code: def read_bytes(self):
  		
  		global exit_flag
  
  		for self.i in range(0, self.length) :
  			self.bytes[self.i] = i_max[self.i]
  			self.maxbytes[self.i] = total_chunks[self.i]
  			self.progress[self.i]["maximum"] = total_chunks[self.i]
  			self.progress[self.i]["value"] = self.bytes[self.i]
  			self.str[self.i].set(file_name[self.i]+ "       " + str(self.bytes[self.i]) 
  								  + "KB / " + str(int(self.maxbytes[self.i] + 1)) + " KB")
  
  		if exit_flag == self.length:
  			exit_flag = 0
  			self.frame.destroy()
  		else:
  			self.frame.after(10, self.read_bytes)
docs: reading bytes; update progress bar after 1 ms