fix more tests for Python 2.6

test/operands.py

@@ -1,6 +1,9 @@
 #!/usr/bin/env python
 
 # Tests accessing of instruction operands.
+import sys
+import logging
+import unittest
 
 from llvm.core import *
 try:
@@ -8,8 +11,6 @@ try:
 except ImportError:
     from io import StringIO
 
-import logging, unittest
-
 m = None
 
 #===----------------------------------------------------------------------===
@@ -32,6 +33,14 @@ entry:
 """
 
 class TestOperands(unittest.TestCase):
+
+    if sys.version_info[:2] < (2, 7):
+        def assertIs(self, expr1, expr2, msg=None):
+            if expr1 is not expr2:
+                standardMsg = '%s is not %s' % (safe_repr(expr1),
+                                                safe_repr(expr2))
+                self.fail(self._formatMessage(msg, standardMsg))
+
     def test_operands(self):
         m = Module.from_assembly(StringIO(test_module))
         logging.debug("-"*60)