Testing website.

This is H2.

I need to learn MD.

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# basic python packages
import argparse
import glob
import itertools
import json
import logging
import pickle
import random
from argparse import Namespace
from typing import Dict

import numpy as np

logger = logging.getLogger(__name__)

# pytorch lightning packages
import pytorch_lightning as pl

# pytorch packages
import torch
import torch.nn as nn
import torch.nn.functional as F
from pytorch_lightning.callbacks import ModelCheckpoint
from pytorch_lightning.loggers import TensorBoardLogger
from torch.utils.data import DataLoader, IterableDataset

# huggingface transformers packages
from transformers import AdamW, AutoModel, AutoTokenizer
from transformers.optimization import (
    Adafactor,
    get_cosine_schedule_with_warmup,
    get_cosine_with_hard_restarts_schedule_with_warmup,
    get_linear_schedule_with_warmup,
    get_polynomial_decay_schedule_with_warmup,
)

# allennlp dataloading packages
from allennlp.data.dataset_readers.dataset_reader import DatasetReader
from allennlp.data.token_indexers import TokenIndexer
from allennlp.data.tokenizers import Tokenizer
from allennlp.data.tokenizers.token import Token
from allennlp.data.tokenizers.word_splitter import WordSplitter

# Globe constants
training_size = 684100
# validation_size = 145375

# log_every_n_steps how frequently pytorch lightning logs.
# By default, Lightning logs every 50 rows, or 50 training steps.
log_every_n_steps = 1

arg_to_scheduler = {
    "linear": get_linear_schedule_with_warmup,
    "cosine": get_cosine_schedule_with_warmup,
    "cosine_w_restarts": get_cosine_with_hard_restarts_schedule_with_warmup,
    "polynomial": get_polynomial_decay_schedule_with_warmup,
    # '': get_constant_schedule,             # not supported for now
    # '': get_constant_schedule_with_warmup, # not supported for now
}
arg_to_scheduler_choices = sorted(arg_to_scheduler.keys())
arg_to_scheduler_metavar = "{" + ", ".join(arg_to_scheduler_choices) + "}"


class DataReaderFromPickled(DatasetReader):
    """
    This is copied from https://github.com/allenai/specter/blob/673346f9f76bcf422b38e0d1b448ef4414bcd4df/specter/data.py#L61:L109 without any change
    """
    def __init__(self,
                 lazy: bool = False,
                 word_splitter: WordSplitter = None,
                 tokenizer: Tokenizer = None,
                 token_indexers: Dict[str, TokenIndexer] = None,
                 max_sequence_length: int = 256,
                 concat_title_abstract: bool = None
                 ) -> None:
        """
        Dataset reader that uses pickled preprocessed instances
        Consumes the output resulting from data_utils/create_training_files.py

        the additional arguments are not used here and are for compatibility with
        the other data reader at prediction time
        """
        self.max_sequence_length = max_sequence_length
        self.token_indexers = token_indexers
        self._concat_title_abstract = concat_title_abstract
        super().__init__(lazy)

    def _read(self, file_path: str):
        """
        Args:
            file_path: path to the pickled instances
        """
        with open(file_path, 'rb') as f_in:
            unpickler = pickle.Unpickler(f_in)
            while True:
                try:
                    instance = unpickler.load()
                    # compatibility with old models:
                    # for field in instance.fields:
                    #     if hasattr(instance.fields[field], '_token_indexers') and 'bert' in instance.fields[field]._token_indexers:
                    #         if not hasattr(instance.fields['source_title']._token_indexers['bert'], '_truncate_long_sequences'):
                    #             instance.fields[field]._token_indexers['bert']._truncate_long_sequences = True
                    #             instance.fields[field]._token_indexers['bert']._token_min_padding_length = 0
                    if self.max_sequence_length:
                        for paper_type in ['source', 'pos', 'neg']:
                            if self._concat_title_abstract:
                                tokens = []
                                title_field = instance.fields.get(f'{paper_type}_title')
                                abst_field = instance.fields.get(f'{paper_type}_abstract')
                                if title_field:
                                    tokens.extend(title_field.tokens)
                                if tokens:
                                    tokens.extend([Token('[SEP]')])
                                if abst_field:
                                    tokens.extend(abst_field.tokens)
                                if title_field:
                                    title_field.tokens = tokens
                                    instance.fields[f'{paper_type}_title'] = title_field
                                elif abst_field:
                                    abst_field.tokens = tokens
                                    instance.fields[f'{paper_type}_title'] = abst_field
                                else:
                                    yield None
                                # title_tokens = get_text_tokens(query_title_tokens, query_abstract_tokens, abstract_delimiter)
                                # pos_title_tokens = get_text_tokens(pos_title_tokens, pos_abstract_tokens, abstract_delimiter)
                                # neg_title_tokens = get_text_tokens(neg_title_tokens, neg_abstract_tokens, abstract_delimiter)
                                # query_abstract_tokens = pos_abstract_tokens = neg_abstract_tokens = []
                            for field_type in ['title', 'abstract', 'authors', 'author_positions']:
                                field = paper_type + '_' + field_type
                                if instance.fields.get(field):
                                    instance.fields[field].tokens = instance.fields[field].tokens[
                                                                    :self.max_sequence_length]
                                if field_type == 'abstract' and self._concat_title_abstract:
                                    instance.fields.pop(field, None)
                    yield instance
                except EOFError:
                    break


class IterableDataSetMultiWorker(IterableDataset):
    def __init__(self, file_path, tokenizer, size, block_size=100):
        self.datareaderfp = DataReaderFromPickled(max_sequence_length=512)
        self.data_instances = self.datareaderfp._read(file_path)
        self.tokenizer = tokenizer
        self.size = size
        self.block_size = block_size

    def __iter__(self):
        worker_info = torch.utils.data.get_worker_info()
        if worker_info is None:
            iter_end = self.size
            for data_instance in itertools.islice(self.data_instances, iter_end):
                data_input = self.ai2_to_transformers(data_instance, self.tokenizer)
                yield data_input

        else:
            # when num_worker is greater than 1. we implement multiple process data loading.
            iter_end = self.size
            worker_id = worker_info.id
            num_workers = worker_info.num_workers
            i = 0
            for data_instance in itertools.islice(self.data_instances, iter_end):
                if int(i / self.block_size) % num_workers != worker_id:
                    i = i + 1
                    pass
                else:
                    i = i + 1
                    data_input = self.ai2_to_transformers(data_instance, self.tokenizer)
                    yield data_input

    def ai2_to_transformers(self, data_instance, tokenizer):
        """
        Args:
            data_instance: ai2 data instance
            tokenizer: huggingface transformers tokenizer
        """
        source_tokens = data_instance["source_title"].tokens
        source_title = tokenizer(' '.join([str(token) for token in source_tokens]),
                                 truncation=True, padding="max_length", return_tensors="pt",
                                 max_length=512)
        source_input = {'input_ids': source_title['input_ids'][0],
                        'token_type_ids': source_title['token_type_ids'][0],
                        'attention_mask': source_title['attention_mask'][0]}

        pos_tokens = data_instance["pos_title"].tokens
        pos_title = tokenizer(' '.join([str(token) for token in pos_tokens]),
                              truncation=True, padding="max_length", return_tensors="pt", max_length=512)

        pos_input = {'input_ids': pos_title['input_ids'][0],
                     'token_type_ids': pos_title['token_type_ids'][0],
                     'attention_mask': pos_title['attention_mask'][0]}

        neg_tokens = data_instance["neg_title"].tokens
        neg_title = tokenizer(' '.join([str(token) for token in neg_tokens]),
                              truncation=True, padding="max_length", return_tensors="pt", max_length=512)

        neg_input = {'input_ids': neg_title['input_ids'][0],
                     'token_type_ids': neg_title['token_type_ids'][0],
                     'attention_mask': neg_title['attention_mask'][0]}

        return source_input, pos_input, neg_input


class IterableDataSetMultiWorkerTestStep(IterableDataset):
    def __init__(self, file_path, tokenizer, size, block_size=100):
        self.datareaderfp = DataReaderFromPickled(max_sequence_length=512)
        self.data_instances = self.datareaderfp._read(file_path)
        self.tokenizer = tokenizer
        self.size = size
        self.block_size = block_size

    def __iter__(self):
        worker_info = torch.utils.data.get_worker_info()
        if worker_info is None:
            iter_end = self.size
            for data_instance in itertools.islice(self.data_instances, iter_end):
                data_input = self.ai2_to_transformers(data_instance, self.tokenizer)
                yield data_input

        else:
            # when num_worker is greater than 1. we implement multiple process data loading.
            iter_end = self.size
            worker_id = worker_info.id
            num_workers = worker_info.num_workers
            i = 0
            for data_instance in itertools.islice(self.data_instances, iter_end):
                if int(i / self.block_size) % num_workers != worker_id:
                    i = i + 1
                    pass
                else:
                    i = i + 1
                    data_input = self.ai2_to_transformers(data_instance, self.tokenizer)
                    yield data_input

    def ai2_to_transformers(self, data_instance, tokenizer):
        """
        Args:
            data_instance: ai2 data instance
            tokenizer: huggingface transformers tokenizer
        """
        source_tokens = data_instance["source_title"].tokens
        source_title = tokenizer(' '.join([str(token) for token in source_tokens]),
                                 truncation=True, padding="max_length", return_tensors="pt",
                                 max_length=512)
        source_input = {'input_ids': source_title['input_ids'][0],
                        'token_type_ids': source_title['token_type_ids'][0],
                        'attention_mask': source_title['attention_mask'][0]}

        source_paper_id = data_instance['source_paper_id'].metadata

        return source_input, source_paper_id


class TripletLoss(nn.Module):
    """
    Triplet loss: copied from  https://github.com/allenai/specter/blob/673346f9f76bcf422b38e0d1b448ef4414bcd4df/specter/model.py#L159 without any change
    """
    def __init__(self, margin=1.0, distance='l2-norm', reduction='mean'):
        """
        Args:
            margin: margin (float, optional): Default: `1`.
            distance: can be `l2-norm` or `cosine`, or `dot`
            reduction (string, optional): Specifies the reduction to apply to the output:
                'none' | 'mean' | 'sum'. 'none': no reduction will be applied,
                'mean': the sum of the output will be divided by the number of
                elements in the output, 'sum': the output will be summed. Note: :attr:`size_average`
                and :attr:`reduce` are in the process of being deprecated, and in the meantime,
                specifying either of those two args will override :attr:`reduction`. Default: 'mean'
        """
        super(TripletLoss, self).__init__()
        self.margin = margin
        self.distance = distance
        self.reduction = reduction

    def forward(self, query, positive, negative):
        if self.distance == 'l2-norm':
            distance_positive = F.pairwise_distance(query, positive)
            distance_negative = F.pairwise_distance(query, negative)
            losses = F.relu(distance_positive - distance_negative + self.margin)
        elif self.distance == 'cosine':  # independent of length
            distance_positive = F.cosine_similarity(query, positive)
            distance_negative = F.cosine_similarity(query, negative)
            losses = F.relu(-distance_positive + distance_negative + self.margin)
        elif self.distance == 'dot':  # takes into account the length of vectors
            shapes = query.shape
            # batch dot product
            distance_positive = torch.bmm(
                query.view(shapes[0], 1, shapes[1]),
                positive.view(shapes[0], shapes[1], 1)
            ).reshape(shapes[0], )
            distance_negative = torch.bmm(
                query.view(shapes[0], 1, shapes[1]),
                negative.view(shapes[0], shapes[1], 1)
            ).reshape(shapes[0], )
            losses = F.relu(-distance_positive + distance_negative + self.margin)
        else:
            raise TypeError(f"Unrecognized option for `distance`:{self.distance}")

        if self.reduction == 'mean':
            return losses.mean()
        elif self.reduction == 'sum':
            return losses.sum()
        elif self.reduction == 'none':
            return losses
        else:
            raise TypeError(f"Unrecognized option for `reduction`:{self.reduction}")


class Specter(pl.LightningModule):
    def __init__(self, init_args):
        super().__init__()
        if isinstance(init_args, dict):
            # for loading the checkpoint, pl passes a dict (hparams are saved as dict)
            init_args = Namespace(**init_args)
        checkpoint_path = init_args.checkpoint_path
        logger.info(f'loading model from checkpoint: {checkpoint_path}')

        self.hparams = init_args
        self.model = AutoModel.from_pretrained("allenai/scibert_scivocab_cased")
        self.tokenizer = AutoTokenizer.from_pretrained("allenai/scibert_scivocab_cased")
        self.tokenizer.model_max_length = self.model.config.max_position_embeddings
        self.hparams.seqlen = self.model.config.max_position_embeddings
        self.triple_loss = TripletLoss()
        # number of training instances
        self.training_size = None
        # number of testing instances
        self.validation_size = None
        # number of test instances
        self.test_size = None
        # This is a dictionary to save the embeddings for source papers in test step.
        self.embedding_output = {}

    def forward(self, input_ids, token_type_ids, attention_mask):
        # in lightning, forward defines the prediction/inference actions
        source_embedding = self.model(input_ids=input_ids, token_type_ids=token_type_ids, attention_mask=attention_mask)
        return source_embedding[1]

    def _get_loader(self, split):
        if split == 'train':
            fname = self.hparams.train_file
            size = self.training_size
        elif split == 'dev':
            fname = self.hparams.dev_file
            size = self.validation_size
        elif split == 'test':
            fname = self.hparams.test_file
            size = self.test_size
        else:
            assert False

        if split == 'test':
            dataset = IterableDataSetMultiWorkerTestStep(file_path=fname, tokenizer=self.tokenizer, size=size)
        else:
            dataset = IterableDataSetMultiWorker(file_path=fname, tokenizer=self.tokenizer, size=size)

        # pin_memory enables faster data transfer to CUDA-enabled GPU.
        loader = DataLoader(dataset, batch_size=self.hparams.batch_size, num_workers=self.hparams.num_workers,
                            shuffle=False, pin_memory=False)
        return loader

    def setup(self, mode):
        self.train_loader = self._get_loader("train")

    def train_dataloader(self):
        return self.train_loader

    def val_dataloader(self):
        self.val_dataloader_obj = self._get_loader('dev')
        return self.val_dataloader_obj

    def test_dataloader(self):
        return self._get_loader('test')

    @property
    def total_steps(self) -> int:
        """The number of total training steps that will be run. Used for lr scheduler purposes."""
        num_devices = max(1, self.hparams.total_gpus)  # TODO: consider num_tpu_cores
        effective_batch_size = self.hparams.batch_size * self.hparams.grad_accum * num_devices
        # dataset_size = len(self.train_loader.dataset)
        """The size of the training data need to be coded with more accurate number"""
        dataset_size = training_size
        return (dataset_size / effective_batch_size) * self.hparams.num_epochs

    def get_lr_scheduler(self):
        get_schedule_func = arg_to_scheduler[self.hparams.lr_scheduler]
        scheduler = get_schedule_func(
            self.opt, num_warmup_steps=self.hparams.warmup_steps, num_training_steps=self.total_steps
        )
        scheduler = {"scheduler": scheduler, "interval": "step", "frequency": 1}
        return scheduler

