Domain Specific BERT Model for Text Mining in Sustainable Investing
Read more about this pre-trained model here.
In collaboration with Charan Pothireddi and Parabole.ai
The further pre-trained ESG-BERT model can be found here at this GitHub repository. It is a PyTorch model but it can be converted into a Tensorflow model. They can be fine-tuned using either framework. I found the PyTorch framework to be a lot cleaner, and easier to replicate with other models. However, serving the final fine-tuned model is a lot easier on TensorFlow, than on PyTorch.
You can download the ESG-BERT model (named pytorch_model.bin) along with config.json and vovab.txt fles here. BERT base model was further pre-trained on Sustainable Investing text corpus, resulting in a domain specific model. You need the all of those 3 files for fine-tuning.
For fine-tuning the model, you can use this command to load it into PyTorch.
model = BertForSequenceClassification.from_pretrained(
'path/to/dir/containing/ESG-BERT',
num_labels = num, #number of classifications
output_attentions = False, # Whether the model returns attentions weights.
output_hidden_states = False, # Whether the model returns all hidden-states.
)
model.to(device)
The fine-tuned model for text classification is also available here. It can be used directly to make predictions using just a few steps. First, download the fine-tuned pytorch_model.bin, config.json, and vocab.txt into your local directory. Make sure to place all of them into the same directory, mine is called "bert_model". JDK 11 is needed to serve the model. Go ahead and install it from the Oracle downloads page. Now we are ready to set up TorcheServe. TorchServe is a model serving architecture for PyTorch models, go ahead and install that using pip. You can also use conda for the installation. We also need pytorch and transformers installed.
pip install torchserve torch-model-archiver
pip install torchvision
pip install transformers
Next up, we'll set up the handler script. It is a basic handler for text classification that can be improved upon. Save this script as "handler.py" in your directory. [1]
from abc import ABC
import json
import logging
import os
import torch
from transformers import AutoModelForSequenceClassification, AutoTokenizer
from ts.torch_handler.base_handler import BaseHandler
logger = logging.getLogger(__name__)
class TransformersClassifierHandler(BaseHandler, ABC):
"""
Transformers text classifier handler class. This handler takes a text (string) and
as input and returns the classification text based on the serialized transformers checkpoint.
"""
def __init__(self):
super(TransformersClassifierHandler, self).__init__()
self.initialized = False
def initialize(self, ctx):
self.manifest = ctx.manifest
properties = ctx.system_properties
model_dir = properties.get("model_dir")
self.device = torch.device("cuda:" + str(properties.get("gpu_id")) if torch.cuda.is_available() else "cpu")
# Read model serialize/pt file
self.model = AutoModelForSequenceClassification.from_pretrained(model_dir)
self.tokenizer = AutoTokenizer.from_pretrained(model_dir)
self.model.to(self.device)
self.model.eval()
logger.debug('Transformer model from path {0} loaded successfully'.format(model_dir))
# Read the mapping file, index to object name
mapping_file_path = os.path.join(model_dir, "index_to_name.json")
if os.path.isfile(mapping_file_path):
with open(mapping_file_path) as f:
self.mapping = json.load(f)
else:
logger.warning('Missing the index_to_name.json file. Inference output will not include class name.')
self.initialized = True
def preprocess(self, data):
""" Very basic preprocessing code - only tokenizes.
Extend with your own preprocessing steps as needed.
"""
text = data[0].get("data")
if text is None:
text = data[0].get("body")
sentences = text.decode('utf-8')
logger.info("Received text: '%s'", sentences)
inputs = self.tokenizer.encode_plus(
sentences,
add_special_tokens=True,
return_tensors="pt"
)
return inputs
def inference(self, inputs):
"""
Predict the class of a text using a trained transformer model.
"""
# NOTE: This makes the assumption that your model expects text to be tokenized
# with "input_ids" and "token_type_ids" - which is true for some popular transformer models, e.g. bert.
# If your transformer model expects different tokenization, adapt this code to suit
# its expected input format.
prediction = self.model(
inputs['input_ids'].to(self.device),
token_type_ids=inputs['token_type_ids'].to(self.device)
)[0].argmax().item()
logger.info("Model predicted: '%s'", prediction)
if self.mapping:
prediction = self.mapping[str(prediction)]
return [prediction]
def postprocess(self, inference_output):
# TODO: Add any needed post-processing of the model predictions here
return inference_output
_service = TransformersClassifierHandler()
def handle(data, context):
try:
if not _service.initialized:
_service.initialize(context)
if data is None:
return None
data = _service.preprocess(data)
data = _service.inference(data)
data = _service.postprocess(data)
return data
except Exception as e:
raise e
TorcheServe uses a format called MAR (Model Archive). We can convert our PyTorch model to a .mar file using this command:
torch-model-archiver --model-name "bert" --version 1.0 --serialized-file ./bert_model/pytorch_model.bin --extra-files "./bert_model/config.json,./bert_model/vocab.txt" --handler "./handler.py"
Move the .mar file into a new directory:
mkdir model_store && mv bert.mar model_store
Finally, we can start TorchServe using the command:
torchserve --start --model-store model_store --models bert=bert.mar
We can now query the model from another terminal window using the Inference API. We pass a text file containing text that the model will try to classify.
curl -X POST http://127.0.0.1:8080/predictions/bert -T predict.txt
This returns a label number which correlates to a textual label. This is stored in the label_dict.txt dictionary file.
__label__Business_Ethics : 0
__label__Data_Security : 1
__label__Access_And_Affordability : 2
__label__Business_Model_Resilience : 3
__label__Competitive_Behavior : 4
__label__Critical_Incident_Risk_Management : 5
__label__Customer_Welfare : 6
__label__Director_Removal : 7
__label__Employee_Engagement_Inclusion_And_Diversity : 8
__label__Employee_Health_And_Safety : 9
__label__Human_Rights_And_Community_Relations : 10
__label__Labor_Practices : 11
__label__Management_Of_Legal_And_Regulatory_Framework : 12
__label__Physical_Impacts_Of_Climate_Change : 13
__label__Product_Quality_And_Safety : 14
__label__Product_Design_And_Lifecycle_Management : 15
__label__Selling_Practices_And_Product_Labeling : 16
__label__Supply_Chain_Management : 17
__label__Systemic_Risk_Management : 18
__label__Waste_And_Hazardous_Materials_Management : 19
__label__Water_And_Wastewater_Management : 20
__label__Air_Quality : 21
__label__Customer_Privacy : 22
__label__Ecological_Impacts : 23
__label__Energy_Management : 24
__label__GHG_Emissions : 25
References: [1] - ---