bpo-37685: Fixed __eq__, __lt__ etc implementations in some classes. (GH-14952)

They now return NotImplemented for unsupported type of the other operand.

20 files changed, 178 insertions, 43 deletions

diff --git a/Lib/asyncio/events.py b/Lib/asyncio/events.py
index d381b1c..5fb5464 100644
--- a/Lib/asyncio/events.py
+++ b/Lib/asyncio/events.py
@@ -119,20 +119,24 @@ class TimerHandle(Handle):
         return hash(self._when)
 
     def __lt__(self, other):
-        return self._when < other._when
+        if isinstance(other, TimerHandle):
+            return self._when < other._when
+        return NotImplemented
 
     def __le__(self, other):
-        if self._when < other._when:
-            return True
-        return self.__eq__(other)
+        if isinstance(other, TimerHandle):
+            return self._when < other._when or self.__eq__(other)
+        return NotImplemented
 
     def __gt__(self, other):
-        return self._when > other._when
+        if isinstance(other, TimerHandle):
+            return self._when > other._when
+        return NotImplemented
 
     def __ge__(self, other):
-        if self._when > other._when:
-            return True
-        return self.__eq__(other)
+        if isinstance(other, TimerHandle):
+            return self._when > other._when or self.__eq__(other)
+        return NotImplemented
 
     def __eq__(self, other):
         if isinstance(other, TimerHandle):
@@ -142,10 +146,6 @@ class TimerHandle(Handle):
                     self._cancelled == other._cancelled)
         return NotImplemented
 
-    def __ne__(self, other):
-        equal = self.__eq__(other)
-        return NotImplemented if equal is NotImplemented else not equal
-
     def cancel(self):
         if not self._cancelled:
             self._loop._timer_handle_cancelled(self)
diff --git a/Lib/distutils/tests/test_version.py b/Lib/distutils/tests/test_version.py
index 15f14c7..8671cd2 100644
--- a/Lib/distutils/tests/test_version.py
+++ b/Lib/distutils/tests/test_version.py
@@ -45,6 +45,14 @@ class VersionTestCase(unittest.TestCase):
             self.assertEqual(res, wanted,
                              'cmp(%s, %s) should be %s, got %s' %
                              (v1, v2, wanted, res))
+            res = StrictVersion(v1)._cmp(v2)
+            self.assertEqual(res, wanted,
+                             'cmp(%s, %s) should be %s, got %s' %
+                             (v1, v2, wanted, res))
+            res = StrictVersion(v1)._cmp(object())
+            self.assertIs(res, NotImplemented,
+                          'cmp(%s, %s) should be NotImplemented, got %s' %
+                          (v1, v2, res))
 
 
     def test_cmp(self):
@@ -63,6 +71,14 @@ class VersionTestCase(unittest.TestCase):
             self.assertEqual(res, wanted,
                              'cmp(%s, %s) should be %s, got %s' %
                              (v1, v2, wanted, res))
+            res = LooseVersion(v1)._cmp(v2)
+            self.assertEqual(res, wanted,
+                             'cmp(%s, %s) should be %s, got %s' %
+                             (v1, v2, wanted, res))
+            res = LooseVersion(v1)._cmp(object())
+            self.assertIs(res, NotImplemented,
+                          'cmp(%s, %s) should be NotImplemented, got %s' %
+                          (v1, v2, res))
 
 def test_suite():
     return unittest.makeSuite(VersionTestCase)
diff --git a/Lib/distutils/version.py b/Lib/distutils/version.py
index af14cc1..c33beba 100644
--- a/Lib/distutils/version.py
+++ b/Lib/distutils/version.py
@@ -166,6 +166,8 @@ class StrictVersion (Version):
     def _cmp (self, other):
         if isinstance(other, str):
             other = StrictVersion(other)
+        elif not isinstance(other, StrictVersion):
+            return NotImplemented
 
         if self.version != other.version:
             # numeric versions don't match
@@ -331,6 +333,8 @@ class LooseVersion (Version):
     def _cmp (self, other):
         if isinstance(other, str):
             other = LooseVersion(other)
+        elif not isinstance(other, LooseVersion):
+            return NotImplemented
 
