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Python 2 will be replaced with Python 3 in the next RHEL major release

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Re: Python 2 will be replaced with Python 3 in the next RHEL major release

#221

Post by asdfk »

toyg wrote: post #135
sametmax wrote: post #124

Earlier quoted context omitted.

s/security/bug I don't think that centos 6 is bug free yet it EOL in 2010 too. Actually i'm using it right now and I'm positive it has at least one bug when running in virtualbox. My client won't upgrade. They pay support, expensive support, to keep their old version. In 2020 I'll open a shop to convert old Python code bases or fix bugs in them. I'll charge 4 times market rate. For me it's a net win that people don't…

Sometimes I wonder if the opensource movement, with its perennial “update anxiety”, is actually busy generating an industry of legacy maintenance. In a way, it’s a natural extension of the original “development is free but you pay for support” idea, but I don’t think anyone openly elaborated it into a long-term revenue-generating strategy. It looks like a slam-dunk, to be honest, with the only caveat being that work…

the old trick is to get your changes to the main branch so you dont need to maintain your it. that is also why anyone bothers to do so in the first place

Re: Python 2 will be replaced with Python 3 in the next RHEL major release

#222

Post by bitL »

Avshalom wrote: post #206
bitL wrote: post #107

Earlier quoted context omitted.

You forgot one: - 90% of business code is written in Python 2.x

yeah and 90% of business code is also written in COBOL and another 90% in MUMPS, but somehow the world continues to work despite the fact that they've been pining for the fjords for decades.

There is obviously a massive jump from COBOL to Python, and small but annoyingly incompatible step from Python 2 to Python 3. I hope you understand the difference. It's not like Python 3 was the best language ever, it's just a variation (and IMO not that great one to justify breaking backwards compatibility) of the same theme. Ask Perl guys how they liked a similar situation.

If I didn't need to use Python, I wouldn't. Now why I have to rewrite my old code to v3 if it works? Why do I have to waste time with such a stupid thing? All my new code is v3, but why is somebody nagging me about v3 all the time when v3 is full of warts and mindblowing conceptual holes as well, and doesn't really address multi-threading (GIL love forever) etc.? Coming from C++/Java to Python world it was like throwing away a lot of powerful stuff in exchange for faster time to write. Didn't expect that would be dragged down by additional time to rewrite because of some half-baked API-breaking changes.

Re: Python 2 will be replaced with Python 3 in the next RHEL major release

#223

Post by montecarl »

exabrial wrote: post #217

As someone completely ignorant in everything python... can someone explain why Python 3 has never replaced Python 2?

Part of it is that Python 3 does not offer any really strong reasons to switch to it, in an existing code base. It is definitely better and rounds out a bunch of small problems and inconsistencies that exist in Python 2. It also does have some cool new features. However, since Python 3 is not compatible with Python 2 (there is very good tooling for automatic converting and supporting both in one code base) many developers have not taken the time to port their code.

Re: Python 2 will be replaced with Python 3 in the next RHEL major release

#224

Post by dodobirdlord »

exabrial wrote: post #217

As someone completely ignorant in everything python... can someone explain why Python 3 has never replaced Python 2?

Python 3 broke backwards compatibility with Python 2. Most of the usefulness of Python comes from the fact that you can import modules. Since all of the existing modules had been written in Python 2 and would not work with Python 3, most people ignored the release of Python 3 and continued using Python 2.

Re: Python 2 will be replaced with Python 3 in the next RHEL major release

#226

Post by Something1234 »

bastawhiz wrote: post #212
hartator wrote: post #203

Earlier quoted context omitted.

> Well, the CGI industry had money, competent people, and 10 years to upgrade. An entire decade. And a LOT of tooling and documentation to help. I don’t think that’s a money issue. Python 3 upgrade is not really compelling. You get slower speed - at least until recently -, tests might pass on 3.x, but documentation and edge cases still are better on 2.x, etc. While nothing is really exciting in the 3.x branch.

>While nothing is really exciting in the 3.x branch. Sorry, have you looked at Python 3 lately? I don't think I can sum up all of the amazing work that's been done in one post (async? Cleaned up stdlib? Better errors? Not having an aneurysm from text encoding issues unraveling your whole project? New splat syntax?). I would really encourage you to check out what's happened in the last ten years. I think you'll find m…

splat == list unpacking

https://stackoverflow.com/questions/2322355/proper-name-for-...

Re: Python 2 will be replaced with Python 3 in the next RHEL major release

#227

Post by minusf »

consp wrote: post #158
bitL wrote: post #107

Earlier quoted context omitted.

You forgot one: - 90% of business code is written in Python 2.x

We've switched from 2.7 to 3.4 (and upwards to 3.5, 3.6) in about a month or so. It delayed some deployments but nothing serious. If you do it step-by-step it's not that hard. The worst part was str/binary conversions but afterwards everything was a lot easier and better to maintain. If your company is big enough you should maintain and keep it up-to-date, not "it just works"(TM) and hope for the best after 10 years.…

even if it's "easy", does not mean it's "simple", or "quick". ever maintained a plone/zope instance? life is too short to convert that to python3 :}

Re: Python 2 will be replaced with Python 3 in the next RHEL major release

#228

Post by compuguy »

dajonker wrote: post #3

This is good: - Python 2 support officially ends somewhere in 2020 - most popular packages are now compatible with Python 3 - Python 3.7 performs about as well as 2.7 with future release expected to be better Although it still took way too long, if you consider Python 3.0 was released about 10 years ago.

Ansible still doesn't support Python 3....

Re: Python 2 will be replaced with Python 3 in the next RHEL major release

#229

Post by Diederich »

icegreentea2 wrote: post #126
raverbashing wrote: post #29

Earlier quoted context omitted.

Got a source for the performance regressions? Some things are faster in Python 3 than 2 "Most popular" packages, which ones? Most moved a long time ago to Python 3

Here's some light benchmarking (this was posted a few weeks ago I think...) https://hackernoon.com/which-is-the-fastest-version-of-pytho... Basically once 3.7 is out (which is soon), CPython3 will finally be broadly faster than CPython2.7. Interpreter startup time is still annoying though. I really wonder what the right strategy for addressing that is. Like honestly 2.7 is faster than 3.x, but 2.7 CLI tools still fee…

> light benchmarking

Thanks for this!

Do you know of any more longer term, less light Py2/3 benchmarking?

Re: Python 2 will be replaced with Python 3 in the next RHEL major release

#230

Post by UncleEntity »

oblio wrote: post #148
dagw wrote: post #127

Earlier quoted context omitted.

the GIL was not removed or at least a solid parallelism story was not included Not for lack of trying. People have been trying to do this since at least python 1.4. They just haven't found a way of doing it without negatively affecting single threaded performance, which Guido considers an unacceptable trade-off. http://pyparallel.org is probably the most interesting latest experiment in this field, but it never got c…

They were breaking many things, maybe they should have rewritten the C API? From what I remember that's the blocker. That would have broken all C extensions, but it's not like Python 3 at launch was a raving success regarding library porting.

They did break all C extensions in py3k -- not so bad you can't work around it with some preprocessor magic but break it they did.

And they continued to break them within the py3k lifetime, mostly unicode related stuff from what I can remember. Probably still break stuff but I haven't had time for my toy python projects in a while so haven't been messing with the C-API lately.

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