Reverse and rename files start with "001, 002, ... N-1, N" to "N, N-1, N-2, ..., 002, 001"

reverse_dir.py

import os


def reverse_dir(dirname):
    reverse_d = {v[0]: f'{i + 1:03d}. {v[0][5:]}' for i, v in enumerate(
        sorted({filename: int(filename[:3]) for filename in os.listdir(dirname)}.items(), key=lambda x: x[1],
               reverse=True))}
    for old_filename, new_filename in reverse_d.items():
        print(f'{old_filename} -> {new_filename}')
        os.rename(os.path.join(dirname, old_filename), os.path.join(dirname, new_filename))


reverse_dir('D:\Downloads')