> Separately, I am curious what the precise symptoms of dropping Python 2.7 support will be. I admit I haven't been able to follow all the threads on the topic. Is it moving on to newer dependencies, or also wanting to use new language features, or something more subtle?
Once we remove Py2 support we will update python_requires stanza[1], so new Apache Beam release artifacts will not be installable on Python 2. We will remove Py2 test suites and will gradually cleanup parts in the codebase where we branch to make sure the code can run both on Py2 and Py3 (random example: [2]). > Is it moving on to newer dependencies, We will reduce the risk of not being able to upgrade to new dependencies and chances of other dependencies breaking us[3] as they drop Py2 support. > or also wanting to use new language features, or something more subtle? Once we are no longer required to support Python 2, Beam developers will be able to use Python 3 language features and common standard library features without backports. With Python 3.5 reaching EOL in September we can expect Python 3.6 to become our next lowest common denominator. [1] https://github.com/apache/beam/blob/956e4eb39a7fedbae05985c759284557dcc3d9ec/sdks/python/setup.py#L261 [2] https://github.com/apache/beam/blob/956e4eb39a7fedbae05985c759284557dcc3d9ec/sdks/python/apache_beam/runners/worker/operations.py#L936 [3] https://lists.apache.org/thread.html/rbac6e3b5c5629b756945640c5b0432a32dd76b3e5b261a1420bbc4a0%40%3Cdev.beam.apache.org%3E On Fri, Jul 24, 2020 at 3:41 PM Kenneth Knowles <k...@apache.org> wrote: > Regardless of the outcome, it would be good to have some more details > here. Can you share links for people to find out more about Python 3 > support in those products and their timeline? I did some quick searching > out of curiosity but I do not believe I found the authoritative information. > > Separately, I am curious what the precise symptoms of dropping Python 2.7 > support will be. I admit I haven't been able to follow all the threads on > the topic. Is it moving on to newer dependencies, or also wanting to use > new language features, or something more subtle? > > Kenn > > On Thu, Jun 18, 2020 at 5:01 PM Chad Dombrova <chad...@gmail.com> wrote: > >> Hi all, >> Sorry I've been AWOL. I've been pulled in a number of different >> directions. >> >> We are still increasing our use of Beam, and I have it on my todo list to >> reach out to Kenneth about how Beam could be expanded into the VFX / >> Animation industries. >> >> Our industry uses a number of specialized applications with embedded >> python interpreters. We run Beam inside these interpreters, so we're >> waiting for them to switch to python3. >> >> Here's the status report for python3 adoption in our key applications: >> >> *Maya*: In Beta >> *Houdini*: Released >> *Nuke*: In Beta >> *Katana*: Not started (Alpha?) >> >> I hate to be the one holding the project back, and I understand if you >> all ultimately decide it's untenable to wait any longer. The good news is >> 3 out of 4 applications should be ready in the next 2-3 months. I can do >> some investigation into what workarounds might look like for Katana, or >> maybe we can use the Beta version once python3 support arrives, which would >> move our schedule forward. >> >> When would 2.24 release? >> >> -chad >> >> >> >> >> >> >> >> >> >> On Thu, Jun 18, 2020 at 4:33 PM Ahmet Altay <al...