Fill disk with data (Python)

# WARNING: DO NOT RUN THIS SCRIPT unless you know what you are doing
# This script can permanently erase ALL data from your disk

import os
import sys

megs = 4 #MB to write at a time
size = 10 #Number of GB (total) to write to drive

f = os.fdopen(os.open('\\\\.\\PhysicalDrive2',  os.O_WRONLY|os.O_BINARY), 'wb+') #MAKE SURE YOU CHANGE THIS TO THE CORRECT DRIVE
a = bytearray(1048576 * megs)

for x in range(0, 1048576 * megs):
    if x % 4 == 0:
        a[x] = 0xba
    elif x % 4 == 1:
        a[x] = 0xad
    elif x % 4 == 2:
        a[x] = 0xf0
    else:
        a[x] = 0x0d

for x in range(0, int((size * 1024) / megs)):
    if x % megs == 0:
        sys.stdout.write("\r %s MB written" % (x * megs))
    f.seek(x * 1048576 * megs)
    f.write(a)

f.close()