def _get_file_list(volpath, ext=None, vol_rand_seed=None):
    '\n    get a list of files at the given path with the given extension\n    '
    files = [f for f in sorted(os.listdir(volpath)) if ((ext is None) or f.endswith(ext))]
    if (vol_rand_seed is not None):
        np.random.seed(vol_rand_seed)
        files = np.random.permutation(files).tolist()
    return files
get a list of files at the given path with the given extension
def _get_file_list(volpath, ext=None, vol_rand_seed=None):
    '\n    \n    '
    files = [f for f in sorted(os.listdir(volpath)) if ((ext is None) or f.endswith(ext))]
    if (vol_rand_seed is not None):
        np.random.seed(vol_rand_seed)
        files = np.random.permutation(files).tolist()
    return files