REF: avoid broadcasting of Series to DataFrame in ops for ArrayManager

pandas/core/frame.py

@@ -6674,8 +6674,6 @@ def _dispatch_frame_op(self, right, func: Callable, axis: Optional[int] = None):
             assert right.index.equals(self.columns)
 
             right = right._values
-            # maybe_align_as_frame ensures we do not have an ndarray here
-            assert not isinstance(right, np.ndarray)
 
             arrays = [
                 array_op(_left, _right)

pandas/core/ops/__init__.py

@@ -306,7 +306,11 @@ def to_series(right):
         left, right = left.align(
             right, join="outer", axis=axis, level=level, copy=False
         )
-        right = _maybe_align_series_as_frame(left, right, axis)
+
+        from pandas.core.internals import BlockManager
+
+        if isinstance(left._mgr, BlockManager):
+            right = _maybe_align_series_as_frame(left, right, axis)
 
     return left, right
 

pandas/tests/arithmetic/test_datetime64.py

@@ -1506,7 +1506,13 @@ def test_dt64arr_add_sub_DateOffset(self, box_with_array):
     @pytest.mark.parametrize("op", [operator.add, roperator.radd, operator.sub])
     @pytest.mark.parametrize("box_other", [True, False])
     def test_dt64arr_add_sub_offset_array(
-        self, tz_naive_fixture, box_with_array, box_other, op, other
+        self,
+        tz_naive_fixture,
+        box_with_array,
+        box_other,
+        op,
+        other,
+        using_array_manager,
     ):
         # GH#18849
         # GH#10699 array of offsets
@@ -1522,7 +1528,10 @@ def test_dt64arr_add_sub_offset_array(
         if box_other:
             other = tm.box_expected(other, box_with_array)
 
-        with tm.assert_produces_warning(PerformanceWarning):
+        warn = PerformanceWarning
+        if box_with_array is pd.DataFrame and not box_other and using_array_manager:
+            warn = None
+        with tm.assert_produces_warning(warn):
             res = op(dtarr, other)
 
         tm.assert_equal(res, expected)
@@ -2451,7 +2460,7 @@ def test_dti_addsub_offset_arraylike(
 
     @pytest.mark.parametrize("other_box", [pd.Index, np.array])
     def test_dti_addsub_object_arraylike(
-        self, tz_naive_fixture, box_with_array, other_box
+        self, tz_naive_fixture, box_with_array, other_box, using_array_manager
     ):
         tz = tz_naive_fixture
 
@@ -2463,14 +2472,18 @@ def test_dti_addsub_object_arraylike(
         expected = DatetimeIndex(["2017-01-31", "2017-01-06"], tz=tz_naive_fixture)
         expected = tm.box_expected(expected, xbox)
 
-        with tm.assert_produces_warning(PerformanceWarning):
+        warn = PerformanceWarning
+        if box_with_array is pd.DataFrame and using_array_manager:
+            warn = None
+
+        with tm.assert_produces_warning(warn):
             result = dtarr + other
         tm.assert_equal(result, expected)
 
         expected = DatetimeIndex(["2016-12-31", "2016-12-29"], tz=tz_naive_fixture)
         expected = tm.box_expected(expected, xbox)
 
-        with tm.assert_produces_warning(PerformanceWarning):
+        with tm.assert_produces_warning(warn):
             result = dtarr - other
         tm.assert_equal(result, expected)
 

pandas/tests/arithmetic/test_timedelta64.py

@@ -1323,7 +1323,7 @@ def test_td64arr_sub_timedeltalike(self, two_hours, box_with_array):
     # ------------------------------------------------------------------
     # __add__/__sub__ with DateOffsets and arrays of DateOffsets
 
