Python实现自动更改系统用户密码，生成随机密码

  算是一个实用的例子，定制系统任务，并将随机密码上传至日志服务器，实现定期修改密码； 

  部分代码：

#!/usr/bin/env python
#coding:utf-8
import random,string,os,pexpect,time,re
def passwd_Create():                                #生成随机密码
    all_choice = string.ascii_letters+string.digits
    passwd = ''
    for i in range(8):
        passwd += random.choice(all_choice)
    return passwd

def passwd_Change(name,pwd):                         #更改密码
    child = pexpect.spawn('passwd '+name)
    index = child.expect(['New password',pexpect.EOF,pexpect.TIMEOUT])
    if index == 0 :
        child.sendline(pwd)
        time.sleep(2)
        child.sendline(pwd)
        time.sleep(2)
        child.close(force=True)
    else:
        print "expect ERROR"
        child.close(force=True)

def log_Note(name,key):                          #记录日志
    with open('/var/log/passwd','a+') as log:
        counts = time.ctime()+" ["+name+"]"+" password is"+" ["+key+"]"+"
" 
        log.write(counts)

def checkPw(passwd):                              #检测密码的强度
    plen = len(passwd)
    print plen
    chpw1 = re.compile(r'.*[A-Z]+.*')
    chpw2 = re.compile(r'.*[a-z]+.*')
    chpw3 = re.compile(r'.*d{1,}.*')
    chresult1 = chpw1.findall(passwd)
    print "匹配大写字符: ",chresult1
    chresult2 = chpw2.findall(passwd)
    print "小写字符: ",chresult2
    chresult3 = chpw3.findall(passwd)
    print "至少一个数字: ",chresult3
    
    if chresult1 and chresult2 and chresult3:
        print "You will change passwd use this password"
        return 0 
    else: 
        print "password is not safety,will generate a safety passwd"
        return 1

users = ['root','tom','alice']           #系统用户列表

if __name__ == "__main__":
    for i in range(len(users)):
        a = 1
        while a != 0 :
            keys = passwd_Create()
            a = checkPw(keys)
        passwd_Change(users[i],keys)
        log_Note(users[i],keys)