Sign-up: Allows users to create new accounts with usernames and passwords, storing them securely in the "user_data.csv" file using bcrypt for password hashing.

Login: Enables users to enter their existing usernames and passwords, validating them against the stored data and granting access on successful login.

Error Handling: Incorporates exception handling to gracefully address issues like invalid inputs, file access errors, and unexpected exceptions.

Readability: Enhances code clarity with clear variable names, comments, and well-defined functions.

Efficiency: Streamlines the code, removing redundancies and optimizing logic for better performance. Improvements:

Security: Implements secure password hashing with bcrypt, significantly improving password protection.

Structure: Organizes the code into modular functions for maintainability and clarity.