         if self.version == other.version:
             return 0
diff --git a/Lib/email/headerregistry.py b/Lib/email/headerregistry.py
index 8d1a202..dcc960b 100644
--- a/Lib/email/headerregistry.py
+++ b/Lib/email/headerregistry.py
@@ -97,8 +97,8 @@ class Address:
         return self.addr_spec
 
     def __eq__(self, other):
-        if type(other) != type(self):
-            return False
+        if not isinstance(other, Address):
+            return NotImplemented
         return (self.display_name == other.display_name and
                 self.username == other.username and
                 self.domain == other.domain)
@@ -150,8 +150,8 @@ class Group:
         return "{}:{};".format(disp, adrstr)
 
     def __eq__(self, other):
-        if type(other) != type(self):
-            return False
+        if not isinstance(other, Group):
+            return NotImplemented
         return (self.display_name == other.display_name and
                 self.addresses == other.addresses)
 
diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py
index 5e2f520..e17eeb6 100644
--- a/Lib/importlib/_bootstrap.py
+++ b/Lib/importlib/_bootstrap.py
@@ -371,7 +371,7 @@ class ModuleSpec:
                     self.cached == other.cached and
                     self.has_location == other.has_location)
         except AttributeError:
-            return False
+            return NotImplemented
 
     @property
     def cached(self):
diff --git a/Lib/test/test_asyncio/test_events.py b/Lib/test/test_asyncio/test_events.py
index e5ad72f..5bc1bc2 100644
--- a/Lib/test/test_asyncio/test_events.py
+++ b/Lib/test/test_asyncio/test_events.py
@@ -32,6 +32,7 @@ from asyncio import proactor_events
 from asyncio import selector_events
 from test.test_asyncio import utils as test_utils
 from test import support
+from test.support import ALWAYS_EQ, LARGEST, SMALLEST
 
 
 def tearDownModule():
@@ -2364,6 +2365,28 @@ class TimerTests(unittest.TestCase):
         self.assertIs(NotImplemented, h1.__eq__(h3))
         self.assertIs(NotImplemented, h1.__ne__(h3))
 
+        with self.assertRaises(TypeError):
+            h1 < ()
+        with self.assertRaises(TypeError):
+            h1 > ()
+        with self.assertRaises(TypeError):
+            h1 <= ()
+        with self.assertRaises(TypeError):
+            h1 >= ()
+        self.assertFalse(h1 == ())
+        self.assertTrue(h1 != ())
+
+        self.assertTrue(h1 == ALWAYS_EQ)
+        self.assertFalse(h1 != ALWAYS_EQ)
+        self.assertTrue(h1 < LARGEST)
+        self.assertFalse(h1 > LARGEST)
+        self.assertTrue(h1 <= LARGEST)
+        self.assertFalse(h1 >= LARGEST)
+        self.assertFalse(h1 < SMALLEST)
+        self.assertTrue(h1 > SMALLEST)
+        self.assertFalse(h1 <= SMALLEST)
+        self.assertTrue(h1 >= SMALLEST)
+
 
 class AbstractEventLoopTests(unittest.TestCase):
 
diff --git a/Lib/test/test_email/test_headerregistry.py b/Lib/test/test_email/test_headerregistry.py
index 5d9b357..4758f4b 100644
--- a/Lib/test/test_email/test_headerregistry.py
+++ b/Lib/test/test_email/test_headerregistry.py
@@ -7,6 +7,7 @@ from email.message import Message
 from test.test_email import TestEmailBase, parameterize
 from email import headerregistry
 from email.headerregistry import Address, Group
+from test.support import ALWAYS_EQ
 
 
 DITTO = object()
@@ -1525,6 +1526,24 @@ class TestAddressAndGroup(TestEmailBase):
         self.assertEqual(m['to'], 'foo bar:;')
         self.assertEqual(m['to'].addresses, g.addresses)
 
