From aa5589ce90f65a68c73a9562738b95b629ce0e47 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 6 Mar 2024 11:46:12 -0800
Subject: [PATCH 01/16] PERF: RangeIndex.take with 1 value return RangeIndex

---
 pandas/core/indexes/range.py              |  8 +++++++-
 pandas/tests/indexes/ranges/test_range.py | 15 +++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/pandas/core/indexes/range.py b/pandas/core/indexes/range.py
index 09d635b53c482..76068c8ee901e 100644
--- a/pandas/core/indexes/range.py
+++ b/pandas/core/indexes/range.py
@@ -1260,4 +1260,10 @@ def take(  # type: ignore[override]
             if self.start != 0:
                 taken += self.start
 
-        return self._shallow_copy(taken, name=self.name)
+        if len(taken) == 1:
+            start = taken[0]
+            return self._simple_new(
+                range(start, start + self.step, self.step), name=self.name
+            )
+        else:
+            return self._shallow_copy(taken, name=self.name)
diff --git a/pandas/tests/indexes/ranges/test_range.py b/pandas/tests/indexes/ranges/test_range.py
index 898548d1cc4dc..2b81d4794627d 100644
--- a/pandas/tests/indexes/ranges/test_range.py
+++ b/pandas/tests/indexes/ranges/test_range.py
@@ -639,6 +639,21 @@ def test_take_return_rangeindex():
     tm.assert_index_equal(result, expected, exact=True)
 
 
+@pytest.mark.parametrize(
+    "rng, exp_rng",
+    [
+        [range(5), range(3, 4)],
+        [range(0, -10, -2), range(-6, -8, -2)],
+        [range(0, 10, 2), range(6, 8, 2)],
+    ],
+)
+def test_take_1_value_returns_rangeindex(rng, exp_rng):
+    ri = RangeIndex(rng, name="foo")
+    result = ri.take([3])
+    expected = RangeIndex(exp_rng, name="foo")
+    tm.assert_index_equal(result, expected, exact=True)
+
+
 def test_append_one_nonempty_preserve_step():
     expected = RangeIndex(0, -1, -1)
     result = RangeIndex(0).append([expected])

From 47af1ce9abaa3e112a995d10ecb76ae48ef4bbf5 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 6 Mar 2024 11:47:17 -0800
Subject: [PATCH 02/16] add issue number

---
 doc/source/whatsnew/v3.0.0.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/source/whatsnew/v3.0.0.rst b/doc/source/whatsnew/v3.0.0.rst
index 7802ef4798659..8941af2a5b463 100644
--- a/doc/source/whatsnew/v3.0.0.rst
+++ b/doc/source/whatsnew/v3.0.0.rst
@@ -258,7 +258,7 @@ Performance improvements
 - Performance improvement in :meth:`RangeIndex.append` when appending the same index (:issue:`57252`)
 - Performance improvement in :meth:`RangeIndex.join` returning a :class:`RangeIndex` instead of a :class:`Index` when possible. (:issue:`57651`)
 - Performance improvement in :meth:`RangeIndex.reindex` returning a :class:`RangeIndex` instead of a :class:`Index` when possible. (:issue:`57647`)
-- Performance improvement in :meth:`RangeIndex.take` returning a :class:`RangeIndex` instead of a :class:`Index` when possible. (:issue:`57445`)
+- Performance improvement in :meth:`RangeIndex.take` returning a :class:`RangeIndex` instead of a :class:`Index` when possible. (:issue:`57445`, :issue:`57752`)
 - Performance improvement in ``DataFrameGroupBy.__len__`` and ``SeriesGroupBy.__len__`` (:issue:`57595`)
 - Performance improvement in indexing operations for string dtypes (:issue:`56997`)
 

From e7e0fcba0cf6fb2f94ceb5d9b8ae8ec4b5131f39 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 6 Mar 2024 13:08:26 -0800
Subject: [PATCH 03/16] Move to _shallow_copy, support empty join as well

