Fix bugs

rhshadrach · rhshadrach · commit f713c4fe28b6 · 2025-11-01T12:47:59.000-04:00
diff --git a/pandas/core/apply.py b/pandas/core/apply.py
@@ -485,7 +485,7 @@ def wrap_results_list_like(
         obj = self.obj
 
         try:
-            return concat(results, keys=keys, axis=1, sort=False)  # maybebug
+            return concat(results, keys=keys, axis=1, sort=False)  # nobug
         except TypeError as err:
             # we are concatting non-NDFrame objects,
             # e.g. a list of scalars
@@ -635,10 +635,11 @@ def wrap_results_dict_like(
                 keys_to_use = ktu
 
             axis: AxisInt = 0 if isinstance(obj, ABCSeries) else 1
-            result = concat(  # maybebug
+            result = concat(  # nobug
                 results,
                 axis=axis,
                 keys=keys_to_use,
+                sort=False,
             )
         elif any(is_ndframe):
             # There is a mix of NDFrames and scalars
diff --git a/pandas/core/frame.py b/pandas/core/frame.py
@@ -6130,7 +6130,7 @@ def shift(
                     .shift(periods=period, freq=freq, axis=axis, fill_value=fill_value)
                     .add_suffix(f"{suffix}_{period}" if suffix else f"_{period}")
                 )
-            return concat(shifted_dataframes, axis=1)  # bug
+            return concat(shifted_dataframes, axis=1, sort=False)  # nobug
         elif suffix:
             raise ValueError("Cannot specify `suffix` if `periods` is an int.")
         periods = cast(int, periods)
@@ -11168,7 +11168,7 @@ def _append_internal(
 
         from pandas.core.reshape.concat import concat
 
-        result = concat(  # possible bug
+        result = concat(  # nobug
             [self, row_df],
             ignore_index=ignore_index,
         )
@@ -11401,7 +11401,7 @@ def join(
                     )
                     return res.reindex(self.index)
                 else:
-                    return concat(  # bug
+                    return concat(  # nobug
                         frames, axis=1, join=how, verify_integrity=True, sort=sort
                     )
 
diff --git a/pandas/core/generic.py b/pandas/core/generic.py
@@ -9507,7 +9507,7 @@ def compare(
 
         # error: List item 0 has incompatible type "NDFrame"; expected
         #  "Union[Series, DataFrame]"
-        diff = concat(  # bug
+        diff = concat(  # nobug - self and other must have same index/coluns
             [self, other],  # type: ignore[list-item]
             axis=axis,
             keys=result_names,
diff --git a/pandas/core/groupby/groupby.py b/pandas/core/groupby/groupby.py
@@ -1143,7 +1143,7 @@ def _concat_objects(
                 group_levels = self._grouper.levels
                 group_names = self._grouper.names
 
-                result = concat(  # maybebug
+                result = concat(
                     values,
                     axis=0,
                     keys=group_keys,
@@ -1152,10 +1152,10 @@ def _concat_objects(
                     sort=False,
                 )
             else:
-                result = concat(values, axis=0)  # maybebug
+                result = concat(values, axis=0)
 
         elif not not_indexed_same:
-            result = concat(values, axis=0)  # maybebug
+            result = concat(values, axis=0)
 
             ax = self._selected_obj.index
             if self.dropna:
@@ -1178,7 +1178,7 @@ def _concat_objects(
                 result = result.reindex(ax, axis=0)
 
         else:
-            result = concat(values, axis=0)  # maybebug
+            result = concat(values, axis=0)
 
         if self.obj.ndim == 1:
             name = self.obj.name
diff --git a/pandas/core/interchange/from_dataframe.py b/pandas/core/interchange/from_dataframe.py
@@ -144,7 +144,9 @@ def _from_dataframe(df: DataFrameXchg, allow_copy: bool = True) -> pd.DataFrame:
     elif len(pandas_dfs) == 1:
         pandas_df = pandas_dfs[0]
     else:
-        pandas_df = pd.concat(pandas_dfs, axis=0, ignore_index=True, copy=False)  # bug
+        pandas_df = pd.concat(
+            pandas_dfs, axis=0, ignore_index=True, copy=False
+        )  # nobug
 
     index_obj = df.metadata.get("pandas.index", None)
     if index_obj is not None:
diff --git a/pandas/core/reshape/melt.py b/pandas/core/reshape/melt.py
@@ -668,7 +668,7 @@ def melt_stub(df, stub: str, i, j, value_vars, sep: str):
         value_vars_flattened.extend(value_var)
         _melted.append(melt_stub(df, stub, i, j, value_var, sep))
 
