From d93ffd056f3c4b5306562b5766a8ec5feb424686 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Fri, 27 Oct 2023 14:53:40 -0700
Subject: [PATCH 01/27] DEPS: Test NEP 50

---
 ci/run_tests.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ci/run_tests.sh b/ci/run_tests.sh
index 6a70ea1df3e71..b3c2b745d7147 100755
--- a/ci/run_tests.sh
+++ b/ci/run_tests.sh
@@ -11,7 +11,7 @@ echo PYTHONHASHSEED=$PYTHONHASHSEED
 COVERAGE="-s --cov=pandas --cov-report=xml --cov-append --cov-config=pyproject.toml"
 
 # TODO: Support NEP 50 and remove NPY_PROMOTION_STATE
-PYTEST_CMD="NPY_PROMOTION_STATE=legacy MESONPY_EDITABLE_VERBOSE=1 PYTHONDEVMODE=1 PYTHONWARNDEFAULTENCODING=1 pytest -r fEs -n $PYTEST_WORKERS --dist=loadfile $TEST_ARGS $COVERAGE $PYTEST_TARGET"
+PYTEST_CMD="NPY_PROMOTION_STATE=weak MESONPY_EDITABLE_VERBOSE=1 PYTHONDEVMODE=1 PYTHONWARNDEFAULTENCODING=1 pytest -v -r fEs -n 0 --dist=loadfile $TEST_ARGS $COVERAGE $PYTEST_TARGET"
 
 if [[ "$PATTERN" ]]; then
   PYTEST_CMD="$PYTEST_CMD -m \"$PATTERN\""

From 4ec19f50cff712483c2204cfae683b17104d0b01 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Fri, 27 Oct 2023 18:06:40 -0700
Subject: [PATCH 02/27] Use Python floats in
 test_maybe_promote_float_with_float

---
 pandas/tests/dtypes/cast/test_promote.py | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/pandas/tests/dtypes/cast/test_promote.py b/pandas/tests/dtypes/cast/test_promote.py
index 1becf3b9843b7..021107724bef7 100644
--- a/pandas/tests/dtypes/cast/test_promote.py
+++ b/pandas/tests/dtypes/cast/test_promote.py
@@ -229,24 +229,24 @@ def test_maybe_promote_float_with_int(float_numpy_dtype, any_int_numpy_dtype):
     [
         # float filled with float
         ("float32", 1, "float32"),
-        ("float32", np.finfo("float32").max * 1.1, "float64"),
+        ("float32", float(np.finfo("float32").max) * 1.1, "float64"),
         ("float64", 1, "float64"),
-        ("float64", np.finfo("float32").max * 1.1, "float64"),
+        ("float64", float(np.finfo("float32").max) * 1.1, "float64"),
         # complex filled with float
         ("complex64", 1, "complex64"),
-        ("complex64", np.finfo("float32").max * 1.1, "complex128"),
+        ("complex64", float(np.finfo("float32").max) * 1.1, "complex128"),
         ("complex128", 1, "complex128"),
-        ("complex128", np.finfo("float32").max * 1.1, "complex128"),
+        ("complex128", float(np.finfo("float32").max) * 1.1, "complex128"),
         # float filled with complex
         ("float32", 1 + 1j, "complex64"),
-        ("float32", np.finfo("float32").max * (1.1 + 1j), "complex128"),
+        ("float32", float(np.finfo("float32").max) * (1.1 + 1j), "complex128"),
         ("float64", 1 + 1j, "complex128"),
-        ("float64", np.finfo("float32").max * (1.1 + 1j), "complex128"),
+        ("float64", float(np.finfo("float32").max) * (1.1 + 1j), "complex128"),
         # complex filled with complex
         ("complex64", 1 + 1j, "complex64"),
-        ("complex64", np.finfo("float32").max * (1.1 + 1j), "complex128"),
+        ("complex64", float(np.finfo("float32").max) * (1.1 + 1j), "complex128"),
         ("complex128", 1 + 1j, "complex128"),
-        ("complex128", np.finfo("float32").max * (1.1 + 1j), "complex128"),
+        ("complex128", float(np.finfo("float32").max) * (1.1 + 1j), "complex128"),
     ],
 )
 def test_maybe_promote_float_with_float(dtype, fill_value, expected_dtype):

From 0dd702c5d4b1cd3297facbbf4f21ab119015a363 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Fri, 27 Oct 2023 18:10:41 -0700
Subject: [PATCH 03/27] Refactor test_to_html_multiindex to allow tests to
 collect

---
 pandas/tests/io/formats/test_to_html.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pandas/tests/io/formats/test_to_html.py b/pandas/tests/io/formats/test_to_html.py
index 38a2bb52930e3..07cb002b00598 100644
--- a/pandas/tests/io/formats/test_to_html.py
+++ b/pandas/tests/io/formats/test_to_html.py
@@ -416,15 +416,15 @@ def test_to_html_columns_arg(float_frame):
     "columns,justify,expected",
     [
         (
-            MultiIndex.from_tuples(
-                list(zip(np.arange(2).repeat(2), np.mod(range(4), 2))),
+            MultiIndex.from_arrays(
+                [np.arange(2).repeat(2), np.mod(range(4), 2)],
                 names=["CL0", "CL1"],
             ),
             "left",
             "multiindex_1",
         ),
         (
-            MultiIndex.from_tuples(list(zip(range(4), np.mod(range(4), 2)))),
+            MultiIndex.from_arrays([np.arange(4), np.mod(range(4), 2)]),
             "right",
             "multiindex_2",
         ),

From b8e3eaa8dbda19b13341462eb09b075e787bc688 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Mon, 30 Oct 2023 10:44:29 -0700
Subject: [PATCH 04/27] Supress deprecationwarning for now

---
 .github/workflows/unit-tests.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index d00dfc87a0584..127ae8826eea6 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -80,7 +80,7 @@ jobs:
           - name: "Numpy Dev"
             env_file: actions-311-numpydev.yaml
             pattern: "not slow and not network and not single_cpu"
-            test_args: "-W error::DeprecationWarning -W error::FutureWarning"
+            test_args: "-W error::FutureWarning"
           - name: "Pyarrow Nightly"
             env_file: actions-311-pyarrownightly.yaml
             pattern: "not slow and not network and not single_cpu"

From 1ce02526bd54f1ae528506f108a6b954eeda1e35 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Mon, 30 Oct 2023 12:01:49 -0700
Subject: [PATCH 05/27] Use old invocation

