Source code for langchain.chains.qa_with_sources.base
"""Question answering with sources over documents."""
from __future__ import annotations
import re
from abc import ABC, abstractmethod
from typing import Any, Dict, List, Optional
from pydantic import Extra, root_validator
from langchain.base_language import BaseLanguageModel
from langchain.callbacks.manager import (
    AsyncCallbackManagerForChainRun,
    CallbackManagerForChainRun,
)
from langchain.chains.base import Chain
from langchain.chains.combine_documents.base import BaseCombineDocumentsChain
from langchain.chains.combine_documents.map_reduce import MapReduceDocumentsChain
from langchain.chains.combine_documents.stuff import StuffDocumentsChain
from langchain.chains.llm import LLMChain
from langchain.chains.qa_with_sources.loading import load_qa_with_sources_chain
from langchain.chains.qa_with_sources.map_reduce_prompt import (
    COMBINE_PROMPT,
    EXAMPLE_PROMPT,
    QUESTION_PROMPT,
)
from langchain.docstore.document import Document
from langchain.prompts.base import BasePromptTemplate
class BaseQAWithSourcesChain(Chain, ABC):
    """Question answering with sources over documents."""
    combine_documents_chain: BaseCombineDocumentsChain
    """Chain to use to combine documents."""
    question_key: str = "question"  #: :meta private:
    input_docs_key: str = "docs"  #: :meta private:
    answer_key: str = "answer"  #: :meta private:
    sources_answer_key: str = "sources"  #: :meta private:
    return_source_documents: bool = False
    """Return the source documents."""
    @classmethod
    def from_llm(
        cls,
        llm: BaseLanguageModel,
        document_prompt: BasePromptTemplate = EXAMPLE_PROMPT,


document_prompt: BasePromptTemplate = EXAMPLE_PROMPT,
        question_prompt: BasePromptTemplate = QUESTION_PROMPT,
        combine_prompt: BasePromptTemplate = COMBINE_PROMPT,
        **kwargs: Any,
    ) -> BaseQAWithSourcesChain:
        """Construct the chain from an LLM."""
        llm_question_chain = LLMChain(llm=llm, prompt=question_prompt)
        llm_combine_chain = LLMChain(llm=llm, prompt=combine_prompt)
        combine_results_chain = StuffDocumentsChain(
            llm_chain=llm_combine_chain,
            document_prompt=document_prompt,
            document_variable_name="summaries",
        )
        combine_document_chain = MapReduceDocumentsChain(
            llm_chain=llm_question_chain,
            combine_document_chain=combine_results_chain,
            document_variable_name="context",
        )
        return cls(
            combine_documents_chain=combine_document_chain,
            **kwargs,
        )
    @classmethod
    def from_chain_type(
        cls,
        llm: BaseLanguageModel,
        chain_type: str = "stuff",
        chain_type_kwargs: Optional[dict] = None,
        **kwargs: Any,
    ) -> BaseQAWithSourcesChain:
        """Load chain from chain type."""
        _chain_kwargs = chain_type_kwargs or {}
        combine_document_chain = load_qa_with_sources_chain(
            llm, chain_type=chain_type, **_chain_kwargs
        )
        return cls(combine_documents_chain=combine_document_chain, **kwargs)
    class Config:
        """Configuration for this pydantic object."""
        extra = Extra.forbid
        arbitrary_types_allowed = True
    @property
    def input_keys(self) -> List[str]:
        """Expect input key.


def input_keys(self) -> List[str]:
        """Expect input key.
        :meta private:
        """
        return [self.question_key]
    @property
    def output_keys(self) -> List[str]:
        """Return output key.
        :meta private:
        """
        _output_keys = [self.answer_key, self.sources_answer_key]
        if self.return_source_documents:
            _output_keys = _output_keys + ["source_documents"]
        return _output_keys
    @root_validator(pre=True)
    def validate_naming(cls, values: Dict) -> Dict:
        """Fix backwards compatability in naming."""
        if "combine_document_chain" in values:
            values["combine_documents_chain"] = values.pop("combine_document_chain")
        return values
    @abstractmethod
    def _get_docs(self, inputs: Dict[str, Any]) -> List[Document]:
        """Get docs to run questioning over."""
    def _call(
        self,
        inputs: Dict[str, Any],
        run_manager: Optional[CallbackManagerForChainRun] = None,
    ) -> Dict[str, str]:
        _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager()
        docs = self._get_docs(inputs)
        answer = self.combine_documents_chain.run(
            input_documents=docs, callbacks=_run_manager.get_child(), **inputs
        )
        if re.search(r"SOURCES:\s", answer):
            answer, sources = re.split(r"SOURCES:\s", answer)
        else:
            sources = ""
        result: Dict[str, Any] = {
            self.answer_key: answer,
            self.sources_answer_key: sources,
        }
        if self.return_source_documents:
            result["source_documents"] = docs


}
        if self.return_source_documents:
            result["source_documents"] = docs
        return result
    @abstractmethod
    async def _aget_docs(self, inputs: Dict[str, Any]) -> List[Document]:
        """Get docs to run questioning over."""
    async def _acall(
        self,
        inputs: Dict[str, Any],
        run_manager: Optional[AsyncCallbackManagerForChainRun] = None,
    ) -> Dict[str, Any]:
        _run_manager = run_manager or AsyncCallbackManagerForChainRun.get_noop_manager()
        docs = await self._aget_docs(inputs)
        answer = await self.combine_documents_chain.arun(
            input_documents=docs, callbacks=_run_manager.get_child(), **inputs
        )
        if re.search(r"SOURCES:\s", answer):
            answer, sources = re.split(r"SOURCES:\s", answer)
        else:
            sources = ""
        result: Dict[str, Any] = {
            self.answer_key: answer,
            self.sources_answer_key: sources,
        }
        if self.return_source_documents:
            result["source_documents"] = docs
        return result
[docs]class QAWithSourcesChain(BaseQAWithSourcesChain):
    """Question answering with sources over documents."""
    input_docs_key: str = "docs"  #: :meta private:
    @property
    def input_keys(self) -> List[str]:
        """Expect input key.
        :meta private:
        """
        return [self.input_docs_key, self.question_key]
    def _get_docs(self, inputs: Dict[str, Any]) -> List[Document]:
        return inputs.pop(self.input_docs_key)
    async def _aget_docs(self, inputs: Dict[str, Any]) -> List[Document]:


return inputs.pop(self.input_docs_key)
    @property
    def _chain_type(self) -> str:
        return "qa_with_sources_chain"
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.chains.qa_with_sources.vector_db
"""Question-answering with sources over a vector database."""
import warnings
from typing import Any, Dict, List
from pydantic import Field, root_validator
from langchain.chains.combine_documents.stuff import StuffDocumentsChain
from langchain.chains.qa_with_sources.base import BaseQAWithSourcesChain
from langchain.docstore.document import Document
from langchain.vectorstores.base import VectorStore
[docs]class VectorDBQAWithSourcesChain(BaseQAWithSourcesChain):
    """Question-answering with sources over a vector database."""
    vectorstore: VectorStore = Field(exclude=True)
    """Vector Database to connect to."""
    k: int = 4
    """Number of results to return from store"""
    reduce_k_below_max_tokens: bool = False
    """Reduce the number of results to return from store based on tokens limit"""
    max_tokens_limit: int = 3375
    """Restrict the docs to return from store based on tokens,
    enforced only for StuffDocumentChain and if reduce_k_below_max_tokens is to true"""
    search_kwargs: Dict[str, Any] = Field(default_factory=dict)
    """Extra search args."""
    def _reduce_tokens_below_limit(self, docs: List[Document]) -> List[Document]:
        num_docs = len(docs)
        if self.reduce_k_below_max_tokens and isinstance(
            self.combine_documents_chain, StuffDocumentsChain
        ):
            tokens = [
                self.combine_documents_chain.llm_chain.llm.get_num_tokens(
                    doc.page_content
                )
                for doc in docs
            ]
            token_count = sum(tokens[:num_docs])
            while token_count > self.max_tokens_limit:
                num_docs -= 1
                token_count -= tokens[num_docs]


num_docs -= 1
                token_count -= tokens[num_docs]
        return docs[:num_docs]
    def _get_docs(self, inputs: Dict[str, Any]) -> List[Document]:
        question = inputs[self.question_key]
        docs = self.vectorstore.similarity_search(
            question, k=self.k, **self.search_kwargs
        )
        return self._reduce_tokens_below_limit(docs)
    async def _aget_docs(self, inputs: Dict[str, Any]) -> List[Document]:
        raise NotImplementedError("VectorDBQAWithSourcesChain does not support async")
    @root_validator()
    def raise_deprecation(cls, values: Dict) -> Dict:
        warnings.warn(
            "`VectorDBQAWithSourcesChain` is deprecated - "
            "please use `from langchain.chains import RetrievalQAWithSourcesChain`"
        )
        return values
    @property
    def _chain_type(self) -> str:
        return "vector_db_qa_with_sources_chain"
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.chains.qa_with_sources.retrieval
"""Question-answering with sources over an index."""
from typing import Any, Dict, List
from pydantic import Field
from langchain.chains.combine_documents.stuff import StuffDocumentsChain
from langchain.chains.qa_with_sources.base import BaseQAWithSourcesChain
from langchain.docstore.document import Document
from langchain.schema import BaseRetriever
[docs]class RetrievalQAWithSourcesChain(BaseQAWithSourcesChain):
    """Question-answering with sources over an index."""
    retriever: BaseRetriever = Field(exclude=True)
    """Index to connect to."""
    reduce_k_below_max_tokens: bool = False
    """Reduce the number of results to return from store based on tokens limit"""
    max_tokens_limit: int = 3375
    """Restrict the docs to return from store based on tokens,
    enforced only for StuffDocumentChain and if reduce_k_below_max_tokens is to true"""
    def _reduce_tokens_below_limit(self, docs: List[Document]) -> List[Document]:
        num_docs = len(docs)
        if self.reduce_k_below_max_tokens and isinstance(
            self.combine_documents_chain, StuffDocumentsChain
        ):
            tokens = [
                self.combine_documents_chain.llm_chain.llm.get_num_tokens(
                    doc.page_content
                )
                for doc in docs
            ]
            token_count = sum(tokens[:num_docs])
            while token_count > self.max_tokens_limit:
                num_docs -= 1
                token_count -= tokens[num_docs]
        return docs[:num_docs]
    def _get_docs(self, inputs: Dict[str, Any]) -> List[Document]:
        question = inputs[self.question_key]
        docs = self.retriever.get_relevant_documents(question)


docs = self.retriever.get_relevant_documents(question)
        return self._reduce_tokens_below_limit(docs)
    async def _aget_docs(self, inputs: Dict[str, Any]) -> List[Document]:
        question = inputs[self.question_key]
        docs = await self.retriever.aget_relevant_documents(question)
        return self._reduce_tokens_below_limit(docs)
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.chains.llm_math.base
"""Chain that interprets a prompt and executes python code to do math."""
from __future__ import annotations
import math
import re
import warnings
from typing import Any, Dict, List, Optional
import numexpr
from pydantic import Extra, root_validator
from langchain.base_language import BaseLanguageModel
from langchain.callbacks.manager import (
    AsyncCallbackManagerForChainRun,
    CallbackManagerForChainRun,
)
from langchain.chains.base import Chain
from langchain.chains.llm import LLMChain
from langchain.chains.llm_math.prompt import PROMPT
from langchain.prompts.base import BasePromptTemplate
[docs]class LLMMathChain(Chain):
    """Chain that interprets a prompt and executes python code to do math.
    Example:
        .. code-block:: python
            from langchain import LLMMathChain, OpenAI
            llm_math = LLMMathChain.from_llm(OpenAI())
    """
    llm_chain: LLMChain
    llm: Optional[BaseLanguageModel] = None
    """[Deprecated] LLM wrapper to use."""
    prompt: BasePromptTemplate = PROMPT
    """[Deprecated] Prompt to use to translate to python if necessary."""
    input_key: str = "question"  #: :meta private:
    output_key: str = "answer"  #: :meta private:
    class Config:
        """Configuration for this pydantic object."""
        extra = Extra.forbid
        arbitrary_types_allowed = True
    @root_validator(pre=True)
    def raise_deprecation(cls, values: Dict) -> Dict:
        if "llm" in values:
            warnings.warn(


