Issue 2235: Py3k warnings are now emitted for classes that will no longer inherit a__hash__ implementation from a parent class in Python 3.x. The standard library and test suite have been updated to not emit these warnings.

nick.coghlan · nick.coghlan · commit acc618cacf42 · 2008-08-11T15:45:58.000Z
git-svn-id: http://svn.python.org/projects/python/trunk@65642 6015fed2-1504-0410-9fe1-9d1591cc4771
diff --git a/Lib/UserList.py b/Lib/UserList.py
@@ -25,6 +25,7 @@ def __cast(self, other):
         else: return other
     def __cmp__(self, other):
         return cmp(self.data, self.__cast(other))
+    __hash__ = None # Mutable sequence, so not hashable
     def __contains__(self, item): return item in self.data
     def __len__(self): return len(self.data)
     def __getitem__(self, i): return self.data[i]
diff --git a/Lib/_abcoll.py b/Lib/_abcoll.py
@@ -207,6 +207,9 @@ def __xor__(self, other):
             other = self._from_iterable(other)
         return (self - other) | (other - self)
 
+    # Sets are not hashable by default, but subclasses can change this
+    __hash__ = None
+
     def _hash(self):
         """Compute the hash value of a set.
 
@@ -350,6 +353,9 @@ def items(self):
     def values(self):
         return [self[key] for key in self]
 
+    # Mappings are not hashable by default, but subclasses can change this
+    __hash__ = None
+
     def __eq__(self, other):
         return isinstance(other, Mapping) and \
                dict(self.items()) == dict(other.items())
diff --git a/Lib/ctypes/test/test_simplesubclasses.py b/Lib/ctypes/test/test_simplesubclasses.py
@@ -6,6 +6,8 @@ def __cmp__(self, other):
         if type(other) != MyInt:
             return -1
         return cmp(self.value, other.value)
+    def __hash__(self): # Silence Py3k warning
+        return hash(self.value)
 
 class Test(unittest.TestCase):
 
diff --git a/Lib/numbers.py b/Lib/numbers.py
@@ -18,6 +18,9 @@ class Number(object):
     """
     __metaclass__ = ABCMeta
 
+    # Concrete numeric types must provide their own hash implementation
+    __hash__ = None
+
 
 ## Notes on Decimal
 ## ----------------
diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py
@@ -1064,6 +1064,7 @@ def test_range(self):
         class badzero(int):
             def __cmp__(self, other):
                 raise RuntimeError
+            __hash__ = None # Invalid cmp makes this unhashable
         self.assertRaises(RuntimeError, range, a, a + 1, badzero(1))
 
         # Reject floats when it would require PyLongs to represent.
diff --git a/Lib/test/test_coercion.py b/Lib/test/test_coercion.py
@@ -309,6 +309,7 @@ class WackyComparer(object):
             def __cmp__(slf, other):
                 self.assert_(other == 42, 'expected evil_coercer, got %r' % other)
                 return 0
+            __hash__ = None # Invalid cmp makes this unhashable
         self.assertEquals(cmp(WackyComparer(), evil_coercer), 0)
         # ...and classic classes too, since that code path is a little different
         class ClassicWackyComparer:
diff --git a/Lib/test/test_collections.py b/Lib/test/test_collections.py
@@ -172,6 +172,7 @@ def test_Hashable(self):
         class H(Hashable):
             def __hash__(self):
                 return super(H, self).__hash__()
+            __eq__ = Hashable.__eq__ # Silence Py3k warning
         self.assertEqual(hash(H()), 0)
         self.failIf(issubclass(int, H))
 
diff --git a/Lib/test/test_copy.py b/Lib/test/test_copy.py
@@ -435,6 +435,7 @@ def __reduce__(self):
                 return (C, (), self.__dict__)
             def __cmp__(self, other):
                 return cmp(self.__dict__, other.__dict__)
+            __hash__ = None # Silence Py3k warning
         x = C()
         x.foo = [42]
         y = copy.copy(x)
@@ -451,6 +452,7 @@ def __setstate__(self, state):
                 self.__dict__.update(state)
             def __cmp__(self, other):
                 return cmp(self.__dict__, other.__dict__)
+            __hash__ = None # Silence Py3k warning
         x = C()
         x.foo = [42]
         y = copy.copy(x)
@@ -477,6 +479,7 @@ def __reduce__(self):
             def __cmp__(self, other):
                 return (cmp(list(self), list(other)) or
                         cmp(self.__dict__, other.__dict__))
+            __hash__ = None # Silence Py3k warning
         x = C([[1, 2], 3])
         y = copy.copy(x)
         self.assertEqual(x, y)
@@ -494,6 +497,7 @@ def __reduce__(self):
             def __cmp__(self, other):
                 return (cmp(dict(self), list(dict)) or
                         cmp(self.__dict__, other.__dict__))
+            __hash__ = None # Silence Py3k warning
         x = C([("foo", [1, 2]), ("bar", 3)])
         y = copy.copy(x)
         self.assertEqual(x, y)
diff --git a/Lib/test/test_datetime.py b/Lib/test/test_datetime.py
@@ -986,6 +986,7 @@ def __cmp__(self, other):
                 # compare-by-address (which never says "equal" for distinct
                 # objects).
                 return 0
+            __hash__ = None # Silence Py3k warning
 
