def parse_subdir_file(path_to_subdir_file):
    """Parses a .subdir.txt file by splitting its contents into a list by line

    @retval: list with each element containing a line from the .subdir.txt file.
    """
    files = []
    with open(path_to_subdir_file, 'r') as f:
        while True:
            line = f.readline().strip()
            if not line:
                break
            files.append(line)
    return files