def main():
    with open("2017052413_GTS_sn.0017.bin", "rb") as bufrfile:
        data = bufrfile.read()
        delim = b"7777"
        split_bufrs = [b+delim for b in data.split(delim) if b]
        count = 0
        for bufr in split_bufrs:
            with open("2017052413_GTS_sn.0017.bin.{count}".format(count=count), "wb") as out:
                out.write(bufr)
            count += 1

if __name__ == "__main__":
    main()