Python Practice Problems

Load Products from CSV

Create a function load_products(filename) that:

• Uses Python's csv module with context manager (with statement)
• Returns a list of dictionaries, each representing a product
• Converts numeric fields (cost_price, sell_price, stock, reorder_level) to integers

def load_products(filename):
    """Load product data from CSV file using csv module."""
    # Must use: with open(), csv.DictReader()
    # Return: list of dicts with proper type conversion
    pass

Load Suppliers from JSON

Create a function load_suppliers(filename) that:

• Uses Python's json module with context manager
• Returns the suppliers list from the JSON data

def load_suppliers(filename):
    """Load supplier data from JSON file."""
    # Must use: with open(), json.load()
    pass

Calculate Profit Margins

Create a function calculate_profit(product) that:

• Takes a product dictionary as input
• Returns a tuple: (profit_per_unit, profit_margin_percent, total_potential_profit)
• Profit margin = ((sell_price - cost_price) / cost_price) * 100
• Total potential profit = profit_per_unit × stock

def calculate_profit(product):
    """Return tuple: (profit_per_unit, margin_percent, total_profit)"""
    # Must return a TUPLE (not list, not dict)
    pass

Get Unique Categories (Using Set)

Create a function get_unique_categories(products) that:

• Uses a set to find all unique product categories
• Must use set comprehension
• Returns a sorted list of unique categories

def get_unique_categories(products):
    """Return sorted list of unique categories using set comprehension."""
    # Must use: set comprehension {... for ... in ...}
    pass

Find Low Stock Items

Create a function get_low_stock_items(products) that:

• Finds products where stock <= reorder_level
• Must use list comprehension with condition
• Returns list of tuples: (product_id, name, stock, reorder_level)

def get_low_stock_items(products):
    """Return low stock items using list comprehension."""
    # Must use: list comprehension with if condition
    pass

Group Products by Category (Dictionary)

Create a function group_by_category(products) that:

• Creates a dictionary with category names as keys
• Values are lists of product dictionaries in that category
• Must use loops and dictionary operations

def group_by_category(products):
    """Return dict with category as key, list of products as value."""
    # Example: {"Electronics": [product1, product2, ...], ...}
    pass

Get Top Profitable Products

Create a function get_top_products(products, n=5) that:

• Sorts products by total potential profit (descending)
• Uses sorted() with a lambda function as key
• Returns top N products as list of tuples: (name, total_profit)

def get_top_products(products, n=5):
    """Return top N products by profit using sorted() with lambda."""
    # Must use: sorted(products, key=lambda ...)
    pass

Find Suppliers for Category

Create a function find_suppliers_for_category(suppliers, category) that:

• Finds all suppliers that serve the given category
• Category must be in supplier's "categories" list
• Returns list of supplier names, sorted by rating (highest first)

Process Sale Transaction

Create a function process_sale(products, product_id, quantity) that:

• Finds the product by ID in the products list
• Checks if sufficient stock is available
• If yes: reduces stock, returns tuple (True, total_sale_amount, profit)
• If no: returns tuple (False, 0, 0)
• Uses if/elif/else control flow properly

Generate Inventory Report (Text File)

Create a function generate_text_report(products, suppliers, filename) that:

• Uses context manager (with) to write to a text file
• Includes: header with date, inventory summary, low stock alerts, category breakdown, top products
• Uses proper string formatting

Export Updated Inventory to CSV

Create a function save_products_csv(products, filename) that:

• Uses csv.DictWriter to write products back to CSV
• Preserves the same column order as the original file
• Uses context manager for file handling

Main Program

Create a main() function that:

• Loads products from CSV and suppliers from JSON
• Prints inventory statistics to console
• Simulates 3 sale transactions (you choose product_ids and quantities)
• Generates the text report
• Saves updated inventory to a new CSV file
• Uses the if __name__ == "__main__": pattern

def main():
    # Load data
    products = load_products("products.csv")
    suppliers = load_suppliers("suppliers.json")
    
    # Display stats
    print(f"Loaded {len(products)} products")
    print(f"Categories: {get_unique_categories(products)}")
    
    # Process sales
    process_sale(products, "P001", 2)
    process_sale(products, "P005", 1)
    process_sale(products, "P010", 5)
    
    # Generate outputs
    generate_text_report(products, suppliers, "inventory_report.txt")
    save_products_csv(products, "updated_inventory.csv")
    
    print("Inventory system complete!")

if __name__ == "__main__":
    main()