@google.com> wrote: >> >>> OK, tweeted the message. Could you share on Slack? >>> >>> On Thu, Jun 18, 2020 at 4:28 PM Valentyn Tymofieiev <valen...@google.com> >>> wrote: >>> >>>> Alright, let's publish the message on Twitter and echo on Slack once >>>> that's done. >>>> Thank you! >>>> >>>> On Tue, Jun 16, 2020 at 5:31 PM Ahmet Altay <al...@google.com> wrote: >>>> >>>>> That sounds reasonable to me. I agree, it is better to get specific >>>>> reasons rather than a yes/no answer. >>>>> >>>>> On Tue, Jun 16, 2020 at 1:50 PM Valentyn Tymofieiev < >>>>> valen...@google.com> wrote: >>>>> >>>>>> After thinking about it for a bit, I am not sure whether a poll would >>>>>> be actionable. For example, if 1000 users provide a positive response >>>>>> and 5 >>>>>> users provide a negative response, how do we interpret that and where do >>>>>> we draw a line? How about instead we encourage users to reach out, and >>>>>> tell >>>>>> what is not working for them? For example: >>>>>> >>>>>> Beam is considering making 2.23.0 a final release supporting Py2. If >>>>>> you are not able to switch to Python 3, please let us know why: [short >>>>>> link >>>>>> to user@ thread] [1]. >>>>>> >>>>>> Thoughts? >>>>>> >>>>>> [1] >>>>>> https://lists.apache.org/thread.html/r0de71d98d98b213dd1d0c45c1f5642135116f25def5637a5f41c8d29%40%3Cuser.beam.apache.org%3E >>>>>> >>>>>> On Tue, Jun 16, 2020 at 11:50 AM Ahmet Altay <al...@google.com> >>>>>> wrote: >>>>>> >>>>>>> >>>>>>> >>>>>>> On Tue, Jun 16, 2020 at 11:38 AM Valentyn Tymofieiev < >>>>>>> valen...@google.com> wrote: >>>>>>> >>>>>>>> I have reached out to user@ for feedback on Python 3 migration[1]. >>>>>>>> >>>>>>> >>>>>>> Maybe also ask on slack? There are quite a bit of users there as >>>>>>> well. >>>>>>> >>>>>>> >>>>>>>> >>>>>>>> Could somebody from PMC please help with Twitter poll? >>>>>>>> >>>>>>> >>>>>>> I can try to do this. What question would you like to ask? I do not >>>>>>> know much about twitter polls but I assume they have character limits >>>>>>> similar to regular tweets. >>>>>>> >>>>>>> >>>>>>>> >>>>>>>> Technically, we can proceed with the change between 2.23.0 and >>>>>>>> 2.24.0, so that's after 2.23.0 is cut and we give sufficient time for >>>>>>>> users >>>>>>>> to respond. >>>>>>>> >>>>>>>> [1] >>>>>>>> https://lists.apache.org/thread.html/r0de71d98d98b213dd1d0c45c1f5642135116f25def5637a5f41c8d29%40%3Cuser.beam.apache.org%3E >>>>>>>> On Tue, Jun 16, 2020 at 9:22 AM Ismaël Mejía <ieme...