Run external python function "run" mostly secure

runner.py

#!/usr/bin/env python3

import os
import sys
import pwd
import grp
from importlib.machinery import SourceFileLoader


def secure(directory, user='nobody', group='nogroup'):

    uid = os.getuid()
    # Not root user, so unable to drop
    if uid != 0:
        return False

    # Get the uid/gid from the name
    current_uid = pwd.getpwnam(user)[2]
    current_gid = grp.getgrnam(group)[2]

    # Change root to another directory
    os.chdir(directory)
    os.chroot(".")

    # New uid and gid
    os.setgid(current_gid)
    os.setuid(current_uid)

    # Change umask
    os.umask(0o077)
    return True


def main(path):

        fullpath = os.path.abspath(path)
        directory = os.path.dirname(fullpath)
        filename = os.path.basename(fullpath)

        if not secure(directory):
            print("unable to secure")
            return False

        try:
            SourceFileLoader("", filename).load_module().run()
        except Exception as e:
            print(e)

        return True


if __name__ == "__main__":
    sys.exit(main(sys.argv[1]))