Add changes per PR Fix broken ingest and start langchain-ai#94

Author: Barry Weiss

ingest.py

@@ -9,7 +9,7 @@
 
 def ingest_docs():
     """Get documents from web pages."""
-    loader = ReadTheDocsLoader("langchain.readthedocs.io/en/latest/")
+    loader = ReadTheDocsLoader("langchain.readthedocs.io/en/latest/", features="lxml")
     raw_documents = loader.load()
     text_splitter = RecursiveCharacterTextSplitter(
         chunk_size=1000,

query_data.py

@@ -2,9 +2,9 @@
 import os
 from dotenv import load_dotenv
 
-from langchain.callbacks.base import AsyncCallbackManager
+from langchain.callbacks.manager import AsyncCallbackManager
 from langchain.callbacks.tracers import LangChainTracer
-from langchain.chains import ChatVectorDBChain
+from langchain.chains import ConversationalRetrievalChain
 from langchain.chains.chat_vector_db.prompts import (CONDENSE_QUESTION_PROMPT,
                                                      QA_PROMPT)
 from langchain.chains.llm import LLMChain
@@ -20,9 +20,9 @@
 
 def get_chain(
     vectorstore: VectorStore, question_handler, stream_handler, tracing: bool = False
-) -> ChatVectorDBChain:
-    """Create a ChatVectorDBChain for question/answering."""
-    # Construct a ChatVectorDBChain with a streaming llm for combine docs
+) -> ConversationalRetrievalChain:
+    """Create a ConversationalRetrievalChain for question/answering."""
+    # Construct a ConversationalRetrievalChain with a streaming llm for combine docs
     # and a separate, non-streaming llm for question generation
     manager = AsyncCallbackManager([])
     question_manager = AsyncCallbackManager([question_handler])
@@ -53,8 +53,8 @@ def get_chain(
         streaming_llm, chain_type="stuff", prompt=QA_PROMPT, callback_manager=manager
     )
 
-    qa = ChatVectorDBChain(
-        vectorstore=vectorstore,
+    qa = ConversationalRetrievalChain(
+        retriever=vectorstore.as_retriever(),
         combine_docs_chain=doc_chain,
         question_generator=question_generator,
         callback_manager=manager,