def join_2_steps(boundaries, arguments):
    answer = []
    
    for pred_boundaries, pred_arguments in izip(boundaries, arguments):
        cur_arg = ''
        pred_answer = []
        
        for boundary_tag in pred_boundaries:
            if boundary_tag == 'O':
                pred_answer.append('O')
            elif boundary_tag in 'BS':
                cur_arg = pred_arguments.pop(0)
                tag = '%s-%s' % (boundary_tag, cur_arg)
                pred_answer.append(tag)
            else:
                tag = '%s-%s' % (boundary_tag, cur_arg)
                pred_answer.append(tag)
        
        answer.append(pred_answer)
    
    return answer
Joins the tags for argument boundaries and classification accordingly.
dataset/ETHPy150Open erickrf/nlpnet/bin/nlpnet-test.py/join_2_steps