+    def test_address_comparison(self):
+        a = Address('foo', 'bar', 'example.com')
+        self.assertEqual(Address('foo', 'bar', 'example.com'), a)
+        self.assertNotEqual(Address('baz', 'bar', 'example.com'), a)
+        self.assertNotEqual(Address('foo', 'baz', 'example.com'), a)
+        self.assertNotEqual(Address('foo', 'bar', 'baz'), a)
+        self.assertFalse(a == object())
+        self.assertTrue(a == ALWAYS_EQ)
+
+    def test_group_comparison(self):
+        a = Address('foo', 'bar', 'example.com')
+        g = Group('foo bar', [a])
+        self.assertEqual(Group('foo bar', (a,)), g)
+        self.assertNotEqual(Group('baz', [a]), g)
+        self.assertNotEqual(Group('foo bar', []), g)
+        self.assertFalse(g == object())
+        self.assertTrue(g == ALWAYS_EQ)
+
 
 class TestFolding(TestHeaderBase):
 
diff --git a/Lib/test/test_traceback.py b/Lib/test/test_traceback.py
index 96d85e2..72dc7af 100644
--- a/Lib/test/test_traceback.py
+++ b/Lib/test/test_traceback.py
@@ -7,7 +7,7 @@ import sys
 import unittest
 import re
 from test import support
-from test.support import TESTFN, Error, captured_output, unlink, cpython_only
+from test.support import TESTFN, Error, captured_output, unlink, cpython_only, ALWAYS_EQ
 from test.support.script_helper import assert_python_ok
 import textwrap
 
@@ -887,6 +887,8 @@ class TestFrame(unittest.TestCase):
         # operator fallbacks to FrameSummary.__eq__.
         self.assertEqual(tuple(f), f)
         self.assertIsNone(f.locals)
+        self.assertNotEqual(f, object())
+        self.assertEqual(f, ALWAYS_EQ)
 
     def test_lazy_lines(self):
         linecache.clearcache()
@@ -1083,6 +1085,18 @@ class TestTracebackException(unittest.TestCase):
         self.assertEqual(exc_info[0], exc.exc_type)
         self.assertEqual(str(exc_info[1]), str(exc))
 
+    def test_comparison(self):
+        try:
+            1/0
+        except Exception:
+            exc_info = sys.exc_info()
+            exc = traceback.TracebackException(*exc_info)
+            exc2 = traceback.TracebackException(*exc_info)
+        self.assertIsNot(exc, exc2)
+        self.assertEqual(exc, exc2)
+        self.assertNotEqual(exc, object())
+        self.assertEqual(exc, ALWAYS_EQ)
+
     def test_unhashable(self):
         class UnhashableException(Exception):
             def __eq__(self, other):
diff --git a/Lib/test/test_weakref.py b/Lib/test/test_weakref.py
index ce5bbfc..41f78e7 100644
--- a/Lib/test/test_weakref.py
+++ b/Lib/test/test_weakref.py
@@ -11,7 +11,7 @@ import time
 import random
 
 from test import support
-from test.support import script_helper
+from test.support import script_helper, ALWAYS_EQ
 
 # Used in ReferencesTestCase.test_ref_created_during_del() .
 ref_from_del = None
@@ -794,6 +794,10 @@ class ReferencesTestCase(TestBase):
         self.assertTrue(a != c)
         self.assertTrue(a == d)
         self.assertFalse(a != d)
+        self.assertFalse(a == x)
+        self.assertTrue(a != x)
+        self.assertTrue(a == ALWAYS_EQ)
+        self.assertFalse(a != ALWAYS_EQ)
         del x, y, z
         gc.collect()
         for r in a, b, c:
@@ -1102,6 +1106,9 @@ class WeakMethodTestCase(unittest.TestCase):
         _ne(a, f)
         _ne(b, e)
         _ne(b, f)
+        # Compare with different types
+        _ne(a, x.some_method)
+        _eq(a, ALWAYS_EQ)
         del x, y, z
         gc.collect()
         # Dead WeakMethods compare by identity
diff --git a/Lib/test/test_xmlrpc.py b/Lib/test/test_xmlrpc.py
index 52bacc1..e5c3496 100644
--- a/Lib/test/test_xmlrpc.py
+++ b/Lib/test/test_xmlrpc.py
@@ -15,6 +15,7 @@ import re
 import io
 import contextlib
 from test import support
+from test.support import ALWAYS_EQ, LARGEST, SMALLEST
 