@gmail.com> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> Yes we need to poll this outside as Robert proposed. >>>>>>>>> >>>>>>>>> The proposed last support version corresponds with the next >>>>>>>>> release that will be >>>>>>>>> cut in two weeks. Sounds a bit short if we count the time to poll >>>>>>>>> people on this >>>>>>>>> subject but still could be. >>>>>>>> >>>>>>>> Technically, we can proceed with the change between 2.23.0 and >>>>>>>> 2.24.0, so that's after 2.23.0 is cut and we give sufficient time for >>>>>>>> users >>>>>>>> to respond. >>>>>>>> >>>>>>>> >>>>>>>>> I remember Chad mentioned in this thread the impossibility to get >>>>>>>>> support for >>>>>>>>> python 2 in his industry until the end of the year, Maybe things >>>>>>>>> have improved. >>>>>>>>> Have they? >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> On Tue, Jun 16, 2020 at 6:10 PM Robert Bradshaw < >>>>>>>>> rober...@google.com> wrote: >>>>>>>>> > >>>>>>>>> > I like that option as a concrete proposal. I think we should >>>>>>>>> circulate it more widely (the users list, twitter poll, at least a new >>>>>>>>> thread...), maybe phrasing it as "is there any reason you couldn't >>>>>>>>> migrate >>>>>>>>> to Python 3 (or stick with an older version of Beam) after 2.23 (due >>>>>>>>> to be >>>>>>>>> cut here in a couple of weeks)?" If there is strong concern/pushback, >>>>>>>>> we >>>>>>>>> could consider holding on for one more release. >>>>>>>>> > >>>>>>>>> > On Tue, Jun 16, 2020 at 8:54 AM David Cavazos < >>>>>>>>> dcava...@google.com> wrote: >>>>>>>>> >> >>>>>>>>> >> +1 >>>>>>>>> >> >>>>>>>>> >> On Mon, Jun 15, 2020 at 6:52 PM Udi Meiri <eh...@google.com> >>>>>>>>> wrote: >>>>>>>>> >>> >>>>>>>>> >>> +1 >>>>>>>>> >>> >>>>>>>>> >>> On Mon, Jun 15, 2020 at 4:27 PM Ahmet Altay <al...@google.com> >>>>>>>>> wrote: >>>>>>>>> >>>> >>>>>>>>> >>>> As a concrete proposal, could we commit to removing python 2 >>>>>>>>> support by 2.24? In other words, mark the next release 2.23 as the >>>>>>>>> last >>>>>>>>> python 2 compatible Beam version. >>>>>>>>> >>>> >>>>>>>>> >>>> On Mon, Jun 15, 2020 at 2:09 PM Valentyn Tymofieiev < >>>>>>>>> valen...@google.com> wrote: >>>>>>>>> >>>>> >>>>>>>>> >>>>> Another input here: >>>>>>>>> >>>>> >>>>>>>>> >>>>> If you opened a Python PR in the last few days, you probably >>>>>>>>> noticed that our test suites were broken by a transitive dependency >>>>>>>>> of Beam >>>>>>>>> that dropped python 2 support, but did not declare python_requires>=3 >>>>>>>>> in >>>>>>>>> its setup.py [1]. This temporarily broke a subset of Beam Py2 users >>>>>>>>> (who >>>>>>>>> did not explicitly pin the 'rsa' dependency), and still affects Beam >>>>>>>>> development[2]. >>>>>>>>> >>>>> >>>>>>>>> >>>>> This is the second time[3] Beam is affected with an issue of >>>>>>>>> this kind, so support of Python 2 starts to slow down our >>>>>>>>> development, and >>>>>>>>> add toil for maintainers of packages we depend on (both directly and >>>>>>>>> transitively). >>>>>>>>> >>>>> >>>>>>>>> >>>>> [1] https://github.com/sybrenstuvel/python-rsa/issues/152 >>>>>>>>> >>>>> [2] >>>>>>>>> https://lists.apache.org/thread.html/r9993b40b0c1cb8682ce56013165d4b80fdde0ee469a73bcb9466ddfb%40%3Cdev.beam.apache.org%3E >>>>>>>>> >>>>> [3] https://github.com/hamcrest/PyHamcrest/issues/131 >>>>>>>>> >>>>> >>>>>>>>> >>>>> On Tue, Jun 9, 2020 at 4:06 PM Ahmet Altay <al...