-    melted = concat(_melted, axis=1)  # maybebug
+    melted = concat(_melted, axis=1)  # nobug
     id_vars = df.columns.difference(value_vars_flattened)
     new = df[id_vars]
 
diff --git a/pandas/core/series.py b/pandas/core/series.py
@@ -2994,7 +2994,7 @@ def searchsorted(  # type: ignore[override]
     def _append_internal(self, to_append: Series, ignore_index: bool = False) -> Series:
         from pandas.core.reshape.concat import concat
 
-        return concat([self, to_append], ignore_index=ignore_index)  # maybebug
+        return concat([self, to_append], ignore_index=ignore_index)  # nobug
 
     def compare(
         self,
@@ -3271,7 +3271,7 @@ def combine_first(self, other) -> Series:
         if this.dtype.kind == "M" and other.dtype.kind != "M":
             # TODO: try to match resos?
             other = to_datetime(other)
-        combined = concat([this, other])  # bug
+        combined = concat([this, other])  # nobug
         combined = combined.reindex(new_index)
         return combined.__finalize__(self, method="combine_first")
 
diff --git a/pandas/core/strings/accessor.py b/pandas/core/strings/accessor.py
@@ -659,7 +659,7 @@ def cat(
         # align if required
         if any(not data.index.equals(x.index) for x in others):
             # Need to add keys for uniqueness in case of duplicate columns
-            others = concat(  # bug
+            others = concat(  # nobug
                 others,
                 axis=1,
                 join=(join if join == "inner" else "outer"),
diff --git a/pandas/tests/apply/test_frame_apply.py b/pandas/tests/apply/test_frame_apply.py
@@ -915,6 +915,34 @@ def test_listlike_lambda(ops, by_row, expected):
     tm.assert_equal(result, expected)
 
 
+def test_listlike_datetime_index_unsorted():
+    values = [datetime(2024, 1, 1), datetime(2024, 1, 2)]
+    df = DataFrame({"a": [1, 2]}, index=[values[1], values[0]])
+    result = df.apply([lambda x: x], by_row=False)
+    expected = DataFrame(
+        [[1], [2]],
+        index=[values[1], values[0]],
+        columns=MultiIndex([["a"], ["<lambda>"]], codes=[[0], [0]]),
+    )
+    tm.assert_frame_equal(result, expected)
+
+
+def test_dictlike_datetime_index_unsorted():
+    values = [datetime(2024, 1, 1), datetime(2024, 1, 2), datetime(2024, 1, 3)]
+    df = DataFrame({"a": [1, 2], "b": [3, 4]}, index=[values[1], values[0]])
+    result = df.apply(
+        {"a": lambda x: x, "b": lambda x: x.shift(freq="D")}, by_row=False
+    )
+    expected = DataFrame(
+        {
+            "a": [1.0, 2.0, np.nan],
+            "b": [4.0, np.nan, 3.0],
+        },
+        index=[values[1], values[0], values[2]],
+    )
+    tm.assert_frame_equal(result, expected)
+
+
 @pytest.mark.parametrize(
     "ops",
     [
diff --git a/pandas/tests/frame/methods/test_shift.py b/pandas/tests/frame/methods/test_shift.py
@@ -794,3 +794,16 @@ def test_shift_invalid_fill_value_deprecation(self):
             df["a"].shift(1, fill_value=NaT)
         with tm.assert_produces_warning(Pandas4Warning, match=msg):
             df["b"].shift(1, fill_value=NaT)
+
+    def test_shift_dt_index_multiple_periods_unsorted(self):
+        values = date_range("1/1/2000", periods=4, freq="D")
+        df = DataFrame({"a": [1, 2]}, index=[values[1], values[0]])
+        result = df.shift(periods=[1, 2], freq="D")
+        expected = DataFrame(
+            {
+                "a_1": [1.0, 2.0, np.nan],
+                "a_2": [2.0, np.nan, 1.0],
+            },
+            index=[values[2], values[1], values[3]],
+        )
+        tm.assert_frame_equal(result, expected)
diff --git a/pandas/tests/reshape/merge/test_join.py b/pandas/tests/reshape/merge/test_join.py
@@ -1,3 +1,4 @@
+from datetime import datetime
 import re
 
