def get_prompt_files(prompt_pool_path, train_clusters: str):
    """
    train_clusters: a string representing all clusters concatenated by `+`,
    e.g.,
    `nli+close_qa` denotes nli and close_qa clusters
    """
    clusters=train_clusters.split('+')
    prompt_pool_dirs = [
        f"{prompt_pool_path}/{cluster}/*"
        for cluster in clusters
    ]
    logger.info("prompt pool dirs: %s", prompt_pool_dirs)
    prompt_pool_paths = []
    for dir in prompt_pool_dirs:
        prompt_pool_paths.extend(glob.glob(dir))
    return prompt_pool_paths

    train_clusters: a string representing all clusters concatenated by `+`,
    e.g.,
    `nli+close_qa` denotes nli and close_qa clusters
    
se2/DPR/dpr/utils/tasks.py