From 6d6868327b980e0fe5186d63367da23f885850f0 Mon Sep 17 00:00:00 2001
From: Rohan Jain <rohanjain@microsoft.com>
Date: Mon, 8 Jan 2024 20:34:52 -0500
Subject: [PATCH 01/14] fix find

---
 pandas/core/arrays/arrow/array.py    | 30 +++++++++++++++++-----------
 pandas/tests/extension/test_arrow.py | 20 ++++++++++---------
 2 files changed, 29 insertions(+), 21 deletions(-)

diff --git a/pandas/core/arrays/arrow/array.py b/pandas/core/arrays/arrow/array.py
index 23b5c6385c13b..f7a1ca702891a 100644
--- a/pandas/core/arrays/arrow/array.py
+++ b/pandas/core/arrays/arrow/array.py
@@ -2328,19 +2328,25 @@ def _str_fullmatch(
         return self._str_match(pat, case, flags, na)
 
     def _str_find(self, sub: str, start: int = 0, end: int | None = None) -> Self:
-        if start != 0 and end is not None:
-            slices = pc.utf8_slice_codeunits(self._pa_array, start, stop=end)
-            result = pc.find_substring(slices, sub)
-            not_found = pc.equal(result, -1)
-            start_offset = max(0, start)
-            offset_result = pc.add(result, start_offset)
-            result = pc.if_else(not_found, result, offset_result)
-        elif start == 0 and end is None:
-            slices = self._pa_array
-            result = pc.find_substring(slices, sub)
+        if (start == 0 or start is None) and end is None:
+            result = pc.find_substring(self._pa_array, sub)
         else:
-            raise NotImplementedError(
-                f"find not implemented with {sub=}, {start=}, {end=}"
+            result = pc.find_substring(self._pa_array, sub)
+            length = pc.utf8_length(self._pa_array)
+            if start is None:
+                start = pa.scalar(0, result.type)
+            elif start < 0:
+                start = pc.add(start, length)
+            if end is None:
+                end = length
+            elif end < 0:
+                end = pc.add(end, length)
+            found = pc.not_equal(pa.scalar(-1, type=result.type), result)
+            found_in_bounds = pc.and_(
+                pc.greater_equal(result, start), pc.less(result, end)
+            )
+            result = pc.if_else(
+                pc.and_(found, found_in_bounds), result, pa.scalar(-1, type=result.type)
             )
         return type(self)(result)
 
diff --git a/pandas/tests/extension/test_arrow.py b/pandas/tests/extension/test_arrow.py
index 8d0bb85b2a01f..913a0f1c9a29e 100644
--- a/pandas/tests/extension/test_arrow.py
+++ b/pandas/tests/extension/test_arrow.py
@@ -1919,13 +1919,13 @@ def test_str_fullmatch(pat, case, na, exp):
 
 
 @pytest.mark.parametrize(
-    "sub, start, end, exp, exp_typ",
-    [["ab", 0, None, [0, None], pa.int32()], ["bc", 1, 3, [1, None], pa.int64()]],
+    "sub, start, end, exp",
+    [["ab", 0, None, [0, None]], ["bc", 1, 3, [1, None]], ["ab", 1, None, [-1, None]]],
 )
-def test_str_find(sub, start, end, exp, exp_typ):
+def test_str_find(sub, start, end, exp):
     ser = pd.Series(["abc", None], dtype=ArrowDtype(pa.string()))
     result = ser.str.find(sub, start=start, end=end)
-    expected = pd.Series(exp, dtype=ArrowDtype(exp_typ))
+    expected = pd.Series(exp, dtype=ArrowDtype(pa.int32()))
     tm.assert_series_equal(result, expected)
 
 
@@ -1933,14 +1933,16 @@ def test_str_find_negative_start():
     # GH 56411
     ser = pd.Series(["abc", None], dtype=ArrowDtype(pa.string()))
     result = ser.str.find(sub="b", start=-1000, end=3)
-    expected = pd.Series([1, None], dtype=ArrowDtype(pa.int64()))
+    expected = pd.Series([1, None], dtype=ArrowDtype(pa.int32()))
     tm.assert_series_equal(result, expected)
 
