neighbors, _ = self.project.projections[0].vector_search(
                queries=embedding, k=k
            )
            datas = self.project.get_data(ids=neighbors[0])
        docs = [
            Document(page_content=datas[i]["text"], metadata=datas[i])
            for i, neighbor in enumerate(neighbors)
        ]
        return docs
[docs]    @classmethod
    def from_texts(
        cls: Type[AtlasDB],
        texts: List[str],
        embedding: Optional[Embeddings] = None,
        metadatas: Optional[List[dict]] = None,
        ids: Optional[List[str]] = None,
        name: Optional[str] = None,
        api_key: Optional[str] = None,
        description: str = "A description for your project",
        is_public: bool = True,
        reset_project_if_exists: bool = False,
        index_kwargs: Optional[dict] = None,
        **kwargs: Any,
    ) -> AtlasDB:
        """Create an AtlasDB vectorstore from a raw documents.
        Args:
            texts (List[str]): The list of texts to ingest.
            name (str): Name of the project to create.
            api_key (str): Your nomic API key,
            embedding (Optional[Embeddings]): Embedding function. Defaults to None.
            metadatas (Optional[List[dict]]): List of metadatas. Defaults to None.
            ids (Optional[List[str]]): Optional list of document IDs. If None,
                ids will be auto created
            description (str): A description for your project.
            is_public (bool): Whether your project is publicly accessible.
                True by default.
            reset_project_if_exists (bool): Whether to reset this project if it


already exists. Default False.
                Generally userful during development and testing.
            index_kwargs (Optional[dict]): Dict of kwargs for index creation.
                See https://docs.nomic.ai/atlas_api.html
        Returns:
            AtlasDB: Nomic's neural database and finest rhizomatic instrument
        """
        if name is None or api_key is None:
            raise ValueError("`name` and `api_key` cannot be None.")
        # Inject relevant kwargs
        all_index_kwargs = {"name": name + "_index", "indexed_field": "text"}
        if index_kwargs is not None:
            for k, v in index_kwargs.items():
                all_index_kwargs[k] = v
        # Build project
        atlasDB = cls(
            name,
            embedding_function=embedding,
            api_key=api_key,
            description="A description for your project",
            is_public=is_public,
            reset_project_if_exists=reset_project_if_exists,
        )
        with atlasDB.project.wait_for_project_lock():
            atlasDB.add_texts(texts=texts, metadatas=metadatas, ids=ids)
            atlasDB.create_index(**all_index_kwargs)
        return atlasDB
[docs]    @classmethod
    def from_documents(
        cls: Type[AtlasDB],
        documents: List[Document],
        embedding: Optional[Embeddings] = None,
        ids: Optional[List[str]] = None,
        name: Optional[str] = None,
        api_key: Optional[str] = None,
        persist_directory: Optional[str] = None,
        description: str = "A description for your project",
        is_public: bool = True,
        reset_project_if_exists: bool = False,
        index_kwargs: Optional[dict] = None,


**kwargs: Any,
    ) -> AtlasDB:
        """Create an AtlasDB vectorstore from a list of documents.
        Args:
            name (str): Name of the collection to create.
            api_key (str): Your nomic API key,
            documents (List[Document]): List of documents to add to the vectorstore.
            embedding (Optional[Embeddings]): Embedding function. Defaults to None.
            ids (Optional[List[str]]): Optional list of document IDs. If None,
                ids will be auto created
            description (str): A description for your project.
            is_public (bool): Whether your project is publicly accessible.
                True by default.
            reset_project_if_exists (bool): Whether to reset this project if
                it already exists. Default False.
                Generally userful during development and testing.
            index_kwargs (Optional[dict]): Dict of kwargs for index creation.
                See https://docs.nomic.ai/atlas_api.html
        Returns:
            AtlasDB: Nomic's neural database and finest rhizomatic instrument
        """
        if name is None or api_key is None:
            raise ValueError("`name` and `api_key` cannot be None.")
        texts = [doc.page_content for doc in documents]
        metadatas = [doc.metadata for doc in documents]
        return cls.from_texts(
            name=name,
            api_key=api_key,
            texts=texts,
            embedding=embedding,
            metadatas=metadatas,
            ids=ids,
            description=description,
            is_public=is_public,
            reset_project_if_exists=reset_project_if_exists,
            index_kwargs=index_kwargs,
        )
By Harrison Chase

      © Copyright 2023, Harrison Chase.


Last updated on Jun 04, 2023.


Source code for langchain.vectorstores.sklearn
""" Wrapper around scikit-learn NearestNeighbors implementation.
The vector store can be persisted in json, bson or parquet format.
"""
import json
import math
import os
from abc import ABC, abstractmethod
from typing import Any, Dict, Iterable, List, Literal, Optional, Tuple, Type
from uuid import uuid4
from langchain.docstore.document import Document
from langchain.embeddings.base import Embeddings
from langchain.utils import guard_import
from langchain.vectorstores.base import VectorStore
from langchain.vectorstores.utils import maximal_marginal_relevance
DEFAULT_K = 4  # Number of Documents to return.
DEFAULT_FETCH_K = 20  # Number of Documents to initially fetch during MMR search.
class BaseSerializer(ABC):
    """Abstract base class for saving and loading data."""
    def __init__(self, persist_path: str) -> None:
        self.persist_path = persist_path
    @classmethod
    @abstractmethod
    def extension(cls) -> str:
        """The file extension suggested by this serializer (without dot)."""
    @abstractmethod
    def save(self, data: Any) -> None:
        """Saves the data to the persist_path"""
    @abstractmethod
    def load(self) -> Any:
        """Loads the data from the persist_path"""
class JsonSerializer(BaseSerializer):
    """Serializes data in json using the json package from python standard library."""
    @classmethod
    def extension(cls) -> str:
        return "json"
    def save(self, data: Any) -> None:
        with open(self.persist_path, "w") as fp:
            json.dump(data, fp)
    def load(self) -> Any:
        with open(self.persist_path, "r") as fp:


return json.load(fp)
class BsonSerializer(BaseSerializer):
    """Serializes data in binary json using the bson python package."""
    def __init__(self, persist_path: str) -> None:
        super().__init__(persist_path)
        self.bson = guard_import("bson")
    @classmethod
    def extension(cls) -> str:
        return "bson"
    def save(self, data: Any) -> None:
        with open(self.persist_path, "wb") as fp:
            fp.write(self.bson.dumps(data))
    def load(self) -> Any:
        with open(self.persist_path, "rb") as fp:
            return self.bson.loads(fp.read())
class ParquetSerializer(BaseSerializer):
    """Serializes data in Apache Parquet format using the pyarrow package."""
    def __init__(self, persist_path: str) -> None:
        super().__init__(persist_path)
        self.pd = guard_import("pandas")
        self.pa = guard_import("pyarrow")
        self.pq = guard_import("pyarrow.parquet")
    @classmethod
    def extension(cls) -> str:
        return "parquet"
    def save(self, data: Any) -> None:
        df = self.pd.DataFrame(data)
        table = self.pa.Table.from_pandas(df)
        if os.path.exists(self.persist_path):
            backup_path = str(self.persist_path) + "-backup"
            os.rename(self.persist_path, backup_path)
            try:
                self.pq.write_table(table, self.persist_path)
            except Exception as exc:
                os.rename(backup_path, self.persist_path)
                raise exc
            else:
                os.remove(backup_path)
        else:


self.pq.write_table(table, self.persist_path)
    def load(self) -> Any:
        table = self.pq.read_table(self.persist_path)
        df = table.to_pandas()
        return {col: series.tolist() for col, series in df.items()}
SERIALIZER_MAP: Dict[str, Type[BaseSerializer]] = {
    "json": JsonSerializer,
    "bson": BsonSerializer,
    "parquet": ParquetSerializer,
}
class SKLearnVectorStoreException(RuntimeError):
    pass
[docs]class SKLearnVectorStore(VectorStore):
    """A simple in-memory vector store based on the scikit-learn library
    NearestNeighbors implementation."""
    def __init__(
        self,
        embedding: Embeddings,
        *,
        persist_path: Optional[str] = None,
        serializer: Literal["json", "bson", "parquet"] = "json",
        metric: str = "cosine",
        **kwargs: Any,
    ) -> None:
        np = guard_import("numpy")
        sklearn_neighbors = guard_import("sklearn.neighbors", pip_name="scikit-learn")
        # non-persistent properties
        self._np = np
        self._neighbors = sklearn_neighbors.NearestNeighbors(metric=metric, **kwargs)
        self._neighbors_fitted = False
        self._embedding_function = embedding
        self._persist_path = persist_path
        self._serializer: Optional[BaseSerializer] = None
        if self._persist_path is not None:
            serializer_cls = SERIALIZER_MAP[serializer]
            self._serializer = serializer_cls(persist_path=self._persist_path)
        # data properties
        self._embeddings: List[List[float]] = []
        self._texts: List[str] = []


self._metadatas: List[dict] = []
        self._ids: List[str] = []
        # cache properties
        self._embeddings_np: Any = np.asarray([])
        if self._persist_path is not None and os.path.isfile(self._persist_path):
            self._load()
[docs]    def persist(self) -> None:
        if self._serializer is None:
            raise SKLearnVectorStoreException(
                "You must specify a persist_path on creation to persist the "
                "collection."
            )
        data = {
            "ids": self._ids,
            "texts": self._texts,
            "metadatas": self._metadatas,
            "embeddings": self._embeddings,
        }
        self._serializer.save(data)
    def _load(self) -> None:
        if self._serializer is None:
            raise SKLearnVectorStoreException(
                "You must specify a persist_path on creation to load the " "collection."
            )
        data = self._serializer.load()
        self._embeddings = data["embeddings"]
        self._texts = data["texts"]
        self._metadatas = data["metadatas"]
        self._ids = data["ids"]
        self._update_neighbors()
[docs]    def add_texts(
        self,
        texts: Iterable[str],
        metadatas: Optional[List[dict]] = None,
        ids: Optional[List[str]] = None,
        **kwargs: Any,
    ) -> List[str]:
        _texts = list(texts)
        _ids = ids or [str(uuid4()) for _ in _texts]
        self._texts.extend(_texts)


self._embeddings.extend(self._embedding_function.embed_documents(_texts))
        self._metadatas.extend(metadatas or ([{}] * len(_texts)))
        self._ids.extend(_ids)
        self._update_neighbors()
        return _ids
    def _update_neighbors(self) -> None:
        if len(self._embeddings) == 0:
            raise SKLearnVectorStoreException(
                "No data was added to SKLearnVectorStore."
            )
        self._embeddings_np = self._np.asarray(self._embeddings)
        self._neighbors.fit(self._embeddings_np)
        self._neighbors_fitted = True
    def _similarity_index_search_with_score(
        self, query_embedding: List[float], *, k: int = DEFAULT_K, **kwargs: Any
    ) -> List[Tuple[int, float]]:
        """Search k embeddings similar to the query embedding. Returns a list of
        (index, distance) tuples."""
        if not self._neighbors_fitted:
            raise SKLearnVectorStoreException(
                "No data was added to SKLearnVectorStore."
            )
        neigh_dists, neigh_idxs = self._neighbors.kneighbors(
            [query_embedding], n_neighbors=k
        )
        return list(zip(neigh_idxs[0], neigh_dists[0]))
[docs]    def similarity_search_with_score(
        self, query: str, *, k: int = DEFAULT_K, **kwargs: Any
    ) -> List[Tuple[Document, float]]:
        query_embedding = self._embedding_function.embed_query(query)
        indices_dists = self._similarity_index_search_with_score(
            query_embedding, k=k, **kwargs
        )
        return [
            (
                Document(
                    page_content=self._texts[idx],


metadata={"id": self._ids[idx], **self._metadatas[idx]},
                ),
                dist,
            )
            for idx, dist in indices_dists
        ]
[docs]    def similarity_search(
        self, query: str, k: int = DEFAULT_K, **kwargs: Any
    ) -> List[Document]:
        docs_scores = self.similarity_search_with_score(query, k=k, **kwargs)
        return [doc for doc, _ in docs_scores]
    def _similarity_search_with_relevance_scores(
        self, query: str, k: int = DEFAULT_K, **kwargs: Any
    ) -> List[Tuple[Document, float]]:
        docs_dists = self.similarity_search_with_score(query, k=k, **kwargs)
        docs, dists = zip(*docs_dists)
        scores = [1 / math.exp(dist) for dist in dists]
        return list(zip(list(docs), scores))
[docs]    def max_marginal_relevance_search_by_vector(
        self,
        embedding: List[float],
        k: int = DEFAULT_K,
        fetch_k: int = DEFAULT_FETCH_K,
        lambda_mult: float = 0.5,
        **kwargs: Any,
    ) -> List[Document]:
        """Return docs selected using the maximal marginal relevance.
        Maximal marginal relevance optimizes for similarity to query AND diversity
        among selected documents.
        Args:
            embedding: Embedding to look up documents similar to.
            k: Number of Documents to return. Defaults to 4.
            fetch_k: Number of Documents to fetch to pass to MMR algorithm.
            lambda_mult: Number between 0 and 1 that determines the degree
                        of diversity among the results with 0 corresponding


to maximum diversity and 1 to minimum diversity.
                        Defaults to 0.5.
        Returns:
            List of Documents selected by maximal marginal relevance.
        """
        indices_dists = self._similarity_index_search_with_score(
            embedding, k=fetch_k, **kwargs
        )
        indices, _ = zip(*indices_dists)
        result_embeddings = self._embeddings_np[indices,]
        mmr_selected = maximal_marginal_relevance(
            self._np.array(embedding, dtype=self._np.float32),
            result_embeddings,
            k=k,
            lambda_mult=lambda_mult,
        )
        mmr_indices = [indices[i] for i in mmr_selected]
        return [
            Document(
                page_content=self._texts[idx],
                metadata={"id": self._ids[idx], **self._metadatas[idx]},
            )
            for idx in mmr_indices
        ]
[docs]    def max_marginal_relevance_search(
        self,
        query: str,
        k: int = DEFAULT_K,
        fetch_k: int = DEFAULT_FETCH_K,
        lambda_mult: float = 0.5,
        **kwargs: Any,
    ) -> List[Document]:
        """Return docs selected using the maximal marginal relevance.
        Maximal marginal relevance optimizes for similarity to query AND diversity
        among selected documents.
        Args:
            query: Text to look up documents similar to.
            k: Number of Documents to return. Defaults to 4.
            fetch_k: Number of Documents to fetch to pass to MMR algorithm.
            lambda_mult: Number between 0 and 1 that determines the degree
                        of diversity among the results with 0 corresponding
                        to maximum diversity and 1 to minimum diversity.


Defaults to 0.5.
        Returns:
            List of Documents selected by maximal marginal relevance.
        """
        if self._embedding_function is None:
            raise ValueError(
                "For MMR search, you must specify an embedding function on creation."
            )
        embedding = self._embedding_function.embed_query(query)
        docs = self.max_marginal_relevance_search_by_vector(
            embedding, k, fetch_k, lambda_mul=lambda_mult
        )
        return docs
[docs]    @classmethod
    def from_texts(
        cls,
        texts: List[str],
        embedding: Embeddings,
        metadatas: Optional[List[dict]] = None,
        ids: Optional[List[str]] = None,
        persist_path: Optional[str] = None,
        **kwargs: Any,
    ) -> "SKLearnVectorStore":
        vs = SKLearnVectorStore(embedding, persist_path=persist_path, **kwargs)
        vs.add_texts(texts, metadatas=metadatas, ids=ids)
        return vs
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 04, 2023.


Source code for langchain.vectorstores.vectara
"""Wrapper around Vectara vector database."""
from __future__ import annotations
import json
import logging
import os
from hashlib import md5
from typing import Any, Iterable, List, Optional, Tuple, Type
import requests
from pydantic import Field
from langchain.embeddings.base import Embeddings
from langchain.schema import Document
from langchain.vectorstores.base import VectorStore, VectorStoreRetriever
[docs]class Vectara(VectorStore):
    """Implementation of Vector Store using Vectara (https://vectara.com).
    Example:
        .. code-block:: python
            from langchain.vectorstores import Vectara
            vectorstore = Vectara(
                vectara_customer_id=vectara_customer_id,
                vectara_corpus_id=vectara_corpus_id,
                vectara_api_key=vectara_api_key
            )
    """
    def __init__(
        self,
        vectara_customer_id: Optional[str] = None,
        vectara_corpus_id: Optional[str] = None,
        vectara_api_key: Optional[str] = None,
    ):
        """Initialize with Vectara API."""
        self._vectara_customer_id = vectara_customer_id or os.environ.get(
            "VECTARA_CUSTOMER_ID"
        )
        self._vectara_corpus_id = vectara_corpus_id or os.environ.get(
            "VECTARA_CORPUS_ID"
        )
        self._vectara_api_key = vectara_api_key or os.environ.get("VECTARA_API_KEY")
        if (
            self._vectara_customer_id is None
            or self._vectara_corpus_id is None
            or self._vectara_api_key is None
        ):
            logging.warning(


"Cant find Vectara credentials, customer_id or corpus_id in "
                "environment."
            )
        else:
            logging.debug(f"Using corpus id {self._vectara_corpus_id}")
        self._session = requests.Session()  # to reuse connections
    def _get_post_headers(self) -> dict:
        """Returns headers that should be attached to each post request."""
        return {
            "x-api-key": self._vectara_api_key,
            "customer-id": self._vectara_customer_id,
            "Content-Type": "application/json",
        }
    def _delete_doc(self, doc_id: str) -> bool:
        """
        Delete a document from the Vectara corpus.
        Args:
            url (str): URL of the page to delete.
            doc_id (str): ID of the document to delete.
        Returns:
            bool: True if deletion was successful, False otherwise.
        """
        body = {
            "customer_id": self._vectara_customer_id,
            "corpus_id": self._vectara_corpus_id,
            "document_id": doc_id,
        }
        response = self._session.post(
            "https://api.vectara.io/v1/delete-doc",
            data=json.dumps(body),
            verify=True,
            headers=self._get_post_headers(),
        )
        if response.status_code != 200:
            logging.error(
                f"Delete request failed for doc_id = {doc_id} with status code "
                f"{response.status_code}, reason {response.reason}, text "
                f"{response.text}"
            )
            return False
        return True
    def _index_doc(self, doc_id: str, text: str, metadata: dict) -> bool:


request: dict[str, Any] = {}
        request["customer_id"] = self._vectara_customer_id
        request["corpus_id"] = self._vectara_corpus_id
        request["document"] = {
            "document_id": doc_id,
            "metadataJson": json.dumps(metadata),
            "section": [{"text": text, "metadataJson": json.dumps(metadata)}],
        }
        response = self._session.post(
            headers=self._get_post_headers(),
            url="https://api.vectara.io/v1/index",
            data=json.dumps(request),
            timeout=30,
            verify=True,
        )
        status_code = response.status_code
        result = response.json()
        status_str = result["status"]["code"] if "status" in result else None
        if status_code == 409 or (status_str and status_str == "ALREADY_EXISTS"):
            return False
        else:
            return True
[docs]    def add_texts(
        self,
        texts: Iterable[str],
        metadatas: Optional[List[dict]] = None,
        **kwargs: Any,
    ) -> List[str]:
        """Run more texts through the embeddings and add to the vectorstore.
        Args:
            texts: Iterable of strings to add to the vectorstore.
            metadatas: Optional list of metadatas associated with the texts.
        Returns:
            List of ids from adding the texts into the vectorstore.
        """
        ids = [md5(text.encode("utf-8")).hexdigest() for text in texts]
        for i, doc in enumerate(texts):
            doc_id = ids[i]
            metadata = metadatas[i] if metadatas else {}
            succeeded = self._index_doc(doc_id, doc, metadata)


if not succeeded:
                self._delete_doc(doc_id)
                self._index_doc(doc_id, doc, metadata)
        return ids
[docs]    def similarity_search_with_score(
        self,
        query: str,
        k: int = 5,
        alpha: float = 0.025,
        filter: Optional[str] = None,
        **kwargs: Any,
    ) -> List[Tuple[Document, float]]:
        """Return Vectara documents most similar to query, along with scores.
        Args:
            query: Text to look up documents similar to.
            k: Number of Documents to return. Defaults to 5.
            alpha: parameter for hybrid search (called "lambda" in Vectara
                documentation).
            filter: Dictionary of argument(s) to filter on metadata. For example a
                filter can be "doc.rating > 3.0 and part.lang = 'deu'"} see
                https://docs.vectara.com/docs/search-apis/sql/filter-overview
                for more details.
        Returns:
            List of Documents most similar to the query and score for each.
        """
        response = self._session.post(
            headers=self._get_post_headers(),
            url="https://api.vectara.io/v1/query",
            data=json.dumps(
                {
                    "query": [
                        {
                            "query": query,
                            "start": 0,
                            "num_results": k,
                            "context_config": {
                                "sentences_before": 3,
                                "sentences_after": 3,
                            },
                            "corpus_key": [
                                {
                                    "customer_id": self._vectara_customer_id,
                                    "corpus_id": self._vectara_corpus_id,


