I had a discussion on IRC with Brian yesterday which led to the question whether we can drop support for Python 3.5. I think there are good reasons for this, see the rationale below.
Brian proposed to initiate a vote on this topic (and find out whether this "community thing" works :-) ). Please send feedback by Friday Sept 14th. Especially, let me know if there are specific reasons for depending on Python 3.5. The corresponding issue is 3984 [7]. Cheers, Simon Rationale: The trigger for the discussion was to get rid of boilerplate code like this [0], [1] to handle batches in the stages API. This becomes a single line [2] when using an asynchronous generator [3]. Adding the `batches()` async generator to Pulp core would simplify existing stages and ease implementation of stages in plugins. Async generators have been introduced in Python 3.6. Thus, to make the `batches` generator available in the Pulp core plugin API, we either - have to drop support for Python 3.5 or - reimplement the async generator as an async iterator (which would be more convoluted but looks doable) I prefer to drop 3.5, since this will allow to use additional language features[4]. Among them: - As said, async generators/async comprehensions. Async generators are simpler to write and understand than async iterators. - String interpolation "f-Strings" [5] - dict objects preserve insertion-order (officially declared part of the language with Python 3.7). Eliminates a source of subtle "works on 3.6, sometimes works on 3.5" bugs. - One version less to support is always a good thing (provided nobody really requires it) - Type annotations are currently not used by the Pulp project, but if the project decides to use them in the future: IMHO type annotations (which are great btw.) began to feel ârightâ with 3.6. Working with them in 3.5 can be clumsy at times. - And of course: [6] Python 3.6 has the OS/distribution support we need: - Python 3.6 SCL is available for RHEL 7 / CentOS 7 - It is part of Fedora as of Fedora 26 For Ubuntu, it is part of 18.04 LTS. Debian does not have Python 3.6 in stable yet. [0] https://github.com/pulp/pulp/blob/631031e38270c5c7c2b2289ff4ab87a058447c5e/plugin/pulpcore/plugin/stages/content_unit_stages.py#L47-L59 [1] https://github.com/pulp/pulp/blob/631031e38270c5c7c2b2289ff4ab87a058447c5e/plugin/pulpcore/plugin/stages/artifact_stages.py#L48-L60 [2] https://github.com/gmbnomis/pulp_cookbook/blob/ca4882cecab16995c5713d27131da8112a5f5a0c/pulp_cookbook/app/tasks/synchronizing.py#L98 [3] https://github.com/gmbnomis/pulp_cookbook/blob/d44ed593925b78c046e1b568810b15acbdad5ac4/pulp_cookbook/app/tasks/synchronizing.py#L26 [4] https://docs.python.org/3/whatsnew/3.6.html [5] https://docs.python.org/3/whatsnew/3.6.html#pep-498-formatted-string-literals [6] https://twitter.com/raymondh/status/844955415259463681 [7] https://pulp.plan.io/issues/3984 _______________________________________________ Pulp-dev mailing list Pulp-dev@redhat.com https://www.redhat.com/mailman/listinfo/pulp-dev