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reflector/server/utils/text_utils.py
2023-07-26 15:13:46 +07:00

245 lines
8.5 KiB
Python

"""
Utility file for all text processing related functionalities
"""
import nltk
import torch
from nltk.corpus import stopwords
from nltk.tokenize import word_tokenize
from sklearn.feature_extraction.text import TfidfVectorizer
from sklearn.metrics.pairwise import cosine_similarity
from transformers import BartForConditionalGeneration, BartTokenizer
from log_utils import LOGGER
from run_utils import CONFIG
nltk.download('punkt', quiet=True)
def preprocess_sentence(sentence):
stop_words = set(stopwords.words('english'))
tokens = word_tokenize(sentence.lower())
tokens = [token for token in tokens
if token.isalnum() and token not in stop_words]
return ' '.join(tokens)
def compute_similarity(sent1, sent2):
"""
Compute the similarity
"""
tfidf_vectorizer = TfidfVectorizer()
if sent1 is not None and sent2 is not None:
tfidf_matrix = tfidf_vectorizer.fit_transform([sent1, sent2])
return cosine_similarity(tfidf_matrix[0], tfidf_matrix[1])[0][0]
return 0.0
def remove_almost_alike_sentences(sentences, threshold=0.7):
"""
Filter sentences that are similar beyond a set threshold
:param sentences:
:param threshold:
:return:
"""
num_sentences = len(sentences)
removed_indices = set()
for i in range(num_sentences):
if i not in removed_indices:
for j in range(i + 1, num_sentences):
if j not in removed_indices:
l_i = len(sentences[i])
l_j = len(sentences[j])
if l_i == 0 or l_j == 0:
if l_i == 0:
removed_indices.add(i)
if l_j == 0:
removed_indices.add(j)
else:
sentence1 = preprocess_sentence(sentences[i])
sentence2 = preprocess_sentence(sentences[j])
if len(sentence1) != 0 and len(sentence2) != 0:
similarity = compute_similarity(sentence1,
sentence2)
if similarity >= threshold:
removed_indices.add(max(i, j))
filtered_sentences = [sentences[i] for i in range(num_sentences)
if i not in removed_indices]
return filtered_sentences
def remove_outright_duplicate_sentences_from_chunk(chunk):
"""
Remove repetitive sentences
:param chunk:
:return:
"""
chunk_text = chunk["text"]
sentences = nltk.sent_tokenize(chunk_text)
nonduplicate_sentences = list(dict.fromkeys(sentences))
return nonduplicate_sentences
def remove_whisper_repetitive_hallucination(nonduplicate_sentences):
"""
Remove sentences that are repeated as a result of Whisper
hallucinations
:param nonduplicate_sentences:
:return:
"""
chunk_sentences = []
for sent in nonduplicate_sentences:
temp_result = ""
seen = {}
words = nltk.word_tokenize(sent)
n_gram_filter = 3
for i in range(len(words)):
if str(words[i:i + n_gram_filter]) in seen and \
seen[str(words[i:i + n_gram_filter])] == \
words[i + 1:i + n_gram_filter + 2]:
pass
else:
seen[str(words[i:i + n_gram_filter])] = \
words[i + 1:i + n_gram_filter + 2]
temp_result += words[i]
temp_result += " "
chunk_sentences.append(temp_result)
return chunk_sentences
def post_process_transcription(whisper_result):
"""
Parent function to perform post-processing on the transcription result
:param whisper_result:
:return:
"""
transcript_text = ""
for chunk in whisper_result["chunks"]:
nonduplicate_sentences = \
remove_outright_duplicate_sentences_from_chunk(chunk)
chunk_sentences = \
remove_whisper_repetitive_hallucination(nonduplicate_sentences)
similarity_matched_sentences = \
remove_almost_alike_sentences(chunk_sentences)
chunk["text"] = " ".join(similarity_matched_sentences)
transcript_text += chunk["text"]
whisper_result["text"] = transcript_text
return whisper_result
def summarize_chunks(chunks, tokenizer, model):
"""
Summarize each chunk using a summarizer model
:param chunks:
:param tokenizer:
:param model:
:return:
"""
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
summaries = []
for c in chunks:
input_ids = tokenizer.encode(c, return_tensors='pt')
input_ids = input_ids.to(device)
with torch.no_grad():
summary_ids = \
model.generate(input_ids,
num_beams=int(CONFIG["SUMMARIZER"]["BEAM_SIZE"]),
length_penalty=2.0,
max_length=int(CONFIG["SUMMARIZER"]["MAX_LENGTH"]),
early_stopping=True)
summary = tokenizer.decode(summary_ids[0],
skip_special_tokens=True)
summaries.append(summary)
return summaries
def chunk_text(text,
max_chunk_length=int(CONFIG["SUMMARIZER"]["MAX_CHUNK_LENGTH"])):
"""
Split text into smaller chunks.
