CLN: deduplicate __setitem__ and _reduce on masked arrays (pandas-dev#34187)

Author: jorisvandenbossche

pandas/core/arrays/boolean.py

@@ -18,16 +18,13 @@
     is_integer_dtype,
     is_list_like,
     is_numeric_dtype,
-    is_scalar,
     pandas_dtype,
 )
 from pandas.core.dtypes.dtypes import register_extension_dtype
 from pandas.core.dtypes.generic import ABCDataFrame, ABCIndexClass, ABCSeries
 from pandas.core.dtypes.missing import isna
 
-from pandas.core import nanops, ops
-from pandas.core.array_algos import masked_reductions
-from pandas.core.indexers import check_array_indexer
+from pandas.core import ops
 
 from .masked import BaseMaskedArray, BaseMaskedDtype
 
@@ -347,19 +344,8 @@ def reconstruct(x):
         else:
             return reconstruct(result)
 
-    def __setitem__(self, key, value) -> None:
-        _is_scalar = is_scalar(value)
-        if _is_scalar:
-            value = [value]
-        value, mask = coerce_to_array(value)
-
-        if _is_scalar:
-            value = value[0]
-            mask = mask[0]
-
-        key = check_array_indexer(self, key)
-        self._data[key] = value
-        self._mask[key] = mask
+    def _coerce_to_array(self, value) -> Tuple[np.ndarray, np.ndarray]:
+        return coerce_to_array(value)
 
     def astype(self, dtype, copy: bool = True) -> ArrayLike:
         """
@@ -670,24 +656,7 @@ def _reduce(self, name: str, skipna: bool = True, **kwargs):
         if name in {"any", "all"}:
             return getattr(self, name)(skipna=skipna, **kwargs)
 
-        data = self._data
-        mask = self._mask
-
-        if name in {"sum", "prod", "min", "max"}:
-            op = getattr(masked_reductions, name)
-            return op(data, mask, skipna=skipna, **kwargs)
-
-        # coerce to a nan-aware float if needed
-        if self._hasna:
-            data = self.to_numpy("float64", na_value=np.nan)
-
-        op = getattr(nanops, "nan" + name)
-        result = op(data, axis=0, skipna=skipna, mask=mask, **kwargs)
-
-        if np.isnan(result):
-            return libmissing.NA
-
-        return result
+        return super()._reduce(name, skipna, **kwargs)
 
     def _maybe_mask_result(self, result, mask, other, op_name: str):
         """

pandas/core/arrays/integer.py

@@ -20,15 +20,13 @@
     is_integer_dtype,
     is_list_like,
     is_object_dtype,
-    is_scalar,
     pandas_dtype,
 )
 from pandas.core.dtypes.dtypes import register_extension_dtype
 from pandas.core.dtypes.missing import isna
 
-from pandas.core import nanops, ops
+from pandas.core import ops
 from pandas.core.array_algos import masked_reductions
-from pandas.core.indexers import check_array_indexer
 from pandas.core.ops import invalid_comparison
 from pandas.core.ops.common import unpack_zerodim_and_defer
 from pandas.core.tools.numeric import to_numeric
@@ -417,19 +415,8 @@ def reconstruct(x):
         else:
             return reconstruct(result)
 
-    def __setitem__(self, key, value) -> None:
-        _is_scalar = is_scalar(value)
-        if _is_scalar:
-            value = [value]
-        value, mask = coerce_to_array(value, dtype=self.dtype)
-
-        if _is_scalar:
-            value = value[0]
-            mask = mask[0]
-
-        key = check_array_indexer(self, key)
-        self._data[key] = value
-        self._mask[key] = mask
+    def _coerce_to_array(self, value) -> Tuple[np.ndarray, np.ndarray]:
+        return coerce_to_array(value, dtype=self.dtype)
 
     def astype(self, dtype, copy: bool = True) -> ArrayLike:
         """
@@ -553,27 +540,6 @@ def cmp_method(self, other):
         name = f"__{op.__name__}__"
         return set_function_name(cmp_method, name, cls)
 
-    def _reduce(self, name: str, skipna: bool = True, **kwargs):
-        data = self._data
-        mask = self._mask
-
-        if name in {"sum", "prod", "min", "max"}:
-            op = getattr(masked_reductions, name)
-            return op(data, mask, skipna=skipna, **kwargs)
-
-        # coerce to a nan-aware float if needed
-        # (we explicitly use NaN within reductions)
-        if self._hasna:
-            data = self.to_numpy("float64", na_value=np.nan)
-
-        op = getattr(nanops, "nan" + name)
-        result = op(data, axis=0, skipna=skipna, mask=mask, **kwargs)
-
-        if np.isnan(result):
-            return libmissing.NA
-
-        return result
-
     def sum(self, skipna=True, min_count=0, **kwargs):
         nv.validate_sum((), kwargs)
         result = masked_reductions.sum(

pandas/core/arrays/masked.py

@@ -8,10 +8,17 @@
 from pandas.util._decorators import doc
 
 from pandas.core.dtypes.base import ExtensionDtype
-from pandas.core.dtypes.common import is_integer, is_object_dtype, is_string_dtype
+from pandas.core.dtypes.common import (
+    is_integer,
+    is_object_dtype,
+    is_scalar,
+    is_string_dtype,
+)
 from pandas.core.dtypes.missing import isna, notna
 
+from pandas.core import nanops
 from pandas.core.algorithms import _factorize_array, take
+from pandas.core.array_algos import masked_reductions
 from pandas.core.arrays import ExtensionArray, ExtensionOpsMixin
 from pandas.core.indexers import check_array_indexer
 
@@ -77,6 +84,23 @@ def __getitem__(self, item):
 
         return type(self)(self._data[item], self._mask[item])
 
+    def _coerce_to_array(self, values) -> Tuple[np.ndarray, np.ndarray]:
+        raise AbstractMethodError(self)
+
+    def __setitem__(self, key, value) -> None:
+        _is_scalar = is_scalar(value)
+        if _is_scalar:
+            value = [value]
+        value, mask = self._coerce_to_array(value)
+
+        if _is_scalar:
+            value = value[0]
+            mask = mask[0]
+
+        key = check_array_indexer(self, key)
+        self._data[key] = value
+        self._mask[key] = mask
+
     def __iter__(self):
         for i in range(len(self)):
             if self._mask[i]:
@@ -305,3 +329,24 @@ def value_counts(self, dropna: bool = True) -> "Series":
         counts = IntegerArray(counts, mask)
 
         return Series(counts, index=index)
+
+    def _reduce(self, name: str, skipna: bool = True, **kwargs):
+        data = self._data
+        mask = self._mask
+
+        if name in {"sum", "prod", "min", "max"}:
+            op = getattr(masked_reductions, name)
+            return op(data, mask, skipna=skipna, **kwargs)
+
+        # coerce to a nan-aware float if needed
+        # (we explicitly use NaN within reductions)
+        if self._hasna:
+            data = self.to_numpy("float64", na_value=np.nan)
+
+        op = getattr(nanops, "nan" + name)
+        result = op(data, axis=0, skipna=skipna, mask=mask, **kwargs)
+
+        if np.isnan(result):
+            return libmissing.NA
+
+        return result