面向对象编程之——继承（组合，多态，一切皆对象，面向对象高级之内置函数&方法，反射）

一、组合

组合:把另外一个类的对象赋值给当前对象的属性
组合表达的是一种有的关系
ps: 继承：is-a
　　 组合：has-a
　　多态：归一化，通过继承实现

class Teacher:
    def __init__(self, name, age, gender, level):
        self.name = name
        self.age = age
        self.gender = gender
        self.level = level

    def tell(self):
        print("%s:%s" % (self.name, self.age))


class Student:
    def __init__(self, name, age, gender):
        self.name = name
        self.age = age
        self.gender = gender


class Course:
    def __init__(self, name, price, period):
        self.name = name
        self.price = price
        self.period = period

    def tell(self):
        print('<%s:%s:%s>' % (self.name, self.price, self.period))


tea1 = Teacher("egon", 18, "male", 10)
stu1 = Student("xxx", 19, "male")

python = Course("python开放", 30000, "3mons")
linux = Course("linux课程", 30000, "3mons")

tea1.courses = [python,linux]
stu1.course = python

# tea,stu  # 超级对象

# stu1.course.tell()
for course_obj in tea1.courses:
    course_obj.tell()

二、多态

同一种事物有多种形态
例如:动物这种事物有多种形态,如人\狗\猪
特性: 我们可以在不考虑某一个对象具体类型的前提下,直接使用该对象

1、父类有的功能,子类一定有

# import abc
#
# class Animal(metaclass=abc.ABCMeta):
#     @abc.abstractmethod
#     def speak(self):
#         pass
#
#     @abc.abstractmethod
#     def run(self):
#         pass
#
# # Animal()  # Animal的作用是用来制定标准的
#
# class People(Animal):
#     def speak(self):
#         print("啊啊啊啊")
#
#     def run(self):
#         print("咻咻咻...")
#
# class Dog(Animal):
#     def giao(self):
#         print("汪汪汪")
#
# class Pig(Animal):
#     def heheng(self):
#         print("哼哼哼")

# peo1=People()
# d1=Dog()
# p1=Pig()

# peo1.jiao()
# d1.giao()
# p1.heheng()




# peo1.speak()
# d1.speak()
# p1.speak()

# def speak(animal):
#     animal.speak()
#
# speak(peo1)
# speak(d1)
#
# speak(p1)

2、鸭子类型:duck

# class People:
#     def speak(self):
#         print("啊啊啊啊")
#
#     def run(self):
#         print("咻咻咻...")
#
# class Dog:
#     def speak(self):
#         print("汪汪汪")
#
#     def run(self):
#         print("狂奔...")
#
# class Pig:
#     def speak(self):
#         print("哼哼")
#
#     def run(self):
#         print("咣咣咣...")
#
#
# peo1=People()
# d1=Dog()
# p1=Pig()


# peo1.run()
# d1.run()
# p1.run()

 

class Cpu:
    def read(self):
        pass

    def write(self):
        pass

class Process:
    def read(self):
        pass

    def write(self):
        pass

class Disk:
    def read(self):
        pass

    def write(self):
        pass

三、一切皆对象

数据类型 == 类

# x = 11  # x=int(11)
# print(int)

# class Foo:
#     pass
# print(Foo)

x = [1,2,3]  # list([1,2,3])
y = [111,222]  # list([1,2,3])
# x.append(4)
# y.append(3333)

# list.append(x,4)
# list.append(y,333)

# print(x)
# print(y)

print(type(x))

四、面向对象高级

1、内置函数

is   
isinstance判断类型
 issubclass判断是否是子类

x = 111

print(type(x) is int)

print(isinstance(x,int))

class Bar:
    pass

class Foo(Bar):
    pass
print(issubclass(Foo,Bar))

2、内置方法

内置方法都是在满足某种条件下自动触发的
（1）__str__

class People:
    def __init__(self, name, age):
        self.name = name
        self.age = age

    def __str__(self):
        # print('===>')
        return "<%s:%s>" %(self.name,self.age)

obj = People("egon", 18)

print(obj)  # print(obj.__str__())

（2）__del__

class People:
    def __init__(self, name, age,f):
        self.name = name
        self.age = age
        self.f = f

    def __del__(self): #注意运行顺序
        print('===>')
        # 回收资源
        self.f.close()

obj = People("egon", 18,open("a.txt",'w',encoding='utf-8'))

del obj
# print('运行完毕...') 

五、反射

反射：获取程序里的对象，并且把它取出来

dir(对象)

hasattr
getattr
setattr
delattr

用法举例：

 

class BlackMedium:
    feature='Ugly'
    def __init__(self,name,addr):
        self.name=name
        self.addr=addr

    def sell_house(self):
        print('%s 黑中介卖房子啦,傻逼才买呢,但是谁能证明自己不傻逼' %self.name)
    def rent_house(self):
        print('%s 黑中介租房子啦,傻逼才租呢' %self.name)

b1=BlackMedium('万成置地','回龙观天露园')

#检测是否含有某属性
print(hasattr(b1,'name'))
print(hasattr(b1,'sell_house'))

#获取属性
n=getattr(b1,'name')
print(n)
func=getattr(b1,'rent_house')
func()

# getattr(b1,'aaaaaaaa') #报错
print(getattr(b1,'aaaaaaaa','不存在啊'))

#设置属性
setattr(b1,'sb',True)
setattr(b1,'show_name',lambda self:self.name+'sb')
print(b1.__dict__)
print(b1.show_name(b1))

#删除属性
delattr(b1,'addr')
delattr(b1,'show_name')
delattr(b1,'show_name111')#不存在,则报错

print(b1.__dict__)

 

 

 

class Foo:
    def __init__(self, x, y):
        self.x = x
        self.y = y

    def f1(self):
        print('from f1')


obj = Foo(111, 222)



#反射
# res = dir(obj)
# print(res)
# print(obj.__dict__[res[-1]])

# print(obj.__dict__['x'])
# import re
#
# for attr in dir(obj):
#     if not re.search("^__.*__$",attr):
#         res=getattr(obj,attr)
#         print(res)


# print(hasattr(obj,'x'))
# print(getattr(obj,'xxx',None))  # obj.xxx
# setattr(obj,"xxx",1111)  # obj.xxx = 1111
#
# delattr(obj,"xxx")  # del obj.xxx


# m=__import__("time")
# m.sleep(3)

# getattr(m,'sleep')(3)

 

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