Recall the overall workflow for retrieval augmented generation (RAG):
We discussed Document Loading and Splitting as well as Storage and Retrieval.
We then showed how Retrieval can be used for output generation in Q+A using RetrievalQA chain.
import os
import openai
import sys
sys.path.append('../..')
import panel as pn # GUI
pn.extension()
from dotenv import load_dotenv, find_dotenv
_ = load_dotenv(find_dotenv()) # read local .env file
openai.api_key = os.environ['OPENAI_API_KEY']
The code below was added to assign the openai LLM version filmed until it is deprecated, currently in Sept 2023. LLM responses can often vary, but the responses may be significantly different when using a different model version.
import datetime
current_date = datetime.datetime.now().date()
if current_date < datetime.date(2023, 9, 2):
llm_name = "gpt-3.5-turbo-0301"
else:
llm_name = "gpt-3.5-turbo"
print(llm_name)
If you wish to experiment on LangChain plus platform:
#import os
#os.environ["LANGCHAIN_TRACING_V2"] = "true"
#os.environ["LANGCHAIN_ENDPOINT"] = "https://api.langchain.plus"
#os.environ["LANGCHAIN_API_KEY"] = "..."
from langchain.vectorstores import Chroma
from langchain.embeddings.openai import OpenAIEmbeddings
persist_directory = 'docs/chroma/'
embedding = OpenAIEmbeddings()
vectordb = Chroma(persist_directory=persist_directory, embedding_function=embedding)
question = "What are major topics for this class?"
docs = vectordb.similarity_search(question,k=3)
len(docs)
from langchain.chat_models import ChatOpenAI
llm = ChatOpenAI(model_name=llm_name, temperature=0)
llm.predict("Hello world!")
# Build prompt
from langchain.prompts import PromptTemplate
template = """Use the following pieces of context to answer the question at the end. If you don't know the answer, just say that you don't know, don't try to make up an answer. Use three sentences maximum. Keep the answer as concise as possible. Always say "thanks for asking!" at the end of the answer.
{context}
Question: {question}
Helpful Answer:"""
QA_CHAIN_PROMPT = PromptTemplate(input_variables=["context", "question"],template=template,)
# Run chain
from langchain.chains import RetrievalQA
question = "Is probability a class topic?"
qa_chain = RetrievalQA.from_chain_type(llm,
retriever=vectordb.as_retriever(),
return_source_documents=True,
chain_type_kwargs={"prompt": QA_CHAIN_PROMPT})
result = qa_chain({"query": question})
result["result"]
from langchain.memory import ConversationBufferMemory
memory = ConversationBufferMemory(
memory_key="chat_history",
return_messages=True
)
from langchain.chains import ConversationalRetrievalChain
retriever=vectordb.as_retriever()
qa = ConversationalRetrievalChain.from_llm(
llm,
retriever=retriever,
memory=memory
)
question = "Is probability a class topic?"
result = qa({"question": question})
result['answer']
question = "why are those prerequesites needed?"
result = qa({"question": question})
result['answer']
from langchain.embeddings.openai import OpenAIEmbeddings
from langchain.text_splitter import CharacterTextSplitter, RecursiveCharacterTextSplitter
from langchain.vectorstores import DocArrayInMemorySearch
from langchain.document_loaders import TextLoader
from langchain.chains import RetrievalQA, ConversationalRetrievalChain
from langchain.memory import ConversationBufferMemory
from langchain.chat_models import ChatOpenAI
from langchain.document_loaders import TextLoader
from langchain.document_loaders import PyPDFLoader
The chatbot code has been updated a bit since filming. The GUI appearance also varies depending on the platform it is running on.
def load_db(file, chain_type, k):
# load documents
loader = PyPDFLoader(file)
documents = loader.load()
# split documents
text_splitter = RecursiveCharacterTextSplitter(chunk_size=1000, chunk_overlap=150)
docs = text_splitter.split_documents(documents)
# define embedding
embeddings = OpenAIEmbeddings()
# create vector database from data
db = DocArrayInMemorySearch.from_documents(docs, embeddings)
# define retriever
retriever = db.as_retriever(search_type="similarity", search_kwargs={"k": k})
