if drop_old and isinstance(self.col, Collection):
            self.col.drop()
            self.col = None
        # Initialize the vector store
        self._init()
    def _create_connection_alias(self, connection_args: dict) -> str:
        """Create the connection to the Milvus server."""
        from pymilvus import MilvusException, connections
        # Grab the connection arguments that are used for checking existing connection
        host: str = connection_args.get("host", None)
        port: Union[str, int] = connection_args.get("port", None)
        address: str = connection_args.get("address", None)
        uri: str = connection_args.get("uri", None)
        user = connection_args.get("user", None)
        # Order of use is host/port, uri, address
        if host is not None and port is not None:
            given_address = str(host) + ":" + str(port)
        elif uri is not None:
            given_address = uri.split("https://")[1]
        elif address is not None:
            given_address = address
        else:
            given_address = None
            logger.debug("Missing standard address type for reuse atttempt")
        # User defaults to empty string when getting connection info
        if user is not None:
            tmp_user = user
        else:
            tmp_user = ""
        # If a valid address was given, then check if a connection exists
        if given_address is not None:
            for con in connections.list_connections():
                addr = connections.get_connection_addr(con[0])
                if (
                    con[1]
                    and ("address" in addr)
                    and (addr["address"] == given_address)
                    and ("user" in addr)
                    and (addr["user"] == tmp_user)


and ("user" in addr)
                    and (addr["user"] == tmp_user)
                ):
                    logger.debug("Using previous connection: %s", con[0])
                    return con[0]
        # Generate a new connection if one doesnt exist
        alias = uuid4().hex
        try:
            connections.connect(alias=alias, **connection_args)
            logger.debug("Created new connection using: %s", alias)
            return alias
        except MilvusException as e:
            logger.error("Failed to create new connection using: %s", alias)
            raise e
    def _init(
        self, embeddings: Optional[list] = None, metadatas: Optional[list[dict]] = None
    ) -> None:
        if embeddings is not None:
            self._create_collection(embeddings, metadatas)
        self._extract_fields()
        self._create_index()
        self._create_search_params()
        self._load()
    def _create_collection(
        self, embeddings: list, metadatas: Optional[list[dict]] = None
    ) -> None:
        from pymilvus import (
            Collection,
            CollectionSchema,
            DataType,
            FieldSchema,
            MilvusException,
        )
        from pymilvus.orm.types import infer_dtype_bydata
        # Determine embedding dim
        dim = len(embeddings[0])
        fields = []
        # Determine metadata schema
        if metadatas:
            # Create FieldSchema for each entry in metadata.
            for key, value in metadatas[0].items():
                # Infer the corresponding datatype of the metadata
                dtype = infer_dtype_bydata(value)
                # Datatype isnt compatible
                if dtype == DataType.UNKNOWN or dtype == DataType.NONE:


# Datatype isnt compatible
                if dtype == DataType.UNKNOWN or dtype == DataType.NONE:
                    logger.error(
                        "Failure to create collection, unrecognized dtype for key: %s",
                        key,
                    )
                    raise ValueError(f"Unrecognized datatype for {key}.")
                # Dataype is a string/varchar equivalent
                elif dtype == DataType.VARCHAR:
                    fields.append(FieldSchema(key, DataType.VARCHAR, max_length=65_535))
                else:
                    fields.append(FieldSchema(key, dtype))
        # Create the text field
        fields.append(
            FieldSchema(self._text_field, DataType.VARCHAR, max_length=65_535)
        )
        # Create the primary key field
        fields.append(
            FieldSchema(
                self._primary_field, DataType.INT64, is_primary=True, auto_id=True
            )
        )
        # Create the vector field, supports binary or float vectors
        fields.append(
            FieldSchema(self._vector_field, infer_dtype_bydata(embeddings[0]), dim=dim)
        )
        # Create the schema for the collection
        schema = CollectionSchema(fields)
        # Create the collection
        try:
            self.col = Collection(
                name=self.collection_name,
                schema=schema,
                consistency_level=self.consistency_level,
                using=self.alias,
            )
        except MilvusException as e:
            logger.error(
                "Failed to create collection: %s error: %s", self.collection_name, e
            )
            raise e
    def _extract_fields(self) -> None:
        """Grab the existing fields from the Collection"""
        from pymilvus import Collection
        if isinstance(self.col, Collection):
            schema = self.col.schema
            for x in schema.fields:


schema = self.col.schema
            for x in schema.fields:
                self.fields.append(x.name)
            # Since primary field is auto-id, no need to track it
            self.fields.remove(self._primary_field)
    def _get_index(self) -> Optional[dict[str, Any]]:
        """Return the vector index information if it exists"""
        from pymilvus import Collection
        if isinstance(self.col, Collection):
            for x in self.col.indexes:
                if x.field_name == self._vector_field:
                    return x.to_dict()
        return None
    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 HNSW based one
                if self.index_params is None:
                    self.index_params = {
                        "metric_type": "L2",
                        "index_type": "HNSW",
                        "params": {"M": 8, "efConstruction": 64},
                    }
                try:
                    self.col.create_index(
                        self._vector_field,
                        index_params=self.index_params,
                        using=self.alias,
                    )
                # If default did not work, most likely on Zilliz Cloud
                except MilvusException:
                    # Use AUTOINDEX based index
                    self.index_params = {
                        "metric_type": "L2",
                        "index_type": "AUTOINDEX",
                        "params": {},
                    }
                    self.col.create_index(
                        self._vector_field,
                        index_params=self.index_params,
                        using=self.alias,
                    )
                logger.debug(


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
    def _create_search_params(self) -> None:
        """Generate search params based on the current index type"""
        from pymilvus import Collection
        if isinstance(self.col, Collection) and self.search_params is None:
            index = self._get_index()
            if index is not None:
                index_type: str = index["index_param"]["index_type"]
                metric_type: str = index["index_param"]["metric_type"]
                self.search_params = self.default_search_params[index_type]
                self.search_params["metric_type"] = metric_type
    def _load(self) -> None:
        """Load the collection if available."""
        from pymilvus import Collection
        if isinstance(self.col, Collection) and self._get_index() is not None:
            self.col.load()
[docs]    def add_texts(
        self,
        texts: Iterable[str],
        metadatas: Optional[List[dict]] = None,
        timeout: Optional[int] = None,
        batch_size: int = 1000,
        **kwargs: Any,
    ) -> List[str]:
        """Insert text data into Milvus.
        Inserting data when the collection has not be made yet will result
        in creating a new Collection. The data of the first entity decides
        the schema of the new collection, the dim is extracted from the first
        embedding and the columns are decided by the first metadata dict.


