5:00 PM – Python Object Oriented Programming – Sebastian

Today We Did

1. Reviewed homework
2. Spent a lot of time understanding the pro’s and con’s of attributes vs using the variables we learned about in the beginning of class “local variables”
3. Reviewed the core concepts of object oriented programming before moving on to inheritance (coming up next week)
4. In case you need anything, feel free to email me at sebastian@ayclogic.com

Homework

1. Name your homework JUN13_supermarket_hw, please submit by next Monday.
2. Homework: Given the code that we have, finish up the rest of the ShoppingCartApplication class by adding the correct print statements where the comments specify.

   from groceryitem import GroceryItem
   
   
   class ShoppingCartApplication:
   
       def __init__(self):
           self.menu = """
   What do you want to purchase:
   1. Milk - $5
   2. Eggs - $4
   3. Orange Juice - $6
   4. I am done, checkout please
   Enter your selection: """
           # List of GroceryItem
           self.shopping_cart = []
           # Dictionary mapping selection to GroceryItem
           self.menu_items = {
               "1": GroceryItem("Milk", 5, True),
               "2": GroceryItem("Eggs", 4, True),
               "3": GroceryItem("Orange Juice", 6, False)
           }
   
       def check_out(self):
           cost = 0
           for grocery_obj in self.shopping_cart:
               if grocery_obj.is_frozen:
                   pass  # Should print "Frozen grocery item: Milk"
               else:
                   pass  # Should print "Normal grocery item: Orange Juice"
               cost += grocery_obj.price
           print("total cost:", cost)
   
       def application_loop(self):
           while True:
               selection = input(self.menu)
               if selection not in ["1", "2", "3", "4"]:
                   print("Invalid selection")
               elif selection == "4":
                   break
               else:
                   grocery_obj = self.menu_items[selection]
                   self.shopping_cart.append(grocery_obj)
           self.check_out()
   
   
   cart = ShoppingCartApplication()
   cart.application_loop()