Scrapegraph-ai/scrapegraphai/nodes/rag_node.py
2024-04-11 19:26:38 +02:00

127 lines
4.8 KiB
Python

"""
Module for parsing the HTML node
"""
from typing import List
from langchain.docstore.document import Document
from langchain.retrievers import ContextualCompressionRetriever
from langchain.retrievers.document_compressors import EmbeddingsFilter, DocumentCompressorPipeline
from langchain_community.document_transformers import EmbeddingsRedundantFilter
from langchain_community.embeddings import HuggingFaceHubEmbeddings
from langchain_community.vectorstores import FAISS
from langchain_openai import OpenAIEmbeddings, AzureOpenAIEmbeddings
from ..models import OpenAI, Ollama, AzureOpenAI, HuggingFace
from langchain_community.embeddings import OllamaEmbeddings
from .base_node import BaseNode
class RAGNode(BaseNode):
"""
A node responsible for compressing the input tokens and storing the document
in a vector database for retrieval.
It allows scraping of big documents without exceeding the token limit of the language model.
Attributes:
node_name (str): The unique identifier name for the node, defaulting to "ParseHTMLNode".
node_type (str): The type of the node, set to "node" indicating a standard operational node.
Args:
node_name (str, optional): The unique identifier name for the node.
Defaults to "ParseHTMLNode".
Methods:
execute(state): Parses the HTML document contained within the state using
the specified tags, if provided, and updates the state with the parsed content.
"""
def __init__(self, input: str, output: List[str], node_config: dict, node_name: str = "RAG"):
"""
Initializes the ParseHTMLNode with a node name.
"""
super().__init__(node_name, "node", input, output, 2, node_config)
self.llm_model = node_config["llm"]
self.embedder_model = node_config.get("embedder_model", None)
def execute(self, state):
"""
Executes the node's logic to implement RAG (Retrieval-Augmented Generation)
The method updates the state with relevant chunks of the document.
Args:
state (dict): The state containing the 'document' key with the HTML content
Returns:
dict: The updated state containing the 'relevant_chunks' key with the relevant chunks.
Raises:
KeyError: If 'document' is not found in the state, indicating that the necessary
information for parsing is missing.
"""
print(f"--- Executing {self.node_name} Node ---")
# Interpret input keys based on the provided input expression
input_keys = self.get_input_keys(state)
# Fetching data from the state based on the input keys
input_data = [state[key] for key in input_keys]
user_prompt = input_data[0]
doc = input_data[1]
chunked_docs = []
for i, chunk in enumerate(doc):
doc = Document(
page_content=chunk,
metadata={
"chunk": i + 1,
},
)
chunked_docs.append(doc)
print("--- (updated chunks metadata) ---")
# check if embedder_model is provided, if not use llm_model
embedding_model = self.embedder_model if self.embedder_model else self.llm_model
if isinstance(embedding_model, OpenAI):
embeddings = OpenAIEmbeddings(
api_key=embedding_model.openai_api_key)
elif isinstance(embedding_model, AzureOpenAI):
embeddings = AzureOpenAIEmbeddings()
elif isinstance(embedding_model, Ollama):
embeddings = OllamaEmbeddings(model=embedding_model.model)
elif isinstance(embedding_model, HuggingFace):
embeddings = HuggingFaceHubEmbeddings(model=embedding_model.model)
else:
raise ValueError("Embedding Model missing or not supported")
retriever = FAISS.from_documents(
chunked_docs, embeddings).as_retriever()
redundant_filter = EmbeddingsRedundantFilter(embeddings=embeddings)
# similarity_threshold could be set, now k=20
relevant_filter = EmbeddingsFilter(embeddings=embeddings)
pipeline_compressor = DocumentCompressorPipeline(
transformers=[redundant_filter, relevant_filter]
)
# redundant + relevant filter compressor
compression_retriever = ContextualCompressionRetriever(
base_compressor=pipeline_compressor, base_retriever=retriever
)
# relevant filter compressor only
# compression_retriever = ContextualCompressionRetriever(
# base_compressor=relevant_filter, base_retriever=retriever
# )
compressed_docs = compression_retriever.get_relevant_documents(
user_prompt)
print("--- (tokens compressed and vector stored) ---")
state.update({self.output[0]: compressed_docs})
return state