update tests for non-CoW and warn mode

Author: jorisvandenbossche

pandas/tests/frame/indexing/test_indexing.py

@@ -1500,6 +1500,7 @@ def test_set_2d_casting_date_to_int(self, col, indexer):
         )
         tm.assert_frame_equal(df, expected)
 
+    @pytest.mark.filterwarnings("ignore:Setting a value on a view:FutureWarning")
     @pytest.mark.parametrize("has_ref", [True, False])
     @pytest.mark.parametrize("col", [{}, {"name": "a"}])
     def test_loc_setitem_reordering_with_all_true_indexer(self, col, has_ref):

pandas/tests/frame/indexing/test_setitem.py

@@ -3,6 +3,7 @@
 import numpy as np
 import pytest
 
+from pandas.errors import SettingWithCopyWarning
 import pandas.util._test_decorators as td
 
 from pandas.core.dtypes.base import _registry as ea_registry
@@ -1400,7 +1401,7 @@ def test_frame_setitem_empty_dataframe(self):
         )
         tm.assert_frame_equal(df, expected)
 
-    def test_iloc_setitem_view_2dblock(self):
+    def test_iloc_setitem_view_2dblock(self, using_copy_on_write, warn_copy_on_write):
         # https://github.com/pandas-dev/pandas/issues/60309
         df_parent = DataFrame(
             {
@@ -1414,19 +1415,34 @@ def test_iloc_setitem_view_2dblock(self):
         df = df_parent[["B", "C"]]
 
         # Perform the iloc operation
-        df.iloc[[1, 3], :] = [[2, 2], [2, 2]]
-
-        # Check that original DataFrame is unchanged
-        tm.assert_frame_equal(df_parent, df_orig)
+        if using_copy_on_write:
+            df.iloc[[1, 3], :] = [[2, 2], [2, 2]]
+
+            # Check that original DataFrame is unchanged
+            tm.assert_frame_equal(df_parent, df_orig)
+        elif warn_copy_on_write:
+            # TODO(COW): should this warn?
+            # with tm.assert_cow_warning(warn_copy_on_write):
+            df.iloc[[1, 3], :] = [[2, 2], [2, 2]]
+        else:
+            with pd.option_context("chained_assignment", "warn"):
+                with tm.assert_produces_warning(SettingWithCopyWarning):
+                    df.iloc[[1, 3], :] = [[2, 2], [2, 2]]
 
         # Check that df is modified correctly
         expected = DataFrame({"B": [2, 2, 2, 2], "C": [3, 2, 1, 2]}, index=df.index)
         tm.assert_frame_equal(df, expected)
 
         # with setting to subset of columns
         df = df_parent[["B", "C", "D"]]
-        df.iloc[[1, 3], 0:3:2] = [[2, 2], [2, 2]]
-        tm.assert_frame_equal(df_parent, df_orig)
+        if using_copy_on_write or warn_copy_on_write:
+            df.iloc[[1, 3], 0:3:2] = [[2, 2], [2, 2]]
+            tm.assert_frame_equal(df_parent, df_orig)
+        else:
+            with pd.option_context("chained_assignment", "warn"):
+                with tm.assert_produces_warning(SettingWithCopyWarning):
+                    df.iloc[[1, 3], 0:3:2] = [[2, 2], [2, 2]]
+
         expected = DataFrame(
             {"B": [2, 2, 2, 2], "C": [3, 6, 1, 7], "D": [8, 2, 10, 2]}, index=df.index
         )
@@ -1448,7 +1464,9 @@ def test_iloc_setitem_view_2dblock(self):
             ),
         ],
     )
-    def test_setitem_2dblock_with_ref(self, indexer, value):
+    def test_setitem_2dblock_with_ref(
+        self, indexer, value, using_copy_on_write, warn_copy_on_write
+    ):
         # https://github.com/pandas-dev/pandas/issues/60309
         arr = np.arange(12).reshape(3, 4)
 
@@ -1459,10 +1477,12 @@ def test_setitem_2dblock_with_ref(self, indexer, value):
         df_orig = df_parent.copy()
         df = df_parent[:]
 
-        df.iloc[indexer] = value
+        with tm.assert_cow_warning(warn_copy_on_write):
+            df.iloc[indexer] = value
 
         # Check that original DataFrame is unchanged
-        tm.assert_frame_equal(df_parent, df_orig)
+        if using_copy_on_write:
+            tm.assert_frame_equal(df_parent, df_orig)
 
         # Check that df is modified correctly
         arr[indexer] = value

pandas/tests/indexing/test_iloc.py

@@ -104,6 +104,7 @@ def test_iloc_setitem_fullcol_categorical(self, indexer, key, using_array_manage
         expected = DataFrame({0: Series(cat.astype(object), dtype=object), 1: range(3)})
         tm.assert_frame_equal(df, expected)
 
+    @pytest.mark.filterwarnings("ignore:Setting a value on a view:FutureWarning")
     @pytest.mark.parametrize("has_ref", [True, False])
     @pytest.mark.parametrize("box", [array, Series])
     def test_iloc_setitem_ea_inplace(
@@ -432,6 +433,7 @@ def test_iloc_getitem_slice_dups(self):
         tm.assert_frame_equal(df.iloc[10:, :2], df2)
         tm.assert_frame_equal(df.iloc[10:, 2:], df1)
 
