Index: hla/omt/array.py
===================================================================
RCS file: /sources/certi/applications/PyHLA/hla/omt/array.py,v
retrieving revision 1.4
diff -u -r1.4 array.py
--- hla/omt/array.py	23 Jun 2011 18:45:37 -0000	1.4
+++ hla/omt/array.py	19 Sep 2011 11:25:31 -0000
@@ -37,12 +37,12 @@
         return self.elementType.octetBoundary
 
     def pack(self, value):
-        buffer = ""
+        buffer = bytes()
         if(len(value) != self.cardinality):
             raise TypeError("expecting %i elements" % (self.cardinality))
 
         for element in value:
-            buffer += padding(len(buffer), self.elementType.octetBoundary)*'\0'
+            buffer += padding(len(buffer), self.elementType.octetBoundary) * bytes("\0", encoding='utf-8')
             buffer += self.elementType.pack(element)
 
         return buffer
@@ -74,7 +74,7 @@
             raise TypeError("expecting %i elements" % (self.cardinality))
 
         for element in value:
-            buffer += padding(len(buffer), self.elementType.octetBoundary)*'\0'
+            buffer += padding(len(buffer), self.elementType.octetBoundary)* bytes("\0", encoding='utf-8')
             buffer += self.elementType.pack(element)
 
         return buffer
Index: hla/omt/basic.py
===================================================================
RCS file: /sources/certi/applications/PyHLA/hla/omt/basic.py,v
retrieving revision 1.1
diff -u -r1.1 basic.py
--- hla/omt/basic.py	25 Sep 2008 17:17:44 -0000	1.1
+++ hla/omt/basic.py	19 Sep 2011 11:25:31 -0000
@@ -16,5 +16,12 @@
 def padding(size, boundary):
     return boundary - ((size-1)%boundary + 1)
 
+# Test Python version and define the 'bytes' operator accordingly
+from sys import version_info
+
+if version_info < (3,0):
+    def bytes(string='', encoding="utf-8"):
+        return string
+
 # $Id: basic.py,v 1.1 2008/09/25 17:17:44 gotthardp Exp $
 
Index: hla/omt/record.py
===================================================================
RCS file: /sources/certi/applications/PyHLA/hla/omt/record.py,v
retrieving revision 1.4
diff -u -r1.4 record.py
--- hla/omt/record.py	23 Jun 2011 18:45:37 -0000	1.4
+++ hla/omt/record.py	19 Sep 2011 11:25:31 -0000
@@ -44,9 +44,9 @@
         return self._octetBoundary
 
     def pack(self, value):
-        buffer = ""
+        buffer = bytes()
         for fieldName, fieldType in self.fields:
-            buffer += padding(len(buffer), fieldType.octetBoundary)*'\0'
+            buffer += padding(len(buffer), fieldType.octetBoundary) * bytes("\0", encoding='utf-8')
             buffer += fieldType.pack(value[fieldName])
         return buffer
 
@@ -102,10 +102,10 @@
         buffer = self.discriminantType.pack(value[self.discriminantName])
         fieldName, fieldType = self.getAlternative(value[self.discriminantName])
         if(fieldName != None):
-            buffer += padding(len(buffer), fieldType.octetBoundary)*'\0'
+            buffer += padding(len(buffer), fieldType.octetBoundary) *  bytes("\0", encoding='utf-8')
             buffer += fieldType.pack(value[fieldName])
         else:
-            buffer += padding(len(buffer), self.octetBoundary)*'\0'
+            buffer += padding(len(buffer), self.octetBoundary) *  bytes("\0", encoding='utf-8')
         return buffer
 
     def unpack(self, buffer, offset = 0):