LangChain WIP; demo of RAG integration from Claude Sonnet 3.7

This commit is contained in:
Adam Wilson
2025-05-15 09:30:25 -06:00
parent 8fc43066e0
commit bf145e70b6
4 changed files with 483 additions and 11 deletions
+26 -10
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@@ -8,36 +8,52 @@ from langchain_huggingface import HuggingFaceEmbeddings
from langchain_huggingface import HuggingFacePipeline
from transformers import AutoTokenizer, AutoModelForCausalLM, pipeline
import os
from langchain_community.llms import HuggingFacePipeline
from optimum.onnxruntime import ORTModelForCausalLM
from transformers import AutoTokenizer, pipeline
class Llm:
def __init__(self, model_path=None):
# Get path to the model directory using your specified structure
base_dir = os.path.dirname(os.path.abspath(__file__))
model_path = os.path.join(base_dir, "phi3")
tokenizer = AutoTokenizer.from_pretrained(model_path)
model = AutoModelForCausalLM.from_pretrained(
pretrained_model_name_or_path=model_path,
device_map="cpu", # Use available GPU
trust_remote_code=True, # If model requires custom code
model_path = os.path.join(base_dir, "cpu_and_mobile", "cpu-int4-rtn-block-32-acc-level-4")
# Load the tokenizer from local path
tokenizer = AutoTokenizer.from_pretrained(
model_path,
trust_remote_code=True # Important for some models with custom code
)
# Create a pipeline
# Load the ONNX model with optimum from local path
model = ORTModelForCausalLM.from_pretrained(
model_path,
provider="CPUExecutionProvider",
trust_remote_code=True
)
# Create a text generation pipeline
pipe = pipeline(
"text-generation",
model=model,
tokenizer=tokenizer,
max_new_tokens=512,
temperature=0.7,
top_p=0.9,
repetition_penalty=1.1,
do_sample=True
)
# Create LangChain LLM
self.hf_model = HuggingFacePipeline(pipeline=pipe)
# Create the LangChain LLM
self.llm = HuggingFacePipeline(pipeline=pipe)
def get_response(self, input):
# Use the model
print(f'End user prompt: {input}')
response = self.hf_model.invoke(input)
response = self.llm.invoke(input)
print(response)
if __name__ == "__main__":
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@@ -0,0 +1,263 @@
"""
RAG implementation with local Phi-3-mini-4k-instruct-onnx and embeddings
"""
import os
from typing import List
import numpy as np
# LangChain imports
from langchain_community.llms import HuggingFacePipeline
from langchain_community.embeddings import HuggingFaceEmbeddings
from langchain.text_splitter import RecursiveCharacterTextSplitter
from langchain_community.vectorstores import FAISS
from langchain.chains import RetrievalQA
from langchain.prompts import PromptTemplate
from langchain.schema import Document
# HuggingFace and ONNX imports
from optimum.onnxruntime import ORTModelForCausalLM
from transformers import AutoTokenizer, pipeline
# ------------------------------------------------------
# 1. LOAD THE LOCAL PHI-3 MODEL
# ------------------------------------------------------
# Set up paths to the local model
base_dir = os.path.dirname(os.path.abspath(__file__))
model_path = os.path.join(base_dir, "cpu_and_mobile", "cpu-int4-rtn-block-32-acc-level-4")
print(f"Loading Phi-3 model from: {model_path}")
# Load the tokenizer and model
tokenizer = AutoTokenizer.from_pretrained(model_path, trust_remote_code=True)
model = ORTModelForCausalLM.from_pretrained(
model_path,
provider="CPUExecutionProvider",
trust_remote_code=True
)
# Create the text generation pipeline
pipe = pipeline(
"text-generation",
model=model,
tokenizer=tokenizer,
max_new_tokens=512,
temperature=0.7,
top_p=0.9,
repetition_penalty=1.1,
do_sample=True
)
# Create the LangChain LLM
llm = HuggingFacePipeline(pipeline=pipe)
# ------------------------------------------------------
# 2. LOAD THE EMBEDDING MODEL
# ------------------------------------------------------
# Initialize the embedding model - using a small, efficient model
# Options:
# - "BAAI/bge-small-en-v1.5" (385MB, good performance/size ratio)
# - "sentence-transformers/all-MiniLM-L6-v2" (91MB, very small)
# - "intfloat/e5-small-v2" (134MB, good performance)
embeddings = HuggingFaceEmbeddings(
model_name="sentence-transformers/all-MiniLM-L6-v2",
model_kwargs={"device": "cpu"},
encode_kwargs={"normalize_embeddings": True}
)
print("Embedding model loaded")
# ------------------------------------------------------
# 3. CREATE A SAMPLE DOCUMENT COLLECTION
# ------------------------------------------------------
# Sample documents about artificial intelligence
docs = [
Document(
page_content="Artificial intelligence (AI) is intelligence demonstrated by machines, unlike the natural intelligence displayed by humans and animals, which involves consciousness and emotionality.",
metadata={"source": "AI Definition"}
),
Document(
page_content="Machine learning is a subset of AI focused on building systems that learn from data. Deep learning is a subset of machine learning based on neural networks.",
metadata={"source": "Machine Learning"}
),
Document(
page_content="Neural networks are computing systems inspired by the biological neural networks that constitute animal brains. They form the basis of many modern AI systems.",
metadata={"source": "Neural Networks"}
),
Document(
page_content="Natural Language Processing (NLP) is a field of AI that focuses on the interaction between computers and humans through natural language.",
metadata={"source": "NLP"}
),
Document(
page_content="Reinforcement learning is an area of machine learning where an agent learns to make decisions by taking actions in an environment to maximize a reward signal.",
metadata={"source": "Reinforcement Learning"}
),
Document(
page_content="Computer vision is a field of AI that enables computers to derive meaningful information from digital images, videos and other visual inputs.",
metadata={"source": "Computer Vision"}
),
]
# ------------------------------------------------------
# 4. SPLIT DOCUMENTS AND CREATE VECTOR STORE
# ------------------------------------------------------
# Split documents into chunks
text_splitter = RecursiveCharacterTextSplitter(
chunk_size=500,
chunk_overlap=50,
separators=["\n\n", "\n", ".", " ", ""]
)
# Split the documents
split_docs = text_splitter.split_documents(docs)
print(f"Split {len(docs)} documents into {len(split_docs)} chunks")
# Create a FAISS vector store from the chunks
vectorstore = FAISS.from_documents(split_docs, embeddings)
print("Vector store created")
# ------------------------------------------------------
# 5. CREATE RAG PROMPT TEMPLATE FOR PHI-3
# ------------------------------------------------------
# Phi-3 specific RAG prompt template
rag_prompt_template = """<|user|>
Use the following context to answer the question. If you don't know the answer based on the context, just say you don't know.
