GH refs

Author: rhshadrach

doc/source/whatsnew/v2.3.0.rst

@@ -107,13 +107,13 @@ Conversion
 
 Strings
 ^^^^^^^
+- Bug in :meth:`DataFrame.sum` with ``axis=1``, :meth:`.DataFrameGroupBy.sum` or :meth:`.SeriesGroupBy.sum` with ``skipna=True``, and :meth:`.Resampler.sum` on :class:`StringDtype` with all NA values resulted in ``0`` and is now the empty string ``""`` (:issue:`60229`)
 - Bug in :meth:`Series.__pos__` and :meth:`DataFrame.__pos__` did not raise for :class:`StringDtype` with ``storage="pyarrow"`` (:issue:`60710`)
 - Bug in :meth:`Series.rank` for :class:`StringDtype` with ``storage="pyarrow"`` incorrectly returning integer results in case of ``method="average"`` and raising an error if it would truncate results (:issue:`59768`)
 - Bug in :meth:`Series.replace` with :class:`StringDtype` when replacing with a non-string value was not upcasting to ``object`` dtype (:issue:`60282`)
 - Bug in :meth:`Series.str.replace` when ``n < 0`` for :class:`StringDtype` with ``storage="pyarrow"`` (:issue:`59628`)
 - Bug in ``ser.str.slice`` with negative ``step`` with :class:`ArrowDtype` and :class:`StringDtype` with ``storage="pyarrow"`` giving incorrect results (:issue:`59710`)
 - Bug in the ``center`` method on :class:`Series` and :class:`Index` object ``str`` accessors with pyarrow-backed dtype not matching the python behavior in corner cases with an odd number of fill characters (:issue:`54792`)
-- Bug in :meth:`DataFrame.sum` with ``axis=1``, :meth:`.DataFrameGroupBy.sum` or :meth:`.SeriesGroupBy.sum` with ``skipna=True``, and :meth:`.Resampler.sum` on :class:`StringDtype` with all NA values resulted in ``0`` and is now the empty string ``""`` (:issue:`???`)
 
 Interval
 ^^^^^^^^

pandas/core/arrays/base.py

@@ -2631,6 +2631,8 @@ def _groupby_op(
 
             arr = self
             if op.how == "sum":
+                # https://github.com/pandas-dev/pandas/issues/60229
+                # All NA should result in the empty string.
                 assert "skipna" in kwargs
                 if kwargs["skipna"] and min_count == 0:
                     arr = arr.fillna("")

pandas/tests/frame/test_reductions.py

@@ -837,7 +837,7 @@ def test_axis_1_empty(self, all_reductions, index):
 
     @pytest.mark.parametrize("min_count", [0, 1])
     def test_axis_1_sum_na(self, string_dtype_no_object, skipna, min_count):
-        # GH#???
+        # https://github.com/pandas-dev/pandas/issues/60229
         dtype = string_dtype_no_object
         df = DataFrame({"a": [pd.NA]}, dtype=dtype)
         result = df.sum(axis=1, skipna=skipna, min_count=min_count)

pandas/tests/groupby/test_reductions.py

@@ -957,7 +957,7 @@ def test_min_empty_string_dtype(func, string_dtype_no_object):
 
 @pytest.mark.parametrize("min_count", [0, 1])
 def test_string_dtype_empty_sum(string_dtype_no_object, skipna, min_count):
-    # GH#???
+    # https://github.com/pandas-dev/pandas/issues/60229
     dtype = string_dtype_no_object
     df = DataFrame({"a": ["x"], "b": [pd.NA]}, dtype=dtype)
     gb = df.groupby("a")

pandas/tests/resample/test_base.py

@@ -225,7 +225,7 @@ def test_resample_empty_series(freq, index, resample_method):
 
 @pytest.mark.parametrize("min_count", [0, 1])
 def test_resample_empty_sum_string(string_dtype_no_object, min_count):
-    # GH#???
+    # https://github.com/pandas-dev/pandas/issues/60229
     dtype = string_dtype_no_object
     ser = Series(
         pd.NA,

pandas/tests/resample/test_resampler_grouper.py

@@ -498,7 +498,7 @@ def test_resample_groupby_agg_object_dtype_all_nan(consolidate):
 def test_groupby_resample_empty_sum_string(
     string_dtype_no_object, test_frame, min_count
 ):
-    # GH#???
+    # https://github.com/pandas-dev/pandas/issues/60229
     dtype = string_dtype_no_object
     test_frame = test_frame.assign(B=pd.array([pd.NA] * len(test_frame), dtype=dtype))
     gbrs = test_frame.groupby("A").resample("40s")