Explain the main objects and their relationships in a traditional retail store system.

In a traditional retail store system, the main objects and their relationships can be described as follows:

• Product — an item for sale with characteristics (name, price, quantity).
• Customer — the buyer who makes purchases.
• Order — a set of products selected by the customer for purchase.
• Employee — serves customers, manages the store.
• Cash Register — the place where payments for orders are made.

Relationships:

• The customer creates an Order by selecting Products.
• The Order is processed by an employee and paid for at the Cash Register.
• The store manages the inventory of Products and serves customers.

Example of simple classes in Python:

class Product:
    def __init__(self, name, price):
        self.name = name
        self.price = price

class Customer:
    def __init__(self, name):
        self.name = name

class Order:
    def __init__(self, customer):
        self.customer = customer
        self.items = []

    def add_product(self, product, quantity):
        self.items.append((product, quantity))

class Employee:
    def __init__(self, name):
        self.name = name

class CashRegister:
    def process_payment(self, order):
        total = sum(product.price * qty for product, qty in order.items)
        print(f"Payment for order amounting to {total} rubles")