组合

1、定义一个人的类

class Person:
    def __init__(self,id_num,name,Hand,Foot,Trunk,Head):
        self.id_num=id_num
        self.name=name
        self.hand=Hand
        self.foot=Foot
        self.trunk=Trunk
        self.head=Head

2、可以定义一些属于人的这些部件的小类，在大类Person里面实例化这些小类

class Hand:
    pass
class Foot:
    pass
class Trunk:
    pass
class Head:
    pass
class Person:
    def __init__(self,id_num,name):
        self.id_num=id_num
        self.name=name
        self.hand=Hand()
        self.foot=Foot()
        self.trunk=Trunk()
        self.head=Head()
p1=Person("123","beiye")
print(p1.__dict__)

3、定义一个学校和课程的类

class School:
    def __init__(self,name,addr):
        self.name=name
        self.addr=addr
    def zhao_sheng(self):
        print("%s 正在招生" %self.name)
class Course:
    def __init__(self,name,price,period,school):
        self.name=name
        self.price=price
        self.period=period
        self.school=school
s1=School("清华","北京")#生产3个学校的实例
s2=School("清华","南京")
s3=School("清华","东京")

# c1=Course("linux","10","1h","清华")
c1=Course("linux","10","1h",s1)#把s1传给course的school这个参数位置
print(c1.__dict__)

C:python35python3.exe D:/pyproject/day25/组合.py

{'school': <__main__.School object at 0x0000000000B54668>, 'name': 'linux', 'price': '10', 'period': '1h'}

4、现在c1的属性字典里面有school这个对象了，如何通过c1这个实例，查出来school的地址呢

class School:
    def __init__(self,name,addr):
        self.name=name
        self.addr=addr
    def zhao_sheng(self):
        print("%s 正在招生" %self.name)
class Course:
    def __init__(self,name,price,period,school):
        self.name=name
        self.price=price
        self.period=period
        self.school=school
s1=School("清华","北京")
s2=School("清华","南京")
s3=School("清华","东京")

# c1=Course("linux","10","1h","清华")
c1=Course("linux","10","1h",s1)
print(c1.__dict__)#查看c1这个实例的属性字典，里面的school就是s1
print(c1.school)#c1.school等价于s1，那如何取学校的名字呢
print(s1)

C:python35python3.exe D:/pyproject/day25/组合.py

{'name': 'linux', 'price': '10', 'period': '1h', 'school': <__main__.School object at 0x0000000000D54668>}

<__main__.School object at 0x0000000000D54668>

<__main__.School object at 0x0000000000D54668>

 

class School:
    def __init__(self,name,addr):
        self.name=name
        self.addr=addr
    def zhao_sheng(self):
        print("%s 正在招生" %self.name)
class Course:
    def __init__(self,name,price,period,school):
        self.name=name
        self.price=price
        self.period=period
        self.school=school
s1=School("清华","北京")
s2=School("清华","南京")
s3=School("清华","东京")

# c1=Course("linux","10","1h","清华")
c1=Course("linux","10","1h",s1)
print(c1.__dict__)#查看c1这个实例的属性字典，里面的school就是s1
print(c1.school.name)#这样就通过c1取出来了学校的名字，这就是一个组合

C:python35python3.exe D:/pyproject/day25/组合.py

{'price': '10', 'name': 'linux', 'period': '1h', 'school': <__main__.School object at 0x0000000000D74668>}

清华

5、选课系统，如何让用户选择

class School:
    def __init__(self,name,addr):
        self.name=name
        self.addr=addr
    def zhao_sheng(self):
        print("%s 正在招生" %self.name)
class Course:
    def __init__(self,name,price,period,school):
        self.name=name
        self.price=price
        self.period=period
        self.school=school
s1=School("清华","北京")
s2=School("清华","南京")
s3=School("清华","东京")

msg='''
1 清华 北京校区
2 清华 南京校区
3 清华 东京校区
'''
while True:
    print(msg)#调用提示信息
    menu={
        "1":s1,
        "2":s2,
        "3":s3
    }
    choice=input("选择学校>>>>>")#得到用户的输入之后，就调用字典
    school_obj=menu[choice]#得到用户选择的校区

    name=input("课程名>>>>")#
    price = input("价格>>>>")
    period = input("周期>>>>")

    new_course=Course(name,price,period,school_obj)#生成一个新的课程类
    print("课程【%s】属于[%s]学校【%s】校区" %(new_course.name,new_course.school.name,new_course.school.addr))
    #调用新课程和学校名，和校区名字

选择学校>>>>>2

课程名>>>>python

价格>>>>100

周期>>>>1month

课程【python】属于[清华]学校【南京】校区