As was previously mentioned in yt 4.0.0's release notes, we're currently

planning to drop support for Python 3.6 in our next feature release (4.1.0)

I propose that this change be performed on the dev branch of yt by late

October this year, but not earlier than October the 20th.

As was discussed on Slack, I would like to send an official announcement

to yt-users@python.org, but I’ll leave open to discussion for a week first, or

as long as necessary for the discussion to resolve happily.

Please take minute to either request changes, discuss and/or approve it.

Nice implications

This means we'll soon be able to use Python 3.7+ only syntax and features.

Here are the two key highlights that I personally think are most impactful for yt:

`from __future__ import annotations` can be used to leverage modern Python annotations features from more recent versions (as late as 3.11 !) This will be extremely useful to improve typing in yt, and in support to YTEP 0038 https://github.com/yt-project/ytep/pull/17 Here's a gist with some showcase examples of how this __future__ import helps simplifying typed code https://gist.github.com/neutrinoceros/0eaa046a00689254dee0738c65c9bdfc
the `dataclasses` module becomes available https://docs.python.org/3/whatsnew/3.7.html#whatsnew37-pep557

See the detailed "what's new" note from Python 3.7.0 for more https://docs.python.org/3/whatsnew/3.7.html

Additional notes

Python 3.6 is 5 years old and will be EOL (end of life) by December https://www.python.org/dev/peps/pep-0494/
Numpy dropped support for Python 3.6 in numpy 1.20.0, released in January 2021 https://github.com/numpy/numpy/releases/tag/v1.20.0
Matplotlib dropped support fot Python 3.6 in matplotlib 3.4.0, released in March 2021 https://github.com/matplotlib/matplotlib/commit/f9907b49f9d00c03cf014a25d057d0d09d43d8cf
Python 3.10 will be officially released early October https://www.python.org/dev/peps/pep-0619/
Adding support for 3.10 should be a breeze^{TM}: we've been running a subset of our test suite against it (+ future versions of matplotlib and numpy) for a couple months, so the expected most important bottleneck for us will depend on when numpy and matplotlib are able to publish wheels for 3.10
The plan is to first add support to 3.10 and *then* drop 3.6.
This is in agreement with NEP 29, which was coauthored by our own release manager, Madicken Munk https://numpy.org/neps/nep-0029-deprecation_policy.html
Various 3.7+ idioms will now be continuously enforced with pyupgrade https://github.com/asottile/pyupgrade which is already part of our pre-commit toolbelt.

Cheers, and have a great week