if "llm" in values:
            warnings.warn(
                "Directly instantiating an LLMMathChain with an llm is deprecated. "
                "Please instantiate with llm_chain argument or using the from_llm "
                "class method."
            )
            if "llm_chain" not in values and values["llm"] is not None:
                prompt = values.get("prompt", PROMPT)
                values["llm_chain"] = LLMChain(llm=values["llm"], prompt=prompt)
        return values
    @property
    def input_keys(self) -> List[str]:
        """Expect input key.
        :meta private:
        """
        return [self.input_key]
    @property
    def output_keys(self) -> List[str]:
        """Expect output key.
        :meta private:
        """
        return [self.output_key]
    def _evaluate_expression(self, expression: str) -> str:
        try:
            local_dict = {"pi": math.pi, "e": math.e}
            output = str(
                numexpr.evaluate(
                    expression.strip(),
                    global_dict={},  # restrict access to globals
                    local_dict=local_dict,  # add common mathematical functions
                )
            )
        except Exception as e:
            raise ValueError(
                f'LLMMathChain._evaluate("{expression}") raised error: {e}.'
                " Please try again with a valid numerical expression"
            )
        # Remove any leading and trailing brackets from the output
        return re.sub(r"^\[|\]$", "", output)
    def _process_llm_result(
        self, llm_output: str, run_manager: CallbackManagerForChainRun
    ) -> Dict[str, str]:


) -> Dict[str, str]:
        run_manager.on_text(llm_output, color="green", verbose=self.verbose)
        llm_output = llm_output.strip()
        text_match = re.search(r"^```text(.*?)```", llm_output, re.DOTALL)
        if text_match:
            expression = text_match.group(1)
            output = self._evaluate_expression(expression)
            run_manager.on_text("\nAnswer: ", verbose=self.verbose)
            run_manager.on_text(output, color="yellow", verbose=self.verbose)
            answer = "Answer: " + output
        elif llm_output.startswith("Answer:"):
            answer = llm_output
        elif "Answer:" in llm_output:
            answer = "Answer: " + llm_output.split("Answer:")[-1]
        else:
            raise ValueError(f"unknown format from LLM: {llm_output}")
        return {self.output_key: answer}
    async def _aprocess_llm_result(
        self,
        llm_output: str,
        run_manager: AsyncCallbackManagerForChainRun,
    ) -> Dict[str, str]:
        await run_manager.on_text(llm_output, color="green", verbose=self.verbose)
        llm_output = llm_output.strip()
        text_match = re.search(r"^```text(.*?)```", llm_output, re.DOTALL)
        if text_match:
            expression = text_match.group(1)
            output = self._evaluate_expression(expression)
            await run_manager.on_text("\nAnswer: ", verbose=self.verbose)
            await run_manager.on_text(output, color="yellow", verbose=self.verbose)
            answer = "Answer: " + output
        elif llm_output.startswith("Answer:"):
            answer = llm_output


elif llm_output.startswith("Answer:"):
            answer = llm_output
        elif "Answer:" in llm_output:
            answer = "Answer: " + llm_output.split("Answer:")[-1]
        else:
            raise ValueError(f"unknown format from LLM: {llm_output}")
        return {self.output_key: answer}
    def _call(
        self,
        inputs: Dict[str, str],
        run_manager: Optional[CallbackManagerForChainRun] = None,
    ) -> Dict[str, str]:
        _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager()
        _run_manager.on_text(inputs[self.input_key])
        llm_output = self.llm_chain.predict(
            question=inputs[self.input_key],
            stop=["```output"],
            callbacks=_run_manager.get_child(),
        )
        return self._process_llm_result(llm_output, _run_manager)
    async def _acall(
        self,
        inputs: Dict[str, str],
        run_manager: Optional[AsyncCallbackManagerForChainRun] = None,
    ) -> Dict[str, str]:
        _run_manager = run_manager or AsyncCallbackManagerForChainRun.get_noop_manager()
        await _run_manager.on_text(inputs[self.input_key])
        llm_output = await self.llm_chain.apredict(
            question=inputs[self.input_key],
            stop=["```output"],
            callbacks=_run_manager.get_child(),
        )
        return await self._aprocess_llm_result(llm_output, _run_manager)
    @property
    def _chain_type(self) -> str:
        return "llm_math_chain"
[docs]    @classmethod
    def from_llm(
        cls,


[docs]    @classmethod
    def from_llm(
        cls,
        llm: BaseLanguageModel,
        prompt: BasePromptTemplate = PROMPT,
        **kwargs: Any,
    ) -> LLMMathChain:
        llm_chain = LLMChain(llm=llm, prompt=prompt)
        return cls(llm_chain=llm_chain, **kwargs)
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.chains.retrieval_qa.base
"""Chain for question-answering against a vector database."""
from __future__ import annotations
import warnings
from abc import abstractmethod
from typing import Any, Dict, List, Optional
from pydantic import Extra, Field, root_validator
from langchain.base_language import BaseLanguageModel
from langchain.callbacks.manager import (
    AsyncCallbackManagerForChainRun,
    CallbackManagerForChainRun,
)
from langchain.chains.base import Chain
from langchain.chains.combine_documents.base import BaseCombineDocumentsChain
from langchain.chains.combine_documents.stuff import StuffDocumentsChain
from langchain.chains.llm import LLMChain
from langchain.chains.question_answering import load_qa_chain
from langchain.chains.question_answering.stuff_prompt import PROMPT_SELECTOR
from langchain.prompts import PromptTemplate
from langchain.schema import BaseRetriever, Document
from langchain.vectorstores.base import VectorStore
class BaseRetrievalQA(Chain):
    combine_documents_chain: BaseCombineDocumentsChain
    """Chain to use to combine the documents."""
    input_key: str = "query"  #: :meta private:
    output_key: str = "result"  #: :meta private:
    return_source_documents: bool = False
    """Return the source documents."""
    class Config:
        """Configuration for this pydantic object."""
        extra = Extra.forbid
        arbitrary_types_allowed = True
        allow_population_by_field_name = True
    @property
    def input_keys(self) -> List[str]:
        """Return the input keys.
        :meta private:
        """
        return [self.input_key]
    @property
    def output_keys(self) -> List[str]:
        """Return the output keys.


def output_keys(self) -> List[str]:
        """Return the output keys.
        :meta private:
        """
        _output_keys = [self.output_key]
        if self.return_source_documents:
            _output_keys = _output_keys + ["source_documents"]
        return _output_keys
    @classmethod
    def from_llm(
        cls,
        llm: BaseLanguageModel,
        prompt: Optional[PromptTemplate] = None,
        **kwargs: Any,
    ) -> BaseRetrievalQA:
        """Initialize from LLM."""
        _prompt = prompt or PROMPT_SELECTOR.get_prompt(llm)
        llm_chain = LLMChain(llm=llm, prompt=_prompt)
        document_prompt = PromptTemplate(
            input_variables=["page_content"], template="Context:\n{page_content}"
        )
        combine_documents_chain = StuffDocumentsChain(
            llm_chain=llm_chain,
            document_variable_name="context",
            document_prompt=document_prompt,
        )
        return cls(combine_documents_chain=combine_documents_chain, **kwargs)
    @classmethod
    def from_chain_type(
        cls,
        llm: BaseLanguageModel,
        chain_type: str = "stuff",
        chain_type_kwargs: Optional[dict] = None,
        **kwargs: Any,
    ) -> BaseRetrievalQA:
        """Load chain from chain type."""
        _chain_type_kwargs = chain_type_kwargs or {}
        combine_documents_chain = load_qa_chain(
            llm, chain_type=chain_type, **_chain_type_kwargs
        )
        return cls(combine_documents_chain=combine_documents_chain, **kwargs)
    @abstractmethod
    def _get_docs(self, question: str) -> List[Document]:


def _get_docs(self, question: str) -> List[Document]:
        """Get documents to do question answering over."""
    def _call(
        self,
        inputs: Dict[str, Any],
        run_manager: Optional[CallbackManagerForChainRun] = None,
    ) -> Dict[str, Any]:
        """Run get_relevant_text and llm on input query.
        If chain has 'return_source_documents' as 'True', returns
        the retrieved documents as well under the key 'source_documents'.
        Example:
        .. code-block:: python
        res = indexqa({'query': 'This is my query'})
        answer, docs = res['result'], res['source_documents']
        """
        _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager()
        question = inputs[self.input_key]
        docs = self._get_docs(question)
        answer = self.combine_documents_chain.run(
            input_documents=docs, question=question, callbacks=_run_manager.get_child()
        )
        if self.return_source_documents:
            return {self.output_key: answer, "source_documents": docs}
        else:
            return {self.output_key: answer}
    @abstractmethod
    async def _aget_docs(self, question: str) -> List[Document]:
        """Get documents to do question answering over."""
    async def _acall(
        self,
        inputs: Dict[str, Any],
        run_manager: Optional[AsyncCallbackManagerForChainRun] = None,
    ) -> Dict[str, Any]:
        """Run get_relevant_text and llm on input query.
        If chain has 'return_source_documents' as 'True', returns
        the retrieved documents as well under the key 'source_documents'.
        Example:


the retrieved documents as well under the key 'source_documents'.
        Example:
        .. code-block:: python
        res = indexqa({'query': 'This is my query'})
        answer, docs = res['result'], res['source_documents']
        """
        _run_manager = run_manager or AsyncCallbackManagerForChainRun.get_noop_manager()
        question = inputs[self.input_key]
        docs = await self._aget_docs(question)
        answer = await self.combine_documents_chain.arun(
            input_documents=docs, question=question, callbacks=_run_manager.get_child()
        )
        if self.return_source_documents:
            return {self.output_key: answer, "source_documents": docs}
        else:
            return {self.output_key: answer}
[docs]class RetrievalQA(BaseRetrievalQA):
    """Chain for question-answering against an index.
    Example:
        .. code-block:: python
            from langchain.llms import OpenAI
            from langchain.chains import RetrievalQA
            from langchain.faiss import FAISS
            from langchain.vectorstores.base import VectorStoreRetriever
            retriever = VectorStoreRetriever(vectorstore=FAISS(...))
            retrievalQA = RetrievalQA.from_llm(llm=OpenAI(), retriever=retriever)
    """
    retriever: BaseRetriever = Field(exclude=True)
    def _get_docs(self, question: str) -> List[Document]:
        return self.retriever.get_relevant_documents(question)
    async def _aget_docs(self, question: str) -> List[Document]:
        return await self.retriever.aget_relevant_documents(question)
    @property
    def _chain_type(self) -> str:
        """Return the chain type."""


def _chain_type(self) -> str:
        """Return the chain type."""
        return "retrieval_qa"
[docs]class VectorDBQA(BaseRetrievalQA):
    """Chain for question-answering against a vector database."""
    vectorstore: VectorStore = Field(exclude=True, alias="vectorstore")
    """Vector Database to connect to."""
    k: int = 4
    """Number of documents to query for."""
    search_type: str = "similarity"
    """Search type to use over vectorstore. `similarity` or `mmr`."""
    search_kwargs: Dict[str, Any] = Field(default_factory=dict)
    """Extra search args."""
    @root_validator()
    def raise_deprecation(cls, values: Dict) -> Dict:
        warnings.warn(
            "`VectorDBQA` is deprecated - "
            "please use `from langchain.chains import RetrievalQA`"
        )
        return values
    @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", "mmr"):
                raise ValueError(f"search_type of {search_type} not allowed.")
        return values
    def _get_docs(self, question: str) -> List[Document]:
        if self.search_type == "similarity":
            docs = self.vectorstore.similarity_search(
                question, k=self.k, **self.search_kwargs
            )
        elif self.search_type == "mmr":
            docs = self.vectorstore.max_marginal_relevance_search(
                question, k=self.k, **self.search_kwargs
            )


