def _get_file_rel_path(file_path):
    """Get the lab/Subjects/subject/... part of a file path."""
    file_path = str(file_path).replace('\\', '/')
    # Find the relative part of the file path.
    i = file_path.index('/Subjects')
    if '/' not in file_path[:i]:
        return file_path
    i = file_path[:i].rindex('/') + 1
    return file_path[i:]