--- a/src/pyams_utils/list.py	Tue May 10 16:44:27 2016 +0200
+++ b/src/pyams_utils/list.py	Thu May 12 10:41:22 2016 +0200
@@ -23,10 +23,21 @@
 def unique(seq, idfun=None):
     """Extract unique values from list, preserving order
 
+    Original list is not modified.
+
     >>> from pyams_utils.list import unique
     >>> mylist = [1, 2, 3, 2, 1]
     >>> unique(mylist)
     [1, 2, 3]
+
+    >>> mylist = [3, 2, 2, 1, 4, 2]
+    >>> unique(mylist)
+    [3, 2, 1, 4]
+
+    You can also set an 'id' function applied on each element:
+    >>> mylist = [1, 2, 3, '2', 4]
+    >>> unique(mylist, idfun=str)
+    [1, 2, 3, 4]
     """
     if idfun is None:
         def idfun(x): return x