text: # coding=utf-8
  # Copyright 2018 The Google AI Language Team Authors and The HuggingFace Inc. team.
  # Copyright (c) 2018, NVIDIA CORPORATION.  All rights reserved.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  """ Finetuning the library models for question-answering on SQuAD (DistilBERT, Bert, XLM, XLNet)."""
  
  
  import argparse
  import glob
  import logging
  import os
  import random
  import timeit
  
  import numpy as np
  import torch
  from torch.utils.data import DataLoader, RandomSampler, SequentialSampler
  from torch.utils.data.distributed import DistributedSampler
  from tqdm import tqdm, trange
  
  from transformers import (
      MODEL_FOR_QUESTION_ANSWERING_MAPPING,
      WEIGHTS_NAME,
      AdamW,
      AutoConfig,
      AutoModelForQuestionAnswering,
      AutoTokenizer,
      get_linear_schedule_with_warmup,
      squad_convert_examples_to_features,
  )
  from transformers.data.metrics.squad_metrics import (
      compute_predictions_log_probs,
      compute_predictions_logits,
      squad_evaluate,
  )
  from transformers.data.processors.squad import SquadResult, SquadV1Processor, SquadV2Processor
  
  
  try:
      from torch.utils.tensorboard import SummaryWriter
  except ImportError:
      from tensorboardX import SummaryWriter
  
  
  logger = logging.getLogger(__name__)
  
  MODEL_CONFIG_CLASSES = list(MODEL_FOR_QUESTION_ANSWERING_MAPPING.keys())
  MODEL_TYPES = tuple(conf.model_type for conf in MODEL_CONFIG_CLASSES)
  
  ALL_MODELS = sum((tuple(conf.pretrained_config_archive_map.keys()) for conf in MODEL_CONFIG_CLASSES), (),)
  
  
  def set_seed(args):
      random.seed(args.seed)
      np.random.seed(args.seed)
      torch.manual_seed(args.seed)
      if args.n_gpu > 0:
          torch.cuda.manual_seed_all(args.seed)
  
  
  def to_list(tensor):
      return tensor.detach().cpu().tolist()
  
  
  def train(args, train_dataset, model, tokenizer):
      """ Train the model """
      if args.local_rank in [-1, 0]:
          tb_writer = SummaryWriter()
  
      args.train_batch_size = args.per_gpu_train_batch_size * max(1, args.n_gpu)
      train_sampler = RandomSampler(train_dataset) if args.local_rank == -1 else DistributedSampler(train_dataset)
      train_dataloader = DataLoader(train_dataset, sampler=train_sampler, batch_size=args.train_batch_size)
  
      if args.max_steps > 0:
          t_total = args.max_steps
          args.num_train_epochs = args.max_steps // (len(train_dataloader) // args.gradient_accumulation_steps) + 1
      else:
          t_total = len(train_dataloader) // args.gradient_accumulation_steps * args.num_train_epochs
  
      # Prepare optimizer and schedule (linear warmup and decay)
      no_decay = ["bias", "LayerNorm.weight"]
      optimizer_grouped_parameters = [
          {
              "params": [p for n, p in model.named_parameters() if not any(nd in n for nd in no_decay)],
              "weight_decay": args.weight_decay,
          },
          {"params": [p for n, p in model.named_parameters() if any(nd in n for nd in no_decay)], "weight_decay": 0.0},
      ]
      optimizer = AdamW(optimizer_grouped_parameters, lr=args.learning_rate, eps=args.adam_epsilon)
      scheduler = get_linear_schedule_with_warmup(
          optimizer, num_warmup_steps=args.warmup_steps, num_training_steps=t_total
      )
  
      # Check if saved optimizer or scheduler states exist
      if os.path.isfile(os.path.join(args.model_name_or_path, "optimizer.pt")) and os.path.isfile(
          os.path.join(args.model_name_or_path, "scheduler.pt")
      ):
          # Load in optimizer and scheduler states
          optimizer.load_state_dict(torch.load(os.path.join(args.model_name_or_path, "optimizer.pt")))
          scheduler.load_state_dict(torch.load(os.path.join(args.model_name_or_path, "scheduler.pt")))
  
      if args.fp16:
          try:
              from apex import amp
          except ImportError:
              raise ImportError("Please install apex from https://www.github.com/nvidia/apex to use fp16 training.")
  
