AttributeError: module 'numpy' has no attribute 'NAN'. Did you mean: 'nan'?

[aekiss]

When running cice_from_mom to fix COSIMA/access-om3#252 I get

+ cice_from_mom --ocean_hgrid ocean_hgrid.nc --ocean_mask ocean_mask.nc
Traceback (most recent call last):
  File "/g/data/tm70/aek156/domain-tools/C-grid-workflow/fill_fraction_0.5_AK/.venv/bin/cice_from_mom", line 8, in <module>
    sys.exit(cice_from_mom())
  File "/g/data/tm70/aek156/domain-tools/C-grid-workflow/fill_fraction_0.5_AK/.venv/lib/python3.10/site-packages/esmgrids/cli.py", line 42, in cice_from_mom
    mom = MomGrid.fromfile(ocean_hgrid, mask_file=ocean_mask)
  File "/g/data/tm70/aek156/domain-tools/C-grid-workflow/fill_fraction_0.5_AK/.venv/lib/python3.10/site-packages/esmgrids/mom_grid.py", line 106, in fromfile
    clat_t, clon_t, clat_u, clon_u, _, _ = make_corners(x, y)
  File "/g/data/tm70/aek156/domain-tools/C-grid-workflow/fill_fraction_0.5_AK/.venv/lib/python3.10/site-packages/esmgrids/mom_grid.py", line 176, in make_corners
    clon_t[:] = np.NAN
  File "/g/data/tm70/aek156/domain-tools/C-grid-workflow/fill_fraction_0.5_AK/.venv/lib/python3.10/site-packages/numpy/__init__.py", line 414, in __getattr__
    raise AttributeError("module {!r} has no attribute "
AttributeError: module 'numpy' has no attribute 'NAN'. Did you mean: 'nan'?

see esmgrids/mom_grid.py#L176.

Is np.NAN an alias of np.nan that's only available in some versions of numpy? ie should we use np.nan throughout the code instead?

[anton-seaice]

hmm - thats odd. Do you have permissions to trigger the tests manually ? e.g. at https://github.com/COSIMA/esmgrids/actions/workflows/ci.yml ?

[minghangli-uni]

I've never used np.NAN before. Not sure how it might have worked previously.

[anton-seaice]

It looks like np.NAN was deprecated with numpy 2.0 (released mid 2024).

Specifying "numpy ==1.26.4" in pyproject.toml works as expected, and is maybe safer option than updated the esmgrids code in haste.

[aekiss]

changing np.NAN to np.nan throughout the code fixed my issue and is a more future-proof solution if np.NAN is equivalent to np.nan in numpy <2.0

[anton-seaice]

Yeah good - I just wasn't sure if their could be other unexpected differences with numpy 2 !

[aekiss]

I'll open a PR

[anton-seaice]

This was closed through #23

We decided to revert to numpy 1 as the ocean_model_grid_generator test dependency also didn't work with numpy 2. I raised an issue on that repo see ACCESS-NRI/ocean_model_grid_generator#2