question, k=self.k, **self.search_kwargs
            )
        else:
            raise ValueError(f"search_type of {self.search_type} not allowed.")
        return docs
    async def _aget_docs(self, question: str) -> List[Document]:
        raise NotImplementedError("VectorDBQA does not support async")
    @property
    def _chain_type(self) -> str:
        """Return the chain type."""
        return "vector_db_qa"
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.chains.conversation.base
"""Chain that carries on a conversation and calls an LLM."""
from typing import Dict, List
from pydantic import Extra, Field, root_validator
from langchain.chains.conversation.prompt import PROMPT
from langchain.chains.llm import LLMChain
from langchain.memory.buffer import ConversationBufferMemory
from langchain.prompts.base import BasePromptTemplate
from langchain.schema import BaseMemory
[docs]class ConversationChain(LLMChain):
    """Chain to have a conversation and load context from memory.
    Example:
        .. code-block:: python
            from langchain import ConversationChain, OpenAI
            conversation = ConversationChain(llm=OpenAI())
    """
    memory: BaseMemory = Field(default_factory=ConversationBufferMemory)
    """Default memory store."""
    prompt: BasePromptTemplate = PROMPT
    """Default conversation prompt to use."""
    input_key: str = "input"  #: :meta private:
    output_key: str = "response"  #: :meta private:
    class Config:
        """Configuration for this pydantic object."""
        extra = Extra.forbid
        arbitrary_types_allowed = True
    @property
    def input_keys(self) -> List[str]:
        """Use this since so some prompt vars come from history."""
        return [self.input_key]
    @root_validator()
    def validate_prompt_input_variables(cls, values: Dict) -> Dict:
        """Validate that prompt input variables are consistent."""
        memory_keys = values["memory"].memory_variables
        input_key = values["input_key"]
        if input_key in memory_keys:
            raise ValueError(
                f"The input key {input_key} was also found in the memory keys "


f"The input key {input_key} was also found in the memory keys "
                f"({memory_keys}) - please provide keys that don't overlap."
            )
        prompt_variables = values["prompt"].input_variables
        expected_keys = memory_keys + [input_key]
        if set(expected_keys) != set(prompt_variables):
            raise ValueError(
                "Got unexpected prompt input variables. The prompt expects "
                f"{prompt_variables}, but got {memory_keys} as inputs from "
                f"memory, and {input_key} as the normal input key."
            )
        return values
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.chains.api.base
"""Chain that makes API calls and summarizes the responses to answer a question."""
from __future__ import annotations
from typing import Any, Dict, List, Optional
from pydantic import Field, root_validator
from langchain.base_language import BaseLanguageModel
from langchain.callbacks.manager import (
    AsyncCallbackManagerForChainRun,
    CallbackManagerForChainRun,
)
from langchain.chains.api.prompt import API_RESPONSE_PROMPT, API_URL_PROMPT
from langchain.chains.base import Chain
from langchain.chains.llm import LLMChain
from langchain.prompts import BasePromptTemplate
from langchain.requests import TextRequestsWrapper
[docs]class APIChain(Chain):
    """Chain that makes API calls and summarizes the responses to answer a question."""
    api_request_chain: LLMChain
    api_answer_chain: LLMChain
    requests_wrapper: TextRequestsWrapper = Field(exclude=True)
    api_docs: str
    question_key: str = "question"  #: :meta private:
    output_key: str = "output"  #: :meta private:
    @property
    def input_keys(self) -> List[str]:
        """Expect input key.
        :meta private:
        """
        return [self.question_key]
    @property
    def output_keys(self) -> List[str]:
        """Expect output key.
        :meta private:
        """
        return [self.output_key]
    @root_validator(pre=True)
    def validate_api_request_prompt(cls, values: Dict) -> Dict:
        """Check that api request prompt expects the right variables."""
        input_vars = values["api_request_chain"].prompt.input_variables
        expected_vars = {"question", "api_docs"}
        if set(input_vars) != expected_vars:


if set(input_vars) != expected_vars:
            raise ValueError(
                f"Input variables should be {expected_vars}, got {input_vars}"
            )
        return values
    @root_validator(pre=True)
    def validate_api_answer_prompt(cls, values: Dict) -> Dict:
        """Check that api answer prompt expects the right variables."""
        input_vars = values["api_answer_chain"].prompt.input_variables
        expected_vars = {"question", "api_docs", "api_url", "api_response"}
        if set(input_vars) != expected_vars:
            raise ValueError(
                f"Input variables should be {expected_vars}, got {input_vars}"
            )
        return values
    def _call(
        self,
        inputs: Dict[str, Any],
        run_manager: Optional[CallbackManagerForChainRun] = None,
    ) -> Dict[str, str]:
        _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager()
        question = inputs[self.question_key]
        api_url = self.api_request_chain.predict(
            question=question,
            api_docs=self.api_docs,
            callbacks=_run_manager.get_child(),
        )
        _run_manager.on_text(api_url, color="green", end="\n", verbose=self.verbose)
        api_url = api_url.strip()
        api_response = self.requests_wrapper.get(api_url)
        _run_manager.on_text(
            api_response, color="yellow", end="\n", verbose=self.verbose
        )
        answer = self.api_answer_chain.predict(
            question=question,
            api_docs=self.api_docs,
            api_url=api_url,
            api_response=api_response,
            callbacks=_run_manager.get_child(),
        )
        return {self.output_key: answer}
    async def _acall(


return {self.output_key: answer}
    async def _acall(
        self,
        inputs: Dict[str, Any],
        run_manager: Optional[AsyncCallbackManagerForChainRun] = None,
    ) -> Dict[str, str]:
        _run_manager = run_manager or AsyncCallbackManagerForChainRun.get_noop_manager()
        question = inputs[self.question_key]
        api_url = await self.api_request_chain.apredict(
            question=question,
            api_docs=self.api_docs,
            callbacks=_run_manager.get_child(),
        )
        await _run_manager.on_text(
            api_url, color="green", end="\n", verbose=self.verbose
        )
        api_url = api_url.strip()
        api_response = await self.requests_wrapper.aget(api_url)
        await _run_manager.on_text(
            api_response, color="yellow", end="\n", verbose=self.verbose
        )
        answer = await self.api_answer_chain.apredict(
            question=question,
            api_docs=self.api_docs,
            api_url=api_url,
            api_response=api_response,
            callbacks=_run_manager.get_child(),
        )
        return {self.output_key: answer}
[docs]    @classmethod
    def from_llm_and_api_docs(
        cls,
        llm: BaseLanguageModel,
        api_docs: str,
        headers: Optional[dict] = None,
        api_url_prompt: BasePromptTemplate = API_URL_PROMPT,
        api_response_prompt: BasePromptTemplate = API_RESPONSE_PROMPT,
        **kwargs: Any,
    ) -> APIChain:
        """Load chain from just an LLM and the api docs."""
        get_request_chain = LLMChain(llm=llm, prompt=api_url_prompt)