          model, optimizer = amp.initialize(model, optimizer, opt_level=args.fp16_opt_level)
  
      # multi-gpu training (should be after apex fp16 initialization)
      if args.n_gpu > 1:
          model = torch.nn.DataParallel(model)
  
      # Distributed training (should be after apex fp16 initialization)
      if args.local_rank != -1:
          model = torch.nn.parallel.DistributedDataParallel(
              model, device_ids=[args.local_rank], output_device=args.local_rank, find_unused_parameters=True
          )
  
      # Train!
      logger.info("***** Running training *****")
      logger.info("  Num examples = %d", len(train_dataset))
      logger.info("  Num Epochs = %d", args.num_train_epochs)
      logger.info("  Instantaneous batch size per GPU = %d", args.per_gpu_train_batch_size)
      logger.info(
          "  Total train batch size (w. parallel, distributed & accumulation) = %d",
          args.train_batch_size
          * args.gradient_accumulation_steps
          * (torch.distributed.get_world_size() if args.local_rank != -1 else 1),
      )
      logger.info("  Gradient Accumulation steps = %d", args.gradient_accumulation_steps)
      logger.info("  Total optimization steps = %d", t_total)
  
      global_step = 1
      epochs_trained = 0
      steps_trained_in_current_epoch = 0
      # Check if continuing training from a checkpoint
      if os.path.exists(args.model_name_or_path):
          try:
              # set global_step to gobal_step of last saved checkpoint from model path
              checkpoint_suffix = args.model_name_or_path.split("-")[-1].split("/")[0]
              global_step = int(checkpoint_suffix)
              epochs_trained = global_step // (len(train_dataloader) // args.gradient_accumulation_steps)
              steps_trained_in_current_epoch = global_step % (len(train_dataloader) // args.gradient_accumulation_steps)
  
              logger.info("  Continuing training from checkpoint, will skip to saved global_step")
              logger.info("  Continuing training from epoch %d", epochs_trained)
              logger.info("  Continuing training from global step %d", global_step)
              logger.info("  Will skip the first %d steps in the first epoch", steps_trained_in_current_epoch)
          except ValueError:
              logger.info("  Starting fine-tuning.")
  
      tr_loss, logging_loss = 0.0, 0.0
      model.zero_grad()
      train_iterator = trange(
          epochs_trained, int(args.num_train_epochs), desc="Epoch", disable=args.local_rank not in [-1, 0]
      )
      # Added here for reproductibility
      set_seed(args)
  
      for _ in train_iterator:
          epoch_iterator = tqdm(train_dataloader, desc="Iteration", disable=args.local_rank not in [-1, 0])
          for step, batch in enumerate(epoch_iterator):
  
              # Skip past any already trained steps if resuming training
              if steps_trained_in_current_epoch > 0:
                  steps_trained_in_current_epoch -= 1
                  continue
  
              model.train()
              batch = tuple(t.to(args.device) for t in batch)
  
              inputs = {
                  "input_ids": batch[0],
                  "attention_mask": batch[1],
                  "token_type_ids": batch[2],
                  "start_positions": batch[3],
                  "end_positions": batch[4],
              }
  
              if args.model_type in ["xlm", "roberta", "distilbert", "camembert"]:
                  del inputs["token_type_ids"]
  
              if args.model_type in ["xlnet", "xlm"]:
                  inputs.update({"cls_index": batch[5], "p_mask": batch[6]})
                  if args.version_2_with_negative:
                      inputs.update({"is_impossible": batch[7]})
                  if hasattr(model, "config") and hasattr(model.config, "lang2id"):
                      inputs.update(
                          {"langs": (torch.ones(batch[0].shape, dtype=torch.int64) * args.lang_id).to(args.device)}
                      )
  
              outputs = model(**inputs)
              # model outputs are always tuple in transformers (see doc)
              loss = outputs[0]
  
              if args.n_gpu > 1:
                  loss = loss.mean()  # mean() to average on multi-gpu parallel (not distributed) training
              if args.gradient_accumulation_steps > 1:
                  loss = loss / args.gradient_accumulation_steps
  
