Cleanup uses of super() to use Python 3 only syntax (#3069)

No user facing changes

asv_bench/benchmarks/indexing.py

@@ -122,5 +122,5 @@ def time_assignment_vectorized(self, key):
 class IndexingDask(Indexing):
     def setup(self, key):
         requires_dask()
-        super(IndexingDask, self).setup(key)
+        super().setup(key)
         self.ds = self.ds.chunk({'x': 100, 'y': 50, 't': 50})

asv_bench/benchmarks/interp.py

@@ -50,5 +50,5 @@ def time_interpolation_2d(self, method):
 class InterpolationDask(Interpolation):
     def setup(self, *args, **kwargs):
         requires_dask()
-        super(InterpolationDask, self).setup(**kwargs)
+        super().setup(**kwargs)
         self.ds = self.ds.chunk({'t': 50})

asv_bench/benchmarks/reindexing.py

@@ -40,5 +40,5 @@ def time_2d_fine_some_missing(self):
 class ReindexDask(Reindex):
     def setup(self):
         requires_dask()
-        super(ReindexDask, self).setup()
+        super().setup()
         self.ds = self.ds.chunk({'time': 100})

asv_bench/benchmarks/rolling.py

@@ -63,6 +63,6 @@ def time_rolling_construct(self, center, stride):
 class RollingDask(Rolling):
     def setup(self, *args, **kwargs):
         requires_dask()
-        super(RollingDask, self).setup(**kwargs)
+        super().setup(**kwargs)
         self.ds = self.ds.chunk({'x': 100, 'y': 50, 't': 50})
         self.da_long = self.da_long.chunk({'x': 10000})

asv_bench/benchmarks/unstacking.py

@@ -22,5 +22,5 @@ def time_unstack_slow(self):
 class UnstackingDask(Unstacking):
     def setup(self, *args, **kwargs):
         requires_dask()
-        super(UnstackingDask, self).setup(**kwargs)
+        super().setup(**kwargs)
         self.ds = self.ds.chunk({'flat_dim': 50})

xarray/core/indexing.py

@@ -352,7 +352,7 @@ def __init__(self, key):
                                 .format(type(self).__name__, k))
             new_key.append(k)
 
-        super(BasicIndexer, self).__init__(new_key)
+        super().__init__(new_key)
 
 
 class OuterIndexer(ExplicitIndexer):
@@ -388,7 +388,7 @@ def __init__(self, key):
                                 .format(type(self).__name__, k))
             new_key.append(k)
 
-        super(OuterIndexer, self).__init__(new_key)
+        super().__init__(new_key)
 
 
 class VectorizedIndexer(ExplicitIndexer):
@@ -427,7 +427,7 @@ def __init__(self, key):
                                 .format(type(self).__name__, k))
             new_key.append(k)
 
-        super(VectorizedIndexer, self).__init__(new_key)
+        super().__init__(new_key)
 
 
 class ExplicitlyIndexed:

xarray/core/merge.py

@@ -110,7 +110,7 @@ class OrderedDefaultDict(OrderedDict):
     # beware: does not pickle or copy properly
     def __init__(self, default_factory):
         self.default_factory = default_factory
-        super(OrderedDefaultDict, self).__init__()
+        super().__init__()
 
     def __missing__(self, key):
         self[key] = default = self.default_factory()

xarray/core/resample.py

@@ -163,7 +163,7 @@ def __init__(self, *args, dim=None, resample_dim=None, **kwargs):
         self._dim = dim
         self._resample_dim = resample_dim
 
-        super(DataArrayResample, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
     def apply(self, func, shortcut=False, args=(), **kwargs):
         """Apply a function over each array in the group and concatenate them
@@ -204,7 +204,7 @@ def apply(self, func, shortcut=False, args=(), **kwargs):
         applied : DataArray or DataArray
             The result of splitting, applying and combining this array.
         """
-        combined = super(DataArrayResample, self).apply(
+        combined = super().apply(
             func, shortcut=shortcut, args=args, **kwargs)
 
         # If the aggregation function didn't drop the original resampling
@@ -236,7 +236,7 @@ def __init__(self, *args, dim=None, resample_dim=None, **kwargs):
         self._dim = dim
         self._resample_dim = resample_dim
 
-        super(DatasetResample, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
     def apply(self, func, args=(), shortcut=None, **kwargs):
         """Apply a function over each Dataset in the groups generated for
@@ -301,7 +301,7 @@ def reduce(self, func, dim=None, keep_attrs=None, **kwargs):
         if dim == DEFAULT_DIMS:
             dim = None
 
-        return super(DatasetResample, self).reduce(
+        return super().reduce(
             func, dim, keep_attrs, **kwargs)
 
 

xarray/core/rolling.py

@@ -178,7 +178,7 @@ def __init__(self, obj, windows, min_periods=None, center=False):
         Dataset.rolling
         Dataset.groupby
         """
-        super(DataArrayRolling, self).__init__(
+        super().__init__(
             obj, windows, min_periods=min_periods, center=center)
 
         self.window_labels = self.obj[self.dim]
@@ -401,7 +401,7 @@ def __init__(self, obj, windows, min_periods=None, center=False):
         Dataset.groupby
         DataArray.groupby
         """
-        super(DatasetRolling, self).__init__(obj, windows, min_periods, center)
+        super().__init__(obj, windows, min_periods, center)
         if self.dim not in self.obj.dims:
             raise KeyError(self.dim)
         # Keep each Rolling object as an OrderedDict

xarray/core/variable.py

@@ -1840,8 +1840,7 @@ class IndexVariable(Variable):
     """
 
     def __init__(self, dims, data, attrs=None, encoding=None, fastpath=False):
-        super(IndexVariable, self).__init__(dims, data, attrs, encoding,
-                                            fastpath)
+        super().__init__(dims, data, attrs, encoding, fastpath)
         if self.ndim != 1:
             raise ValueError('%s objects must be 1-dimensional' %
                              type(self).__name__)
@@ -1959,7 +1958,7 @@ def copy(self, deep=True, data=None):
     def equals(self, other, equiv=None):
         # if equiv is specified, super up
         if equiv is not None:
-            return super(IndexVariable, self).equals(other, equiv)
+            return super().equals(other, equiv)
 