 
-def test_str_find_notimplemented():
-    ser = pd.Series(["abc", None], dtype=ArrowDtype(pa.string()))
-    with pytest.raises(NotImplementedError, match="find not implemented"):
-        ser.str.find("ab", start=1)
+def test_str_find_negative_start_negative_end():
+    # GH 56411
+    ser = pd.Series(["abcdefg", None], dtype=ArrowDtype(pa.string()))
+    result = ser.str.find(sub="d", start=-6, end=-3)
+    expected = pd.Series([3, None], dtype=ArrowDtype(pa.int32()))
+    tm.assert_series_equal(result, expected)
 
 
 @pytest.mark.parametrize(

From 533f54c7b960652764ad968f87fb4f372a7b7249 Mon Sep 17 00:00:00 2001
From: Rohan Jain <rohanjain@microsoft.com>
Date: Mon, 8 Jan 2024 21:12:13 -0500
Subject: [PATCH 02/14] gh reference

---
 doc/source/whatsnew/v2.2.0.rst       |  1 +
 pandas/core/arrays/arrow/array.py    | 27 ++++++++++++---------------
 pandas/tests/extension/test_arrow.py | 19 ++++++++++++-------
 3 files changed, 25 insertions(+), 22 deletions(-)

diff --git a/doc/source/whatsnew/v2.2.0.rst b/doc/source/whatsnew/v2.2.0.rst
index 0b04a1d313a6d..4a83f8003739a 100644
--- a/doc/source/whatsnew/v2.2.0.rst
+++ b/doc/source/whatsnew/v2.2.0.rst
@@ -803,6 +803,7 @@ Strings
 - Bug in :meth:`DataFrame.reindex` not matching :class:`Index` with ``string[pyarrow_numpy]`` dtype (:issue:`56106`)
 - Bug in :meth:`Index.str.cat` always casting result to object dtype (:issue:`56157`)
 - Bug in :meth:`Series.__mul__` for :class:`ArrowDtype` with ``pyarrow.string`` dtype and ``string[pyarrow]`` for the pyarrow backend (:issue:`51970`)
+- Bug in :meth:`Series.str.find` when ``start < 0`` and ``end < 0`` for :class:`ArrowDtype` with ``pyarrow.string`` (:issue:`56791`)
 - Bug in :meth:`Series.str.find` when ``start < 0`` for :class:`ArrowDtype` with ``pyarrow.string`` (:issue:`56411`)
 - Bug in :meth:`Series.str.replace` when ``n < 0`` for :class:`ArrowDtype` with ``pyarrow.string`` (:issue:`56404`)
 - Bug in :meth:`Series.str.startswith` and :meth:`Series.str.endswith` with arguments of type ``tuple[str, ...]`` for :class:`ArrowDtype` with ``pyarrow.string`` dtype (:issue:`56579`)
diff --git a/pandas/core/arrays/arrow/array.py b/pandas/core/arrays/arrow/array.py
index f7a1ca702891a..860a2cbb44061 100644
--- a/pandas/core/arrays/arrow/array.py
+++ b/pandas/core/arrays/arrow/array.py
@@ -2331,23 +2331,20 @@ def _str_find(self, sub: str, start: int = 0, end: int | None = None) -> Self:
         if (start == 0 or start is None) and end is None:
             result = pc.find_substring(self._pa_array, sub)
         else:
-            result = pc.find_substring(self._pa_array, sub)
-            length = pc.utf8_length(self._pa_array)
             if start is None:
-                start = pa.scalar(0, result.type)
+                start_offset = 0
+                start = 0
             elif start < 0:
-                start = pc.add(start, length)
-            if end is None:
-                end = length
-            elif end < 0:
-                end = pc.add(end, length)
-            found = pc.not_equal(pa.scalar(-1, type=result.type), result)
-            found_in_bounds = pc.and_(
-                pc.greater_equal(result, start), pc.less(result, end)
-            )
-            result = pc.if_else(
-                pc.and_(found, found_in_bounds), result, pa.scalar(-1, type=result.type)
-            )
+                start_offset = pc.add(start, pc.utf8_length(self._pa_array))
+                start_offset = pc.if_else(pc.less(start_offset, 0), 0, start_offset)
+            else:
+                start_offset = start
+            slices = pc.utf8_slice_codeunits(self._pa_array, start, stop=end)
+            result = pc.find_substring(slices, sub)
+            not_found = pc.equal(result, pa.scalar(-1, type=result.type))
+
+            offset_result = pc.add(result, start_offset)
+            result = pc.if_else(not_found, result, offset_result)
         return type(self)(result)
 
     def _str_join(self, sep: str) -> Self:
diff --git a/pandas/tests/extension/test_arrow.py b/pandas/tests/extension/test_arrow.py
index 913a0f1c9a29e..020747be608a9 100644
--- a/pandas/tests/extension/test_arrow.py
+++ b/pandas/tests/extension/test_arrow.py
@@ -1919,13 +1919,18 @@ def test_str_fullmatch(pat, case, na, exp):
 
