CLN: __repr__ tests (#55798)

* misplaced tests

* CLN: repr smoke tests

* misplaced testS

* parametrize smoke tests

* CLN: smoke test repr

* misplaced tests

pandas/tests/frame/indexing/test_getitem.py

@@ -42,9 +42,6 @@ def test_getitem_periodindex(self):
         ts = df[rng[0]]
         tm.assert_series_equal(ts, df.iloc[:, 0])
 
-        # GH#1211; smoketest unrelated to the rest of this test
-        repr(df)
-
         ts = df["1/1/2000"]
         tm.assert_series_equal(ts, df.iloc[:, 0])
 
@@ -372,8 +369,6 @@ def test_getitem_boolean_series_with_duplicate_columns(self, df_dup_cols):
         result = df[df.C > 6]
 
         tm.assert_frame_equal(result, expected)
-        result.dtypes
-        str(result)
 
     def test_getitem_boolean_frame_with_duplicate_columns(self, df_dup_cols):
         # where
@@ -388,8 +383,6 @@ def test_getitem_boolean_frame_with_duplicate_columns(self, df_dup_cols):
         result = df[df > 6]
 
         tm.assert_frame_equal(result, expected)
-        result.dtypes
-        str(result)
 
     def test_getitem_empty_frame_with_boolean(self):
         # Test for issue GH#11859

pandas/tests/frame/indexing/test_indexing.py

@@ -511,7 +511,6 @@ def test_setitem_None(self, float_frame):
             float_frame.loc[:, None], float_frame["A"], check_names=False
         )
         tm.assert_series_equal(float_frame[None], float_frame["A"], check_names=False)
-        repr(float_frame)
 
     def test_loc_setitem_boolean_mask_allfalse(self):
         # GH 9596

pandas/tests/frame/indexing/test_insert.py

@@ -51,14 +51,12 @@ def test_insert_column_bug_4032(self):
         df.insert(0, "a", [1, 2])
         result = df.rename(columns={})
 
-        str(result)
         expected = DataFrame([[1, 1.1], [2, 2.2]], columns=["a", "b"])
         tm.assert_frame_equal(result, expected)
 
         df.insert(0, "c", [1.3, 2.3])
         result = df.rename(columns={})
 
-        str(result)
         expected = DataFrame([[1.3, 1, 1.1], [2.3, 2, 2.2]], columns=["c", "a", "b"])
         tm.assert_frame_equal(result, expected)
 

pandas/tests/frame/indexing/test_setitem.py

@@ -868,8 +868,6 @@ def test_setitem_with_expansion_categorical_dtype(self):
 
         # setting with a Categorical
         df["D"] = cat
-        str(df)
-
         result = df.dtypes
         expected = Series(
             [np.dtype("int32"), CategoricalDtype(categories=labels, ordered=False)],
@@ -879,8 +877,6 @@ def test_setitem_with_expansion_categorical_dtype(self):
 
         # setting with a Series
         df["E"] = ser
-        str(df)
-
         result = df.dtypes
         expected = Series(
             [

pandas/tests/frame/methods/test_rename.py

@@ -387,8 +387,6 @@ def test_rename_with_duplicate_columns(self):
         # TODO: can we construct this without merge?
         k = merge(df4, df5, how="inner", left_index=True, right_index=True)
         result = k.rename(columns={"TClose_x": "TClose", "TClose_y": "QT_Close"})
-        str(result)
-        result.dtypes
 
         expected = DataFrame(
             [[0.0454, 22.02, 0.0422, 20130331, 600809, "饡驦", 30.01]],

pandas/tests/frame/test_arithmetic.py

@@ -689,8 +689,6 @@ def test_arithmetic_with_duplicate_columns(self, op):
         df.columns = ["A", "A"]
         result = getattr(df, op)(df)
         tm.assert_frame_equal(result, expected)
-        str(result)
-        result.dtypes
 
