Backup system for linux with Python

Backup.py

import os
from os import walk
import shutil
from distutils.dir_util import copy_tree

### Backup WIFI Password On Linux ###
files = os.listdir("/etc/NetworkManager/system-connections/")
os.mkdir("Backup")
os.mkdir("Backup/WIFI_PASS")
num = 1
for line in files:
    shutil.copy2("/etc/NetworkManager/system-connections/" + line,
                 "Backup/WIFI_PASS/WIFI-" + str(num) + ".txt")
    num += 1

### Backup Linux Password ###
os.mkdir("Backup/OS_PASS")
os.system("sudo cat /etc/shadow > Backup/OS_PASS/OS_Pass.txt")

### Take Backup ###
os.mkdir("Backup/BackUP")
data_dir = []
for (dirpath, dirnames, filenames) in walk("."):
    data_dir.extend(dirnames)
    break
for dir in data_dir:
    if dir == "Backup":
        pass
    else:
        copy_tree(dir, "Backup/BackUP")
data_file = []
for (dirpath, dirnames, filenames) in walk("."):

    data_file.extend(filenames)
    break
for file in data_file:
    if file == os.path.basename(__file__):
        pass
    else:
        shutil.copy2(file, "Backup/BackUP")