Runtime Module pytransform

If you have realized that the obfuscated scripts are black box for end users, you can do more in your own Python scripts.In these cases, pytransform would be useful.

The pytransform module is distributed with obfuscated scripts, and must be imported before running any obfuscated scripts. It also can be used in your python scripts.


exception PytransformError

This is raised when any pytransform api failed. The argument to the exception is a string indicating the cause of the error.


Return how many days left for time limitation license.

>0: valid in these days

-1: never expired


If the obfuscated script has been expired, it will raise exception and quit directly. All the code in the obfuscated script will not run, so this function will not return 0.


Get license information of obfuscated scripts.

It returns a dict with keys expired, CODE, IFMAC.

The value of expired is == -1 means no time limitation.

Raise PytransformError if license is invalid, for example, it has been expired.


Return a string, which is specified as generating the licenses for obfucated scripts.

Raise PytransformError if license is invalid.

get_hd_info(hdtype, size=256)

Get hardware information by hdtype, hdtype could one of

HT_HARDDISK return the serial number of first harddisk

HT_IFMAC return mac address of first network card

Raise PytransformError if something is wrong.


Constant for hdtype when calling get_hd_info()


Copy those example code to any script, for example, obfuscate it, then run the obfuscated script.

Show left days of license

from pytransform import PytransformError, get_license_info, get_expired_days
    code = get_license_info()['CODE']
    left_days = get_expired_days()
    if left_days == -1:
        print('This license for %s is never expired' % code)
        print('This license for %s will be expired in %d days' % (code, left_days))
except PytransformError as e:

Double check harddisk information

from pytransform import get_hd_info, get_license_code, HT_IFMAC
expected_mac_address = get_license_code().split('-')[1]
if get_hd_info(HT_IFMAC) != expected_mac_address:

Then generate one expired license file for this obfuscated script

pyarmor licenses -e 2020-01-01 MAC-70:f1:a1:23:f0:94

Check internet time by NTP server

from ntplib import NTPClient
from time import mktime, strptime
from pytransform import get_license_code

EXPIRED_DATE = get_license_code()[4:]

c = NTPClient()
response = c.request(NTP_SERVER, version=3)
if response.tx_time > mktime(strptime(EXPIRED_DATE, '%Y-%m-%d')):

Also save the expired date in the license file, generate it by this command

pyarmor licenses NTP-2020-01-01


For security, it’s better to move the source of get_license_code and NTPClient into the obfuscated scripts.

Refer to Using Plugin to Extend License Type