o Jjg @sNddlmZddlmZmZmZddlmZmZddl m Z m Z dd d Z d S)) annotations)AnyDictUnion) BaseRetrieverRetrieverOutput)RunnableRunnablePassthrough retriever5Union[BaseRetriever, Runnable[dict, RetrieverOutput]]combine_docs_chainRunnable[Dict[str, Any], str]returnrcCsDt|ts|}ndd|B}tj|jdddj|djdd}|S)afCreate retrieval chain that retrieves documents and then passes them on. Args: retriever: Retriever-like object that returns list of documents. Should either be a subclass of BaseRetriever or a Runnable that returns a list of documents. If a subclass of BaseRetriever, then it is expected that an `input` key be passed in - this is what is will be used to pass into the retriever. If this is NOT a subclass of BaseRetriever, then all the inputs will be passed into this runnable, meaning that runnable should take a dictionary as input. combine_docs_chain: Runnable that takes inputs and produces a string output. The inputs to this will be any original inputs to this chain, a new context key with the retrieved documents, and chat_history (if not present in the inputs) with a value of `[]` (to easily enable conversational retrieval. Returns: An LCEL Runnable. The Runnable return is a dictionary containing at the very least a `context` and `answer` key. Example: .. code-block:: python # pip install -U langchain langchain-community from langchain_community.chat_models import ChatOpenAI from langchain.chains.combine_documents import create_stuff_documents_chain from langchain.chains import create_retrieval_chain from langchain import hub retrieval_qa_chat_prompt = hub.pull("langchain-ai/retrieval-qa-chat") llm = ChatOpenAI() retriever = ... combine_docs_chain = create_stuff_documents_chain( llm, retrieval_qa_chat_prompt ) retrieval_chain = create_retrieval_chain(retriever, combine_docs_chain) chain.invoke({"input": "..."}) cSs|dS)Ninput)xrrR/var/www/html/zoom/venv/lib/python3.10/site-packages/langchain/chains/retrieval.py=sz(create_retrieval_chain..retrieve_documents)run_name)context)answerretrieval_chain) isinstancerr assign with_config)r r retrieval_docsrrrrcreate_retrieval_chain s .  rN)r r r r rr) __future__rtypingrrrlangchain_core.retrieversrrlangchain_core.runnablesrr rrrrrs