[root@zijie ~]# cat mysql_random_passowrd.py
#!/usr/bin/python
#-*- coding:utf-8 -*-

import sys
import random

def get_random_password():
    chars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
    pwd_str = ''.join(random.choice(chars) for i in range(18))
    passwd = pwd_str[0:18] + "*" + pwd_str[-1]
    return passwd

user = sys.argv[1]
host = sys.argv[2]
password = get_random_password()
print("create user '%s'@'%s' identified by '%s';"%(user,host,password))

[root@zijie ~]# python mysql_random_passowrd.py zijie %
create user 'zijie'@'%' identified by 'VhFg0LUMIYlT9vgN3q*q';