A script for making a file of a given size

makefile.py

import sys

if len(sys.argv) != 3:
    print 'Incorrect number of arguments; provide the file-name followed by the file-size.\ne.g. you can make a 1 GB file named "newfile" by calling:\n\n    %s newfile 1073741824' % (sys.argv[0])
    exit()

filename = sys.argv[1]
size = int(sys.argv[2])

with open(filename, "wb") as f:
    f.seek(size - 1)
    f.write(b"\0")
    f.close()