    def configure_optimizers(self):
        """Prepare optimizer and schedule (linear warmup and decay)"""
        model = self.model
        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": self.hparams.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,
            },
        ]
        if self.hparams.adafactor:
            optimizer = Adafactor(
                optimizer_grouped_parameters, lr=self.hparams.lr, scale_parameter=False, relative_step=False
            )

        else:
            optimizer = AdamW(
                optimizer_grouped_parameters, lr=self.hparams.lr, eps=self.hparams.adam_epsilon
            )
        self.opt = optimizer

        scheduler = self.get_lr_scheduler()

        return [optimizer], [scheduler]

    def training_step(self, batch, batch_idx):
        source_embedding = self.model(**batch[0])[1]
        pos_embedding = self.model(**batch[1])[1]
        neg_embedding = self.model(**batch[2])[1]

        loss = self.triple_loss(source_embedding, pos_embedding, neg_embedding)

        lr_scheduler = self.trainer.lr_schedulers[0]["scheduler"]

        self.log('train_loss', loss, on_step=True, on_epoch=False, prog_bar=True, logger=True)
        self.log('rate', lr_scheduler.get_last_lr()[-1], on_step=True, on_epoch=False, prog_bar=True, logger=True)
        return {"loss": loss}

    def validation_step(self, batch, batch_idx):
        source_embedding = self.model(**batch[0])[1]
        pos_embedding = self.model(**batch[1])[1]
        neg_embedding = self.model(**batch[2])[1]

        loss = self.triple_loss(source_embedding, pos_embedding, neg_embedding)
        self.log('val_loss', loss, on_step=True, on_epoch=False, prog_bar=True)
        return {'val_loss': loss}

    def _eval_end(self, outputs) -> tuple:
        avg_loss = torch.stack([x['val_loss'] for x in outputs]).mean()
        if self.trainer.use_ddp:
            torch.distributed.all_reduce(avg_loss, op=torch.distributed.ReduceOp.SUM)
            avg_loss /= self.trainer.world_size
        results = {"avg_val_loss": avg_loss}
        for k, v in results.items():
            if isinstance(v, torch.Tensor):
                results[k] = v.detach().cpu().item()
        return results

    def validation_epoch_end(self, outputs: list) -> dict:
        ret = self._eval_end(outputs)

        self.log('avg_val_loss', ret["avg_val_loss"], on_epoch=True, prog_bar=True)

    def test_epoch_end(self, outputs: list):
        # convert the dictionary of {id1:embedding1, id2:embedding2, ...} to a
        # list of dictionaries [{'id':'id1', 'embedding': 'embedding1'},{'id':'id2', 'embedding': 'embedding2'}, ...]
        embedding_output_list = [{'id': key, 'embedding': value.detach().cpu().numpy().tolist()}
                                 for key, value in self.embedding_output.items()]

        with open(self.hparams.save_dir+'/embedding_result.jsonl', 'w') as fp:
            fp.write('\n'.join(json.dumps(i) for i in embedding_output_list))

    def test_step(self, batch, batch_nb):
        source_embedding = self.model(**batch[0])[1]
        source_paper_id = batch[1]

        batch_embedding_output = dict(zip(source_paper_id, source_embedding))

        # .update() will automatically remove duplicates.
        self.embedding_output.update(batch_embedding_output)
        # return self.validation_step(batch, batch_nb)

