def Subscript(index_node):
 return Node(syms.trailer, [Leaf(token.LBRACE, u'['), index_node, Leaf(token.RBRACE, u']')])

def Subscript ( index_node ) : return Node ( syms . trailer , [ Leaf ( token . LBRACE , u'[' ) , index_node , Leaf ( token . RBRACE , u']' ) ] )
a numeric or string subscript .