Add coordinate attrs back in for the interp based methods

Author: BSchilperoort

src/xarray_regrid/methods/conservative.py

@@ -77,8 +77,8 @@ def conservative_regrid_dataset(
     latitude_coord: str,
 ) -> xr.Dataset:
     """Dataset implementation of the conservative regridding method."""
-    data_vars: list[str] = list(data.data_vars)
-    data_coords: list[str] = list(data.coords)
+    data_vars = list(data.data_vars)
+    data_coords = list(data.coords)
     dataarrays = [data[var] for var in data_vars]
 
     attrs = data.attrs
@@ -122,7 +122,7 @@ def conservative_regrid_dataarray(
     latitude_coord: str,
 ) -> xr.DataArray:
     """DataArray implementation of the conservative regridding method."""
-    data_coords: list[str] = list(data.coords)
+    data_coords = list(data.coords)
 
     attrs = data.attrs
     coord_attrs = [data[coord].attrs for coord in data_coords]

src/xarray_regrid/methods/interp.py

@@ -39,8 +39,15 @@ def interp_regrid(
     """
     coord_names = set(target_ds.coords).intersection(set(data.coords))
     coords = {name: target_ds[name] for name in coord_names}
+    coord_attrs = {coord: data[coord].attrs for coord in coord_names}
 
-    return data.interp(
+    interped = data.interp(
         coords=coords,
         method=method,
     )
+
+    # xarray's interp drops some of the coordinate's attributes (e.g. long_name)
+    for coord in coord_names:
+        interped[coord].attrs = coord_attrs[coord]
+
+    return interped