# coding=utf-8

import subprocess

import re

def get_Local_ipv6_address():

    """

    This function will return your local machine's ipv6 address if it exits.

    If the local machine doesn't have a ipv6 address,then this function return None.

    This function use subprocess to execute command "ipconfig", then get the output

    and use regex to parse it ,trying to  find ipv6 address.

    """

    getIPV6_process = subprocess.Popen("ipconfig", stdout = subprocess.PIPE)

    output = (getIPV6_process.stdout.read())

    ipv6_pattern='(([a-f0-9]{1,4}:){7}[a-f0-9]{1,4})'

    m = re.search(ipv6_pattern, str(output))

    if m is not None:

        return m.group()

    else:

        return None

print(get_Local_ipv6_address())