requests_wrapper = TextRequestsWrapper(headers=headers)
        get_answer_chain = LLMChain(llm=llm, prompt=api_response_prompt)
        return cls(
            api_request_chain=get_request_chain,
            api_answer_chain=get_answer_chain,
            requests_wrapper=requests_wrapper,
            api_docs=api_docs,
            **kwargs,
        )
    @property
    def _chain_type(self) -> str:
        return "api_chain"
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.chains.api.openapi.chain
"""Chain that makes API calls and summarizes the responses to answer a question."""
from __future__ import annotations
import json
from typing import Any, Dict, List, NamedTuple, Optional, cast
from pydantic import BaseModel, Field
from requests import Response
from langchain.base_language import BaseLanguageModel
from langchain.callbacks.manager import CallbackManagerForChainRun, Callbacks
from langchain.chains.api.openapi.requests_chain import APIRequesterChain
from langchain.chains.api.openapi.response_chain import APIResponderChain
from langchain.chains.base import Chain
from langchain.chains.llm import LLMChain
from langchain.requests import Requests
from langchain.tools.openapi.utils.api_models import APIOperation
class _ParamMapping(NamedTuple):
    """Mapping from parameter name to parameter value."""
    query_params: List[str]
    body_params: List[str]
    path_params: List[str]
[docs]class OpenAPIEndpointChain(Chain, BaseModel):
    """Chain interacts with an OpenAPI endpoint using natural language."""
    api_request_chain: LLMChain
    api_response_chain: Optional[LLMChain]
    api_operation: APIOperation
    requests: Requests = Field(exclude=True, default_factory=Requests)
    param_mapping: _ParamMapping = Field(alias="param_mapping")
    return_intermediate_steps: bool = False
    instructions_key: str = "instructions"  #: :meta private:
    output_key: str = "output"  #: :meta private:
    max_text_length: Optional[int] = Field(ge=0)  #: :meta private:
    @property
    def input_keys(self) -> List[str]:
        """Expect input key.
        :meta private:
        """
        return [self.instructions_key]
    @property


"""
        return [self.instructions_key]
    @property
    def output_keys(self) -> List[str]:
        """Expect output key.
        :meta private:
        """
        if not self.return_intermediate_steps:
            return [self.output_key]
        else:
            return [self.output_key, "intermediate_steps"]
    def _construct_path(self, args: Dict[str, str]) -> str:
        """Construct the path from the deserialized input."""
        path = self.api_operation.base_url + self.api_operation.path
        for param in self.param_mapping.path_params:
            path = path.replace(f"{{{param}}}", str(args.pop(param, "")))
        return path
    def _extract_query_params(self, args: Dict[str, str]) -> Dict[str, str]:
        """Extract the query params from the deserialized input."""
        query_params = {}
        for param in self.param_mapping.query_params:
            if param in args:
                query_params[param] = args.pop(param)
        return query_params
    def _extract_body_params(self, args: Dict[str, str]) -> Optional[Dict[str, str]]:
        """Extract the request body params from the deserialized input."""
        body_params = None
        if self.param_mapping.body_params:
            body_params = {}
            for param in self.param_mapping.body_params:
                if param in args:
                    body_params[param] = args.pop(param)
        return body_params
[docs]    def deserialize_json_input(self, serialized_args: str) -> dict:
        """Use the serialized typescript dictionary.
        Resolve the path, query params dict, and optional requestBody dict.
        """
        args: dict = json.loads(serialized_args)
        path = self._construct_path(args)


path = self._construct_path(args)
        body_params = self._extract_body_params(args)
        query_params = self._extract_query_params(args)
        return {
            "url": path,
            "data": body_params,
            "params": query_params,
        }
    def _get_output(self, output: str, intermediate_steps: dict) -> dict:
        """Return the output from the API call."""
        if self.return_intermediate_steps:
            return {
                self.output_key: output,
                "intermediate_steps": intermediate_steps,
            }
        else:
            return {self.output_key: output}
    def _call(
        self,
        inputs: Dict[str, Any],
        run_manager: Optional[CallbackManagerForChainRun] = None,
    ) -> Dict[str, str]:
        _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager()
        intermediate_steps = {}
        instructions = inputs[self.instructions_key]
        instructions = instructions[: self.max_text_length]
        _api_arguments = self.api_request_chain.predict_and_parse(
            instructions=instructions, callbacks=_run_manager.get_child()
        )
        api_arguments = cast(str, _api_arguments)
        intermediate_steps["request_args"] = api_arguments
        _run_manager.on_text(
            api_arguments, color="green", end="\n", verbose=self.verbose
        )
        if api_arguments.startswith("ERROR"):
            return self._get_output(api_arguments, intermediate_steps)
        elif api_arguments.startswith("MESSAGE:"):
            return self._get_output(
                api_arguments[len("MESSAGE:") :], intermediate_steps
            )
        try:
            request_args = self.deserialize_json_input(api_arguments)
            method = getattr(self.requests, self.api_operation.method.value)


method = getattr(self.requests, self.api_operation.method.value)
            api_response: Response = method(**request_args)
            if api_response.status_code != 200:
                method_str = str(self.api_operation.method.value)
                response_text = (
                    f"{api_response.status_code}: {api_response.reason}"
                    + f"\nFor {method_str.upper()}  {request_args['url']}\n"
                    + f"Called with args: {request_args['params']}"
                )
            else:
                response_text = api_response.text
        except Exception as e:
            response_text = f"Error with message {str(e)}"
        response_text = response_text[: self.max_text_length]
        intermediate_steps["response_text"] = response_text
        _run_manager.on_text(
            response_text, color="blue", end="\n", verbose=self.verbose
        )
        if self.api_response_chain is not None:
            _answer = self.api_response_chain.predict_and_parse(
                response=response_text,
                instructions=instructions,
                callbacks=_run_manager.get_child(),
            )
            answer = cast(str, _answer)
            _run_manager.on_text(answer, color="yellow", end="\n", verbose=self.verbose)
            return self._get_output(answer, intermediate_steps)
        else:
            return self._get_output(response_text, intermediate_steps)
[docs]    @classmethod
    def from_url_and_method(
        cls,
        spec_url: str,
        path: str,
        method: str,
        llm: BaseLanguageModel,
        requests: Optional[Requests] = None,
        return_intermediate_steps: bool = False,
        **kwargs: Any
        # TODO: Handle async
    ) -> "OpenAPIEndpointChain":