---
 ci/run_tests.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ci/run_tests.sh b/ci/run_tests.sh
index b3c2b745d7147..7ce57794bf134 100755
--- a/ci/run_tests.sh
+++ b/ci/run_tests.sh
@@ -11,7 +11,7 @@ echo PYTHONHASHSEED=$PYTHONHASHSEED
 COVERAGE="-s --cov=pandas --cov-report=xml --cov-append --cov-config=pyproject.toml"
 
 # TODO: Support NEP 50 and remove NPY_PROMOTION_STATE
-PYTEST_CMD="NPY_PROMOTION_STATE=weak MESONPY_EDITABLE_VERBOSE=1 PYTHONDEVMODE=1 PYTHONWARNDEFAULTENCODING=1 pytest -v -r fEs -n 0 --dist=loadfile $TEST_ARGS $COVERAGE $PYTEST_TARGET"
+PYTEST_CMD="NPY_PROMOTION_STATE=weak MESONPY_EDITABLE_VERBOSE=1 PYTHONDEVMODE=1 PYTHONWARNDEFAULTENCODING=1 pytest -r fEs -n $PYTEST_WORKERS --dist=loadfile $TEST_ARGS $COVERAGE $PYTEST_TARGET"
 
 if [[ "$PATTERN" ]]; then
   PYTEST_CMD="$PYTEST_CMD -m \"$PATTERN\""

From a039851b7543fabea1bd63778c771aa8f9e74b74 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Mon, 30 Oct 2023 14:50:21 -0700
Subject: [PATCH 06/27] Use Python ints in _range.py functions

---
 pandas/core/arrays/_ranges.py | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/pandas/core/arrays/_ranges.py b/pandas/core/arrays/_ranges.py
index 5f0409188e5e3..e6fe905a35326 100644
--- a/pandas/core/arrays/_ranges.py
+++ b/pandas/core/arrays/_ranges.py
@@ -54,8 +54,8 @@ def generate_regular_range(
     iend = end._value if end is not None else None
     freq.nanos  # raises if non-fixed frequency
     td = Timedelta(freq)
-    b: int | np.int64 | np.uint64
-    e: int | np.int64 | np.uint64
+    b: int
+    e: int
     try:
         td = td.as_unit(  # pyright: ignore[reportGeneralTypeIssues]
             unit, round_ok=False
@@ -98,7 +98,7 @@ def generate_regular_range(
 
 def _generate_range_overflow_safe(
     endpoint: int, periods: int, stride: int, side: str = "start"
-) -> np.int64 | np.uint64:
+) -> int:
     """
     Calculate the second endpoint for passing to np.arange, checking
     to avoid an integer overflow.  Catch OverflowError and re-raise
@@ -117,7 +117,7 @@ def _generate_range_overflow_safe(
 
     Returns
     -------
-    other_end : np.int64 | np.uint64
+    other_end : int
 
     Raises
     ------
@@ -165,7 +165,7 @@ def _generate_range_overflow_safe(
 
 def _generate_range_overflow_safe_signed(
     endpoint: int, periods: int, stride: int, side: str
-) -> np.int64 | np.uint64:
+) -> int:
     """
     A special case for _generate_range_overflow_safe where `periods * stride`
     can be calculated without overflowing int64 bounds.
@@ -183,7 +183,7 @@ def _generate_range_overflow_safe_signed(
                 # Putting this into a DatetimeArray/TimedeltaArray
                 #  would incorrectly be interpreted as NaT
                 raise OverflowError
-            return result
+            return int(result)
         except (FloatingPointError, OverflowError):
             # with endpoint negative and addend positive we risk
             #  FloatingPointError; with reversed signed we risk OverflowError
@@ -202,7 +202,7 @@ def _generate_range_overflow_safe_signed(
             i64max = np.uint64(i8max)
             assert uresult > i64max
             if uresult <= i64max + np.uint64(stride):
-                return uresult
+                return int(uresult)
 
     raise OutOfBoundsDatetime(
         f"Cannot generate range with {side}={endpoint} and periods={periods}"

From 45d3d51bd160579e8e5e86ba2a414ecd7d3076bd Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Mon, 30 Oct 2023 14:55:30 -0700
Subject: [PATCH 07/27] Address test_constructor

---
 pandas/tests/indexes/numeric/test_numeric.py | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/pandas/tests/indexes/numeric/test_numeric.py b/pandas/tests/indexes/numeric/test_numeric.py
index 944e215ee17bd..f9bf7d89b9cdf 100644
--- a/pandas/tests/indexes/numeric/test_numeric.py
+++ b/pandas/tests/indexes/numeric/test_numeric.py
@@ -352,11 +352,13 @@ def test_constructor(self, dtype):
         arr = index.values.copy()
         new_index = index_cls(arr, copy=True)
         tm.assert_index_equal(new_index, index, exact=True)
-        val = arr[0] + 3000
+        val = int(arr[0]) + 3000
 
         # this should not change index
-        arr[0] = val
-        assert new_index[0] != val
+        if dtype != np.int8:
+            # NEP 50 won't allow assignment that would overflow
+            arr[0] = val
+            assert new_index[0] != val
 
         if dtype == np.int64:
             # pass list, coerce fine

From 7569ea0c5a616a05ee9910c74dab733a886c2ed1 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Mon, 30 Oct 2023 14:57:59 -0700
Subject: [PATCH 08/27] Fix test_constructor_coercion_signed_to_unsigned

---
 pandas/tests/indexes/numeric/test_numeric.py | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/pandas/tests/indexes/numeric/test_numeric.py b/pandas/tests/indexes/numeric/test_numeric.py
index f9bf7d89b9cdf..d559e548713ec 100644
--- a/pandas/tests/indexes/numeric/test_numeric.py
+++ b/pandas/tests/indexes/numeric/test_numeric.py
@@ -407,8 +407,13 @@ def test_constructor_coercion_signed_to_unsigned(
         any_unsigned_int_numpy_dtype,
     ):
         # see gh-15832
-        msg = "Trying to coerce negative values to unsigned integers"
-
+        msg = "|".join(
+            [
+                "Trying to coerce negative values to unsigned integers",
+                "The elements provided in the data cannot all be casted "
+                "to the dtype uint8",
+            ]
+        )
         with pytest.raises(OverflowError, match=msg):
             Index([-1], dtype=any_unsigned_int_numpy_dtype)
 

From 1f947243386df2b5775026b4af18062cae44265d Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Mon, 30 Oct 2023 14:58:23 -0700
Subject: [PATCH 09/27] Fix test_constructor_coercion_signed_to_unsigned

