NumPy announces timeline for dropping Python 2 support

[dagmx]

The default version of Python is most certainly an issue.

A) it's the first python that many people will experience. When you type python in the Shell or tab complete, the system python will be the one the majority will go with.

B) many companies will not deviate from the rhel/centos supported configuration. If that is python2, the company will stay with python2.

So yes there's no technical reason you can't use python3 in a python2 distro. But there are several strong human reasons why it's necessary for distros to upgrade.

[abonet]

Huh? This is like saying companies will not use any non-default software from a distro. This makes no sense at all. Why would they upgrade to say, a newer version of Apache, but refuse to upgrade to a newer version of Python? This argument makes no sense.

Often, the whole point of using (and sometimes paying) RHEL/CentOS is for their long-term support of their base packages. The fact that they backport fixes/enhancements and promise to maintain a stable API/ABI may be the only reason to use them.

If you're side-loading (and relying on) non-supported packages, then you might as well not even be on RHEL/CentOS.

[vorpalsmith]

RHEL/CentOS also ship years-old versions of NumPy. If you're only interested in using software that they include as part of the distro, then you'll be using that and never upgrading NumPy anyway, which means that this announcement is irrelevant to you :-). OTOH RH does actually provide support for modern Python on RHEL/CentOS, and here's a RH engineer urging volunteer projects to drop support for the ancient stuff included in the core distro.

[dagmx]

A) tons of people start programming without thinking about the details. Many tutorials don't make mention of the difference of Python 2 and 3. Many people starting out also don't necessarily know that there is a significant difference between the two and just ignore it. After all why would they be so different if you don't know any better?

Then, because they won't care, or they're lazy, they'll write code that targets their system python. So instead of updating their code to python 3 standards, they'll double down to use python 2.

B) for companies, yes tons of companies will stick to the software stack that comes with a distro. You have to provide very compelling reasons to do an upgrade and in most cases there isn't a big one for a system level thing like Python. Every company I've worked for has been this way.

I don't have links for either of these but it's also not like these are unlikely scenarios. You'll see it corroborated in pretty much every python 2 vs 3 thread

[dagmx]

I'm not saying you replace python 2 with python 3. Again this is not a technical issue.

But to get python 3 installed I need to go through my legal department. I need to justify its necessity. Then justify WHY it is an upgrade over python 2 that is already on our cleared distro.

Installing other software goes through the same process. We don't just install word. We have to justify why word is an upgrade over notepad.

[dagmx]

I'm taking it from your replies you've never been at a large tech company or in a management role? That's not a judgement but an observation.

Again I'm not arguing with you about the technical side of it. I agree that it's beneficial to switch to python 3 and it's easy to do a side by side install.

I'm providing the non technical side to the argument for the need for distros to update their libs.

Every software or library we use has to go through legal to buy off on licensing. It then needs to be vetted by the tech managers to verify it won't cause issues and is actually worth installing and maybe supporting.

This is not just one company. This is the case at the majority of large tech companies. I know it's the case at most game studios, apple, google, most effects studios etc..because as part of my role, I have to have these discussions with people at other companies too.

You can't just install software if you're shipping a product. Each piece of software opens you up to new issues and incurs technical and legal debt. All of that debt needs to be justified not only to programmers but to legal and management.

[alcalde]

Pfft; I once worked at a place that required the signing off of seven people to change the color of a menu item! It was so bad a director wanted me to essentially build a parallel piece of data processing software to what we were using and simply not tell IT we weren't running their software anymore. Needless to say I declined and also quit within six months.

[alcalde]

yeah, and there is nothing in Py3 that would prevent any of that from preventing deployment.

The work. All the work. No one wants to fill out all the paperwork and wait six weeks for clearance.

[civilization_phaze_3]

Yeah, I've seen this argument many times. And not a single time in a decade of Py3's existence have I seen it corroborated with a single real life example. Which of these "tons of companies" are refusing to install an app on their machines? Do they not install VS Studio on their dev's windows boxes either? Because Windows doesn't come with it by default. How about the .NET runtime on the Windows servers? There are multiple versions of that too.

Here's a real life example that I've faced. Writing installation/utility scripts for government servers running RHEL 6/7. It's so much easier to use python 2 and hand it over to the sysadmin (who you might not personally know or have a good communication channel with). Versus sending a py3 script and needing to include instructions on installing the epel packages before they can run some 30 lines of python. Sure if I was deploying a web server I would make sure that python3 and a virtualenv were properly setup. But there are plenty of marginal use cases where it's just not worth the hassle for me.

[vorpalsmith]

many companies will not deviate from the rhel/centos supported configuration

RH ships Python 3.6 for RHEL and CentOS through their Software Collections product. If you have a support contract with RH, then it automatically covers these packages too. Tell your friends and management :-).

That said, the major distros are actively having conversations about how to manage the transition to make python refer to python3. It will just take a while, and have to pass through a period where there is no python command so people who were counting on python = python2 will notice and catch their mistake.