class Room:

    def __init__(self,name,length,width):

        self.__name = name

        self.__length = length

        self.__width = width

    def get_name(self):

        return self.__name

    def set_name(self,newName):

        if type(newName) is str and newName.isdigit() == False:

            self.__name = newName

    def area(self):

        return  self.__length * self.__width

jin = Room('金老板',2,1)

print(jin.area())

jin.set_name('')

print(jin.get_name())

# property 内置装饰器函数，只在面向对象中使用

from math import  pi

class Circle:

    def __init__(self,r):

        self.r = r

    @property

    def perimeter(self):

        return 2*pi*self.r

    @property

    def area(self):

        return self.r**2*pi

c1 = Circle(5)

print(c1.area)  #圆的面积

print(c1.perimeter)   #圆的周长

78.53981633974483

31.41592653589793

class Person:

    def __init__(self,name):

        self.__name = name

    @property

    def name(self):

        return self.__name + 'sb'

    @name.setter

    def name(self,new_name):

        self.__name = new_name

tiger = Person('tim')

print(tiger.name)

tiger.name = '全班'

print(tiger.name)

timsb

全班sb

class Goods:

    discount = 0.8

    def __init__(self,name,price):

        self.name = name

        self.__price = price

    @property

    def price(self):

        return self.__price * Goods.discount

apple = Goods('apple',5)

print(apple.price)

#删除属性

class Person:

    def __init__(self,name):

        self.__name = name

    @property

    def name(self):

        return self.__name

    @name.deleter

    def name(self):

        del self.__name

teng = Person('tim')

print(teng.name)

del teng.name

print(teng.name)

class Goods:

    __discount = 0.8

    def __init__(self,name,price):

        self.name = name

        self.__price = price

    @property

    def price(self):

        return self.__price * Goods.__discount

    @classmethod   #把一个方法变成一个类中的方法，这个方法就直接可以被类调用，不需要依托任何对象

    def change_discount(cls,new_discount):  #修改折扣

        cls.__discount = new_discount

apple = Goods('apple',5)

print(apple.price)

Goods.change_discount(0.5)

print(apple.price)

#当这个方法的操作，只涉及静态属性的时候，就应该使用classmethod

4.0

2.5

# staticmethod

class Login:

    def __init__(self,name,password):

        self.name = name

        self.pwd = password

    def login(self):pass

    @staticmethod

    def get_usr_pwd():

        usr = input('用户名: ')

        pwd = input('密码： ')

        Login(usr,pwd)

Login.get_usr_pwd()

#在完全面向对象的过程中

# 如果一个函数，既和对象没有关系，也和类没有关系，那么就用staticmethod将这个函数变成一个静态方法

# 类方法和静态方法，都是类调用的
# 对象可以调用类方法和静态方法 ，一般情况下，推荐用类名调用
# 类方法 有个默认参数 cls 代表这个类 
# 静态方法 没有默认的参数 就像函数一样

class Teacher:

    dic = {'查看学生信息':'show_student','查看讲师信息':'show_teacher'}

    def show_student(self):

        print('show_student')

    def show_teacher(self):

        print('show_teacher')

    @classmethod

    def func(cls):

        print('haha')

tim = Teacher()

for k in Teacher.dic:

    print(k)

key = input('pls input :')

# print(Teacher.dic[key])

func = getattr(tim,Teacher.dic[key])

func()

# tim = Teacher()

# tim.show_student()

# func = getattr(tim,'show_student')

# func()

# hasattr()  getattr()  delattr()

# if hasattr(Teacher,'dic'):

#     ret = getattr(Teacher,'dic')  #Teacher.dic

# ret = getattr(Teacher,'dic')  #Teacher.dic

# ret2 = getattr(Teacher,'func')

# ret2()

#     print(ret)