              if args.fp16:
                  with amp.scale_loss(loss, optimizer) as scaled_loss:
                      scaled_loss.backward()
              else:
                  loss.backward()
  
              tr_loss += loss.item()
              if (step + 1) % args.gradient_accumulation_steps == 0:
                  if args.fp16:
                      torch.nn.utils.clip_grad_norm_(amp.master_params(optimizer), args.max_grad_norm)
                  else:
                      torch.nn.utils.clip_grad_norm_(model.parameters(), args.max_grad_norm)
  
                  optimizer.step()
                  scheduler.step()  # Update learning rate schedule
                  model.zero_grad()
                  global_step += 1
  
                  # Log metrics
                  if args.local_rank in [-1, 0] and args.logging_steps > 0 and global_step % args.logging_steps == 0:
                      # Only evaluate when single GPU otherwise metrics may not average well
                      if args.local_rank == -1 and args.evaluate_during_training:
                          results = evaluate(args, model, tokenizer)
                          for key, value in results.items():
                              tb_writer.add_scalar("eval_{}".format(key), value, global_step)
                      tb_writer.add_scalar("lr", scheduler.get_lr()[0], global_step)
                      print('lr',scheduler.get_lr()[0], global_step)
                      tb_writer.add_scalar("loss", (tr_loss - logging_loss) / args.logging_steps, global_step)
                      print('loss',(tr_loss - logging_loss) / args.logging_steps, global_step)
                      print('-----------------')
                      logging_loss = tr_loss
  
                  # Save model checkpoint
                  if args.local_rank in [-1, 0] and args.save_steps > 0 and global_step % args.save_steps == 0:
                      output_dir = os.path.join(args.output_dir, "checkpoint-{}".format(global_step))
                      if not os.path.exists(output_dir):
                          os.makedirs(output_dir)
                      # Take care of distributed/parallel training
                      model_to_save = model.module if hasattr(model, "module") else model
                      model_to_save.save_pretrained(output_dir)
                      tokenizer.save_pretrained(output_dir)
  
                      torch.save(args, os.path.join(output_dir, "training_args.bin"))
                      logger.info("Saving model checkpoint to %s", output_dir)
  
                      torch.save(optimizer.state_dict(), os.path.join(output_dir, "optimizer.pt"))
                      torch.save(scheduler.state_dict(), os.path.join(output_dir, "scheduler.pt"))
                      logger.info("Saving optimizer and scheduler states to %s", output_dir)
  
              if args.max_steps > 0 and global_step > args.max_steps:
                  epoch_iterator.close()
                  break
          if args.max_steps > 0 and global_step > args.max_steps:
              train_iterator.close()
              break
  
      if args.local_rank in [-1, 0]:
          tb_writer.close()
  
      return global_step, tr_loss / global_step
  
  
  def evaluate(args, model, tokenizer, prefix=""):
      dataset, examples, features = load_and_cache_examples(args, tokenizer, evaluate=True, output_examples=True)
  
      if not os.path.exists(args.output_dir) and args.local_rank in [-1, 0]:
          os.makedirs(args.output_dir)
  
      args.eval_batch_size = args.per_gpu_eval_batch_size * max(1, args.n_gpu)
  
      # Note that DistributedSampler samples randomly
      eval_sampler = SequentialSampler(dataset)
      eval_dataloader = DataLoader(dataset, sampler=eval_sampler, batch_size=args.eval_batch_size)
  
      # multi-gpu evaluate
      if args.n_gpu > 1 and not isinstance(model, torch.nn.DataParallel):
          model = torch.nn.DataParallel(model)
  
      # Eval!
      logger.info("***** Running evaluation {} *****".format(prefix))
      logger.info("  Num examples = %d", len(dataset))
      logger.info("  Batch size = %d", args.eval_batch_size)
  
      all_results = []
      start_time = timeit.default_timer()
  
      for batch in tqdm(eval_dataloader, desc="Evaluating"):
          model.eval()
          batch = tuple(t.to(args.device) for t in batch)
  
          with torch.no_grad():
              inputs = {
                  "input_ids": batch[0],
                  "attention_mask": batch[1],
                  "token_type_ids": batch[2],
              }
  
              if args.model_type in ["xlm", "roberta", "distilbert", "camembert"]:
                  del inputs["token_type_ids"]
  
              feature_indices = batch[3]
  
