bruteforce.py

import sys

with open('ch7.bin') as f:
    data = "".join(f.readlines())

    for shift in range(0, 255):
        sys.stdout.write('%d >>> ' % shift)
        for i in range(0, len(data)):
            sys.stdout.write(chr((ord(data[i])+shift) % 255))
        sys.stdout.write('\n')
        sys.stdout.flush()