From ef0f67662cdb8e18a0c45061f5e4d798ac265f5a Mon Sep 17 00:00:00 2001
From: Bradley Dice <bdice@bradleydice.com>
Date: Fri, 26 Aug 2022 05:47:39 -0500
Subject: [PATCH] Raise on __eq__ binary operations between unsupported types.

---
 python/cudf/cudf/core/mixins/binops.py        | 22 +++++++++++++++++--
 python/cudf/cudf/core/mixins/mixin_factory.py |  5 ++---
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/python/cudf/cudf/core/mixins/binops.py b/python/cudf/cudf/core/mixins/binops.py
index eaabc00f266..282007135d7 100644
--- a/python/cudf/cudf/core/mixins/binops.py
+++ b/python/cudf/cudf/core/mixins/binops.py
@@ -1,6 +1,6 @@
 # Copyright (c) 2022, NVIDIA CORPORATION.
 
-from .mixin_factory import _create_delegating_mixin
+from .mixin_factory import Operation, _create_delegating_mixin
 
 BinaryOperand = _create_delegating_mixin(
     "BinaryOperand",
@@ -59,7 +59,17 @@ def _binaryop(self, other, op: str):
     Must be overridden by subclasses, the default implementation raises a
     NotImplementedError.
     """
-    raise NotImplementedError
+    if op == "__eq__":
+        raise TypeError(
+            "'==' not supported between instances of "
+            f"'{type(self).__name__}' and '{type(other).__name__}'"
+        )
+    if op == "__ne__":
+        raise TypeError(
+            "'!=' not supported between instances of "
+            f"'{type(self).__name__}' and '{type(other).__name__}'"
+        )
+    raise NotImplementedError()
 
 
 def _check_reflected_op(op):
@@ -70,3 +80,11 @@ def _check_reflected_op(op):
 
 BinaryOperand._binaryop = _binaryop
 BinaryOperand._check_reflected_op = staticmethod(_check_reflected_op)
+
+# It is necessary to override the default object.__eq__ so that objects don't
+# automatically support equality binops using the wrong operator implementation
+# (falling back to ``object``). We must override the object.__eq__ with an
+# Operation rather than a plain function/method, so that the BinaryOperand
+# mixin overrides it for classes that define their own __eq__ in _binaryop.
+BinaryOperand.__eq__ = Operation("__eq__", {}, BinaryOperand._binaryop)
+BinaryOperand.__ne__ = Operation("__ne__", {}, BinaryOperand._binaryop)
diff --git a/python/cudf/cudf/core/mixins/mixin_factory.py b/python/cudf/cudf/core/mixins/mixin_factory.py
index 7bbb299d643..e3564bf4dc6 100644
--- a/python/cudf/cudf/core/mixins/mixin_factory.py
+++ b/python/cudf/cudf/core/mixins/mixin_factory.py
@@ -27,9 +27,8 @@ class Operation:
     ----------
     name : str
         The name of the operation.
-    docstring_format_args : str
-        The attribute of the owning class from which to pull format parameters
-        for this operation's docstring.
+    docstring_format_args : dict
+        The dict of format parameters for this operation's docstring.
     base_operation : str
         The underlying operation function to be invoked when operation `name`
         is called on the owning class.