property的应用
# 例1
# class People:
# def __init__(self, name, height, weight):
# self.name = name
# self.height = height
# self.weight = weight
#
# @property
# def bmi(self):
# return self.weight / (self.height ** 2)
#
#
# p = People('egon', 1.81, 70)
# p.height = 1.84
print(p.bmi())
例2:
class Student:
__school = "oldboy" # _Student__school = "oldboy"
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
stu_obj1 = Student("冯疯子", 18, "female")
stu_obj1.name
# 1在子类派生的新方法中重用父类的功能
# 方式一：指名道姓地调用某一个类的函数
特点：不依赖于继承关系
#
# class OldboyPeople:
# school = "oldboy"
# # 空对象,"艾利克斯",73,'male'
# def __init__(self,name,age,gender):
# self.name = name
# self.age = age
# self.gender = gender
#
# def f1(self):
# print('1111111')
#
# class Student(OldboyPeople):
# # 空对象,"艾利克斯",73,'male',1001,"python全栈开放"
# def __init__(self,name,age,gender,stu_id,course):
# OldboyPeople.__init__(self,name,age,gender) # OldboyPeople.__init__(空对象,"艾利克斯",73,'male')
# self.stu_id = stu_id
# self.course = course
#
#
# def choose(self):
# print('%s 正在选课' %self.name)
#
# def f1(self):
# OldboyPeople.f1(self)
# print("22222")
#
# stu1=Student("艾利克斯",73,'male',1001,"python全栈开放")
# # tea1=Teacher("egon",18,'male',2000,10)
#
#
# stu1.f1()
# 2 在子类派生的新方法中重用父类功能的方式二
# 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
# 特点：严格依赖于继承关系
# class OldboyPeople:
# school = "oldboy"
# # 空对象,"艾利克斯",73,'male'
# def __init__(self,name,age,gender):
# self.name = name
# self.age = age
# self.gender = gender
#
# def f1(self):
# print('1111111')
#
# class Student(OldboyPeople):
# def __init__(self,name,age,gender,stu_id,course):
# # OldboyPeople.__init__(self,name,age,gender) # OldboyPeople.__init__(空对象,"艾利克斯",73,'male')
# super(Student,self).__init__(name,age,gender)
# self.stu_id = stu_id
# self.course = course
#
#
# def choose(self):
# print('%s 正在选课' %self.name)
#
# def f1(self):
# # OldboyPeople.f1(self)
# # super().f1()
# print("22222")
#
# # print(Student.mro())
# stu1=Student("艾利克斯",73,'male',1001,"python全栈开放")
# # print(stu1.__dict__)
# stu1.f1()
#3:
# class A:
# def test(self):
# super().test()
# class B:
# def test(self):
# print('from B')
# class C(A,B):
# pass
# c=C()
# print(C.mro())
# c.test()
# obj=A()
# 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
# 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
# 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__
# 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):
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...')