              # XLNet and XLM use more arguments for their predictions
              if args.model_type in ["xlnet", "xlm"]:
                  inputs.update({"cls_index": batch[4], "p_mask": batch[5]})
                  # for lang_id-sensitive xlm models
                  if hasattr(model, "config") and hasattr(model.config, "lang2id"):
                      inputs.update(
                          {"langs": (torch.ones(batch[0].shape, dtype=torch.int64) * args.lang_id).to(args.device)}
                      )
  
              outputs = model(**inputs)
  
          for i, feature_index in enumerate(feature_indices):
              # TODO: i and feature_index are the same number! Simplify by removing enumerate?
              eval_feature = features[feature_index.item()]
              unique_id = int(eval_feature.unique_id)
  
              output = [to_list(output[i]) for output in outputs]
  
              # Some models (XLNet, XLM) use 5 arguments for their predictions, while the other "simpler"
              # models only use two.
              if len(output) >= 5:
                  start_logits = output[0]
                  start_top_index = output[1]
                  end_logits = output[2]
                  end_top_index = output[3]
                  cls_logits = output[4]
  
                  result = SquadResult(
                      unique_id,
                      start_logits,
                      end_logits,
                      start_top_index=start_top_index,
                      end_top_index=end_top_index,
                      cls_logits=cls_logits,
                  )
  
              else:
                  start_logits, end_logits = output
                  result = SquadResult(unique_id, start_logits, end_logits)
                  # print('-------------')
                  # print('start_logits',result.start_logits)
                  # print('end_logits',result.end_logits)
                  # print('unique_id',result.unique_id)
  
              all_results.append(result)
  
      evalTime = timeit.default_timer() - start_time
      logger.info("  Evaluation done in total %f secs (%f sec per example)", evalTime, evalTime / len(dataset))
  
      # Compute predictions
      output_prediction_file = os.path.join(args.output_dir, "predictions_{}.json".format(prefix))
      output_nbest_file = os.path.join(args.output_dir, "nbest_predictions_{}.json".format(prefix))
  
      if args.version_2_with_negative:
          output_null_log_odds_file = os.path.join(args.output_dir, "null_odds_{}.json".format(prefix))
      else:
          output_null_log_odds_file = None
  
      # XLNet and XLM use a more complex post-processing procedure
      if args.model_type in ["xlnet", "xlm"]:
          start_n_top = model.config.start_n_top if hasattr(model, "config") else model.module.config.start_n_top
          end_n_top = model.config.end_n_top if hasattr(model, "config") else model.module.config.end_n_top
  
          predictions = compute_predictions_log_probs(
              examples,
              features,
              all_results,
              args.n_best_size,
              args.max_answer_length,
              output_prediction_file,
              output_nbest_file,
              output_null_log_odds_file,
              start_n_top,
              end_n_top,
              args.version_2_with_negative,
              tokenizer,
              args.verbose_logging,
          )
      else:
          predictions = compute_predictions_logits(
              examples,
              features,
              all_results,
              args.n_best_size,
              args.max_answer_length,
              args.do_lower_case,
              output_prediction_file,
              output_nbest_file,
              output_null_log_odds_file,
              args.verbose_logging,
              args.version_2_with_negative,
              args.null_score_diff_threshold,
              tokenizer,
          )
  
      # Compute the F1 and exact scores.
      results = squad_evaluate(examples, predictions)
      return results
  
  
  def load_and_cache_examples(args, tokenizer, evaluate=False, output_examples=False):
      if args.local_rank not in [-1, 0] and not evaluate:
          # Make sure only the first process in distributed training process the dataset, and the others will use the cache
          torch.distributed.barrier()
  
      # Load data features from cache or dataset file
      input_dir = args.data_dir if args.data_dir else "."
      cached_features_file = os.path.join(
          input_dir,
          "cached_{}_{}_{}".format(
              "dev" if evaluate else "train",
              list(filter(None, args.model_name_or_path.split("/"))).pop(),
              str(args.max_seq_length),
          ),
      )
  