"metadataFilter": filter,
                                    "lexical_interpolation_config": {"lambda": alpha},
                                }
                            ],
                        }
                    ]
                }
            ),
            timeout=10,
        )
        if response.status_code != 200:
            logging.error(
                "Query failed %s",
                f"(code {response.status_code}, reason {response.reason}, details "
                f"{response.text})",
            )
            return []
        result = response.json()
        responses = result["responseSet"][0]["response"]
        vectara_default_metadata = ["lang", "len", "offset"]
        docs = [
            (
                Document(
                    page_content=x["text"],
                    metadata={
                        m["name"]: m["value"]
                        for m in x["metadata"]
                        if m["name"] not in vectara_default_metadata
                    },
                ),
                x["score"],
            )
            for x in responses
        ]
        return docs
[docs]    def similarity_search(
        self,
        query: str,
        k: int = 5,
        alpha: float = 0.025,
        filter: Optional[str] = None,
        **kwargs: Any,
    ) -> List[Document]:
        """Return Vectara documents most similar to query, along with scores.
        Args:
            query: Text to look up documents similar to.
            k: Number of Documents to return. Defaults to 5.
            filter: Dictionary of argument(s) to filter on metadata. For example a
                filter can be "doc.rating > 3.0 and part.lang = 'deu'"} see
                https://docs.vectara.com/docs/search-apis/sql/filter-overview for more
                details.
        Returns:


List of Documents most similar to the query
        """
        docs_and_scores = self.similarity_search_with_score(
            query, k=k, alpha=alpha, filter=filter, **kwargs
        )
        return [doc for doc, _ in docs_and_scores]
[docs]    @classmethod
    def from_texts(
        cls: Type[Vectara],
        texts: List[str],
        embedding: Optional[Embeddings] = None,
        metadatas: Optional[List[dict]] = None,
        **kwargs: Any,
    ) -> Vectara:
        """Construct Vectara wrapper from raw documents.
        This is intended to be a quick way to get started.
        Example:
            .. code-block:: python
                from langchain import Vectara
                vectara = Vectara.from_texts(
                    texts,
                    vectara_customer_id=customer_id,
                    vectara_corpus_id=corpus_id,
                    vectara_api_key=api_key,
                )
        """
        # Note: Vectara generates its own embeddings, so we ignore the provided
        # embeddings (required by interface)
        vectara = cls(**kwargs)
        vectara.add_texts(texts, metadatas)
        return vectara
[docs]    def as_retriever(self, **kwargs: Any) -> VectaraRetriever:
        return VectaraRetriever(vectorstore=self, **kwargs)
class VectaraRetriever(VectorStoreRetriever):
    vectorstore: Vectara
    search_kwargs: dict = Field(default_factory=lambda: {"alpha": 0.025, "k": 5})
    """Search params.
        k: Number of Documents to return. Defaults to 5.
        alpha: parameter for hybrid search (called "lambda" in Vectara


documentation).
        filter: Dictionary of argument(s) to filter on metadata. For example a
            filter can be "doc.rating > 3.0 and part.lang = 'deu'"} see
            https://docs.vectara.com/docs/search-apis/sql/filter-overview
            for more details.
    """
    def add_texts(
        self, texts: List[str], metadatas: Optional[List[dict]] = None
    ) -> None:
        """Add text to the Vectara vectorstore.
        Args:
            texts (List[str]): The text
            metadatas (List[dict]): Metadata dicts, must line up with existing store
        """
        self.vectorstore.add_texts(texts, metadatas)
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 04, 2023.


Source code for langchain.vectorstores.zilliz
from __future__ import annotations
import logging
from typing import Any, List, Optional
from langchain.embeddings.base import Embeddings
from langchain.vectorstores.milvus import Milvus
logger = logging.getLogger(__name__)
[docs]class Zilliz(Milvus):
    def _create_index(self) -> None:
        """Create a index on the collection"""
        from pymilvus import Collection, MilvusException
        if isinstance(self.col, Collection) and self._get_index() is None:
            try:
                # If no index params, use a default AutoIndex based one
                if self.index_params is None:
                    self.index_params = {
                        "metric_type": "L2",
                        "index_type": "AUTOINDEX",
                        "params": {},
                    }
                try:
                    self.col.create_index(
                        self._vector_field,
                        index_params=self.index_params,
                        using=self.alias,
                    )
                # If default did not work, most likely Milvus self-hosted
                except MilvusException:
                    # Use HNSW based index
                    self.index_params = {
                        "metric_type": "L2",
                        "index_type": "HNSW",
                        "params": {"M": 8, "efConstruction": 64},
                    }
                    self.col.create_index(
                        self._vector_field,
                        index_params=self.index_params,
                        using=self.alias,
                    )
                logger.debug(
                    "Successfully created an index on collection: %s",
                    self.collection_name,
                )
            except MilvusException as e:
                logger.error(
                    "Failed to create an index on collection: %s", self.collection_name


)
                raise e
[docs]    @classmethod
    def from_texts(
        cls,
        texts: List[str],
        embedding: Embeddings,
        metadatas: Optional[List[dict]] = None,
        collection_name: str = "LangChainCollection",
        connection_args: dict[str, Any] = {},
        consistency_level: str = "Session",
        index_params: Optional[dict] = None,
        search_params: Optional[dict] = None,
        drop_old: bool = False,
        **kwargs: Any,
    ) -> Zilliz:
        """Create a Zilliz collection, indexes it with HNSW, and insert data.
        Args:
            texts (List[str]): Text data.
            embedding (Embeddings): Embedding function.
            metadatas (Optional[List[dict]]): Metadata for each text if it exists.
                Defaults to None.
            collection_name (str, optional): Collection name to use. Defaults to
                "LangChainCollection".
            connection_args (dict[str, Any], optional): Connection args to use. Defaults
                to DEFAULT_MILVUS_CONNECTION.
            consistency_level (str, optional): Which consistency level to use. Defaults
                to "Session".
            index_params (Optional[dict], optional): Which index_params to use.
                Defaults to None.
            search_params (Optional[dict], optional): Which search params to use.
                Defaults to None.
            drop_old (Optional[bool], optional): Whether to drop the collection with
                that name if it exists. Defaults to False.
        Returns:
            Zilliz: Zilliz Vector Store
        """
        vector_db = cls(
            embedding_function=embedding,
            collection_name=collection_name,


connection_args=connection_args,
            consistency_level=consistency_level,
            index_params=index_params,
            search_params=search_params,
            drop_old=drop_old,
            **kwargs,
        )
        vector_db.add_texts(texts=texts, metadatas=metadatas)
        return vector_db
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 04, 2023.


Source code for langchain.vectorstores.base
"""Interface for vector stores."""
from __future__ import annotations
import asyncio
import warnings
from abc import ABC, abstractmethod
from functools import partial
from typing import Any, Dict, Iterable, List, Optional, Tuple, Type, TypeVar
from pydantic import BaseModel, Field, root_validator
from langchain.docstore.document import Document
from langchain.embeddings.base import Embeddings
from langchain.schema import BaseRetriever
VST = TypeVar("VST", bound="VectorStore")
[docs]class VectorStore(ABC):
    """Interface for vector stores."""
[docs]    @abstractmethod
    def add_texts(
        self,
        texts: Iterable[str],
        metadatas: Optional[List[dict]] = None,
        **kwargs: Any,
    ) -> List[str]:
        """Run more texts through the embeddings and add to the vectorstore.
        Args:
            texts: Iterable of strings to add to the vectorstore.
            metadatas: Optional list of metadatas associated with the texts.
            kwargs: vectorstore specific parameters
        Returns:
            List of ids from adding the texts into the vectorstore.
        """
[docs]    async def aadd_texts(
        self,
        texts: Iterable[str],
        metadatas: Optional[List[dict]] = None,
        **kwargs: Any,
    ) -> List[str]:
        """Run more texts through the embeddings and add to the vectorstore."""
        raise NotImplementedError
[docs]    def add_documents(self, documents: List[Document], **kwargs: Any) -> List[str]:
        """Run more documents through the embeddings and add to the vectorstore.
        Args:
            documents (List[Document]: Documents to add to the vectorstore.


Returns:
            List[str]: List of IDs of the added texts.
        """
        # TODO: Handle the case where the user doesn't provide ids on the Collection
        texts = [doc.page_content for doc in documents]
        metadatas = [doc.metadata for doc in documents]
        return self.add_texts(texts, metadatas, **kwargs)
[docs]    async def aadd_documents(
        self, documents: List[Document], **kwargs: Any
    ) -> List[str]:
        """Run more documents through the embeddings and add to the vectorstore.
        Args:
            documents (List[Document]: Documents to add to the vectorstore.
        Returns:
            List[str]: List of IDs of the added texts.
        """
        texts = [doc.page_content for doc in documents]
        metadatas = [doc.metadata for doc in documents]
        return await self.aadd_texts(texts, metadatas, **kwargs)
[docs]    def search(self, query: str, search_type: str, **kwargs: Any) -> List[Document]:
        """Return docs most similar to query using specified search type."""
        if search_type == "similarity":
            return self.similarity_search(query, **kwargs)
        elif search_type == "mmr":
            return self.max_marginal_relevance_search(query, **kwargs)
        else:
            raise ValueError(
                f"search_type of {search_type} not allowed. Expected "
                "search_type to be 'similarity' or 'mmr'."
            )
[docs]    async def asearch(
        self, query: str, search_type: str, **kwargs: Any
    ) -> List[Document]:
        """Return docs most similar to query using specified search type."""


