load_query_constructor_chain() — langchain Function Reference

Source Code

libs/langchain/langchain_classic/chains/query_constructor/base.py lines 273–323

def load_query_constructor_chain(
    llm: BaseLanguageModel,
    document_contents: str,
    attribute_info: Sequence[AttributeInfo | dict],
    examples: list | None = None,
    allowed_comparators: Sequence[Comparator] = tuple(Comparator),
    allowed_operators: Sequence[Operator] = tuple(Operator),
    enable_limit: bool = False,  # noqa: FBT001,FBT002
    schema_prompt: BasePromptTemplate | None = None,
    **kwargs: Any,
) -> LLMChain:
    """Load a query constructor chain.

    Args:
        llm: BaseLanguageModel to use for the chain.
        document_contents: The contents of the document to be queried.
        attribute_info: Sequence of attributes in the document.
        examples: Optional list of examples to use for the chain.
        allowed_comparators: Sequence of allowed comparators. Defaults to all
            `Comparator` objects.
        allowed_operators: Sequence of allowed operators. Defaults to all `Operator`
            objects.
        enable_limit: Whether to enable the limit operator.
        schema_prompt: Prompt for describing query schema. Should have string input
            variables allowed_comparators and allowed_operators.
        **kwargs: Arbitrary named params to pass to LLMChain.

    Returns:
        A LLMChain that can be used to construct queries.
    """
    prompt = get_query_constructor_prompt(
        document_contents,
        attribute_info,
        examples=examples,
        allowed_comparators=allowed_comparators,
        allowed_operators=allowed_operators,
        enable_limit=enable_limit,
        schema_prompt=schema_prompt,
    )
    allowed_attributes = [
        ainfo.name if isinstance(ainfo, AttributeInfo) else ainfo["name"]
        for ainfo in attribute_info
    ]
    output_parser = StructuredQueryOutputParser.from_components(
        allowed_comparators=allowed_comparators,
        allowed_operators=allowed_operators,
        allowed_attributes=allowed_attributes,
    )
    # For backwards compatibility.
    prompt.output_parser = output_parser
    return LLMChain(llm=llm, prompt=prompt, output_parser=output_parser, **kwargs)