Bring back python 3.9 in the integration tests

[sergisiso]

python3.9 is not EOLd yet and Archer2 which has LFRic users defaults to it. So it would be good to test against it.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.92%. Comparing base (af5cb94) to head (bc07a25).
Report is 7 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #3043   +/-   ##
=======================================
  Coverage   99.92%   99.92%           
=======================================
  Files         366      366           
  Lines       51721    51721           
=======================================
+ Hits        51680    51681    +1     
+ Misses         41       40    -1     

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[sergisiso]

@LonelyCat124 This is ready for review. I am bringing back python 3.9 as EPCC and other people from NG-Arch are using it on Archer2. I am tempted to suggest that we update the previous changelog instead of creating a new issue for this as it was only a couple of PRs ago and the issue didn't specify 3.9.

[LonelyCat124]

Hi @sergisiso - I'll review this when I'm back from leave next week - can you set the integration running in the mean time?

[schreiberx]

@sergisiso Thanks. I had some issues with Python 3.9 with the most recent Psyclone version.

[sergisiso]

@arporter @LonelyCat124 Can you give some priority to this. It is very easy to introduce breaking changes if its not tested.

[arporter]

I'll take it now.

[arporter]

All looks fine @sergisiso, thanks for fixing this (and apologies for being too hasty in removing it). Just a request to make a new issue to drop 3.9 when it goes EOL (in October 2025) so that we can put back the commented-out test.

[sergisiso]

@arporter I don't think I agree with the comments, we don't need a TODO for things that will continue to be valid, there are many Optional, Unions through the codebase and I don't think it is a goal to remove those. The commented out assert may be a better location but even then, I don't think we should deprecate 3.9 anytime soon (October), since it is the default on Archer2 and probably means it is the default in similar RedHat/Cray machines.

[arporter]

The commented out assert may be a better location but even then, I don't think we should deprecate 3.9 anytime soon (October), since it is the default on Archer2 and probably means it is the default in similar RedHat/Cray machines.

Good point - we'll probably need 3.9 for longer as you say. In that case, please could you change the test back to something that works for all versions so that we don't have commented-out code.

[LonelyCat124]

@arporter I don't think I agree with the comments, we don't need a TODO for things that will continue to be valid, there are many Optional, Unions through the codebase and I don't think it is a goal to remove those. The commented out assert may be a better location but even then, I don't think we should deprecate 3.9 anytime soon (October), since it is the default on Archer2 and probably means it is the default in similar RedHat/Cray machines.

I think we should have a rule with how we want to do Union or Optional types (at least for in-code type hints) and have the code be consistent, my preference would be the newer a | b or a | None style, but I'm not too bothered either way. The latter requires 3.10 though I think so we can't move to it until then.

[sergisiso]

@arporter Ready for another review

[arporter]

I think we should have a rule with how we want to do Union or Optional types (at least for in-code type hints) and have the code be consistent, my preference would be the newer a | b or a | None style, but I'm not too bothered either way. The latter requires 3.10 though I think so we can't move to it until then.

Me too but yes, it will have to wait. I always forget how slowly HPC platforms evolve.

[arporter]

Thanks Sergi. This can be merged now.