getting an error 'AttributeError:' in Python

Question

I have written the below script using python:

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"

And below is the error I am getting:

Traceback (most recent call last):

File "C:/Python26/Inheritance_practice2.py", line 47, in

m.sayPrice()

File "C:/Python26/Inheritance_practice2.py", line 21, in sayPrice

print "The price of the fruit Mango is %d" % self.price

AttributeError: Sweet instance has no attribute 'price'

NOTE: The error is thrown when the user wants to know the price of the chosen fruit.

• jonrsharpe: Please cut this down to a minimal example; we don't need to see everything. But you never assign self.price, so this shouldn't have been surprising.
• Daniel Roseman: And where do you think you are setting the price? Point to the code that does it.
• James Mertz: For the love of all that is pythonic, please wrap up your script code with a if __name__ == "__main__":.
• jonrsharpe: Also, why bother always passing 'salty' to Salt? Surely taste should be a Fruit attribute, then e.g. Salt doesn't take that argument and always passes 'salty' to super(Salt, self).__init__(...)? That way all Fruit has a taste, and all Salt has taste == 'salty'.
• python_beginner: How can I do the wrapping of this code using if ______name______ = "______main______" could you please paste the code here.Thanks.

Answer 1

You need self.price=price in the __init__ methods - currently you are just throwing that parameter away.

Answer 2

You need to add self.price, preferably to 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
 (..)

• Marcin: Strictly not to the classes, but to the instances.

Answer 3

Maybe is a better option add that attribute to you parent class fruit

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

Works fine as well. Also you can add a getter in your Fruit class to obtain the price, saving lines of code and using the advantage given by the OOP because your children classes are inheriting the method