需求：从外网通过VPN访问内网，并登录电脑A。在电脑A通过共享文件夹（需要\\IP的方式访问）访问到内网电脑B，由于电脑B的WI-FI的IP地址会变化，所以当电脑B的I访问路径需要获知电脑B的最新IP

import socket
import smtplib
import json
from email.header import Header
from email.mime.text import MIMEText
from email.utils import parseaddr, formataddr
import threading

now_ip = ""
mail_param_json = ""

# 内网B为win7操作系统，内网IP以10开头，取WIFI-IPdef _get_ip_win():    ips = socket.gethostbyname_ex(socket.gethostname())    for s in ips[2]:        if s.startswith(‘10‘):            return s

#发送邮件到指定的邮箱#配置文件为json字符串：‘{"from_addr": "", "password": "", "to_addr": "", "smtp_server":""}‘def _format_addr(s):    name, addr = parseaddr(s)    return formataddr((Header(name, ‘utf-8‘).encode(), addr))def send_mail(json_param_str=None):    if json_param_str != None and isinstance(json_param_str, str):        e_param = json.loads(json_param_str)        from_addr = e_param.get(‘from_addr‘)        password = e_param.get(‘password‘)        to_addr = e_param.get(‘to_addr‘)        smtp_server = e_param.get(‘smtp_server‘)        msg = MIMEText(‘ip address changed to : ‘ + _get_ip_win() + ‘\r\n‘, ‘plain‘, ‘utf-8‘)        msg[‘From‘] = _format_addr(‘Reboot <%s>‘ % from_addr)        msg[‘To‘] = _format_addr(‘Reboot <%s>‘ % to_addr)        msg[‘Subject‘] = Header(‘NOTICE!!!--PC IP CHANGED‘, ‘utf-8‘).encode()        server = smtplib.SMTP(smtp_server, 25)        server.set_debuglevel(1)        server.login(from_addr, password)        server.sendmail(from_addr, [to_addr], msg.as_string())        server.quit()    else:        pass

#定时检查IP是否有变化def checkIP(start_ip):    global now_ip    if start_ip != now_ip:        global mail_param_json        send_mail(mail_param_json)        print("发送邮件,旧IP：",now_ip,"---新IP：",start_ip)        now_ip = start_ip    else:        print("IP地址未发生变化,旧IP：", start_ip, "---新IP：", now_ip)    new_ip = _get_ip_win()    t = threading.Timer(3600.0, checkIP,(new_ip,))    t.start()

#初始化 读取配置文件if __name__ == ‘__main__‘:    with open(‘./config‘, ‘r‘) as f:        mail_param_json = f.read()    start_ip,now_ip = _get_ip_win(),_get_ip_win()    checkIP(start_ip)