@google.com> >>>>>>>>> wrote: >>>>>>>>> >>>>>> >>>>>>>>> >>>>>> Thank you for re-opening this Valentyn. I am in favor of >>>>>>>>> EOLing py2 support sooner than later. The reality is that we will not >>>>>>>>> be >>>>>>>>> effectively supporting beam python 2 for a long time while the >>>>>>>>> ecosystem >>>>>>>>> already EOLed python 2. That said, a significant chunk (but no longer >>>>>>>>> a >>>>>>>>> majority) of our users are still using python 2. Upgrades are >>>>>>>>> painful, it >>>>>>>>> might be especially painful nowadays. It would be good to hear >>>>>>>>> counter view >>>>>>>>> points, user voices related to this. >>>>>>>>> >>>>>> >>>>>>>>> >>>>>> On Thu, Jun 4, 2020 at 4:53 PM Valentyn Tymofieiev < >>>>>>>>> valen...@google.com> wrote: >>>>>>>>> >>>>>>> >>>>>>>>> >>>>>>> Back at the end of February we decided to revisit this >>>>>>>>> conversation in 3 months. Do folks on this thread have any new input >>>>>>>>> or >>>>>>>>> perspective regarding us balancing "user pain/contributor pain/our >>>>>>>>> ability >>>>>>>>> to continuously test with python 2 in a shifting environment"? >>>>>>>>> >>>>>>> >>>>>>>>> >>>>>>> Some new information on my end is that we have been seeing >>>>>>>>> steady adoption of Python 3 among Beam Python users in Dataflow, >>>>>>>>> particularly strong adoption among streaming users, and Dataflow is >>>>>>>>> sunsetting Python 2 support for all released Beam SDKs later this >>>>>>>>> year [1]. >>>>>>>>> We will have to remove Python 2 Beam test suites that use Dataflow >>>>>>>>> when >>>>>>>>> Dataflow runner disables Py2 support if this happens before Beam Py2 >>>>>>>>> EOL >>>>>>>>> (when we have to remove all Py2 suites), including performance tests >>>>>>>>> that >>>>>>>>> still use Dataflow on Python 3. >>>>>>>>> >>>>>>> >>>>>>>>> >>>>>>> I am curious how much motivation there is in the community >>>>>>>>> at this moment to continue Py2 support in Beam, whether any previous >>>>>>>>> Py3 >>>>>>>>> migration blockers were resolved or any new blockers discovered among >>>>>>>>> Beam >>>>>>>>> users. >>>>>>>>> >>>>>>> >>>>>>>>> >>>>>>> [1] >>>>>>>>> https://cloud.google.com/python/docs/python2-sunset/#dataflow >>>>>>>>> >>>>>>> >>>>>>>>> >>>>>>> On Fri, May 8, 2020 at 3:52 PM Valentyn Tymofieiev < >>>>>>>>> valen...@google.com> wrote: >>>>>>>>> >>>>>>>> >>>>>>>>> >>>>>>>> That's good news! Thanks for sharing. >>>>>>>>> >>>>>>>> >>>>>>>>> >>>>>>>> Another datapoint, here are a few of Beam's dependencies >>>>>>>>> that no longer release new py2 artifacts (I looked at >>>>>>>>> REQUIRED_PACKAGES + >>>>>>>>> aws, gcp, and interactive extras): >>>>>>>>> >>>>>>>> >>>>>>>>> >>>>>>>> hdfs >>>>>>>>> >>>>>>>> numpy >>>>>>>>> >>>>>>>> pyarrow >>>>>>>>> >>>>>>>> ipython >>>>>>>>> >>>>>>>> >>>>>>>>> >>>>>>>> There are more if we include transitive dependencies and >>>>>>>>> test-only packages. I also remember encountering one issue last month >>>>>>>>> that >>>>>>>>> was broken only on Py2, which we had to go back and fix. >>>>>>>>> >>>>>>>> >>>>>>>>> >>>>>>>> If others have noticed frictions related to ongoing Py2 >>>>>>>>> support or have updates on previously mentioned Py3 migration >>>>>>>>> blockers, >>>>>>>>> feel free to post them. >>>>>>>>> >>>>>>>> >>>>>>>>> >>>>>>>> On Fri, May 8, 2020 at 9:19 AM Robert Bradshaw < >>>>>>>>> rober...