封裝、反射、裝飾器

####################################################
class foo(object):
    def __init__(self):
        self.func()
    def func(self):
        print('a')
class son(foo):
    def func(self):
        print('b')
son()

class foo(object):
    def __init__(self):
        self.__func()
    def __func(self):
        print('a')
class son(foo):
    def __func(self):      ##會從父類調用__init__
        print('b')

son()

class foo(object):
    def __func(self):
        print('a')
class son(foo):
    def __init__(self):
        self.__func()      #會報錯，私有的內容不能被子類繼承
# son()

#property的使用場景1：和私有的屬性合作，可以查看數據不能修改
class User():
    def __init__(self,user,pwd):
        self.user = user
        self.__pwd = pwd

    @property
    def pwd(self):
        return self.__pwd

alex = User('alex','av')
print(alex.pwd)    

####################################################################
#反射
#
class Test_file():
    l = [('讀文件','read'),('寫文件','write'),('複製文件','copy'),("移動文件",'move')]
    def read(self):
        print('in read file')
    def write(self):
        print('in write file')
    def copy(self):
        print('in copy file')
    def move(self):
        print('in move file')
f = Test_file()
while True:
    for index, opj in enumerate(f.l, 1):
        print(index, opj[0])
    i = int(input("請輸入您要操作的序號："))
    if hasattr(f,opj[i]):
        getattr(f,opj[i])()



###########################
# @classmethod  裝飾器
class goods():
    __discount = 0.8
    def __init__(self):
        self.__price = 5
        self.price = self.__price * self.__discount
    def change_discount(self,new_discount):
        goods.__discount = new_discount

# c = goods()
# print(c.price)

class goods():
    __discount = 0.8
    def __init__(self):
        self.__price = 5
        self.price = self.__price * self.__discount
    @classmethod   #把一個對象綁定的方法，修改成一個類方法
    def change_discount(cls,new_discount):
        cls.__discount = new_discount

c = goods()
print(c.price)