# TODO: Handle async
    ) -> "OpenAPIEndpointChain":
        """Create an OpenAPIEndpoint from a spec at the specified url."""
        operation = APIOperation.from_openapi_url(spec_url, path, method)
        return cls.from_api_operation(
            operation,
            requests=requests,
            llm=llm,
            return_intermediate_steps=return_intermediate_steps,
            **kwargs,
        )
[docs]    @classmethod
    def from_api_operation(
        cls,
        operation: APIOperation,
        llm: BaseLanguageModel,
        requests: Optional[Requests] = None,
        verbose: bool = False,
        return_intermediate_steps: bool = False,
        raw_response: bool = False,
        callbacks: Callbacks = None,
        **kwargs: Any
        # TODO: Handle async
    ) -> "OpenAPIEndpointChain":
        """Create an OpenAPIEndpointChain from an operation and a spec."""
        param_mapping = _ParamMapping(
            query_params=operation.query_params,
            body_params=operation.body_params,
            path_params=operation.path_params,
        )
        requests_chain = APIRequesterChain.from_llm_and_typescript(
            llm,
            typescript_definition=operation.to_typescript(),
            verbose=verbose,
            callbacks=callbacks,
        )
        if raw_response:
            response_chain = None
        else:
            response_chain = APIResponderChain.from_llm(
                llm, verbose=verbose, callbacks=callbacks
            )
        _requests = requests or Requests()
        return cls(
            api_request_chain=requests_chain,
            api_response_chain=response_chain,
            api_operation=operation,
            requests=_requests,
            param_mapping=param_mapping,


requests=_requests,
            param_mapping=param_mapping,
            verbose=verbose,
            return_intermediate_steps=return_intermediate_steps,
            callbacks=callbacks,
            **kwargs,
        )
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.retrievers.chatgpt_plugin_retriever
from __future__ import annotations
from typing import List, Optional
import aiohttp
import requests
from pydantic import BaseModel
from langchain.schema import BaseRetriever, Document
[docs]class ChatGPTPluginRetriever(BaseRetriever, BaseModel):
    url: str
    bearer_token: str
    top_k: int = 3
    filter: Optional[dict] = None
    aiosession: Optional[aiohttp.ClientSession] = None
    class Config:
        """Configuration for this pydantic object."""
        arbitrary_types_allowed = True
[docs]    def get_relevant_documents(self, query: str) -> List[Document]:
        url, json, headers = self._create_request(query)
        response = requests.post(url, json=json, headers=headers)
        results = response.json()["results"][0]["results"]
        docs = []
        for d in results:
            content = d.pop("text")
            metadata = d.pop("metadata", d)
            if metadata.get("source_id"):
                metadata["source"] = metadata.pop("source_id")
            docs.append(Document(page_content=content, metadata=metadata))
        return docs
[docs]    async def aget_relevant_documents(self, query: str) -> List[Document]:
        url, json, headers = self._create_request(query)
        if not self.aiosession:
            async with aiohttp.ClientSession() as session:
                async with session.post(url, headers=headers, json=json) as response:
                    res = await response.json()
        else:
            async with self.aiosession.post(
                url, headers=headers, json=json
            ) as response:
                res = await response.json()


) as response:
                res = await response.json()
        results = res["results"][0]["results"]
        docs = []
        for d in results:
            content = d.pop("text")
            metadata = d.pop("metadata", d)
            if metadata.get("source_id"):
                metadata["source"] = metadata.pop("source_id")
            docs.append(Document(page_content=content, metadata=metadata))
        return docs
    def _create_request(self, query: str) -> tuple[str, dict, dict]:
        url = f"{self.url}/query"
        json = {
            "queries": [
                {
                    "query": query,
                    "filter": self.filter,
                    "top_k": self.top_k,
                }
            ]
        }
        headers = {
            "Content-Type": "application/json",
            "Authorization": f"Bearer {self.bearer_token}",
        }
        return url, json, headers
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.retrievers.elastic_search_bm25
"""Wrapper around Elasticsearch vector database."""
from __future__ import annotations
import uuid
from typing import Any, Iterable, List
from langchain.docstore.document import Document
from langchain.schema import BaseRetriever
[docs]class ElasticSearchBM25Retriever(BaseRetriever):
    """Wrapper around Elasticsearch using BM25 as a retrieval method.
    To connect to an Elasticsearch instance that requires login credentials,
    including Elastic Cloud, use the Elasticsearch URL format
    https://username:password@es_host:9243. For example, to connect to Elastic
    Cloud, create the Elasticsearch URL with the required authentication details and
    pass it to the ElasticVectorSearch constructor as the named parameter
    elasticsearch_url.
    You can obtain your Elastic Cloud URL and login credentials by logging in to the
    Elastic Cloud console at https://cloud.elastic.co, selecting your deployment, and
    navigating to the "Deployments" page.
    To obtain your Elastic Cloud password for the default "elastic" user:
    1. Log in to the Elastic Cloud console at https://cloud.elastic.co
    2. Go to "Security" > "Users"
    3. Locate the "elastic" user and click "Edit"
    4. Click "Reset password"
    5. Follow the prompts to reset the password
    The format for Elastic Cloud URLs is
    https://username:password@cluster_id.region_id.gcp.cloud.es.io:9243.
    """
    def __init__(self, client: Any, index_name: str):
        self.client = client
        self.index_name = index_name
[docs]    @classmethod
    def create(