 try:
     import gzip
@@ -530,14 +531,10 @@ class DateTimeTestCase(unittest.TestCase):
         # some other types
         dbytes = dstr.encode('ascii')
         dtuple = now.timetuple()
-        with self.assertRaises(TypeError):
-            dtime == 1970
-        with self.assertRaises(TypeError):
-            dtime != dbytes
-        with self.assertRaises(TypeError):
-            dtime == bytearray(dbytes)
-        with self.assertRaises(TypeError):
-            dtime != dtuple
+        self.assertFalse(dtime == 1970)
+        self.assertTrue(dtime != dbytes)
+        self.assertFalse(dtime == bytearray(dbytes))
+        self.assertTrue(dtime != dtuple)
         with self.assertRaises(TypeError):
             dtime < float(1970)
         with self.assertRaises(TypeError):
@@ -547,6 +544,18 @@ class DateTimeTestCase(unittest.TestCase):
         with self.assertRaises(TypeError):
             dtime >= dtuple
 
+        self.assertTrue(dtime == ALWAYS_EQ)
+        self.assertFalse(dtime != ALWAYS_EQ)
+        self.assertTrue(dtime < LARGEST)
+        self.assertFalse(dtime > LARGEST)
+        self.assertTrue(dtime <= LARGEST)
+        self.assertFalse(dtime >= LARGEST)
+        self.assertFalse(dtime < SMALLEST)
+        self.assertTrue(dtime > SMALLEST)
+        self.assertFalse(dtime <= SMALLEST)
+        self.assertTrue(dtime >= SMALLEST)
+
+
 class BinaryTestCase(unittest.TestCase):
 
     # XXX What should str(Binary(b"\xff")) return?  I'm chosing "\xff"
diff --git a/Lib/tkinter/__init__.py b/Lib/tkinter/__init__.py
index 9626a27..9258484 100644
--- a/Lib/tkinter/__init__.py
+++ b/Lib/tkinter/__init__.py
@@ -484,6 +484,8 @@ class Variable:
         Note: if the Variable's master matters to behavior
         also compare self._master == other._master
         """
+        if not isinstance(other, Variable):
+            return NotImplemented
         return self.__class__.__name__ == other.__class__.__name__ \
             and self._name == other._name
 
diff --git a/Lib/tkinter/font.py b/Lib/tkinter/font.py
index eeff454..15ad7ab 100644
--- a/Lib/tkinter/font.py
+++ b/Lib/tkinter/font.py
@@ -101,7 +101,9 @@ class Font:
         return self.name
 
     def __eq__(self, other):
-        return isinstance(other, Font) and self.name == other.name
+        if not isinstance(other, Font):
+            return NotImplemented
+        return self.name == other.name
 
     def __getitem__(self, key):
         return self.cget(key)
diff --git a/Lib/tkinter/test/test_tkinter/test_font.py b/Lib/tkinter/test/test_tkinter/test_font.py
index 97cd87c..a021ea3 100644
--- a/Lib/tkinter/test/test_tkinter/test_font.py
+++ b/Lib/tkinter/test/test_tkinter/test_font.py
@@ -1,7 +1,7 @@
 import unittest
 import tkinter
 from tkinter import font
-from test.support import requires, run_unittest, gc_collect
+from test.support import requires, run_unittest, gc_collect, ALWAYS_EQ
 from tkinter.test.support import AbstractTkTest
 
 requires('gui')
@@ -70,6 +70,7 @@ class FontTest(AbstractTkTest, unittest.TestCase):
         self.assertEqual(font1, font2)
         self.assertNotEqual(font1, font1.copy())
         self.assertNotEqual(font1, 0)
+        self.assertEqual(font1, ALWAYS_EQ)
 
