allow custom criteria for name of DataArray (#379)

* allow custom coords name for DataArray

* add whatsnew

* Update cf_xarray/accessor.py

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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Co-authored-by: Deepak Cherian <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: 3 people

cf_xarray/accessor.py

@@ -214,7 +214,11 @@ def _get_custom_criteria(
                 if re.match(patterns, obj[var].attrs.get(criterion, "")):
                     results.update((var,))
                 # also check name specifically since not in attributes
-                elif criterion == "name" and re.match(patterns, var):
+                elif (
+                    criterion == "name"
+                    and isinstance(var, str)
+                    and re.match(patterns, var)
+                ):
                     results.update((var,))
     return list(results)
 

cf_xarray/tests/test_accessor.py

@@ -1498,6 +1498,10 @@ def test_custom_criteria():
     ds["salinity"] = ("dim", np.arange(10))
     assert_identical(ds.cf["salt"], ds["salinity"])
 
+    # match by name of coords for DataArray (#378)
+    da = xr.DataArray([0, 1], coords={"salinity": [2, 3]})
+    assert_identical(da.cf["salt"], da["salinity"])
+
     # Match by standard_name regex match
     ds = xr.Dataset()
     ds["elev"] = ("dim", np.arange(10), {"standard_name": "sea_surface_elevBLAH"})

doc/whats-new.rst

@@ -6,7 +6,7 @@ What's New
 v0.7.6 (unreleased)
 ===================
 
-
+- Allow custom criteria to match the variable name of DataArray objects (:pr:`379`). By `Mathias Hauser`_
 
 v0.7.5 (Nov 15, 2022)
 =====================
@@ -190,4 +190,5 @@ v0.1.3
 .. _`Lars Buntemeyer`: https://github.com/larsbuntemeyer
 .. _`Luke Davis`: https://github.com/lukelbd
 .. _`Martin Schupfner`: https://github.com/sol1105
+.. _`Mathias Hauser`: https://github.com/mathause
 .. _`flag variables`: http://cfconventions.org/Data/cf-conventions/cf-conventions-1.8/cf-conventions.html#flags