Hello! Can someone explain why this is not working? <dtml-var expr="[_.filter(lambda x: x not in [1,2,3,4,5], [2,3,4,5,2,1,2,3,5,6,7,8,9,0,8])]"> I get the following error: """ Zope has encountered an error while publishing this resource. Error Type: AttributeError Error Value: filter """ the same error occurs if I try something like <dtml-let arg="[_.filter(lambda x: x not in [1,2,3,4,5], [2,3,4,5,2,1,2,3,5,6,7,8,9,0,8])]"> dtml-var arg> </dtml-let> Any help appreciated. /dario