We were presented with a bunch of numbers like this.

This one was just a simple decimal to character conversion:

import sys

f = open(sys.argv[1], "r")
string = f.read()
array = string.rsplit(' ', 5000)

for z in range(len(array)):
    sys.stdout.write(chr(int(array[z], 10)))

sys.stdout.write('\n')
sys.stdout.flush()

Running this script yielded a text about ascii which contained the flag:

Flag