property的应用

# 例1
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# class People:
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#     def __init__(self, name, height, weight):
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#         self.name = name
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#         self.height = height
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#         self.weight = weight
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#
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#     @property
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#     def bmi(self):
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#         return self.weight / (self.height ** 2)
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#
#
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# p = People(‘egon‘, 1.81, 70)
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# p.height = 1.84
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print(p.bmi())

例2:

class Student:
    __school = "oldboy"  # _Student__school = "oldboy"
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    def __init__(obj, x, y, z):
        obj.__name = x
        obj.__age = y
        obj.gender = z
    
    @property
    def name(self):
        print("访问控制")
        return self.__name
    
    @name.setter
    def name(self, x):
        print("赋值控制")
        self.__name = x
    
    @name.deleter
    def name(self):
        print("删除控制")
        del self.__name
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stu_obj1 = Student("冯疯子", 18, "female")
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stu_obj1.name

# 1\在子类派生的新方法中重用父类的功能
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# 方式一：指名道姓地调用某一个类的函数
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特点：不依赖于继承关系

#

# class OldboyPeople:
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#     school = "oldboy"
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#     #             空对象,"艾利克斯",73,‘male‘
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#     def __init__(self,name,age,gender):
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#         self.name = name
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#         self.age = age
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#         self.gender = gender
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#
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#     def f1(self):
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#         print(‘1111111‘)
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#
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# class Student(OldboyPeople):
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#     #            空对象,"艾利克斯",73,‘male‘,1001,"python全栈开放"
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#     def __init__(self,name,age,gender,stu_id,course):
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#         OldboyPeople.__init__(self,name,age,gender)  # OldboyPeople.__init__(空对象,"艾利克斯",73,‘male‘)
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#         self.stu_id = stu_id
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#         self.course = course
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#
#
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#     def choose(self):
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#         print(‘%s 正在选课‘ %self.name)
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#
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#     def f1(self):
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#         OldboyPeople.f1(self)
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#         print("22222")
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#
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# stu1=Student("艾利克斯",73,‘male‘,1001,"python全栈开放")
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# # tea1=Teacher("egon",18,‘male‘,2000,10)
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#
#
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# stu1.f1()

# 2 在子类派生的新方法中重用父类功能的方式二
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# 方式一：调用super(自己的类名,self)会返回一个特殊的对象,super(自己的类名,self).属性,会参照属性查找发起的那个类的mro列表去它父类中查找属性
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# 特点：严格依赖于继承关系

# class OldboyPeople:
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#     school = "oldboy"
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#     #             空对象,"艾利克斯",73,‘male‘
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#     def __init__(self,name,age,gender):
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#         self.name = name
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#         self.age = age
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#         self.gender = gender
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#
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#     def f1(self):
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#         print(‘1111111‘)
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#
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# class Student(OldboyPeople):
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#     def __init__(self,name,age,gender,stu_id,course):
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#         # OldboyPeople.__init__(self,name,age,gender)  # OldboyPeople.__init__(空对象,"艾利克斯",73,‘male‘)
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#         super(Student,self).__init__(name,age,gender)
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#         self.stu_id = stu_id
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#         self.course = course
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#
#
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#     def choose(self):
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#         print(‘%s 正在选课‘ %self.name)
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#
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#     def f1(self):
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#         # OldboyPeople.f1(self)
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#         # super().f1()
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#         print("22222")
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#
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# # print(Student.mro())
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# stu1=Student("艾利克斯",73,‘male‘,1001,"python全栈开放")
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# # print(stu1.__dict__)
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# stu1.f1()
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#3:
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# class A:
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#     def test(self):
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#         super().test()
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# class B:
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#     def test(self):
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#         print(‘from B‘)
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# class C(A,B):
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#     pass
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# c=C()
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# print(C.mro())
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# c.test()
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# obj=A()
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# obj.test()

#4:
class A:
    def test(self):
        print(‘A---->test‘)
        super().aaa()
class B:
    def test(self):
        print(‘B---->test‘)

def aaa(self):
    print(‘B---->aaa‘)

class C(A,B):
    def aaa(self):
        print(‘C----->aaa‘)

c=C()
print(C.mro())
c.test()
"""
A---->test
B---->aaa
"""

对象组合

# 组合:把另外一个类的对象赋值给当前对象的属性
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# 组合表达的是一种有的关系

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
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# stu1.course.tell()

for course_obj in tea1.courses:
    course_obj.tell()

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__
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# class People:
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#     def __init__(self, name, age):
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#         self.name = name
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#         self.age = age
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#
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#     def __str__(self):
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#         # print(‘===>‘)
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#         return "<%s:%s>" %(self.name,self.age)
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#
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# obj = People("egon", 18)
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#
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# print(obj)  # print(obj.__str__())
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# 2 __del__
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class People:
    def __init__(self, name, age,f):
        self.name = name
        self.age = age
        self.f = f
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    def __del__(self):
        print(‘===>‘)
        # 回收资源
        self.f.close()
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obj = People("egon", 18,open("a.txt",‘w‘,encoding=‘utf-8‘))
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del obj

print(‘运行完毕...‘)

面向对象高级及一些方法

原文：https://www.cnblogs.com/kylin5201314/p/13511830.html