:param text: Text to be chunked
:param max_chunk_length: length of chunk
:return: chunked texts
"""
sentences = nltk.sent_tokenize(text)
chunks = []
current_chunk = ""
for sentence in sentences:
if len(current_chunk) + len(sentence) < max_chunk_length:
current_chunk += f" {sentence.strip()}"
else:
chunks.append(current_chunk.strip())
current_chunk = f"{sentence.strip()}"
chunks.append(current_chunk.strip())
return chunks
def summarize(transcript_text, timestamp,
real_time=False,
chunk_summarize=CONFIG["SUMMARIZER"]["SUMMARIZE_USING_CHUNKS"]):
"""
Summarize the given text either as a whole or as chunks as needed
:param transcript_text:
:param timestamp:
:param real_time:
:param chunk_summarize:
:return:
"""
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
summary_model = CONFIG["SUMMARIZER"]["SUMMARY_MODEL"]
if not summary_model:
summary_model = "facebook/bart-large-cnn"
# Summarize the generated transcript using the BART model
LOGGER.info(f"Loading BART model: {summary_model}")
tokenizer = BartTokenizer.from_pretrained(summary_model)
model = BartForConditionalGeneration.from_pretrained(summary_model)
model = model.to(device)
output_file = "summary_" + timestamp.strftime("%m-%d-%Y_%H:%M:%S") + ".txt"
if real_time:
output_file = "real_time_" + output_file
if chunk_summarize != "YES":
max_length = int(CONFIG["SUMMARIZER"]["INPUT_ENCODING_MAX_LENGTH"])
inputs = tokenizer. \
batch_encode_plus([transcript_text], truncation=True,
padding='longest',
max_length=max_length,
return_tensors='pt')
inputs = inputs.to(device)
with torch.no_grad():
num_beans = int(CONFIG["SUMMARIZER"]["BEAM_SIZE"])
max_length = int(CONFIG["SUMMARIZER"]["MAX_LENGTH"])
summaries = model.generate(inputs['input_ids'],
num_beams=num_beans,
length_penalty=2.0,
max_length=max_length,
early_stopping=True)
decoded_summaries = \
[tokenizer.decode(summary,
skip_special_tokens=True,
clean_up_tokenization_spaces=False)
for summary in summaries]
summary = " ".join(decoded_summaries)
with open("./artefacts/" + output_file, 'w', encoding="utf-8") as file:
file.write(summary.strip() + "\n")
else:
LOGGER.info("Breaking transcript into smaller chunks")
chunks = chunk_text(transcript_text)
LOGGER.info(f"Transcript broken into {len(chunks)} "
f"chunks of at most 500 words")
LOGGER.info(f"Writing summary text to: {output_file}")
with open(output_file, 'w') as f:
summaries = summarize_chunks(chunks, tokenizer, model)
for summary in summaries:
f.write(summary.strip() + " ")