 
 @pytest.mark.parametrize(
-    "sub, start, end, exp",
-    [["ab", 0, None, [0, None]], ["bc", 1, 3, [1, None]], ["ab", 1, None, [-1, None]]],
+    "sub, start, end, exp, exp_type",
+    [
+        ["ab", 0, None, [0, None], pa.int32()],
+        ["bc", 1, 3, [1, None], pa.int64()],
+        ["ab", 1, None, [-1, None], pa.int64()],
+        ["ab", -3, -3, [-1, None], pa.int64()],
+    ],
 )
-def test_str_find(sub, start, end, exp):
+def test_str_find(sub, start, end, exp, exp_type):
     ser = pd.Series(["abc", None], dtype=ArrowDtype(pa.string()))
     result = ser.str.find(sub, start=start, end=end)
-    expected = pd.Series(exp, dtype=ArrowDtype(pa.int32()))
+    expected = pd.Series(exp, dtype=ArrowDtype(exp_type))
     tm.assert_series_equal(result, expected)
 
 
@@ -1933,15 +1938,15 @@ def test_str_find_negative_start():
     # GH 56411
     ser = pd.Series(["abc", None], dtype=ArrowDtype(pa.string()))
     result = ser.str.find(sub="b", start=-1000, end=3)
-    expected = pd.Series([1, None], dtype=ArrowDtype(pa.int32()))
+    expected = pd.Series([1, None], dtype=ArrowDtype(pa.int64()))
     tm.assert_series_equal(result, expected)
 
 
 def test_str_find_negative_start_negative_end():
-    # GH 56411
+    # GH 56791
     ser = pd.Series(["abcdefg", None], dtype=ArrowDtype(pa.string()))
     result = ser.str.find(sub="d", start=-6, end=-3)
-    expected = pd.Series([3, None], dtype=ArrowDtype(pa.int32()))
+    expected = pd.Series([3, None], dtype=ArrowDtype(pa.int64()))
     tm.assert_series_equal(result, expected)
 
 

From beaf5f02f3c990b61b25cd1542033e014f494315 Mon Sep 17 00:00:00 2001
From: Rohan Jain <rohanjain@microsoft.com>
Date: Mon, 8 Jan 2024 21:34:55 -0500
Subject: [PATCH 03/14] add test for Nones

---
 pandas/tests/extension/test_arrow.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pandas/tests/extension/test_arrow.py b/pandas/tests/extension/test_arrow.py
index 020747be608a9..f769ddbea31b8 100644
--- a/pandas/tests/extension/test_arrow.py
+++ b/pandas/tests/extension/test_arrow.py
@@ -1925,6 +1925,7 @@ def test_str_fullmatch(pat, case, na, exp):
         ["bc", 1, 3, [1, None], pa.int64()],
         ["ab", 1, None, [-1, None], pa.int64()],
         ["ab", -3, -3, [-1, None], pa.int64()],
+        ["ab", None, None, [0, None], pa.int32()],
     ],
 )
 def test_str_find(sub, start, end, exp, exp_type):

From 68763b1176c2ead93d78c7e17dfe8355fc37bd93 Mon Sep 17 00:00:00 2001
From: Rohan Jain <rohanjain@microsoft.com>
Date: Mon, 8 Jan 2024 22:07:14 -0500
Subject: [PATCH 04/14] fix min version compat