         # otherwise use the native index equals, rather than looking at _data
         other = getattr(other, 'variable', other)

xarray/tests/test_backends.py

@@ -1656,7 +1656,7 @@ def test_encoding_kwarg_fixed_width_string(self):
     # makes sense for Zarr backend
     @pytest.mark.xfail(reason="Zarr caching not implemented")
     def test_dataset_caching(self):
-        super(CFEncodedBase, self).test_dataset_caching()
+        super().test_dataset_caching()
 
     def test_append_write(self):
         ds, ds_to_append, _ = create_append_test_data()
@@ -1668,7 +1668,7 @@ def test_append_write(self):
 
     @pytest.mark.xfail(reason="Zarr stores can not be appended to")
     def test_append_overwrite_values(self):
-        super(CFEncodedBase, self).test_append_overwrite_values()
+        super().test_append_overwrite_values()
 
     def test_append_with_invalid_dim_raises(self):
 
@@ -1825,13 +1825,13 @@ def test_append_write(self):
         import scipy
         if scipy.__version__ == '1.0.1':
             pytest.xfail('https://github.com/scipy/scipy/issues/8625')
-        super(ScipyWriteBase, self).test_append_write()
+        super().test_append_write()
 
     def test_append_overwrite_values(self):
         import scipy
         if scipy.__version__ == '1.0.1':
             pytest.xfail('https://github.com/scipy/scipy/issues/8625')
-        super(ScipyWriteBase, self).test_append_overwrite_values()
+        super().test_append_overwrite_values()
 
 
 @requires_scipy

xarray/tests/test_dataset.py

@@ -112,12 +112,11 @@ def create_test_multiindex():
 
 class InaccessibleVariableDataStore(backends.InMemoryDataStore):
     def __init__(self):
-        super(InaccessibleVariableDataStore, self).__init__()
+        super().__init__()
         self._indexvars = set()
 
     def store(self, variables, *args, **kwargs):
-        super(InaccessibleVariableDataStore, self).store(
-            variables, *args, **kwargs)
+        super().store(variables, *args, **kwargs)
         for k, v in variables.items():
             if isinstance(v, IndexVariable):
                 self._indexvars.add(k)

xarray/tests/test_variable.py

@@ -1776,32 +1776,32 @@ class TestVariableWithDask(VariableSubclassobjects):
 
     @pytest.mark.xfail
     def test_0d_object_array_with_list(self):
-        super(TestVariableWithDask, self).test_0d_object_array_with_list()
+        super().test_0d_object_array_with_list()
 
     @pytest.mark.xfail
     def test_array_interface(self):
         # dask array does not have `argsort`
-        super(TestVariableWithDask, self).test_array_interface()
+        super().test_array_interface()
 
     @pytest.mark.xfail
     def test_copy_index(self):
-        super(TestVariableWithDask, self).test_copy_index()
+        super().test_copy_index()
 
     @pytest.mark.xfail
     def test_eq_all_dtypes(self):
-        super(TestVariableWithDask, self).test_eq_all_dtypes()
+        super().test_eq_all_dtypes()
 
     def test_getitem_fancy(self):
-        super(TestVariableWithDask, self).test_getitem_fancy()
+        super().test_getitem_fancy()
 
     def test_getitem_1d_fancy(self):
-        super(TestVariableWithDask, self).test_getitem_1d_fancy()
+        super().test_getitem_1d_fancy()
 
     def test_equals_all_dtypes(self):
         import dask
         if '0.18.2' <= LooseVersion(dask.__version__) < '0.19.1':
             pytest.xfail('https://github.com/pydata/xarray/issues/2318')
-        super(TestVariableWithDask, self).test_equals_all_dtypes()
+        super().test_equals_all_dtypes()
 
     def test_getitem_with_mask_nd_indexer(self):
         import dask.array as da
@@ -1901,31 +1901,31 @@ def test_datetime64(self):
     # IndexVariable objects:
     @pytest.mark.xfail
     def test_getitem_error(self):
-        super(TestIndexVariable, self).test_getitem_error()
+        super().test_getitem_error()
 
     @pytest.mark.xfail
     def test_getitem_advanced(self):
-        super(TestIndexVariable, self).test_getitem_advanced()
+        super().test_getitem_advanced()
 
     @pytest.mark.xfail
     def test_getitem_fancy(self):
-        super(TestIndexVariable, self).test_getitem_fancy()
+        super().test_getitem_fancy()
 
     @pytest.mark.xfail
     def test_getitem_uint(self):
-        super(TestIndexVariable, self).test_getitem_fancy()
+        super().test_getitem_fancy()
 
     @pytest.mark.xfail
     def test_pad(self):
-        super(TestIndexVariable, self).test_rolling_window()
+        super().test_rolling_window()
 
     @pytest.mark.xfail
     def test_rolling_window(self):
-        super(TestIndexVariable, self).test_rolling_window()
+        super().test_rolling_window()
 
     @pytest.mark.xfail
     def test_coarsen_2d(self):
-        super(TestIndexVariable, self).test_coarsen_2d()
+        super().test_coarsen_2d()
 
 
 class TestAsCompatibleData: