changeset:   105336:c2cb70c97163
branch:      3.6
user:        Victor Stinner <victor.stinner@gmail.com>
date:        Tue Nov 22 15:30:38 2016 +0100
files:       Lib/test/test_re.py Modules/_sre.c
description:
Issue #28727: Optimize pattern_richcompare() for a==a

A pattern is equal to itself.


diff -r 6b43d15fd2d7 -r c2cb70c97163 Lib/test/test_re.py
--- a/Lib/test/test_re.py	Tue Nov 22 15:23:00 2016 +0100
+++ b/Lib/test/test_re.py	Tue Nov 22 15:30:38 2016 +0100
@@ -1781,6 +1781,10 @@
     def test_pattern_compare(self):
         pattern1 = re.compile('abc', re.IGNORECASE)
 
+        # equal to itself
+        self.assertEqual(pattern1, pattern1)
+        self.assertFalse(pattern1 != pattern1)
+
         # equal
         re.purge()
         pattern2 = re.compile('abc', re.IGNORECASE)
diff -r 6b43d15fd2d7 -r c2cb70c97163 Modules/_sre.c
--- a/Modules/_sre.c	Tue Nov 22 15:23:00 2016 +0100
+++ b/Modules/_sre.c	Tue Nov 22 15:30:38 2016 +0100
@@ -2683,6 +2683,12 @@
     if (Py_TYPE(lefto) != &Pattern_Type || Py_TYPE(righto) != &Pattern_Type) {
         Py_RETURN_NOTIMPLEMENTED;
     }
+
+    if (lefto == righto) {
+        /* a pattern is equal to itself */
+        return PyBool_FromLong(op == Py_EQ);
+    }
+
     left = (PatternObject *)lefto;
     right = (PatternObject *)righto;