[Python3] Internal IP sender

#!/usr/bin/env python3

# Author: Jen [jen.development@gmail.com]
# Checks the 'internal' IP of the device. If it has changed since the last
# time it was checked, sends an email to a mail address with the new IP.
#
# It was originally designed to use with the RaspberryPi and be able to connect
# to the device in LAN.

import smtplib
import subprocess
import time

def GetInternalIP(interface):
    output=subprocess.check_output(["ifconfig", interface])
    output=output.decode('utf-8')

    # Parse ifconfig output
    lines=output.split("\n")
    ipAddr=lines[1].strip().split("  ")[0].split(":")[1]
    return ipAddr


def SendMail():
    dateAndTime=time.strftime("%A, %d %m %Y %H:%M:%S (%Z)", time.localtime())

    subject="Raspberry Pi event [{}]".format(ipAddr)
    body="Current raspberry IP is: {}\n\n\n{}".format(ipAddr, dateAndTime)

    msg="From: {0}\nTo: {1}\nSubject: {2}\n\n{3}".format(fromAddr, toAddr[0], subject, body)

    # Create SMTP Object
    smtpObj=smtplib.SMTP(smtpServer, smtpPort)

    smtpObj.ehlo() # Identify client
    smtpObj.starttls()
    smtpObj.ehlo() # Identify client under TLS

    smtpObj.login(smtpUser, smtpPass)

    smtpObj.sendmail(fromAddr, toAddr, msg)
    smtpObj.quit()
    return


interface="wlan0"
prevIP=None #NO TOCAR

smtpServer="smtp.gmail.com"
smtpPort=587
smtpUser="tu.correo@gmail.com"
smtpPass="contraseñadelcorreo"

fromAddr="<tu.correo@gmail.com>"
toAddr=["<tu.correo@gmail.com>"]

# Workaround to gain time while some necessary network resources are being prepared
time.sleep(30)

while True:
    ipAddr=GetInternalIP(interface)
    if ipAddr != prevIP:
        SendMail()
        prevIP=ipAddr
    time.sleep(900) # 15 minutes