---
 doc/source/whatsnew/v3.0.0.rst            |  4 +--
 pandas/core/indexes/base.py               |  1 -
 pandas/core/indexes/range.py              | 44 +++++++++++++++--------
 pandas/tests/indexes/ranges/test_join.py  |  8 ++++-
 pandas/tests/indexes/ranges/test_range.py | 20 +++++++++++
 5 files changed, 58 insertions(+), 19 deletions(-)

diff --git a/doc/source/whatsnew/v3.0.0.rst b/doc/source/whatsnew/v3.0.0.rst
index 8941af2a5b463..70fe03000290b 100644
--- a/doc/source/whatsnew/v3.0.0.rst
+++ b/doc/source/whatsnew/v3.0.0.rst
@@ -256,8 +256,8 @@ Performance improvements
 - Performance improvement in :meth:`MultiIndex.equals` for equal length indexes (:issue:`56990`)
 - Performance improvement in :meth:`RangeIndex.__getitem__` with a boolean mask returning a :class:`RangeIndex` instead of a :class:`Index` when possible. (:issue:`57588`)
 - Performance improvement in :meth:`RangeIndex.append` when appending the same index (:issue:`57252`)
-- Performance improvement in :meth:`RangeIndex.join` returning a :class:`RangeIndex` instead of a :class:`Index` when possible. (:issue:`57651`)
-- Performance improvement in :meth:`RangeIndex.reindex` returning a :class:`RangeIndex` instead of a :class:`Index` when possible. (:issue:`57647`)
+- Performance improvement in :meth:`RangeIndex.join` returning a :class:`RangeIndex` instead of a :class:`Index` when possible. (:issue:`57651`, :issue:`57752`)
+- Performance improvement in :meth:`RangeIndex.reindex` returning a :class:`RangeIndex` instead of a :class:`Index` when possible. (:issue:`57647`, :issue:`57752`)
 - Performance improvement in :meth:`RangeIndex.take` returning a :class:`RangeIndex` instead of a :class:`Index` when possible. (:issue:`57445`, :issue:`57752`)
 - Performance improvement in ``DataFrameGroupBy.__len__`` and ``SeriesGroupBy.__len__`` (:issue:`57595`)
 - Performance improvement in indexing operations for string dtypes (:issue:`56997`)
diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index c72c5fa019bd7..4e5cc986b7325 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -4241,7 +4241,6 @@ def join(
 
         return self._join_via_get_indexer(other, how, sort)
 
-    @final
     def _join_empty(
         self, other: Index, how: JoinHow, sort: bool
     ) -> tuple[Index, npt.NDArray[np.intp] | None, npt.NDArray[np.intp] | None]:
diff --git a/pandas/core/indexes/range.py b/pandas/core/indexes/range.py
index 76068c8ee901e..573bd6cf14bcb 100644
--- a/pandas/core/indexes/range.py
+++ b/pandas/core/indexes/range.py
@@ -472,18 +472,31 @@ def _shallow_copy(self, values, name: Hashable = no_default):
 
         if values.dtype.kind == "f":
             return Index(values, name=name, dtype=np.float64)
-        if values.dtype.kind == "i" and values.ndim == 1 and len(values) > 1:
+        if values.dtype.kind == "i" and values.ndim == 1:
             # GH 46675 & 43885: If values is equally spaced, return a
             # more memory-compact RangeIndex instead of Index with 64-bit dtype
+            if len(values) == 0:
+                return type(self)._simple_new(_empty_range, name=self.name)
+            elif len(values) == 1:
+                start = values[0]
+                new_range = range(start, start + self.step, self.step)
+                return type(self)._simple_new(new_range, name=self.name)
             diff = values[1] - values[0]
             if not missing.isna(diff) and diff != 0:
-                maybe_range_indexer, remainder = np.divmod(values - values[0], diff)
-                if (
-                    lib.is_range_indexer(maybe_range_indexer, len(maybe_range_indexer))
-                    and not remainder.any()
-                ):
+                if len(values) == 2:
+                    # Can skip is_range_indexer check
                     new_range = range(values[0], values[-1] + diff, diff)
-                    return type(self)._simple_new(new_range, name=name)
+                    return type(self)._simple_new(new_range, name=self.name)
+                else:
+                    maybe_range_indexer, remainder = np.divmod(values - values[0], diff)
+                    if (
+                        lib.is_range_indexer(
+                            maybe_range_indexer, len(maybe_range_indexer)
+                        )
+                        and not remainder.any()
+                    ):
+                        new_range = range(values[0], values[-1] + diff, diff)
+                        return type(self)._simple_new(new_range, name=name)
         return self._constructor._simple_new(values, name=name)
 
     def _view(self) -> Self:
@@ -897,12 +910,19 @@ def symmetric_difference(
             result = result.rename(result_name)
         return result
 