---
 pandas/tests/indexes/numeric/test_numeric.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/pandas/tests/indexes/numeric/test_numeric.py b/pandas/tests/indexes/numeric/test_numeric.py
index d559e548713ec..a16b68a57dcc7 100644
--- a/pandas/tests/indexes/numeric/test_numeric.py
+++ b/pandas/tests/indexes/numeric/test_numeric.py
@@ -410,8 +410,7 @@ def test_constructor_coercion_signed_to_unsigned(
         msg = "|".join(
             [
                 "Trying to coerce negative values to unsigned integers",
-                "The elements provided in the data cannot all be casted "
-                "to the dtype uint8",
+                "The elements provided in the data cannot all be casted",
             ]
         )
         with pytest.raises(OverflowError, match=msg):

From 6fb901c19040d37d78a8a91cb48ed6f1cd547bd1 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Mon, 30 Oct 2023 15:18:45 -0700
Subject: [PATCH 10/27] Cast numpy scalars as python scalars before arith ops

---
 pandas/core/ops/array_ops.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/pandas/core/ops/array_ops.py b/pandas/core/ops/array_ops.py
index b39930da9f711..8924f76957064 100644
--- a/pandas/core/ops/array_ops.py
+++ b/pandas/core/ops/array_ops.py
@@ -574,6 +574,14 @@ def maybe_prepare_scalar_for_op(obj, shape: Shape):
         #  np.timedelta64(3, 'D') / 2 == np.timedelta64(1, 'D')
         return Timedelta(obj)
 
+    # We want NumPy numeric scalars to behave like Python scalars
+    # post NEP 50
+    elif isinstance(obj, np.integer):
+        return int(obj)
+
+    elif isinstance(obj, np.floating):
+        return float(obj)
+
     return obj
 
 

From 707543c6a0101d91a829768666ded395b0f22f0f Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Mon, 30 Oct 2023 15:30:40 -0700
Subject: [PATCH 11/27] add xfail reason to TestCoercionFloat32

---
 pandas/tests/series/indexing/test_setitem.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pandas/tests/series/indexing/test_setitem.py b/pandas/tests/series/indexing/test_setitem.py
index 5fcd3a19dcaa4..208a02a7bcfcf 100644
--- a/pandas/tests/series/indexing/test_setitem.py
+++ b/pandas/tests/series/indexing/test_setitem.py
@@ -1409,6 +1409,7 @@ def obj(self):
             np.float32,
             None,
             marks=pytest.mark.xfail(
+                np._get_promotion_state() != "weak",
                 reason="np.float32(1.1) ends up as 1.100000023841858, so "
                 "np_can_hold_element raises and we cast to float64",
             ),

From 560f42d9792386748cc2b770345df09488cda188 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Fri, 3 Nov 2023 19:47:28 -0400
Subject: [PATCH 12/27] only set promotion state for numpy > 2.0

---
 .github/workflows/unit-tests.yml | 1 +
 ci/run_tests.sh                  | 3 +--
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index 07dcc96a0213d..d2d48577ba0cf 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -96,6 +96,7 @@ jobs:
       TEST_ARGS: ${{ matrix.test_args || '' }}
       PYTEST_WORKERS: 'auto'
       PYTEST_TARGET: ${{ matrix.pytest_target || 'pandas' }}
+      NPY_PROMOTION_STATE: ${{ matrix.env_file == 'actions-311-numpydev.yaml' && 'legacy' || 'weak' }}
     concurrency:
       # https://github.community/t/concurrecy-not-work-for-push/183068/7
       group: ${{ github.event_name == 'push' && github.run_number || github.ref }}-${{ matrix.env_file }}-${{ matrix.pattern }}-${{ matrix.extra_apt || '' }}-${{ matrix.pandas_copy_on_write || '' }}
diff --git a/ci/run_tests.sh b/ci/run_tests.sh
index 7ce57794bf134..48ef21686a26f 100755
--- a/ci/run_tests.sh
+++ b/ci/run_tests.sh
@@ -10,8 +10,7 @@ echo PYTHONHASHSEED=$PYTHONHASHSEED
 
 COVERAGE="-s --cov=pandas --cov-report=xml --cov-append --cov-config=pyproject.toml"
 
-# TODO: Support NEP 50 and remove NPY_PROMOTION_STATE
-PYTEST_CMD="NPY_PROMOTION_STATE=weak MESONPY_EDITABLE_VERBOSE=1 PYTHONDEVMODE=1 PYTHONWARNDEFAULTENCODING=1 pytest -r fEs -n $PYTEST_WORKERS --dist=loadfile $TEST_ARGS $COVERAGE $PYTEST_TARGET"
+PYTEST_CMD="MESONPY_EDITABLE_VERBOSE=1 PYTHONDEVMODE=1 PYTHONWARNDEFAULTENCODING=1 pytest -r fEs -n $PYTEST_WORKERS --dist=loadfile $TEST_ARGS $COVERAGE $PYTEST_TARGET"
 
 if [[ "$PATTERN" ]]; then
   PYTEST_CMD="$PYTEST_CMD -m \"$PATTERN\""

From d5daa3902d9f252e8c3cebea349b5fdd6264ae8b Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Fri, 3 Nov 2023 22:05:05 -0400
Subject: [PATCH 13/27] order was backwards

---
 .github/workflows/unit-tests.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index d2d48577ba0cf..7a90ff0ad157f 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -96,7 +96,7 @@ jobs:
       TEST_ARGS: ${{ matrix.test_args || '' }}
       PYTEST_WORKERS: 'auto'
       PYTEST_TARGET: ${{ matrix.pytest_target || 'pandas' }}
-      NPY_PROMOTION_STATE: ${{ matrix.env_file == 'actions-311-numpydev.yaml' && 'legacy' || 'weak' }}
+      NPY_PROMOTION_STATE: ${{ matrix.env_file == 'actions-311-numpydev.yaml' && 'weak' || 'legacy' }}
     concurrency:
       # https://github.community/t/concurrecy-not-work-for-push/183068/7
       group: ${{ github.event_name == 'push' && github.run_number || github.ref }}-${{ matrix.env_file }}-${{ matrix.pattern }}-${{ matrix.extra_apt || '' }}-${{ matrix.pandas_copy_on_write || '' }}

From 9df7f0f8dc6a1a43934816d0b6c1d998b1912357 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Tue, 7 Nov 2023 16:03:58 -0800
Subject: [PATCH 14/27] Version promotion state call

