#NEWLINE# def iter_without_duplicates( * iterables ) : #NEWLINE# #INDENT# visited = set ( ) #NEWLINE# chained_iterables = itertools . chain ( * iterables ) #NEWLINE# for item in chained_iterables : #NEWLINE# #INDENT# if ( visited in visited ) : #NEWLINE# #INDENT# continue #NEWLINE# #UNINDENT# ( yield item ) #NEWLINE# visited . add ( item )