search() — langchain Function Reference

Source Code

libs/core/langchain_core/vectorstores/base.py lines 293–324

    def search(self, query: str, search_type: str, **kwargs: Any) -> list[Document]:
        """Return docs most similar to query using a specified search type.

        Args:
            query: Input text.
            search_type: Type of search to perform.

                Can be `'similarity'`, `'mmr'`, or `'similarity_score_threshold'`.
            **kwargs: Arguments to pass to the search method.

        Returns:
            List of `Document` objects most similar to the query.

        Raises:
            ValueError: If `search_type` is not one of `'similarity'`,
                `'mmr'`, or `'similarity_score_threshold'`.
        """
        if search_type == "similarity":
            return self.similarity_search(query, **kwargs)
        if search_type == "similarity_score_threshold":
            docs_and_similarities = self.similarity_search_with_relevance_scores(
                query, **kwargs
            )
            return [doc for doc, _ in docs_and_similarities]
        if search_type == "mmr":
            return self.max_marginal_relevance_search(query, **kwargs)
        msg = (
            f"search_type of {search_type} not allowed. Expected "
            "search_type to be 'similarity', 'similarity_score_threshold'"
            " or 'mmr'."
        )
        raise ValueError(msg)