bounds attrs are not dropped for dropped variables

[veenstrajelmer]

Bounds attrs are not dropped when linked variables are dropped upon merging. For instance, when merging the grevelingen mapfiles, the variables 'mesh2d_face_x_bnd' and 'mesh2d_face_y_bnd' since they cannot be aligned. However, the variables mesh2d_face_x and mesh2d_face_y have bounds attrs that are not dropped. When writing this to a file, we therefore end up with references to variables that are not available anymore.

MWE:

import dfm_tools as dfmt
uds = dfmt.data.fm_grevelingen_map()
print(uds.mesh2d_face_x.attrs)

Prints: {'units': 'm', 'standard_name': 'projection_x_coordinate', 'long_name': 'Characteristic x-coordinate of mesh face', 'mesh': 'mesh2d', 'location': 'face', 'bounds': 'mesh2d_face_x_bnd'}

[mgeraeds]

Adding on this, manually removing the bounds from the attributes does not seem to work; they will not be dropped, even with del uds['mesh2d_face_x'].attrs['bounds']. I only got it to work when first writing from an xu.UgridDataset to an xr.Dataset and then dropping the variables (through writing new attrs or using del on the 'bounds' attr).

[veenstrajelmer]

@mgeraeds you are referring to a quickplot crash when opening such a dataset. This happened only with a very old quickplot version (from 2018). With version 2.65.140745 (13-Feb-2022) and also higher versions, the missing bounds variables give a warning, but there is no crash and QuickPlot functions normally. It should still be solved eventually, but manually dropping the bounds attrs seems not necessary.