embedding and the columns are decided by the first metadata dict.
        Metada keys will need to be present for all inserted values. At
        the moment there is no None equivalent in Milvus.
        Args:
            texts (Iterable[str]): The texts to embed, it is assumed
                that they all fit in memory.
            metadatas (Optional[List[dict]]): Metadata dicts attached to each of
                the texts. Defaults to None.
            timeout (Optional[int]): Timeout for each batch insert. Defaults
                to None.
            batch_size (int, optional): Batch size to use for insertion.
                Defaults to 1000.
        Raises:
            MilvusException: Failure to add texts
        Returns:
            List[str]: The resulting keys for each inserted element.
        """
        from pymilvus import Collection, MilvusException
        texts = list(texts)
        try:
            embeddings = self.embedding_func.embed_documents(texts)
        except NotImplementedError:
            embeddings = [self.embedding_func.embed_query(x) for x in texts]
        if len(embeddings) == 0:
            logger.debug("Nothing to insert, skipping.")
            return []
        # If the collection hasnt been initialized yet, perform all steps to do so
        if not isinstance(self.col, Collection):
            self._init(embeddings, metadatas)
        # Dict to hold all insert columns
        insert_dict: dict[str, list] = {
            self._text_field: texts,
            self._vector_field: embeddings,
        }
        # Collect the metadata into the insert dict.
        if metadatas is not None:
            for d in metadatas:
                for key, value in d.items():
                    if key in self.fields:


for key, value in d.items():
                    if key in self.fields:
                        insert_dict.setdefault(key, []).append(value)
        # Total insert count
        vectors: list = insert_dict[self._vector_field]
        total_count = len(vectors)
        pks: list[str] = []
        assert isinstance(self.col, Collection)
        for i in range(0, total_count, batch_size):
            # Grab end index
            end = min(i + batch_size, total_count)
            # Convert dict to list of lists batch for insertion
            insert_list = [insert_dict[x][i:end] for x in self.fields]
            # Insert into the collection.
            try:
                res: Collection
                res = self.col.insert(insert_list, timeout=timeout, **kwargs)
                pks.extend(res.primary_keys)
            except MilvusException as e:
                logger.error(
                    "Failed to insert batch starting at entity: %s/%s", i, total_count
                )
                raise e
        return pks
[docs]    def similarity_search(
        self,
        query: str,
        k: int = 4,
        param: Optional[dict] = None,
        expr: Optional[str] = None,
        timeout: Optional[int] = None,
        **kwargs: Any,
    ) -> List[Document]:
        """Perform a similarity search against the query string.
        Args:
            query (str): The text to search.
            k (int, optional): How many results to return. Defaults to 4.
            param (dict, optional): The search params for the index type.
                Defaults to None.
            expr (str, optional): Filtering expression. Defaults to None.


Defaults to None.
            expr (str, optional): Filtering expression. Defaults to None.
            timeout (int, optional): How long to wait before timeout error.
                Defaults to None.
            kwargs: Collection.search() keyword arguments.
        Returns:
            List[Document]: Document results for search.
        """
        if self.col is None:
            logger.debug("No existing collection to search.")
            return []
        res = self.similarity_search_with_score(
            query=query, k=k, param=param, expr=expr, timeout=timeout, **kwargs
        )
        return [doc for doc, _ in res]
[docs]    def similarity_search_by_vector(
        self,
        embedding: List[float],
        k: int = 4,
        param: Optional[dict] = None,
        expr: Optional[str] = None,
        timeout: Optional[int] = None,
        **kwargs: Any,
    ) -> List[Document]:
        """Perform a similarity search against the query string.
        Args:
            embedding (List[float]): The embedding vector to search.
            k (int, optional): How many results to return. Defaults to 4.
            param (dict, optional): The search params for the index type.
                Defaults to None.
            expr (str, optional): Filtering expression. Defaults to None.
            timeout (int, optional): How long to wait before timeout error.
                Defaults to None.
            kwargs: Collection.search() keyword arguments.
        Returns:
            List[Document]: Document results for search.
        """
        if self.col is None:
            logger.debug("No existing collection to search.")
            return []
        res = self.similarity_search_with_score_by_vector(


return []
        res = self.similarity_search_with_score_by_vector(
            embedding=embedding, k=k, param=param, expr=expr, timeout=timeout, **kwargs
        )
        return [doc for doc, _ in res]
[docs]    def similarity_search_with_score(
        self,
        query: str,
        k: int = 4,
        param: Optional[dict] = None,
        expr: Optional[str] = None,
        timeout: Optional[int] = None,
        **kwargs: Any,
    ) -> List[Tuple[Document, float]]:
        """Perform a search on a query string and return results with score.
        For more information about the search parameters, take a look at the pymilvus
        documentation found here:
        https://milvus.io/api-reference/pymilvus/v2.2.6/Collection/search().md
        Args:
            query (str): The text being searched.
            k (int, optional): The amount of results ot return. Defaults to 4.
            param (dict): The search params for the specified index.
                Defaults to None.
            expr (str, optional): Filtering expression. Defaults to None.
            timeout (int, optional): How long to wait before timeout error.
                Defaults to None.
            kwargs: Collection.search() keyword arguments.
        Returns:
            List[float], List[Tuple[Document, any, any]]:
        """
        if self.col is None:
            logger.debug("No existing collection to search.")
            return []
        # Embed the query text.
        embedding = self.embedding_func.embed_query(query)
        res = self.similarity_search_with_score_by_vector(


