(Replace words) Suppose you have a lot of files in a directory that contain words Exercisei_j, where i and j are digits. Write a program that pads a 0 before i if i is a single digit and 0 before j if j is a single digit. For example, the word Exercise2_1 in a file will be replaced by Exercise02_01. In Java, when you pass the symbol * from the command line, it refers to all files in the directory (see Supplement III.V). Use the following command to run your program: java Exercise12_27 *

Certainly, I can help you with that! Here's a Python code snippet that can accomplish the task:

import os

for filename in os.listdir('.'):
    if filename.startswith('Exercise'):
        new_filename = filename.replace('_', '_0')
        new_filename = new_filename[:9] + '0' + new_filename[9:11] + '0' + new_filename[11:]
        os.rename(filename, new_filename)

This code loops through all files in the current directory, and checks if the filename starts with "Exercise". If it does, it replaces the first underscore with "_0". It then inserts a "0" before the first digit (if necessary) and another "0" before the second digit (if necessary). Finally, it renames the file to the new name using the `os.rename()` function. You can run this script by saving it as a .py file and executing it with the command `python filename.py` in the directory with the files.