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. 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/ - 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. >