+    def _join_empty(
+        self, other: Index, how: JoinHow, sort: bool
+    ) -> tuple[Index, npt.NDArray[np.intp] | None, npt.NDArray[np.intp] | None]:
+        if other.dtype.kind == "i":
+            other = self._shallow_copy(other._values, name=other.name)
+        return super()._join_empty(other, how=how, sort=sort)
+
     def _join_monotonic(
         self, other: Index, how: JoinHow = "left"
     ) -> tuple[Index, npt.NDArray[np.intp] | None, npt.NDArray[np.intp] | None]:
         # This currently only gets called for the monotonic increasing case
         if not isinstance(other, type(self)):
-            maybe_ri = self._shallow_copy(other._values)
+            maybe_ri = self._shallow_copy(other._values, name=other.name)
             if not isinstance(maybe_ri, type(self)):
                 return super()._join_monotonic(other, how=how)
             other = maybe_ri
@@ -1260,10 +1280,4 @@ def take(  # type: ignore[override]
             if self.start != 0:
                 taken += self.start
 
-        if len(taken) == 1:
-            start = taken[0]
-            return self._simple_new(
-                range(start, start + self.step, self.step), name=self.name
-            )
-        else:
-            return self._shallow_copy(taken, name=self.name)
+        return self._shallow_copy(taken, name=self.name)
diff --git a/pandas/tests/indexes/ranges/test_join.py b/pandas/tests/indexes/ranges/test_join.py
index ca3af607c0a38..09db30b1d4c51 100644
--- a/pandas/tests/indexes/ranges/test_join.py
+++ b/pandas/tests/indexes/ranges/test_join.py
@@ -207,9 +207,15 @@ def test_join_self(self, join_type):
             [-1, -1, 0, 1],
             "outer",
         ],
+        [RangeIndex(2), RangeIndex(0), RangeIndex(2), None, [-1, -1], "left"],
+        [RangeIndex(2), RangeIndex(0), RangeIndex(0), [], None, "right"],
+        [RangeIndex(2), RangeIndex(0), RangeIndex(0), [], None, "inner"],
+        [RangeIndex(2), RangeIndex(0), RangeIndex(2), None, [-1, -1], "outer"],
     ],
 )
-@pytest.mark.parametrize("right_type", [RangeIndex, lambda x: Index(list(x))])
+@pytest.mark.parametrize(
+    "right_type", [RangeIndex, lambda x: Index(list(x), dtype=x.dtype)]
+)
 def test_join_preserves_rangeindex(
     left, right, expected, expected_lidx, expected_ridx, how, right_type
 ):
diff --git a/pandas/tests/indexes/ranges/test_range.py b/pandas/tests/indexes/ranges/test_range.py
index 2b81d4794627d..528315078277d 100644
--- a/pandas/tests/indexes/ranges/test_range.py
+++ b/pandas/tests/indexes/ranges/test_range.py
@@ -608,6 +608,26 @@ def test_range_index_rsub_by_const(self):
         tm.assert_index_equal(result, expected)
 
 
+def test_reindex_1_value_returns_rangeindex():
+    ri = RangeIndex(0, 10, 2, name="foo")
+    result, result_indexer = ri.reindex([2])
+    expected = RangeIndex(2, 4, 2, name="foo")
+    tm.assert_index_equal(result, expected, exact=True)
+
+    expected_indexer = np.array([1], dtype=np.intp)
+    tm.assert_numpy_array_equal(result_indexer, expected_indexer)
+
+
+def test_reindex_empty_returns_rangeindex():
+    ri = RangeIndex(0, 10, 2, name="foo")
+    result, result_indexer = ri.reindex([])
+    expected = RangeIndex(0, 0, 2, name="foo")
+    tm.assert_index_equal(result, expected, exact=True)
+
+    expected_indexer = np.array([], dtype=np.intp)
+    tm.assert_numpy_array_equal(result_indexer, expected_indexer)
+
+
 def test_reindex_returns_rangeindex():
     ri = RangeIndex(2, name="foo")
     result, result_indexer = ri.reindex([1, 2, 3])

