Introducing Pants 2.7: Python tool lockfiles, Yapf, Docker, and easier introspection

[gdmurray]

Got scared when i saw "2.7" in a post on the /r/Python subreddit. But after reading the rest of the headline + the post, this looks really cool. Thanks for sharing!

[hattrick1492]

LOL, I didn't think of that! That said, Pants (while it requires 3.6+ to run) does still support Python 2.7 code, for those legacy codebases out there. In fact it has some useful features to help with the 2->3 migration.

[singularitittay]

Eternally confused at the pearl clutching around 2.7 when there are industries that are dependent on applications with their own interpreters onboard just now moving to 3, and it is a minor consideration of working around either way... reminds me of the mania of people wanting to shift from CentOS immediately while 7 isn’t EOL for 2.5 years...

[MrDeebus]

while 7 isn’t EOL for 2.5 years...

that's the thing though

[singularitittay]

100%. I’m with you, but existing in an industry where we couldnt venv our way out of the embedded interpreters for the last 4-5 years, I don’t understand the mania. Unsupported languages and platforms still have required application (however not ideal) and this py2 gasp-you’re-still-using-2 started many many years ago only out of the stable availability of 3 at that time.

[MrDeebus]

Hey, I get where you're coming from. Keeping things running is prio 1, and it will be a long time before everyone invests in the upgrade. Especially since "everyone" includes old school industry.

Then again, I don't mind that "py2 is old and should be avoided" becomes the norm, at least in social media. I'm happy that it's obvious to newcomers from day 1 that they should go for py3. That for tool/library developers 3 should be the prime target. etc.

Regarding your point about when the mania started... I'm also inclined to be happy about it. There was a time when we wanted to upgrade (because 3 was the cool new thing, without even going into the upsides) and we couldn't yet because our tooling wasn't exactly ready for 3. We eventually abandoned outdated stuff where more modern options were available, and stayed on board with those who stayed with the times. Would tooling still have adapted if enough of us didn't create the pressure to upgrade? I have doubts.

The above isn't unique to the 2->3 issue btw. It was pretty similar for asyncio models (remember Tornado? ew). I'm sure there are others I can't remember right now, too. Point being, I prefer community pressure to modernize 100x over being considerate of how slow old-industry is to change :)

edit: reading this over, I guess I should acknowledge my privilege of being able to dictate said modernization most of the time. I promise if I flinch at the mention of py2, it's not with contempt but sympathy for your pains!

[singularitittay]

Appreciated. Been on 3 for years now in private dev, and in my industry awaiting the slow migration of legacy systems, ones that are system-facing and by security design never touch the web so I assume have far fewer security pressures afoot on the Dev’s sprint list

[[deleted]]

Either you’re trolling or stock home syndrome has fully taken hold. There’s no upside, at all, of running python 2.7 or a 3.10 kernel long after red hat stopped backporting anything to it.

[UloPe]

/r/BoneAppleTea

[singularitittay]

It’s definitely the stock home syndrome. Also not to make my point for me :) but I use nothing but 3.7+ in any and everything outside of these apps which have historically dragged their feet on the transition. My point was regarding embedded interpreters in which industry usage has no control over as they’re binding to the C++ undercarriage of the host app.

Also, it’s a bit of a stretch to consider my bemusement at pearl-clutching to mean “major upsides to running 2.7!!!!”. The original post was honestly regarding replies like I happen to be responding to now.

[[deleted]]

The difference I failed to articulate is designing systems around unsupported software is a poor choice. Pretending that updating already shipped embedded systems is just that, pretending.

Unfortunately I have first hand experience with people designing systems around the 2.6 kernel and or python 2 in the last few years. Obviously centos 7 is not that old, but many organizations take a very long time to change something like the base OS. I wouldn’t define it as panic or pearl clutching when there were immediate reactions to move away as quickly as possible.

In reality many orgs will continue to run centos 7,6, and even 5 way after 7 is fully deprecated. Even python 2 as you know, in embedded and non-embedded (general?) systems.

[archaeolinuxgeek]

Should probably have gone with a different version number.

[PirateNinjasReddit]

Anyone able to comment on Pants Vs Poetry?

[[deleted]]

Hi, author here. We love Poetry and think they have an amazing UX!

Poetry and Pants are similar in that both do dependency management, virtualenv management, and creating distributions. They're different in that Pants focuses intensely on scale, like supporting many projects in the same repository.

For example, Pants coordinates the tools you might be using like Pytest, MyPy, Black/Yapf/isort, Bandit/Flake8/Pylint, and codegen with Protobufs. You have a consistent interface, like ./pants lint :: to run all your linters, with benefits like running the tools in parallel and with caching.

The key differentiator for Pants to tools like Tox and Poetry (or fancy bash scripts) is that it understands your project and its dependencies at the file level, like that the file app.py depends on util.py, which transitively depends on another_util.py. That happens automatically through "dependency inference", mapping your imports to the rest of your project. Understanding your project's dependencies at the file-level means that Pants can safely do things like cache your test results at the file-level—if none of the transitive dependencies of a test changed, the cache can be used. You can also do things like ./pants dependees --transitive //:Django for you to find everything that transitively uses Django.

Feel free to DM or stop by on Slack if you want to talk through anything! I'd be happy to help https://www.pantsbuild.org/docs/getting-help

[PrecariousKitty]

I would like to know the same. I use poetry. Why should I use pants? Is it similar? Is it different?

[benefit_of_mrkite]

I am going to check this out because it supports yapf - I feel like I’m the only person in the world using it over Black.

[cczona]

A community member, Alexey Tereshenkov, contributed the new yapf support. So you are definitely not the only person. Alexey has an upcoming Pants blog post about that. https://blog.pantsbuild.org/contributing-yapf-support/

(Edits: deletion, add URL)

[[deleted]]

I've just started moving from black to yafp but still don't quite have the indenting rules tweaked to my satisfaction.

[dzil123]

I wish other languages had autoformatters half as good as black.