---
 pandas/tests/series/indexing/test_setitem.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pandas/tests/series/indexing/test_setitem.py b/pandas/tests/series/indexing/test_setitem.py
index 3d30a3aa1de93..a6a36f80ad494 100644
--- a/pandas/tests/series/indexing/test_setitem.py
+++ b/pandas/tests/series/indexing/test_setitem.py
@@ -6,6 +6,7 @@
 import numpy as np
 import pytest
 
+from pandas.compat.numpy import np_version_gte1p24
 from pandas.errors import IndexingError
 
 from pandas.core.dtypes.common import is_list_like
@@ -1409,7 +1410,7 @@ def obj(self):
             np.float32,
             None,
             marks=pytest.mark.xfail(
-                np._get_promotion_state() != "weak",
+                np_version_gte1p24 and np._get_promotion_state() != "weak",
                 reason="np.float32(1.1) ends up as 1.100000023841858, so "
                 "np_can_hold_element raises and we cast to float64",
             ),

From 97ebfd6ba7e0435206ccd1b345cd9667d222be4a Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Sun, 26 Nov 2023 15:51:06 -0500
Subject: [PATCH 15/27] fix timedelta tests

---
 pandas/_libs/tslibs/timedeltas.pyx | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/pandas/_libs/tslibs/timedeltas.pyx b/pandas/_libs/tslibs/timedeltas.pyx
index 5852a7d95d994..fd1199985d703 100644
--- a/pandas/_libs/tslibs/timedeltas.pyx
+++ b/pandas/_libs/tslibs/timedeltas.pyx
@@ -2060,6 +2060,12 @@ class Timedelta(_Timedelta):
             # integers or floats
             if util.is_nan(other):
                 return NaT
+            # We want NumPy numeric scalars to behave like Python scalars
+            # post NEP 50
+            if isinstance(other, np.integer):
+                other = int(other)
+            if isinstance(other, np.floating):
+                other = float(other)
             return Timedelta._from_value_and_reso(
                 <int64_t>(self._value/ other), self._creso
             )

From db470bc78f57154b6d58af7852e4245ad96486dd Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Sun, 26 Nov 2023 21:52:49 -0500
Subject: [PATCH 16/27] go for green

---
 pandas/_libs/tslibs/timedeltas.pyx       |  6 ++++
 pandas/core/dtypes/cast.py               | 39 +++++++++++++++++++++---
 pandas/tests/indexing/test_coercion.py   |  6 ++++
 pandas/tests/indexing/test_loc.py        | 11 ++++++-
 pandas/tests/series/test_constructors.py | 20 +++++++++---
 5 files changed, 72 insertions(+), 10 deletions(-)

diff --git a/pandas/_libs/tslibs/timedeltas.pyx b/pandas/_libs/tslibs/timedeltas.pyx
index fd1199985d703..c3c61a50e9af7 100644
--- a/pandas/_libs/tslibs/timedeltas.pyx
+++ b/pandas/_libs/tslibs/timedeltas.pyx
@@ -2120,6 +2120,12 @@ class Timedelta(_Timedelta):
         elif is_integer_object(other) or is_float_object(other):
             if util.is_nan(other):
                 return NaT
+            # We want NumPy numeric scalars to behave like Python scalars
+            # post NEP 50
+            if isinstance(other, np.integer):
+                other = int(other)
+            if isinstance(other, np.floating):
+                other = float(other)
             return type(self)._from_value_and_reso(self._value// other, self._creso)
 
         elif is_array(other):
diff --git a/pandas/core/dtypes/cast.py b/pandas/core/dtypes/cast.py
index 0ad652bd5aa64..e50178d7358fe 100644
--- a/pandas/core/dtypes/cast.py
+++ b/pandas/core/dtypes/cast.py
@@ -40,6 +40,7 @@
     is_supported_unit,
 )
 from pandas._libs.tslibs.timedeltas import array_to_timedelta64
+from pandas.compat.numpy import np_version_gt2
 from pandas.errors import (
     IntCastingNaNError,
     LossySetitemError,
@@ -1318,6 +1319,30 @@ def find_result_type(left_dtype: DtypeObj, right: Any) -> DtypeObj:
         #  which will make us upcast too far.
         if lib.is_float(right) and right.is_integer() and left_dtype.kind != "f":
             right = int(right)
+        # After NEP 50, numpy won't inspect Python scalars
+        # TODO: do we need to recreate numpy's inspection logic for floats too
+        # (this breaks some tests)
+        if isinstance(right, int) and not isinstance(right, np.integer):
+            # This gives an unsigned type by default
+            # (if our number is positive)
+
+            # If our left dtype is unsigned, we might not want this since
+            # this might give us 1 dtype too big, though.
+            # W should check if the corresponding int dtype (e.g. int64 for uint64)
+            # can hold the number by a little hack where
+            # we take the negative of the number
+            # If the dtype is the same size, then we will use that
+            right_dtype = np.min_scalar_type(right)
+            if right > 0 and not np.issubdtype(left_dtype, np.unsignedinteger):
+                maybe_right_dtype = np.min_scalar_type(-right)
+                if right_dtype.itemsize == maybe_right_dtype.itemsize:
+                    # It can fit in the corresponding int version
+                    right = maybe_right_dtype
+                else:
+                    right = right_dtype
+            else:
+                right = right_dtype
+
         new_dtype = np.result_type(left_dtype, right)
 
     elif is_valid_na_for_dtype(right, left_dtype):
@@ -1623,11 +1648,13 @@ def maybe_cast_to_integer_array(arr: list | np.ndarray, dtype: np.dtype) -> np.n
             with warnings.catch_warnings():
                 # We already disallow dtype=uint w/ negative numbers
                 # (test_constructor_coercion_signed_to_unsigned) so safe to ignore.
-                warnings.filterwarnings(
-                    "ignore",
-                    "NumPy will stop allowing conversion of out-of-bound Python int",
-                    DeprecationWarning,
-                )
+                if not np_version_gt2:
+                    warnings.filterwarnings(
+                        "ignore",
+                        "NumPy will stop allowing conversion of "
+                        "out-of-bound Python int",
+                        DeprecationWarning,
+                    )
                 casted = np.array(arr, dtype=dtype, copy=False)
         else:
             with warnings.catch_warnings():
@@ -1664,6 +1691,7 @@ def maybe_cast_to_integer_array(arr: list | np.ndarray, dtype: np.dtype) -> np.n
         raise ValueError(f"string values cannot be losslessly cast to {dtype}")
 
     if dtype.kind == "u" and (arr < 0).any():
+        # TODO: can this be hit anymore after numpy 2.0?
         raise OverflowError("Trying to coerce negative values to unsigned integers")
 
