Question

我使用python编写了以下脚本：

class Fruit:

  def __init__(self,name):
      self.name = name
      print "Initialized Fruit Name: %s" % self.name

  def tell(self):
      print "U have entered the fruit as %s" % self.name

class Sweet(Fruit):

  def __init__(self,name,taste,price):
      Fruit.__init__(self,name)
      self.taste = taste
      print "Initialized the name of the fruit as %s" % self.name

  def tell(self):
      Fruit.tell(self)
      print "Taste of the fruit is %s" % self.taste

  def sayPrice(self):
      Fruit.tell(self)                 
      print "The price of the fruit Mango is %d" % self.price

class Salt(Fruit):

  def __init__(self,name,taste,price):
      Fruit.__init__(self,name)
      self.taste = taste
      print "Initialized the name of the fruit as %s" % self.name

  def tell(self):
      Fruit.tell(self)
      print "Taste of the fruit is %s" % self.taste

  def sayPrice(self):
      Fruit.tell(self)
      print "The price of the fruit Strawberry is %d" % self.price

m = Sweet('Mango','sweet',100)

s = Salt('Strawberry','salty',50)

choice = raw_input("enter ur choice:(Mango/Strawberry):")

if choice == 'Mango':
    m.tell()
else:
    s.tell()

decision = raw_input("Do U want to know the price?(Y/N)")

if decision == 'Y' and choice == 'Mango':

    m.sayPrice()
elif decision == 'Y' and choice == 'Strawberry':

    s.sayPrice() 
else:
    print "Sad to see U go :(, please do visit next time again"

以下是我得到的错误：

追踪（最近一次呼叫最后一次）：

文件“C：/Python26/Inheritance_practice2.py”，第47行，
m.sayPrice()
文件“C：/Python26/Inheritance_practice2.py”，第21行，在sayPrice
print "The price of the fruit Mango is %d" % self.price
AttributeError：Sweet实例没有属性'price'

注意：当用户想知道价格时，会抛出错误   选择的水果。

Answer 1

self.price=price方法中需要__init__ - 目前您只是抛弃了该参数。

Answer 2

您需要添加self.price，最好添加到Fruit：

class Fruit:
    def __init__(self,name,price):
        self.name = name
        self.price = price #set price when initiated.
        (...)

class Sweet(Fruit):
    def __init__(self,name,taste,price):
        Fruit.__init__(self,name,price) #send price as init parameter
        self.taste = taste
        print "Initialized the name of the fruit as %s" % self.name
    (..)

Answer 3

也许是一个更好的选择将该属性添加到您的父类水果

class Fruit:

  def __init__(self,name, price):
      self.name = name
      self.price = price
      print "Initialized Fruit Name: %s" % self.name

  def tell(self):
      print "U have entered the fruit as %s" % self.name

class Sweet(Fruit):

  def __init__(self,name,taste,price):
      Fruit.__init__(self,name, price)
      self.taste = taste
     print "Initialized the name of the fruit as %s" % self.name

  def tell(self):
      Fruit.tell(self)
      print "Taste of the fruit is %s" % self.taste

  def sayPrice(self):
      Fruit.tell(self)                 
      print "The price of the fruit Mango is %d" % self.price

class Salt(Fruit):

  def __init__(self,name,taste,price):
      Fruit.__init__(self,name, price)
      self.taste = taste
      print "Initialized the name of the fruit as %s" % self.name

  def tell(self):
      Fruit.tell(self)
      print "Taste of the fruit is %s" % self.taste

  def sayPrice(self):
      Fruit.tell(self)
      print "The price of the fruit Strawberry is %d" % self.price

也可以正常工作。您还可以在Fruit类中添加一个getter来获取价格，保存代码行并使用OOP给出的优势，因为您的子类继承了该方法

在Python中收到错误'AttributeError：'

3 个答案: