Python3 でランダム文字列作るやつ。

pass_gen.py

#!/usr/bin/env python3

import sys
import random

argv = sys.argv
argc = len(argv)

if argc not in {2, 3}:
    print("Usage: pass_gen digis [mode(1:number,2:lower,4:upper,8:specials]")
    quit()

if argc == 3:
    mode = int(argv[2])
else:
    mode = 1

length = int(argv[1])

seed = ""
if mode & 0x01 == 1:
    seed += "0123456789"

if mode >> 1 & 0x01 == 1:
    seed += "abcdefghijklmnopqrstuvwxyz"

if mode >> 2 & 0x01 == 1:
    seed += "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

if mode >> 3 & 0x01 == 1:
    seed += "!@#$%^&*()_[];:,./<>"

print("".join([random.choice(seed) for x in range(length)]))