CoW: Remove todos that aren't necessary (#56169)

Author: phofl

pandas/tests/apply/test_invalid_arg.py

@@ -152,7 +152,7 @@ def test_transform_axis_1_raises():
 
 # TODO(CoW-warn) should not need to warn
 @pytest.mark.filterwarnings("ignore:Setting a value on a view:FutureWarning")
-def test_apply_modify_traceback():
+def test_apply_modify_traceback(warn_copy_on_write):
     data = DataFrame(
         {
             "A": [
@@ -214,7 +214,8 @@ def transform2(row):
 
     msg = "'float' object has no attribute 'startswith'"
     with pytest.raises(AttributeError, match=msg):
-        data.apply(transform, axis=1)
+        with tm.assert_cow_warning(warn_copy_on_write):
+            data.apply(transform, axis=1)
 
 
 @pytest.mark.parametrize(

pandas/tests/copy_view/test_constructors.py

@@ -297,7 +297,6 @@ def test_dataframe_from_series_or_index(
     if using_copy_on_write:
         assert not df._mgr._has_no_reference(0)
 
-    # TODO(CoW-warn) should not warn for an index?
     with tm.assert_cow_warning(warn_copy_on_write):
         df.iloc[0, 0] = data[-1]
     if using_copy_on_write:

pandas/tests/copy_view/test_indexing.py

@@ -913,7 +913,6 @@ def test_del_frame(backend, using_copy_on_write, warn_copy_on_write):
     tm.assert_frame_equal(df2, df_orig[["a", "c"]])
     df2._mgr._verify_integrity()
 
-    # TODO(CoW-warn) false positive, this should not warn?
     with tm.assert_cow_warning(warn_copy_on_write and dtype_backend == "numpy"):
         df.loc[0, "b"] = 200
     assert np.shares_memory(get_array(df, "a"), get_array(df2, "a"))