def isetdiff_flags ( list1 , list2 ) : set2 = set ( list2 ) return ( item not in set2 for item in list1 )
to compare set data in python
move to util_iter
def isetdiff_flags(list1, list2):
    """
    move to util_iter
    """
    set2 = set(list2)
    return (item not in set2 for item in list1)