To troubleshoot and improve the reliability of the script, I would first implement error handling using try-except blocks to catch exceptions like FileNotFoundError or ValueError. This would allow the script to provide a user-friendly message if the file is missing or contains invalid data. Additionally, I would add logging to record errors and any relevant information, which would help in diagnosing issues. To further enhance reliability, I would validate the data before processing it, ensuring it meets the expected format and values. Lastly, I would write unit tests to cover different scenarios, which would help in identifying potential issues early in the development process.