     @pytest.mark.parametrize("level", [0, None])
     def test_broadcast_multiindex(self, level):

pandas/tests/frame/test_nonunique_indexes.py

@@ -10,13 +10,6 @@
 import pandas._testing as tm
 
 
-def check(result, expected=None):
-    if expected is not None:
-        tm.assert_frame_equal(result, expected)
-    result.dtypes
-    str(result)
-
-
 class TestDataFrameNonuniqueIndexes:
     def test_setattr_columns_vs_construct_with_columns(self):
         # assignment
@@ -26,7 +19,7 @@ def test_setattr_columns_vs_construct_with_columns(self):
         df = DataFrame(arr, columns=["A", "A"])
         df.columns = idx
         expected = DataFrame(arr, columns=idx)
-        check(df, expected)
+        tm.assert_frame_equal(df, expected)
 
     def test_setattr_columns_vs_construct_with_columns_datetimeindx(self):
         idx = date_range("20130101", periods=4, freq="QE-NOV")
@@ -35,7 +28,7 @@ def test_setattr_columns_vs_construct_with_columns_datetimeindx(self):
         )
         df.columns = idx
         expected = DataFrame([[1, 1, 1, 5], [1, 1, 2, 5], [2, 1, 3, 5]], columns=idx)
-        check(df, expected)
+        tm.assert_frame_equal(df, expected)
 
     def test_insert_with_duplicate_columns(self):
         # insert
@@ -48,7 +41,7 @@ def test_insert_with_duplicate_columns(self):
             [[1, 1, 1, 5, "bah"], [1, 1, 2, 5, "bah"], [2, 1, 3, 5, "bah"]],
             columns=["foo", "bar", "foo", "hello", "string"],
         )
-        check(df, expected)
+        tm.assert_frame_equal(df, expected)
         with pytest.raises(ValueError, match="Length of value"):
             df.insert(0, "AnotherColumn", range(len(df.index) - 1))
 
@@ -58,15 +51,15 @@ def test_insert_with_duplicate_columns(self):
             [[1, 1, 1, 5, "bah", 3], [1, 1, 2, 5, "bah", 3], [2, 1, 3, 5, "bah", 3]],
             columns=["foo", "bar", "foo", "hello", "string", "foo2"],
         )
-        check(df, expected)
+        tm.assert_frame_equal(df, expected)
 
         # set (non-dup)
         df["foo2"] = 4
         expected = DataFrame(
             [[1, 1, 1, 5, "bah", 4], [1, 1, 2, 5, "bah", 4], [2, 1, 3, 5, "bah", 4]],
             columns=["foo", "bar", "foo", "hello", "string", "foo2"],
         )
-        check(df, expected)
+        tm.assert_frame_equal(df, expected)
         df["foo2"] = 3
 
         # delete (non dup)
@@ -75,31 +68,31 @@ def test_insert_with_duplicate_columns(self):
             [[1, 1, 5, "bah", 3], [1, 2, 5, "bah", 3], [2, 3, 5, "bah", 3]],
             columns=["foo", "foo", "hello", "string", "foo2"],
         )
-        check(df, expected)
+        tm.assert_frame_equal(df, expected)
 
         # try to delete again (its not consolidated)
         del df["hello"]
         expected = DataFrame(
             [[1, 1, "bah", 3], [1, 2, "bah", 3], [2, 3, "bah", 3]],
             columns=["foo", "foo", "string", "foo2"],
         )
-        check(df, expected)
+        tm.assert_frame_equal(df, expected)
 
         # consolidate
         df = df._consolidate()
         expected = DataFrame(
             [[1, 1, "bah", 3], [1, 2, "bah", 3], [2, 3, "bah", 3]],
             columns=["foo", "foo", "string", "foo2"],
         )
-        check(df, expected)
+        tm.assert_frame_equal(df, expected)
 
         # insert
         df.insert(2, "new_col", 5.0)
         expected = DataFrame(
             [[1, 1, 5.0, "bah", 3], [1, 2, 5.0, "bah", 3], [2, 3, 5.0, "bah", 3]],
             columns=["foo", "foo", "new_col", "string", "foo2"],
         )
-        check(df, expected)
+        tm.assert_frame_equal(df, expected)
 
         # insert a dup
         with pytest.raises(ValueError, match="cannot insert"):
@@ -114,7 +107,7 @@ def test_insert_with_duplicate_columns(self):
             ],
             columns=["foo", "foo", "new_col", "new_col", "string", "foo2"],
         )
-        check(df, expected)
+        tm.assert_frame_equal(df, expected)
 
