demo_parser.py

import os
from shutil import copyfile

print('---begin of the script---')

demo_path = os.path.join(os.getenv('APPDATA'), "Teeworlds\\demos\\auto")
demo_dest_path = "D:\\Games\\teeworlds\\demos_check"
demos_already_in_dest_path = [file for file in os.listdir(demo_dest_path) if file.endswith(".demo")]

print 'from: ' + demo_path
print 'to: ' + demo_dest_path

demo_files = [file for file in os.listdir(demo_path) if file.endswith(".demo")]

for demo_file in demo_files:
	if demo_file in demos_already_in_dest_path:
		continue
	demo_file_path = os.path.join(demo_path, demo_file)
	with open(demo_file_path, "rb") as f:
		f.seek(178)
		byte = f.read(2).encode("hex")
		markers_num = int('0x' + byte, 0)
		if markers_num > 0:
			print demo_file
			copyfile(demo_file_path, os.path.join(demo_dest_path, demo_file))

print('---end of the script---')