CLN: remove unnecessary casting from Block methods (#38700)

Author: jbrockmendel

pandas/core/internals/blocks.py

@@ -26,7 +26,6 @@
     find_common_type,
     infer_dtype_from,
     infer_dtype_from_scalar,
-    maybe_box_datetimelike,
     maybe_downcast_numeric,
     maybe_downcast_to_dtype,
     maybe_infer_dtype_type,
@@ -746,11 +745,6 @@ def replace(
             return [self] if inplace else [self.copy()]
 
         values = self.values
-        if lib.is_scalar(to_replace) and isinstance(values, np.ndarray):
-            # The only non-DatetimeLike class that also has a non-trivial
-            #  try_coerce_args is ObjectBlock, but that overrides replace,
-            #  so does not get here.
-            to_replace = convert_scalar_for_putitemlike(to_replace, values.dtype)
 
         mask = missing.mask_missing(values, to_replace)
         if not mask.any():
@@ -845,7 +839,6 @@ def comp(s: Scalar, mask: np.ndarray, regex: bool = False) -> np.ndarray:
             if isna(s):
                 return ~mask
 
-            s = maybe_box_datetimelike(s)
             return compare_or_regex_search(self.values, s, regex, mask)
 
         if self.is_object:
@@ -919,8 +912,6 @@ def setitem(self, indexer, value):
                 arr = self.array_values().T
                 arr[indexer] = value
                 return self
-            elif lib.is_scalar(value):
-                value = convert_scalar_for_putitemlike(value, values.dtype)
 
         else:
             # current dtype cannot store value, coerce to common dtype
@@ -1067,9 +1058,6 @@ def putmask(self, mask, new, axis: int = 0) -> List["Block"]:
                 arr.putmask(mask, new)
                 return [self]
 
-            if lib.is_scalar(new):
-                new = convert_scalar_for_putitemlike(new, self.values.dtype)
-
             if transpose:
                 new_values = new_values.T
 

pandas/tests/series/methods/test_fillna.py

@@ -177,7 +177,7 @@ def test_fillna_downcast(self):
         expected = Series([1, 0])
         tm.assert_series_equal(result, expected)
 
-    def test_timedelta_fillna(self):
+    def test_timedelta_fillna(self, frame_or_series):
         # GH#3371
         ser = Series(
             [
@@ -188,9 +188,10 @@ def test_timedelta_fillna(self):
             ]
         )
         td = ser.diff()
+        obj = frame_or_series(td)
 
         # reg fillna
-        result = td.fillna(Timedelta(seconds=0))
+        result = obj.fillna(Timedelta(seconds=0))
         expected = Series(
             [
                 timedelta(0),
@@ -199,13 +200,14 @@ def test_timedelta_fillna(self):
                 timedelta(days=1, seconds=9 * 3600 + 60 + 1),
             ]
         )
-        tm.assert_series_equal(result, expected)
+        expected = frame_or_series(expected)
+        tm.assert_equal(result, expected)
 
         # interpreted as seconds, deprecated
         with pytest.raises(TypeError, match="Passing integers to fillna"):
-            td.fillna(1)
+            obj.fillna(1)
 
-        result = td.fillna(Timedelta(seconds=1))
+        result = obj.fillna(Timedelta(seconds=1))
         expected = Series(
             [
                 timedelta(seconds=1),
@@ -214,9 +216,10 @@ def test_timedelta_fillna(self):
                 timedelta(days=1, seconds=9 * 3600 + 60 + 1),
             ]
         )
-        tm.assert_series_equal(result, expected)
+        expected = frame_or_series(expected)
+        tm.assert_equal(result, expected)
 
-        result = td.fillna(timedelta(days=1, seconds=1))
+        result = obj.fillna(timedelta(days=1, seconds=1))
         expected = Series(
             [
                 timedelta(days=1, seconds=1),
@@ -225,9 +228,10 @@ def test_timedelta_fillna(self):
                 timedelta(days=1, seconds=9 * 3600 + 60 + 1),
             ]
         )
-        tm.assert_series_equal(result, expected)
+        expected = frame_or_series(expected)
+        tm.assert_equal(result, expected)
 
-        result = td.fillna(np.timedelta64(int(1e9)))
+        result = obj.fillna(np.timedelta64(int(1e9)))
         expected = Series(
             [
                 timedelta(seconds=1),
@@ -236,9 +240,10 @@ def test_timedelta_fillna(self):
                 timedelta(days=1, seconds=9 * 3600 + 60 + 1),
             ]
         )
-        tm.assert_series_equal(result, expected)
+        expected = frame_or_series(expected)
+        tm.assert_equal(result, expected)
 
-        result = td.fillna(NaT)
+        result = obj.fillna(NaT)
         expected = Series(
             [
                 NaT,
@@ -248,21 +253,27 @@ def test_timedelta_fillna(self):
             ],
             dtype="m8[ns]",
         )
-        tm.assert_series_equal(result, expected)
+        expected = frame_or_series(expected)
+        tm.assert_equal(result, expected)
 
         # ffill
         td[2] = np.nan
-        result = td.ffill()
+        obj = frame_or_series(td)
+        result = obj.ffill()
         expected = td.fillna(Timedelta(seconds=0))
         expected[0] = np.nan
-        tm.assert_series_equal(result, expected)
+        expected = frame_or_series(expected)
+
+        tm.assert_equal(result, expected)
 
         # bfill
         td[2] = np.nan
-        result = td.bfill()
+        obj = frame_or_series(td)
+        result = obj.bfill()
         expected = td.fillna(Timedelta(seconds=0))
         expected[2] = timedelta(days=1, seconds=9 * 3600 + 60 + 1)
-        tm.assert_series_equal(result, expected)
+        expected = frame_or_series(expected)
+        tm.assert_equal(result, expected)
 
     def test_datetime64_fillna(self):
 
@@ -553,7 +564,7 @@ def test_fillna_period(self):
         tm.assert_series_equal(res, exp)
         assert res.dtype == "Period[M]"
 
-    def test_fillna_dt64_timestamp(self):
+    def test_fillna_dt64_timestamp(self, frame_or_series):
         ser = Series(
             [
                 Timestamp("20130101"),
@@ -563,9 +574,10 @@ def test_fillna_dt64_timestamp(self):
             ]
         )
         ser[2] = np.nan
+        obj = frame_or_series(ser)
 
         # reg fillna
-        result = ser.fillna(Timestamp("20130104"))
+        result = obj.fillna(Timestamp("20130104"))
         expected = Series(
             [
                 Timestamp("20130101"),
@@ -574,11 +586,12 @@ def test_fillna_dt64_timestamp(self):
                 Timestamp("20130103 9:01:01"),
             ]
         )
-        tm.assert_series_equal(result, expected)
+        expected = frame_or_series(expected)
+        tm.assert_equal(result, expected)
 
-        result = ser.fillna(NaT)
-        expected = ser
-        tm.assert_series_equal(result, expected)
+        result = obj.fillna(NaT)
+        expected = obj
+        tm.assert_equal(result, expected)
 
     def test_fillna_dt64_non_nao(self):
         # GH#27419