Disallow untyped calls in mypy check

[zundertj]

Fixes mypy "disallow_untyped_calls" in #4044 .

[zundertj]

Similar issue as in #4052 with numpy. The Python 3.7 CI run installs numpy 1.21.6, as numpy 1.22 and beyond drop Python 3.7 support (https://numpy.org/devdocs/release/1.22.0-notes.html). This means that there is no way to satisfy type annotations on older numpy, which is not fully type annotated and therefore triggers mypy's no-untyped-call, and at the same time also not use typing.cast or type ignore to satisfy the Python 3.10 run. So we have to make a choice here, do we want to please mypy on all possible Python versions we support, or are we happy to target the latest version(s) only? Not arguing for dropping Python 3.7 altogether, it seems it is from a testing perspective and the ability to use future imports, to not be material.

[codecov-commenter]

Codecov Report

Merging #4053 (c6f0c8e) into master (bc1a498) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #4053   +/-   ##
=======================================
  Coverage   62.89%   62.89%           
=======================================
  Files         451      451           
  Lines       74585    74585           
=======================================
+ Hits        46908    46911    +3     
+ Misses      27677    27674    -3     

Impacted Files	Coverage Δ
py-polars/polars/internals/series.py	94.71% <100.00%> (ø)
polars/polars-io/src/csv/read_impl.rs	79.17% <0.00%> (-2.89%)	⬇️
...s/polars-core/src/chunked_array/upstream_traits.rs	64.92% <0.00%> (-0.87%)	⬇️
polars/polars-core/src/frame/asof_join/groups.rs	77.47% <0.00%> (-0.18%)	⬇️
polars/polars-core/src/series/mod.rs	53.48% <0.00%> (+0.15%)	⬆️
polars/polars-core/src/chunked_array/mod.rs	55.18% <0.00%> (+0.19%)	⬆️
...lars/polars-core/src/series/arithmetic/borrowed.rs	35.77% <0.00%> (+0.20%)	⬆️
polars/polars-arrow/src/kernels/take.rs	70.37% <0.00%> (+0.24%)	⬆️
...lars/polars-core/src/chunked_array/ops/take/mod.rs	51.49% <0.00%> (+0.33%)	⬆️
polars/polars-core/src/utils/mod.rs	52.77% <0.00%> (+0.35%)	⬆️
... and 5 more

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[stinodego]

Hm, tough one. I think we want to keep mypy on Python 3.7 in our CI; I'll do some checks.

Maybe we can merge these changes, but keep the flag disabled until we come up with a solution?

[stinodego]

Nice solution to override the mypy flag in the CI 👍 if the CI is happy, we can merge this.

(CI checks are broken now though, it seems 😄 )

[zundertj]

It is not ideal though. The real issue is the numpy version, rather than the Python version, so this does not work for anyone that develops with numpy < 1.22, even if at Python 3.10. I don't think this will bite much in practice, but my apologies in advance for anyone's time lost due to this little hack.

[stinodego]

The Python test CI checks are still not running, it seems.

[zundertj]

Tried to fix again, but it seems I am hitting this: https://github.community/t/matrix-cannot-be-used-in-jobs-level-if/17177/12. I.e., this is not possible, as the if-statement is evaluated before the matrix. The only solution I see now is to not use the matrix anymore, and thus duplicate the job effectively for Python 3.7.

Open for anyone (with more GH Actions experience) to suggest a better solution.

[ritchie46]

Thanks @zundertj and @stinodego. Merging it in.

[ritchie46]

I had to revert this one because the github action yaml was invalid. We need to run the action if the action file has changed, I shall open an issue for this.

@zundertj can you reopen the PR?

[zundertj]

Cannot re-open, see #4099.