TOTP like Google Authenticator

goog_totp.py

import hashlib, hmac, base64, struct, time, math

def GoogleTOTP(s):
    msg = int(math.floor(time.time()/30))
    hm = hmac.new(base64.b32decode(s), struct.pack('>q', msg), hashlib.sha1).digest()
    offs = ord(hm[-1]) & 0xF
    code = str(((struct.unpack('>L',hm[offs:offs+4])[0]) & 0x7FFFFFFF) % 1000000).zfill(6)
    return code

print GoogleTOTP("")