---
 pandas/tests/extension/test_arrow.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/pandas/tests/extension/test_arrow.py b/pandas/tests/extension/test_arrow.py
index f769ddbea31b8..d541e1042215c 100644
--- a/pandas/tests/extension/test_arrow.py
+++ b/pandas/tests/extension/test_arrow.py
@@ -1923,9 +1923,8 @@ def test_str_fullmatch(pat, case, na, exp):
     [
         ["ab", 0, None, [0, None], pa.int32()],
         ["bc", 1, 3, [1, None], pa.int64()],
-        ["ab", 1, None, [-1, None], pa.int64()],
+        ["ab", 1, 3, [-1, None], pa.int64()],
         ["ab", -3, -3, [-1, None], pa.int64()],
-        ["ab", None, None, [0, None], pa.int32()],
     ],
 )
 def test_str_find(sub, start, end, exp, exp_type):

From 52a6f528af850c4b76e7fa90d4661d6d246f042e Mon Sep 17 00:00:00 2001
From: Rohan Jain <rohanjain@microsoft.com>
Date: Mon, 8 Jan 2024 22:12:28 -0500
Subject: [PATCH 05/14] restore test

---
 pandas/tests/extension/test_arrow.py | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/pandas/tests/extension/test_arrow.py b/pandas/tests/extension/test_arrow.py
index d541e1042215c..be722863a11a5 100644
--- a/pandas/tests/extension/test_arrow.py
+++ b/pandas/tests/extension/test_arrow.py
@@ -1942,6 +1942,18 @@ def test_str_find_negative_start():
     tm.assert_series_equal(result, expected)
 
 
+def test_str_find_no_end():
+    ser = pd.Series(["abc", None], dtype=ArrowDtype(pa.string()))
+    if pa_version_under13p0:
+        # https://github.com/apache/arrow/issues/36311
+        with pytest.raises(pa.lib.ArrowInvalid, match="Negative buffer resize"):
+            ser.str.find("ab", start=1)
+    else:
+        result = ser.str.find("ab", start=1)
+        expected = pd.Series([-1, None], dtype="int64[pyarrow]")
+        tm.assert_series_equal(result, expected)
+
+
 def test_str_find_negative_start_negative_end():
     # GH 56791
     ser = pd.Series(["abcdefg", None], dtype=ArrowDtype(pa.string()))

From 771e2f64af1fab2545f9b10f9a8a5f4aaab21951 Mon Sep 17 00:00:00 2001
From: Rohan Jain <rohanjain@microsoft.com>
Date: Tue, 9 Jan 2024 11:12:20 -0500
Subject: [PATCH 06/14] improve test cases

---
 pandas/tests/extension/test_arrow.py | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/pandas/tests/extension/test_arrow.py b/pandas/tests/extension/test_arrow.py
index be722863a11a5..7248ef51c0bc5 100644
--- a/pandas/tests/extension/test_arrow.py
+++ b/pandas/tests/extension/test_arrow.py
@@ -1962,6 +1962,27 @@ def test_str_find_negative_start_negative_end():
     tm.assert_series_equal(result, expected)
 
 
+def test_str_find_large_start():
+    # GH 56791
+    ser = pd.Series(["abcdefg", None], dtype=ArrowDtype(pa.string()))
+    if pa_version_under13p0:
+        # https://github.com/apache/arrow/issues/36311
+        with pytest.raises(pa.lib.ArrowInvalid, match="Negative buffer resize"):
+            ser.str.find(sub="d", start=16)
+    else:
+        result = ser.str.find(sub="d", start=16)
+        expected = pd.Series([-1, None], dtype=ArrowDtype(pa.int64()))
+        tm.assert_series_equal(result, expected)
+
+
+def test_str_find_negative_start_negative_end_no_match():
+    # GH 56791
+    ser = pd.Series(["abcdefg", None], dtype=ArrowDtype(pa.string()))
+    result = ser.str.find(sub="d", start=-3, end=-6)
+    expected = pd.Series([-1, None], dtype=ArrowDtype(pa.int64()))
+    tm.assert_series_equal(result, expected)
+
+
 @pytest.mark.parametrize(
     "i, exp",
     [

From 0de96cb3a0a30ebfdce73238e8b9ce235e782cc7 Mon Sep 17 00:00:00 2001
From: Rohan Jain <rohanjain@microsoft.com>
Date: Tue, 9 Jan 2024 15:27:39 -0500
Subject: [PATCH 07/14] fix empty string

