def maximum_prfacc(*evals, eval_metric='accuracy'):
    """Get maximum for multiple evaluations.

    Args:
        evals [tuple]: several evals without limitation
        eval_metric [str]: evaluation standard for comparsion

    Returns:
        max_eval [dict]: one eval with the maximum score
    """
    assert eval_metric in evals[0].keys(), ValueError("Value error of 'eval_metric'.")

    if eval_metric == 'accuracy':
        values = [e[eval_metric] for e in evals]
    else:
        values = [e[eval_metric]['f1-score'] for e in evals]
    index = values.index(max(values))
    max_eval = evals[index]

    return max_eval