Clean-up functools.total_ordering().

Lib/functools.py

@@ -65,7 +65,6 @@ def wraps(wrapped,
     return partial(update_wrapper, wrapped=wrapped,
                    assigned=assigned, updated=updated)
 
-_object_defaults = {object.__lt__, object.__le__, object.__gt__, object.__ge__}
 def total_ordering(cls):
     """Class decorator that fills in missing ordering methods"""
     convert = {
@@ -82,9 +81,8 @@ def total_ordering(cls):
                    ('__gt__', lambda self, other: not other >= self),
                    ('__lt__', lambda self, other: not self >= other)]
     }
-    roots = set(dir(cls)) & set(convert)
+    # Find comparisons not inherited from object.
-    # Remove default comparison operations defined on object.
+    roots = [op for op in convert if getattr(cls, op) is not getattr(object, op)]
-    roots -= {meth for meth in roots if getattr(cls, meth) in _object_defaults}
     if not roots:
         raise ValueError('must define at least one ordering operation: < > <= >=')
     root = max(roots)       # prefer __lt__ to __le__ to __gt__ to __ge__

Misc/NEWS

@@ -222,7 +222,7 @@ Library
 
 - Issue #9501: Fixed logging regressions in cleanup code.
 
-- Fix functools.total_ordering() to actually work.
+- Fix functools.total_ordering() to skip methods inherited from object().
 
 - Issue #9572: Importlib should not raise an exception if a directory it
   thought it needed to create was done concurrently by another process.