         # delete (dup)
         del df["foo"]
@@ -130,18 +123,17 @@ def test_dup_across_dtypes(self):
             [[1, 1, 1.0, 5], [1, 1, 2.0, 5], [2, 1, 3.0, 5]],
             columns=["foo", "bar", "foo", "hello"],
         )
-        check(df)
 
         df["foo2"] = 7.0
         expected = DataFrame(
             [[1, 1, 1.0, 5, 7.0], [1, 1, 2.0, 5, 7.0], [2, 1, 3.0, 5, 7.0]],
             columns=["foo", "bar", "foo", "hello", "foo2"],
         )
-        check(df, expected)
+        tm.assert_frame_equal(df, expected)
 
         result = df["foo"]
         expected = DataFrame([[1, 1.0], [1, 2.0], [2, 3.0]], columns=["foo", "foo"])
-        check(result, expected)
+        tm.assert_frame_equal(result, expected)
 
         # multiple replacements
         df["foo"] = "string"
@@ -153,13 +145,13 @@ def test_dup_across_dtypes(self):
             ],
             columns=["foo", "bar", "foo", "hello", "foo2"],
         )
-        check(df, expected)
+        tm.assert_frame_equal(df, expected)
 
         del df["foo"]
         expected = DataFrame(
             [[1, 5, 7.0], [1, 5, 7.0], [1, 5, 7.0]], columns=["bar", "hello", "foo2"]
         )
-        check(df, expected)
+        tm.assert_frame_equal(df, expected)
 
     def test_column_dups_indexes(self):
         # check column dups with index equal and not equal to df's index
@@ -176,7 +168,7 @@ def test_column_dups_indexes(self):
                 columns=["A", "B", "A"],
             )
             this_df["A"] = index
-            check(this_df, expected_df)
+            tm.assert_frame_equal(this_df, expected_df)
 
     def test_changing_dtypes_with_duplicate_columns(self):
         # multiple assignments that change dtypes
@@ -188,15 +180,15 @@ def test_changing_dtypes_with_duplicate_columns(self):
         expected = DataFrame(1.0, index=range(5), columns=["that", "that"])
 
         df["that"] = 1.0
-        check(df, expected)
+        tm.assert_frame_equal(df, expected)
 
         df = DataFrame(
             np.random.default_rng(2).random((5, 2)), columns=["that", "that"]
         )
         expected = DataFrame(1, index=range(5), columns=["that", "that"])
 
         df["that"] = 1
-        check(df, expected)
+        tm.assert_frame_equal(df, expected)
 
     def test_dup_columns_comparisons(self):
         # equality
@@ -231,7 +223,7 @@ def test_mixed_column_selection(self):
         )
         expected = pd.concat([dfbool["one"], dfbool["three"], dfbool["one"]], axis=1)
         result = dfbool[["one", "three", "one"]]
-        check(result, expected)
+        tm.assert_frame_equal(result, expected)
 
     def test_multi_axis_dups(self):
         # multi-axis dups
@@ -251,29 +243,26 @@ def test_multi_axis_dups(self):
         )
         z = df[["A", "C", "A"]]
         result = z.loc[["a", "c", "a"]]
-        check(result, expected)
+        tm.assert_frame_equal(result, expected)
 
     def test_columns_with_dups(self):
         # GH 3468 related
 
         # basic
         df = DataFrame([[1, 2]], columns=["a", "a"])
         df.columns = ["a", "a.1"]
-        str(df)
         expected = DataFrame([[1, 2]], columns=["a", "a.1"])
         tm.assert_frame_equal(df, expected)
 
         df = DataFrame([[1, 2, 3]], columns=["b", "a", "a"])
         df.columns = ["b", "a", "a.1"]
-        str(df)
         expected = DataFrame([[1, 2, 3]], columns=["b", "a", "a.1"])
         tm.assert_frame_equal(df, expected)
 
     def test_columns_with_dup_index(self):
         # with a dup index
         df = DataFrame([[1, 2]], columns=["a", "a"])
         df.columns = ["b", "b"]
-        str(df)
         expected = DataFrame([[1, 2]], columns=["b", "b"])
         tm.assert_frame_equal(df, expected)
 
