Build an inventory tracker

Building an inventory tracker involves creating a system that helps manage and monitor stock levels, product movements, and reorder points. Below is a comprehensive guide and sample implementation of a basic inventory tracker, suitable for a small business or personal use. The example will include key features like adding items, updating stock, viewing inventory, and tracking product details.

Key Features of an Inventory Tracker

• Add new items to inventory

• Update stock quantities (increase/decrease)

• View current inventory status

• Search for specific items

• Track item details like name, SKU, quantity, price, and reorder level

• Alerts for low stock (optional)

Technology Choices

You can build an inventory tracker in many ways:

• Spreadsheet (Excel, Google Sheets) — simplest form

• Desktop app (Python, C#, Java)

• Web app (JavaScript, PHP, Python with Flask/Django, Node.js)

• Database integration for larger scale

For demonstration, here’s a simple inventory tracker built with Python using a CSV file as a data store, which is easy to run and expand.

Inventory Tracker in Python

python
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import csv
import os

INVENTORY_FILE = 'inventory.csv'

# Ensure inventory file exists with headers
def initialize_inventory():
    if not os.path.isfile(INVENTORY_FILE):
        with open(INVENTORY_FILE, mode='w', newline='') as file:
            writer = csv.writer(file)
            writer.writerow(['SKU', 'Name', 'Quantity', 'Price', 'ReorderLevel'])

# Add a new item to inventory
def add_item():
    sku = input("Enter SKU (unique code): ").strip()
    name = input("Enter product name: ").strip()
    quantity = int(input("Enter quantity: "))
    price = float(input("Enter price per unit: "))
    reorder_level = int(input("Enter reorder level: "))

    # Check if SKU already exists
    inventory = load_inventory()
    if sku in inventory:
        print("Error: SKU already exists.")
        return

    with open(INVENTORY_FILE, mode='a', newline='') as file:
        writer = csv.writer(file)
        writer.writerow([sku, name, quantity, price, reorder_level])
    print(f"Item '{name}' added successfully.")

# Load inventory into a dict keyed by SKU
def load_inventory():
    inventory = {}
    with open(INVENTORY_FILE, mode='r') as file:
        reader = csv.DictReader(file)
        for row in reader:
            sku = row['SKU']
            inventory[sku] = {
                'Name': row['Name'],
                'Quantity': int(row['Quantity']),
                'Price': float(row['Price']),
                'ReorderLevel': int(row['ReorderLevel'])
            }
    return inventory

# Update stock quantity (increase or decrease)
def update_stock():
    sku = input("Enter SKU to update: ").strip()
    inventory = load_inventory()

    if sku not in inventory:
        print("SKU not found.")
        return

    print(f"Current quantity for {inventory[sku]['Name']}: {inventory[sku]['Quantity']}")
    change = int(input("Enter quantity to add (+) or remove (-): "))

    new_quantity = inventory[sku]['Quantity'] + change
    if new_quantity < 0:
        print("Error: Quantity cannot be negative.")
        return

    inventory[sku]['Quantity'] = new_quantity
    save_inventory(inventory)
    print(f"Updated quantity for {inventory[sku]['Name']} is now {new_quantity}.")

# Save inventory back to CSV
def save_inventory(inventory):
    with open(INVENTORY_FILE, mode='w', newline='') as file:
        writer = csv.writer(file)
        writer.writerow(['SKU', 'Name', 'Quantity', 'Price', 'ReorderLevel'])
        for sku, data in inventory.items():
            writer.writerow([sku, data['Name'], data['Quantity'], data['Price'], data['ReorderLevel']])

# Display current inventory with low stock alert
def view_inventory():
    inventory = load_inventory()
    print(f"{'SKU':<10} {'Name':<20} {'Quantity':<10} {'Price':<10} {'Reorder Level':<15} {'Status'}")
    print("-" * 70)
    for sku, data in inventory.items():
        status = "OK"
        if data['Quantity'] <= data['ReorderLevel']:
            status = "LOW STOCK"
        print(f"{sku:<10} {data['Name']:<20} {data['Quantity']:<10} {data['Price']:<10.2f} {data['ReorderLevel']:<15} {status}")

# Search for an item by SKU or Name
def search_item():
    term = input("Enter SKU or Name to search: ").strip().lower()
    inventory = load_inventory()
    found = False
    for sku, data in inventory.items():
        if term in sku.lower() or term in data['Name'].lower():
            print(f"SKU: {sku}, Name: {data['Name']}, Quantity: {data['Quantity']}, Price: {data['Price']}, Reorder Level: {data['ReorderLevel']}")
            found = True
    if not found:
        print("No matching items found.")

# Main menu loop
def main():
    initialize_inventory()
    while True:
        print("nInventory Tracker Menu")
        print("1. Add Item")
        print("2. Update Stock")
        print("3. View Inventory")
        print("4. Search Item")
        print("5. Exit")

        choice = input("Choose an option: ").strip()
        if choice == '1':
            add_item()
        elif choice == '2':
            update_stock()
        elif choice == '3':
            view_inventory()
        elif choice == '4':
            search_item()
        elif choice == '5':
            print("Exiting Inventory Tracker.")
            break
        else:
            print("Invalid choice, try again.")

if __name__ == "__main__":
    main()

Explanation

• The script uses a CSV file to store inventory data persistently.

• It initializes the CSV file with headers if it doesn’t exist.

• Users can add new items, update quantities (stock in/out), and view all inventory with alerts on low stock.

• Search functionality helps find items by SKU or name.

• Data validation ensures no negative stock or duplicate SKUs.

How to Use

• Save the script as inventory_tracker.py.

• Run it in a Python environment.

• Follow menu prompts to manage inventory.

Extending the Tracker

• Add date/time logs for stock changes.

• Integrate with barcode scanning.

• Use a database (SQLite, MySQL) for scalability.

• Build a GUI or web interface.

• Automate reorder alerts via email.

This simple yet functional inventory tracker can be your starting point to a more advanced system as your needs grow. If you want, I can help you build a web-based or database-driven version next!