def sub_output(self, *keys):
result = []<EOL>for key in keys:<EOL><INDENT>if self.get(key):<EOL><INDENT>result.append(key + '<STR_LIT:=>' + self.get(key).value)<EOL><DEDENT><DEDENT>return '<STR_LIT>'.join(result)<EOL>
获取一部分cookie, 并将它输出为字符串