Move and rename tests

pandas/tests/frame/indexing/test_setitem.py

@@ -299,40 +299,6 @@ def test_iloc_setitem_bool_indexer(self, klass):
         expected = DataFrame({"flag": ["x", "y", "z"], "value": [2, 3, 4]})
         tm.assert_frame_equal(df, expected)
 
-    @pytest.mark.parametrize("dtype", ["int64", "Int64"])
-    def test_setitem_complete_columns_different_dtypes(self, dtype):
-        # GH: 20635
-        df = DataFrame({"A": ["a", "b"], "B": ["1", "2"], "C": ["3", "4"], "D": [1, 2]})
-        rhs = df[["B", "C"]].astype("int64").astype(dtype)
-        df.loc[:, ["B", "C"]] = rhs
-        expected = DataFrame({"A": ["a", "b"], "B": [1, 2], "C": [3, 4], "D": [1, 2]})
-        expected[["B", "C"]] = expected[["B", "C"]].astype(dtype)
-        tm.assert_frame_equal(df, expected)
-
-    def test_setitem_single_column_as_series_different_dtype(self):
-        # GH: 20635
-        df = DataFrame({"A": ["a", "b"], "B": ["1", "2"], "C": ["3", "4"]})
-        df.loc[:, "C"] = df["C"].astype("int64")
-        expected = DataFrame({"A": ["a", "b"], "B": ["1", "2"], "C": [3, 4]})
-        tm.assert_frame_equal(df, expected)
-
-    def test_setitem_conversion_to_datetime(self):
-        # GH: 20511
-        df = DataFrame(
-            [["2015-01-01", "2016-01-01"], ["2016-01-01", "2015-01-01"]],
-            columns=["date0", "date1"],
-        )
-        df.iloc[:, [0]] = df.iloc[:, [0]].apply(
-            lambda x: to_datetime(x, errors="coerce")
-        )
-        expected = DataFrame(
-            {
-                "date0": [to_datetime("2015-01-01"), to_datetime("2016-01-01")],
-                "date1": ["2016-01-01", "2015-01-01"],
-            }
-        )
-        tm.assert_frame_equal(df, expected)
-
     def test_setitem_scalar_dtype_change(self):
         # GH#27583
         df = DataFrame({"a": [0.0], "b": [0.0]})

pandas/tests/indexing/test_iloc.py

@@ -17,6 +17,7 @@
     concat,
     date_range,
     isna,
+    to_datetime,
 )
 import pandas._testing as tm
 from pandas.api.types import is_scalar
@@ -801,6 +802,23 @@ def test_iloc_setitem_empty_frame_raises_with_3d_ndarray(self):
         with pytest.raises(ValueError, match=msg):
             obj.iloc[nd3] = 0
 
+    def test_setitem_conversion_to_datetime(self):
+        # GH: 20511
+        df = DataFrame(
+            [["2015-01-01", "2016-01-01"], ["2016-01-01", "2015-01-01"]],
+            columns=["date0", "date1"],
+        )
+        df.iloc[:, [0]] = df.iloc[:, [0]].apply(
+            lambda x: to_datetime(x, errors="coerce")
+        )
+        expected = DataFrame(
+            {
+                "date0": [to_datetime("2015-01-01"), to_datetime("2016-01-01")],
+                "date1": ["2016-01-01", "2015-01-01"],
+            }
+        )
+        tm.assert_frame_equal(df, expected)
+
 
 class TestILocErrors:
     # NB: this test should work for _any_ Series we can pass as

pandas/tests/indexing/test_loc.py

@@ -1127,6 +1127,23 @@ def test_loc_setitem_listlike_with_timedelta64index(self, indexer, expected):
 
         tm.assert_frame_equal(expected, df)
 
+    def test_setitem_null_slice_single_column_series_value_different_dtype(self):
+        # GH: 20635
+        df = DataFrame({"A": ["a", "b"], "B": ["1", "2"], "C": ["3", "4"]})
+        df.loc[:, "C"] = df["C"].astype("int64")
+        expected = DataFrame({"A": ["a", "b"], "B": ["1", "2"], "C": [3, 4]})
+        tm.assert_frame_equal(df, expected)
+
+    @pytest.mark.parametrize("dtype", ["int64", "Int64"])
+    def test_setitem_null_slice_different_dtypes(self, dtype):
+        # GH: 20635
+        df = DataFrame({"A": ["a", "b"], "B": ["1", "2"], "C": ["3", "4"], "D": [1, 2]})
+        rhs = df[["B", "C"]].astype("int64").astype(dtype)
+        df.loc[:, ["B", "C"]] = rhs
+        expected = DataFrame({"A": ["a", "b"], "B": [1, 2], "C": [3, 4], "D": [1, 2]})
+        expected[["B", "C"]] = expected[["B", "C"]].astype(dtype)
+        tm.assert_frame_equal(df, expected)
+
 
 class TestLocWithMultiIndex:
     @pytest.mark.parametrize(
@@ -1995,6 +2012,14 @@ def test_loc_setitem_dt64tz_values(self):
         result = s2["a"]
         assert result == expected
 
+    @pytest.mark.parametrize("dtype", ["int64", "Int64"])
+    def test_setitem_series_null_slice_different_dtypes(self, dtype):
+        # GH: 20635
+        ser = Series(["3", "4"], name="A")
+        ser.loc[:] = ser.astype("int64").astype(dtype)
+        expected = Series([3, 4], name="A", dtype=dtype)
+        tm.assert_series_equal(ser, expected)
+
 
 @pytest.mark.parametrize("value", [1, 1.5])
 def test_loc_int_in_object_index(frame_or_series, value):

pandas/tests/series/indexing/test_setitem.py

@@ -219,14 +219,6 @@ def test_setitem_nan_casts(self):
         ser[:5] = np.nan
         tm.assert_series_equal(ser, expected)
 
-    @pytest.mark.parametrize("dtype", ["int64", "Int64"])
-    def test_setitem_assigning_different_dtype(self, dtype):
-        # GH: 20635
-        ser = Series(["3", "4"], name="A")
-        ser.loc[:] = ser.astype("int64").astype(dtype)
-        expected = Series([3, 4], name="A", dtype=dtype)
-        tm.assert_series_equal(ser, expected)
-
 
 class TestSetitemWithExpansion:
     def test_setitem_empty_series(self):