---
 pandas/core/arrays/arrow/array.py    | 20 ++++++++++++++++----
 pandas/tests/extension/test_arrow.py | 22 ++++++++++++++++++++++
 2 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/pandas/core/arrays/arrow/array.py b/pandas/core/arrays/arrow/array.py
index 860a2cbb44061..3a29ed3842a35 100644
--- a/pandas/core/arrays/arrow/array.py
+++ b/pandas/core/arrays/arrow/array.py
@@ -2331,20 +2331,32 @@ def _str_find(self, sub: str, start: int = 0, end: int | None = None) -> Self:
         if (start == 0 or start is None) and end is None:
             result = pc.find_substring(self._pa_array, sub)
         else:
+            length = pc.utf8_length(self._pa_array)
             if start is None:
                 start_offset = 0
                 start = 0
             elif start < 0:
-                start_offset = pc.add(start, pc.utf8_length(self._pa_array))
+                start_offset = pc.add(start, length)
                 start_offset = pc.if_else(pc.less(start_offset, 0), 0, start_offset)
             else:
                 start_offset = start
             slices = pc.utf8_slice_codeunits(self._pa_array, start, stop=end)
             result = pc.find_substring(slices, sub)
-            not_found = pc.equal(result, pa.scalar(-1, type=result.type))
-
+            found = pc.not_equal(result, pa.scalar(-1, type=result.type))
+            if end is None:
+                end = length
+            elif end < 0:
+                end = pc.add(end, length)
+                end = pc.if_else(pc.less(end, 0), 0, end)
+            found = pc.and_(
+                found,
+                pc.and_(
+                    pc.less_equal(start_offset, end),
+                    pc.less_equal(start_offset, length),
+                ),
+            )
             offset_result = pc.add(result, start_offset)
-            result = pc.if_else(not_found, result, offset_result)
+            result = pc.if_else(found, offset_result, -1)
         return type(self)(result)
 
     def _str_join(self, sep: str) -> Self:
diff --git a/pandas/tests/extension/test_arrow.py b/pandas/tests/extension/test_arrow.py
index 7248ef51c0bc5..e7aab3497d7d3 100644
--- a/pandas/tests/extension/test_arrow.py
+++ b/pandas/tests/extension/test_arrow.py
@@ -23,6 +23,7 @@
     BytesIO,
     StringIO,
 )
+from itertools import combinations
 import operator
 import pickle
 import re
@@ -1975,6 +1976,27 @@ def test_str_find_large_start():
         tm.assert_series_equal(result, expected)
 
 
+def _get_all_substrings(string):
+    length = len(string) + 1
+    return [string[x:y] for x, y in combinations(range(length), r=2)]
+
+
+@pytest.mark.xfail(
+    pa_version_under13p0, reason="https://github.com/apache/arrow/issues/36311"
+)
+def test_str_find_e2e():
+    string = "abcdefgh"
+    s = pd.Series([string], dtype=ArrowDtype(pa.string()))
+    substrings = _get_all_substrings(string) + ["", "az", "abce"]
+    offsets = list(range(-15, 15)) + [None]
+    for start in offsets:
+        for end in offsets:
+            for sub in substrings:
+                result = s.str.find(sub, start, end)
+                expected = pd.Series([string.find(sub, start, end)], dtype=result.dtype)
+                tm.assert_series_equal(result, expected)
+
+
 def test_str_find_negative_start_negative_end_no_match():
     # GH 56791
     ser = pd.Series(["abcdefg", None], dtype=ArrowDtype(pa.string()))

From f5416e32278d5b416f65a748a45f52346e748231 Mon Sep 17 00:00:00 2001
From: Rohan Jain <rohanjain@microsoft.com>
Date: Tue, 9 Jan 2024 20:54:02 -0500
Subject: [PATCH 08/14] inline

---
 pandas/tests/extension/test_arrow.py | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/pandas/tests/extension/test_arrow.py b/pandas/tests/extension/test_arrow.py
index e7aab3497d7d3..c53503d24bdb7 100644
--- a/pandas/tests/extension/test_arrow.py
+++ b/pandas/tests/extension/test_arrow.py
@@ -1976,19 +1976,18 @@ def test_str_find_large_start():
         tm.assert_series_equal(result, expected)
 
