文本摘要简述，基于Pytorch和Hugging Face Transformers构建示例，有源码

<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;"><span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">def</span> <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; font-weight: bold; line-height: 26px;">train_loop</span><span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">(dataloader, model, optimizer, lr_scheduler, epoch, total_loss)</span>:</span><br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    progress_bar = tqdm(range(len(dataloader)))<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    progress_bar.set_description(<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">f'loss: <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">{<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">0</span>:><span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">7</span>f}</span>'</span>)<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    finish_batch_num = (epoch<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">-1</span>) * len(dataloader)<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    <br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    model.train()<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">for</span> batch, batch_data <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">in</span> enumerate(dataloader, start=<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">1</span>):<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">        batch_data = batch_data.to(device)<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">        outputs = model(**batch_data)<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">        loss = outputs.loss<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">        optimizer.zero_grad()<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">        loss.backward()<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">        optimizer.step()<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">        lr_scheduler.step()<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;"><br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">        total_loss += loss.item()<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">        <br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">        progress_bar.set_description(<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">f'loss: <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">{total_loss/(finish_batch_num + batch):><span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">7</span>f}</span>'</span>)<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">        progress_bar.update(<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">1</span>)<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    <br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">return</span> total_loss

<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">""" Train the model """</span><br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">total_steps = len(train_dataloader) * num_train_epochs<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;"><span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #75715e; line-height: 26px;"># Prepare optimizer and schedule (linear warmup and decay)</span><br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">no_decay = [<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">"bias"</span>, <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">"LayerNorm.weight"</span>]<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">optimizer_grouped_parameters = [<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    {<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">"params"</span>: [p <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">for</span> n, p <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">in</span> model.named_parameters() <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">if</span> <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">not</span> any(nd <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">in</span> n <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">for</span> nd <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">in</span> no_decay)], <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">"weight_decay"</span>: weight_decay},<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    {<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">"params"</span>: [p <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">for</span> n, p <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">in</span> model.named_parameters() <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">if</span> any(nd <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">in</span> n <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">for</span> nd <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">in</span> no_decay)], <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">"weight_decay"</span>: <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">0.0</span>}<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">]<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">warmup_steps = int(total_steps * warmup_proportion)<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">optimizer = AdamW(<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    optimizer_grouped_parameters, <br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    lr=learning_rate, <br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    betas=(adam_beta1, adam_beta2), <br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    eps=adam_epsilon<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">)<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">lr_scheduler = get_scheduler(<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">'linear'</span>,<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    optimizer, <br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    num_warmup_steps=warmup_steps,<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    num_training_steps=total_steps<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">)<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;"><br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;"><span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #75715e; line-height: 26px;"># Train!</span><br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">logger.info(<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">"***** Running training *****"</span>)<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">logger.info(<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">f"Num examples - <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">{len(train_data)}</span>"</span>)<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">logger.info(<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">f"Num Epochs - <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">{num_train_epochs}</span>"</span>)<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">logger.info(<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">f"Total optimization steps - <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">{total_steps}</span>"</span>)<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;"><br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">total_loss = <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">0.</span><br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">best_avg_rouge = <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">0.</span><br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;"><span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">for</span> epoch <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">in</span> range(num_train_epochs):<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    print(<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">f"Epoch <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">{epoch+<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">1</span>}</span>/<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">{num_train_epochs}</span>n"</span> + <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">30</span> * <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">"-"</span>)<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    total_loss = train_loop(train_dataloader, model, optimizer, lr_scheduler, epoch, total_loss)<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    dev_rouges = test_loop(dev_dataloader, model, tokenizer)<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    logger.info(<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">f"Dev Rouge1: <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">{dev_rouges[<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">'rouge-1'</span>]:><span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">0.2</span>f}</span> Rouge2: <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">{dev_rouges[<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">'rouge-2'</span>]:><span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">0.2</span>f}</span> RougeL: <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">{dev_rouges[<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">'rouge-l'</span>]:><span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">0.2</span>f}</span>"</span>)<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    rouge_avg = dev_rouges[<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">'avg'</span>]<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">    <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #f92672; font-weight: bold; line-height: 26px;">if</span> rouge_avg > best_avg_rouge:<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">        best_avg_rouge = rouge_avg<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">        logger.info(<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">f'saving new weights to <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">{output_dir}</span>...n'</span>)<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">        save_weight = <span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">f'epoch_<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">{epoch+<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">1</span>}</span>_rouge_<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">{rouge_avg:<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; line-height: 26px;">0.4</span>f}</span>_weights.bin'</span><br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">        torch.save(model.state_dict(), os.path.join(output_dir, save_weight))<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">logger.info(<span style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important; color: #a6e22e; line-height: 26px;">"Done!"</span>)<br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;"><br style="margin: 0px; padding: 0px; max-width: 100%; overflow-wrap: break-word !important; box-sizing: border-box !important;">