 import numpy as np
@@ -671,6 +672,14 @@ def _check_diff_index(df_list, result, exp_index):
         with pytest.raises(ValueError, match=msg):
             df_list[0].join(df_list[1:], on="a")
 
+    def test_join_many_datetime_unsorted(self):
+        index = Index([datetime(2024, 1, 2), datetime(2024, 1, 1)])
+        df = DataFrame({"a": [1, 2]}, index=index)
+        df2 = DataFrame({"b": [1, 2]}, index=index)
+        result = df.join([df2], how="outer")
+        expected = DataFrame({"a": [1, 2], "b": [1, 2]}, index=index)
+        tm.assert_frame_equal(result, expected)
+
     def test_join_many_mixed(self):
         df = DataFrame(
             np.random.default_rng(2).standard_normal((8, 4)),
diff --git a/pandas/tests/strings/test_cat.py b/pandas/tests/strings/test_cat.py
@@ -1,3 +1,4 @@
+from datetime import datetime
 import re
 
 import numpy as np
@@ -343,6 +344,18 @@ def test_str_cat_align_mixed_inputs(join_type):
         s.str.cat([t, z], join=join_type)
 
 
+def test_str_cat_datetime_index_unsorted(join_type):
+    values = [datetime(2024, 1, 1), datetime(2024, 1, 2)]
+    s = Series(["a", "b"], index=[values[0], values[1]])
+    others = Series(["c", "d"], index=[values[1], values[0]])
+    result = s.str.cat(others, join=join_type)
+    if join_type == "right":
+        expected = Series(["bc", "ad"], index=[values[1], values[0]])
+    else:
+        expected = Series(["ad", "bc"], index=[values[0], values[1]])
+    tm.assert_series_equal(result, expected)
+
+
 def test_str_cat_all_na(index_or_series, index_or_series2):
     # GH 24044
     box = index_or_series

Original file line number	Diff line number	Diff line change
`@@ -6130,7 +6130,7 @@ def shift(`
`6130`	`6130`	`.shift(periods=period, freq=freq, axis=axis, fill_value=fill_value)`
`6131`	`6131`	`.add_suffix(f"{suffix}_{period}" if suffix else f"_{period}")`
`6132`	`6132`	`)`
`6133`		`- return concat(shifted_dataframes, axis=1) # bug`
	`6133`	`+ return concat(shifted_dataframes, axis=1, sort=False) # nobug`
`6134`	`6134`	`elif suffix:`
`6135`	`6135`	raise ValueError("Cannot specify `suffix` if `periods` is an int.")
`6136`	`6136`	`periods = cast(int, periods)`
`@@ -11168,7 +11168,7 @@ def _append_internal(`
`11168`	`11168`
`11169`	`11169`	`from pandas.core.reshape.concat import concat`
`11170`	`11170`
`11171`		`- result = concat( # possible bug`
	`11171`	`+ result = concat( # nobug`
`11172`	`11172`	`[self, row_df],`
`11173`	`11173`	`ignore_index=ignore_index,`
`11174`	`11174`	`)`
`@@ -11401,7 +11401,7 @@ def join(`
`11401`	`11401`	`)`
`11402`	`11402`	`return res.reindex(self.index)`
`11403`	`11403`	`else:`
`11404`		`- return concat( # bug`
	`11404`	`+ return concat( # nobug`
`11405`	`11405`	`frames, axis=1, join=how, verify_integrity=True, sort=sort`
`11406`	`11406`	`)`
`11407`	`11407`