python3 面向对象类继承组合派生接口子类重用父类方法

Posted 2020-09-26

对象是特征（变量）与技能（函数）的结合体
而类是一系列对象共同的特征与技能的集合体

class teacher:

    lesson = "python"

    def __init__(self,name,color,age):  # 只干初始化的活
        self.name = name
        if not isinstance(name,str):
            raise TypeError
        self.color = color
        self.age = age

    def jineng(self):
        print(‘新技能‘)

t1 = teacher(‘as‘,‘pink‘,13)   # t1可以成为teacher类的一个实例，或对象

class teacher:
    # 特征
    school = ‘oldboy‘
    lesson_default = ‘python‘

    # 技能
    def __init__(self,name,age,sex,lesson2):
        self.name = name
        self.age = age
        self.sex = sex
        self.lesson2 = lesson2
    def speak(self):
        print(‘讲课‘)
    def eat(self):
        print(‘吃饭‘)

t1 = teacher(‘alex‘,‘23‘,‘男‘,‘运维‘)
t2 = teacher(‘egon‘,‘24‘,‘男‘,‘运维‘)

类的用法一：实例化产生对象
类的用法二：属性引用
print(teacher.__dict__)


# 对象的属性
# 类的属性

# 属性，就是一个字典
# 对象查看一个属性，先从对象属性找，如果没有，就从类找

继承：
继承是用来创建新的类的一种方式，好处是可以减少重复代码
继承是类与类之间的关系，是一种什么是什么的关系

class People:
    def __init__(self,name,age,sex):
        self.name = name
        self.age = age
        self.sex = sex
    def walk(self):
        print(‘%s is walking‘ %self.name)
    def foo(self):
        print(‘from father %s‘ %self.name)

class Teacher(People):
    school = ‘oldboy‘
    def __init__(self,name,age,sex,level,salary):
        People.__init__(self,name,age,sex)
        self.level = level
        self.salary = salary
    def bar(self):
        People.foo(self)
        print(‘from teacher‘)

class Student(People):
    pass

t = Teacher(‘egon‘,13,‘male‘,10,3000)
# print(t.name,t.age)
print(t.__dict__)
t.walk()
t.bar()

组合
组合是一种什么有什么的关系

class People:
    def __init__(self, name, age, year, mon, day):
        self.name = name
        self.age = age
        self.birth = Date(year, mon, day) 　　# 组合

    def walk(self):
        print(‘%s is walking‘ % self.name)


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(People):
    def __init__(self, name, age, year, mon, day, level, salary):
        People.__init__(self, name, age, year, mon, day)
        self.level = level
        self.salary = salary

    def teach(self):
        print(‘%s is teaching‘ % self.name)


class Student(People):
    def __init__(self, name, age, year, mon, day, group):
        People.__init__(self, name, age, year, mon, day)
        self.group = group

    def study(self):
        print(‘%s is studying‘ % self.name)

t = Teacher(‘egon‘, 12, 1991, 12, 12, 10, 1000)
t.teach()
t.walk()
print(t.level)
print(t.birth.tell_birth())

接口
1.子类必须要有父类的方法
2.子类实现的方法必须跟父类的方法的名字一样

class File:#定义接口Interface类来模仿接口的概念，python中压根就没有interface关键字来定义一个接口。
    def read(self): #定接口函数read
        pass

    def write(self): #定义接口函数write
        pass

class Txt(File): #文本，具体实现read和write
    def du(self):
        print(‘文本数据的读取方法‘)

    def xie(self):
        print(‘文本数据的读取方法‘)

class Sata(File): #磁盘，具体实现read和write
    def read(self):
        print(‘硬盘数据的读取方法‘)

    def write(self):
        print(‘硬盘数据的读取方法‘)

class Process(File):
    def read(self):
        print(‘进程数据的读取方法‘)

    def write(self):
        print(‘进程数据的读取方法‘)

txt=Txt()
disk=Sata()
process=Process()

txt.du()
# disk.read()
# process.read()

子类实现的方法必须跟父类的方法的名字一样

import abc

class File(metaclass=abc.ABCMeta):
    @abc.abstractmethod
    def read(self):
        pass

    @abc.abstractmethod
    def write(self):
        pass

class Txt(File):  # 文本，具体实现read和write
    def read(self):
        pass

    def write(self):
        pass

t = Txt()