#!/usr/bin/env python3 -u # Copyright (c) Facebook, Inc. and its affiliates. # # This source code is licensed under the MIT license found in the # LICENSE file in the root directory of this source tree. """ Translate pre-processed data with a trained model. """ import torch from fairseq import bleu, checkpoint_utils, options, progress_bar, tasks, utils from fairseq.meters import StopwatchMeter, TimeMeter def main(args): assert args.path is not None, '--path required for generation!' assert not args.sampling or args.nbest == args.beam, \ '--sampling requires --nbest to be equal to --beam' assert args.replace_unk is None or args.raw_text, \ '--replace-unk requires a raw text dataset (--raw-text)' utils.import_user_module(args) if args.max_tokens is None and args.max_sentences is None: args.max_tokens = 12000 print(args) use_cuda = torch.cuda.is_available() and not args.cpu # Load dataset splits task = tasks.setup_task(args) task.load_dataset(args.gen_subset) # Set dictionaries try: src_dict = getattr(task, 'source_dictionary', None) except NotImplementedError: src_dict = None tgt_dict = task.target_dictionary # Load ensemble print('| loading model(s) from {}'.format(args.path)) models, _model_args = checkpoint_utils.load_model_ensemble( args.path.split(':'), arg_overrides=eval(args.model_overrides), task=task, ) # Optimize ensemble for generation for model in models: model.make_generation_fast_( beamable_mm_beam_size=None if args.no_beamable_mm else args.beam, need_attn=args.print_alignment, ) if args.fp16: model.half() if use_cuda: model.cuda() # Load alignment dictionary for unknown word replacement # (None if no unknown word replacement, empty if no path to align dictionary) align_dict = utils.load_align_dict(args.replace_unk) # Load dataset (possibly sharded) itr = task.get_batch_iterator( dataset=task.dataset(args.gen_subset), max_tokens=args.max_tokens, max_sentences=args.max_sentences, max_positions=utils.resolve_max_positions( task.max_positions(), *[model.max_positions() for model in models] ), ignore_invalid_inputs=args.skip_invalid_size_inputs_valid_test, required_batch_size_multiple=args.required_batch_size_multiple, num_shards=args.num_shards, shard_id=args.shard_id, num_workers=args.num_workers, ).next_epoch_itr(shuffle=False) # Initialize generator gen_timer = StopwatchMeter() generator = task.build_generator(args) # Generate and compute BLEU score if args.sacrebleu: scorer = bleu.SacrebleuScorer() else: scorer = bleu.Scorer(tgt_dict.pad(), tgt_dict.eos(), tgt_dict.unk()) num_sentences = 0 has_target = True with progress_bar.build_progress_bar(args, itr) as t: wps_meter = TimeMeter() for sample in t: sample = utils.move_to_cuda(sample) if use_cuda else sample if 'net_input' not in sample: continue prefix_tokens = None if args.prefix_size > 0: prefix_tokens = sample['target'][:, :args.prefix_size] gen_timer.start() hypos = task.inference_step(generator, models, sample, prefix_tokens) num_generated_tokens = sum(len(h[0]['tokens']) for h in hypos) gen_timer.stop(num_generated_tokens) for i, sample_id in enumerate(sample['id'].tolist()): has_target = sample['target'] is not None # Remove padding src_tokens = utils.strip_pad(sample['net_input']['src_tokens'][i, :], tgt_dict.pad()) target_tokens = None if has_target: target_tokens = utils.strip_pad(sample['target'][i, :], tgt_dict.pad()).int().cpu() # Either retrieve the original sentences or regenerate them from tokens. if align_dict is not None: src_str = task.dataset(args.gen_subset).src.get_original_text(sample_id) target_str = task.dataset(args.gen_subset).tgt.get_original_text(sample_id) else: if src_dict is not None: src_str = src_dict.string(src_tokens, args.remove_bpe) else: src_str = "" if has_target: target_str = tgt_dict.string(target_tokens, args.remove_bpe, escape_unk=True) if not args.quiet: if src_dict is not None: print('S-{}\t{}'.format(sample_id, src_str)) if has_target: print('T-{}\t{}'.format(sample_id, target_str)) # Process top predictions for j, hypo in enumerate(hypos[i][:args.nbest]): hypo_tokens, hypo_str, alignment = utils.post_process_prediction( hypo_tokens=hypo['tokens'].int().cpu(), src_str=src_str, alignment=hypo['alignment'], align_dict=align_dict, tgt_dict=tgt_dict, remove_bpe=args.remove_bpe, ) if not args.quiet: print('H-{}\t{}\t{}'.format(sample_id, hypo['score'], hypo_str)) print('P-{}\t{}'.format( sample_id, ' '.join(map( lambda x: '{:.4f}'.format(x), hypo['positional_scores'].tolist(), )) )) if args.print_alignment: print('A-{}\t{}'.format( sample_id, ' '.join(['{}-{}'.format(src_idx, tgt_idx) for src_idx, tgt_idx in alignment]) )) if args.print_step: print('I-{}\t{}'.format(sample_id, hypo['steps'])) if getattr(args, 'retain_iter_history', False): print("\n".join([ 'E-{}_{}\t{}'.format( sample_id, step, utils.post_process_prediction( h['tokens'].int().cpu(), src_str, None, None, tgt_dict, None)[1]) for step, h in enumerate(hypo['history'])])) # Score only the top hypothesis if has_target and j == 0: if align_dict is not None or args.remove_bpe is not None: # Convert back to tokens for evaluation with unk replacement and/or without BPE target_tokens = tgt_dict.encode_line(target_str, add_if_not_exist=True) if hasattr(scorer, 'add_string'): scorer.add_string(target_str, hypo_str) else: scorer.add(target_tokens, hypo_tokens) wps_meter.update(num_generated_tokens) t.log({'wps': round(wps_meter.avg)}) num_sentences += sample['nsentences'] print('| Translated {} sentences ({} tokens) in {:.1f}s ({:.2f} sentences/s, {:.2f} tokens/s)'.format( num_sentences, gen_timer.n, gen_timer.sum, num_sentences / gen_timer.sum, 1. / gen_timer.avg)) if has_target: print('| Generate {} with beam={}: {}'.format(args.gen_subset, args.beam, scorer.result_string())) return scorer def cli_main(): parser = options.get_generation_parser() args = options.parse_args_and_arch(parser) main(args) if __name__ == '__main__': cli_main()