Context:
{context}
Question: {question}
<|assistant|>"""
# Create the prompt
prompt = PromptTemplate(
template=rag_prompt_template,
input_variables=["context", "question"]
)
# ------------------------------------------------------
# 6. CREATE RAG CHAIN
# ------------------------------------------------------
# Create the retrieval QA chain
qa_chain = RetrievalQA.from_chain_type(
llm=llm,
chain_type="stuff", # "stuff" method puts all retrieved docs into one prompt
retriever=vectorstore.as_retriever(search_kwargs={"k": 3}), # Retrieve top 3 results
return_source_documents=True, # Return source docs for transparency
chain_type_kwargs={"prompt": prompt} # Use our custom prompt
)
# ------------------------------------------------------
# 7. QUERY FUNCTIONS
# ------------------------------------------------------
def ask_rag(question: str):
"""Query the RAG system with a question"""
print(f"\nQuestion: {question}")
# Get response from the chain
response = qa_chain({"query": question})
# Print the answer
print("\nAnswer:")
print(response["result"])
# Print the source documents
print("\nSources:")
for i, doc in enumerate(response["source_documents"]):
print(f"\nSource {i+1}: {doc.metadata['source']}")
print(f"Content: {doc.page_content}")
return response
# ------------------------------------------------------
# 8. FUNCTION TO LOAD CUSTOM DOCUMENTS
# ------------------------------------------------------
def load_docs_from_files(file_paths: List[str]):
"""Load documents from files"""
from langchain_community.document_loaders import TextLoader, PyPDFLoader
all_docs = []
for file_path in file_paths:
try:
if file_path.lower().endswith('.pdf'):
loader = PyPDFLoader(file_path)
else:
loader = TextLoader(file_path)
docs = loader.load()
all_docs.extend(docs)
print(f"Loaded {len(docs)} document(s) from {file_path}")
except Exception as e:
print(f"Error loading {file_path}: {e}")
return all_docs
def create_rag_from_files(file_paths: List[str]):
"""Create a new RAG system from the provided files"""
# Load documents
loaded_docs = load_docs_from_files(file_paths)
# Split documents
text_splitter = RecursiveCharacterTextSplitter(
chunk_size=500,
chunk_overlap=50,
separators=["\n\n", "\n", ".", " ", ""]
)
split_docs = text_splitter.split_documents(loaded_docs)
# Create vector store
new_vectorstore = FAISS.from_documents(split_docs, embeddings)
# Create QA chain
new_qa_chain = RetrievalQA.from_chain_type(
llm=llm,
chain_type="stuff",
retriever=new_vectorstore.as_retriever(search_kwargs={"k": 3}),
return_source_documents=True,
chain_type_kwargs={"prompt": prompt} # Use our custom prompt
)
return new_qa_chain
# ------------------------------------------------------
# 9. EXAMPLE USAGE
# ------------------------------------------------------
if __name__ == "__main__":
# Test with sample questions
print("\n===== RAG System Demo =====")
# Example 1: Basic retrieval
ask_rag("What is the difference between machine learning and deep learning?")
# Example 2: Testing knowledge boundaries
ask_rag("What are the key components of a neural network?")
# Example 3: Question outside the knowledge base
ask_rag("What is the capital of France?")
print("\n===== Demo Complete =====")
# ------------------------------------------------------
# 10. SAVE AND LOAD VECTOR STORE FOR FUTURE USE
# ------------------------------------------------------
def save_vectorstore(vectorstore, directory="faiss_index"):
"""Save the FAISS vector store to disk"""
vectorstore.save_local(directory)
print(f"Vector store saved to {directory}")
def load_vectorstore(directory="faiss_index"):
"""Load a FAISS vector store from disk"""
if os.path.exists(directory):
loaded_vectorstore = FAISS.load_local(directory, embeddings)
print(f"Vector store loaded from {directory}")
return loaded_vectorstore
else:
print(f"No vector store found at {directory}")
return None