-    def test_td64arr_add_offset_index(self, names, box_with_array):
+    def test_td64arr_add_offset_index(self, names, box_with_array, using_array_manager):
         # GH#18849, GH#19744
         box = box_with_array
         exname = get_expected_name(box, names)
@@ -1338,17 +1338,21 @@ def test_td64arr_add_offset_index(self, names, box_with_array):
         tdi = tm.box_expected(tdi, box)
         expected = tm.box_expected(expected, box)
 
-        with tm.assert_produces_warning(PerformanceWarning):
+        warn = PerformanceWarning
+        if box is DataFrame and using_array_manager:
+            warn = None
+
+        with tm.assert_produces_warning(warn):
             res = tdi + other
         tm.assert_equal(res, expected)
 
-        with tm.assert_produces_warning(PerformanceWarning):
+        with tm.assert_produces_warning(warn):
             res2 = other + tdi
         tm.assert_equal(res2, expected)
 
     # TODO: combine with test_td64arr_add_offset_index by parametrizing
     # over second box?
-    def test_td64arr_add_offset_array(self, box_with_array):
+    def test_td64arr_add_offset_array(self, box_with_array, using_array_manager):
         # GH#18849
         box = box_with_array
         tdi = TimedeltaIndex(["1 days 00:00:00", "3 days 04:00:00"])
@@ -1361,15 +1365,19 @@ def test_td64arr_add_offset_array(self, box_with_array):
         tdi = tm.box_expected(tdi, box)
         expected = tm.box_expected(expected, box)
 
-        with tm.assert_produces_warning(PerformanceWarning):
+        warn = PerformanceWarning
+        if box is DataFrame and using_array_manager:
+            warn = None
+
+        with tm.assert_produces_warning(warn):
             res = tdi + other
         tm.assert_equal(res, expected)
 
-        with tm.assert_produces_warning(PerformanceWarning):
+        with tm.assert_produces_warning(warn):
             res2 = other + tdi
         tm.assert_equal(res2, expected)
 
-    def test_td64arr_sub_offset_index(self, names, box_with_array):
+    def test_td64arr_sub_offset_index(self, names, box_with_array, using_array_manager):
         # GH#18824, GH#19744
         box = box_with_array
         xbox = box if box not in [tm.to_array, pd.array] else pd.Index
@@ -1385,11 +1393,15 @@ def test_td64arr_sub_offset_index(self, names, box_with_array):
         tdi = tm.box_expected(tdi, box)
         expected = tm.box_expected(expected, xbox)
 
-        with tm.assert_produces_warning(PerformanceWarning):
+        warn = PerformanceWarning
+        if box is DataFrame and using_array_manager:
+            warn = None
+
+        with tm.assert_produces_warning(warn):
             res = tdi - other
         tm.assert_equal(res, expected)
 
-    def test_td64arr_sub_offset_array(self, box_with_array):
+    def test_td64arr_sub_offset_array(self, box_with_array, using_array_manager):
         # GH#18824
         tdi = TimedeltaIndex(["1 days 00:00:00", "3 days 04:00:00"])
         other = np.array([offsets.Hour(n=1), offsets.Minute(n=-2)])
@@ -1401,11 +1413,17 @@ def test_td64arr_sub_offset_array(self, box_with_array):
         tdi = tm.box_expected(tdi, box_with_array)
         expected = tm.box_expected(expected, box_with_array)
 
-        with tm.assert_produces_warning(PerformanceWarning):
+        warn = PerformanceWarning
+        if box_with_array is DataFrame and using_array_manager:
+            warn = None
+
+        with tm.assert_produces_warning(warn):
             res = tdi - other
         tm.assert_equal(res, expected)
 
-    def test_td64arr_with_offset_series(self, names, box_with_array):
+    def test_td64arr_with_offset_series(
+        self, names, box_with_array, using_array_manager
+    ):
         # GH#18849
         box = box_with_array
         box2 = Series if box in [pd.Index, tm.to_array, pd.array] else box
@@ -1418,18 +1436,22 @@ def test_td64arr_with_offset_series(self, names, box_with_array):
         obj = tm.box_expected(tdi, box)
         expected_add = tm.box_expected(expected_add, box2)
 