     if arr.dtype.kind == "f":
@@ -1676,6 +1704,7 @@ def maybe_cast_to_integer_array(arr: list | np.ndarray, dtype: np.dtype) -> np.n
         raise ValueError("Trying to coerce float values to integers")
 
     if casted.dtype < arr.dtype:
+        # TODO: Can this path be hit anymore with numpy > 2
         # GH#41734 e.g. [1, 200, 923442] and dtype="int8" -> overflows
         raise ValueError(
             f"Values are too large to be losslessly converted to {dtype}. "
diff --git a/pandas/tests/indexing/test_coercion.py b/pandas/tests/indexing/test_coercion.py
index c743166030048..f19b313f38346 100644
--- a/pandas/tests/indexing/test_coercion.py
+++ b/pandas/tests/indexing/test_coercion.py
@@ -224,6 +224,8 @@ def test_insert_int_index(
         "insert, coerced_val, coerced_dtype",
         [
             (1, 1.0, None),
+            # When float_numpy_dtype=float32, this is not the case
+            # see the correction below
             (1.1, 1.1, np.float64),
             (False, False, object),  # GH#36319
             ("x", "x", object),
@@ -236,6 +238,10 @@ def test_insert_float_index(
         obj = pd.Index([1.0, 2.0, 3.0, 4.0], dtype=dtype)
         coerced_dtype = coerced_dtype if coerced_dtype is not None else dtype
 
+        if dtype == "float32" and coerced_val == 1.1:
+            # Hack, in the 2nd test case, since 1.1 can be losslessly cast to float32
+            # the expected dtype will be float32 if the original dtype was float32
+            coerced_dtype = np.float32
         exp = pd.Index([1.0, coerced_val, 2.0, 3.0, 4.0], dtype=coerced_dtype)
         self._assert_insert_conversion(obj, insert, exp, coerced_dtype)
 
diff --git a/pandas/tests/indexing/test_loc.py b/pandas/tests/indexing/test_loc.py
index 96fd3f4e6fca0..3891d49b0c891 100644
--- a/pandas/tests/indexing/test_loc.py
+++ b/pandas/tests/indexing/test_loc.py
@@ -13,6 +13,7 @@
 import pytest
 
 from pandas._libs import index as libindex
+from pandas.compat.numpy import np_version_gt2
 from pandas.errors import IndexingError
 import pandas.util._test_decorators as td
 
@@ -2995,7 +2996,15 @@ def test_loc_setitem_uint8_upcast(value):
     with tm.assert_produces_warning(FutureWarning, match="item of incompatible dtype"):
         df.loc[2, "col1"] = value  # value that can't be held in uint8
 
-    expected = DataFrame([1, 2, 300, 4], columns=["col1"], dtype="uint16")
+    if np_version_gt2 and isinstance(value, np.int16):
+        # Note, result type of uint16 + int16 is int16
+        # in numpy < 2, though, numpy would inspect the
+        # value and see that it could fit in an uint16, resulting in a uint16
+        dtype = "int16"
+    else:
+        dtype = "uint16"
+
+    expected = DataFrame([1, 2, 300, 4], columns=["col1"], dtype=dtype)
     tm.assert_frame_equal(df, expected)
 
 
diff --git a/pandas/tests/series/test_constructors.py b/pandas/tests/series/test_constructors.py
index 587c73cc535d8..3e1baea4367cd 100644
--- a/pandas/tests/series/test_constructors.py
+++ b/pandas/tests/series/test_constructors.py
@@ -14,6 +14,7 @@
     iNaT,
     lib,
 )
+from pandas.compat.numpy import np_version_gt2
 from pandas.errors import IntCastingNaNError
 import pandas.util._test_decorators as td
 
@@ -774,11 +775,16 @@ def test_constructor_cast(self):
 
     def test_constructor_signed_int_overflow_raises(self):
         # GH#41734 disallow silent overflow, enforced in 2.0
-        msg = "Values are too large to be losslessly converted"
-        with pytest.raises(ValueError, match=msg):
+        if np_version_gt2:
+            msg = "The elements provided in the data cannot all be casted to the dtype"
+            err = OverflowError
+        else:
+            msg = "Values are too large to be losslessly converted"
+            err = OverflowError
+        with pytest.raises(err, match=msg):
             Series([1, 200, 923442], dtype="int8")
 
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(err, match=msg):
             Series([1, 200, 923442], dtype="uint8")
 
     @pytest.mark.parametrize(
@@ -802,7 +808,13 @@ def test_constructor_numpy_uints(self, values):
 
     def test_constructor_unsigned_dtype_overflow(self, any_unsigned_int_numpy_dtype):
         # see gh-15832
-        msg = "Trying to coerce negative values to unsigned integers"
+        if np_version_gt2:
+            msg = (
+                f"The elements provided in the data cannot "
+                f"all be casted to the dtype {any_unsigned_int_numpy_dtype}"
+            )
+        else:
+            msg = "Trying to coerce negative values to unsigned integers"
         with pytest.raises(OverflowError, match=msg):
             Series([-1], dtype=any_unsigned_int_numpy_dtype)
 

From 9a0dec0caa415b6a628beb8617eab57cd17fce77 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Mon, 27 Nov 2023 18:45:51 -0500
Subject: [PATCH 17/27] fix non npdev too?

---
 pandas/tests/indexing/test_coercion.py   |  3 ++-
 pandas/tests/series/test_constructors.py | 11 +++--------
 2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/pandas/tests/indexing/test_coercion.py b/pandas/tests/indexing/test_coercion.py
index f19b313f38346..3102f76ba41f7 100644
--- a/pandas/tests/indexing/test_coercion.py
+++ b/pandas/tests/indexing/test_coercion.py
@@ -13,6 +13,7 @@
     IS64,
     is_platform_windows,
 )
+from pandas.compat.numpy import np_version_gt2
 
 import pandas as pd
 import pandas._testing as tm
@@ -238,7 +239,7 @@ def test_insert_float_index(
         obj = pd.Index([1.0, 2.0, 3.0, 4.0], dtype=dtype)
         coerced_dtype = coerced_dtype if coerced_dtype is not None else dtype
 