@google.com> wrote: >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> It hasn't been 3 months yet, but I wanted to call out a >>>>>>>>> milestone that >>>>>>>>> >>>>>>>>> Python 3 downloads crossed the 50% threshold on pypi, if >>>>>>>>> just briefly. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> On Thu, Feb 13, 2020 at 12:40 AM Ismaël Mejía < >>>>>>>>> ieme...@gmail.com> wrote: >>>>>>>>> >>>>>>>>> > >>>>>>>>> >>>>>>>>> > > I would suggest re-evaluating this within the next 3 >>>>>>>>> months again. We need to balance between user pain/contributor >>>>>>>>> pain/our >>>>>>>>> ability to continuously test with python 2 in a shifting environment. >>>>>>>>> >>>>>>>>> > >>>>>>>>> >>>>>>>>> > Good idea for the in 3 months evaluation, at that >>>>>>>>> point also distributions will probably be phasing out python2 by >>>>>>>>> default >>>>>>>>> which definitely help in this direction. >>>>>>>>> >>>>>>>>> > Thanks for updating the roadmap Ahmet >>>>>>>>> >>>>>>>>> > >>>>>>>>> >>>>>>>>> > >>>>>>>>> >>>>>>>>> > On Thu, Feb 13, 2020 at 2:49 AM Ahmet Altay < >>>>>>>>> al...@google.com> wrote: >>>>>>>>> >>>>>>>>> >> >>>>>>>>> >>>>>>>>> >> >>>>>>>>> >>>>>>>>> >> >>>>>>>>> >>>>>>>>> >> On Wed, Feb 12, 2020 at 1:29 AM Ismaël Mejía < >>>>>>>>> ieme...@gmail.com> wrote: >>>>>>>>> >>>>>>>>> >>> >>>>>>>>> >>>>>>>>> >>> I am with Chad on this, we should probably extend it >>>>>>>>> a bit more, even if it >>>>>>>>> >>>>>>>>> >>> makes us struggle a bit at least we have some >>>>>>>>> workarounds as Robert suggests, >>>>>>>>> >>>>>>>>> >>> and as Chad said there are still many people playing >>>>>>>>> the python 3 catchup game, >>>>>>>>> >>>>>>>>> >>> so worth to support those users. >>>>>>>>> >>>>>>>>> >>> >>>>>>>>> >>>>>>>>> >>> >>>>>>>>> >>>>>>>>> >>> But maybe it is worth to evaluate the current state >>>>>>>>> later in the year. >>>>>>>>> >>>>>>>>> >> >>>>>>>>> >>>>>>>>> >> >>>>>>>>> >>>>>>>>> >> I would suggest re-evaluating this within the next 3 >>>>>>>>> months again. We need to balance between user pain/contributor >>>>>>>>> pain/our >>>>>>>>> ability to continuously test with python 2 in a shifting environment. >>>>>>>>> >>>>>>>>> >> >>>>>>>>> >>>>>>>>> >>> >>>>>>>>> >>>>>>>>> >>> In the >>>>>>>>> >>>>>>>>> >>> meantime can someone please update our Roadmap in >>>>>>>>> the website with this info and >>>>>>>>> >>>>>>>>> >>> where we are with Python 3 support (it looks not up >>>>>>>>> to date). >>>>>>>>> >>>>>>>>> >>> https://beam.apache.org/roadmap/ >>>>>>>>> >>>>>>>>> >> >>>>>>>>> >>>>>>>>> >> >>>>>>>>> >>>>>>>>> >> I made a minor change to update that page ( >>>>>>>>> https://github.com/apache/beam/pull/10848). A more comprehensive >>>>>>>>> update to that page and linked ( >>>>>>>>> https://beam.apache.org/roadmap/python-sdk/#python-3-support) >>>>>>>>> would still be welcome. >>>>>>>>> >>>>>>>>> >> >>>>>>>>> >>>>>>>>> >>> >>>>>>>>> >>>>>>>>> >>> >>>>>>>>> >>>>>>>>> >>> - Ismaël >>>>>>>>> >>>>>>>>> >>> >>>>>>>>> >>>>>>>>> >>> >>>>>>>>> >>>>>>>>> >>> On Tue, Feb 4, 2020 at 10:49 PM Robert Bradshaw < >>>>>>>>> rober...@google.com> wrote: >>>>>>>>> >>>>>>>>> >>>> >>>>>>>>> >>>>>>>>> >>>> On Tue, Feb 4, 2020 at 12:12 PM Chad Dombrova < >>>>>>>>> chad...