      # Init features and dataset from cache if it exists
      if os.path.exists(cached_features_file) and not args.overwrite_cache:
          logger.info("Loading features from cached file %s", cached_features_file)
          features_and_dataset = torch.load(cached_features_file)
          features, dataset, examples = (
              features_and_dataset["features"],
              features_and_dataset["dataset"],
              features_and_dataset["examples"],
          )
      else:
          logger.info("Creating features from dataset file at %s", input_dir)
  
          if not args.data_dir and ((evaluate and not args.predict_file) or (not evaluate and not args.train_file)):
              try:
                  import tensorflow_datasets as tfds
              except ImportError:
                  raise ImportError("If not data_dir is specified, tensorflow_datasets needs to be installed.")
  
              if args.version_2_with_negative:
                  logger.warn("tensorflow_datasets does not handle version 2 of SQuAD.")
  
              tfds_examples = tfds.load("squad")
              examples = SquadV1Processor().get_examples_from_dataset(tfds_examples, evaluate=evaluate)
          else:
              processor = SquadV2Processor() if args.version_2_with_negative else SquadV1Processor()
              if evaluate:
                  examples = processor.get_dev_examples(args.data_dir, filename=args.predict_file)
              else:
                  examples = processor.get_train_examples(args.data_dir, filename=args.train_file)
  
          features, dataset = squad_convert_examples_to_features(
              examples=examples,
              tokenizer=tokenizer,
              max_seq_length=args.max_seq_length,
              doc_stride=args.doc_stride,
              max_query_length=args.max_query_length,
              is_training=not evaluate,
              return_dataset="pt",
              threads=args.threads,
          )
  
          if args.local_rank in [-1, 0]:
              logger.info("Saving features into cached file %s", cached_features_file)
              torch.save({"features": features, "dataset": dataset, "examples": examples}, cached_features_file)
  
      if args.local_rank == 0 and not evaluate:
          # Make sure only the first process in distributed training process the dataset, and the others will use the cache
          torch.distributed.barrier()
  
      if output_examples:
          return dataset, examples, features
      return dataset
  
  
  def main():
      parser = argparse.ArgumentParser()
  
      # Required parameters
      parser.add_argument(
          "--model_type",
          default=None,
          type=str,
          required=True,
          help="Model type selected in the list: " + ", ".join(MODEL_TYPES),
      )
      parser.add_argument(
          "--model_name_or_path",
          default=None,
          type=str,
          required=True,
          help="Path to pre-trained model or shortcut name selected in the list: " + ", ".join(ALL_MODELS),
      )
      parser.add_argument(
          "--output_dir",
          default=None,
          type=str,
          required=True,
          help="The output directory where the model checkpoints and predictions will be written.",
      )
  
      # Other parameters
      parser.add_argument(
          "--data_dir",
          default=None,
          type=str,
          help="The input data dir. Should contain the .json files for the task."
          + "If no data dir or train/predict files are specified, will run with tensorflow_datasets.",
      )
      parser.add_argument(
          "--train_file",
          default=None,
          type=str,
          help="The input training file. If a data dir is specified, will look for the file there"
          + "If no data dir or train/predict files are specified, will run with tensorflow_datasets.",
      )
      parser.add_argument(
          "--predict_file",
          default=None,
          type=str,
          help="The input evaluation file. If a data dir is specified, will look for the file there"
          + "If no data dir or train/predict files are specified, will run with tensorflow_datasets.",
      )
      parser.add_argument(
          "--config_name", default="", type=str, help="Pretrained config name or path if not the same as model_name"
      )
      parser.add_argument(
          "--tokenizer_name",
          default="",
          type=str,
          help="Pretrained tokenizer name or path if not the same as model_name",
      )
      parser.add_argument(
          "--cache_dir",
          default="",
          type=str,
          help="Where do you want to store the pre-trained models downloaded from s3",
      )
  