# create a chatbot chain. Memory is managed externally.
qa = ConversationalRetrievalChain.from_llm(
llm=ChatOpenAI(model_name=llm_name, temperature=0),
chain_type=chain_type,
retriever=retriever,
return_source_documents=True,
return_generated_question=True,
)
return qa
import panel as pn
import param
class cbfs(param.Parameterized):
chat_history = param.List([])
answer = param.String("")
db_query = param.String("")
db_response = param.List([])
def __init__(self, **params):
super(cbfs, self).__init__( **params)
self.panels = []
self.loaded_file = "docs/cs229_lectures/MachineLearning-Lecture01.pdf"
self.qa = load_db(self.loaded_file,"stuff", 4)
def call_load_db(self, count):
if count == 0 or file_input.value is None: # init or no file specified :
return pn.pane.Markdown(f"Loaded File: {self.loaded_file}")
else:
file_input.save("temp.pdf") # local copy
self.loaded_file = file_input.filename
button_load.button_style="outline"
self.qa = load_db("temp.pdf", "stuff", 4)
button_load.button_style="solid"
self.clr_history()
return pn.pane.Markdown(f"Loaded File: {self.loaded_file}")
def convchain(self, query):
if not query:
return pn.WidgetBox(pn.Row('User:', pn.pane.Markdown("", width=600)), scroll=True)
result = self.qa({"question": query, "chat_history": self.chat_history})
self.chat_history.extend([(query, result["answer"])])
self.db_query = result["generated_question"]
self.db_response = result["source_documents"]
self.answer = result['answer']
self.panels.extend([
pn.Row('User:', pn.pane.Markdown(query, width=600)),
pn.Row('ChatBot:', pn.pane.Markdown(self.answer, width=600, style={'background-color': '#F6F6F6'}))
])
inp.value = '' #clears loading indicator when cleared
return pn.WidgetBox(*self.panels,scroll=True)
@param.depends('db_query ', )
def get_lquest(self):
if not self.db_query :
return pn.Column(
pn.Row(pn.pane.Markdown(f"Last question to DB:", styles={'background-color': '#F6F6F6'})),
pn.Row(pn.pane.Str("no DB accesses so far"))
)
return pn.Column(
pn.Row(pn.pane.Markdown(f"DB query:", styles={'background-color': '#F6F6F6'})),
pn.pane.Str(self.db_query )
)
@param.depends('db_response', )
def get_sources(self):
if not self.db_response:
return
rlist=[pn.Row(pn.pane.Markdown(f"Result of DB lookup:", styles={'background-color': '#F6F6F6'}))]
for doc in self.db_response:
rlist.append(pn.Row(pn.pane.Str(doc)))
return pn.WidgetBox(*rlist, width=600, scroll=True)
@param.depends('convchain', 'clr_history')
def get_chats(self):
if not self.chat_history:
return pn.WidgetBox(pn.Row(pn.pane.Str("No History Yet")), width=600, scroll=True)
rlist=[pn.Row(pn.pane.Markdown(f"Current Chat History variable", styles={'background-color': '#F6F6F6'}))]
for exchange in self.chat_history:
rlist.append(pn.Row(pn.pane.Str(exchange)))
return pn.WidgetBox(*rlist, width=600, scroll=True)
def clr_history(self,count=0):
self.chat_history = []
return
cb = cbfs()
file_input = pn.widgets.FileInput(accept='.pdf')
button_load = pn.widgets.Button(name="Load DB", button_type='primary')
button_clearhistory = pn.widgets.Button(name="Clear History", button_type='warning')
button_clearhistory.on_click(cb.clr_history)
inp = pn.widgets.TextInput( placeholder='Enter text hereā¦')
bound_button_load = pn.bind(cb.call_load_db, button_load.param.clicks)
conversation = pn.bind(cb.convchain, inp)
jpg_pane = pn.pane.Image( './img/convchain.jpg')
tab1 = pn.Column(
pn.Row(inp),
pn.layout.Divider(),
pn.panel(conversation, loading_indicator=True, height=300),
pn.layout.Divider(),
)
tab2= pn.Column(
pn.panel(cb.get_lquest),
pn.layout.Divider(),
pn.panel(cb.get_sources ),
)
tab3= pn.Column(
pn.panel(cb.get_chats),
pn.layout.Divider(),
)
tab4=pn.Column(
pn.Row( file_input, button_load, bound_button_load),
pn.Row( button_clearhistory, pn.pane.Markdown("Clears chat history. Can use to start a new topic" )),
pn.layout.Divider(),
pn.Row(jpg_pane.clone(width=400))
)
dashboard = pn.Column(
pn.Row(pn.pane.Markdown('# ChatWithYourData_Bot')),
pn.Tabs(('Conversation', tab1), ('Database', tab2), ('Chat History', tab3),('Configure', tab4))
)
dashboard