From 67f19987a86d11d046e4d7f63d58caca3b217a42 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 6 Mar 2024 13:09:59 -0800
Subject: [PATCH 04/16] Fix self.name

---
 pandas/core/indexes/range.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pandas/core/indexes/range.py b/pandas/core/indexes/range.py
index 573bd6cf14bcb..4fa075d10c9e0 100644
--- a/pandas/core/indexes/range.py
+++ b/pandas/core/indexes/range.py
@@ -476,17 +476,17 @@ def _shallow_copy(self, values, name: Hashable = no_default):
             # GH 46675 & 43885: If values is equally spaced, return a
             # more memory-compact RangeIndex instead of Index with 64-bit dtype
             if len(values) == 0:
-                return type(self)._simple_new(_empty_range, name=self.name)
+                return type(self)._simple_new(_empty_range, name=name)
             elif len(values) == 1:
                 start = values[0]
                 new_range = range(start, start + self.step, self.step)
-                return type(self)._simple_new(new_range, name=self.name)
+                return type(self)._simple_new(new_range, name=name)
             diff = values[1] - values[0]
             if not missing.isna(diff) and diff != 0:
                 if len(values) == 2:
                     # Can skip is_range_indexer check
                     new_range = range(values[0], values[-1] + diff, diff)
-                    return type(self)._simple_new(new_range, name=self.name)
+                    return type(self)._simple_new(new_range, name=name)
                 else:
                     maybe_range_indexer, remainder = np.divmod(values - values[0], diff)
                     if (

From 2cc41fc25fc245cf4cb96716685b5e19a770f719 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 6 Mar 2024 13:55:15 -0800
Subject: [PATCH 05/16] FIx error message

---
 pandas/tests/indexing/test_loc.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/tests/indexing/test_loc.py b/pandas/tests/indexing/test_loc.py
index 9c33d15c01cd6..61a3a7fbe87f2 100644
--- a/pandas/tests/indexing/test_loc.py
+++ b/pandas/tests/indexing/test_loc.py
@@ -508,7 +508,7 @@ def test_loc_getitem_list_with_fail(self):
 
         s.loc[[2]]
 
-        msg = f"\"None of [Index([3], dtype='{np.dtype(int)}')] are in the [index]"
+        msg = "None of [RangeIndex(start=3, stop=4, step=1)] are in the [index]"
         with pytest.raises(KeyError, match=re.escape(msg)):
             s.loc[[3]]
 

From c7da6acc720613e6494868ea0e87a40db4d6e280 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 6 Mar 2024 15:41:44 -0800
Subject: [PATCH 06/16] Fix hdf test

---
 pandas/tests/io/pytables/test_append.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pandas/tests/io/pytables/test_append.py b/pandas/tests/io/pytables/test_append.py
index 529d6d789596f..72abbcec63357 100644
--- a/pandas/tests/io/pytables/test_append.py
+++ b/pandas/tests/io/pytables/test_append.py
@@ -967,6 +967,8 @@ def test_append_to_multiple_min_itemsize(setup_path):
         }
     )
     expected = df.iloc[[0]]
+    # Reading/writing RangeIndex info is not supported yet
+    expected.index = Index(list(range(len(expected.index))))
 
     with ensure_clean_store(setup_path) as store:
         store.append_to_multiple(

From 90ff39cb278c6d922a2d4a207fe4348efb82d0e4 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Fri, 8 Mar 2024 15:13:25 -0800
Subject: [PATCH 07/16] PERF: Allow ensure_index_from_sequence to return
 RangeIndex

