Backup files to a directory and then encrypts it

backup.py

#!/usr/bin/env python3

import subprocess
import sys 
import logging
from shutil import copytree, ignore_patterns, rmtree
import os
from subprocess import call

logging.basicConfig(
    filename='/var/log/backup.log',
    format='%(asctime)s - %(levelname)s - %(message)s',
    level=logging.INFO
)

logging.info("Started Script")
username = str(subprocess.check_output("whoami").strip().decode('ascii'))
if username != "root":
    logging.critical("You have to be root to run this app, current user is: %s" % (username))
    sys.exit()

if len(sys.argv) > 1:
    password = sys.argv[1]
else:
    print('Please provide password')
    sys.exit()
tmp_backup_folder = "/home/user/tmp_backup"
tmp_out_targz = "/home/user/tmp_backup.tar.gz"
out_gpg = "/home/user/Dropbox/backup.tar.gz.gpg"
systems = {
    "samba": {
        "input": "/etc/samba/",
        "ignore": [
        ]
    },
    "homeassitant": {
        "input": "/home/user/.homeassistant/",
        "ignore": [
            "deps",
            "home-assistant_v2.db",
            "__pycache__",
            "*.pyc",
        ]
    },
}

def  get_size(path):
    size = sum([sum(map(lambda fname: os.path.getsize(os.path.join(directory, fname)), files)) for directory, folders, files in os.walk(path)])
    #2**10 = 1024
    power = 2**10
    n = 0
    Dic_powerN = {0 : '', 1: 'K', 2: 'M', 3: 'G', 4: 'T'}
    while size > power:
        size /=  power
        n += 1
    size = round(size, 2)
    return size, Dic_powerN[n]+'B'


if os.path.isdir(tmp_backup_folder):
    rmtree(tmp_backup_folder)
if os.path.exists(tmp_out_targz):
    os.remove(tmp_out_targz)
if os.path.exists(out_gpg):
    os.remove(out_gpg)
os.makedirs(tmp_backup_folder)

for system, options in systems.items():
    backup_location = os.path.join(tmp_backup_folder, system)
    copytree(options['input'], backup_location, ignore=ignore_patterns(*options['ignore']))
    size, unit = get_size(backup_location)
    logging.info('%s: %s %s' % (system, size, unit))
    print('  %s: %s %s' % (system, size, unit))

size, unit = get_size(tmp_backup_folder)
print('ALL: %s %s' % (size, unit))


a = call("/bin/tar czf %s -C %s ." % (tmp_out_targz, tmp_backup_folder), shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
a = call("/usr/bin/gpg --pinentry-mode loopback --passphrase='%s' -o %s -c %s" % (password, out_gpg, tmp_out_targz), shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)

print('Done with backup')
print('To extract the files do the following:')
print('  gpg --output %s %s' % (tmp_out_targz, out_gpg))
print('  mkdir %s' % (tmp_backup_folder))
print('  tar xfo %s -C %s' % (tmp_out_targz, tmp_backup_folder))
print('  rm -R %s' % (tmp_out_targz))

if os.path.isdir(tmp_backup_folder):
    rmtree(tmp_backup_folder)
if os.path.exists(tmp_out_targz):
    os.remove(tmp_out_targz)