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gpt_academic/autogpt/processing/text.py
2023-05-30 15:48:14 +08:00

235 lines
7.9 KiB
Python

"""Text processing functions"""
from math import ceil
from typing import Optional
import spacy
import tiktoken
from autogpt.config import Config
from autogpt.llm.base import ChatSequence
from autogpt.llm.providers.openai import OPEN_AI_MODELS
from autogpt.llm.utils import count_string_tokens, create_chat_completion
from autogpt.logs import logger
from autogpt.utils import batch
CFG = Config()
def _max_chunk_length(model: str, max: Optional[int] = None) -> int:
model_max_input_tokens = OPEN_AI_MODELS[model].max_tokens - 1
if max is not None and max > 0:
return min(max, model_max_input_tokens)
return model_max_input_tokens
def must_chunk_content(
text: str, for_model: str, max_chunk_length: Optional[int] = None
) -> bool:
return count_string_tokens(text, for_model) > _max_chunk_length(
for_model, max_chunk_length
)
def chunk_content(
content: str,
for_model: str,
max_chunk_length: Optional[int] = None,
with_overlap=True,
):
"""Split content into chunks of approximately equal token length."""
MAX_OVERLAP = 200 # limit overlap to save tokens
if not must_chunk_content(content, for_model, max_chunk_length):
yield content, count_string_tokens(content, for_model)
return
max_chunk_length = max_chunk_length or _max_chunk_length(for_model)
tokenizer = tiktoken.encoding_for_model(for_model)
tokenized_text = tokenizer.encode(content)
total_length = len(tokenized_text)
n_chunks = ceil(total_length / max_chunk_length)
chunk_length = ceil(total_length / n_chunks)
overlap = min(max_chunk_length - chunk_length, MAX_OVERLAP) if with_overlap else 0
for token_batch in batch(tokenized_text, chunk_length + overlap, overlap):
yield tokenizer.decode(token_batch), len(token_batch)
def summarize_text(
text: str, instruction: Optional[str] = None, question: Optional[str] = None
) -> tuple[str, None | list[tuple[str, str]]]:
"""Summarize text using the OpenAI API
Args:
text (str): The text to summarize
instruction (str): Additional instruction for summarization, e.g. "focus on information related to polar bears", "omit personal information contained in the text"
Returns:
str: The summary of the text
list[(summary, chunk)]: Text chunks and their summary, if the text was chunked.
None otherwise.
"""
if not text:
raise ValueError("No text to summarize")
if instruction and question:
raise ValueError("Parameters 'question' and 'instructions' cannot both be set")
model = CFG.fast_llm_model
if question:
instruction = (
f'include any information that can be used to answer the question "{question}". '
"Do not directly answer the question itself"
)
summarization_prompt = ChatSequence.for_model(model)
token_length = count_string_tokens(text, model)
logger.info(f"Text length: {token_length} tokens")
# reserve 50 tokens for summary prompt, 500 for the response
max_chunk_length = _max_chunk_length(model) - 550
logger.info(f"Max chunk length: {max_chunk_length} tokens")
if not must_chunk_content(text, model, max_chunk_length):
# summarization_prompt.add("user", text)
summarization_prompt.add(
"user",
"Write a concise summary of the following text"
f"{f'; {instruction}' if instruction is not None else ''}:"
"\n\n\n"
f'LITERAL TEXT: """{text}"""'
"\n\n\n"
"CONCISE SUMMARY: The text is best summarized as"
# "Only respond with a concise summary or description of the user message."
)
logger.debug(f"Summarizing with {model}:\n{summarization_prompt.dump()}\n")
summary = create_chat_completion(
summarization_prompt, temperature=0, max_tokens=500
)
logger.debug(f"\n{'-'*16} SUMMARY {'-'*17}\n{summary}\n{'-'*42}\n")
return summary.strip(), None
summaries: list[str] = []
chunks = list(split_text(text, for_model=model, max_chunk_length=max_chunk_length))
for i, (chunk, chunk_length) in enumerate(chunks):
logger.info(
f"Summarizing chunk {i + 1} / {len(chunks)} of length {chunk_length} tokens"
)
summary, _ = summarize_text(chunk, instruction)
summaries.append(summary)
logger.info(f"Summarized {len(chunks)} chunks")
summary, _ = summarize_text("\n\n".join(summaries))
return summary.strip(), [
(summaries[i], chunks[i][0]) for i in range(0, len(chunks))
]
def split_text(
text: str,
for_model: str = CFG.fast_llm_model,
with_overlap=True,
max_chunk_length: Optional[int] = None,
):
"""Split text into chunks of sentences, with each chunk not exceeding the maximum length
Args:
text (str): The text to split
for_model (str): The model to chunk for; determines tokenizer and constraints
max_length (int, optional): The maximum length of each chunk
Yields:
str: The next chunk of text
Raises:
ValueError: when a sentence is longer than the maximum length
"""
max_length = _max_chunk_length(for_model, max_chunk_length)
# flatten paragraphs to improve performance
text = text.replace("\n", " ")
text_length = count_string_tokens(text, for_model)
if text_length < max_length:
yield text, text_length
return
n_chunks = ceil(text_length / max_length)
target_chunk_length = ceil(text_length / n_chunks)
nlp: spacy.language.Language = spacy.load(CFG.browse_spacy_language_model)
nlp.add_pipe("sentencizer")
doc = nlp(text)
sentences = [sentence.text.strip() for sentence in doc.sents]
current_chunk: list[str] = []
current_chunk_length = 0
last_sentence = None
last_sentence_length = 0
i = 0
while i < len(sentences):
sentence = sentences[i]
sentence_length = count_string_tokens(sentence, for_model)
expected_chunk_length = current_chunk_length + 1 + sentence_length
if (
expected_chunk_length < max_length
# try to create chunks of approximately equal size
and expected_chunk_length - (sentence_length / 2) < target_chunk_length
):
current_chunk.append(sentence)
current_chunk_length = expected_chunk_length
elif sentence_length < max_length:
if last_sentence:
yield " ".join(current_chunk), current_chunk_length
current_chunk = []
current_chunk_length = 0
if with_overlap:
overlap_max_length = max_length - sentence_length - 1
if last_sentence_length < overlap_max_length:
current_chunk += [last_sentence]
current_chunk_length += last_sentence_length + 1
elif overlap_max_length > 5:
# add as much from the end of the last sentence as fits
current_chunk += [
list(
chunk_content(
last_sentence,
for_model,
overlap_max_length,
)
).pop()[0],
]
current_chunk_length += overlap_max_length + 1
current_chunk += [sentence]
current_chunk_length += sentence_length
else: # sentence longer than maximum length -> chop up and try again
sentences[i : i + 1] = [
chunk
for chunk, _ in chunk_content(sentence, for_model, target_chunk_length)
]
continue
i += 1
last_sentence = sentence
last_sentence_length = sentence_length
if current_chunk:
yield " ".join(current_chunk), current_chunk_length