Instead of opening files in a+ mode, you should use r+ mode to properly handle both reading and writing. Before performing a read operation, use seek(0) to reset the file pointer to the beginning; otherwise, read() may return an empty value. When comparing the read data, use .strip() to remove unnecessary spaces. Additionally, during the registration process, clearing the file content with truncate() before writing new entries will prevent old data from persisting. These changes will ensure that the login and registration functions work correctly without errors.