from math import pi
class Circle:
def __init__(self,r):
self.r = r
@property
def area(self):
return self.r*self.r*pi
@property
def perimeter(self):
return self.r*pi*2
c1 = Circle(5)
print(c1.area) # 就是沒有括號了而已
print(c1.perimeter)
class Person:
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)
li = Person('sunv',1.75,85)
# print(li.bmi()) # 報錯,不能加括號了,已變成屬性,不再是方法
print(li.bmi) #27.76
class Goods:
__discount = 0.8 #靜態屬性
def __init__(self,name,price):
self.__name = name
self.__price = price # 原價
@property
def price(self): # 折後價
return self.__price * Goods.__discount
@price.setter
def price(self,new_price): #修改原價 這裏只能傳一個參數(new_price)
self.__price = new_price
apple = Goods('蘋果',10)
apple.price = 9 #settrt 有了settrt 就可以 改屬性了,成真屬性了
print(apple.price) #property
class Goods:
__discount = 0.8 #靜態屬性
def __init__(self,name,price):
self.__name = name
self.__price = price #原價
@property
def name(self):
return self.__name
@name.setter
def name(self,new_name):
self.__name = new_name
@property
def price(self): #折後價
return self.__price * Goods.__discount
@price.setter
def price(self,new_price): #修改原價
if type(new_price) is int:
self.__price = new_price
apple = Goods('蘋果',10)
apple.price = 9 #settrt # 有了settrt 就可以 改屬性了,成真屬性了
print(apple.price) #property # 7.2
apple.name = '富士'
print(apple.name) # 富士
class Foo:
@property
def AAA(self):
print('get的時候運行我啊')
@AAA.setter
def AAA(self,value):
print('set的時候運行我啊')
@AAA.deleter
def AAA(self):
print('delete的時候運行我啊')
#只有在屬性AAA定義property後才能定義AAA.setter,AAA.deleter
f1=Foo()
f1.AAA #property # get的時候運行我啊
f1.AAA='aaa' #setter # set的時候運行我啊 一這樣就觸發setter
del f1.AAA #deleter # delete的時候運行我啊
class Goods:
__discount = 0.8 #靜態屬性
def __init__(self,name,price):
self.__name = name
self.__price = price #原價
@property
def name(self):
return self.__name
@name.setter
def name(self,new_name):
self.__name = new_name
@name.deleter # 若沒有deleter 則下面的調用就會報錯!
def name(self): # AttributeError: can't delete attribute
del self.__name
@property
def price(self): #折後價
return self.__price * Goods.__discount
@price.setter
def price(self,new_price): #修改原價
if type(new_price) is int:
self.__price = new_price
apple = Goods('蘋果',10)
# del apple.name
print(apple.name) # 因爲刪了,所以報錯
從前慢 --- 洪塵