a BOM; that will break things.

The second answer (should be anchor-linked) in this goes over MOST of the advantages of UTF-8, but it doesn't capture that some carefully input operations in otherwise completely Unicode //unaware// 'string' functions result in no change to string validity.

The only potential issue is if recognizing something in different normalization representations is important. However, for nearly all quick and dirty tasks (where a short script is most likely) it usually doesn't matter. For everything else a different paradigm than the one Python3 picked would be better. (One where adding filters to a read file is OPTIONAL and they can be invoked on individual byte-strings as well.)

https://stackoverflow.com/questions/6882301/what-is-the-best...

[baq]

You must live in the US.

[odonnellryan]

You don't have to learn Python 3, and there are plenty of cool features (ok well being cool isn't always enough reason but it is a reason) and there are libraries that are not supported on 2.x anymore.

Also you don't have so much longer until support drops entirely for 2.x, and then you really should port your projects. Why wait and port? Just write them in 3.

There is nothing wrong with 3. Just starting in 3 is easy and not an issue. It is basically the same language.

[carapace]

This. I've been trying to make this point myself but people don't seem to want to acknowledge it, so it's gratifying to hear someone else say it too.

What if Python 3 was a separate project that someone other than GvR had put forward, would adoption have the same impetus? I don't think so.

[avian]

> I'd love to know why this project specifically chose Python 2.7 too.

My guess is they just went with whatever was most convenient and worked. I doubt if this kind of questions were even on the radar. It's security research, not a production website. In research you tend to go with whatever tool does the job.

Look at the overall complexity of this work. Maybe the author simply felt more confident with Python 2. You take whatever shortcuts that make things simpler, even if it means using 20 year old software.

[gaius]

more often it is because of the perceived ubiquity of Python 2.7 installs on the target user's computer

It’s not just “perceived”, it is actual reality e.g. on CentOS. If you need compatibility still the best option is 2, regardless.

[ptx]

In RHEL 8, Python 3 is finally the default Python version: https://developers.redhat.com/blog/2018/11/14/python-in-rhel...

[Wowfunhappy]

^^ Python 2.7 is also available by default on macOS, whereas you have to go out of your way to install Python 3.

[gaius]

... and Debian 9

I’m no Luddite but the simple fact today if you want to reliably deploy and can’t or don’t want to ship a container, Python 2 is the reality.

[rphlx]

FWIW deb9 installs both 3.5 and 2.7 by default.

[_0w8t]

On Redhat and compatible systems python 2 will be supported for at least 10 years.

[dijit]

30th of June 2024 is not 10 years away. RHEL 7 will be the last RedHat with python2 by default and it goes end of life in 2024.

Additionally; expecting them to properly support all the new features and manually creating (not backporting) fixes for issues is accrediting RedHat with having more resources than the reality allows.

[_0w8t]

EOL for RHEL 8 will be in 10 years and python2 in RHEL8 will be a fully supported package even if not installed by default. And I suspect that it is not only Redhat that will need to support python2 past 2020. For example, I guess Ubuntu 20.4 with EOL in 2025 will still have a package. So there will be upgrade and fixes for python2 just not from python.org.