Issue #24206: Fixed __eq__ and __ne__ methods of inspect classes.

3 files changed, 66 insertions, 38 deletions

diff --git a/Lib/inspect.py b/Lib/inspect.py
index 49e66ce078..4298de6b60 100644
--- a/Lib/inspect.py
+++ b/Lib/inspect.py
@@ -2206,15 +2206,13 @@ class Parameter:
                                            id(self), self.name)
 
     def __eq__(self, other):
-        return (issubclass(other.__class__, Parameter) and
-                self._name == other._name and
+        if not isinstance(other, Parameter):
+            return NotImplemented
+        return (self._name == other._name and
                 self._kind == other._kind and
                 self._default == other._default and
                 self._annotation == other._annotation)
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
 
 class BoundArguments:
     '''Result of `Signature.bind` call.  Holds the mapping of arguments
@@ -2295,13 +2293,11 @@ class BoundArguments:
         return kwargs
 
     def __eq__(self, other):
-        return (issubclass(other.__class__, BoundArguments) and
-                self.signature == other.signature and
+        if not isinstance(other, BoundArguments):
+            return NotImplemented
+        return (self.signature == other.signature and
                 self.arguments == other.arguments)
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
 
 class Signature:
     '''A Signature object represents the overall signature of a function.
@@ -2493,9 +2489,10 @@ class Signature:
                           return_annotation=return_annotation)
 
     def __eq__(self, other):
-        if (not issubclass(type(other), Signature) or
-                    self.return_annotation != other.return_annotation or
-                    len(self.parameters) != len(other.parameters)):
+        if not isinstance(other, Signature):
+            return NotImplemented
+        if (self.return_annotation != other.return_annotation or
+            len(self.parameters) != len(other.parameters)):
             return False
 
         other_positions = {param: idx
@@ -2522,9 +2519,6 @@ class Signature:
 
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
     def _bind(self, args, kwargs, *, partial=False):
         '''Private method.  Don't use directly.'''
 
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index 58a6cd2c56..1a124b5db2 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -76,6 +76,10 @@ def generator_function_example(self):
     for i in range(2):
         yield i
 
+class EqualsToAll:
+    def __eq__(self, other):
+        return True
+
 class TestPredicates(IsTestBase):
     def test_sixteen(self):
         count = len([x for x in dir(inspect) if x.startswith('is')])
@@ -2459,47 +2463,62 @@ class TestSignatureObject(unittest.TestCase):
 
     def test_signature_equality(self):
         def foo(a, *, b:int) -> float: pass
-        self.assertNotEqual(inspect.signature(foo), 42)
+        self.assertFalse(inspect.signature(foo) == 42)
+        self.assertTrue(inspect.signature(foo) != 42)
+        self.assertTrue(inspect.signature(foo) == EqualsToAll())
+        self.assertFalse(inspect.signature(foo) != EqualsToAll())
 
         def bar(a, *, b:int) -> float: pass
-        self.assertEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertTrue(inspect.signature(foo) == inspect.signature(bar))
+        self.assertFalse(inspect.signature(foo) != inspect.signature(bar))
 
         def bar(a, *, b:int) -> int: pass
-        self.assertNotEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertFalse(inspect.signature(foo) == inspect.signature(bar))
+        self.assertTrue(inspect.signature(foo) != inspect.signature(bar))
 
         def bar(a, *, b:int): pass
-        self.assertNotEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertFalse(inspect.signature(foo) == inspect.signature(bar))
+        self.assertTrue(inspect.signature(foo) != inspect.signature(bar))
 
         def bar(a, *, b:int=42) -> float: pass
-        self.assertNotEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertFalse(inspect.signature(foo) == inspect.signature(bar))
+        self.assertTrue(inspect.signature(foo) != inspect.signature(bar))
 
         def bar(a, *, c) -> float: pass
-        self.assertNotEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertFalse(inspect.signature(foo) == inspect.signature(bar))
+        self.assertTrue(inspect.signature(foo) != inspect.signature(bar))
 
         def bar(a, b:int) -> float: pass
-        self.assertNotEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertFalse(inspect.signature(foo) == inspect.signature(bar))
+        self.assertTrue(inspect.signature(foo) != inspect.signature(bar))
         def spam(b:int, a) -> float: pass
-        self.assertNotEqual(inspect.signature(spam), inspect.signature(bar))
+        self.assertFalse(inspect.signature(spam) == inspect.signature(bar))
+        self.assertTrue(inspect.signature(spam) != inspect.signature(bar))
 
