vector_field,
            text_field,
            mapping,
        )
[docs]    def similarity_search(
        self, query: str, k: int = 4, **kwargs: Any
    ) -> List[Document]:
        """Return docs most similar to query.
        By default supports Approximate Search.
        Also supports Script Scoring and Painless Scripting.
        Args:
            query: Text to look up documents similar to.
            k: Number of Documents to return. Defaults to 4.
        Returns:
            List of Documents most similar to the query.
        Optional Args:
            vector_field: Document field embeddings are stored in. Defaults to
            "vector_field".
            text_field: Document field the text of the document is stored in. Defaults
            to "text".
            metadata_field: Document field that metadata is stored in. Defaults to
            "metadata".
            Can be set to a special value "*" to include the entire document.
        Optional Args for Approximate Search:
            search_type: "approximate_search"; default: "approximate_search"
            boolean_filter: A Boolean filter consists of a Boolean query that
            contains a k-NN query and a filter.
            subquery_clause: Query clause on the knn vector field; default: "must"
            lucene_filter: the Lucene algorithm decides whether to perform an exact
            k-NN search with pre-filtering or an approximate search with modified
            post-filtering.
        Optional Args for Script Scoring Search:
            search_type: "script_scoring"; default: "approximate_search"
            space_type: "l2", "l1", "linf", "cosinesimil", "innerproduct",
            "hammingbit"; default: "l2"
rtdocs_stable/api.python.langchain.com/en/stable/_modules/langchain/vectorstores/opensearch_vector_search.html