CLN: Remove Series._from_array

pandas/core/frame.py

@@ -2166,8 +2166,7 @@ def _ixs(self, i, axis=0):
 
                 if index_len and not len(values):
                     values = np.array([np.nan] * index_len, dtype=object)
-                result = self._constructor_sliced._from_array(
-                    values, index=self.index, name=label, fastpath=True)
+                result = self._box_col_values(values, label)
 
                 # this is a cached value, mark it so
                 result._set_as_cached(label, self)
@@ -2563,8 +2562,16 @@ def _box_item_values(self, key, values):
 
     def _box_col_values(self, values, items):
         """ provide boxed values for a column """
-        return self._constructor_sliced._from_array(values, index=self.index,
-                                                    name=items, fastpath=True)
+        # This check here was previously performed in Series._from_array
+        # By doing it here there is no need for that function anymore
+        # GH#19883.
+        from pandas.core.dtypes.generic import ABCSparseArray
+        this_constructor_sliced = self._constructor_sliced
+        if isinstance(values, ABCSparseArray):
+            from pandas.core.sparse.series import SparseSeries
+            this_constructor_sliced = SparseSeries
+        return this_constructor_sliced(values, index=self.index,
+                                       name=items, fastpath=True)
 
     def __setitem__(self, key, value):
         key = com._apply_if_callable(key, self)

pandas/core/series.py

@@ -305,25 +305,11 @@ def from_array(cls, arr, index=None, name=None, dtype=None, copy=False,
         warnings.warn("'from_array' is deprecated and will be removed in a "
                       "future version. Please use the pd.Series(..) "
                       "constructor instead.", FutureWarning, stacklevel=2)
-        return cls._from_array(arr, index=index, name=name, dtype=dtype,
-                               copy=copy, fastpath=fastpath)
-
-    @classmethod
-    def _from_array(cls, arr, index=None, name=None, dtype=None, copy=False,
-                    fastpath=False):
-        """
-        Internal method used in DataFrame.__setitem__/__getitem__.
-        Difference with Series(..) is that this method checks if a sparse
-        array is passed.
-
-        """
-        # return a sparse series here
         if isinstance(arr, ABCSparseArray):
             from pandas.core.sparse.series import SparseSeries
             cls = SparseSeries
-
-        return cls(arr, index=index, name=name, dtype=dtype, copy=copy,
-                   fastpath=fastpath)
+        return cls(arr, index=index, name=name, dtype=dtype,
+                   copy=copy, fastpath=fastpath)
 
     @property
     def _constructor(self):

pandas/core/sparse/series.py

@@ -216,12 +216,6 @@ def from_array(cls, arr, index=None, name=None, copy=False,
         warnings.warn("'from_array' is deprecated and will be removed in a "
                       "future version. Please use the pd.SparseSeries(..) "
                       "constructor instead.", FutureWarning, stacklevel=2)
-        return cls._from_array(arr, index=index, name=name, copy=copy,
-                               fill_value=fill_value, fastpath=fastpath)
-
-    @classmethod
-    def _from_array(cls, arr, index=None, name=None, copy=False,
-                    fill_value=None, fastpath=False):
         return cls(arr, index=index, name=name, copy=copy,
                    fill_value=fill_value, fastpath=fastpath)
 

pandas/tests/frame/test_subclass.py

@@ -570,3 +570,56 @@ def strech(row):
         result = df.apply(lambda x: [1, 2, 3], axis=1)
         assert not isinstance(result, tm.SubclassedDataFrame)
         tm.assert_series_equal(result, expected)
+
+    def test_frame_subclassing_and_inherit(self):
+        # Subclass frame and series and ensure that data can be transfered
+        # between them on slicing GH#19883
+
+        class CustomSeries(Series):
+
+            def __init__(self, *args, **kw):
+                super(CustomSeries, self).__init__(*args, **kw)
+                self.extra_data = None
+
+            @property
+            def _constructor(self):
+                return CustomSeries
+
+            def __finalize__(self, other, method=None, **kwargs):
+                if method == "_inherit":
+                    self.extra_data = other.extra_data
+                return self
+
+        class CustomDataFrame(DataFrame):
+            """
+            Subclasses pandas DF, fills DF with simulation results, adds some
+            custom temporal data.
+            """
+
+            def __init__(self, *args, **kw):
+                super(CustomDataFrame, self).__init__(*args, **kw)
+                self.extra_data = None
+
+            @property
+            def _constructor(self):
+                return CustomDataFrame
+
+            @property
+            def _constructor_sliced(self):
+                def f(*args, **kwargs):
+                    return CustomSeries(*args, **kwargs).__finalize__(
+                        self, method='_inherit')
+                return f
+
+        data = {'col1': range(10),
+                'col2': range(10)}
+        cdf = CustomDataFrame(data)
+        cdf.extra_data = range(3)
+
+        # column
+        cdf_series = cdf.col1
+        assert cdf_series.extra_data == cdf.extra_data
+
+        # row
+        cdf_series = cdf.iloc[0]
+        assert cdf_series.extra_data == cdf.extra_data