---
 pandas/core/indexes/base.py       | 38 ++++++++++++++++++++++++++++++-
 pandas/core/indexes/range.py      | 24 ++++---------------
 pandas/tests/indexes/test_base.py |  8 ++++---
 3 files changed, 46 insertions(+), 24 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 4e5cc986b7325..cb26bd3ea2565 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -7167,6 +7167,41 @@ def shape(self) -> Shape:
         return (len(self),)
 
 
+def maybe_sequence_to_range(sequence) -> Any | range:
+    """
+    Convert a 1D sequence to a range if possible.
+
+    Returns the input if not possible.
+
+    Parameters
+    ----------
+    sequence : 1D sequence
+    names : sequence of str
+
+    Returns
+    -------
+    Any : input or range
+    """
+    np_sequence = np.asarray(sequence)
+    if np_sequence.dtype.kind != "i" or len(sequence) == 1:
+        return sequence
+    elif len(sequence) == 0:
+        return range(0)
+    diff = np_sequence[1] - np_sequence[0]
+    if isna(diff) or diff == 0:
+        return sequence
+    elif len(sequence) == 2:
+        return range(sequence[0], sequence[1] + diff, diff)
+    maybe_range_indexer, remainder = np.divmod(np_sequence - np_sequence[0], diff)
+    if (
+        lib.is_range_indexer(maybe_range_indexer, len(maybe_range_indexer))
+        and not remainder.any()
+    ):
+        return range(sequence[0], sequence[-1] + diff, diff)
+    else:
+        return sequence
+
+
 def ensure_index_from_sequences(sequences, names=None) -> Index:
     """
     Construct an index from sequences of data.
@@ -7202,8 +7237,9 @@ def ensure_index_from_sequences(sequences, names=None) -> Index:
     if len(sequences) == 1:
         if names is not None:
             names = names[0]
-        return Index(sequences[0], name=names)
+        return Index(maybe_sequence_to_range(sequences[0]), name=names)
     else:
+        # TODO: Apply maybe_sequence_to_range to sequences?
         return MultiIndex.from_arrays(sequences, names=names)
 
 
diff --git a/pandas/core/indexes/range.py b/pandas/core/indexes/range.py
index fcb47de2b3c0d..07a7c49b411c0 100644
--- a/pandas/core/indexes/range.py
+++ b/pandas/core/indexes/range.py
@@ -29,7 +29,6 @@
     doc,
 )
 
-from pandas.core.dtypes import missing
 from pandas.core.dtypes.base import ExtensionDtype
 from pandas.core.dtypes.common import (
     ensure_platform_int,
@@ -475,28 +474,13 @@ def _shallow_copy(self, values, name: Hashable = no_default):
         if values.dtype.kind == "i" and values.ndim == 1:
             # GH 46675 & 43885: If values is equally spaced, return a
             # more memory-compact RangeIndex instead of Index with 64-bit dtype
-            if len(values) == 0:
-                return type(self)._simple_new(_empty_range, name=name)
-            elif len(values) == 1:
+            if len(values) == 1:
                 start = values[0]
                 new_range = range(start, start + self.step, self.step)
                 return type(self)._simple_new(new_range, name=name)
-            diff = values[1] - values[0]
-            if not missing.isna(diff) and diff != 0:
-                if len(values) == 2:
-                    # Can skip is_range_indexer check
-                    new_range = range(values[0], values[-1] + diff, diff)
-                    return type(self)._simple_new(new_range, name=name)
-                else:
-                    maybe_range_indexer, remainder = np.divmod(values - values[0], diff)
-                    if (
-                        lib.is_range_indexer(
-                            maybe_range_indexer, len(maybe_range_indexer)
-                        )
-                        and not remainder.any()
-                    ):
-                        new_range = range(values[0], values[-1] + diff, diff)
-                        return type(self)._simple_new(new_range, name=name)
+            maybe_range = ibase.maybe_sequence_to_range(values)
+            if isinstance(maybe_range, range):
+                return type(self)._simple_new(maybe_range, name=name)
         return self._constructor._simple_new(values, name=name)
 