res = self.similarity_search_with_score_by_vector(
            embedding=embedding, k=k, param=param, expr=expr, timeout=timeout, **kwargs
        )
        return res
[docs]    def similarity_search_with_score_by_vector(
        self,
        embedding: List[float],
        k: int = 4,
        param: Optional[dict] = None,
        expr: Optional[str] = None,
        timeout: Optional[int] = None,
        **kwargs: Any,
    ) -> List[Tuple[Document, float]]:
        """Perform a search on a query string and return results with score.
        For more information about the search parameters, take a look at the pymilvus
        documentation found here:
        https://milvus.io/api-reference/pymilvus/v2.2.6/Collection/search().md
        Args:
            embedding (List[float]): The embedding vector being searched.
            k (int, optional): The amount of results ot return. Defaults to 4.
            param (dict): The search params for the specified index.
                Defaults to None.
            expr (str, optional): Filtering expression. Defaults to None.
            timeout (int, optional): How long to wait before timeout error.
                Defaults to None.
            kwargs: Collection.search() keyword arguments.
        Returns:
            List[Tuple[Document, float]]: Result doc and score.
        """
        if self.col is None:
            logger.debug("No existing collection to search.")
            return []
        if param is None:
            param = self.search_params
        # Determine result metadata fields.
        output_fields = self.fields[:]
        output_fields.remove(self._vector_field)
        # Perform the search.
        res = self.col.search(


# Perform the search.
        res = self.col.search(
            data=[embedding],
            anns_field=self._vector_field,
            param=param,
            limit=k,
            expr=expr,
            output_fields=output_fields,
            timeout=timeout,
            **kwargs,
        )
        # Organize results.
        ret = []
        for result in res[0]:
            meta = {x: result.entity.get(x) for x in output_fields}
            doc = Document(page_content=meta.pop(self._text_field), metadata=meta)
            pair = (doc, result.score)
            ret.append(pair)
        return ret
[docs]    def max_marginal_relevance_search(
        self,
        query: str,
        k: int = 4,
        fetch_k: int = 20,
        lambda_mult: float = 0.5,
        param: Optional[dict] = None,
        expr: Optional[str] = None,
        timeout: Optional[int] = None,
        **kwargs: Any,
    ) -> List[Document]:
        """Perform a search and return results that are reordered by MMR.
        Args:
            query (str): The text being searched.
            k (int, optional): How many results to give. Defaults to 4.
            fetch_k (int, optional): Total results to select k from.
                Defaults to 20.
            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
            param (dict, optional): The search params for the specified index.
                Defaults to None.


Defaults to None.
            expr (str, optional): Filtering expression. Defaults to None.
            timeout (int, optional): How long to wait before timeout error.
                Defaults to None.
            kwargs: Collection.search() keyword arguments.
        Returns:
            List[Document]: Document results for search.
        """
        if self.col is None:
            logger.debug("No existing collection to search.")
            return []
        embedding = self.embedding_func.embed_query(query)
        return self.max_marginal_relevance_search_by_vector(
            embedding=embedding,
            k=k,
            fetch_k=fetch_k,
            lambda_mult=lambda_mult,
            param=param,
            expr=expr,
            timeout=timeout,
            **kwargs,
        )
[docs]    def max_marginal_relevance_search_by_vector(
        self,
        embedding: list[float],
        k: int = 4,
        fetch_k: int = 20,
        lambda_mult: float = 0.5,
        param: Optional[dict] = None,
        expr: Optional[str] = None,
        timeout: Optional[int] = None,
        **kwargs: Any,
    ) -> List[Document]:
        """Perform a search and return results that are reordered by MMR.
        Args:
            embedding (str): The embedding vector being searched.
            k (int, optional): How many results to give. Defaults to 4.
            fetch_k (int, optional): Total results to select k from.
                Defaults to 20.
            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


to maximum diversity and 1 to minimum diversity.
                        Defaults to 0.5
            param (dict, optional): The search params for the specified index.
                Defaults to None.
            expr (str, optional): Filtering expression. Defaults to None.
            timeout (int, optional): How long to wait before timeout error.
                Defaults to None.
            kwargs: Collection.search() keyword arguments.
        Returns:
            List[Document]: Document results for search.
        """
        if self.col is None:
            logger.debug("No existing collection to search.")
            return []
        if param is None:
            param = self.search_params
        # Determine result metadata fields.
        output_fields = self.fields[:]
        output_fields.remove(self._vector_field)
        # Perform the search.
        res = self.col.search(
            data=[embedding],
            anns_field=self._vector_field,
            param=param,
            limit=fetch_k,
            expr=expr,
            output_fields=output_fields,
            timeout=timeout,
            **kwargs,
        )
        # Organize results.
        ids = []
        documents = []
        scores = []
        for result in res[0]:
            meta = {x: result.entity.get(x) for x in output_fields}
            doc = Document(page_content=meta.pop(self._text_field), metadata=meta)
            documents.append(doc)
            scores.append(result.score)
            ids.append(result.id)
        vectors = self.col.query(
            expr=f"{self._primary_field} in {ids}",
            output_fields=[self._primary_field, self._vector_field],
            timeout=timeout,
        )
        # Reorganize the results from query to match search order.


)
        # Reorganize the results from query to match search order.
        vectors = {x[self._primary_field]: x[self._vector_field] for x in vectors}
        ordered_result_embeddings = [vectors[x] for x in ids]
        # Get the new order of results.
        new_ordering = maximal_marginal_relevance(
            np.array(embedding), ordered_result_embeddings, k=k, lambda_mult=lambda_mult
        )
        # Reorder the values and return.
        ret = []
        for x in new_ordering:
            # Function can return -1 index
            if x == -1:
                break
            else:
                ret.append(documents[x])
        return ret
[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] = DEFAULT_MILVUS_CONNECTION,
        consistency_level: str = "Session",
        index_params: Optional[dict] = None,
        search_params: Optional[dict] = None,
        drop_old: bool = False,
        **kwargs: Any,
    ) -> Milvus:
        """Create a Milvus 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".


"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:
            Milvus: Milvus 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 May 28, 2023.


