#NEWLINE# def set_subtract( self , a , b ) : #NEWLINE# #INDENT# "Returns the elements of a that are not in b.\n\n        >>> t = Generator('', [], [], [])\n        >>> t.set_subtract([], [])\n        []\n        >>> t.set_subtract([1, 2], [1, 2])\n        []\n        >>> t.set_subtract([1, 2, 3], [2])\n        [1, 3]\n        >>> t.set_subtract([1], [2, 3, 4])\n        [1]\n        " #NEWLINE# result = [ ] #NEWLINE# for x in a : #NEWLINE# #INDENT# if ( x not in b ) : #NEWLINE# #INDENT# result . append ( x ) #NEWLINE# #UNINDENT# #UNINDENT# return result