     def _view(self) -> Self:
diff --git a/pandas/tests/indexes/test_base.py b/pandas/tests/indexes/test_base.py
index 4c703c3af944b..beee14197bfb8 100644
--- a/pandas/tests/indexes/test_base.py
+++ b/pandas/tests/indexes/test_base.py
@@ -1514,8 +1514,10 @@ class TestIndexUtils:
     @pytest.mark.parametrize(
         "data, names, expected",
         [
-            ([[1, 2, 3]], None, Index([1, 2, 3])),
-            ([[1, 2, 3]], ["name"], Index([1, 2, 3], name="name")),
+            ([[1, 2, 4]], None, Index([1, 2, 4])),
+            ([[1, 2, 4]], ["name"], Index([1, 2, 4], name="name")),
+            ([[1, 2, 3]], None, RangeIndex(1, 4)),
+            ([[1, 2, 3]], ["name"], RangeIndex(1, 4, name="name")),
             (
                 [["a", "a"], ["c", "d"]],
                 None,
@@ -1530,7 +1532,7 @@ class TestIndexUtils:
     )
     def test_ensure_index_from_sequences(self, data, names, expected):
         result = ensure_index_from_sequences(data, names)
-        tm.assert_index_equal(result, expected)
+        tm.assert_index_equal(result, expected, exact=True)
 
     def test_ensure_index_mixed_closed_intervals(self):
         # GH27172

From 66d3456aa7d677cea42affadcb54ab987e62e66a Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Fri, 8 Mar 2024 16:01:13 -0800
Subject: [PATCH 08/16] Ignore Index and Series objects

---
 pandas/core/indexes/base.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index cb26bd3ea2565..1c2210cd74a77 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -7182,6 +7182,8 @@ def maybe_sequence_to_range(sequence) -> Any | range:
     -------
     Any : input or range
     """
+    if hasattr(sequence, "dtype") and not isinstance(sequence, np.ndarray):
+        return sequence
     np_sequence = np.asarray(sequence)
     if np_sequence.dtype.kind != "i" or len(sequence) == 1:
         return sequence

From 7e6fcea924525c39916cf9266c05d20961c4f5a8 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Fri, 8 Mar 2024 16:52:17 -0800
Subject: [PATCH 09/16] Fix doctest

---
 pandas/core/indexes/base.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 98a8ebfd7dd08..8e3b35b9d67d2 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -7210,8 +7210,8 @@ def ensure_index_from_sequences(sequences, names=None) -> Index:
 
     Examples
     --------
-    >>> ensure_index_from_sequences([[1, 2, 3]], names=["name"])
-    Index([1, 2, 3], dtype='int64', name='name')
+    >>> ensure_index_from_sequences([[1, 2, 4]], names=["name"])
+    Index([1, 2, 4], dtype='int64', name='name')
 
     >>> ensure_index_from_sequences([["a", "a"], ["a", "b"]], names=["L1", "L2"])
     MultiIndex([('a', 'a'),

From b5144f46b2ad2d5d8d82abf645e641d0e2721ad7 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Tue, 12 Mar 2024 17:23:49 -0700
Subject: [PATCH 10/16] More specific check

---
 pandas/core/indexes/base.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 8e3b35b9d67d2..2d0d33c627772 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -7170,7 +7170,8 @@ def maybe_sequence_to_range(sequence) -> Any | range:
     -------
     Any : input or range
     """
-    if hasattr(sequence, "dtype") and not isinstance(sequence, np.ndarray):
+    dtype = getattr(sequence, "dtype", None)
+    if not (dtype is None or isinstance(dtype, np.dtype)):
         return sequence
     np_sequence = np.asarray(sequence)
     if np_sequence.dtype.kind != "i" or len(sequence) == 1:

From 08da810dfa748ac3d5b1021f84a5c5fb3d833794 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 13 Mar 2024 10:38:47 -0700
Subject: [PATCH 11/16] Only allow int64, fix indexing

