ޠj+SrSSKJr SSKJrJr SSKJr SSKJ r J r SSK J r SSK JrJrJr SSKJrJr SS KJr SS KJrJrJrJr SS KJr \ (aSS KJrJr \r \!\r"\\ \"4r#\\ \"4r$"S S\SS9r%"SS\\ \"4\5r&g)a5**Retriever** class returns `Document` objects given a text **query**. It is more general than a vector store. A retriever does not need to be able to store documents, only to return (or retrieve) it. Vector stores can be used as the backbone of a retriever, but there are other types of retrievers as well. ) annotations)ABCabstractmethod) signature) TYPE_CHECKINGAny) ConfigDict)Self TypedDictoverride)AsyncCallbackManagerCallbackManager)Document)RunnableRunnableConfigRunnableSerializable ensure_config)run_in_executor)#AsyncCallbackManagerForRetrieverRunCallbackManagerForRetrieverRuncH\rSrSr%SrS\S'S\S'S\S'S\S'S rg ) LangSmithRetrieverParams'z!LangSmith parameters for tracing.strls_retriever_namez str | Nonels_vector_store_providerls_embedding_providerls_embedding_modelN)__name__ __module__ __qualname____firstlineno____doc____annotations____static_attributes__rS/var/www/html/gaurav/venv/lib/python3.13/site-packages/langchain_core/retrievers.pyrr's)+(( %%""r'rF)totalc^\rSrSr%Sr\"SS9rSrS\S'Sr S\S'S r S \S 'S r S \S '\ SU4Sjj5r SSjr\ SSSjj5r\ SSSjj5r\SSj5rSSjrSrU=r$) BaseRetriever7aAbstract base class for a document retrieval system. A retrieval system is defined as something that can take string queries and return the most 'relevant' documents from some source. Usage: A retriever follows the standard `Runnable` interface, and should be used via the standard `Runnable` methods of `invoke`, `ainvoke`, `batch`, `abatch`. Implementation: When implementing a custom retriever, the class should implement the `_get_relevant_documents` method to define the logic for retrieving documents. Optionally, an async native implementations can be provided by overriding the `_aget_relevant_documents` method. !!! example "Retriever that returns the first 5 documents from a list of documents" ```python from langchain_core.documents import Document from langchain_core.retrievers import BaseRetriever class SimpleRetriever(BaseRetriever): docs: list[Document] k: int = 5 def _get_relevant_documents(self, query: str) -> list[Document]: """Return the first k documents from the list of documents""" return self.docs[:self.k] async def _aget_relevant_documents(self, query: str) -> list[Document]: """(Optional) async native implementation.""" return self.docs[:self.k] ``` !!! example "Simple retriever based on a scikit-learn vectorizer" ```python from sklearn.metrics.pairwise import cosine_similarity class TFIDFRetriever(BaseRetriever, BaseModel): vectorizer: Any docs: list[Document] tfidf_array: Any k: int = 4 class Config: arbitrary_types_allowed = True def _get_relevant_documents(self, query: str) -> list[Document]: # Ip -- (n_docs,x), Op -- (n_docs,n_Feats) query_vec = self.vectorizer.transform([query]) # Op -- (n_docs,1) -- Cosine Sim with each doc results = cosine_similarity(self.tfidf_array, query_vec).reshape((-1,)) return [self.docs[i] for i in results.argsort()[-self.k :][::-1]] ``` T)arbitrary_types_allowedFbool_new_arg_supported_expects_other_argsNzlist[str] | Nonetagszdict[str, Any] | Nonemetadatac r>[TU]"S0UD6 [UR5RnUR S5SLUlUR (d/UR[R:XaSSjnX0l[[UR551Sk- 5S:Ul g)N run_managercL# [SURU5IShvN $N7fN)r_get_relevant_documents)selfquerys r(_aget_relevant_documentsABaseRetriever.