Author: guido.van.rossum
Date: Wed Mar 28 00:37:34 2007
New Revision: 54588

Modified:
   python/branches/p3yk/Lib/test/test_compare.py
   python/branches/p3yk/Misc/NEWS
   python/branches/p3yk/Objects/typeobject.c
Log:
By default, != returns the opposite of ==, unless the latter returns
NotImplemented.

(Is this worth backporting to 2.6?  It seems so useful...!)


Modified: python/branches/p3yk/Lib/test/test_compare.py
==============================================================================
--- python/branches/p3yk/Lib/test/test_compare.py       (original)
+++ python/branches/p3yk/Lib/test/test_compare.py       Wed Mar 28 00:37:34 2007
@@ -39,6 +39,12 @@
                 self.assertEqual(a == b, id(a) == id(b),
                                  'a=%r, b=%r' % (a, b))
 
+    def test_ne_defaults_to_not_eq(self):
+        a = Cmp(1)
+        b = Cmp(1)
+        self.assertTrue(a == b)
+        self.assertFalse(a != b)
+
 def test_main():
     test_support.run_unittest(ComparisonTest)
 

Modified: python/branches/p3yk/Misc/NEWS
==============================================================================
--- python/branches/p3yk/Misc/NEWS      (original)
+++ python/branches/p3yk/Misc/NEWS      Wed Mar 28 00:37:34 2007
@@ -28,6 +28,9 @@
 Core and Builtins
 -----------------
 
+- By default, != returns the opposite of ==, unless the latter returns
+  NotImplemented.
+
 - Patch #1680961: sys.exitfunc has been removed and replaced with a private
   C-level API.
 

Modified: python/branches/p3yk/Objects/typeobject.c
==============================================================================
--- python/branches/p3yk/Objects/typeobject.c   (original)
+++ python/branches/p3yk/Objects/typeobject.c   Wed Mar 28 00:37:34 2007
@@ -2314,7 +2314,22 @@
                break;
 
        case Py_NE:
-               res = (self != other) ? Py_True : Py_False;
+               /* By default, != returns the opposite of ==,
+                  unless the latter returns NotImplemented. */
+               res = PyObject_RichCompare(self, other, Py_EQ);
+               if (res != NULL && res != Py_NotImplemented) {
+                       int ok = PyObject_IsTrue(res);
+                       Py_DECREF(res);
+                       if (ok < 0)
+                               res = NULL;
+                       else {
+                               if (ok)
+                                       res = Py_False;
+                               else
+                                       res = Py_True;
+                               Py_INCREF(res);
+                       }
+               }
                break;
 
        default:
_______________________________________________
Python-3000-checkins mailing list
[email protected]
http://mail.python.org/mailman/listinfo/python-3000-checkins

Reply via email to