app.py

import streamlit as st
from transformers import DistilBertTokenizer, DistilBertForSequenceClassification
from transformers import Trainer, TrainingArguments
import torch
import json
from sklearn.preprocessing import MultiLabelBinarizer
import numpy as np


@st.cache_resource  
def load_model(model_path):
    model = DistilBertForSequenceClassification.from_pretrained(model_path)
    tokenizer = DistilBertTokenizer.from_pretrained('distilbert-base-cased')

    model.to("cpu") 
    tokenizer = DistilBertTokenizer.from_pretrained('distilbert-base-cased')
    return model, tokenizer


def predict(text, model, tokenizer, threshold=0.5):
    with open("classes.json", "r") as f:
        classes = json.load(f)
    # Tokenize input
    inputs = tokenizer(text, return_tensors="pt", truncation=True, padding=True, max_length=512)
    
    # Move to CPU (if not already)
    inputs = {k: v.to("cpu") for k, v in inputs.items()}
    
    # Predict
    with torch.no_grad():
        outputs = model(**inputs)
    
    # Get logits and apply sigmoid for multi-label classification
    logits = outputs.logits
    probs = np.array(torch.nn.functional.softmax(logits)[0])
    # print(probs)  # Convert to probabilities
    idx = np.argsort(probs)[::-1]
    # print(probs[idx])
    tags = []
    cumsum = 0.0
    ind = 0
    while cumsum <= 0.95:
        tags.append(classes[idx[ind]])
        cumsum += probs[idx[ind]]
        ind += 1

    
    return tags



model, tokenizer = load_model("./results/checkpoint-200")

st.title("Multilabel article classification")
st.header("Based on title and summary")

st.text_input("Input title", key="title")
st.text_input("Input summary", key="summary")

if (st.session_state["title"] or st.session_state["summary"]):
    query = "TITLE:" + st.session_state['title'] + ", SUMMARY:" + st.session_state['summary']
    tags = predict(query, model, tokenizer)

    st.text("Predicted Tags:")
    st.text(", ".join(tags))