import os def modify_file(input_filename, output_filename): """ Reads a file, modifies each line by adding a line number, and writes the modified content to a new file. Handles potential file_related errors.'"" try: with open(input_filename, 'r')as infile,open(output_filename, 'w') as outfile: for i, line in enumerate(infile): modified_line=f"{i+1}: {line}" outfile.write(modified_line) print(f"successfully modified '{input_filename}' and wrote to '{output_filename}'") except FileNotFoundError: print(f"Error: The file '{input_filename}' was not found.") except Exception as e: print(f"An unexpectederror occured:{e}")

def main(): """ prompts the user for an input filename,output filename, and calls the modify_file function to process the files.

""" input_filename=input("Enter the input filename: ") output_filename=input("Enter the output filename: ") modify_file(input_filename, output_filename) if_name_=="'main":

main()