Source code for langchain.vectorstores.chroma
"""Wrapper around ChromaDB embeddings platform."""
from __future__ import annotations
import logging
import uuid
from typing import TYPE_CHECKING, Any, Dict, Iterable, List, Optional, Tuple, Type
import numpy as np
from langchain.docstore.document import Document
from langchain.embeddings.base import Embeddings
from langchain.utils import xor_args
from langchain.vectorstores.base import VectorStore
from langchain.vectorstores.utils import maximal_marginal_relevance
if TYPE_CHECKING:
    import chromadb
    import chromadb.config
logger = logging.getLogger()
DEFAULT_K = 4  # Number of Documents to return.
def _results_to_docs(results: Any) -> List[Document]:
    return [doc for doc, _ in _results_to_docs_and_scores(results)]
def _results_to_docs_and_scores(results: Any) -> List[Tuple[Document, float]]:
    return [
        # TODO: Chroma can do batch querying,
        # we shouldn't hard code to the 1st result
        (Document(page_content=result[0], metadata=result[1] or {}), result[2])
        for result in zip(
            results["documents"][0],
            results["metadatas"][0],
            results["distances"][0],
        )
    ]
[docs]class Chroma(VectorStore):
    """Wrapper around ChromaDB embeddings platform.
    To use, you should have the ``chromadb`` python package installed.
    Example:
        .. code-block:: python
                from langchain.vectorstores import Chroma
                from langchain.embeddings.openai import OpenAIEmbeddings
                embeddings = OpenAIEmbeddings()
                vectorstore = Chroma("langchain_store", embeddings.embed_query)
    """


vectorstore = Chroma("langchain_store", embeddings.embed_query)
    """
    _LANGCHAIN_DEFAULT_COLLECTION_NAME = "langchain"
    def __init__(
        self,
        collection_name: str = _LANGCHAIN_DEFAULT_COLLECTION_NAME,
        embedding_function: Optional[Embeddings] = None,
        persist_directory: Optional[str] = None,
        client_settings: Optional[chromadb.config.Settings] = None,
        collection_metadata: Optional[Dict] = None,
        client: Optional[chromadb.Client] = None,
    ) -> None:
        """Initialize with Chroma client."""
        try:
            import chromadb
            import chromadb.config
        except ImportError:
            raise ValueError(
                "Could not import chromadb python package. "
                "Please install it with `pip install chromadb`."
            )
        if client is not None:
            self._client = client
        else:
            if client_settings:
                self._client_settings = client_settings
            else:
                self._client_settings = chromadb.config.Settings()
                if persist_directory is not None:
                    self._client_settings = chromadb.config.Settings(
                        chroma_db_impl="duckdb+parquet",
                        persist_directory=persist_directory,
                    )
            self._client = chromadb.Client(self._client_settings)
        self._embedding_function = embedding_function
        self._persist_directory = persist_directory
        self._collection = self._client.get_or_create_collection(
            name=collection_name,
            embedding_function=self._embedding_function.embed_documents
            if self._embedding_function is not None
            else None,
            metadata=collection_metadata,
        )
    @xor_args(("query_texts", "query_embeddings"))
    def __query_collection(
        self,


def __query_collection(
        self,
        query_texts: Optional[List[str]] = None,
        query_embeddings: Optional[List[List[float]]] = None,
        n_results: int = 4,
        where: Optional[Dict[str, str]] = None,
        **kwargs: Any,
    ) -> List[Document]:
        """Query the chroma collection."""
        try:
            import chromadb
        except ImportError:
            raise ValueError(
                "Could not import chromadb python package. "
                "Please install it with `pip install chromadb`."
            )
        for i in range(n_results, 0, -1):
            try:
                return self._collection.query(
                    query_texts=query_texts,
                    query_embeddings=query_embeddings,
                    n_results=i,
                    where=where,
                    **kwargs,
                )
            except chromadb.errors.NotEnoughElementsException:
                logger.error(
                    f"Chroma collection {self._collection.name} "
                    f"contains fewer than {i} elements."
                )
        raise chromadb.errors.NotEnoughElementsException(
            f"No documents found for Chroma collection {self._collection.name}"
        )
[docs]    def add_texts(
        self,
        texts: Iterable[str],
        metadatas: Optional[List[dict]] = None,
        ids: Optional[List[str]] = None,
        **kwargs: Any,
    ) -> List[str]:
        """Run more texts through the embeddings and add to the vectorstore.
        Args:
            texts (Iterable[str]): Texts to add to the vectorstore.
            metadatas (Optional[List[dict]], optional): Optional list of metadatas.
            ids (Optional[List[str]], optional): Optional list of IDs.


ids (Optional[List[str]], optional): Optional list of IDs.
        Returns:
            List[str]: List of IDs of the added texts.
        """
        # TODO: Handle the case where the user doesn't provide ids on the Collection
        if ids is None:
            ids = [str(uuid.uuid1()) for _ in texts]
        embeddings = None
        if self._embedding_function is not None:
            embeddings = self._embedding_function.embed_documents(list(texts))
        self._collection.add(
            metadatas=metadatas, embeddings=embeddings, documents=texts, ids=ids
        )
        return ids
[docs]    def similarity_search(
        self,
        query: str,
        k: int = DEFAULT_K,
        filter: Optional[Dict[str, str]] = None,
        **kwargs: Any,
    ) -> List[Document]:
        """Run similarity search with Chroma.
        Args:
            query (str): Query text to search for.
            k (int): Number of results to return. Defaults to 4.
            filter (Optional[Dict[str, str]]): Filter by metadata. Defaults to None.
        Returns:
            List[Document]: List of documents most similar to the query text.
        """
        docs_and_scores = self.similarity_search_with_score(query, k, filter=filter)
        return [doc for doc, _ in docs_and_scores]
[docs]    def similarity_search_by_vector(
        self,
        embedding: List[float],
        k: int = DEFAULT_K,
        filter: Optional[Dict[str, str]] = None,
        **kwargs: Any,
    ) -> List[Document]:
        """Return docs most similar to embedding vector.
        Args:


"""Return docs most similar to embedding vector.
        Args:
            embedding (str): Embedding to look up documents similar to.
            k (int): Number of Documents to return. Defaults to 4.
            filter (Optional[Dict[str, str]]): Filter by metadata. Defaults to None.
        Returns:
            List of Documents most similar to the query vector.
        """
        results = self.__query_collection(
            query_embeddings=embedding, n_results=k, where=filter
        )
        return _results_to_docs(results)
[docs]    def similarity_search_with_score(
        self,
        query: str,
        k: int = DEFAULT_K,
        filter: Optional[Dict[str, str]] = None,
        **kwargs: Any,
    ) -> List[Tuple[Document, float]]:
        """Run similarity search with Chroma with distance.
        Args:
            query (str): Query text to search for.
            k (int): Number of results to return. Defaults to 4.
            filter (Optional[Dict[str, str]]): Filter by metadata. Defaults to None.
        Returns:
            List[Tuple[Document, float]]: List of documents most similar to the query
                text with distance in float.
        """
        if self._embedding_function is None:
            results = self.__query_collection(
                query_texts=[query], n_results=k, where=filter
            )
        else:
            query_embedding = self._embedding_function.embed_query(query)
            results = self.__query_collection(
                query_embeddings=[query_embedding], n_results=k, where=filter
            )
        return _results_to_docs_and_scores(results)
[docs]    def max_marginal_relevance_search_by_vector(
        self,


[docs]    def max_marginal_relevance_search_by_vector(
        self,
        embedding: List[float],
        k: int = DEFAULT_K,
        fetch_k: int = 20,
        lambda_mult: float = 0.5,
        filter: Optional[Dict[str, str]] = None,
        **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.
            filter (Optional[Dict[str, str]]): Filter by metadata. Defaults to None.
        Returns:
            List of Documents selected by maximal marginal relevance.
        """
        results = self.__query_collection(
            query_embeddings=embedding,
            n_results=fetch_k,
            where=filter,
            include=["metadatas", "documents", "distances", "embeddings"],
        )
        mmr_selected = maximal_marginal_relevance(
            np.array(embedding, dtype=np.float32),
            results["embeddings"][0],
            k=k,
            lambda_mult=lambda_mult,
        )
        candidates = _results_to_docs(results)
        selected_results = [r for i, r in enumerate(candidates) if i in mmr_selected]
        return selected_results


return selected_results
[docs]    def max_marginal_relevance_search(
        self,
        query: str,
        k: int = DEFAULT_K,
        fetch_k: int = 20,
        lambda_mult: float = 0.5,
        filter: Optional[Dict[str, str]] = None,
        **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.
            filter (Optional[Dict[str, str]]): Filter by metadata. Defaults to None.
        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, filter=filter
        )
        return docs
[docs]    def delete_collection(self) -> None:
        """Delete the collection."""
        self._client.delete_collection(self._collection.name)
[docs]    def get(self, include: Optional[List[str]] = None) -> Dict[str, Any]:


"""Gets the collection.
        Args:
            include (Optional[List[str]]): List of fields to include from db.
                Defaults to None.
        """
        if include is not None:
            return self._collection.get(include=include)
        else:
            return self._collection.get()
[docs]    def persist(self) -> None:
        """Persist the collection.
        This can be used to explicitly persist the data to disk.
        It will also be called automatically when the object is destroyed.
        """
        if self._persist_directory is None:
            raise ValueError(
                "You must specify a persist_directory on"
                "creation to persist the collection."
            )
        self._client.persist()
[docs]    def update_document(self, document_id: str, document: Document) -> None:
        """Update a document in the collection.
        Args:
            document_id (str): ID of the document to update.
            document (Document): Document to update.
        """
        text = document.page_content
        metadata = document.metadata
        self._collection.update_document(document_id, text, metadata)
[docs]    @classmethod
    def from_texts(
        cls: Type[Chroma],
        texts: List[str],
        embedding: Optional[Embeddings] = None,
        metadatas: Optional[List[dict]] = None,
        ids: Optional[List[str]] = None,
        collection_name: str = _LANGCHAIN_DEFAULT_COLLECTION_NAME,
        persist_directory: Optional[str] = None,
        client_settings: Optional[chromadb.config.Settings] = None,
        client: Optional[chromadb.Client] = None,
        **kwargs: Any,
    ) -> Chroma:
        """Create a Chroma vectorstore from a raw documents.


) -> Chroma:
        """Create a Chroma vectorstore from a raw documents.
        If a persist_directory is specified, the collection will be persisted there.
        Otherwise, the data will be ephemeral in-memory.
        Args:
            texts (List[str]): List of texts to add to the collection.
            collection_name (str): Name of the collection to create.
            persist_directory (Optional[str]): Directory to persist the collection.
            embedding (Optional[Embeddings]): Embedding function. Defaults to None.
            metadatas (Optional[List[dict]]): List of metadatas. Defaults to None.
            ids (Optional[List[str]]): List of document IDs. Defaults to None.
            client_settings (Optional[chromadb.config.Settings]): Chroma client settings
        Returns:
            Chroma: Chroma vectorstore.
        """
        chroma_collection = cls(
            collection_name=collection_name,
            embedding_function=embedding,
            persist_directory=persist_directory,
            client_settings=client_settings,
            client=client,
        )
        chroma_collection.add_texts(texts=texts, metadatas=metadatas, ids=ids)
        return chroma_collection
[docs]    @classmethod
    def from_documents(
        cls: Type[Chroma],
        documents: List[Document],
        embedding: Optional[Embeddings] = None,
        ids: Optional[List[str]] = None,
        collection_name: str = _LANGCHAIN_DEFAULT_COLLECTION_NAME,
        persist_directory: Optional[str] = None,
        client_settings: Optional[chromadb.config.Settings] = None,
        client: Optional[chromadb.Client] = None,  # Add this line
        **kwargs: Any,
    ) -> Chroma:


**kwargs: Any,
    ) -> Chroma:
        """Create a Chroma vectorstore from a list of documents.
        If a persist_directory is specified, the collection will be persisted there.
        Otherwise, the data will be ephemeral in-memory.
        Args:
            collection_name (str): Name of the collection to create.
            persist_directory (Optional[str]): Directory to persist the collection.
            ids (Optional[List[str]]): List of document IDs. Defaults to None.
            documents (List[Document]): List of documents to add to the vectorstore.
            embedding (Optional[Embeddings]): Embedding function. Defaults to None.
            client_settings (Optional[chromadb.config.Settings]): Chroma client settings
        Returns:
            Chroma: Chroma vectorstore.
        """
        texts = [doc.page_content for doc in documents]
        metadatas = [doc.metadata for doc in documents]
        return cls.from_texts(
            texts=texts,
            embedding=embedding,
            metadatas=metadatas,
            ids=ids,
            collection_name=collection_name,
            persist_directory=persist_directory,
            client_settings=client_settings,
            client=client,
        )
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on May 28, 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"


"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,


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


)
        # 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 = []


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(


[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 (


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.
        """


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")


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


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:


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,


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")


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 May 28, 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,


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.")