      parser.add_argument(
          "--version_2_with_negative",
          action="store_true",
          help="If true, the SQuAD examples contain some that do not have an answer.",
      )
      parser.add_argument(
          "--null_score_diff_threshold",
          type=float,
          default=0.0,
          help="If null_score - best_non_null is greater than the threshold predict null.",
      )
  
      parser.add_argument(
          "--max_seq_length",
          default=384,
          type=int,
          help="The maximum total input sequence length after WordPiece tokenization. Sequences "
          "longer than this will be truncated, and sequences shorter than this will be padded.",
      )
      parser.add_argument(
          "--doc_stride",
          default=128,
          type=int,
          help="When splitting up a long document into chunks, how much stride to take between chunks.",
      )
      parser.add_argument(
          "--max_query_length",
          default=64,
          type=int,
          help="The maximum number of tokens for the question. Questions longer than this will "
          "be truncated to this length.",
      )
      parser.add_argument("--do_train", action="store_true", help="Whether to run training.")
      parser.add_argument("--do_eval", action="store_true", help="Whether to run eval on the dev set.")
      parser.add_argument(
          "--evaluate_during_training", action="store_true", help="Run evaluation during training at each logging step."
      )
      parser.add_argument(
          "--do_lower_case", action="store_true", help="Set this flag if you are using an uncased model."
      )
  
      parser.add_argument("--per_gpu_train_batch_size", default=8, type=int, help="Batch size per GPU/CPU for training.")
      parser.add_argument(
          "--per_gpu_eval_batch_size", default=8, type=int, help="Batch size per GPU/CPU for evaluation."
      )
      parser.add_argument("--learning_rate", default=5e-5, type=float, help="The initial learning rate for Adam.")
      parser.add_argument(
          "--gradient_accumulation_steps",
          type=int,
          default=1,
          help="Number of updates steps to accumulate before performing a backward/update pass.",
      )
      parser.add_argument("--weight_decay", default=0.0, type=float, help="Weight decay if we apply some.")
      parser.add_argument("--adam_epsilon", default=1e-8, type=float, help="Epsilon for Adam optimizer.")
      parser.add_argument("--max_grad_norm", default=1.0, type=float, help="Max gradient norm.")
      parser.add_argument(
          "--num_train_epochs", default=3.0, type=float, help="Total number of training epochs to perform."
      )
      parser.add_argument(
          "--max_steps",
          default=-1,
          type=int,
          help="If > 0: set total number of training steps to perform. Override num_train_epochs.",
      )
      parser.add_argument("--warmup_steps", default=0, type=int, help="Linear warmup over warmup_steps.")
      parser.add_argument(
          "--n_best_size",
          default=20,
          type=int,
          help="The total number of n-best predictions to generate in the nbest_predictions.json output file.",
      )
      parser.add_argument(
          "--max_answer_length",
          default=30,
          type=int,
          help="The maximum length of an answer that can be generated. This is needed because the start "
          "and end predictions are not conditioned on one another.",
      )
      parser.add_argument(
          "--verbose_logging",
          action="store_true",
          help="If true, all of the warnings related to data processing will be printed. "
          "A number of warnings are expected for a normal SQuAD evaluation.",
      )
      parser.add_argument(
          "--lang_id",
          default=0,
          type=int,
          help="language id of input for language-specific xlm models (see tokenization_xlm.PRETRAINED_INIT_CONFIGURATION)",
      )
  
      parser.add_argument("--logging_steps", type=int, default=500, help="Log every X updates steps.")
      parser.add_argument("--save_steps", type=int, default=500, help="Save checkpoint every X updates steps.")
      parser.add_argument(
          "--eval_all_checkpoints",
          action="store_true",
          help="Evaluate all checkpoints starting with the same prefix as model_name ending and ending with step number",
      )
      parser.add_argument("--no_cuda", action="store_true", help="Whether not to use CUDA when available")
      parser.add_argument(
          "--overwrite_output_dir", action="store_true", help="Overwrite the content of the output directory"
      )
      parser.add_argument(
          "--overwrite_cache", action="store_true", help="Overwrite the cached training and evaluation sets"
      )
      parser.add_argument("--seed", type=int, default=42, help="random seed for initialization")
  