-        if dtype == "float32" and coerced_val == 1.1:
+        if np_version_gt2 and dtype == "float32" and coerced_val == 1.1:
             # Hack, in the 2nd test case, since 1.1 can be losslessly cast to float32
             # the expected dtype will be float32 if the original dtype was float32
             coerced_dtype = np.float32
diff --git a/pandas/tests/series/test_constructors.py b/pandas/tests/series/test_constructors.py
index 326c144b1e207..ea5e30084b272 100644
--- a/pandas/tests/series/test_constructors.py
+++ b/pandas/tests/series/test_constructors.py
@@ -775,16 +775,11 @@ def test_constructor_cast(self):
 
     def test_constructor_signed_int_overflow_raises(self):
         # GH#41734 disallow silent overflow, enforced in 2.0
-        if np_version_gt2:
-            msg = "The elements provided in the data cannot all be casted to the dtype"
-            err = OverflowError
-        else:
-            msg = "Values are too large to be losslessly converted"
-            err = OverflowError
-        with pytest.raises(err, match=msg):
+        msg = "The elements provided in the data cannot all be casted to the dtype"
+        with pytest.raises(OverflowError, match=msg):
             Series([1, 200, 923442], dtype="int8")
 
-        with pytest.raises(err, match=msg):
+        with pytest.raises(OverflowError, match=msg):
             Series([1, 200, 923442], dtype="uint8")
 
     @pytest.mark.parametrize(

From a12cad9216e788d9e21c33ab3e9d31e5ac417758 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Mon, 27 Nov 2023 19:42:24 -0500
Subject: [PATCH 18/27] fixes

---
 pandas/tests/series/test_constructors.py | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/pandas/tests/series/test_constructors.py b/pandas/tests/series/test_constructors.py
index ea5e30084b272..6344fa0912ed8 100644
--- a/pandas/tests/series/test_constructors.py
+++ b/pandas/tests/series/test_constructors.py
@@ -775,11 +775,16 @@ def test_constructor_cast(self):
 
     def test_constructor_signed_int_overflow_raises(self):
         # GH#41734 disallow silent overflow, enforced in 2.0
-        msg = "The elements provided in the data cannot all be casted to the dtype"
-        with pytest.raises(OverflowError, match=msg):
+        if np_version_gt2:
+            msg = "The elements provided in the data cannot all be casted to the dtype"
+            err = OverflowError
+        else:
+            msg = "Values are too large to be losslessly converted"
+            err = ValueError
+        with pytest.raises(err, match=msg):
             Series([1, 200, 923442], dtype="int8")
 
-        with pytest.raises(OverflowError, match=msg):
+        with pytest.raises(err, match=msg):
             Series([1, 200, 923442], dtype="uint8")
 
     @pytest.mark.parametrize(
@@ -1176,10 +1181,9 @@ def test_constructor_with_datetime_tz3(self):
 
     def test_constructor_with_datetime_tz2(self):
         # with all NaT
-        ser = Series(NaT, index=[0, 1], dtype="datetime64[ns, US/Eastern]")
-        dti = DatetimeIndex(["NaT", "NaT"], tz="US/Eastern").as_unit("ns")
-        expected = Series(dti)
-        tm.assert_series_equal(ser, expected)
+        s = Series(NaT, index=[0, 1], dtype="datetime64[ns, US/Eastern]")
+        expected = Series(DatetimeIndex(["NaT", "NaT"], tz="US/Eastern"))
+        tm.assert_series_equal(s, expected)
 
     def test_constructor_no_partial_datetime_casting(self):
         # GH#40111

From 1cd5acd5bf2d12b80344494c30885f6a2d54ed00 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Mon, 4 Dec 2023 16:58:59 -0500
Subject: [PATCH 19/27] adjust xfail condition

---
 pandas/tests/series/indexing/test_setitem.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/pandas/tests/series/indexing/test_setitem.py b/pandas/tests/series/indexing/test_setitem.py
index 4e6e75024e490..23137f0975fb1 100644
--- a/pandas/tests/series/indexing/test_setitem.py
+++ b/pandas/tests/series/indexing/test_setitem.py
@@ -1441,7 +1441,10 @@ def obj(self):
             np.float32,
             None,
             marks=pytest.mark.xfail(
-                np_version_gte1p24 and np._get_promotion_state() != "weak",
+                (
+                    not np_version_gte1p24
+                    or (np_version_gte1p24 and np._get_promotion_state() != "weak")
+                ),
                 reason="np.float32(1.1) ends up as 1.100000023841858, so "
                 "np_can_hold_element raises and we cast to float64",
             ),

From 42c8fff208ca4a334b8a7b9e2fe59715ab53450d Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Mon, 4 Dec 2023 17:19:43 -0500
Subject: [PATCH 20/27] go for green

---
 pandas/core/dtypes/cast.py | 5 ++++-
 pyproject.toml             | 6 +++---
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/pandas/core/dtypes/cast.py b/pandas/core/dtypes/cast.py
index 42c020c5b81cf..ab9090c5693f3 100644
--- a/pandas/core/dtypes/cast.py
+++ b/pandas/core/dtypes/cast.py
@@ -1333,7 +1333,10 @@ def find_result_type(left_dtype: DtypeObj, right: Any) -> DtypeObj:
             right_dtype = np.min_scalar_type(right)
             if right > 0 and not np.issubdtype(left_dtype, np.unsignedinteger):
                 maybe_right_dtype = np.min_scalar_type(-right)
-                if right_dtype.itemsize == maybe_right_dtype.itemsize:
+                if (
+                    maybe_right_dtype != np.dtype("O")
+                    and right_dtype.itemsize == maybe_right_dtype.itemsize
+                ):
                     # It can fit in the corresponding int version
                     right = maybe_right_dtype
                 else:
diff --git a/pyproject.toml b/pyproject.toml
index f6ba25f448540..8036825399b61 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -30,9 +30,9 @@ authors = [
 license = {file = 'LICENSE'}
 requires-python = '>=3.9'
 dependencies = [
-  "numpy>=1.22.4,<2; python_version<'3.11'",
-  "numpy>=1.23.2,<2; python_version=='3.11'",
-  "numpy>=1.26.0,<2; python_version>='3.12'",
+  "numpy>=1.22.4; python_version<'3.11'",
+  "numpy>=1.23.2; python_version=='3.11'",
+  "numpy>=1.26.0; python_version>='3.12'",
   "python-dateutil>=2.8.2",
   "pytz>=2020.1",
   "tzdata>=2022.7"

From f79bc66644cd01139beccfd07921cc7e75ca1cf5 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Tue, 19 Dec 2023 20:14:24 -0800
Subject: [PATCH 21/27] add tests

