定义一个Person类有name, age, sex的公有成员变量，以及一个showinfor（）的方法对该类的三个属性进行打印。再定义一个Teacher类，该类继承Person类，并且额外新增一个department的公有成员变量，也对Teacher类定义一个showinfor（）的方法对该类的四个属性进行打印。再定义一个Student类，该类继承Person类，并且额外新增一个marks的公有成员变量，也对Student类定义一个showinfor（）的方法对该类的四个属性进行打印。 （2）完成上述题目的三个类的定义后，分别对不同的三个类创建一个实例对象并封装再一个列表里面，对该列表的三个不同对象按照年龄从从大到小进行排序，并打印排序后的结果。(建议使用lambda表达式对对象列表进行排序)。

好的，我明白了。以下是对你的问题的回答：

class Person:
    def __init__(self, name, age, sex):
        self.name = name
        self.age = age
        self.sex = sex
    
    def showinfor(self):
        print(f"Name: {self.name}, Age: {self.age}, Sex: {self.sex}")

class Teacher(Person):
    def __init__(self, name, age, sex, department):
        super().__init__(name, age, sex)
        self.department = department
    
    def showinfor(self):
        print(f"Name: {self.name}, Age: {self.age}, Sex: {self.sex}, Department: {self.department}")

class Student(Person):
    def __init__(self, name, age, sex, marks):
        super().__init__(name, age, sex)
        self.marks = marks
    
    def showinfor(self):
        print(f"Name: {self.name}, Age: {self.age}, Sex: {self.sex}, Marks: {self.marks}")

teacher1 = Teacher('Lucy', 32, 'Female', 'Math')
teacher2 = Teacher('Smith', 45, 'Male', 'Physics')
student1 = Student('John', 18, 'Male', 80)
student2 = Student('Alice', 20, 'Female', 92)

people_list = [teacher1, teacher2, student1, student2]
people_sorted = sorted(people_list, key=lambda p: p.age, reverse=True)

for p in people_sorted:
    p.showinfor()

输出结果：

Name: Smith, Age: 45, Sex: Male, Department: Physics
Name: Lucy, Age: 32, Sex: Female, Department: Math
Name: Alice, Age: 20, Sex: Female, Marks: 92
Name: John, Age: 18, Sex: Male, Marks: 80