类组合

class Date:
    def __init__(self,year,mon,day):
        self.year=year
        self.mon=mon
        self.day=day
    def tell_birth(self):
        print('出生于<%s>年 <%s>月 <%s>日'%(self.year,self.mon,self.day))


class Teacher:
    def __init__(self,name,age,sex,year,month,day):
        self.name=name
        self.age=age
        self.sex=sex
        self.birth=Date(year,month,day)
    def teaching(self):
        print('%s is teaching'%self.name)
class Student:
    def __init__(self,name,age,sex,year,mon,day):
        self.name=name
        self.age=age
        self.sex=sex
        self.birth=Date(year,mon,day)
    def studying(self):
        print('%s is studying'%self.name)

xiaobai=Student('xiaobai',22,'male','1995','3','16')
xiaobai.birth.tell_birth()

# class Hand:
#     pass
# class Foot:
#     pass
# class Trunk:
#     pass
# class Head:
#     pass
# class Person:
#     def __init__(self,id_num,name):
#         self.id_nim=id_num
#         self.name=name
#         self.hand=Hand()
#         self.foot=Foot()
#         self.trunk=Trunk()
#         self.head=Hand()
# p1=Person("111","alex")

# class School:
#      def __init__(self,name,addr):
#          self.name=name
#          self.addr=addr
#
# class Course:
#     def __init__(self,name,price,period,school):
#         self.name=name
#         self.price=price
#         self.period=period
#         self.school=school
# s1=School("北大","白金")
# c1=Course("linux",1333,"1h",s1)
#
#
# print(c1.school.name)   主要是查看c1下的学校
 



使用主要方法
class School:
    def __init__(self, name, addr):
        self.name = name
        self.addr = addr
    # def admissions(self,naem,addr):
    #     print("%s 正在招生 %s" %(self.name,addr))

class Course:
    def __init__(self, name, price, period, school):
        self.name = name
        self.price = price
        self.period = period
        self.school = school
    # def xia_ke(self,name,):
    #     print("%s 下课了 %s" %(self.name))

s1 = School("北大", "白金")
s2 = School("r大", "白金")
s3 = School("北3", "白金")
c1 = Course("linux", 1333, "1h", s1)
# s1.admissions("k","gg")

msg="""
1  北大 白金
2   r大 白金
3   北3 白金

"""
while True:
    print(msg)
    menu={
        "1":s1,
        "2":s2,
        "3":s3
    }
    choice=input("选择学校》》：")
    school_obj=menu[choice]
    name=input("课程名》》：")
    price=input("课程费用》》：")
    period=input("课程周期》》：")
    new_course=Course(name,price,period,school_obj)
    print("课程【%s】属于[%s]学校"%(new_course.name,new_course.school.name))