Замена последовательности символов на другую в бинарных файлах

def is_target(path: str) -> bool:
    extension = path.split('.')[-1].lower()
    if extension in EXTS_TO_IGNORE:
        return False
    elif os.path.islink(path):
        return False
    elif not os.access(path, os.W_OK):
        return False
    elif os.stat(path).st_size == 0:
        return False
    return True


def look_inside(path: str) -> None:
    print(f'{path}: ', end='')
    total = 0
    with open(path, 'r+b') as file:
        with mmap.mmap(file.fileno(), 0) as mm:
            mm: mmap.mmap
            mm.seek(0)
            pos = 0
            while (pos := mm.find(STR_TO_FIND, pos)) >= 0:
                print(f'{pos}', end=' ')
                mm[pos:pos+len(STR_TO_FIND)] = STR_TO_PASTE[0:len(STR_TO_FIND)]
                total += 1
    if total == 0:
        print(f'{STR_TO_FIND} not found.')
    else:
        print(f': {total}')


def find_and_replace(
        root_dir: str,
        saved: str
):
    if os.path.exists(saved):
        with open(saved, 'rb') as pfile:
            processed_files = pickle.load(pfile)
    else:
        processed_files = set()
    total_files_processed = 0
    all_files = 0
    save_every = 100
    for root, dir_names, file_names in os.walk(root_dir, followlinks=False):
        for file_name in file_names:
            all_files += 1
            path_to_file = os.path.join(root, file_name)
            if not is_target(path_to_file):
                continue
            if path_to_file in processed_files:
                print(f'{path_to_file} was processed.')
                continue
            look_inside(path_to_file)
            processed_files.add(path_to_file)
            total_files_processed += 1
            if total_files_processed % save_every == 0:
                with open(saved, 'wb') as pfile:
                    pickle.dump(processed_files, pfile)
    print()
    print(f'Total files found: {all_files}')
    print(f'Total files processed in this session: {total_files_processed}')