Computer Science – 20.2 File Processing and Exception Handling | e-Consult

Model Answer 2

This solution uses the csv module to read and write CSV files, performing calculations on the data.

import csv

def calculateproductrevenue(inputfilename, outputfilename):

product_revenue = {}

try:

with open(input_filename, 'r', newline='') as infile:

reader = csv.reader(infile)

header = next(reader) # Skip the header row

for row in reader:

product_name, quantity, price = row

try:

quantity = int(quantity)

price = float(price)

except ValueError:

print(f"Warning: Invalid data in row: {row}. Skipping.")

continue

revenue = quantity * price

if productname in productrevenue:

productrevenue[productname] += revenue

else:

productrevenue[productname] = revenue

except FileNotFoundError:

print(f"Error: File '{input_filename}' not found.")

return

try:

with open(output_filename, 'w', newline='') as outfile:

writer = csv.writer(outfile)

writer.writerow(["Product Name", "Total Revenue"]) # Write header

for product, revenue in product_revenue.items():

writer.writerow([product, revenue])

except Exception as e:

print(f"Error writing to file '{output_filename}': {e}")

if name == "main":

inputfile = "salesdata.csv"

outputfile = "productrevenue.csv"

calculateproductrevenue(inputfile, outputfile)

Explanation:

• The code uses the csv module to read the input CSV file.
• It skips the header row.
• For each row, it extracts the product name, quantity, and price.
• It calculates the revenue for that sale.
• It aggregates the revenue for each product in the product_revenue dictionary.
• Finally, it writes the product names and their total revenue to the output CSV file.
• Error handling is included for file not found and invalid data in the input file.