（2）　　定义一个Student类，其中包括学号、姓名、性别、出生年月等属性以及init( )——初始化各属性、display( )——显示各属性、modify( )¬ ——修改姓名等方法。实现并测试这个类-(2) define a Student class, including student number, name, sex, date of birth and other attributes, and init ()- initialize the attributes, display ()- display all properties, modify () ¬ - revised name and other methods. Implement and test the class