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


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,


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(


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,


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.
        `max_marginal_relevance_search` requires that `query_name` returns matched
        embeddings alongside the match documents. The following function function
        demonstrates how to do this:
        ```sql
        CREATE FUNCTION match_documents_embeddings(query_embedding vector(1536),
                                                   match_count int)
            RETURNS TABLE(
                id bigint,
                content text,
                metadata jsonb,
                embedding vector(1536),
                similarity float)
            LANGUAGE plpgsql
            AS $$
            # variable_conflict use_column
        BEGIN
            RETURN query
            SELECT
                id,
                content,
                metadata,
                embedding,
                1 -(docstore.embedding <=> query_embedding) AS similarity
            FROM
                docstore
            ORDER BY
                docstore.embedding <=> query_embedding
            LIMIT match_count;
        END;
        $$;```
        """
        embedding = self._embedding.embed_documents([query])


$$;```
        """
        embedding = self._embedding.embed_documents([query])
        docs = self.max_marginal_relevance_search_by_vector(
            embedding[0], k, fetch_k, lambda_mult=lambda_mult
        )
        return docs
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on May 28, 2023.


Source code for langchain.vectorstores.faiss
"""Wrapper around FAISS vector database."""
from __future__ import annotations
import math
import os
import pickle
import uuid
from pathlib import Path
from typing import Any, Callable, Dict, Iterable, List, Optional, Tuple
import numpy as np
from langchain.docstore.base import AddableMixin, 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
def dependable_faiss_import(no_avx2: Optional[bool] = None) -> Any:
    """
    Import faiss if available, otherwise raise error.
    If FAISS_NO_AVX2 environment variable is set, it will be considered
    to load FAISS with no AVX2 optimization.
    Args:
        no_avx2: Load FAISS strictly with no AVX2 optimization
            so that the vectorstore is portable and compatible with other devices.
    """
    if no_avx2 is None and "FAISS_NO_AVX2" in os.environ:
        no_avx2 = bool(os.getenv("FAISS_NO_AVX2"))
    try:
        if no_avx2:
            from faiss import swigfaiss as faiss
        else:
            import faiss
    except ImportError:
        raise ValueError(
            "Could not import faiss python package. "
            "Please install it with `pip install faiss` "
            "or `pip install faiss-cpu` (depending on Python version)."
        )
    return faiss
def _default_relevance_score_fn(score: float) -> float:


return faiss
def _default_relevance_score_fn(score: float) -> float:
    """Return a similarity score on a scale [0, 1]."""
    # The 'correct' relevance function
    # may differ depending on a few things, including:
    # - the distance / similarity metric used by the VectorStore
    # - the scale of your embeddings (OpenAI's are unit normed. Many others are not!)
    # - embedding dimensionality
    # - etc.
    # This function converts the euclidean norm of normalized embeddings
    # (0 is most similar, sqrt(2) most dissimilar)
    # to a similarity function (0 to 1)
    return 1.0 - score / math.sqrt(2)
[docs]class FAISS(VectorStore):
    """Wrapper around FAISS vector database.
    To use, you should have the ``faiss`` python package installed.
    Example:
        .. code-block:: python
            from langchain import FAISS
            faiss = FAISS(embedding_function, index, docstore, index_to_docstore_id)
    """
    def __init__(
        self,
        embedding_function: Callable,
        index: Any,
        docstore: Docstore,
        index_to_docstore_id: Dict[int, str],
        relevance_score_fn: Optional[
            Callable[[float], float]
        ] = _default_relevance_score_fn,
        normalize_L2: bool = False,
    ):
        """Initialize with necessary components."""
        self.embedding_function = embedding_function
        self.index = index
        self.docstore = docstore
        self.index_to_docstore_id = index_to_docstore_id
        self.relevance_score_fn = relevance_score_fn
        self._normalize_L2 = normalize_L2


self._normalize_L2 = normalize_L2
    def __add(
        self,
        texts: Iterable[str],
        embeddings: Iterable[List[float]],
        metadatas: Optional[List[dict]] = None,
        ids: Optional[List[str]] = None,
        **kwargs: Any,
    ) -> List[str]:
        if not isinstance(self.docstore, AddableMixin):
            raise ValueError(
                "If trying to add texts, the underlying docstore should support "
                f"adding items, which {self.docstore} does not"
            )
        documents = []
        for i, text in enumerate(texts):
            metadata = metadatas[i] if metadatas else {}
            documents.append(Document(page_content=text, metadata=metadata))
        if ids is None:
            ids = [str(uuid.uuid4()) for _ in texts]
        # Add to the index, the index_to_id mapping, and the docstore.
        starting_len = len(self.index_to_docstore_id)
        faiss = dependable_faiss_import()
        vector = np.array(embeddings, dtype=np.float32)
        if self._normalize_L2:
            faiss.normalize_L2(vector)
        self.index.add(vector)
        # Get list of index, id, and docs.
        full_info = [(starting_len + i, ids[i], doc) for i, doc in enumerate(documents)]
        # Add information to docstore and index.
        self.docstore.add({_id: doc for _, _id, doc in full_info})
        index_to_id = {index: _id for index, _id, _ in full_info}
        self.index_to_docstore_id.update(index_to_id)
        return [_id for _, _id, _ in full_info]