      parser.add_argument("--local_rank", type=int, default=-1, help="local_rank for distributed training on gpus")
      parser.add_argument(
          "--fp16",
          action="store_true",
          help="Whether to use 16-bit (mixed) precision (through NVIDIA apex) instead of 32-bit",
      )
      parser.add_argument(
          "--fp16_opt_level",
          type=str,
          default="O1",
          help="For fp16: Apex AMP optimization level selected in ['O0', 'O1', 'O2', and 'O3']."
          "See details at https://nvidia.github.io/apex/amp.html",
      )
      parser.add_argument("--server_ip", type=str, default="", help="Can be used for distant debugging.")
      parser.add_argument("--server_port", type=str, default="", help="Can be used for distant debugging.")
  
      parser.add_argument("--threads", type=int, default=1, help="multiple threads for converting example to features")
      args = parser.parse_args()
  
      if args.doc_stride >= args.max_seq_length - args.max_query_length:
          logger.warning(
              "WARNING - You've set a doc stride which may be superior to the document length in some "
              "examples. This could result in errors when building features from the examples. Please reduce the doc "
              "stride or increase the maximum length to ensure the features are correctly built."
          )
  
      if (
          os.path.exists(args.output_dir)
          and os.listdir(args.output_dir)
          and args.do_train
          and not args.overwrite_output_dir
      ):
          raise ValueError(
              "Output directory ({}) already exists and is not empty. Use --overwrite_output_dir to overcome.".format(
                  args.output_dir
              )
          )
  
      # Setup distant debugging if needed
      if args.server_ip and args.server_port:
          # Distant debugging - see https://code.visualstudio.com/docs/python/debugging#_attach-to-a-local-script
          import ptvsd
  
          print("Waiting for debugger attach")
          ptvsd.enable_attach(address=(args.server_ip, args.server_port), redirect_output=True)
          ptvsd.wait_for_attach()
  
      # Setup CUDA, GPU & distributed training
      if args.local_rank == -1 or args.no_cuda:
          device = torch.device("cuda" if torch.cuda.is_available() and not args.no_cuda else "cpu")
          args.n_gpu = 0 if args.no_cuda else torch.cuda.device_count()
      else:  # Initializes the distributed backend which will take care of sychronizing nodes/GPUs
          torch.cuda.set_device(args.local_rank)
          device = torch.device("cuda", args.local_rank)
          torch.distributed.init_process_group(backend="nccl")
          args.n_gpu = 1
      args.device = device
  
      # Setup logging
      logging.basicConfig(
          format="%(asctime)s - %(levelname)s - %(name)s -   %(message)s",
          datefmt="%m/%d/%Y %H:%M:%S",
          level=logging.INFO if args.local_rank in [-1, 0] else logging.WARN,
      )
      logger.warning(
          "Process rank: %s, device: %s, n_gpu: %s, distributed training: %s, 16-bits training: %s",
          args.local_rank,
          device,
          args.n_gpu,
          bool(args.local_rank != -1),
          args.fp16,
      )
  
      # Set seed
      set_seed(args)
  
      # Load pretrained model and tokenizer
      if args.local_rank not in [-1, 0]:
          # Make sure only the first process in distributed training will download model & vocab
          torch.distributed.barrier()
  
      args.model_type = args.model_type.lower()
      config = AutoConfig.from_pretrained(
          args.config_name if args.config_name else args.model_name_or_path,
          cache_dir=args.cache_dir if args.cache_dir else None,
      )
      tokenizer = AutoTokenizer.from_pretrained(
          args.tokenizer_name if args.tokenizer_name else args.model_name_or_path,
          do_lower_case=args.do_lower_case,
          cache_dir=args.cache_dir if args.cache_dir else None,
      )
      model = AutoModelForQuestionAnswering.from_pretrained(
          args.model_name_or_path,
          from_tf=bool(".ckpt" in args.model_name_or_path),
          config=config,
          cache_dir=args.cache_dir if args.cache_dir else None,
      )
  
      trainable_layers=['albert.encoder.albert_layer_groups.0.albert_layers.0.ffn_output.weight',
                          'albert.encoder.albert_layer_groups.0.albert_layers.0.ffn_output.bias',
                          'albert.pooler.weight',
                          'albert.pooler.bias',
                          'qa_outputs.weight',
                          'qa_outputs.bias'
                      ]
  
      for name, param in model.named_parameters():
          present_flag=False
          for trainable_layer in trainable_layers:
              if trainable_layer in name:
                  present_flag=True
                  break
          if present_flag==False:
              param.requires_grad = False
          print(name,'-----------')
  
  
      if args.local_rank == 0:
          # Make sure only the first process in distributed training will download model & vocab
          torch.distributed.barrier()
  
      model.to(args.device)
  
      logger.info("Training/evaluation parameters %s", args)
  
