Keep the original ordering of the coordinates

ci/requirements/py36-min-nep18.yml

@@ -10,7 +10,7 @@ dependencies:
   - distributed=2.9
   - numpy=1.17
   - pandas=0.25
-  - pint=0.13
+  - pint=0.15
   - pip
   - pytest
   - pytest-cov

xarray/core/concat.py

@@ -349,7 +349,11 @@ def _parse_datasets(
         all_coord_names.update(ds.coords)
         data_vars.update(ds.data_vars)
 
-        for dim in set(ds.dims) - dims:
+        # preserves ordering of dimensions
+        for dim in ds.dims:
+            if dim in dims:
+                continue
+
             if dim not in dim_coords:
                 dim_coords[dim] = ds.coords[dim].variable
         dims = dims | set(ds.dims)

xarray/core/dataset.py

@@ -1123,7 +1123,13 @@ def _copy_listed(self, names: Iterable[Hashable]) -> "Dataset":
         coord_names = set()
         indexes: Dict[Hashable, pd.Index] = {}
 
-        for name in names:
+        def key(name):
+            try:
+                return list(self._variables.keys()).index(name)
+            except ValueError:
+                return len(self._variables)
+
+        for name in sorted(names, key=key):
             try:
                 variables[name] = self._variables[name]
             except KeyError:
@@ -1142,7 +1148,11 @@ def _copy_listed(self, names: Iterable[Hashable]) -> "Dataset":
 
         dims = {k: self.dims[k] for k in needed_dims}
 
-        for k in self._coord_names:
+        # preserves ordering of coordinates
+        for k in self._variables:
+            if k not in self._coord_names:
+                continue
+
             if set(self.variables[k].dims) <= needed_dims:
                 variables[k] = self._variables[k]
                 coord_names.add(k)
@@ -5729,10 +5739,10 @@ def filter_by_attrs(self, **kwargs):
         <xarray.Dataset>
         Dimensions:         (time: 3, x: 2, y: 2)
         Coordinates:
-            reference_time  datetime64[ns] 2014-09-05
+            lon             (x, y) float64 -99.83 -99.32 -99.79 -99.23
             lat             (x, y) float64 42.25 42.21 42.63 42.59
           * time            (time) datetime64[ns] 2014-09-06 2014-09-07 2014-09-08
-            lon             (x, y) float64 -99.83 -99.32 -99.79 -99.23
+            reference_time  datetime64[ns] 2014-09-05
         Dimensions without coordinates: x, y
         Data variables:
             precipitation   (x, y, time) float64 5.68 9.256 0.7104 ... 7.992 4.615 7.805
@@ -5742,10 +5752,10 @@ def filter_by_attrs(self, **kwargs):
         <xarray.Dataset>
         Dimensions:         (time: 3, x: 2, y: 2)
         Coordinates:
-            reference_time  datetime64[ns] 2014-09-05
+            lon             (x, y) float64 -99.83 -99.32 -99.79 -99.23
             lat             (x, y) float64 42.25 42.21 42.63 42.59
           * time            (time) datetime64[ns] 2014-09-06 2014-09-07 2014-09-08
-            lon             (x, y) float64 -99.83 -99.32 -99.79 -99.23
+            reference_time  datetime64[ns] 2014-09-05
         Dimensions without coordinates: x, y
         Data variables:
             temperature     (x, y, time) float64 29.11 18.2 22.83 ... 18.28 16.15 26.63

xarray/tests/test_testing.py

@@ -70,12 +70,7 @@ def test_assert_allclose(obj1, obj2):
         pytest.param(
             quantity,
             id="pint",
-            marks=[
-                pytest.mark.skipif(not has_pint, reason="requires pint"),
-                pytest.mark.xfail(
-                    reason="inconsistencies in the return value of pint's implementation of eq"
-                ),
-            ],
+            marks=pytest.mark.skipif(not has_pint, reason="requires pint"),
         ),
     ),
 )
@@ -115,12 +110,7 @@ def test_assert_duckarray_equal_failing(duckarray, obj1, obj2):
         pytest.param(
             quantity,
             id="pint",
-            marks=[
-                pytest.mark.skipif(not has_pint, reason="requires pint"),
-                pytest.mark.xfail(
-                    reason="inconsistencies in the return value of pint's implementation of eq"
-                ),
-            ],
+            marks=pytest.mark.skipif(not has_pint, reason="requires pint"),
         ),
     ),
 )