-        with tm.assert_produces_warning(PerformanceWarning):
+        warn = PerformanceWarning
+        if box is DataFrame and using_array_manager:
+            warn = None
+
+        with tm.assert_produces_warning(warn):
             res = obj + other
         tm.assert_equal(res, expected_add)
 
-        with tm.assert_produces_warning(PerformanceWarning):
+        with tm.assert_produces_warning(warn):
             res2 = other + obj
         tm.assert_equal(res2, expected_add)
 
         expected_sub = Series([tdi[n] - other[n] for n in range(len(tdi))], name=exname)
         expected_sub = tm.box_expected(expected_sub, box2)
 
-        with tm.assert_produces_warning(PerformanceWarning):
+        with tm.assert_produces_warning(warn):
             res3 = obj - other
         tm.assert_equal(res3, expected_sub)
 
@@ -1460,7 +1482,7 @@ def test_td64arr_addsub_anchored_offset_arraylike(self, obox, box_with_array):
     # ------------------------------------------------------------------
     # Unsorted
 
-    def test_td64arr_add_sub_object_array(self, box_with_array):
+    def test_td64arr_add_sub_object_array(self, box_with_array, using_array_manager):
         box = box_with_array
         xbox = np.ndarray if box is pd.array else box
 
@@ -1469,7 +1491,11 @@ def test_td64arr_add_sub_object_array(self, box_with_array):
 
         other = np.array([Timedelta(days=1), offsets.Day(2), Timestamp("2000-01-04")])
 
-        with tm.assert_produces_warning(PerformanceWarning):
+        warn = PerformanceWarning
+        if box is DataFrame and using_array_manager:
+            warn = None
+
+        with tm.assert_produces_warning(warn):
             result = tdarr + other
 
         expected = pd.Index(
@@ -1480,10 +1506,10 @@ def test_td64arr_add_sub_object_array(self, box_with_array):
 
         msg = "unsupported operand type|cannot subtract a datelike"
         with pytest.raises(TypeError, match=msg):
-            with tm.assert_produces_warning(PerformanceWarning):
+            with tm.assert_produces_warning(warn):
                 tdarr - other
 
-        with tm.assert_produces_warning(PerformanceWarning):
+        with tm.assert_produces_warning(warn):
             result = other - tdarr
 
         expected = pd.Index([Timedelta(0), Timedelta(0), Timestamp("2000-01-01")])
@@ -2051,9 +2077,7 @@ def test_td64arr_rmul_numeric_array(self, box_with_array, vector, any_real_dtype
         [np.array([20, 30, 40]), pd.Index([20, 30, 40]), Series([20, 30, 40])],
         ids=lambda x: type(x).__name__,
     )
-    def test_td64arr_div_numeric_array(
-        self, box_with_array, vector, any_real_dtype, using_array_manager
-    ):
+    def test_td64arr_div_numeric_array(self, box_with_array, vector, any_real_dtype):
         # GH#4521
         # divide/multiply by integers
         xbox = get_upcast_box(box_with_array, vector)
@@ -2089,15 +2113,6 @@ def test_td64arr_div_numeric_array(
             expected = pd.Index(expected)  # do dtype inference
             expected = tm.box_expected(expected, xbox)
             assert tm.get_dtype(expected) == "m8[ns]"
-
-            if using_array_manager and box_with_array is DataFrame:
-                # TODO the behaviour is buggy here (third column with all-NaT
-                # as result doesn't get preserved as timedelta64 dtype).
-                # Reported at https://github.com/pandas-dev/pandas/issues/39750
-                # Changing the expected instead of xfailing to continue to test
-                # the correct behaviour for the other columns
-                expected[2] = Series([NaT, NaT], dtype=object)
-
             tm.assert_equal(result, expected)
 
         with pytest.raises(TypeError, match=pattern):