if search_type == "similarity":
            return await self.asimilarity_search(query, **kwargs)
        elif search_type == "mmr":
            return await self.amax_marginal_relevance_search(query, **kwargs)
        else:
            raise ValueError(
                f"search_type of {search_type} not allowed. Expected "
                "search_type to be 'similarity' or 'mmr'."
            )
[docs]    @abstractmethod
    def similarity_search(
        self, query: str, k: int = 4, **kwargs: Any
    ) -> List[Document]:
        """Return docs most similar to query."""
[docs]    def similarity_search_with_relevance_scores(
        self,
        query: str,
        k: int = 4,
        **kwargs: Any,
    ) -> List[Tuple[Document, float]]:
        """Return docs and relevance scores in the range [0, 1].
        0 is dissimilar, 1 is most similar.
        Args:
            query: input text
            k: Number of Documents to return. Defaults to 4.
            **kwargs: kwargs to be passed to similarity search. Should include:
                score_threshold: Optional, a floating point value between 0 to 1 to
                    filter the resulting set of retrieved docs
        Returns:
            List of Tuples of (doc, similarity_score)
        """
        docs_and_similarities = self._similarity_search_with_relevance_scores(
            query, k=k, **kwargs
        )
        if any(
            similarity < 0.0 or similarity > 1.0
            for _, similarity in docs_and_similarities
        ):
            warnings.warn(
                "Relevance scores must be between"


f" 0 and 1, got {docs_and_similarities}"
            )
        score_threshold = kwargs.get("score_threshold")
        if score_threshold is not None:
            docs_and_similarities = [
                (doc, similarity)
                for doc, similarity in docs_and_similarities
                if similarity >= score_threshold
            ]
            if len(docs_and_similarities) == 0:
                warnings.warn(
                    f"No relevant docs were retrieved using the relevance score\
                          threshold {score_threshold}"
                )
        return docs_and_similarities
    def _similarity_search_with_relevance_scores(
        self,
        query: str,
        k: int = 4,
        **kwargs: Any,
    ) -> List[Tuple[Document, float]]:
        """Return docs and relevance scores, normalized on a scale from 0 to 1.
        0 is dissimilar, 1 is most similar.
        """
        raise NotImplementedError
[docs]    async def asimilarity_search_with_relevance_scores(
        self, query: str, k: int = 4, **kwargs: Any
    ) -> List[Tuple[Document, float]]:
        """Return docs most similar to query."""
        # This is a temporary workaround to make the similarity search
        # asynchronous. The proper solution is to make the similarity search
        # asynchronous in the vector store implementations.
        func = partial(self.similarity_search_with_relevance_scores, query, k, **kwargs)
        return await asyncio.get_event_loop().run_in_executor(None, func)
[docs]    async def asimilarity_search(
        self, query: str, k: int = 4, **kwargs: Any
    ) -> List[Document]:


"""Return docs most similar to query."""
        # This is a temporary workaround to make the similarity search
        # asynchronous. The proper solution is to make the similarity search
        # asynchronous in the vector store implementations.
        func = partial(self.similarity_search, query, k, **kwargs)
        return await asyncio.get_event_loop().run_in_executor(None, func)
[docs]    def similarity_search_by_vector(
        self, embedding: List[float], k: int = 4, **kwargs: Any
    ) -> List[Document]:
        """Return docs most similar to embedding vector.
        Args:
            embedding: Embedding to look up documents similar to.
            k: Number of Documents to return. Defaults to 4.
        Returns:
            List of Documents most similar to the query vector.
        """
        raise NotImplementedError
[docs]    async def asimilarity_search_by_vector(
        self, embedding: List[float], k: int = 4, **kwargs: Any
    ) -> List[Document]:
        """Return docs most similar to embedding vector."""
        # This is a temporary workaround to make the similarity search
        # asynchronous. The proper solution is to make the similarity search
        # asynchronous in the vector store implementations.
        func = partial(self.similarity_search_by_vector, embedding, k, **kwargs)
        return await asyncio.get_event_loop().run_in_executor(None, func)
[docs]    def max_marginal_relevance_search(
        self,
        query: str,
        k: int = 4,
        fetch_k: int = 20,
        lambda_mult: float = 0.5,
        **kwargs: Any,
    ) -> List[Document]:
        """Return docs selected using the maximal marginal relevance.


Maximal marginal relevance optimizes for similarity to query AND diversity
        among selected documents.
        Args:
            query: Text to look up documents similar to.
            k: Number of Documents to return. Defaults to 4.
            fetch_k: Number of Documents to fetch to pass to MMR algorithm.
            lambda_mult: Number between 0 and 1 that determines the degree
                        of diversity among the results with 0 corresponding
                        to maximum diversity and 1 to minimum diversity.
                        Defaults to 0.5.
        Returns:
            List of Documents selected by maximal marginal relevance.
        """
        raise NotImplementedError
[docs]    async def amax_marginal_relevance_search(
        self,
        query: str,
        k: int = 4,
        fetch_k: int = 20,
        lambda_mult: float = 0.5,
        **kwargs: Any,
    ) -> List[Document]:
        """Return docs selected using the maximal marginal relevance."""
        # This is a temporary workaround to make the similarity search
        # asynchronous. The proper solution is to make the similarity search
        # asynchronous in the vector store implementations.
        func = partial(
            self.max_marginal_relevance_search, query, k, fetch_k, lambda_mult, **kwargs
        )
        return await asyncio.get_event_loop().run_in_executor(None, func)
[docs]    def max_marginal_relevance_search_by_vector(
        self,
        embedding: List[float],
        k: int = 4,
        fetch_k: int = 20,
        lambda_mult: float = 0.5,
        **kwargs: Any,
    ) -> List[Document]:
        """Return docs selected using the maximal marginal relevance.


Maximal marginal relevance optimizes for similarity to query AND diversity
        among selected documents.
        Args:
            embedding: Embedding to look up documents similar to.
            k: Number of Documents to return. Defaults to 4.
            fetch_k: Number of Documents to fetch to pass to MMR algorithm.
            lambda_mult: Number between 0 and 1 that determines the degree
                        of diversity among the results with 0 corresponding
                        to maximum diversity and 1 to minimum diversity.
                        Defaults to 0.5.
        Returns:
            List of Documents selected by maximal marginal relevance.
        """
        raise NotImplementedError
[docs]    async def amax_marginal_relevance_search_by_vector(
        self,
        embedding: List[float],
        k: int = 4,
        fetch_k: int = 20,
        lambda_mult: float = 0.5,
        **kwargs: Any,
    ) -> List[Document]:
        """Return docs selected using the maximal marginal relevance."""
        raise NotImplementedError
[docs]    @classmethod
    def from_documents(
        cls: Type[VST],
        documents: List[Document],
        embedding: Embeddings,
        **kwargs: Any,
    ) -> VST:
        """Return VectorStore initialized from documents and embeddings."""
        texts = [d.page_content for d in documents]
        metadatas = [d.metadata for d in documents]
        return cls.from_texts(texts, embedding, metadatas=metadatas, **kwargs)
[docs]    @classmethod
    async def afrom_documents(
        cls: Type[VST],
        documents: List[Document],
        embedding: Embeddings,
        **kwargs: Any,
    ) -> VST:


"""Return VectorStore initialized from documents and embeddings."""
        texts = [d.page_content for d in documents]
        metadatas = [d.metadata for d in documents]
        return await cls.afrom_texts(texts, embedding, metadatas=metadatas, **kwargs)
[docs]    @classmethod
    @abstractmethod
    def from_texts(
        cls: Type[VST],
        texts: List[str],
        embedding: Embeddings,
        metadatas: Optional[List[dict]] = None,
        **kwargs: Any,
    ) -> VST:
        """Return VectorStore initialized from texts and embeddings."""
[docs]    @classmethod
    async def afrom_texts(
        cls: Type[VST],
        texts: List[str],
        embedding: Embeddings,
        metadatas: Optional[List[dict]] = None,
        **kwargs: Any,
    ) -> VST:
        """Return VectorStore initialized from texts and embeddings."""
        raise NotImplementedError
[docs]    def as_retriever(self, **kwargs: Any) -> VectorStoreRetriever:
        return VectorStoreRetriever(vectorstore=self, **kwargs)
class VectorStoreRetriever(BaseRetriever, BaseModel):
    vectorstore: VectorStore
    search_type: str = "similarity"
    search_kwargs: dict = Field(default_factory=dict)
    class Config:
        """Configuration for this pydantic object."""
        arbitrary_types_allowed = True
    @root_validator()
    def validate_search_type(cls, values: Dict) -> Dict:
        """Validate search type."""
        if "search_type" in values:
            search_type = values["search_type"]
            if search_type not in ("similarity", "similarity_score_threshold", "mmr"):


raise ValueError(f"search_type of {search_type} not allowed.")
            if search_type == "similarity_score_threshold":
                score_threshold = values["search_kwargs"].get("score_threshold")
                if (score_threshold is None) or (
                    not isinstance(score_threshold, float)
                ):
                    raise ValueError(
                        "`score_threshold` is not specified with a float value(0~1) "
                        "in `search_kwargs`."
                    )
        return values
    def get_relevant_documents(self, query: str) -> List[Document]:
        if self.search_type == "similarity":
            docs = self.vectorstore.similarity_search(query, **self.search_kwargs)
        elif self.search_type == "similarity_score_threshold":
            docs_and_similarities = (
                self.vectorstore.similarity_search_with_relevance_scores(
                    query, **self.search_kwargs
                )
            )
            docs = [doc for doc, _ in docs_and_similarities]
        elif self.search_type == "mmr":
            docs = self.vectorstore.max_marginal_relevance_search(
                query, **self.search_kwargs
            )
        else:
            raise ValueError(f"search_type of {self.search_type} not allowed.")
        return docs
    async def aget_relevant_documents(self, query: str) -> List[Document]:
        if self.search_type == "similarity":
            docs = await self.vectorstore.asimilarity_search(
                query, **self.search_kwargs
            )
        elif self.search_type == "similarity_score_threshold":
            docs_and_similarities = (
                await self.vectorstore.asimilarity_search_with_relevance_scores(
                    query, **self.search_kwargs
                )
            )


docs = [doc for doc, _ in docs_and_similarities]
        elif self.search_type == "mmr":
            docs = await self.vectorstore.amax_marginal_relevance_search(
                query, **self.search_kwargs
            )
        else:
            raise ValueError(f"search_type of {self.search_type} not allowed.")
        return docs
    def add_documents(self, documents: List[Document], **kwargs: Any) -> List[str]:
        """Add documents to vectorstore."""
        return self.vectorstore.add_documents(documents, **kwargs)
    async def aadd_documents(
        self, documents: List[Document], **kwargs: Any
    ) -> List[str]:
        """Add documents to vectorstore."""
        return await self.vectorstore.aadd_documents(documents, **kwargs)
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 04, 2023.