 
-def _get_all_substrings(string):
-    length = len(string) + 1
-    return [string[x:y] for x, y in combinations(range(length), r=2)]
-
-
 @pytest.mark.xfail(
     pa_version_under13p0, reason="https://github.com/apache/arrow/issues/36311"
 )
 def test_str_find_e2e():
-    string = "abcdefgh"
+    string = "abcaadef"
     s = pd.Series([string], dtype=ArrowDtype(pa.string()))
-    substrings = _get_all_substrings(string) + ["", "az", "abce"]
     offsets = list(range(-15, 15)) + [None]
+    substrings = [string[x:y] for x, y in combinations(range(len(string) + 1), r=2)] + [
+        "",
+        "az",
+        "abce",
+    ]
     for start in offsets:
         for end in offsets:
             for sub in substrings:

From 06105ce805ccc57813bd08331fb776f1c6fe84e3 Mon Sep 17 00:00:00 2001
From: Rohan Jain <rohanjain@microsoft.com>
Date: Wed, 10 Jan 2024 18:57:01 -0500
Subject: [PATCH 09/14] improve tests

---
 pandas/tests/extension/test_arrow.py | 29 ++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/pandas/tests/extension/test_arrow.py b/pandas/tests/extension/test_arrow.py
index c53503d24bdb7..2d562753c4789 100644
--- a/pandas/tests/extension/test_arrow.py
+++ b/pandas/tests/extension/test_arrow.py
@@ -1979,21 +1979,26 @@ def test_str_find_large_start():
 @pytest.mark.xfail(
     pa_version_under13p0, reason="https://github.com/apache/arrow/issues/36311"
 )
-def test_str_find_e2e():
-    string = "abcaadef"
-    s = pd.Series([string], dtype=ArrowDtype(pa.string()))
-    offsets = list(range(-15, 15)) + [None]
-    substrings = [string[x:y] for x, y in combinations(range(len(string) + 1), r=2)] + [
+@pytest.mark.parametrize("start", list(range(-15, 15)) + [None])
+@pytest.mark.parametrize("end", list(range(-15, 15)) + [None])
+@pytest.mark.parametrize(
+    "sub",
+    ["abcaadef"[x:y] for x, y in combinations(range(len("abcaadef") + 1), r=2)]
+    + [
         "",
         "az",
         "abce",
-    ]
-    for start in offsets:
-        for end in offsets:
-            for sub in substrings:
-                result = s.str.find(sub, start, end)
-                expected = pd.Series([string.find(sub, start, end)], dtype=result.dtype)
-                tm.assert_series_equal(result, expected)
+    ],
+)
+def test_str_find_e2e(start, end, sub):
+    s = pd.Series(
+        ["abcaadef", "abc", "abcdeddefgj8292", "ab", "a", ""],
+        dtype=ArrowDtype(pa.string()),
+    )
+    object_series = s.astype(pd.StringDtype())
+    result = s.str.find(sub, start, end)
+    expected = object_series.str.find(sub, start, end).astype(result.dtype)
+    tm.assert_series_equal(result, expected)
 
 
 def test_str_find_negative_start_negative_end_no_match():

From 7fa21eb24682ae587a0b3033942fbe1247f98921 Mon Sep 17 00:00:00 2001
From: Rohan Jain <rohanjain@microsoft.com>
Date: Wed, 10 Jan 2024 20:31:04 -0500
Subject: [PATCH 10/14] fix

---
 pandas/tests/extension/test_arrow.py | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/pandas/tests/extension/test_arrow.py b/pandas/tests/extension/test_arrow.py
index 2d562753c4789..a6737d7999a6e 100644
--- a/pandas/tests/extension/test_arrow.py
+++ b/pandas/tests/extension/test_arrow.py
@@ -1979,8 +1979,6 @@ def test_str_find_large_start():
 @pytest.mark.xfail(
     pa_version_under13p0, reason="https://github.com/apache/arrow/issues/36311"
 )
-@pytest.mark.parametrize("start", list(range(-15, 15)) + [None])
-@pytest.mark.parametrize("end", list(range(-15, 15)) + [None])
 @pytest.mark.parametrize(
     "sub",
     ["abcaadef"[x:y] for x, y in combinations(range(len("abcaadef") + 1), r=2)]
@@ -1990,15 +1988,18 @@ def test_str_find_large_start():
         "abce",
     ],
 )
-def test_str_find_e2e(start, end, sub):
+def test_str_find_e2e(sub):
     s = pd.Series(
         ["abcaadef", "abc", "abcdeddefgj8292", "ab", "a", ""],
         dtype=ArrowDtype(pa.string()),
     )
     object_series = s.astype(pd.StringDtype())
-    result = s.str.find(sub, start, end)
-    expected = object_series.str.find(sub, start, end).astype(result.dtype)
-    tm.assert_series_equal(result, expected)
+    offsets = list(range(-15, 15)) + [None]
+    for start in offsets:
+        for end in offsets:
+            result = s.str.find(sub, start, end)
+            expected = object_series.str.find(sub, start, end).astype(result.dtype)
+            tm.assert_series_equal(result, expected)
 
 
 def test_str_find_negative_start_negative_end_no_match():