     def test_measure(self):
         self.assertIsInstance(self.font.measure('abc'), int)
diff --git a/Lib/tkinter/test/test_tkinter/test_variables.py b/Lib/tkinter/test/test_tkinter/test_variables.py
index 2eb1e12..08b7ded 100644
--- a/Lib/tkinter/test/test_tkinter/test_variables.py
+++ b/Lib/tkinter/test/test_tkinter/test_variables.py
@@ -2,6 +2,7 @@ import unittest
 import gc
 from tkinter import (Variable, StringVar, IntVar, DoubleVar, BooleanVar, Tcl,
                      TclError)
+from test.support import ALWAYS_EQ
 
 
 class Var(Variable):
@@ -59,11 +60,17 @@ class TestVariable(TestBase):
         # values doesn't matter, only class and name are checked
         v1 = Variable(self.root, name="abc")
         v2 = Variable(self.root, name="abc")
+        self.assertIsNot(v1, v2)
         self.assertEqual(v1, v2)
 
-        v3 = Variable(self.root, name="abc")
-        v4 = StringVar(self.root, name="abc")
-        self.assertNotEqual(v3, v4)
+        v3 = StringVar(self.root, name="abc")
+        self.assertNotEqual(v1, v3)
+
+        V = type('Variable', (), {})
+        self.assertNotEqual(v1, V())
+
+        self.assertNotEqual(v1, object())
+        self.assertEqual(v1, ALWAYS_EQ)
 
     def test_invalid_name(self):
         with self.assertRaises(TypeError):
diff --git a/Lib/traceback.py b/Lib/traceback.py
index ab35da9..7a4c8e1 100644
--- a/Lib/traceback.py
+++ b/Lib/traceback.py
@@ -538,7 +538,9 @@ class TracebackException:
             self.__cause__._load_lines()
 
     def __eq__(self, other):
-        return self.__dict__ == other.__dict__
+        if isinstance(other, TracebackException):
+            return self.__dict__ == other.__dict__
+        return NotImplemented
 
     def __str__(self):
         return self._str
diff --git a/Lib/tracemalloc.py b/Lib/tracemalloc.py
index 2c1ac3b..80b521c 100644
--- a/Lib/tracemalloc.py
+++ b/Lib/tracemalloc.py
@@ -43,6 +43,8 @@ class Statistic:
         return hash((self.traceback, self.size, self.count))
 
     def __eq__(self, other):
+        if not isinstance(other, Statistic):
+            return NotImplemented
         return (self.traceback == other.traceback
                 and self.size == other.size
                 and self.count == other.count)
@@ -84,6 +86,8 @@ class StatisticDiff:
                      self.count, self.count_diff))
 
     def __eq__(self, other):
+        if not isinstance(other, StatisticDiff):
+            return NotImplemented
         return (self.traceback == other.traceback
                 and self.size == other.size
                 and self.size_diff == other.size_diff
@@ -153,9 +157,13 @@ class Frame:
         return self._frame[1]
 
     def __eq__(self, other):
+        if not isinstance(other, Frame):
+            return NotImplemented
         return (self._frame == other._frame)
 
     def __lt__(self, other):
+        if not isinstance(other, Frame):
+            return NotImplemented
         return (self._frame < other._frame)
 
     def __hash__(self):
@@ -200,9 +208,13 @@ class Traceback(Sequence):
         return hash(self._frames)
 
     def __eq__(self, other):
+        if not isinstance(other, Traceback):
+            return NotImplemented
         return (self._frames == other._frames)
 
     def __lt__(self, other):
+        if not isinstance(other, Traceback):
+            return NotImplemented
         return (self._frames < other._frames)
 
     def __str__(self):
@@ -271,6 +283,8 @@ class Trace:
         return Traceback(self._trace[2])
 
     def __eq__(self, other):
+        if not isinstance(other, Trace):
+            return NotImplemented
         return (self._trace == other._trace)
 
     def __hash__(self):
@@ -303,6 +317,8 @@ class _Traces(Sequence):
         return trace._trace in self._traces
 
     def __eq__(self, other):
+        if not isinstance(other, _Traces):
+            return NotImplemented
         return (self._traces == other._traces)
 