Source code for langchain.vectorstores.lancedb
"""Wrapper around LanceDB vector database"""
from __future__ import annotations
import uuid
from typing import Any, Iterable, List, Optional
from langchain.docstore.document import Document
from langchain.embeddings.base import Embeddings
from langchain.vectorstores.base import VectorStore
[docs]class LanceDB(VectorStore):
    """Wrapper around LanceDB vector database.
    To use, you should have ``lancedb`` python package installed.
    Example:
        .. code-block:: python
            db = lancedb.connect('./lancedb')
            table = db.open_table('my_table')
            vectorstore = LanceDB(table, embedding_function)
            vectorstore.add_texts(['text1', 'text2'])
            result = vectorstore.similarity_search('text1')
    """
    def __init__(
        self,
        connection: Any,
        embedding: Embeddings,
        vector_key: Optional[str] = "vector",
        id_key: Optional[str] = "id",
        text_key: Optional[str] = "text",
    ):
        """Initialize with Lance DB connection"""
        try:
            import lancedb
        except ImportError:
            raise ValueError(
                "Could not import lancedb python package. "
                "Please install it with `pip install lancedb`."
            )
        if not isinstance(connection, lancedb.db.LanceTable):
            raise ValueError(
                "connection should be an instance of lancedb.db.LanceTable, ",
                f"got {type(connection)}",
            )
        self._connection = connection
        self._embedding = embedding
        self._vector_key = vector_key
        self._id_key = id_key
        self._text_key = text_key


[docs]    def add_texts(
        self,
        texts: Iterable[str],
        metadatas: Optional[List[dict]] = None,
        ids: Optional[List[str]] = None,
        **kwargs: Any,
    ) -> List[str]:
        """Turn texts into embedding and add it to the database
        Args:
            texts: Iterable of strings to add to the vectorstore.
            metadatas: Optional list of metadatas associated with the texts.
            ids: Optional list of ids to associate with the texts.
        Returns:
            List of ids of the added texts.
        """
        # Embed texts and create documents
        docs = []
        ids = ids or [str(uuid.uuid4()) for _ in texts]
        embeddings = self._embedding.embed_documents(list(texts))
        for idx, text in enumerate(texts):
            embedding = embeddings[idx]
            metadata = metadatas[idx] if metadatas else {}
            docs.append(
                {
                    self._vector_key: embedding,
                    self._id_key: ids[idx],
                    self._text_key: text,
                    **metadata,
                }
            )
        self._connection.add(docs)
        return ids
[docs]    def similarity_search(
        self, query: str, k: int = 4, **kwargs: Any
    ) -> List[Document]:
        """Return documents most similar to the query
        Args:
            query: String to query the vectorstore with.
            k: Number of documents to return.
        Returns:
            List of documents most similar to the query.
        """
        embedding = self._embedding.embed_query(query)
        docs = self._connection.search(embedding).limit(k).to_df()
        return [
            Document(


page_content=row[self._text_key],
                metadata=row[docs.columns != self._text_key],
            )
            for _, row in docs.iterrows()
        ]
[docs]    @classmethod
    def from_texts(
        cls,
        texts: List[str],
        embedding: Embeddings,
        metadatas: Optional[List[dict]] = None,
        connection: Any = None,
        vector_key: Optional[str] = "vector",
        id_key: Optional[str] = "id",
        text_key: Optional[str] = "text",
        **kwargs: Any,
    ) -> LanceDB:
        instance = LanceDB(
            connection,
            embedding,
            vector_key,
            id_key,
            text_key,
        )
        instance.add_texts(texts, metadatas=metadatas, **kwargs)
        return instance
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 04, 2023.


Source code for langchain.vectorstores.annoy
"""Wrapper around Annoy vector database."""
from __future__ import annotations
import os
import pickle
import uuid
from configparser import ConfigParser
from pathlib import Path
from typing import Any, Callable, Dict, Iterable, List, Optional, Tuple
import numpy as np
from langchain.docstore.base import Docstore
from langchain.docstore.document import Document
from langchain.docstore.in_memory import InMemoryDocstore
from langchain.embeddings.base import Embeddings
from langchain.vectorstores.base import VectorStore
from langchain.vectorstores.utils import maximal_marginal_relevance
INDEX_METRICS = frozenset(["angular", "euclidean", "manhattan", "hamming", "dot"])
DEFAULT_METRIC = "angular"
def dependable_annoy_import() -> Any:
    """Import annoy if available, otherwise raise error."""
    try:
        import annoy
    except ImportError:
        raise ValueError(
            "Could not import annoy python package. "
            "Please install it with `pip install --user annoy` "
        )
    return annoy
[docs]class Annoy(VectorStore):
    """Wrapper around Annoy vector database.
    To use, you should have the ``annoy`` python package installed.
    Example:
        .. code-block:: python
            from langchain import Annoy
            db = Annoy(embedding_function, index, docstore, index_to_docstore_id)
    """
    def __init__(
        self,
        embedding_function: Callable,
        index: Any,
        metric: str,
        docstore: Docstore,
        index_to_docstore_id: Dict[int, str],
    ):
        """Initialize with necessary components."""
        self.embedding_function = embedding_function


self.index = index
        self.metric = metric
        self.docstore = docstore
        self.index_to_docstore_id = index_to_docstore_id
[docs]    def add_texts(
        self,
        texts: Iterable[str],
        metadatas: Optional[List[dict]] = None,
        **kwargs: Any,
    ) -> List[str]:
        raise NotImplementedError(
            "Annoy does not allow to add new data once the index is build."
        )
[docs]    def process_index_results(
        self, idxs: List[int], dists: List[float]
    ) -> List[Tuple[Document, float]]:
        """Turns annoy results into a list of documents and scores.
        Args:
            idxs: List of indices of the documents in the index.
            dists: List of distances of the documents in the index.
        Returns:
            List of Documents and scores.
        """
        docs = []
        for idx, dist in zip(idxs, dists):
            _id = self.index_to_docstore_id[idx]
            doc = self.docstore.search(_id)
            if not isinstance(doc, Document):
                raise ValueError(f"Could not find document for id {_id}, got {doc}")
            docs.append((doc, dist))
        return docs
[docs]    def similarity_search_with_score_by_vector(
        self, embedding: List[float], k: int = 4, search_k: int = -1
    ) -> List[Tuple[Document, float]]:
        """Return docs most similar to query.
        Args:
            query: Text to look up documents similar to.
            k: Number of Documents to return. Defaults to 4.
            search_k: inspect up to search_k nodes which defaults


to n_trees * n if not provided
        Returns:
            List of Documents most similar to the query and score for each
        """
        idxs, dists = self.index.get_nns_by_vector(
            embedding, k, search_k=search_k, include_distances=True
        )
        return self.process_index_results(idxs, dists)
[docs]    def similarity_search_with_score_by_index(
        self, docstore_index: int, k: int = 4, search_k: int = -1
    ) -> List[Tuple[Document, float]]:
        """Return docs most similar to query.
        Args:
            query: Text to look up documents similar to.
            k: Number of Documents to return. Defaults to 4.
            search_k: inspect up to search_k nodes which defaults
                to n_trees * n if not provided
        Returns:
            List of Documents most similar to the query and score for each
        """
        idxs, dists = self.index.get_nns_by_item(
            docstore_index, k, search_k=search_k, include_distances=True
        )
        return self.process_index_results(idxs, dists)
[docs]    def similarity_search_with_score(
        self, query: str, k: int = 4, search_k: int = -1
    ) -> List[Tuple[Document, float]]:
        """Return docs most similar to query.
        Args:
            query: Text to look up documents similar to.
            k: Number of Documents to return. Defaults to 4.
            search_k: inspect up to search_k nodes which defaults
                to n_trees * n if not provided
        Returns:
            List of Documents most similar to the query and score for each
        """
        embedding = self.embedding_function(query)


docs = self.similarity_search_with_score_by_vector(embedding, k, search_k)
        return docs
[docs]    def similarity_search_by_vector(
        self, embedding: List[float], k: int = 4, search_k: int = -1, **kwargs: Any
    ) -> List[Document]:
        """Return docs most similar to embedding vector.
        Args:
            embedding: Embedding to look up documents similar to.
            k: Number of Documents to return. Defaults to 4.
            search_k: inspect up to search_k nodes which defaults
                to n_trees * n if not provided
        Returns:
            List of Documents most similar to the embedding.
        """
        docs_and_scores = self.similarity_search_with_score_by_vector(
            embedding, k, search_k
        )
        return [doc for doc, _ in docs_and_scores]
[docs]    def similarity_search_by_index(
        self, docstore_index: int, k: int = 4, search_k: int = -1, **kwargs: Any
    ) -> List[Document]:
        """Return docs most similar to docstore_index.
        Args:
            docstore_index: Index of document in docstore
            k: Number of Documents to return. Defaults to 4.
            search_k: inspect up to search_k nodes which defaults
                to n_trees * n if not provided
        Returns:
            List of Documents most similar to the embedding.
        """
        docs_and_scores = self.similarity_search_with_score_by_index(
            docstore_index, k, search_k
        )
        return [doc for doc, _ in docs_and_scores]
[docs]    def similarity_search(


self, query: str, k: int = 4, search_k: int = -1, **kwargs: Any
    ) -> List[Document]:
        """Return docs most similar to query.
        Args:
            query: Text to look up documents similar to.
            k: Number of Documents to return. Defaults to 4.
            search_k: inspect up to search_k nodes which defaults
                to n_trees * n if not provided
        Returns:
            List of Documents most similar to the query.
        """
        docs_and_scores = self.similarity_search_with_score(query, k, search_k)
        return [doc for doc, _ in docs_and_scores]
[docs]    def max_marginal_relevance_search_by_vector(
        self,
        embedding: List[float],
        k: int = 4,
        fetch_k: int = 20,
        lambda_mult: float = 0.5,
        **kwargs: Any,
    ) -> List[Document]:
        """Return docs selected using the maximal marginal relevance.
        Maximal marginal relevance optimizes for similarity to query AND diversity
        among selected documents.
        Args:
            embedding: Embedding to look up documents similar to.
            fetch_k: Number of Documents to fetch to pass to MMR algorithm.
            k: Number of Documents to return. Defaults to 4.
            lambda_mult: Number between 0 and 1 that determines the degree
                        of diversity among the results with 0 corresponding
                        to maximum diversity and 1 to minimum diversity.
                        Defaults to 0.5.
        Returns:
            List of Documents selected by maximal marginal relevance.
        """
        idxs = self.index.get_nns_by_vector(
            embedding, fetch_k, search_k=-1, include_distances=False