From 8e27d85647921d2db4b49264cfbf1cec90868713 Mon Sep 17 00:00:00 2001
From: Rohan Jain <rohanjain@microsoft.com>
Date: Wed, 10 Jan 2024 20:35:37 -0500
Subject: [PATCH 11/14] Revert "fix"

This reverts commit 7fa21eb24682ae587a0b3033942fbe1247f98921.
---
 pandas/tests/extension/test_arrow.py | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/pandas/tests/extension/test_arrow.py b/pandas/tests/extension/test_arrow.py
index a6737d7999a6e..2d562753c4789 100644
--- a/pandas/tests/extension/test_arrow.py
+++ b/pandas/tests/extension/test_arrow.py
@@ -1979,6 +1979,8 @@ def test_str_find_large_start():
 @pytest.mark.xfail(
     pa_version_under13p0, reason="https://github.com/apache/arrow/issues/36311"
 )
+@pytest.mark.parametrize("start", list(range(-15, 15)) + [None])
+@pytest.mark.parametrize("end", list(range(-15, 15)) + [None])
 @pytest.mark.parametrize(
     "sub",
     ["abcaadef"[x:y] for x, y in combinations(range(len("abcaadef") + 1), r=2)]
@@ -1988,18 +1990,15 @@ def test_str_find_large_start():
         "abce",
     ],
 )
-def test_str_find_e2e(sub):
+def test_str_find_e2e(start, end, sub):
     s = pd.Series(
         ["abcaadef", "abc", "abcdeddefgj8292", "ab", "a", ""],
         dtype=ArrowDtype(pa.string()),
     )
     object_series = s.astype(pd.StringDtype())
-    offsets = list(range(-15, 15)) + [None]
-    for start in offsets:
-        for end in offsets:
-            result = s.str.find(sub, start, end)
-            expected = object_series.str.find(sub, start, end).astype(result.dtype)
-            tm.assert_series_equal(result, expected)
+    result = s.str.find(sub, start, end)
+    expected = object_series.str.find(sub, start, end).astype(result.dtype)
+    tm.assert_series_equal(result, expected)
 
 
 def test_str_find_negative_start_negative_end_no_match():

From 403bc4f5889ee8376021eacd285b3525fc031249 Mon Sep 17 00:00:00 2001
From: Rohan Jain <rohanjain@microsoft.com>
Date: Wed, 10 Jan 2024 20:36:31 -0500
Subject: [PATCH 12/14] fix

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

diff --git a/pandas/tests/extension/test_arrow.py b/pandas/tests/extension/test_arrow.py
index 2d562753c4789..3b5ea67b2f2ca 100644
--- a/pandas/tests/extension/test_arrow.py
+++ b/pandas/tests/extension/test_arrow.py
@@ -1976,7 +1976,7 @@ def test_str_find_large_start():
         tm.assert_series_equal(result, expected)
 
 
-@pytest.mark.xfail(
+@pytest.mark.skipif(
     pa_version_under13p0, reason="https://github.com/apache/arrow/issues/36311"
 )
 @pytest.mark.parametrize("start", list(range(-15, 15)) + [None])

From ef9a79161c78a224a3f1f1bb3ac03d9cdfc32cca Mon Sep 17 00:00:00 2001
From: Rohan Jain <rohanjain@microsoft.com>
Date: Sat, 20 Jan 2024 13:37:33 -0500
Subject: [PATCH 13/14] merge

