This is what i tried, it should help
class ShoppingCart: items = {} totals = [] def __init__(self, total=0): self.total = total self.items = {} def add_item(self, item_name, quantity, price): self.item_name = item_name self.quantity = quantity self.price = price self.total += price * quantity self.items.update({item_name : quantity}) def remove_item(self, item_name, quantity, price): self.item_name = item_name self.quantity = quantity self.price = price if item_name in self.items: if quantity < self.items[item_name] and quantity > 0: self.items[item_name] -= quantity self.total -= price * quantity elif quantity >= self.items[item_name]: self.total -= price * self.items[item_name] del self.items[item_name] def checkout(self, cash_paid): self.cash_paid = cash_paid if cash_paid >= self.total: return cash_paid - self.total return "Cash paid not enough" class Shop(ShoppingCart): def __init__(self): self.quantity = 100 def remove_item(self): self.quantity -= 1