)
        embeddings = [self.index.get_item_vector(i) for i in idxs]
        mmr_selected = maximal_marginal_relevance(
            np.array([embedding], dtype=np.float32),
            embeddings,
            k=k,
            lambda_mult=lambda_mult,
        )
        # ignore the -1's if not enough docs are returned/indexed
        selected_indices = [idxs[i] for i in mmr_selected if i != -1]
        docs = []
        for i in selected_indices:
            _id = self.index_to_docstore_id[i]
            doc = self.docstore.search(_id)
            if not isinstance(doc, Document):
                raise ValueError(f"Could not find document for id {_id}, got {doc}")
            docs.append(doc)
        return docs
[docs]    def max_marginal_relevance_search(
        self,
        query: str,
        k: int = 4,
        fetch_k: int = 20,
        lambda_mult: float = 0.5,
        **kwargs: Any,
    ) -> List[Document]:
        """Return docs selected using the maximal marginal relevance.
        Maximal marginal relevance optimizes for similarity to query AND diversity
        among selected documents.
        Args:
            query: Text to look up documents similar to.
            k: Number of Documents to return. Defaults to 4.
            fetch_k: Number of Documents to fetch to pass to MMR algorithm.
            lambda_mult: Number between 0 and 1 that determines the degree
                        of diversity among the results with 0 corresponding
                        to maximum diversity and 1 to minimum diversity.
                        Defaults to 0.5.
        Returns:
            List of Documents selected by maximal marginal relevance.
        """


embedding = self.embedding_function(query)
        docs = self.max_marginal_relevance_search_by_vector(
            embedding, k, fetch_k, lambda_mult=lambda_mult
        )
        return docs
    @classmethod
    def __from(
        cls,
        texts: List[str],
        embeddings: List[List[float]],
        embedding: Embeddings,
        metadatas: Optional[List[dict]] = None,
        metric: str = DEFAULT_METRIC,
        trees: int = 100,
        n_jobs: int = -1,
        **kwargs: Any,
    ) -> Annoy:
        if metric not in INDEX_METRICS:
            raise ValueError(
                (
                    f"Unsupported distance metric: {metric}. "
                    f"Expected one of {list(INDEX_METRICS)}"
                )
            )
        annoy = dependable_annoy_import()
        if not embeddings:
            raise ValueError("embeddings must be provided to build AnnoyIndex")
        f = len(embeddings[0])
        index = annoy.AnnoyIndex(f, metric=metric)
        for i, emb in enumerate(embeddings):
            index.add_item(i, emb)
        index.build(trees, n_jobs=n_jobs)
        documents = []
        for i, text in enumerate(texts):
            metadata = metadatas[i] if metadatas else {}
            documents.append(Document(page_content=text, metadata=metadata))
        index_to_id = {i: str(uuid.uuid4()) for i in range(len(documents))}
        docstore = InMemoryDocstore(
            {index_to_id[i]: doc for i, doc in enumerate(documents)}
        )
        return cls(embedding.embed_query, index, metric, docstore, index_to_id)


[docs]    @classmethod
    def from_texts(
        cls,
        texts: List[str],
        embedding: Embeddings,
        metadatas: Optional[List[dict]] = None,
        metric: str = DEFAULT_METRIC,
        trees: int = 100,
        n_jobs: int = -1,
        **kwargs: Any,
    ) -> Annoy:
        """Construct Annoy wrapper from raw documents.
        Args:
            texts: List of documents to index.
            embedding: Embedding function to use.
            metadatas: List of metadata dictionaries to associate with documents.
            metric: Metric to use for indexing. Defaults to "angular".
            trees: Number of trees to use for indexing. Defaults to 100.
            n_jobs: Number of jobs to use for indexing. Defaults to -1.
        This is a user friendly interface that:
            1. Embeds documents.
            2. Creates an in memory docstore
            3. Initializes the Annoy database
        This is intended to be a quick way to get started.
        Example:
            .. code-block:: python
                from langchain import Annoy
                from langchain.embeddings import OpenAIEmbeddings
                embeddings = OpenAIEmbeddings()
                index = Annoy.from_texts(texts, embeddings)
        """
        embeddings = embedding.embed_documents(texts)
        return cls.__from(
            texts, embeddings, embedding, metadatas, metric, trees, n_jobs, **kwargs
        )
[docs]    @classmethod
    def from_embeddings(
        cls,
        text_embeddings: List[Tuple[str, List[float]]],
        embedding: Embeddings,
        metadatas: Optional[List[dict]] = None,


metric: str = DEFAULT_METRIC,
        trees: int = 100,
        n_jobs: int = -1,
        **kwargs: Any,
    ) -> Annoy:
        """Construct Annoy wrapper from embeddings.
        Args:
            text_embeddings: List of tuples of (text, embedding)
            embedding: Embedding function to use.
            metadatas: List of metadata dictionaries to associate with documents.
            metric: Metric to use for indexing. Defaults to "angular".
            trees: Number of trees to use for indexing. Defaults to 100.
            n_jobs: Number of jobs to use for indexing. Defaults to -1
        This is a user friendly interface that:
            1. Creates an in memory docstore with provided embeddings
            2. Initializes the Annoy database
        This is intended to be a quick way to get started.
        Example:
            .. code-block:: python
                from langchain import Annoy
                from langchain.embeddings import OpenAIEmbeddings
                embeddings = OpenAIEmbeddings()
                text_embeddings = embeddings.embed_documents(texts)
                text_embedding_pairs = list(zip(texts, text_embeddings))
                db = Annoy.from_embeddings(text_embedding_pairs, embeddings)
        """
        texts = [t[0] for t in text_embeddings]
        embeddings = [t[1] for t in text_embeddings]
        return cls.__from(
            texts, embeddings, embedding, metadatas, metric, trees, n_jobs, **kwargs
        )
[docs]    def save_local(self, folder_path: str, prefault: bool = False) -> None:
        """Save Annoy index, docstore, and index_to_docstore_id to disk.
        Args:


folder_path: folder path to save index, docstore,
                and index_to_docstore_id to.
            prefault: Whether to pre-load the index into memory.
        """
        path = Path(folder_path)
        os.makedirs(path, exist_ok=True)
        # save index, index config, docstore and index_to_docstore_id
        config_object = ConfigParser()
        config_object["ANNOY"] = {
            "f": self.index.f,
            "metric": self.metric,
        }
        self.index.save(str(path / "index.annoy"), prefault=prefault)
        with open(path / "index.pkl", "wb") as file:
            pickle.dump((self.docstore, self.index_to_docstore_id, config_object), file)
[docs]    @classmethod
    def load_local(
        cls,
        folder_path: str,
        embeddings: Embeddings,
    ) -> Annoy:
        """Load Annoy index, docstore, and index_to_docstore_id to disk.
        Args:
            folder_path: folder path to load index, docstore,
                and index_to_docstore_id from.
            embeddings: Embeddings to use when generating queries.
        """
        path = Path(folder_path)
        # load index separately since it is not picklable
        annoy = dependable_annoy_import()
        # load docstore and index_to_docstore_id
        with open(path / "index.pkl", "rb") as file:
            docstore, index_to_docstore_id, config_object = pickle.load(file)
        f = int(config_object["ANNOY"]["f"])
        metric = config_object["ANNOY"]["metric"]
        index = annoy.AnnoyIndex(f, metric=metric)


index.load(str(path / "index.annoy"))
        return cls(
            embeddings.embed_query, index, metric, docstore, index_to_docstore_id
        )
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 04, 2023.


Source code for langchain.vectorstores.redis
"""Wrapper around Redis vector database."""
from __future__ import annotations
import json
import logging
import uuid
from typing import (
    TYPE_CHECKING,
    Any,
    Callable,
    Dict,
    Iterable,
    List,
    Literal,
    Mapping,
    Optional,
    Tuple,
    Type,
)
import numpy as np
from pydantic import BaseModel, root_validator
from langchain.docstore.document import Document
from langchain.embeddings.base import Embeddings
from langchain.utils import get_from_dict_or_env
from langchain.vectorstores.base import VectorStore, VectorStoreRetriever
logger = logging.getLogger(__name__)
if TYPE_CHECKING:
    from redis.client import Redis as RedisType
    from redis.commands.search.query import Query
# required modules
REDIS_REQUIRED_MODULES = [
    {"name": "search", "ver": 20400},
    {"name": "searchlight", "ver": 20400},
]
# distance mmetrics
REDIS_DISTANCE_METRICS = Literal["COSINE", "IP", "L2"]
def _check_redis_module_exist(client: RedisType, required_modules: List[dict]) -> None:
    """Check if the correct Redis modules are installed."""
    installed_modules = client.module_list()
    installed_modules = {
        module[b"name"].decode("utf-8"): module for module in installed_modules
    }
    for module in required_modules:
        if module["name"] in installed_modules and int(
            installed_modules[module["name"]][b"ver"]
        ) >= int(module["ver"]):
            return
    # otherwise raise error
    error_message = (
        "Redis cannot be used as a vector database without RediSearch >=2.4"


"Please head to https://redis.io/docs/stack/search/quick_start/"
        "to know more about installing the RediSearch module within Redis Stack."
    )
    logging.error(error_message)
    raise ValueError(error_message)
def _check_index_exists(client: RedisType, index_name: str) -> bool:
    """Check if Redis index exists."""
    try:
        client.ft(index_name).info()
    except:  # noqa: E722
        logger.info("Index does not exist")
        return False
    logger.info("Index already exists")
    return True
def _redis_key(prefix: str) -> str:
    """Redis key schema for a given prefix."""
    return f"{prefix}:{uuid.uuid4().hex}"
def _redis_prefix(index_name: str) -> str:
    """Redis key prefix for a given index."""
    return f"doc:{index_name}"
def _default_relevance_score(val: float) -> float:
    return 1 - val
[docs]class Redis(VectorStore):
    """Wrapper around Redis vector database.
    To use, you should have the ``redis`` python package installed.
    Example:
        .. code-block:: python
            from langchain.vectorstores import Redis
            from langchain.embeddings import OpenAIEmbeddings
            embeddings = OpenAIEmbeddings()
            vectorstore = Redis(
                redis_url="redis://username:password@localhost:6379"
                index_name="my-index",
                embedding_function=embeddings.embed_query,
            )
    """
    def __init__(
        self,
        redis_url: str,
        index_name: str,
        embedding_function: Callable,
        content_key: str = "content",
        metadata_key: str = "metadata",


vector_key: str = "content_vector",
        relevance_score_fn: Optional[
            Callable[[float], float]
        ] = _default_relevance_score,
        **kwargs: Any,
    ):
        """Initialize with necessary components."""
        try:
            import redis
        except ImportError:
            raise ValueError(
                "Could not import redis python package. "
                "Please install it with `pip install redis>=4.1.0`."
            )
        self.embedding_function = embedding_function
        self.index_name = index_name
        try:
            # connect to redis from url
            redis_client = redis.from_url(redis_url, **kwargs)
            # check if redis has redisearch module installed
            _check_redis_module_exist(redis_client, REDIS_REQUIRED_MODULES)
        except ValueError as e:
            raise ValueError(f"Redis failed to connect: {e}")
        self.client = redis_client
        self.content_key = content_key
        self.metadata_key = metadata_key
        self.vector_key = vector_key
        self.relevance_score_fn = relevance_score_fn
    def _create_index(
        self, dim: int = 1536, distance_metric: REDIS_DISTANCE_METRICS = "COSINE"
    ) -> None:
        try:
            from redis.commands.search.field import TextField, VectorField
            from redis.commands.search.indexDefinition import IndexDefinition, IndexType
        except ImportError:
            raise ValueError(
                "Could not import redis python package. "
                "Please install it with `pip install redis`."
            )
        # Check if index exists
        if not _check_index_exists(self.client, self.index_name):
            # Define schema
            schema = (
                TextField(name=self.content_key),
                TextField(name=self.metadata_key),
                VectorField(