     def __repr__(self):
diff --git a/Lib/unittest/mock.py b/Lib/unittest/mock.py
index b3dc640..298b41e 100644
--- a/Lib/unittest/mock.py
+++ b/Lib/unittest/mock.py
@@ -2358,12 +2358,10 @@ class _Call(tuple):
 
 
     def __eq__(self, other):
-        if other is ANY:
-            return True
         try:
             len_other = len(other)
         except TypeError:
-            return False
+            return NotImplemented
 
         self_name = ''
         if len(self) == 2:
diff --git a/Lib/unittest/test/testmock/testmock.py b/Lib/unittest/test/testmock/testmock.py
index 18efd31..69b34e9 100644
--- a/Lib/unittest/test/testmock/testmock.py
+++ b/Lib/unittest/test/testmock/testmock.py
@@ -3,6 +3,7 @@ import re
 import sys
 import tempfile
 
+from test.support import ALWAYS_EQ
 import unittest
 from unittest.test.testmock.support import is_instance
 from unittest import mock
@@ -322,6 +323,8 @@ class MockTest(unittest.TestCase):
         self.assertFalse(mm != mock.ANY)
         self.assertTrue(mock.ANY == mm)
         self.assertFalse(mock.ANY != mm)
+        self.assertTrue(mm == ALWAYS_EQ)
+        self.assertFalse(mm != ALWAYS_EQ)
 
         call1 = mock.call(mock.MagicMock())
         call2 = mock.call(mock.ANY)
@@ -330,6 +333,11 @@ class MockTest(unittest.TestCase):
         self.assertTrue(call2 == call1)
         self.assertFalse(call2 != call1)
 
+        self.assertTrue(call1 == ALWAYS_EQ)
+        self.assertFalse(call1 != ALWAYS_EQ)
+        self.assertFalse(call1 == 1)
+        self.assertTrue(call1 != 1)
+
 
     def test_assert_called_with(self):
         mock = Mock()
diff --git a/Lib/weakref.py b/Lib/weakref.py
index fa7559b..560deee 100644
--- a/Lib/weakref.py
+++ b/Lib/weakref.py
@@ -75,14 +75,14 @@ class WeakMethod(ref):
             if not self._alive or not other._alive:
                 return self is other
             return ref.__eq__(self, other) and self._func_ref == other._func_ref
-        return False
+        return NotImplemented
 
     def __ne__(self, other):
         if isinstance(other, WeakMethod):
             if not self._alive or not other._alive:
                 return self is not other
             return ref.__ne__(self, other) or self._func_ref != other._func_ref
-        return True
+        return NotImplemented
 
     __hash__ = ref.__hash__
 
diff --git a/Lib/xmlrpc/client.py b/Lib/xmlrpc/client.py
index b987574..246ef27 100644
--- a/Lib/xmlrpc/client.py
+++ b/Lib/xmlrpc/client.py
@@ -313,31 +313,38 @@ class DateTime:
             s = self.timetuple()
             o = other.timetuple()
         else:
-            otype = (hasattr(other, "__class__")
-                     and other.__class__.__name__
-                     or type(other))
-            raise TypeError("Can't compare %s and %s" %
-                            (self.__class__.__name__, otype))
+            s = self
+            o = NotImplemented
         return s, o
 
     def __lt__(self, other):
         s, o = self.make_comparable(other)
+        if o is NotImplemented:
+            return NotImplemented
         return s < o
 
     def __le__(self, other):
         s, o = self.make_comparable(other)
+        if o is NotImplemented:
+            return NotImplemented
         return s <= o
 
     def __gt__(self, other):
         s, o = self.make_comparable(other)
+        if o is NotImplemented:
+            return NotImplemented
         return s > o
 
     def __ge__(self, other):
         s, o = self.make_comparable(other)
+        if o is NotImplemented:
+            return NotImplemented
         return s >= o
 
     def __eq__(self, other):
         s, o = self.make_comparable(other)
+        if o is NotImplemented:
+            return NotImplemented
         return s == o
 
     def timetuple(self):