@gmail.com> wrote: >>>>>>>>> >>>>>>>>> >>>> >> >>>>>>>>> >>>>>>>>> >>>> >> Not to mention that all the nice work for the >>>>>>>>> type hints will have to be redone in the for 3.x. >>>>>>>>> >>>>>>>>> >>>> > >>>>>>>>> >>>>>>>>> >>>> > Note that there's a tool for automatically >>>>>>>>> converting type comments to annotations: >>>>>>>>> https://github.com/ilevkivskyi/com2ann >>>>>>>>> >>>>>>>>> >>>> > >>>>>>>>> >>>>>>>>> >>>> > So don't let that part bother you. >>>>>>>>> >>>>>>>>> >>>> >>>>>>>>> >>>>>>>>> >>>> +1, I wouldn't worry about what can be easily >>>>>>>>> automated. >>>>>>>>> >>>>>>>>> >>>> >>>>>>>>> >>>>>>>>> >>>> > I'm curious what other features you'd like to be >>>>>>>>> using in the Beam source that you cannot now. >>>>>>>>> >>>>>>>>> >>>> >>>>>>>>> >>>>>>>>> >>>> I hit things occasionally, e.g. I just ran into >>>>>>>>> wanting keyword-only >>>>>>>>> >>>>>>>>> >>>> arguments the other day. >>>>>>>>> >>>>>>>>> >>>> >>>>>>>>> >>>>>>>>> >>>> >> It seems the faster we drop support the better. >>>>>>>>> >>>>>>>>> >>>> > >>>>>>>>> >>>>>>>>> >>>> > >>>>>>>>> >>>>>>>>> >>>> > I've already gone over my position on this, but a >>>>>>>>> refresher for those who care: some of the key vendors that support my >>>>>>>>> industry will not offer python3-compatible versions of their software >>>>>>>>> until >>>>>>>>> the 4th quarter of 2020. If Beam switches to python3-only before that >>>>>>>>> point we may be forced to stop contributing features (note: I'm the >>>>>>>>> guy who >>>>>>>>> added the type hints :). Every month you can give us would be >>>>>>>>> greatly >>>>>>>>> appreciated. >>>>>>>>> >>>>>>>>> >>>> >>>>>>>>> >>>>>>>>> >>>> As another data point, we're still 80/20 on Py2/Py3 >>>>>>>>> for downloads at >>>>>>>>> >>>>>>>>> >>>> PyPi [1] (which I've heard should be taken with a >>>>>>>>> grain of salt, but >>>>>>>>> >>>>>>>>> >>>> likely isn't totally off). IMHO that ratio needs to >>>>>>>>> be way higher for >>>>>>>>> >>>>>>>>> >>>> Python 3 to consider dropping Python 2. It's pretty >>>>>>>>> noisy, but say it >>>>>>>>> >>>>>>>>> >>>> doubles every 3 months that would put us at least >>>>>>>>> mid-year before we >>>>>>>>> >>>>>>>>> >>>> hit a cross-over point. On the other hand Q4 2020 >>>>>>>>> is probably a >>>>>>>>> >>>>>>>>> >>>> stretch. >>>>>>>>> >>>>>>>>> >>>> >>>>>>>>> >>>>>>>>> >>>> We could consider whether it needs to be an >>>>>>>>> all-or-nothing thing as >>>>>>>>> >>>>>>>>> >>>> well. E.g. perhaps some features could be Python 3 >>>>>>>>> only sooner than >>>>>>>>> >>>>>>>>> >>>> the whole codebase. (This would have to be well >>>>>>>>> justified.) Another >>>>>>>>> >>>>>>>>> >>>> mitigation is that it is possible to mix Python 2 >>>>>>>>> and Python 3 in the >>>>>>>>> >>>>>>>>> >>>> same pipeline with portability, so if there's a >>>>>>>>> library that you need >>>>>>>>> >>>>>>>>> >>>> for one DoFn it doesn't mean you have to hold back >>>>>>>>> your whole >>>>>>>>> >>>>>>>>> >>>> pipeline. >>>>>>>>> >>>>>>>>> >>>> >>>>>>>>> >>>>>>>>> >>>> - Robert >>>>>>>>> >>>>>>>>> >>>> >>>>>>>>> >>>>>>>>> >>>> [1] https://pypistats.org/packages/apache-beam , >>>>>>>>> and that 20% may just >>>>>>>>> >>>>>>>>> >>>> be a spike. >>>>>>>>> >>>>>>>>
