#!/usr/bin/env python
# -*- coding: utf-8 -*-
import glob
PARAMETRS = ['user_pref("browser.slowStartup.samples", 2);\n',
            'user_pref("browser.startup.homepage", "https://www.google.com/");\n',
            'user_pref("dom.disable_open_during_load", false);\n'
                ]
def config_changer(parametrs):
    """ change firefox preferences file  """
    names = glob.glob("/home/*/.mozilla/firefox/*.default/prefs.js") 
    for name in names:
        with open(name, 'r') as config_read:
            config = config_read.readlines()
            user_name = name.split("/")[2]
            print user_name,
            for line in config:
                for parametr in parametrs:
                    if line.startswith(parametr[:36]):
                        config[config.index(line)] = ""
            for line in config:
                parametrs += line
        with open(name, 'w') as config_save:
            config_save.writelines(parametrs)
if __name__ == "__main__":
    config_changer(PARAMETRS)

python script_name.py

chmod +x

: No such file or directory

./script_name.py

/home/user/script_name.py

!#/usr/bin/python

 sudo: unable to execute /home/user/script_name.py: No such file or directory

cat -vet script.py

^M