      # Before we do anything with models, we want to ensure that we get fp16 execution of torch.einsum if args.fp16 is set.
      # Otherwise it'll default to "promote" mode, and we'll get fp32 operations. Note that running `--fp16_opt_level="O2"` will
      # remove the need for this code, but it is still valid.
      if args.fp16:
          try:
              import apex
  
              apex.amp.register_half_function(torch, "einsum")
          except ImportError:
              raise ImportError("Please install apex from https://www.github.com/nvidia/apex to use fp16 training.")
  
      # Training
      if args.do_train:
          train_dataset = load_and_cache_examples(args, tokenizer, evaluate=False, output_examples=False)
          # exit()
          global_step, tr_loss = train(args, train_dataset, model, tokenizer)
          logger.info(" global_step = %s, average loss = %s", global_step, tr_loss)
  
      # Save the trained model and the tokenizer
      if args.do_train and (args.local_rank == -1 or torch.distributed.get_rank() == 0):
          # Create output directory if needed
          if not os.path.exists(args.output_dir) and args.local_rank in [-1, 0]:
              os.makedirs(args.output_dir)
  
          logger.info("Saving model checkpoint to %s", args.output_dir)
          # Save a trained model, configuration and tokenizer using `save_pretrained()`.
          # They can then be reloaded using `from_pretrained()`
          # Take care of distributed/parallel training
          model_to_save = model.module if hasattr(model, "module") else model
          model_to_save.save_pretrained(args.output_dir)
          tokenizer.save_pretrained(args.output_dir)
  
          # Good practice: save your training arguments together with the trained model
          torch.save(args, os.path.join(args.output_dir, "training_args.bin"))
  
          # Load a trained model and vocabulary that you have fine-tuned
          model = AutoModelForQuestionAnswering.from_pretrained(args.output_dir)  # , force_download=True)
          tokenizer = AutoTokenizer.from_pretrained(args.output_dir, do_lower_case=args.do_lower_case)
          model.to(args.device)
  
      # Evaluation - we can ask to evaluate all the checkpoints (sub-directories) in a directory
      results = {}
  #     if args.do_eval and args.local_rank in [-1, 0]:
  #         if args.do_train:
  #             logger.info("Loading checkpoints saved during training for evaluation")
  #             checkpoints = [args.output_dir]
  #             if args.eval_all_checkpoints:
  #                 checkpoints = list(
  #                     os.path.dirname(c)
  #                     for c in sorted(glob.glob(args.output_dir + "/**/" + WEIGHTS_NAME, recursive=True))
  #                 )
  #                 logging.getLogger("transformers.modeling_utils").setLevel(logging.WARN)  # Reduce model loading logs
  #         else:
  #             logger.info("Loading checkpoint %s for evaluation", args.model_name_or_path)
  #             checkpoints = [args.model_name_or_path]
  
  #         logger.info("Evaluate the following checkpoints: %s", checkpoints)
  
  #         for checkpoint in checkpoints:
  #             # Reload the model
  #             global_step = checkpoint.split("-")[-1] if len(checkpoints) > 1 else ""
  #             model = AutoModelForQuestionAnswering.from_pretrained(checkpoint)  # , force_download=True)
  #             model.to(args.device)
  
  #             # Evaluate
  #             result = evaluate(args, model, tokenizer, prefix=global_step)
  
  #             result = dict((k + ("_{}".format(global_step) if global_step else ""), v) for k, v in result.items())
  #             results.update(result)
  
  #     logger.info("Results: {}".format(results))
  
      return results
  
  
  if __name__ == "__main__":
      main()
  