ShoppingCart.py with two methods to add and remove items and inheritance to for one of the Andela Home Study Exercise.

shoppingcart.py

class ShoppingCart:
    def __init__(self):
        self.total = 0
        self.items = {}

    def add_item(self, item_name, quantity, price):
        self.total += price * quantity
        self.items.update({item_name: quantity})

    def remove_item(self, item_name, quantity, price):
        self.total -= price * quantity
        if quantity > self.items[item_name]:
            self.items.pop(item_name)
        else:
            self.items[item_name] -= quantity

    def output(self):
        print("Total: ", self.total)
        print(self.items)

    def checkout(self, cash_paid):
        if self.total > cash_paid:
            return "Cash paid not enough"
        return cash_paid - self.total


class Shop(ShoppingCart):
    def __init__(self):
        super().__init__()
        self.quantity = 100

    def remove_item(self, item_name="", quantity=0, price=0):
        if item_name == "" or quantity == 0 or price == 0:
            self.quantity -= 1
        else:
            super().remove_item(item_name, quantity, price)

    def print_qty(self):
        print("Quantity: ", self.quantity)


# myCart = ShoppingCart()
#
# myCart.add_item("Test", 4, 100)
# myCart.add_item("Test1", 4, 150)
# myCart.add_item("Test2", 4, 180)
#
# myCart.remove_item("Test", 1, 50)
# myCart.remove_item("Test2", 3, 50)
#
# print("Balance: ", myCart.checkout(5000))

myCart = Shop()

myCart.add_item("Test", 4, 100)
myCart.add_item("Test1", 4, 150)
myCart.add_item("Test2", 4, 180)

myCart.remove_item("Test", 1, 50)
myCart.remove_item("Test2", 3, 50)

myCart.print_qty()

myCart.remove_item()
myCart.print_qty()

myCart.remove_item()
myCart.print_qty()

myCart.remove_item()
myCart.print_qty()

myCart.remove_item()
myCart.print_qty()

print("Balance: ", myCart.checkout(5000))

myCart.output()

You are the man.