@@ -284,7 +273,6 @@ def test_multi_dtype(self):
             columns=["a", "a", "b", "b", "d", "c", "c"],
         )
         df.columns = list("ABCDEFG")
-        str(df)
         expected = DataFrame(
             [[1, 2, 1.0, 2.0, 3.0, "foo", "bar"]], columns=list("ABCDEFG")
         )
@@ -293,7 +281,6 @@ def test_multi_dtype(self):
     def test_multi_dtype2(self):
         df = DataFrame([[1, 2, "foo", "bar"]], columns=["a", "a", "a", "a"])
         df.columns = ["a", "a.1", "a.2", "a.3"]
-        str(df)
         expected = DataFrame([[1, 2, "foo", "bar"]], columns=["a", "a.1", "a.2", "a.3"])
         tm.assert_frame_equal(df, expected)
 

pandas/tests/frame/test_repr.py

@@ -10,7 +10,9 @@
 from pandas import (
     NA,
     Categorical,
+    CategoricalIndex,
     DataFrame,
+    IntervalIndex,
     MultiIndex,
     NaT,
     PeriodIndex,
@@ -26,6 +28,21 @@
 
 
 class TestDataFrameRepr:
+    def test_repr_should_return_str(self):
+        # https://docs.python.org/3/reference/datamodel.html#object.__repr__
+        # "...The return value must be a string object."
+
+        # (str on py2.x, str (unicode) on py3)
+
+        data = [8, 5, 3, 5]
+        index1 = ["\u03c3", "\u03c4", "\u03c5", "\u03c6"]
+        cols = ["\u03c8"]
+        df = DataFrame(data, columns=cols, index=index1)
+        assert type(df.__repr__()) is str  # noqa: E721
+
+        ser = df[cols[0]]
+        assert type(ser.__repr__()) is str  # noqa: E721
+
     def test_repr_bytes_61_lines(self):
         # GH#12857
         lets = list("ACDEFGHIJKLMNOP")
@@ -291,6 +308,27 @@ def test_latex_repr(self):
         # GH 12182
         assert df._repr_latex_() is None
 
+    def test_repr_with_datetimeindex(self):
+        df = DataFrame({"A": [1, 2, 3]}, index=date_range("2000", periods=3))
+        result = repr(df)
+        expected = "            A\n2000-01-01  1\n2000-01-02  2\n2000-01-03  3"
+        assert result == expected
+
+    def test_repr_with_intervalindex(self):
+        # https://github.com/pandas-dev/pandas/pull/24134/files
+        df = DataFrame(
+            {"A": [1, 2, 3, 4]}, index=IntervalIndex.from_breaks([0, 1, 2, 3, 4])
+        )
+        result = repr(df)
+        expected = "        A\n(0, 1]  1\n(1, 2]  2\n(2, 3]  3\n(3, 4]  4"
+        assert result == expected
+
+    def test_repr_with_categorical_index(self):
+        df = DataFrame({"A": [1, 2, 3]}, index=CategoricalIndex(["a", "b", "c"]))
+        result = repr(df)
+        expected = "   A\na  1\nb  2\nc  3"
+        assert result == expected
+
     def test_repr_categorical_dates_periods(self):
         # normal DataFrame
         dt = date_range("2011-01-01 09:00", freq="h", periods=5, tz="US/Eastern")

pandas/tests/indexes/base_class/test_formats.py

@@ -8,6 +8,13 @@
 
 
 class TestIndexRendering:
+    def test_repr_is_valid_construction_code(self):
+        # for the case of Index, where the repr is traditional rather than
+        # stylized
+        idx = Index(["a", "b"])
+        res = eval(repr(idx))
+        tm.assert_index_equal(res, idx)
+
     @pytest.mark.parametrize(
         "index,expected",
         [

pandas/tests/indexes/categorical/test_category.py

@@ -257,12 +257,6 @@ def test_ensure_copied_data(self):
         result = CategoricalIndex(index.values, copy=False)
         assert result._data._codes is index._data._codes
 
-    def test_frame_repr(self):
-        df = pd.DataFrame({"A": [1, 2, 3]}, index=CategoricalIndex(["a", "b", "c"]))
-        result = repr(df)
-        expected = "   A\na  1\nb  2\nc  3"
-        assert result == expected
-
 
 class TestCategoricalIndex2:
     def test_view_i8(self):