self.vector_key,
                    "FLAT",
                    {
                        "TYPE": "FLOAT32",
                        "DIM": dim,
                        "DISTANCE_METRIC": distance_metric,
                    },
                ),
            )
            prefix = _redis_prefix(self.index_name)
            # Create Redis Index
            self.client.ft(self.index_name).create_index(
                fields=schema,
                definition=IndexDefinition(prefix=[prefix], index_type=IndexType.HASH),
            )
[docs]    def add_texts(
        self,
        texts: Iterable[str],
        metadatas: Optional[List[dict]] = None,
        embeddings: Optional[List[List[float]]] = None,
        keys: Optional[List[str]] = None,
        batch_size: int = 1000,
        **kwargs: Any,
    ) -> List[str]:
        """Add more texts to the vectorstore.
        Args:
            texts (Iterable[str]): Iterable of strings/text to add to the vectorstore.
            metadatas (Optional[List[dict]], optional): Optional list of metadatas.
                Defaults to None.
            embeddings (Optional[List[List[float]]], optional): Optional pre-generated
                embeddings. Defaults to None.
            keys (Optional[List[str]], optional): Optional key values to use as ids.
                Defaults to None.
            batch_size (int, optional): Batch size to use for writes. Defaults to 1000.
        Returns:
            List[str]: List of ids added to the vectorstore
        """
        ids = []
        prefix = _redis_prefix(self.index_name)
        # Write data to redis
        pipeline = self.client.pipeline(transaction=False)
        for i, text in enumerate(texts):
            # Use provided values by default or fallback


key = keys[i] if keys else _redis_key(prefix)
            metadata = metadatas[i] if metadatas else {}
            embedding = embeddings[i] if embeddings else self.embedding_function(text)
            pipeline.hset(
                key,
                mapping={
                    self.content_key: text,
                    self.vector_key: np.array(embedding, dtype=np.float32).tobytes(),
                    self.metadata_key: json.dumps(metadata),
                },
            )
            ids.append(key)
            # Write batch
            if i % batch_size == 0:
                pipeline.execute()
        # Cleanup final batch
        pipeline.execute()
        return ids
[docs]    def similarity_search(
        self, query: str, k: int = 4, **kwargs: Any
    ) -> List[Document]:
        """
        Returns the most similar indexed documents to the query text.
        Args:
            query (str): The query text for which to find similar documents.
            k (int): The number of documents to return. Default is 4.
        Returns:
            List[Document]: A list of documents that are most similar to the query text.
        """
        docs_and_scores = self.similarity_search_with_score(query, k=k)
        return [doc for doc, _ in docs_and_scores]
[docs]    def similarity_search_limit_score(
        self, query: str, k: int = 4, score_threshold: float = 0.2, **kwargs: Any
    ) -> List[Document]:
        """
        Returns the most similar indexed documents to the query text within the
        score_threshold range.
        Args:
            query (str): The query text for which to find similar documents.


k (int): The number of documents to return. Default is 4.
            score_threshold (float): The minimum matching score required for a document
            to be considered a match. Defaults to 0.2.
            Because the similarity calculation algorithm is based on cosine similarity,
            the smaller the angle, the higher the similarity.
        Returns:
            List[Document]: A list of documents that are most similar to the query text,
            including the match score for each document.
        Note:
            If there are no documents that satisfy the score_threshold value,
            an empty list is returned.
        """
        docs_and_scores = self.similarity_search_with_score(query, k=k)
        return [doc for doc, score in docs_and_scores if score < score_threshold]
    def _prepare_query(self, k: int) -> Query:
        try:
            from redis.commands.search.query import Query
        except ImportError:
            raise ValueError(
                "Could not import redis python package. "
                "Please install it with `pip install redis`."
            )
        # Prepare the Query
        hybrid_fields = "*"
        base_query = (
            f"{hybrid_fields}=>[KNN {k} @{self.vector_key} $vector AS vector_score]"
        )
        return_fields = [self.metadata_key, self.content_key, "vector_score"]
        return (
            Query(base_query)
            .return_fields(*return_fields)
            .sort_by("vector_score")
            .paging(0, k)
            .dialect(2)
        )
[docs]    def similarity_search_with_score(
        self, query: str, k: int = 4
    ) -> List[Tuple[Document, float]]:
        """Return docs most similar to query.


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 and score for each
        """
        # Creates embedding vector from user query
        embedding = self.embedding_function(query)
        # Creates Redis query
        redis_query = self._prepare_query(k)
        params_dict: Mapping[str, str] = {
            "vector": np.array(embedding)  # type: ignore
            .astype(dtype=np.float32)
            .tobytes()
        }
        # Perform vector search
        results = self.client.ft(self.index_name).search(redis_query, params_dict)
        # Prepare document results
        docs = [
            (
                Document(
                    page_content=result.content, metadata=json.loads(result.metadata)
                ),
                float(result.vector_score),
            )
            for result in results.docs
        ]
        return docs
    def _similarity_search_with_relevance_scores(
        self,
        query: str,
        k: int = 4,
        **kwargs: Any,
    ) -> List[Tuple[Document, float]]:
        """Return docs and relevance scores, normalized on a scale from 0 to 1.
        0 is dissimilar, 1 is most similar.
        """
        if self.relevance_score_fn is None:
            raise ValueError(
                "relevance_score_fn must be provided to"
                " Redis constructor to normalize scores"
            )
        docs_and_scores = self.similarity_search_with_score(query, k=k)
        return [(doc, self.relevance_score_fn(score)) for doc, score in docs_and_scores]
[docs]    @classmethod
    def from_texts_return_keys(


cls,
        texts: List[str],
        embedding: Embeddings,
        metadatas: Optional[List[dict]] = None,
        index_name: Optional[str] = None,
        content_key: str = "content",
        metadata_key: str = "metadata",
        vector_key: str = "content_vector",
        distance_metric: REDIS_DISTANCE_METRICS = "COSINE",
        **kwargs: Any,
    ) -> Tuple[Redis, List[str]]:
        """Create a Redis vectorstore from raw documents.
        This is a user-friendly interface that:
            1. Embeds documents.
            2. Creates a new index for the embeddings in Redis.
            3. Adds the documents to the newly created Redis index.
        This is intended to be a quick way to get started.
        Example:
            .. code-block:: python
                from langchain.vectorstores import Redis
                from langchain.embeddings import OpenAIEmbeddings
                embeddings = OpenAIEmbeddings()
                redisearch = RediSearch.from_texts(
                    texts,
                    embeddings,
                    redis_url="redis://username:password@localhost:6379"
                )
        """
        redis_url = get_from_dict_or_env(kwargs, "redis_url", "REDIS_URL")
        if "redis_url" in kwargs:
            kwargs.pop("redis_url")
        # Name of the search index if not given
        if not index_name:
            index_name = uuid.uuid4().hex
        # Create instance
        instance = cls(
            redis_url,
            index_name,
            embedding.embed_query,
            content_key=content_key,
            metadata_key=metadata_key,
            vector_key=vector_key,
            **kwargs,
        )
        # Create embeddings over documents


embeddings = embedding.embed_documents(texts)
        # Create the search index
        instance._create_index(dim=len(embeddings[0]), distance_metric=distance_metric)
        # Add data to Redis
        keys = instance.add_texts(texts, metadatas, embeddings)
        return instance, keys
[docs]    @classmethod
    def from_texts(
        cls: Type[Redis],
        texts: List[str],
        embedding: Embeddings,
        metadatas: Optional[List[dict]] = None,
        index_name: Optional[str] = None,
        content_key: str = "content",
        metadata_key: str = "metadata",
        vector_key: str = "content_vector",
        **kwargs: Any,
    ) -> Redis:
        """Create a Redis vectorstore from raw documents.
        This is a user-friendly interface that:
            1. Embeds documents.
            2. Creates a new index for the embeddings in Redis.
            3. Adds the documents to the newly created Redis index.
        This is intended to be a quick way to get started.
        Example:
            .. code-block:: python
                from langchain.vectorstores import Redis
                from langchain.embeddings import OpenAIEmbeddings
                embeddings = OpenAIEmbeddings()
                redisearch = RediSearch.from_texts(
                    texts,
                    embeddings,
                    redis_url="redis://username:password@localhost:6379"
                )
        """
        instance, _ = cls.from_texts_return_keys(
            texts,
            embedding,
            metadatas=metadatas,
            index_name=index_name,
            content_key=content_key,
            metadata_key=metadata_key,
            vector_key=vector_key,
            **kwargs,
        )
        return instance


[docs]    @staticmethod
    def drop_index(
        index_name: str,
        delete_documents: bool,
        **kwargs: Any,
    ) -> bool:
        """
        Drop a Redis search index.
        Args:
            index_name (str): Name of the index to drop.
            delete_documents (bool): Whether to drop the associated documents.
        Returns:
            bool: Whether or not the drop was successful.
        """
        redis_url = get_from_dict_or_env(kwargs, "redis_url", "REDIS_URL")
        try:
            import redis
        except ImportError:
            raise ValueError(
                "Could not import redis python package. "
                "Please install it with `pip install redis`."
            )
        try:
            # We need to first remove redis_url from kwargs,
            # otherwise passing it to Redis will result in an error.
            if "redis_url" in kwargs:
                kwargs.pop("redis_url")
            client = redis.from_url(url=redis_url, **kwargs)
        except ValueError as e:
            raise ValueError(f"Your redis connected error: {e}")
        # Check if index exists
        try:
            client.ft(index_name).dropindex(delete_documents)
            logger.info("Drop index")
            return True
        except:  # noqa: E722
            # Index not exist
            return False
[docs]    @classmethod
    def from_existing_index(
        cls,
        embedding: Embeddings,
        index_name: str,
        content_key: str = "content",
        metadata_key: str = "metadata",
        vector_key: str = "content_vector",
        **kwargs: Any,
    ) -> Redis:
        """Connect to an existing Redis index."""


