_load_vector_db_qa_with_sources_chain() — langchain Function Reference

Source Code

libs/langchain/langchain_classic/chains/loading.py lines 429–459

def _load_vector_db_qa_with_sources_chain(
    config: dict,
    **kwargs: Any,
) -> VectorDBQAWithSourcesChain:
    if "vectorstore" in kwargs:
        vectorstore = kwargs.pop("vectorstore")
    else:
        msg = "`vectorstore` must be present."
        raise ValueError(msg)
    if "combine_documents_chain" in config:
        combine_documents_chain_config = config.pop("combine_documents_chain")
        combine_documents_chain = load_chain_from_config(
            combine_documents_chain_config,
            **kwargs,
        )
    elif "combine_documents_chain_path" in config:
        combine_documents_chain = load_chain(
            config.pop("combine_documents_chain_path"),
            **kwargs,
        )
    else:
        msg = (
            "One of `combine_documents_chain` or "
            "`combine_documents_chain_path` must be present."
        )
        raise ValueError(msg)
    return VectorDBQAWithSourcesChain(
        combine_documents_chain=combine_documents_chain,
        vectorstore=vectorstore,
        **config,
    )