return [_id for _, _id, _ in full_info]
[docs]    def add_texts(
        self,
        texts: Iterable[str],
        metadatas: Optional[List[dict]] = None,
        ids: Optional[List[str]] = 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.
            ids: Optional list of unique IDs.
        Returns:
            List of ids from adding the texts into the vectorstore.
        """
        if not isinstance(self.docstore, AddableMixin):
            raise ValueError(
                "If trying to add texts, the underlying docstore should support "
                f"adding items, which {self.docstore} does not"
            )
        # Embed and create the documents.
        embeddings = [self.embedding_function(text) for text in texts]
        return self.__add(texts, embeddings, metadatas=metadatas, ids=ids, **kwargs)
[docs]    def add_embeddings(
        self,
        text_embeddings: Iterable[Tuple[str, List[float]]],
        metadatas: Optional[List[dict]] = None,
        ids: Optional[List[str]] = None,
        **kwargs: Any,
    ) -> List[str]:
        """Run more texts through the embeddings and add to the vectorstore.
        Args:
            text_embeddings: Iterable pairs of string and embedding to
                add to the vectorstore.
            metadatas: Optional list of metadatas associated with the texts.
            ids: Optional list of unique IDs.
        Returns:


ids: Optional list of unique IDs.
        Returns:
            List of ids from adding the texts into the vectorstore.
        """
        if not isinstance(self.docstore, AddableMixin):
            raise ValueError(
                "If trying to add texts, the underlying docstore should support "
                f"adding items, which {self.docstore} does not"
            )
        # Embed and create the documents.
        texts = [te[0] for te in text_embeddings]
        embeddings = [te[1] for te in text_embeddings]
        return self.__add(texts, embeddings, metadatas=metadatas, ids=ids, **kwargs)
[docs]    def similarity_search_with_score_by_vector(
        self, embedding: List[float], k: int = 4
    ) -> List[Tuple[Document, float]]:
        """Return docs most similar to query.
        Args:
            embedding: Embedding vector 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
        """
        faiss = dependable_faiss_import()
        vector = np.array([embedding], dtype=np.float32)
        if self._normalize_L2:
            faiss.normalize_L2(vector)
        scores, indices = self.index.search(vector, k)
        docs = []
        for j, i in enumerate(indices[0]):
            if i == -1:
                # This happens when not enough docs are returned.
                continue
            _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}")


raise ValueError(f"Could not find document for id {_id}, got {doc}")
            docs.append((doc, scores[0][j]))
        return docs
[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
        """
        embedding = self.embedding_function(query)
        docs = self.similarity_search_with_score_by_vector(embedding, k)
        return docs
[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 embedding.
        """
        docs_and_scores = self.similarity_search_with_score_by_vector(embedding, k)
        return [doc for doc, _ in docs_and_scores]
[docs]    def similarity_search(
        self, query: str, k: int = 4, **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.
        Returns:
            List of Documents most similar to the query.
        """


Returns:
            List of Documents most similar to the query.
        """
        docs_and_scores = self.similarity_search_with_score(query, 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.
            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 = self.index.search(np.array([embedding], dtype=np.float32), fetch_k)
        # -1 happens when not enough docs are returned.
        embeddings = [self.index.reconstruct(int(i)) for i in indices[0] if i != -1]
        mmr_selected = maximal_marginal_relevance(
            np.array([embedding], dtype=np.float32),
            embeddings,
            k=k,
            lambda_mult=lambda_mult,
        )
        selected_indices = [indices[0][i] for i in mmr_selected]
        docs = []


docs = []
        for i in selected_indices:
            if i == -1:
                # This happens when not enough docs are returned.
                continue
            _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
[docs]    def merge_from(self, target: FAISS) -> None:
        """Merge another FAISS object with the current one.
        Add the target FAISS to the current one.


Add the target FAISS to the current one.
        Args:
            target: FAISS object you wish to merge into the current one
        Returns:
            None.
        """
        if not isinstance(self.docstore, AddableMixin):
            raise ValueError("Cannot merge with this type of docstore")
        # Numerical index for target docs are incremental on existing ones
        starting_len = len(self.index_to_docstore_id)
        # Merge two IndexFlatL2
        self.index.merge_from(target.index)
        # Get id and docs from target FAISS object
        full_info = []
        for i, target_id in target.index_to_docstore_id.items():
            doc = target.docstore.search(target_id)
            if not isinstance(doc, Document):
                raise ValueError("Document should be returned")
            full_info.append((starting_len + i, target_id, doc))
        # Add information to docstore and index_to_docstore_id.
        self.docstore.add({_id: doc for _, _id, doc in full_info})
        index_to_id = {index: _id for index, _id, _ in full_info}
        self.index_to_docstore_id.update(index_to_id)
    @classmethod
    def __from(
        cls,
        texts: List[str],
        embeddings: List[List[float]],
        embedding: Embeddings,
        metadatas: Optional[List[dict]] = None,
        ids: Optional[List[str]] = None,
        normalize_L2: bool = False,
        **kwargs: Any,
    ) -> FAISS:
        faiss = dependable_faiss_import()
        index = faiss.IndexFlatL2(len(embeddings[0]))
        vector = np.array(embeddings, dtype=np.float32)
        if normalize_L2:


vector = np.array(embeddings, dtype=np.float32)
        if normalize_L2:
            faiss.normalize_L2(vector)
        index.add(vector)
        documents = []
        if ids is None:
            ids = [str(uuid.uuid4()) for _ in texts]
        for i, text in enumerate(texts):
            metadata = metadatas[i] if metadatas else {}
            documents.append(Document(page_content=text, metadata=metadata))
        index_to_id = dict(enumerate(ids))
        docstore = InMemoryDocstore(dict(zip(index_to_id.values(), documents)))
        return cls(
            embedding.embed_query,
            index,
            docstore,
            index_to_id,
            normalize_L2=normalize_L2,
            **kwargs,
        )
[docs]    @classmethod
    def from_texts(
        cls,
        texts: List[str],
        embedding: Embeddings,
        metadatas: Optional[List[dict]] = None,
        ids: Optional[List[str]] = None,
        **kwargs: Any,
    ) -> FAISS:
        """Construct FAISS wrapper from raw documents.
        This is a user friendly interface that:
            1. Embeds documents.
            2. Creates an in memory docstore
            3. Initializes the FAISS database
        This is intended to be a quick way to get started.
        Example:
            .. code-block:: python
                from langchain import FAISS
                from langchain.embeddings import OpenAIEmbeddings
                embeddings = OpenAIEmbeddings()
                faiss = FAISS.from_texts(texts, embeddings)
        """
        embeddings = embedding.embed_documents(texts)
        return cls.__from(
            texts,
            embeddings,
            embedding,