__init_subclass__.._aget_relevant_documentss#-T43O3OQVWWWWs $"$>r8r9r4rr)r8r r9rreturnlist[Document]) super__init_subclass__rr7 parametersgetr/r:r+lensetkeysr0)clskwargsr@r: __class__s r(r?BaseRetriever.__init_subclass__s !+F+s::;FF !+ !>d!J&&,, 0V0VV X X#& X X ,D ( JOO%&)II JQ N r'c UR5nURS5(aUSSnOURS5(aUSSnUR5n[ US9$)z Get standard params for tracing. Retriever Ni)r)get_name startswithendswithlowerr)r8_kwargsdefault_retriever_names r(_get_ls_paramsBaseRetriever._get_ls_paramsse!% ! , ,[ 9 9%;AB%? " # , ,[ 9 9%;CR%@ "!7!=!=!?':PQQr'c [U5n0URS5=(d 0EUR"S 0UD6En[R"URS5SURSS5URS5UR UUR S9nURSUURS5=(d UR5URS S5S 9nUR(aUO0nUR(aUR"U4S U0UD6nOUR"U40UD6nURU5 U$![an URU 5 eSn A ff=f) aTInvoke the retriever to get relevant documents. Main entry point for synchronous retriever invocations. Args: input: The query string. config: Configuration for the retriever. **kwargs: Additional arguments to pass to the retriever. Returns: List of relevant documents. Examples: ```python retriever.invoke("query") ``` r2 callbacksNverboseFr1rVinheritable_tags local_tagsinheritable_metadatalocal_metadatarun_namerun_idnamer]r4r)rrArRr configurer1r2on_retriever_startrLpopr0r/r7on_retriever_end Exceptionon_retriever_error r8inputconfigrFrZcallback_managerr4kwargs_resultes r(invokeBaseRetriever.invokese*v& zz*%+ !!+F+ +44 JJ{ # JJy%0#ZZ/yy!5== '99  J':4==?::h- :   $ 8 8fbG&&55'26=55eGwG  ( ( M   * *1 -  sAE E" EE"c 4# [U5n0URS5=(d 0EUR"S 0UD6En[R"URS5SURSS5URS5UR UUR S9nURSUURS5=(d UR5URS S5S 9IShvN nUR(aUO0nUR(aUR"U4S U0UD6IShvN nOUR"U40UD6IShvN nURU5IShvN U$NN=N#N ![a n URU 5IShvN eSn A ff=f7f) akAsynchronously invoke the retriever to get relevant documents. Main entry point for asynchronous retriever invocations. Args: input: The query string. config: Configuration for the retriever. **kwargs: Additional arguments to pass to the retriever. Returns: List of relevant documents. Examples: ```python await retriever.ainvoke("query") ``` r2rUNrVFr1rWr\r]r^r4r)rrArRr r`r1r2rarLrbr0r/r:rcrdrerfs r(ainvokeBaseRetriever.ainvokes0v& zz*%+ !!+F+ 099 JJ{ # JJy%0#ZZ/yy!5== -??  J':4==?::h- @    $ 8 8fbG&&#<< '2 6=  $<E+'E%(E+E'E+FE)F%E+'E+)F+ F5F F  FFFcg)zGet documents relevant to a query. Args: query: String to find relevant documents for. run_manager: The callback handler to use. Returns: List of relevant documents. Nrr8r9r4s r(r7%BaseRetriever._get_relevant_documents)sr'cf# [SURUUR5S9IShvN $N7f)zAsynchronously get documents relevant to a query. Args: query: String to find relevant documents for run_manager: The callback handler to use Returns: List of relevant documents N)r4)rr7get_syncrss r(r:&BaseRetriever._aget_relevant_documents7s9%   ( ( #,,.     s (1/1r)rFrr<None)rPrr<rr6)rgrrhzRunnableConfig | NonerFrr<r=)r9rr4rr<r=)r9rr4rr<r=)r r!r"r#r$r model_configr/r%r0r1r2r r?rRrmrprr7r:r& __classcell__)rGs@r(r+r+7s2;z $L %$ %%!D !'+H#*  * R:>77"77JM7 77r)-::&: :  ::x    *H        *M   r'r+N)'r$ __future__rabcrrinspectrtypingrrpydanticr typing_extensionsr r r langchain_core.callbacks.managerr rlangchain_core.documentsrlangchain_core.runnablesrrrrlangchain_core.runnables.configrrrrRetrieverInputlistRetrieverOutput RetrieverLikeRetrieverOutputLikerr+rr'r(rs##%77R- < x.89 sO34 y  Q ()HI3Q r'