def get_weak_csv_filename(data_type):
    """Prepare weakly labelled csv path. 

    Args:
      data_type: 'training' | 'testing' | 'evaluation'

    Returns:
      str, weakly labelled csv path
    """
    if data_type in ['training', 'testing']:
        return '{}_set.csv'.format(data_type)
        
    elif data_type in ['evaluation']:
        return 'groundtruth_weak_label_evaluation_set.csv'
        
    else:
        raise Exception('Incorrect argument!')