---
 pandas/core/dtypes/cast.py            | 14 +++++---
 pandas/tests/dtypes/test_inference.py | 48 +++++++++++++++++++++++++++
 pandas/tests/indexing/test_loc.py     |  2 +-
 3 files changed, 58 insertions(+), 6 deletions(-)

diff --git a/pandas/core/dtypes/cast.py b/pandas/core/dtypes/cast.py
index 3833379b75b72..6f1c9a8d79c1b 100644
--- a/pandas/core/dtypes/cast.py
+++ b/pandas/core/dtypes/cast.py
@@ -1322,14 +1322,18 @@ def find_result_type(left_dtype: DtypeObj, right: Any) -> DtypeObj:
             # This gives an unsigned type by default
             # (if our number is positive)
 
-            # If our left dtype is unsigned, we might not want this since
+            # If our left dtype is signed, we might not want this since
             # this might give us 1 dtype too big, though.
-            # W should check if the corresponding int dtype (e.g. int64 for uint64)
-            # can hold the number by a little hack where
-            # we take the negative of the number
+            # We should check if the corresponding int dtype (e.g. int64 for uint64)
+            # can hold the number by a little hack where we ask numpy for the min
+            # type of the negative of the number (which can't return an unsigned)
             # If the dtype is the same size, then we will use that
             right_dtype = np.min_scalar_type(right)
-            if right > 0 and not np.issubdtype(left_dtype, np.unsignedinteger):
+            if right == 0:
+                # Special case 0, our trick will not work for it since
+                # np.min_scalar_type(-0) will still give something unsigned
+                right = left_dtype
+            elif right > 0 and not np.issubdtype(left_dtype, np.unsignedinteger):
                 maybe_right_dtype = np.min_scalar_type(-right)
                 if (
                     maybe_right_dtype != np.dtype("O")
diff --git a/pandas/tests/dtypes/test_inference.py b/pandas/tests/dtypes/test_inference.py
index ff2cfc1278331..597a9760c33bf 100644
--- a/pandas/tests/dtypes/test_inference.py
+++ b/pandas/tests/dtypes/test_inference.py
@@ -33,8 +33,10 @@
     missing as libmissing,
     ops as libops,
 )
+from pandas.compat.numpy import np_version_gt2
 
 from pandas.core.dtypes import inference
+from pandas.core.dtypes.cast import find_result_type
 from pandas.core.dtypes.common import (
     ensure_int32,
     is_bool,
@@ -1995,3 +1997,49 @@ def test_ensure_int32():
     values = np.arange(10, dtype=np.int64)
     result = ensure_int32(values)
     assert result.dtype == np.int32
+
+
+@pytest.mark.parametrize(
+    "right,result",
+    [
+        (0, np.uint8),
+        (300, np.uint16),
+        # For floats, we just upcast directly to float64 instead of trying to
+        # find a smaller floating dtype
+        (300.0, np.uint16),  # for integer floats, we convert them to ints
+        (300.1, np.float64),
+        (np.int16(300), np.int16 if np_version_gt2 else np.uint16),
+    ],
+)
+def test_find_result_type_uint_int(right, result):
+    left_dtype = np.dtype("uint8")
+    assert find_result_type(left_dtype, right) == result
+
+
+@pytest.mark.parametrize(
+    "right,result",
+    [
+        (0, np.int8),
+        (300, np.int16),
+        # For floats, we just upcast directly to float64 instead of trying to
+        # find a smaller floating dtype
+        (300.0, np.int16),  # for integer floats, we convert them to ints
+        (300.1, np.float64),
+        (np.int16(300), np.int16),
+    ],
+)
+def test_find_result_type_int_int(right, result):
+    left_dtype = np.dtype("int8")
+    assert find_result_type(left_dtype, right) == result
+
+
+@pytest.mark.parametrize(
+    "right,result",
+    [
+        (300.0, np.float64),
+        (np.float32(300), np.float32 if np_version_gt2 else np.float16),
+    ],
+)
+def test_find_result_type_floats(right, result):
+    left_dtype = np.dtype("float16")
+    assert find_result_type(left_dtype, right) == result
diff --git a/pandas/tests/indexing/test_loc.py b/pandas/tests/indexing/test_loc.py
index 83a10ce4a0fdb..fb0adc56c401b 100644
--- a/pandas/tests/indexing/test_loc.py
+++ b/pandas/tests/indexing/test_loc.py
@@ -3022,7 +3022,7 @@ def test_loc_setitem_uint8_upcast(value):
         df.loc[2, "col1"] = value  # value that can't be held in uint8
 
     if np_version_gt2 and isinstance(value, np.int16):
-        # Note, result type of uint16 + int16 is int16
+        # Note, result type of uint8 + int16 is int16
         # in numpy < 2, though, numpy would inspect the
         # value and see that it could fit in an uint16, resulting in a uint16
         dtype = "int16"

From d7ac45284103be0a22ead2d3c9964568313df1b4 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Tue, 19 Dec 2023 20:15:41 -0800
Subject: [PATCH 22/27] add negative numbers test

---
 pandas/tests/dtypes/test_inference.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pandas/tests/dtypes/test_inference.py b/pandas/tests/dtypes/test_inference.py
index 597a9760c33bf..1e95b77ef9792 100644
--- a/pandas/tests/dtypes/test_inference.py
+++ b/pandas/tests/dtypes/test_inference.py
@@ -2003,6 +2003,7 @@ def test_ensure_int32():
     "right,result",
     [
         (0, np.uint8),
+        (-1, np.int16),
         (300, np.uint16),
         # For floats, we just upcast directly to float64 instead of trying to
         # find a smaller floating dtype
@@ -2020,6 +2021,7 @@ def test_find_result_type_uint_int(right, result):
     "right,result",
     [
         (0, np.int8),
+        (-1, np.int8),
         (300, np.int16),
         # For floats, we just upcast directly to float64 instead of trying to
         # find a smaller floating dtype

From 0d80c1c9037aeff945fa1986c0179b41b6f5238f Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Wed, 20 Dec 2023 14:15:35 -0800
Subject: [PATCH 23/27] updates