         # This still errors, because date and datetime comparison raise
         # TypeError instead of NotImplemented when they don't know what to
diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py
@@ -1121,6 +1121,7 @@ class F(object):
         class G(object):
             def __cmp__(self, other):
                 return 0
+            __hash__ = None # Silence Py3k warning
         g = G()
         orig_objects = len(gc.get_objects())
         for i in xrange(10):
@@ -2727,6 +2728,7 @@ def __cmp__(self, other):
                     if isinstance(other, int) or isinstance(other, long):
                         return cmp(self.value, other)
                     return NotImplemented
+                __hash__ = None # Silence Py3k warning
 
             c1 = C(1)
             c2 = C(2)
@@ -2755,6 +2757,7 @@ def __eq__(self, other):
                     return abs(self - other) <= 1e-6
                 except:
                     return NotImplemented
+            __hash__ = None # Silence Py3k warning
         zz = ZZ(1.0000003)
         self.assertEqual(zz, 1+0j)
         self.assertEqual(1+0j, zz)
@@ -2767,6 +2770,7 @@ def __init__(self, value):
                     self.value = int(value)
                 def __cmp__(self_, other):
                     self.fail("shouldn't call __cmp__")
+                __hash__ = None # Silence Py3k warning
                 def __eq__(self, other):
                     if isinstance(other, C):
                         return self.value == other.value
@@ -3262,6 +3266,7 @@ def __rpow__(self, other, mod=None):
         class S(str):
             def __eq__(self, other):
                 return self.lower() == other.lower()
+            __hash__ = None # Silence Py3k warning
 
     def test_subclass_propagation(self):
         # Testing propagation of slot functions to subclasses...
diff --git a/Lib/test/test_hash.py b/Lib/test/test_hash.py
@@ -52,6 +52,9 @@ def __hash__(self):
 class OnlyEquality(object):
     def __eq__(self, other):
         return self is other
+    # Trick to suppress Py3k warning in 2.x
+    __hash__ = None
+del OnlyEquality.__hash__
 
 class OnlyInequality(object):
     def __ne__(self, other):
@@ -60,6 +63,9 @@ def __ne__(self, other):
 class OnlyCmp(object):
     def __cmp__(self, other):
         return cmp(id(self), id(other))
+    # Trick to suppress Py3k warning in 2.x
+    __hash__ = None
+del OnlyCmp.__hash__
 
 class InheritedHashWithEquality(FixedHash, OnlyEquality): pass
 class InheritedHashWithInequality(FixedHash, OnlyInequality): pass
@@ -71,18 +77,15 @@ class NoHash(object):
 class HashInheritanceTestCase(unittest.TestCase):
     default_expected = [object(),
                         DefaultHash(),
+                        OnlyEquality(),
+                        OnlyInequality(),
+                        OnlyCmp(),
                        ]
     fixed_expected = [FixedHash(),
                       InheritedHashWithEquality(),
                       InheritedHashWithInequality(),
                       InheritedHashWithCmp(),
                       ]
-    # TODO: Change these to expecting an exception
-    # when forward porting to Py3k
-    warning_expected = [OnlyEquality(),
-                        OnlyInequality(),
-                        OnlyCmp(),
-                       ]
     error_expected = [NoHash()]
 
     def test_default_hash(self):
@@ -93,20 +96,13 @@ def test_fixed_hash(self):
         for obj in self.fixed_expected:
             self.assertEqual(hash(obj), _FIXED_HASH_VALUE)
 
-    def test_warning_hash(self):
-        for obj in self.warning_expected:
-            # TODO: Check for the expected Py3k warning here
-            obj_hash = hash(obj)
-            self.assertEqual(obj_hash, _default_hash(obj))
-
     def test_error_hash(self):
         for obj in self.error_expected:
             self.assertRaises(TypeError, hash, obj)
 
     def test_hashable(self):
         objects = (self.default_expected +
-                   self.fixed_expected +
-                   self.warning_expected)
+                   self.fixed_expected)
         for obj in objects:
             self.assert_(isinstance(obj, Hashable), repr(obj))
 
diff --git a/Lib/test/test_operator.py b/Lib/test/test_operator.py
@@ -57,6 +57,7 @@ def test_eq(self):
         class C(object):
             def __eq__(self, other):
                 raise SyntaxError
+            __hash__ = None # Silence Py3k warning
         self.failUnlessRaises(TypeError, operator.eq)
         self.failUnlessRaises(SyntaxError, operator.eq, C(), C())
         self.failIf(operator.eq(1, 0))
diff --git a/Lib/test/test_py3kwarn.py b/Lib/test/test_py3kwarn.py
diff --git a/Lib/test/test_slice.py b/Lib/test/test_slice.py
diff --git a/Lib/test/test_sort.py b/Lib/test/test_sort.py
diff --git a/Lib/unittest.py b/Lib/unittest.py
diff --git a/Lib/xml/dom/minidom.py b/Lib/xml/dom/minidom.py
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
