Check a .rpl file

chkrpl.py

# -*- coding: utf-8 -*-

import argparse
import struct
import os

parser = argparse.ArgumentParser(description='Check .rpl file.')
parser.add_argument('-f', required=True, help='rpl file', dest='file')
args = parser.parse_args()

with open(args.file, 'rb') as f:
  f.seek(0, os.SEEK_END)
  file_len = f.tell()
  f.seek(0, os.SEEK_SET)

  buf = f.read(4)
  buf = struct.unpack('<HH', buf) # little-endian, unsigned short * 2
  i = buf[0] # palette index, maybe
  j = buf[1] # palette index, maybe
  assert 256 > i
  assert 256 > j

  while i < j:
    # r, g, b of palette
    buf = f.read(3)
    buf = struct.unpack('<BBB', buf) # little-endian, unsigned char * 3

    i = i + 1

  assert f.tell() == file_len