---
 pandas/_libs/tslibs/timedeltas.pyx    | 4 ++--
 pandas/tests/dtypes/test_inference.py | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/pandas/_libs/tslibs/timedeltas.pyx b/pandas/_libs/tslibs/timedeltas.pyx
index 4d7839e93f0c3..75c1d50d0b9e2 100644
--- a/pandas/_libs/tslibs/timedeltas.pyx
+++ b/pandas/_libs/tslibs/timedeltas.pyx
@@ -2122,9 +2122,9 @@ class Timedelta(_Timedelta):
                 return NaT
             # We want NumPy numeric scalars to behave like Python scalars
             # post NEP 50
-            if isinstance(other, np.integer):
+            if isinstance(other, cnp.integer):
                 other = int(other)
-            if isinstance(other, np.floating):
+            if isinstance(other, cnp.floating):
                 other = float(other)
             return type(self)._from_value_and_reso(self._value// other, self._creso)
 
diff --git a/pandas/tests/dtypes/test_inference.py b/pandas/tests/dtypes/test_inference.py
index 1e95b77ef9792..49eb06c299886 100644
--- a/pandas/tests/dtypes/test_inference.py
+++ b/pandas/tests/dtypes/test_inference.py
@@ -2039,7 +2039,7 @@ def test_find_result_type_int_int(right, result):
     "right,result",
     [
         (300.0, np.float64),
-        (np.float32(300), np.float32 if np_version_gt2 else np.float16),
+        (np.float32(300), np.float32),
     ],
 )
 def test_find_result_type_floats(right, result):

From 399bdf06474a6921c2f1c8086e4b29c1f3362e46 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Wed, 20 Dec 2023 14:18:21 -0800
Subject: [PATCH 24/27] fix accidental changes

---
 pandas/tests/series/test_constructors.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/pandas/tests/series/test_constructors.py b/pandas/tests/series/test_constructors.py
index eb376b3af3781..63efca61f98fe 100644
--- a/pandas/tests/series/test_constructors.py
+++ b/pandas/tests/series/test_constructors.py
@@ -1180,9 +1180,10 @@ def test_constructor_with_datetime_tz3(self):
 
     def test_constructor_with_datetime_tz2(self):
         # with all NaT
-        s = Series(NaT, index=[0, 1], dtype="datetime64[ns, US/Eastern]")
-        expected = Series(DatetimeIndex(["NaT", "NaT"], tz="US/Eastern"))
-        tm.assert_series_equal(s, expected)
+        ser = Series(NaT, index=[0, 1], dtype="datetime64[ns, US/Eastern]")
+        dti = DatetimeIndex(["NaT", "NaT"], tz="US/Eastern").as_unit("ns")
+        expected = Series(dti)
+        tm.assert_series_equal(ser, expected)
 
     def test_constructor_no_partial_datetime_casting(self):
         # GH#40111

From b50c6de8f335d40eb3c218fde67ccc54bfa78bc7 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Wed, 20 Dec 2023 15:56:24 -0800
Subject: [PATCH 25/27] more

---
 pandas/_libs/tslibs/timedeltas.pyx | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/_libs/tslibs/timedeltas.pyx b/pandas/_libs/tslibs/timedeltas.pyx
index 75c1d50d0b9e2..f6c69cf6d3875 100644
--- a/pandas/_libs/tslibs/timedeltas.pyx
+++ b/pandas/_libs/tslibs/timedeltas.pyx
@@ -2062,9 +2062,9 @@ class Timedelta(_Timedelta):
                 return NaT
             # We want NumPy numeric scalars to behave like Python scalars
             # post NEP 50
-            if isinstance(other, np.integer):
+            if isinstance(other, cnp.integer):
                 other = int(other)
-            if isinstance(other, np.floating):
+            if isinstance(other, cnp.floating):
                 other = float(other)
             return Timedelta._from_value_and_reso(
                 <int64_t>(self._value/ other), self._creso

From 79f4dde6f545f382a5065a4c36e392957a362ad1 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Thu, 21 Dec 2023 11:10:42 -0800
Subject: [PATCH 26/27] simplify

---
 pandas/core/dtypes/cast.py | 26 ++++++++++----------------
 1 file changed, 10 insertions(+), 16 deletions(-)

diff --git a/pandas/core/dtypes/cast.py b/pandas/core/dtypes/cast.py
index 6f1c9a8d79c1b..018d6df346492 100644
--- a/pandas/core/dtypes/cast.py
+++ b/pandas/core/dtypes/cast.py
@@ -1323,26 +1323,20 @@ def find_result_type(left_dtype: DtypeObj, right: Any) -> DtypeObj:
             # (if our number is positive)
 
             # If our left dtype is signed, we might not want this since
-            # this might give us 1 dtype too big, though.
+            # this might give us 1 dtype too big
             # We should check if the corresponding int dtype (e.g. int64 for uint64)
-            # can hold the number by a little hack where we ask numpy for the min
-            # type of the negative of the number (which can't return an unsigned)
-            # If the dtype is the same size, then we will use that
+            # can hold the number
             right_dtype = np.min_scalar_type(right)
             if right == 0:
-                # Special case 0, our trick will not work for it since
-                # np.min_scalar_type(-0) will still give something unsigned
+                # Special case 0
                 right = left_dtype
-            elif right > 0 and not np.issubdtype(left_dtype, np.unsignedinteger):
-                maybe_right_dtype = np.min_scalar_type(-right)
-                if (
-                    maybe_right_dtype != np.dtype("O")
-                    and right_dtype.itemsize == maybe_right_dtype.itemsize
-                ):
-                    # It can fit in the corresponding int version
-                    right = maybe_right_dtype
-                else:
-                    right = right_dtype
+            elif (
+                not np.issubdtype(left_dtype, np.unsignedinteger)
+                and right > 0
+                and right <= 2 ** (8 * right_dtype.itemsize - 1) - 1
+            ):
+                # If left dtype isn't unsigned, check if it fits in the signed dtype
+                right = np.dtype(f"i{right_dtype.itemsize}")
             else:
                 right = right_dtype
 

From 9ce828b16f4c43e73c40c09984d59f4d1ff95c85 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Thu, 21 Dec 2023 11:41:15 -0800
Subject: [PATCH 27/27] linter

---
 pandas/core/dtypes/cast.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/pandas/core/dtypes/cast.py b/pandas/core/dtypes/cast.py
index 018d6df346492..7a088bf84c48e 100644
--- a/pandas/core/dtypes/cast.py
+++ b/pandas/core/dtypes/cast.py
@@ -1332,8 +1332,7 @@ def find_result_type(left_dtype: DtypeObj, right: Any) -> DtypeObj:
                 right = left_dtype
             elif (
                 not np.issubdtype(left_dtype, np.unsignedinteger)
-                and right > 0
-                and right <= 2 ** (8 * right_dtype.itemsize - 1) - 1
+                and 0 < right <= 2 ** (8 * right_dtype.itemsize - 1) - 1
             ):
                 # If left dtype isn't unsigned, check if it fits in the signed dtype
                 right = np.dtype(f"i{right_dtype.itemsize}")