import subprocess
# Subprocess is a module allows us to execute system commands.
# Commands depend on the OS which executes the script.
# E.g: subprocess.call("cmd",Shell=True)
#      subprocess.call(["cmd","arg1","arg2"])

import optparse
# Optparse is used for handling cmd line arguments

import re
# This is a regix module

def get_arguments():
    parser = optparse.OptionParser()
    parser.add_option("-i","--interface", dest="interface",help="Interface to change MAC for.")
    parser.add_option("-m","--mac", dest="address",help="New MAC address")
    parser.add_option("-r","--result",dest="result",help="Set to 1 if you want to see the result")
    (options, args) = parser.parse_args()
    
    interface = options.interface
    address = options.address
    result = options.result
    
    if not interface:
        parser.error("[-] Please check if the interface is specified\n")
    elif not address:
        parser.error("[-] Please check if the MAC is specified\n")
    
    return interface,address,result


def checkIfMACChanged(interface,address):
    ipRes = subprocess.check_output(["sudo","ip","link","show",interface])
    return re.search(r"\w\w:\w\w:\w\w:\w\w:\w\w:\w\w",ipRes).group(0) == address 
    



def changeMAC(interface,address,ifShowRes="0"):

    #print "SHUTTING DOWN ETH0"
    #subprocess.call("sudo ip link set dev " + interface + " down ",shell=True)
    subprocess.call(["sudo","ip","link","set","dev",interface,"down"])



    #print "CHANGING THE MAC TO 00:22:33:44:55:66"
    #subprocess.call("sudo ip link set dev "+ interface +" address " + address,shell=True)
    subprocess.call(["sudo","ip","link","set","dev",interface,"address", address])


    #print "START UP ETH0"
    #subprocess.call("sudo ip link set dev "+ interface +" up",shell=True)

    subprocess.call(["sudo","ip","link","set","dev",interface,"up"])

    ifChanged = checkIfMACChanged(interface,address)
    
    if ifChanged:
        print "\n[+] The MAC is changed to "+ address + "\n"
    else:
        print "\n[-] Fail to change the MAC address\n"

    if ifShowRes == "1":
        subprocess.call("sudo ip link show",shell=True)



if __name__=='__main__':
    
    interface,address,result = get_arguments()

    changeMAC(interface,address,result)

Based on PYTHON 2.7. Tested on Kali Linux

Usage:
Use -h to see help

python macChanger.py -h  
python macChanger.py -i "eth0" -m 00:11:22:33:44:55 

Reference: "Learn Python & Ethical Hacking From Scratch" by Zaid Sabih. (On Udemy)