TST: Update unreliable num precision component of test_binary_arith_ops (GH37328)
- [x] closes #37328 
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

Seems like a numerical precision issue indeed.

Comparing the values: 16.964677878827604 and 16.964677878827608 I get the following tolerance levels:
Max absolute difference: 3.55271368e-15
Max relative difference: 2.09418281e-16

Therefore I changed: `tm.assert_numpy_array_equal(result.values, expected)` to `tm.assert_almost_equal(result.values, expected, atol=1e-14, rtol=1e-15)` I see that this issue is not limited to those values, I also get this error on #36838, where there's a mismatch between 0.8129387113107932 and 0.8129387113107933

The proposed change would catch it, but maybe we will need to relax the tolerances more to make it generic.  @avinashpancham Merging master should fix the linting error xref #13339 which changed the first assert in `check_binary_arith_op` to `assert_almost_equal`. Make sense we would need to do the same here. @rhshadrach sorry but I dont understand what you mean. Could you maybe give some more explanation? @dsaxton thanks that solved it indeed > @rhshadrach sorry but I dont understand what you mean. Could you maybe give some more explanation?

Now that I read it again it looks more like a general comment, instead of feedback. My bad. CI failed due to: `RuntimeError: can't start new thread`. Would it be possible for someone to restart the CI? > CI failed due to: `RuntimeError: can't start new thread`. Would it be possible for someone to restart the CI?

restarted. cc @jbrockmendel this seems reasonble to me. @jreback merged master and CI is greenish. Errors are memory/OS errors unrelated to this change, do we want to run this again or is this fine? thanks @avinashpancham 