---
 doc/source/whatsnew/v2.2.0.rst    |  1 -
 pandas/core/arrays/arrow/array.py | 16 ++++------------
 2 files changed, 4 insertions(+), 13 deletions(-)

diff --git a/doc/source/whatsnew/v2.2.0.rst b/doc/source/whatsnew/v2.2.0.rst
index 7f1624001c8d3..d9ab0452c8334 100644
--- a/doc/source/whatsnew/v2.2.0.rst
+++ b/doc/source/whatsnew/v2.2.0.rst
@@ -823,7 +823,6 @@ Strings
 - Bug in :meth:`DataFrame.reindex` not matching :class:`Index` with ``string[pyarrow_numpy]`` dtype (:issue:`56106`)
 - Bug in :meth:`Index.str.cat` always casting result to object dtype (:issue:`56157`)
 - Bug in :meth:`Series.__mul__` for :class:`ArrowDtype` with ``pyarrow.string`` dtype and ``string[pyarrow]`` for the pyarrow backend (:issue:`51970`)
-- Bug in :meth:`Series.str.find` when ``start < 0`` and ``end < 0`` for :class:`ArrowDtype` with ``pyarrow.string`` (:issue:`56791`)
 - Bug in :meth:`Series.str.find` when ``start < 0`` for :class:`ArrowDtype` with ``pyarrow.string`` (:issue:`56411`)
 - Bug in :meth:`Series.str.fullmatch` when ``dtype=pandas.ArrowDtype(pyarrow.string()))`` allows partial matches when regex ends in literal //$ (:issue:`56652`)
 - Bug in :meth:`Series.str.replace` when ``n < 0`` for :class:`ArrowDtype` with ``pyarrow.string`` (:issue:`56404`)
diff --git a/pandas/core/arrays/arrow/array.py b/pandas/core/arrays/arrow/array.py
index 8478e82b69db9..8f8881ffdc40d 100644
--- a/pandas/core/arrays/arrow/array.py
+++ b/pandas/core/arrays/arrow/array.py
@@ -2371,6 +2371,10 @@ def _str_find(self, sub: str, start: int = 0, end: int | None = None) -> Self:
         if (start == 0 or start is None) and end is None:
             result = pc.find_substring(self._pa_array, sub)
         else:
+            if sub == "":
+                # GH 56792
+                result = self._apply_elementwise(lambda val: val.find(sub, start, end))
+                return type(self)(pa.chunked_array(result))
             length = pc.utf8_length(self._pa_array)
             if start is None:
                 start_offset = 0
@@ -2383,18 +2387,6 @@ def _str_find(self, sub: str, start: int = 0, end: int | None = None) -> Self:
             slices = pc.utf8_slice_codeunits(self._pa_array, start, stop=end)
             result = pc.find_substring(slices, sub)
             found = pc.not_equal(result, pa.scalar(-1, type=result.type))
-            if end is None:
-                end = length
-            elif end < 0:
-                end = pc.add(end, length)
-                end = pc.if_else(pc.less(end, 0), 0, end)
-            found = pc.and_(
-                found,
-                pc.and_(
-                    pc.less_equal(start_offset, end),
-                    pc.less_equal(start_offset, length),
-                ),
-            )
             offset_result = pc.add(result, start_offset)
             result = pc.if_else(found, offset_result, -1)
         return type(self)(result)

From 2cf0fbfa857865858403d34ee936091caa22cf7f Mon Sep 17 00:00:00 2001
From: Rohan Jain <rohanjain@microsoft.com>
Date: Mon, 22 Jan 2024 09:09:25 -0500
Subject: [PATCH 14/14] inline

---
 pandas/core/arrays/arrow/array.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/pandas/core/arrays/arrow/array.py b/pandas/core/arrays/arrow/array.py
index 8f8881ffdc40d..31932579d207b 100644
--- a/pandas/core/arrays/arrow/array.py
+++ b/pandas/core/arrays/arrow/array.py
@@ -2375,12 +2375,11 @@ def _str_find(self, sub: str, start: int = 0, end: int | None = None) -> Self:
                 # GH 56792
                 result = self._apply_elementwise(lambda val: val.find(sub, start, end))
                 return type(self)(pa.chunked_array(result))
-            length = pc.utf8_length(self._pa_array)
             if start is None:
                 start_offset = 0
                 start = 0
             elif start < 0:
-                start_offset = pc.add(start, length)
+                start_offset = pc.add(start, pc.utf8_length(self._pa_array))
                 start_offset = pc.if_else(pc.less(start_offset, 0), 0, start_offset)
             else:
                 start_offset = start