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import pandas as pd |
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import numpy as np |
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import tensorflow as tf |
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from config import (DISTILBERT_TOKENIZER_N_TOKENS, |
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NEWS_CATEGORY_CLASSIFIER_N_CLASSES, |
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CLASSIFIER_THRESHOLD) |
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from logger import get_logger |
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from find_similar_news import find_similar_news |
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logger = get_logger() |
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from dateutil import parser |
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def correct_date(x): |
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if (not isinstance(x, str)) or (str(x).find(":") == -1): |
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return "2020-11-07 00:36:44+05:30" |
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return x |
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def date_time_parser(dt): |
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""" |
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Computes the minutes elapsed since published time. |
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:param dt: date |
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:return: int, minutes elapsed. |
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""" |
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try: |
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return int(np.round((dt.now(dt.tz) - dt).total_seconds() / 60, 0)) |
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except: |
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return 100000 |
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def delete_outdated_news(final_df: pd.DataFrame): |
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final_df = final_df.copy() |
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final_df["parsed_date"] = final_df["parsed_date"].map(correct_date) |
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final_df["parsed_date"] = final_df["parsed_date"].map(parser.parse) |
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final_df["elapsed_time"] = final_df["parsed_date"].apply(date_time_parser) |
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final_df = final_df.loc[final_df["elapsed_time"] <= 720, :].copy() |
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final_df.drop(columns='elapsed_time', inplace=True) |
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final_df.reset_index(drop=True, inplace=True) |
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return final_df |
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def parse_prediction(tflite_pred, label_encoder): |
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tflite_pred_argmax = np.argmax(tflite_pred, axis=1) |
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tflite_pred_label = label_encoder.inverse_transform(tflite_pred_argmax) |
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tflite_pred_prob = np.max(tflite_pred, axis=1) |
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return tflite_pred_label, tflite_pred_prob |
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def inference(text, interpreter, label_encoder, tokenizer): |
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logger.warning('Entering inference()') |
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batch_size = len(text) |
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logger.warning(f'Samples to predict: {batch_size}') |
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if text != "": |
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tokens = tokenizer(text, max_length=DISTILBERT_TOKENIZER_N_TOKENS, padding="max_length", truncation=True, return_tensors="tf") |
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interpreter.allocate_tensors() |
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input_details = interpreter.get_input_details() |
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output_details = interpreter.get_output_details()[0] |
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attention_mask, input_ids = tokens['attention_mask'], tokens['input_ids'] |
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interpreter.resize_tensor_input(input_details[0]['index'],[batch_size, DISTILBERT_TOKENIZER_N_TOKENS]) |
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interpreter.resize_tensor_input(input_details[1]['index'],[batch_size, DISTILBERT_TOKENIZER_N_TOKENS]) |
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interpreter.resize_tensor_input(output_details['index'],[batch_size, NEWS_CATEGORY_CLASSIFIER_N_CLASSES]) |
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interpreter.allocate_tensors() |
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interpreter.set_tensor(input_details[0]["index"], attention_mask) |
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interpreter.set_tensor(input_details[1]["index"], input_ids) |
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interpreter.invoke() |
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tflite_pred = interpreter.get_tensor(output_details["index"]) |
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tflite_pred = parse_prediction(tflite_pred, label_encoder) |
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logger.warning('Exiting inference()') |
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return tflite_pred |
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def cols_check(new_cols, old_cols): |
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return all([new_col==old_col for new_col, old_col in zip(new_cols, old_cols)]) |
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def predict_news_category_similar_news(old_news: pd.DataFrame, new_news: pd.DataFrame, interpreter, label_encoder, tokenizer, |
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collection, vectorizer, sent_model, ce_model): |
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try: |
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db_updation_required = 1 |
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logger.warning('Entering predict_news_category()') |
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logger.warning(f'old news: {old_news}\nnew_news: {new_news}') |
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if not isinstance(new_news, pd.DataFrame): |
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raise Exception('No New News Found') |
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else: |
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new_news = delete_outdated_news(new_news) |
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logger.warning(f'new news columns: {[*new_news.columns]}') |
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logger.warning(f'{len(new_news)} new news items found') |
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if isinstance(old_news, pd.DataFrame): |
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old_news = delete_outdated_news(old_news) |
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logger.warning(f'old news columns: {[*old_news.columns]}') |
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logger.warning(f'{len(old_news)} old news items found') |
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old_news.drop(columns='_id', inplace=True) |
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logger.warning('Dropped _id column from old news data frame.') |
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else: |
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logger.warning('No old news is found') |
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old_news = new_news.copy() |
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if 'category' not in [*old_news.columns]: |
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logger.warning('No prior predictions found in old news') |
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if not cols_check([*new_news.columns], [*old_news.columns]): |
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raise Exception("New and old cols don't match") |
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final_df = pd.concat([old_news, new_news], axis=0, ignore_index=True) |
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final_df.drop_duplicates(subset='url', keep='first', inplace=True) |
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headlines = [*final_df['title']].copy() |
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label, prob = inference(headlines, interpreter, label_encoder, tokenizer) |
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sent_embs = vectorizer.vectorize_(headlines, sent_model) |
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sim_news = [find_similar_news(text, search_vec, collection, vectorizer, sent_model, ce_model) for search_vec, text in zip(sent_embs, headlines)] |
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final_df['category'] = label |
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final_df['pred_proba'] = prob |
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final_df['similar_news'] = sim_news |
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final_df.reset_index(drop=True, inplace=True) |
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final_df.loc[final_df['pred_proba']<CLASSIFIER_THRESHOLD, 'category'] = 'OTHERS' |
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else: |
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logger.warning('Prior predictions found in old news') |
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if not cols_check([*new_news.columns], [*old_news.columns][:-3]): |
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raise Exception("New and old cols don't match") |
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old_urls = [*old_news['url']] |
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new_news = new_news.loc[new_news['url'].isin(old_urls) == False, :] |
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if len(new_news) > 0: |
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headlines = [*new_news['title']].copy() |
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label, prob = inference(headlines, interpreter, label_encoder, tokenizer) |
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sent_embs = vectorizer.vectorize_(headlines, sent_model) |
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sim_news = [find_similar_news(text, search_vec, collection, vectorizer, sent_model, ce_model) for search_vec, text in zip(sent_embs, headlines)] |
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new_news['category'] = label |
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new_news['pred_proba'] = prob |
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new_news['similar_news'] = sim_news |
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final_df = pd.concat([old_news, new_news], axis=0, ignore_index=True) |
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final_df.drop_duplicates(subset='url', keep='first', inplace=True) |
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final_df.reset_index(drop=True, inplace=True) |
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final_df.loc[final_df['pred_proba']<CLASSIFIER_THRESHOLD, 'category'] = 'OTHERS' |
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else: |
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logger.warning('INFO: Old & New Articles are the same. There is no requirement of updating them in the database. Database is not updated.') |
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db_updation_required = 0 |
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final_df = old_news.copy() |
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if len(final_df) == 0: |
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final_df = None |
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logger.warning('Exiting predict_news_category()') |
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except Exception as e: |
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logger.warning(f'Unexcpected error in predict_news_category()\n{e}') |
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return None |
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return final_df, db_updation_required |
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