__init__.py — langchain Source File

Source Code

"""**Retriever** class returns Documents given a text **query**.

It is more general than a vector store. A retriever does not need to be able to
store documents, only to return (or retrieve) it. Vector stores can be used as
the backbone of a retriever, but there are other types of retrievers as well.
"""

from typing import TYPE_CHECKING, Any

from langchain_classic._api.module_import import create_importer
from langchain_classic.retrievers.contextual_compression import (
    ContextualCompressionRetriever,
)
from langchain_classic.retrievers.ensemble import EnsembleRetriever
from langchain_classic.retrievers.merger_retriever import MergerRetriever
from langchain_classic.retrievers.multi_query import MultiQueryRetriever
from langchain_classic.retrievers.multi_vector import MultiVectorRetriever
from langchain_classic.retrievers.parent_document_retriever import (
    ParentDocumentRetriever,
)
from langchain_classic.retrievers.re_phraser import RePhraseQueryRetriever
from langchain_classic.retrievers.self_query.base import SelfQueryRetriever
from langchain_classic.retrievers.time_weighted_retriever import (
    TimeWeightedVectorStoreRetriever,
)

if TYPE_CHECKING:
    from langchain_community.retrievers import (
        AmazonKendraRetriever,
        AmazonKnowledgeBasesRetriever,
        ArceeRetriever,
        ArxivRetriever,
        AzureAISearchRetriever,
        AzureCognitiveSearchRetriever,
        BM25Retriever,
        ChaindeskRetriever,
        ChatGPTPluginRetriever,
        CohereRagRetriever,
        DocArrayRetriever,
        DriaRetriever,
        ElasticSearchBM25Retriever,
        EmbedchainRetriever,
        GoogleCloudEnterpriseSearchRetriever,
        GoogleDocumentAIWarehouseRetriever,
        GoogleVertexAIMultiTurnSearchRetriever,
        GoogleVertexAISearchRetriever,
        KayAiRetriever,
        KNNRetriever,
        LlamaIndexGraphRetriever,
        LlamaIndexRetriever,
        MetalRetriever,
        MilvusRetriever,
        NeuralDBRetriever,
        OutlineRetriever,
        PineconeHybridSearchRetriever,
        PubMedRetriever,
        RemoteLangChainRetriever,
        SVMRetriever,
        TavilySearchAPIRetriever,
        TFIDFRetriever,
// ... (110 more lines)