return cls.__from(
            texts,
            embeddings,
            embedding,
            metadatas=metadatas,
            ids=ids,
            **kwargs,
        )
[docs]    @classmethod
    def from_embeddings(
        cls,
        text_embeddings: List[Tuple[str, List[float]]],
        embedding: Embeddings,
        metadatas: Optional[List[dict]] = None,
        ids: Optional[List[str]] = None,
        **kwargs: Any,
    ) -> FAISS:
        """Construct FAISS wrapper from raw documents.
        This is a user friendly interface that:
            1. Embeds documents.
            2. Creates an in memory docstore
            3. Initializes the FAISS database
        This is intended to be a quick way to get started.
        Example:
            .. code-block:: python
                from langchain import FAISS
                from langchain.embeddings import OpenAIEmbeddings
                embeddings = OpenAIEmbeddings()
                text_embeddings = embeddings.embed_documents(texts)
                text_embedding_pairs = list(zip(texts, text_embeddings))
                faiss = FAISS.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=metadatas,
            ids=ids,
            **kwargs,
        )
[docs]    def save_local(self, folder_path: str, index_name: str = "index") -> None:
        """Save FAISS index, docstore, and index_to_docstore_id to disk.
        Args:


Args:
            folder_path: folder path to save index, docstore,
                and index_to_docstore_id to.
            index_name: for saving with a specific index file name
        """
        path = Path(folder_path)
        path.mkdir(exist_ok=True, parents=True)
        # save index separately since it is not picklable
        faiss = dependable_faiss_import()
        faiss.write_index(
            self.index, str(path / "{index_name}.faiss".format(index_name=index_name))
        )
        # save docstore and index_to_docstore_id
        with open(path / "{index_name}.pkl".format(index_name=index_name), "wb") as f:
            pickle.dump((self.docstore, self.index_to_docstore_id), f)
[docs]    @classmethod
    def load_local(
        cls, folder_path: str, embeddings: Embeddings, index_name: str = "index"
    ) -> FAISS:
        """Load FAISS 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
            index_name: for saving with a specific index file name
        """
        path = Path(folder_path)
        # load index separately since it is not picklable
        faiss = dependable_faiss_import()
        index = faiss.read_index(
            str(path / "{index_name}.faiss".format(index_name=index_name))
        )
        # load docstore and index_to_docstore_id
        with open(path / "{index_name}.pkl".format(index_name=index_name), "rb") as f:


docstore, index_to_docstore_id = pickle.load(f)
        return cls(embeddings.embed_query, index, docstore, index_to_docstore_id)
    def _similarity_search_with_relevance_scores(
        self,
        query: str,
        k: int = 4,
        **kwargs: Any,
    ) -> List[Tuple[Document, float]]:
        """Return docs and their similarity scores on a scale from 0 to 1."""
        if self.relevance_score_fn is None:
            raise ValueError(
                "normalize_score_fn must be provided to"
                " FAISS 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]
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on May 28, 2023.


Source code for langchain.vectorstores.typesense
"""Wrapper around Typesense vector search"""
from __future__ import annotations
import uuid
from typing import TYPE_CHECKING, Any, Iterable, List, Optional, Tuple, Union
from langchain.docstore.document import Document
from langchain.embeddings.base import Embeddings
from langchain.utils import get_from_env
from langchain.vectorstores.base import VectorStore
if TYPE_CHECKING:
    from typesense.client import Client
    from typesense.collection import Collection
[docs]class Typesense(VectorStore):
    """Wrapper around Typesense vector search.
    To use, you should have the ``typesense`` python package installed.
    Example:
        .. code-block:: python
            from langchain.embedding.openai import OpenAIEmbeddings
            from langchain.vectorstores import Typesense
            import typesense
            node = {
                "host": "localhost",  # For Typesense Cloud use xxx.a1.typesense.net
                "port": "8108",       # For Typesense Cloud use 443
                "protocol": "http"    # For Typesense Cloud use https
            }
            typesense_client = typesense.Client(
                {
                  "nodes": [node],
                  "api_key": "<API_KEY>",
                  "connection_timeout_seconds": 2
                }
            )
            typesense_collection_name = "langchain-memory"
            embedding = OpenAIEmbeddings()
            vectorstore = Typesense(
                typesense_client,
                typesense_collection_name,
                embedding.embed_query,
                "text",
            )
    """
    def __init__(
        self,
        typesense_client: Client,
        embedding: Embeddings,
        *,
        typesense_collection_name: Optional[str] = None,


*,
        typesense_collection_name: Optional[str] = None,
        text_key: str = "text",
    ):
        """Initialize with Typesense client."""
        try:
            from typesense import Client
        except ImportError:
            raise ValueError(
                "Could not import typesense python package. "
                "Please install it with `pip install typesense`."
            )
        if not isinstance(typesense_client, Client):
            raise ValueError(
                f"typesense_client should be an instance of typesense.Client, "
                f"got {type(typesense_client)}"
            )
        self._typesense_client = typesense_client
        self._embedding = embedding
        self._typesense_collection_name = (
            typesense_collection_name or f"langchain-{str(uuid.uuid4())}"
        )
        self._text_key = text_key
    @property
    def _collection(self) -> Collection:
        return self._typesense_client.collections[self._typesense_collection_name]
    def _prep_texts(
        self,
        texts: Iterable[str],
        metadatas: Optional[List[dict]],
        ids: Optional[List[str]],
    ) -> List[dict]:
        """Embed and create the documents"""
        _ids = ids or (str(uuid.uuid4()) for _ in texts)
        _metadatas: Iterable[dict] = metadatas or ({} for _ in texts)
        embedded_texts = self._embedding.embed_documents(list(texts))
        return [
            {"id": _id, "vec": vec, f"{self._text_key}": text, "metadata": metadata}
            for _id, vec, text, metadata in zip(_ids, embedded_texts, texts, _metadatas)
        ]