         def foo(*, a, b, c): pass
         def bar(*, c, b, a): pass
-        self.assertEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertTrue(inspect.signature(foo) == inspect.signature(bar))
+        self.assertFalse(inspect.signature(foo) != inspect.signature(bar))
 
         def foo(*, a=1, b, c): pass
         def bar(*, c, b, a=1): pass
-        self.assertEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertTrue(inspect.signature(foo) == inspect.signature(bar))
+        self.assertFalse(inspect.signature(foo) != inspect.signature(bar))
 
         def foo(pos, *, a=1, b, c): pass
         def bar(pos, *, c, b, a=1): pass
-        self.assertEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertTrue(inspect.signature(foo) == inspect.signature(bar))
+        self.assertFalse(inspect.signature(foo) != inspect.signature(bar))
 
         def foo(pos, *, a, b, c): pass
         def bar(pos, *, c, b, a=1): pass
-        self.assertNotEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertFalse(inspect.signature(foo) == inspect.signature(bar))
+        self.assertTrue(inspect.signature(foo) != inspect.signature(bar))
 
         def foo(pos, *args, a=42, b, c, **kwargs:int): pass
         def bar(pos, *args, c, b, a=42, **kwargs:int): pass
-        self.assertEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertTrue(inspect.signature(foo) == inspect.signature(bar))
+        self.assertFalse(inspect.signature(foo) != inspect.signature(bar))
 
     def test_signature_unhashable(self):
         def foo(a): pass
@@ -2629,11 +2648,17 @@ class TestParameterObject(unittest.TestCase):
         P = inspect.Parameter
         p = P('foo', default=42, kind=inspect.Parameter.KEYWORD_ONLY)
 
-        self.assertEqual(p, p)
-        self.assertNotEqual(p, 42)
+        self.assertTrue(p == p)
+        self.assertFalse(p != p)
+        self.assertFalse(p == 42)
+        self.assertTrue(p != 42)
+        self.assertTrue(p == EqualsToAll())
+        self.assertFalse(p != EqualsToAll())
 
-        self.assertEqual(p, P('foo', default=42,
-                              kind=inspect.Parameter.KEYWORD_ONLY))
+        self.assertTrue(p == P('foo', default=42,
+                               kind=inspect.Parameter.KEYWORD_ONLY))
+        self.assertFalse(p != P('foo', default=42,
+                                kind=inspect.Parameter.KEYWORD_ONLY))
 
     def test_signature_parameter_unhashable(self):
         p = inspect.Parameter('foo', default=42,
@@ -2936,19 +2961,26 @@ class TestBoundArguments(unittest.TestCase):
     def test_signature_bound_arguments_equality(self):
         def foo(a): pass
         ba = inspect.signature(foo).bind(1)
-        self.assertEqual(ba, ba)
+        self.assertTrue(ba == ba)
+        self.assertFalse(ba != ba)
+        self.assertTrue(ba == EqualsToAll())
+        self.assertFalse(ba != EqualsToAll())
 
         ba2 = inspect.signature(foo).bind(1)
-        self.assertEqual(ba, ba2)
+        self.assertTrue(ba == ba2)
+        self.assertFalse(ba != ba2)
 
         ba3 = inspect.signature(foo).bind(2)
-        self.assertNotEqual(ba, ba3)
+        self.assertFalse(ba == ba3)
+        self.assertTrue(ba != ba3)
         ba3.arguments['a'] = 1
-        self.assertEqual(ba, ba3)
+        self.assertTrue(ba == ba3)
+        self.assertFalse(ba != ba3)
 
         def bar(b): pass
         ba4 = inspect.signature(bar).bind(1)
-        self.assertNotEqual(ba, ba4)
+        self.assertFalse(ba == ba4)
+        self.assertTrue(ba != ba4)
 
 
 class TestSignaturePrivateHelpers(unittest.TestCase):
diff --git a/Misc/NEWS b/Misc/NEWS
index 2c669f3bbb..ad5fef33fa 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -66,6 +66,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #24206: Fixed __eq__ and __ne__ methods of inspect classes.
+
 - Issue #21750: mock_open.read_data can now be read from each instance, as it
   could in Python 3.3.