DEPR: Series/DataFrame.append (#35407)

pandas/tests/generic/test_duplicate_labels.py

@@ -294,15 +294,11 @@ def test_setting_allows_duplicate_labels_raises(self, data):
 
         assert data.flags.allows_duplicate_labels is True
 
-    @pytest.mark.filterwarnings("ignore:.*append method is deprecated.*:FutureWarning")
-    @pytest.mark.parametrize(
-        "func", [operator.methodcaller("append", pd.Series(0, index=["a", "b"]))]
-    )
-    def test_series_raises(self, func):
+    def test_series_raises(self):
         s = pd.Series([0, 1], index=["a", "b"]).set_flags(allows_duplicate_labels=False)
         msg = "Index has duplicates."
         with pytest.raises(pd.errors.DuplicateLabelError, match=msg):
-            func(s)
+            pd.concat([pd.Series(0, index=["a", "b"]), s])
 
     @pytest.mark.parametrize(
         "getter, target",

pandas/tests/indexing/test_partial.py

@@ -361,7 +361,7 @@ def test_partial_setting_mixed_dtype(self):
 
         s = df.loc[1].copy()
         s.name = 2
-        expected = df._append(s)
+        expected = pd.concat([df, DataFrame(s).T.infer_objects()])
 
         df.loc[2] = df.loc[1]
         tm.assert_frame_equal(df, expected)
@@ -538,7 +538,8 @@ def test_partial_set_invalid(self):
         # allow object conversion here
         df = orig.copy()
         df.loc["a", :] = df.iloc[0]
-        exp = orig._append(Series(df.iloc[0], name="a"))
+        s = Series(df.iloc[0], name="a")
+        exp = pd.concat([orig, DataFrame(s).T.infer_objects()])
         tm.assert_frame_equal(df, exp)
         tm.assert_index_equal(df.index, Index(orig.index.tolist() + ["a"]))
         assert df.index.dtype == "object"

pandas/tests/reshape/concat/test_categorical.py

@@ -1,5 +1,4 @@
 import numpy as np
-import pytest
 
 from pandas.core.dtypes.dtypes import CategoricalDtype
 
@@ -185,7 +184,6 @@ def test_concat_categorical_unchanged(self):
         )
         tm.assert_equal(result, expected)
 
-    @pytest.mark.filterwarnings("ignore:.*append method is deprecated.*:FutureWarning")
     def test_categorical_concat_gh7864(self):
         # GH 7864
         # make sure ordering is preserved
@@ -202,9 +200,6 @@ def test_categorical_concat_gh7864(self):
         dfx = pd.concat([df1, df2])
         tm.assert_index_equal(df["grade"].cat.categories, dfx["grade"].cat.categories)
 
-        dfa = df1.append(df2)
-        tm.assert_index_equal(df["grade"].cat.categories, dfa["grade"].cat.categories)
-
     def test_categorical_index_upcast(self):
         # GH 17629
         # test upcasting to object when concatinating on categorical indexes

pandas/tests/reshape/concat/test_concat.py

@@ -219,7 +219,6 @@ def test_concat_keys_levels_no_overlap(self):
         with pytest.raises(ValueError, match=msg):
             concat([df, df2], keys=["one", "two"], levels=[["foo", "bar", "baz"]])
 
-    @pytest.mark.filterwarnings("ignore:.*append method is deprecated.*:FutureWarning")
     def test_crossed_dtypes_weird_corner(self):
         columns = ["A", "B", "C", "D"]
         df1 = DataFrame(
@@ -242,7 +241,7 @@ def test_crossed_dtypes_weird_corner(self):
             columns=columns,
         )
 
-        appended = df1.append(df2, ignore_index=True)
+        appended = concat([df1, df2], ignore_index=True)
         expected = DataFrame(
             np.concatenate([df1.values, df2.values], axis=0), columns=columns
         )

pandas/tests/reshape/concat/test_index.py

@@ -141,7 +141,6 @@ def test_default_index(self):
         exp = DataFrame([[1, 5, 3, 7], [2, 6, 4, 8]])
         tm.assert_frame_equal(res, exp, check_index_type=True, check_column_type=True)
 
-    @pytest.mark.filterwarnings("ignore:.*append method is deprecated.*:FutureWarning")
     def test_dups_index(self):
         # GH 4771
 
@@ -179,16 +178,12 @@ def test_dups_index(self):
         tm.assert_frame_equal(result.iloc[10:], df)
 
         # append
-        result = df.iloc[0:8, :].append(df.iloc[8:])
+        result = concat([df.iloc[0:8, :], df.iloc[8:]])
         tm.assert_frame_equal(result, df)
 
-        result = df.iloc[0:8, :].append(df.iloc[8:9]).append(df.iloc[9:10])
+        result = concat([df.iloc[0:8, :], df.iloc[8:9], df.iloc[9:10]])
         tm.assert_frame_equal(result, df)
 
-        expected = concat([df, df], axis=0)
-        result = df.append(df)
-        tm.assert_frame_equal(result, expected)
-
 
 class TestMultiIndexConcat:
     def test_concat_multiindex_with_keys(self, multiindex_dataframe_random_data):

pandas/tests/reshape/merge/test_merge.py

@@ -682,15 +682,16 @@ def _constructor(self):
 
         assert isinstance(result, NotADataFrame)
 
-    @pytest.mark.filterwarnings("ignore:.*append method is deprecated.*:FutureWarning")
     def test_join_append_timedeltas(self):
         # timedelta64 issues with join/merge
         # GH 5695
 
-        d = {"d": datetime(2013, 11, 5, 5, 56), "t": timedelta(0, 22500)}
+        d = DataFrame.from_dict(
+            {"d": [datetime(2013, 11, 5, 5, 56)], "t": [timedelta(0, 22500)]}
+        )
         df = DataFrame(columns=list("dt"))
-        df = df.append(d, ignore_index=True)
-        result = df.append(d, ignore_index=True)
+        df = concat([df, d], ignore_index=True)
+        result = concat([df, d], ignore_index=True)
         expected = DataFrame(
             {
                 "d": [datetime(2013, 11, 5, 5, 56), datetime(2013, 11, 5, 5, 56)],