add pandas debugging mode option

python/cudf/cudf/options.py

@@ -308,6 +308,21 @@ def _integer_and_none_validator(val):
     _make_contains_validator([False, True]),
 )
 
+_register_option(
+    "mode.pandas_debugging",
+    False,
+    textwrap.dedent(
+        """
+        If set to `False`, retains `cudf` specific behavior.
+        If set to `True`, enables pandas debugging mode,
+        which will raise a warning if the results from cudf
+        and pandas differ.
+        \tValid values are True or False. Default is False.
+    """
+    ),
+    _make_contains_validator([False, True]),
+)
+
 
 class option_context(ContextDecorator):
     """

python/cudf/cudf/pandas/fast_slow_proxy.py

@@ -23,6 +23,7 @@
     Type,
 )
 
+from ..options import get_option
 from .annotation import nvtx
 
 
@@ -898,6 +899,18 @@ def _fast_slow_function_call(func: Callable, /, *args, **kwargs) -> Any:
                 # try slow path
                 raise Exception()
             fast = True
+
+            if get_option("mode.pandas_debugging"):
+                with nvtx.annotate(
+                    "EXECUTE_SLOW",
+                    color=_CUDF_PANDAS_NVTX_COLORS["EXECUTE_SLOW"],
+                    domain="cudf_pandas",
+                ):
+                    slow_args, slow_kwargs = _slow_arg(args), _slow_arg(kwargs)
+                    with disable_module_accelerator():
+                        result_slow = func(*slow_args, **slow_kwargs)
+                        print(result_slow)
+                        # TODO: Compare result and result slow and return a warning
     except Exception:
         with nvtx.annotate(
             "EXECUTE_SLOW",

python/cudf/cudf_pandas_tests/test_fast_slow_proxy.py

@@ -9,7 +9,7 @@
 import numpy as np
 import pytest
 
-from cudf.pandas.fast_slow_proxy import (
+from cudf.pandas.fast_slow_proxy import (  # _fast_slow_function_call,
     _fast_arg,
     _FunctionProxy,
     _slow_arg,
@@ -545,3 +545,7 @@ def test_tuple_with_attrs_transform():
     assert b == bprime and b is not bprime
     assert c == cprime and c is not cprime
     assert d == dprime and d is not dprime
+
+
+def test_fast_slow_function_call():
+    assert True