+    @pytest.mark.filterwarnings("ignore:Setting a value on a view:FutureWarning")
     @pytest.mark.parametrize("has_ref", [True, False])
     def test_iloc_setitem(self, warn_copy_on_write, has_ref):
         df = DataFrame(
@@ -457,6 +459,7 @@ def test_iloc_setitem(self, warn_copy_on_write, has_ref):
         expected = Series([0, 1, 0], index=[4, 5, 6])
         tm.assert_series_equal(s, expected)
 
+    @pytest.mark.filterwarnings("ignore:Setting a value on a view:FutureWarning")
     @pytest.mark.parametrize("has_ref", [True, False])
     def test_iloc_setitem_axis_argument(self, has_ref):
         # GH45032
@@ -478,6 +481,7 @@ def test_iloc_setitem_axis_argument(self, has_ref):
         df.iloc(axis=1)[2] = 5
         tm.assert_frame_equal(df, expected)
 
+    @pytest.mark.filterwarnings("ignore:Setting a value on a view:FutureWarning")
     @pytest.mark.parametrize("has_ref", [True, False])
     def test_iloc_setitem_list(self, has_ref):
         # setitem with an iloc list
@@ -686,6 +690,7 @@ def test_iloc_getitem_doc_issue(self, using_array_manager):
         expected = DataFrame(arr[1:5, 2:4], index=index[1:5], columns=columns[2:4])
         tm.assert_frame_equal(result, expected)
 
+    @pytest.mark.filterwarnings("ignore:Setting a value on a view:FutureWarning")
     @pytest.mark.parametrize("has_ref", [True, False])
     def test_iloc_setitem_series(self, has_ref):
         df = DataFrame(
@@ -723,6 +728,7 @@ def test_iloc_setitem_series(self, has_ref):
         expected = Series([0, 1, 2, 3, 4, 5])
         tm.assert_series_equal(result, expected)
 
+    @pytest.mark.filterwarnings("ignore:Setting a value on a view:FutureWarning")
     @pytest.mark.parametrize("has_ref", [True, False])
     def test_iloc_setitem_list_of_lists(self, has_ref):
         # GH 7551
@@ -745,6 +751,7 @@ def test_iloc_setitem_list_of_lists(self, has_ref):
         expected = DataFrame({"A": ["a", "b", "x", "y", "e"], "B": [5, 6, 11, 13, 9]})
         tm.assert_frame_equal(df, expected)
 
+    @pytest.mark.filterwarnings("ignore:Setting a value on a view:FutureWarning")
     @pytest.mark.parametrize("has_ref", [True, False])
     @pytest.mark.parametrize("indexer", [[0], slice(None, 1, None), np.array([0])])
     @pytest.mark.parametrize("value", [["Z"], np.array(["Z"])])
@@ -1062,6 +1069,7 @@ 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.filterwarnings("ignore:Setting a value on a view:FutureWarning")
     @pytest.mark.parametrize("has_ref", [True, False])
     @pytest.mark.parametrize("indexer", [[1], slice(1, 2)])
     def test_iloc_setitem_pure_position_based(self, indexer, has_ref):
@@ -1074,6 +1082,7 @@ def test_iloc_setitem_pure_position_based(self, indexer, has_ref):
         expected = DataFrame({"a": [1, 2, 3], "b": [11, 12, 13], "c": [7, 8, 9]})
         tm.assert_frame_equal(df2, expected)
 
+    @pytest.mark.filterwarnings("ignore:Setting a value on a view:FutureWarning")
     @pytest.mark.parametrize("has_ref", [True, False])
     def test_iloc_setitem_dictionary_value(self, has_ref):
         # GH#37728
@@ -1302,6 +1311,7 @@ def test_iloc_float_raises(
             ):
                 obj.iloc[3.0] = 0
 
+    @pytest.mark.filterwarnings("ignore:Setting a value on a view:FutureWarning")
     @pytest.mark.parametrize("has_ref", [True, False])
     def test_iloc_getitem_setitem_fancy_exceptions(self, float_frame, has_ref):
         with pytest.raises(IndexingError, match="Too many indexers"):

pandas/tests/indexing/test_loc.py

@@ -755,6 +755,7 @@ def test_loc_modify_datetime(self):
 
         tm.assert_frame_equal(df, expected)
 
+    @pytest.mark.filterwarnings("ignore:Setting a value on a view:FutureWarning")
     @pytest.mark.parametrize("has_ref", [True, False])
     def test_loc_setitem_frame_with_reindex(self, has_ref):
         # GH#6254 setting issue
@@ -791,6 +792,7 @@ def test_loc_setitem_frame_with_inverted_slice(self):
         expected = DataFrame({"A": [3.0, 2.0, 1.0], "B": "string"}, index=[1, 2, 3])
         tm.assert_frame_equal(df, expected)
 
+    @pytest.mark.filterwarnings("ignore:Setting a value on a view:FutureWarning")
     @pytest.mark.parametrize("has_ref", [True, False])
     def test_loc_setitem_empty_frame(self, has_ref):
         # GH#6252 setting with an empty frame
@@ -819,6 +821,7 @@ def test_loc_setitem_empty_frame(self, has_ref):
         )
         tm.assert_frame_equal(df, expected)
 
+    @pytest.mark.filterwarnings("ignore:Setting a value on a view:FutureWarning")
     @pytest.mark.parametrize("has_ref", [True, False])
     def test_loc_setitem_frame(self, has_ref):
         df = DataFrame(