class  SchoolMember(object):
    '''学习成员基类'''
    member=0

    def __init__(self,name,age,sex):
        self.name=name
        self.age=age
        self.sex=sex
        self.enroll()

    def enroll(self):
        '注册'
        print('just enrolled a new school member {}.'.format(self.name))
        SchoolMember.member+=1

    def tell(self):
        print('---{}---'.format(self.name))
        for k,v in self.__dict__.items():
            print(k,v)

        print('----end----')

    def delete(self):
        print('开除了{}'.format(self.name))
        SchoolMember.member-=1

class Teacher(SchoolMember):
    '教师'
    def __init__(self,name,age,sex,salary,course):
        SchoolMember.__init__(self,name,age,sex)
        self.salary=salary
        self.course=course


    def teaching(self):
        print('Teacher {} is teaching {}'.format(self.name,self.course))


class Student(SchoolMember):
    '学生'
    def __init__(self,name,age,sex,course,tuition):
        SchoolMember.__init__(self,name,age,sex)
        self.course=course
        self.tuition=tuition
        self.amount=0

    def pay_tuition(self,amount):
        print('student {} has just paied {}'.format(self.name,self.amount))
        self.amount+=amount

t1=Teacher('Wusir',28,'M','3000','python')
t1.tell()
s1 = Student('haitao', 38, 'M', 'python', 30000)
s1.tell()
s2 = Student('lichuang', 12, 'M', 'python', 11000)
print(SchoolMember.member)
s2.delete()

print(SchoolMember.member)