python（27）- 面向对象练习Ⅰ

一：定义如下类，并最大程度地重用代码（继承，派生：子类重用父类方法，组合）
老师类
学生类
分数类
课程类
生日类

class People:
    def __init__(self,name,age,birth):
        self.name = name
        self.age = age
        self.birth=birth
 
class Teacher(People):            #继承People
    def __init__(self,name,age,birth,course):
        People.__init__(self,name,age,birth)        #子类重用父类方法
        self.course=course           #派生
 
class Student(People):            #继承People
    def __init__(self,name,age,birth,course,score):
        People.__init__(self,name,age,birth)        #子类重用父类方法
        self.course=course        #派生
        self.score=score            #派生
 
class Course:
    def __init__(self,name,price,period):
        self.name=name
        self.price=price
        self.period=period
 
class Score:
    def __init__(self,level):
        self.level=level
 
class Birth:
    def __init__(self,year,mouth,day):
        self.year=year
        self.mouth=mouth
        self.day=day
 
#类Teacher“调用”了类Birth的方法，达到了组合的效果
#同样类Student“调用”了类Birth、类Course、类Score的方法，使用了组合的概念
t1=Teacher("egon",68,Birth(1949,10,1),Course("python",15800,"6m"))
s1=Student("xuyaping",18,Birth(1949,10,1),Course("python",15800,"6m"),Score("A"))
print(s1.birth.year,s1.birth.mouth,s1.birth.day)
print(t1.course.name,t1.course.price,t1.course.period)
print(s1.score.level)

二：实现如图的继承关系，然后验证经典类与新式类在查找一个属性时的搜索顺序

#python3中新式类
class B:
    def test(self):
        print("from B")
    pass
 
class C:
    def test(self):
        print("from C")
    pass
 
class D(B,C):
    def test(self):
        print("from D")
    pass
 
class E(B,C):
    def test(self):
        print("from E")
    pass
 
class F(D,E):
    def test(self):
        print("from F")
    pass
 
f=F()
f.test()
print(F.__mro__)
--->(<class '__main__.F'>, <class '__main__.D'>, <class '__main__.E'>, <class '__main__.B'>, <class '__main__.C'>, <class 'object'>)

#python2中
#coding:utf8
class B:
    def test(self):
        print("from B")
    pass
 
class C:
    def test(self):
        print("from C")
    pass
 
class D(B,C):
    def test(self):
        print("from D")
    pass
 
class E(B,C):
    def test(self):
        print("from E")
    pass
 
class F(D,E):
    def test(self):
        print("from F")
    pass
 
f=F()
f.test()
 
#F--->D--->B--->C--->E

三：基于多态的概念来实现linux中一切皆文件的概念:文本文件，进程，磁盘都是文件，然后验证多态性

多态性：一种调用方式，不同的执行效果（多态性）
class All_file:
    def write(self):
        pass
    def read(self):
        pass
class Txt(All_file):
    def write(self):
        print("文本数据的写入")
    def read(self):
        print("文本数据的读取")
class Process(All_file):
    def write(self):
        print("进程数据的写入")
    def read(self):
        print("进程数据的读取")
class Sata(All_file):
    def write(self):
        print("磁盘数据的写入")
    def read(self):
        print("磁盘数据的读取")
 
t=Txt()
p=Process()
s=Sata()
def func(obj):
    obj.write()
    obj.read()
 
func(t)
--->文本数据的写入
    文本数据的读取
 
func(p)
--->进程数据的写入
    进程数据的读取
 
func(s)
--->磁盘数据的写入
    磁盘数据的读取