# File: parser-example-1.py import parser import symbol, token def dump_and_modify(node): name = symbol.sym_name.get(node[0]) if name is None: name = token.tok_name.get(node[0]) print name, for i in range(1, len(node)): item = node[i] if type(item) is type([]): dump_and_modify(item) else: print repr(item) if name == "NUMBER": # increment all numbers! node[i] = repr(int(item)+1) ast = parser.expr("1 + 3") list = ast.tolist() dump_and_modify(list) ast = parser.sequence2ast(list) print eval(parser.compileast(ast))