--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/ztfy/utils/list.py	Fri Aug 17 16:13:21 2012 +0200
@@ -0,0 +1,40 @@
+### -*- coding: utf-8 -*- ####################################################
+##############################################################################
+#
+# Copyright (c) 2012 Thierry Florac <tflorac AT ulthar.net>
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE.
+#
+##############################################################################
+
+
+# import standard packages
+
+# import Zope3 interfaces
+
+# import local interfaces
+
+# import Zope3 packages
+
+# import local packages
+
+
+def unique(seq, idfun=None):
+    """Get list unique values, preserving order"""
+    if idfun is None:
+        def idfun(x): return x
+    seen = {}
+    result = []
+    for item in seq:
+        marker = idfun(item)
+        if marker in seen:
+            continue
+        seen[marker] = 1
+        result.append(item)
+    return result