python继承

时间 2019-11-24

标签 python 继承栏目 Python 繁體版

原文原文链接

#继承
#衍生的类（子类）继承父类的方法和数据成员
#语法：
# class 子类：父类
# {......}
#子类继承父类，父类派生子类。父类又叫基类，子类又叫派生类
class Vehicle:
    def __init__(self,name):
        self.name ='';
        print('交通工具被初始化  建立出来');
    def run(self):
        print('交通工具在行驶...');
    def show(self):
        print('车的名字是%s' % self.name);
class Truck(Vehicle):#子类（父类）；继承语法
    def __init__(self,name,weith):#子类的构造方法应该包含父类和子类的共同属性
        #Vehicle.name = name;  # 一、调用父类属性，在__init__()方法中使用父类.属性
        self.name = name;  # 二、调用父类属性，在__init__()方法中使用self.属性或父类
        #Vehicle.__init__(self.name);#一、调用父类方法 __init__(self,参数)
        # super(Vehicle, self).__init__(name);#二、一、调用父类方法 super(父类,self).__init__(参数)
        self.weith=weith;
        print('卡车被初始化  建立出来');
#方法重写
    def run(self):
        Vehicle.show(self);
        print('%s卡车载重%d吨 行驶中...'%(self.name,self.weith));
class Trian(Vehicle):
    def __init__(self,name,nums):
        self.nums=nums;
    def run(self):
        print('火车在轨道上行驶...');

t=Truck('东风',15);
t.run();

class cixunfu:

    def run(self):
        print('在磁悬浮轨道上行驶..')

class student:

    def goHome(self,vehicle):
        vehicle.run()
        print('学生在回家的途中...')

class tui:
    def run(self):
        print('2条腿儿在行驶...')
# c=Trian('京沪高铁',30);
# c.run();
# ok=Trian('马航730',30);
daizhong=tui();
xinpeng=student();
xinpeng.goHome(daizhong);

宠物看病函数

#宠物看病
class pet:
    def kanbing(self):
        print('给宠物看病...');
class Car(pet):
    def kanbing(self):
        print('给猫咪看病 吃药，吃小黄鱼..');
class  Dog(pet):
    def kanbing(self):
        print('给狗狗看病 输液，吃骨头..');
class bird(pet):
    def kanbing(self):
        print('给小鸟看病 拔罐，吃虫子..');
class pig(pet):
    def kanbing(self):
        print('给小猪看病 针灸，吃猪粮..');
class ShouVet:
    def JiuZhen(self,pet):
        print('兽医出诊..给宠物看病..');
        pet.kanbing();

dingdang=Car();
kala=Dog();
huangli=bird();
peiqi=pig();
syi=ShouVet();

syi.JiuZhen(dingdang);
syi.JiuZhen(kala);
syi.JiuZhen(huangli);
syi.JiuZhen(peiqi);

# isinstance()函数：判断是不是继承关系
print('kala is Dog:',isinstance(kala,Dog));

计算器工具

#计算器
class Operation:
    def __init__(self,numA,numB):
        self.numA=numA;
        self.numB=numB;

    def GetResult(self):
        print('计算2操做数的运算结果');

class OpeartionAdd(Operation):
    def __init__(self,numA,numB):
        super(OpeartionAdd, self).__init__(numA,numB);
    def GetResult(self):
        return self.numA+self.numB;

class OpeartionSub(Operation):
    def __init__(self,numA,numB):
       # super(OpeartionSub, self).__init__(numA,numB);
        super(OpeartionSub, self).__init__(munA,numB);
    def GetResult(self):
        return self.numA-self.numB;

class OpeartionMul(Operation):
    def __init__(self,numA,numB):
        super(OpeartionMul, self).__init__(numA,numB);
    def GetResult(self):
        return self.numA*self.numB;

class OpeartionDiv(Operation):
    def __init__(self,numA,numB):
        super(OpeartionDiv, self).__init__(numA,numB);
    def GetResult(self):
        return self.numA//self.numB;

if __name__=='__main__':
    numA=int(input('请输入第一个操做数：'));
    numB=int(input('请输入第二个操做数：'));
    fu=input('请输入运算符：');
    q=None;#未赋值的变量 表明一个计算器
    if fu=='+':
        q=OpeartionAdd(numA,numB);
    elif fu=='-':
        q = OpeartionSub(numA, numB);
    elif fu == '*':
        q = OpeartionMul(numA, numB);
    elif fu == '/':
        q = OpeartionDiv(numA, numB);
    else:
        print('输入错误');
    print('计算结果：',q.GetResult())

计算器工厂类

#计算器  工厂类
class Operation:
    def __new__(cls):
       pass
    def GetResult(self,numA, numB):
        print('计算2操做数的运算结果')

class OpeartionAdd(Operation):

    def __new__(cls):
        return object.__new__(cls);
        #return  Operation.__new__(cls)

    def GetResult(self,numA,numB):
        return  numA+numB

class OperationSub(Operation):
    def GetResult(self,numA,numB):
        return  numA-numB

class OperationMul(Operation):
    def GetResult(self,numA,numB):
        return  numA*numB
class OperationDiv(Operation):
    def GetResult(self,numA,numB):
        return  numA//numB

class OperationFactory(object):
     #不一样的参数建立不一样的对象的  函数
    def create_class(self,fu):
        if fu == '+':
            q = OpeartionAdd();
        elif fu == '-':
            q = OperationSub();
        elif fu == '*':
            q = OperationMul();
        elif fu == '/':
            q = OperationDiv();
        return q;

if __name__== '__main__':
    #工厂对象
    factory=OperationFactory();
    numA=int(input('请输入第一个操做数'))
    numB=int(input('请输入第二个操做数'))
    fu = input('请输入运算符：')
    # q表明 由 工厂建立出来的一个计算器
    q=factory.create_class(fu)
    print('计算结果：',q.GetResult(numA, numB))

单例模式：该模式主要目的是确保某一个类只有一个实例存在ui

class singleton:
    #借助第三方变量
    __instance=None;
    def __new__(cls, *args, **kwargs):
        if cls.__instance==None:
            cls.__instance=object.__new__(cls);
            return cls.__instance;
        else:
            return cls.__instance;
s=singleton();
print(id(s));
s1=singleton();
print(id(s1));

借助第三方变量更改两个值的位置

a,b=10,5;
c=a;#借助第三方变量更改两个值的位置
a=b;
b=c;
print(a,b);