Automates backups by converting folders to zip archives repeatedly

backup.py

import zipfile
import os, sys
import time, threading

class BackUpLoop(threading.Thread):
	
	def __init__(self, dirName, repeatTime):
		threading.Thread.__init__(self)
		self.dirName = dirName
		self.repeatTime = repeatTime
		self._last_turn = False
		
	def write(zip, root, name):
		zip.write(os.path.join(root, name), compress_type=zipfile.ZIP_DEFLATED)
		
	def run(self):
		while not self._last_turn:
			backup = zipfile.ZipFile(f'{self.dirName}.zip', 'w')
			for root, dirs, files in os.walk(self.dirName + '/'):
				for file in files:
					BackUpLoop.write(backup, root, file)
				for dir in dirs:
					BackUpLoop.write(backup, root, dir)
			backup.close()
			print(f"Successfully backed {self.dirName} up")
			try:
				time.sleep(self.repeatTime)
			except ValueError:
				break
		print("Back up loop successfully stopped")

	def stop_loop(self):
		self._last_turn = True
	
folder = sys.argv[1]
repeatTime = -1
try:
	repeatTime = float(sys.argv[2])
except IndexError:
	pass

loop = BackUpLoop(folder, repeatTime)
loop.start()
print("Backup loop started (press enter to stop)")
input()
print("Stopping program...")
loop.stop_loop()