redis_url = get_from_dict_or_env(kwargs, "redis_url", "REDIS_URL")
        try:
            import redis
        except ImportError:
            raise ValueError(
                "Could not import redis python package. "
                "Please install it with `pip install redis`."
            )
        try:
            # We need to first remove redis_url from kwargs,
            # otherwise passing it to Redis will result in an error.
            if "redis_url" in kwargs:
                kwargs.pop("redis_url")
            client = redis.from_url(url=redis_url, **kwargs)
            # check if redis has redisearch module installed
            _check_redis_module_exist(client, REDIS_REQUIRED_MODULES)
            # ensure that the index already exists
            assert _check_index_exists(
                client, index_name
            ), f"Index {index_name} does not exist"
        except Exception as e:
            raise ValueError(f"Redis failed to connect: {e}")
        return cls(
            redis_url,
            index_name,
            embedding.embed_query,
            content_key=content_key,
            metadata_key=metadata_key,
            vector_key=vector_key,
            **kwargs,
        )
[docs]    def as_retriever(self, **kwargs: Any) -> RedisVectorStoreRetriever:
        return RedisVectorStoreRetriever(vectorstore=self, **kwargs)
class RedisVectorStoreRetriever(VectorStoreRetriever, BaseModel):
    vectorstore: Redis
    search_type: str = "similarity"
    k: int = 4
    score_threshold: float = 0.4
    class Config:
        """Configuration for this pydantic object."""
        arbitrary_types_allowed = True
    @root_validator()


def validate_search_type(cls, values: Dict) -> Dict:
        """Validate search type."""
        if "search_type" in values:
            search_type = values["search_type"]
            if search_type not in ("similarity", "similarity_limit"):
                raise ValueError(f"search_type of {search_type} not allowed.")
        return values
    def get_relevant_documents(self, query: str) -> List[Document]:
        if self.search_type == "similarity":
            docs = self.vectorstore.similarity_search(query, k=self.k)
        elif self.search_type == "similarity_limit":
            docs = self.vectorstore.similarity_search_limit_score(
                query, k=self.k, score_threshold=self.score_threshold
            )
        else:
            raise ValueError(f"search_type of {self.search_type} not allowed.")
        return docs
    async def aget_relevant_documents(self, query: str) -> List[Document]:
        raise NotImplementedError("RedisVectorStoreRetriever does not support async")
    def add_documents(self, documents: List[Document], **kwargs: Any) -> List[str]:
        """Add documents to vectorstore."""
        return self.vectorstore.add_documents(documents, **kwargs)
    async def aadd_documents(
        self, documents: List[Document], **kwargs: Any
    ) -> List[str]:
        """Add documents to vectorstore."""
        return await self.vectorstore.aadd_documents(documents, **kwargs)
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 04, 2023.


Source code for langchain.vectorstores.supabase
from __future__ import annotations
from itertools import repeat
from typing import (
    TYPE_CHECKING,
    Any,
    Iterable,
    List,
    Optional,
    Tuple,
    Type,
    Union,
)
import numpy as np
from langchain.docstore.document import Document
from langchain.embeddings.base import Embeddings
from langchain.vectorstores.base import VectorStore
from langchain.vectorstores.utils import maximal_marginal_relevance
if TYPE_CHECKING:
    import supabase
[docs]class SupabaseVectorStore(VectorStore):
    """VectorStore for a Supabase postgres database. Assumes you have the `pgvector`
    extension installed and a `match_documents` (or similar) function. For more details:
    https://js.langchain.com/docs/modules/indexes/vector_stores/integrations/supabase
    You can implement your own `match_documents` function in order to limit the search
    space to a subset of documents based on your own authorization or business logic.
    Note that the Supabase Python client does not yet support async operations.
    If you'd like to use `max_marginal_relevance_search`, please review the instructions
    below on modifying the `match_documents` function to return matched embeddings.
    """
    _client: supabase.client.Client
    # This is the embedding function. Don't confuse with the embedding vectors.
    # We should perhaps rename the underlying Embedding base class to EmbeddingFunction
    # or something
    _embedding: Embeddings
    table_name: str
    query_name: str
    def __init__(
        self,
        client: supabase.client.Client,
        embedding: Embeddings,
        table_name: str,


query_name: Union[str, None] = None,
    ) -> None:
        """Initialize with supabase client."""
        try:
            import supabase  # noqa: F401
        except ImportError:
            raise ValueError(
                "Could not import supabase python package. "
                "Please install it with `pip install supabase`."
            )
        self._client = client
        self._embedding: Embeddings = embedding
        self.table_name = table_name or "documents"
        self.query_name = query_name or "match_documents"
[docs]    def add_texts(
        self,
        texts: Iterable[str],
        metadatas: Optional[List[dict[Any, Any]]] = None,
        **kwargs: Any,
    ) -> List[str]:
        docs = self._texts_to_documents(texts, metadatas)
        vectors = self._embedding.embed_documents(list(texts))
        return self.add_vectors(vectors, docs)
[docs]    @classmethod
    def from_texts(
        cls: Type["SupabaseVectorStore"],
        texts: List[str],
        embedding: Embeddings,
        metadatas: Optional[List[dict]] = None,
        client: Optional[supabase.client.Client] = None,
        table_name: Optional[str] = "documents",
        query_name: Union[str, None] = "match_documents",
        **kwargs: Any,
    ) -> "SupabaseVectorStore":
        """Return VectorStore initialized from texts and embeddings."""
        if not client:
            raise ValueError("Supabase client is required.")
        if not table_name:
            raise ValueError("Supabase document table_name is required.")
        embeddings = embedding.embed_documents(texts)


docs = cls._texts_to_documents(texts, metadatas)
        _ids = cls._add_vectors(client, table_name, embeddings, docs)
        return cls(
            client=client,
            embedding=embedding,
            table_name=table_name,
            query_name=query_name,
        )
[docs]    def add_vectors(
        self, vectors: List[List[float]], documents: List[Document]
    ) -> List[str]:
        return self._add_vectors(self._client, self.table_name, vectors, documents)
[docs]    def similarity_search(
        self, query: str, k: int = 4, **kwargs: Any
    ) -> List[Document]:
        vectors = self._embedding.embed_documents([query])
        return self.similarity_search_by_vector(vectors[0], k)
[docs]    def similarity_search_by_vector(
        self, embedding: List[float], k: int = 4, **kwargs: Any
    ) -> List[Document]:
        result = self.similarity_search_by_vector_with_relevance_scores(embedding, k)
        documents = [doc for doc, _ in result]
        return documents
[docs]    def similarity_search_with_relevance_scores(
        self, query: str, k: int = 4, **kwargs: Any
    ) -> List[Tuple[Document, float]]:
        vectors = self._embedding.embed_documents([query])
        return self.similarity_search_by_vector_with_relevance_scores(vectors[0], k)
[docs]    def similarity_search_by_vector_with_relevance_scores(
        self, query: List[float], k: int
    ) -> List[Tuple[Document, float]]:
        match_documents_params = dict(query_embedding=query, match_count=k)


res = self._client.rpc(self.query_name, match_documents_params).execute()
        match_result = [
            (
                Document(
                    metadata=search.get("metadata", {}),  # type: ignore
                    page_content=search.get("content", ""),
                ),
                search.get("similarity", 0.0),
            )
            for search in res.data
            if search.get("content")
        ]
        return match_result
[docs]    def similarity_search_by_vector_returning_embeddings(
        self, query: List[float], k: int
    ) -> List[Tuple[Document, float, np.ndarray[np.float32, Any]]]:
        match_documents_params = dict(query_embedding=query, match_count=k)
        res = self._client.rpc(self.query_name, match_documents_params).execute()
        match_result = [
            (
                Document(
                    metadata=search.get("metadata", {}),  # type: ignore
                    page_content=search.get("content", ""),
                ),
                search.get("similarity", 0.0),
                # Supabase returns a vector type as its string represation (!).
                # This is a hack to convert the string to numpy array.
                np.fromstring(
                    search.get("embedding", "").strip("[]"), np.float32, sep=","
                ),
            )
            for search in res.data
            if search.get("content")
        ]
        return match_result
    @staticmethod
    def _texts_to_documents(
        texts: Iterable[str],
        metadatas: Optional[Iterable[dict[Any, Any]]] = None,
    ) -> List[Document]:
        """Return list of Documents from list of texts and metadatas."""
        if metadatas is None:
            metadatas = repeat({})


docs = [
            Document(page_content=text, metadata=metadata)
            for text, metadata in zip(texts, metadatas)
        ]
        return docs
    @staticmethod
    def _add_vectors(
        client: supabase.client.Client,
        table_name: str,
        vectors: List[List[float]],
        documents: List[Document],
    ) -> List[str]:
        """Add vectors to Supabase table."""
        rows: List[dict[str, Any]] = [
            {
                "content": documents[idx].page_content,
                "embedding": embedding,
                "metadata": documents[idx].metadata,  # type: ignore
            }
            for idx, embedding in enumerate(vectors)
        ]
        # According to the SupabaseVectorStore JS implementation, the best chunk size
        # is 500
        chunk_size = 500
        id_list: List[str] = []
        for i in range(0, len(rows), chunk_size):
            chunk = rows[i : i + chunk_size]
            result = client.from_(table_name).insert(chunk).execute()  # type: ignore
            if len(result.data) == 0:
                raise Exception("Error inserting: No rows added")
            # VectorStore.add_vectors returns ids as strings
            ids = [str(i.get("id")) for i in result.data if i.get("id")]
            id_list.extend(ids)
        return id_list
[docs]    def max_marginal_relevance_search_by_vector(
        self,
        embedding: List[float],
        k: int = 4,
        fetch_k: int = 20,
        lambda_mult: float = 0.5,
        **kwargs: Any,
    ) -> List[Document]:


"""Return docs selected using the maximal marginal relevance.
        Maximal marginal relevance optimizes for similarity to query AND diversity
        among selected documents.
        Args:
            embedding: Embedding to look up documents similar to.
            k: Number of Documents to return. Defaults to 4.
            fetch_k: Number of Documents to fetch to pass to MMR algorithm.
            lambda_mult: Number between 0 and 1 that determines the degree
                        of diversity among the results with 0 corresponding
                        to maximum diversity and 1 to minimum diversity.
                        Defaults to 0.5.
        Returns:
            List of Documents selected by maximal marginal relevance.
        """
        result = self.similarity_search_by_vector_returning_embeddings(
            embedding, fetch_k
        )
        matched_documents = [doc_tuple[0] for doc_tuple in result]
        matched_embeddings = [doc_tuple[2] for doc_tuple in result]
        mmr_selected = maximal_marginal_relevance(
            np.array([embedding], dtype=np.float32),
            matched_embeddings,
            k=k,
            lambda_mult=lambda_mult,
        )
        filtered_documents = [matched_documents[i] for i in mmr_selected]
        return filtered_documents
[docs]    def max_marginal_relevance_search(
        self,
        query: str,
        k: int = 4,
        fetch_k: int = 20,
        lambda_mult: float = 0.5,
        **kwargs: Any,
    ) -> List[Document]:
        """Return docs selected using the maximal marginal relevance.
        Maximal marginal relevance optimizes for similarity to query AND diversity
        among selected documents.
        Args:
            query: Text to look up documents similar to.