From 0f6c1e2a69315523aafeb25716323f11e5e36f97 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 8 Nov 2023 16:34:22 -0800
Subject: [PATCH 1/4] Ensure slow private attrs are maybe proxies

---
 python/cudf/cudf/pandas/fast_slow_proxy.py | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/python/cudf/cudf/pandas/fast_slow_proxy.py b/python/cudf/cudf/pandas/fast_slow_proxy.py
index 3dc6a59cc16..cbc4b7a6616 100644
--- a/python/cudf/cudf/pandas/fast_slow_proxy.py
+++ b/python/cudf/cudf/pandas/fast_slow_proxy.py
@@ -584,7 +584,24 @@ def __getattr__(self, name: str) -> Any:
             _raise_attribute_error(self.__class__.__name__, name)
         if name.startswith("_"):
             # private attributes always come from `._fsproxy_slow`:
-            return getattr(self._fsproxy_slow, name)
+            obj = getattr(self._fsproxy_slow, name)
+            if name.startswith("__array"):
+                # TODO: numpy methods raise when given proxy ndarray objects
+                # https://numpy.org/doc/stable/reference/arrays.classes.html#special-attributes-and-methods  # noqa:E501
+                return obj
+
+            if not _is_function_or_method(obj):
+                return _maybe_wrap_result(
+                    obj, getattr, self._fsproxy_slow, name
+                )
+
+            @functools.wraps(obj)
+            def _wrapped_private_slow(*args, **kwargs):
+                slow_args, slow_kwargs = _slow_arg(args), _slow_arg(kwargs)
+                result = obj(*slow_args, **slow_kwargs)
+                return _maybe_wrap_result(result, obj, *args, **kwargs)
+
+            return _wrapped_private_slow
         attr = _FastSlowAttribute(name)
         return attr.__get__(self)
 

From ab0fa8cbce7f3736a40709caaf043cf53e48ed8c Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 8 Nov 2023 16:38:15 -0800
Subject: [PATCH 2/4] Ensure slow private attrs are maybe proxies

---
 .../cudf_pandas_tests/test_cudf_pandas.py     |  7 +++++
 .../cudf_pandas_tests/test_fast_slow_proxy.py | 29 +++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/python/cudf/cudf_pandas_tests/test_cudf_pandas.py b/python/cudf/cudf_pandas_tests/test_cudf_pandas.py
index 2500ba07bd9..0ba489ab4b1 100644
--- a/python/cudf/cudf_pandas_tests/test_cudf_pandas.py
+++ b/python/cudf/cudf_pandas_tests/test_cudf_pandas.py
@@ -1103,6 +1103,13 @@ def test_dataframe_query():
     tm.assert_equal(actual, expected)
 
 
+def test_private_method_result_wrapped():
+    xoffset = xpd.offsets.Day()
+    dt = datetime.datetime(2020, 1, 1)
+    result = xoffset._apply(dt)
+    assert type(result) is xpd.Timestamp
+
+
 def test_numpy_var():
     np.random.seed(42)
     data = np.random.rand(1000)
diff --git a/python/cudf/cudf_pandas_tests/test_fast_slow_proxy.py b/python/cudf/cudf_pandas_tests/test_fast_slow_proxy.py
index b964dfde4ed..b78d290e3ff 100644
--- a/python/cudf/cudf_pandas_tests/test_fast_slow_proxy.py
+++ b/python/cudf/cudf_pandas_tests/test_fast_slow_proxy.py
@@ -445,6 +445,35 @@ def __radd__(self, other):
     assert BarProxy() + Foo() == "sum"
 
 
+def test_slow_attr_still_proxy():
+    class A:
+        pass
+
+    class B:
+        @property
+        def _private(self):
+            return A()
+
+    pxy_a = make_final_proxy_type(
+        "A",
+        _Unusable,
+        A,
+        fast_to_slow=_Unusable(),
+        slow_to_fast=_Unusable(),
+    )
+
+    pxy_b = make_final_proxy_type(
+        "B",
+        _Unusable,
+        B,
+        fast_to_slow=_Unusable(),
+        slow_to_fast=_Unusable(),
+    )
+
+    result = pxy_b()._private
+    assert isinstance(result, pxy_a)
+
+
 def tuple_with_attrs(name, fields: list[str], extra_fields: set[str]):
     # Build a tuple-like class with some extra attributes and a custom
     # pickling scheme with __getnewargs_ex__

From e53fefb5c2e092cbaac58dcb49ee9276449f32bd Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 31 Jan 2024 13:48:35 -0800
Subject: [PATCH 3/4] Add copyright

---
 python/cudf/cudf_pandas_tests/test_fast_slow_proxy.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/python/cudf/cudf_pandas_tests/test_fast_slow_proxy.py b/python/cudf/cudf_pandas_tests/test_fast_slow_proxy.py
index b78d290e3ff..631ad2f37b2 100644
--- a/python/cudf/cudf_pandas_tests/test_fast_slow_proxy.py
+++ b/python/cudf/cudf_pandas_tests/test_fast_slow_proxy.py
@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2023 NVIDIA CORPORATION & AFFILIATES.
+# SPDX-FileCopyrightText: Copyright (c) 2023-2024 NVIDIA CORPORATION & AFFILIATES.
 # All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 

From 6a36cc312a71044b163c5b9d7313f787ca86e939 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 21 Feb 2024 15:30:38 -0800
Subject: [PATCH 4/4] Update python/cudf/cudf_pandas_tests/test_cudf_pandas.py

Co-authored-by: Bradley Dice <bdice@bradleydice.com>
---
 python/cudf/cudf_pandas_tests/test_cudf_pandas.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/python/cudf/cudf_pandas_tests/test_cudf_pandas.py b/python/cudf/cudf_pandas_tests/test_cudf_pandas.py
index ac2fa8cd3f1..0386ec434da 100644
--- a/python/cudf/cudf_pandas_tests/test_cudf_pandas.py
+++ b/python/cudf/cudf_pandas_tests/test_cudf_pandas.py
@@ -1082,7 +1082,7 @@ def test_private_method_result_wrapped():
     xoffset = xpd.offsets.Day()
     dt = datetime.datetime(2020, 1, 1)
     result = xoffset._apply(dt)
-    assert type(result) is xpd.Timestamp
+    assert isinstance(result, xpd.Timestamp)
 
 
 def test_numpy_var():