---
 pandas/core/indexes/base.py   | 8 ++++++--
 pandas/tests/io/test_stata.py | 1 -
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 2d0d33c627772..beebfc70a88c1 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -7174,7 +7174,11 @@ def maybe_sequence_to_range(sequence) -> Any | range:
     if not (dtype is None or isinstance(dtype, np.dtype)):
         return sequence
     np_sequence = np.asarray(sequence)
-    if np_sequence.dtype.kind != "i" or len(sequence) == 1:
+    if (
+        not (np_sequence.dtype.kind == "i" and np_sequence.dtype.alignment == 8)
+        or len(sequence) == 1
+    ):
+        # TODO: Coerce non int64 to ranges?
         return sequence
     elif len(sequence) == 0:
         return range(0)
@@ -7188,7 +7192,7 @@ def maybe_sequence_to_range(sequence) -> Any | range:
         lib.is_range_indexer(maybe_range_indexer, len(maybe_range_indexer))
         and not remainder.any()
     ):
-        return range(sequence[0], sequence[-1] + diff, diff)
+        return range(sequence[0], sequence[len(sequence) - 1] + diff, diff)
     else:
         return sequence
 
diff --git a/pandas/tests/io/test_stata.py b/pandas/tests/io/test_stata.py
index 9078ca865042d..4a1030e733126 100644
--- a/pandas/tests/io/test_stata.py
+++ b/pandas/tests/io/test_stata.py
@@ -2049,7 +2049,6 @@ def test_compression(compression, version, use_dict, infer, compression_to_exten
         reread = read_stata(fp, index_col="index")
 
     expected = df
-    expected.index = expected.index.astype(np.int32)
     tm.assert_frame_equal(reread, expected)
 
 

From b7e5dc1f5f53a675a35524e9235a40c90e8e48a4 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 13 Mar 2024 13:07:05 -0700
Subject: [PATCH 12/16] use Index

---
 pandas/core/indexes/base.py | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 520feeabae9df..9f866ac0a1903 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -7172,26 +7172,26 @@ def maybe_sequence_to_range(sequence) -> Any | range:
     dtype = getattr(sequence, "dtype", None)
     if not (dtype is None or isinstance(dtype, np.dtype)):
         return sequence
-    np_sequence = np.asarray(sequence)
+    idx_sequence = Index(sequence)
     if (
-        not (np_sequence.dtype.kind == "i" and np_sequence.dtype.alignment == 8)
+        not (idx_sequence.dtype.kind == "i" and idx_sequence.dtype.alignment == 8)
         or len(sequence) == 1
     ):
         # TODO: Coerce non int64 to ranges?
         return sequence
-    elif len(sequence) == 0:
+    elif len(idx_sequence) == 0:
         return range(0)
-    diff = np_sequence[1] - np_sequence[0]
+    diff = idx_sequence[1] - idx_sequence[0]
     if isna(diff) or diff == 0:
         return sequence
-    elif len(sequence) == 2:
-        return range(sequence[0], sequence[1] + diff, diff)
-    maybe_range_indexer, remainder = np.divmod(np_sequence - np_sequence[0], diff)
+    elif len(idx_sequence) == 2:
+        return range(idx_sequence[0], idx_sequence[1] + diff, diff)
+    maybe_range_indexer, remainder = np.divmod(idx_sequence - idx_sequence[0], diff)
     if (
         lib.is_range_indexer(maybe_range_indexer, len(maybe_range_indexer))
         and not remainder.any()
     ):
-        return range(sequence[0], sequence[len(sequence) - 1] + diff, diff)
+        return range(idx_sequence[0], idx_sequence[-1] + diff, diff)
     else:
         return sequence
 

From f0592c5e4a8c439f6baebcb74abe7b08eea327e2 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 13 Mar 2024 14:52:24 -0700
Subject: [PATCH 13/16] Use np_values

---
 pandas/core/indexes/base.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 9f866ac0a1903..b602328898c78 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -7186,12 +7186,13 @@ def maybe_sequence_to_range(sequence) -> Any | range:
         return sequence
     elif len(idx_sequence) == 2:
         return range(idx_sequence[0], idx_sequence[1] + diff, diff)
-    maybe_range_indexer, remainder = np.divmod(idx_sequence - idx_sequence[0], diff)
+    np_values = idx_sequence._data
+    maybe_range_indexer, remainder = np.divmod(np_values - np_values[0], diff)
     if (
         lib.is_range_indexer(maybe_range_indexer, len(maybe_range_indexer))
         and not remainder.any()
     ):
-        return range(idx_sequence[0], idx_sequence[-1] + diff, diff)
+        return range(np_values[0], np_values[-1] + diff, diff)
     else:
         return sequence
 

