ENH: Implement IntegerArray.sum

doc/source/whatsnew/v1.1.0.rst

@@ -601,6 +601,7 @@ Other
 - Bug in :meth:`Series.map` not raising on invalid ``na_action`` (:issue:`32815`)
 - Bug in :meth:`DataFrame.__dir__` caused a segfault when using unicode surrogates in a column name (:issue:`25509`)
 - Bug in :meth:`DataFrame.plot.scatter` caused an error when plotting variable marker sizes (:issue:`32904`)
+- :class:`IntegerArray` now implements the ``sum`` operation
 
 .. ---------------------------------------------------------------------------
 

pandas/core/arrays/integer.py

@@ -573,6 +573,12 @@ def _reduce(self, name: str, skipna: bool = True, **kwargs):
 
         return result
 
+    def sum(self, skipna: bool = True, min_count: int = 0):
+        result = masked_reductions.sum(
+            values=self._data, mask=self._mask, skipna=skipna, min_count=min_count
+        )
+        return result
+
     def _maybe_mask_result(self, result, mask, other, op_name: str):
         """
         Parameters

pandas/tests/arrays/integer/test_function.py

@@ -113,6 +113,17 @@ def test_value_counts_empty():
     tm.assert_series_equal(result, expected)
 
 
+@pytest.mark.parametrize("skipna", [True, False])
+@pytest.mark.parametrize("min_count", [0, 4])
+def test_integer_array_sum(skipna, min_count):
+    arr = pd.array([1, 2, 3, None], dtype="Int64")
+    result = arr.sum(skipna=skipna, min_count=min_count)
+    if skipna and min_count == 0:
+        assert result == 6
+    else:
+        assert result is pd.NA
+
+
 # TODO(jreback) - these need testing / are broken
 
 # shift