def train_test_validation(closed_data, train_frac=0.8):
    """ 8:1:1 train, text ,validation split """
    train = closed_data.sample(frac=train_frac)
    remain = closed_data.drop(train.index)
    test = remain.sample(frac=0.5)
    validation = remain.drop(test.index)
    return train, test, validation