Files
reflector/server/utils/text_utils.py
2023-07-27 14:08:41 +02:00

265 lines
8.6 KiB
Python

"""
Utility file for all text processing related functionalities
"""
import datetime
from typing import List
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: str) -> str:
"""
Filter out undesirable tokens from thr sentence
:param sentence:
:return:
"""
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: str, sent2: str) -> float:
"""
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: List[str], threshold=0.7) -> List[str]:
"""
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: str) -> List[str]:
"""
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: List[str],
) -> List[str]:
"""
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: dict) -> dict:
"""
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: List[str], tokenizer, model) -> List[str]:
"""
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: str, max_chunk_length: int = int(CONFIG["SUMMARIZER"]["MAX_CHUNK_LENGTH"])
) -> List[str]:
"""
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: str,
timestamp: datetime.datetime.timestamp,
real_time: bool = False,
chunk_summarize: str = 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() + " ")