Project Description¶

In this project, we will create a complete inventory management system for a retail business called ShopSmart. We will apply our knowledge of object-oriented programming (OOP) using Python to build this system. The main goal is to track stock levels, manage orders, monitor sales, and handle deliveries efficiently.

Let’s imagine we are working for a fast-growing online store that sells many types of products such as electronics, clothes, and home goods. As the company grows, managing inventory properly becomes very important for smooth operations and keeping customers happy.

To solve this problem, we will design and develop a system using object-oriented programming. OOP helps us organize code in a modular and reusable way. This makes it easier to manage and scale complex systems like inventory management software.

We will create two main classes: Product and Order. Each class will have specific responsibilities, which are explained below.

Product Class¶

The Product class is responsible for managing product details such as ID, name, category, quantity, price, and supplier. It will also manage the entire product inventory using a class-level variable.

Constructor¶

Parameters: self, product_id, name, category, quantity, price, supplier

Class-level variable¶

  • inventory: This stores all the product records.

Class Methods¶

add_product(cls, name, category, quantity, price, supplier)¶

  • Automatically generates a unique product ID.
  • Creates a new product and adds it to the inventory.
  • Returns: "Product added successfully"

update_product(cls, product_id, quantity=None, price=None, supplier=None)¶

  • Checks if the product ID exists in the inventory.
  • If it does, updates the given attributes.
  • Returns:
    • "Product information updated successfully" if found and updated.
    • "Product not found" if the ID does not exist.

delete_product(cls, product_id)¶

  • Searches for the product by ID in the inventory.
  • If found, deletes it from the inventory.
  • Returns:
    • "Product deleted successfully" if found and removed.
    • "Product not found" if the ID does not exist.

Order Class¶

The Order class will handle order creation and management.

Constructor¶

Parameters: self, order_id, products, customer_info=None

Method¶

place_order(self, product_id, quantity, customer_info=None)¶

  • Adds a product to the order as a tuple of (product_id, quantity).
  • Each order includes only one product.
  • Returns: "Order placed successfully. Order ID: {self.order_id}"

This project will allow us to practice real-world software design by building a system that is clear, reusable, and useful for businesses. It will also help us better understand how object-oriented programming can solve everyday problems in the retail industry.

Let's create Product and Order classes based on the implementation requirements outlined above.¶

In [6]:
class Product:
    inventory = []  # Class-level variable to store all products. This is shared among all instances of Product.

    def __init__(self, product_id, name, category, quantity, price, supplier):
        self.product_id = product_id  # Instance variable to store the product's ID.
        self.name = name  # Instance variable to store the product's name.
        self.category = category  # Instance variable to store the product's category.
        self.quantity = quantity  # Instance variable to store the quantity of the product.
        self.price = price  # Instance variable to store the price of the product.
        self.supplier = supplier  # Instance variable to store the supplier of the product.
        Product.inventory.append(self)  # Add this new product instance to the class-level inventory list.

    @classmethod
    def add_product(cls, name, category, quantity, price, supplier):
        # This is a class method that adds a new product to the inventory.
        product_id = cls.inventory[-1].product_id + 1 if len(cls.inventory)>0 else 1  # Generate a new product ID by counting existing products and adding 1.
        new_product = cls(product_id, name, category, quantity, price, supplier)  # Create a new product instance.
        return "Product added successfully"  # Return a confirmation message.

    @classmethod
    def update_product(cls, product_id, quantity=None, price=None, supplier=None):
        # This class method updates the details of an existing product.
        for product in cls.inventory:  # Loop through the inventory to find the product with the given ID.
            if product.product_id == product_id:  # Check if this is the product we want to update.
                if quantity is not None:  # If a new quantity is provided, update it.
                    product.quantity = quantity
                if price is not None:  # If a new price is provided, update it.
                    product.price = price
                if supplier is not None:  # If a new supplier is provided, update it.
                    product.supplier = supplier
                return "Product information updated successfully"  # Return a confirmation message.
        return "Product not found"  # If the product ID was not found, return this message.

    @classmethod
    def delete_product(cls, product_id):
        # This class method deletes a product from the inventory.
        for i, product in enumerate(cls.inventory):  # Loop through the inventory with index to find the product.
            if product.product_id == product_id:  # Check if this is the product we want to delete.
                del cls.inventory[i]  # Delete the product from the inventory list.
                return "Product deleted successfully"  # Return a confirmation message.
        return "Product not found"  # If the product ID was not found, return this message.
In [7]:
class Order:
    def __init__(self, order_id, products, customer_info=None):
        self.order_id = order_id  # Instance variable to store the order's ID.
        self.products = products  # Instance variable to store the list of products in the order. Each product is represented as a tuple (product_id, quantity).
        self.customer_info = customer_info  # Instance variable to store optional customer information.

    def place_order(self, product_id, quantity, customer_info=None):
        # This method adds a product to the order.
        for product in Product.inventory:
            if product.product_id == product_id and product.quantity >= quantity: # Check that the product exist in the inventory and that there's stock
                product.quantity -= quantity  # Update the stock of the product by reducing it by the ordered quantity
                self.products.append((product_id, quantity))  # Add the product and quantity as a tuple to the order's products list.
                if customer_info:  # If customer information is provided, update it.
                    self.customer_info = customer_info
                return f"Order placed successfully. Order ID: {self.order_id}"  # Return a confirmation message with the order ID.
        return "Order could not be placed. Product not found or insufficient quantity."