def parse_args():
    parser = argparse.ArgumentParser()
    parser.add_argument('--checkpoint_path', default=None, help='path to the model (if not setting checkpoint)')
    parser.add_argument('--train_file')
    parser.add_argument('--dev_file')
    parser.add_argument('--test_file')
    parser.add_argument('--input_dir', default=None, help='optionally provide a directory of the data and train/test/dev files will be automatically detected')
    parser.add_argument('--batch_size', default=1, type=int)
    parser.add_argument('--grad_accum', default=1, type=int)
    parser.add_argument('--gpus', default='1')
    parser.add_argument('--seed', default=1918, type=int)
    parser.add_argument('--fp16', default=False, action='store_true')
    parser.add_argument('--test_only', default=False, action='store_true')
    parser.add_argument('--test_checkpoint', default=None)
    parser.add_argument('--limit_test_batches', default=1.0, type=float)
    parser.add_argument('--limit_val_batches', default=1.0, type=float)
    parser.add_argument('--val_check_interval', default=1.0, type=float)
    parser.add_argument('--num_epochs', default=1, type=int)
    parser.add_argument("--lr", type=float, default=2e-5)
    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("--warmup_steps", default=0, type=int, help="Linear warmup over warmup_steps.")
    parser.add_argument("--num_workers", default=4, type=int, help="kwarg passed to DataLoader")
    parser.add_argument("--adafactor", action="store_true")
    parser.add_argument('--save_dir', required=True)

    parser.add_argument('--num_samples', default=None, type=int)
    parser.add_argument("--lr_scheduler",
                        default="linear",
                        choices=arg_to_scheduler_choices,
                        metavar=arg_to_scheduler_metavar,
                        type=str,
                        help="Learning rate scheduler")
    args = parser.parse_args()

    if args.input_dir is not None:
        files = glob.glob(args.input_dir + '/*')
        for f in files:
            fname = f.split('/')[-1]
            if 'train' in fname:
                args.train_file = f
            elif 'dev' in fname or 'val' in fname:
                args.dev_file = f
            elif 'test' in fname:
                args.test_file = f
    return args


def get_train_params(args):
    train_params = {}
    train_params["precision"] = 16 if args.fp16 else 32
    if (isinstance(args.gpus, int) and args.gpus > 1) or (isinstance(args.gpus, list ) and len(args.gpus) > 1):
        train_params["distributed_backend"] = "ddp"
    else:
        train_params["distributed_backend"] = None
    train_params["accumulate_grad_batches"] = args.grad_accum
    train_params['track_grad_norm'] = -1
    train_params['limit_val_batches'] = args.limit_val_batches
    train_params['val_check_interval'] = args.val_check_interval
    train_params['gpus'] = args.gpus
    train_params['max_epochs'] = args.num_epochs
    train_params['log_every_n_steps'] = log_every_n_steps
    return train_params


def main():
    args = parse_args()
    random.seed(args.seed)
    np.random.seed(args.seed)
    torch.manual_seed(args.seed)
    if args.num_workers ==0:
        print("num_workers cannot be less than 1")
        return

    if torch.cuda.is_available():
        torch.cuda.manual_seed_all(args.seed)
    if ',' in args.gpus:
        args.gpus = list(map(int, args.gpus.split(',')))
        args.total_gpus = len(args.gpus)
    else:
        args.gpus = int(args.gpus)
        args.total_gpus = args.gpus

    if args.test_only:
        print('loading model...')
        model = Specter.load_from_checkpoint(args.test_checkpoint)
        trainer = pl.Trainer(gpus=args.gpus, limit_val_batches=args.limit_val_batches)
        trainer.test(model)

    else:

        model = Specter(args)

        # default logger used by trainer
        logger = TensorBoardLogger(
            save_dir=args.save_dir,
            version=0,
            name='pl-logs'
        )

        # second part of the path shouldn't be f-string
        filepath = f'{args.save_dir}/version_{logger.version}/checkpoints/' + 'ep-{epoch}_avg_val_loss-{avg_val_loss:.3f}'
        checkpoint_callback = ModelCheckpoint(
            filepath=filepath,
            save_top_k=1,
            verbose=True,
            monitor='avg_val_loss', # monitors metrics logged by self.log.
            mode='min',
            prefix=''
        )

        extra_train_params = get_train_params(args)

        trainer = pl.Trainer(logger=logger,
                             checkpoint_callback=checkpoint_callback,
                             **extra_train_params)

        trainer.fit(model)


if __name__ == '__main__':
    main()