_load_map_reduce_chain() — langchain Function Reference

Architecture documentation for the _load_map_reduce_chain() function in chain.py from the langchain codebase.

Function python AgentOrchestration ClassicChains

Entity Profile

AgentOrchestration→ ClassicChains→ _load_map_reduce_chain() — langchain Function Reference

Dependency Diagram

graph TD
  93985420_65fc_2070_7048_c77879117460["_load_map_reduce_chain()"]
  7bff8b59_614d_4352_11dd_db15fa7a7056["chain.py"]
  93985420_65fc_2070_7048_c77879117460 -->|defined in| 7bff8b59_614d_4352_11dd_db15fa7a7056
  style 93985420_65fc_2070_7048_c77879117460 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/langchain/langchain_classic/chains/question_answering/chain.py lines 102–183

def _load_map_reduce_chain(
    llm: BaseLanguageModel,
    *,
    question_prompt: BasePromptTemplate | None = None,
    combine_prompt: BasePromptTemplate | None = None,
    combine_document_variable_name: str = "summaries",
    map_reduce_document_variable_name: str = "context",
    collapse_prompt: BasePromptTemplate | None = None,
    reduce_llm: BaseLanguageModel | None = None,
    collapse_llm: BaseLanguageModel | None = None,
    verbose: bool | None = None,
    callback_manager: BaseCallbackManager | None = None,
    callbacks: Callbacks = None,
    token_max: int = 3000,
    **kwargs: Any,
) -> MapReduceDocumentsChain:
    _question_prompt = (
        question_prompt or map_reduce_prompt.QUESTION_PROMPT_SELECTOR.get_prompt(llm)
    )
    _combine_prompt = (
        combine_prompt or map_reduce_prompt.COMBINE_PROMPT_SELECTOR.get_prompt(llm)
    )
    map_chain = LLMChain(
        llm=llm,
        prompt=_question_prompt,
        verbose=verbose,
        callback_manager=callback_manager,
        callbacks=callbacks,
    )
    _reduce_llm = reduce_llm or llm
    reduce_chain = LLMChain(
        llm=_reduce_llm,
        prompt=_combine_prompt,
        verbose=verbose,
        callback_manager=callback_manager,
        callbacks=callbacks,
    )
    # TODO: document prompt
    combine_documents_chain = StuffDocumentsChain(
        llm_chain=reduce_chain,
        document_variable_name=combine_document_variable_name,
        verbose=verbose,
        callback_manager=callback_manager,
        callbacks=callbacks,
    )
    if collapse_prompt is None:
        collapse_chain = None
        if collapse_llm is not None:
            msg = (
                "collapse_llm provided, but collapse_prompt was not: please "
                "provide one or stop providing collapse_llm."
            )
            raise ValueError(msg)
    else:
        _collapse_llm = collapse_llm or llm
        collapse_chain = StuffDocumentsChain(
            llm_chain=LLMChain(
                llm=_collapse_llm,
                prompt=collapse_prompt,
                verbose=verbose,
                callback_manager=callback_manager,
                callbacks=callbacks,
            ),
            document_variable_name=combine_document_variable_name,
            verbose=verbose,
            callback_manager=callback_manager,
        )
    reduce_documents_chain = ReduceDocumentsChain(
        combine_documents_chain=combine_documents_chain,
        collapse_documents_chain=collapse_chain,
        token_max=token_max,
        verbose=verbose,
    )
    return MapReduceDocumentsChain(
        llm_chain=map_chain,
        document_variable_name=map_reduce_document_variable_name,
        reduce_documents_chain=reduce_documents_chain,
        verbose=verbose,
        callback_manager=callback_manager,
        callbacks=callbacks,
        **kwargs,