From 33fa1f4a432d8fde0ef60a75783b3cff9438da92 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 13 Mar 2024 16:33:17 -0700
Subject: [PATCH 14/16] Add back int32

---
 pandas/tests/io/test_stata.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pandas/tests/io/test_stata.py b/pandas/tests/io/test_stata.py
index 4a1030e733126..9078ca865042d 100644
--- a/pandas/tests/io/test_stata.py
+++ b/pandas/tests/io/test_stata.py
@@ -2049,6 +2049,7 @@ def test_compression(compression, version, use_dict, infer, compression_to_exten
         reread = read_stata(fp, index_col="index")
 
     expected = df
+    expected.index = expected.index.astype(np.int32)
     tm.assert_frame_equal(reread, expected)
 
 

From 5fb9516bc8f77f868e24fd53f9e2a2d148f26453 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Thu, 14 Mar 2024 11:53:22 -0700
Subject: [PATCH 15/16] Ignore Series and Index objects

---
 pandas/core/indexes/base.py | 28 +++++++++++-----------------
 1 file changed, 11 insertions(+), 17 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index b602328898c78..d8e3811bf9804 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -7156,7 +7156,7 @@ def shape(self) -> Shape:
 
 def maybe_sequence_to_range(sequence) -> Any | range:
     """
-    Convert a 1D sequence to a range if possible.
+    Convert a 1D, non-pandas sequence to a range if possible.
 
     Returns the input if not possible.
 
@@ -7169,30 +7169,24 @@ def maybe_sequence_to_range(sequence) -> Any | range:
     -------
     Any : input or range
     """
-    dtype = getattr(sequence, "dtype", None)
-    if not (dtype is None or isinstance(dtype, np.dtype)):
+    if isinstance(sequence, (ABCSeries, Index)):
         return sequence
-    idx_sequence = Index(sequence)
-    if (
-        not (idx_sequence.dtype.kind == "i" and idx_sequence.dtype.alignment == 8)
-        or len(sequence) == 1
-    ):
-        # TODO: Coerce non int64 to ranges?
+    np_sequence = np.asarray(sequence)
+    if np_sequence.dtype.kind == "i" or len(np_sequence) == 1:
         return sequence
-    elif len(idx_sequence) == 0:
+    elif len(np_sequence) == 0:
         return range(0)
-    diff = idx_sequence[1] - idx_sequence[0]
-    if isna(diff) or diff == 0:
+    diff = np_sequence[1] - np_sequence[0]
+    if diff == 0:
         return sequence
-    elif len(idx_sequence) == 2:
-        return range(idx_sequence[0], idx_sequence[1] + diff, diff)
-    np_values = idx_sequence._data
-    maybe_range_indexer, remainder = np.divmod(np_values - np_values[0], diff)
+    elif len(np_sequence) == 2:
+        return range(np_sequence[0], np_sequence[1] + diff, diff)
+    maybe_range_indexer, remainder = np.divmod(np_sequence - np_sequence[0], diff)
     if (
         lib.is_range_indexer(maybe_range_indexer, len(maybe_range_indexer))
         and not remainder.any()
     ):
-        return range(np_values[0], np_values[-1] + diff, diff)
+        return range(np_sequence[0], np_sequence[-1] + diff, diff)
     else:
         return sequence
 

From 4e7cf98ced86dc3b7e77ef91f8b7da01757f075c Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Thu, 14 Mar 2024 13:50:51 -0700
Subject: [PATCH 16/16] Wrong condition

---
 pandas/core/indexes/base.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index d8e3811bf9804..3c01778e05f3d 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -7172,7 +7172,7 @@ def maybe_sequence_to_range(sequence) -> Any | range:
     if isinstance(sequence, (ABCSeries, Index)):
         return sequence
     np_sequence = np.asarray(sequence)
-    if np_sequence.dtype.kind == "i" or len(np_sequence) == 1:
+    if np_sequence.dtype.kind != "i" or len(np_sequence) == 1:
         return sequence
     elif len(np_sequence) == 0:
         return range(0)