Print information of a quantitative phase imaging dataset

def qpinfo():
    """Print information of a quantitative phase imaging dataset"""
    parser = qpinfo_parser()
    args = parser.parse_args()

    path = pathlib.Path(args.path).resolve()
    try:
        ds = load_data(path)
    except UnknownFileFormatError:
        print("Unknown file format: {}".format(path))
        return

    print("{} ({})".format(ds.__class__.__doc__, ds.__class__.__name__))
    print("- number of images: {}".format(len(ds)))
    for key in ds.meta_data:
        print("- {}: {}".format(key, ds.meta_data[key]))