self.index_name = index_name
[docs]    @classmethod
    def create(
        cls, elasticsearch_url: str, index_name: str, k1: float = 2.0, b: float = 0.75
    ) -> ElasticSearchBM25Retriever:
        from elasticsearch import Elasticsearch
        # Create an Elasticsearch client instance
        es = Elasticsearch(elasticsearch_url)
        # Define the index settings and mappings
        settings = {
            "analysis": {"analyzer": {"default": {"type": "standard"}}},
            "similarity": {
                "custom_bm25": {
                    "type": "BM25",
                    "k1": k1,
                    "b": b,
                }
            },
        }
        mappings = {
            "properties": {
                "content": {
                    "type": "text",
                    "similarity": "custom_bm25",  # Use the custom BM25 similarity
                }
            }
        }
        # Create the index with the specified settings and mappings
        es.indices.create(index=index_name, mappings=mappings, settings=settings)
        return cls(es, index_name)
[docs]    def add_texts(
        self,
        texts: Iterable[str],
        refresh_indices: bool = True,
    ) -> List[str]:
        """Run more texts through the embeddings and add to the retriver.
        Args:
            texts: Iterable of strings to add to the retriever.
            refresh_indices: bool to refresh ElasticSearch indices
        Returns:
            List of ids from adding the texts into the retriever.
        """
        try:
            from elasticsearch.helpers import bulk
        except ImportError:
            raise ValueError(
                "Could not import elasticsearch python package. "


raise ValueError(
                "Could not import elasticsearch python package. "
                "Please install it with `pip install elasticsearch`."
            )
        requests = []
        ids = []
        for i, text in enumerate(texts):
            _id = str(uuid.uuid4())
            request = {
                "_op_type": "index",
                "_index": self.index_name,
                "content": text,
                "_id": _id,
            }
            ids.append(_id)
            requests.append(request)
        bulk(self.client, requests)
        if refresh_indices:
            self.client.indices.refresh(index=self.index_name)
        return ids
[docs]    def get_relevant_documents(self, query: str) -> List[Document]:
        query_dict = {"query": {"match": {"content": query}}}
        res = self.client.search(index=self.index_name, body=query_dict)
        docs = []
        for r in res["hits"]["hits"]:
            docs.append(Document(page_content=r["_source"]["content"]))
        return docs
[docs]    async def aget_relevant_documents(self, query: str) -> List[Document]:
        raise NotImplementedError
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.retrievers.tfidf
"""TF-IDF Retriever.
Largely based on
https://github.com/asvskartheek/Text-Retrieval/blob/master/TF-IDF%20Search%20Engine%20(SKLEARN).ipynb"""
from __future__ import annotations
from typing import Any, Dict, Iterable, List, Optional
from pydantic import BaseModel
from langchain.schema import BaseRetriever, Document
[docs]class TFIDFRetriever(BaseRetriever, BaseModel):
    vectorizer: Any
    docs: List[Document]
    tfidf_array: Any
    k: int = 4
    class Config:
        """Configuration for this pydantic object."""
        arbitrary_types_allowed = True
[docs]    @classmethod
    def from_texts(
        cls,
        texts: Iterable[str],
        metadatas: Optional[Iterable[dict]] = None,
        tfidf_params: Optional[Dict[str, Any]] = None,
        **kwargs: Any,
    ) -> TFIDFRetriever:
        try:
            from sklearn.feature_extraction.text import TfidfVectorizer
        except ImportError:
            raise ImportError(
                "Could not import scikit-learn, please install with `pip install "
                "scikit-learn`."
            )
        tfidf_params = tfidf_params or {}
        vectorizer = TfidfVectorizer(**tfidf_params)
        tfidf_array = vectorizer.fit_transform(texts)
        metadatas = metadatas or ({} for _ in texts)
        docs = [Document(page_content=t, metadata=m) for t, m in zip(texts, metadatas)]


return cls(vectorizer=vectorizer, docs=docs, tfidf_array=tfidf_array, **kwargs)
[docs]    @classmethod
    def from_documents(
        cls,
        documents: Iterable[Document],
        *,
        tfidf_params: Optional[Dict[str, Any]] = None,
        **kwargs: Any,
    ) -> TFIDFRetriever:
        texts, metadatas = zip(*((d.page_content, d.metadata) for d in documents))
        return cls.from_texts(
            texts=texts, tfidf_params=tfidf_params, metadatas=metadatas, **kwargs
        )
[docs]    def get_relevant_documents(self, query: str) -> List[Document]:
        from sklearn.metrics.pairwise import cosine_similarity
        query_vec = self.vectorizer.transform(
            [query]
        )  # Ip -- (n_docs,x), Op -- (n_docs,n_Feats)
        results = cosine_similarity(self.tfidf_array, query_vec).reshape(
            (-1,)
        )  # Op -- (n_docs,1) -- Cosine Sim with each doc
        return_docs = [self.docs[i] for i in results.argsort()[-self.k :][::-1]]
        return return_docs
[docs]    async def aget_relevant_documents(self, query: str) -> List[Document]:
        raise NotImplementedError
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.retrievers.zep
from __future__ import annotations
from typing import TYPE_CHECKING, Dict, List, Optional
from langchain.schema import BaseRetriever, Document
if TYPE_CHECKING:
    from zep_python import MemorySearchResult
[docs]class ZepRetriever(BaseRetriever):
    """A Retriever implementation for the Zep long-term memory store. Search your
    user's long-term chat history with Zep.
    Note: You will need to provide the user's `session_id` to use this retriever.
    More on Zep:
    Zep provides long-term conversation storage for LLM apps. The server stores,
    summarizes, embeds, indexes, and enriches conversational AI chat
    histories, and exposes them via simple, low-latency APIs.
    For server installation instructions, see:
    https://getzep.github.io/deployment/quickstart/
    """
    def __init__(
        self,
        session_id: str,
        url: str,
        top_k: Optional[int] = None,
    ):
        try:
            from zep_python import ZepClient
        except ImportError:
            raise ValueError(
                "Could not import zep-python package. "
                "Please install it with `pip install zep-python`."
            )
        self.zep_client = ZepClient(base_url=url)
        self.session_id = session_id
        self.top_k = top_k
    def _search_result_to_doc(
        self, results: List[MemorySearchResult]
    ) -> List[Document]:
        return [
            Document(
                page_content=r.message.pop("content"),
                metadata={"score": r.dist, **r.message},
            )
            for r in results


)
            for r in results
            if r.message
        ]
[docs]    def get_relevant_documents(
        self, query: str, metadata: Optional[Dict] = None
    ) -> List[Document]:
        from zep_python import MemorySearchPayload
        payload: MemorySearchPayload = MemorySearchPayload(
            text=query, metadata=metadata
        )
        results: List[MemorySearchResult] = self.zep_client.search_memory(
            self.session_id, payload, limit=self.top_k
        )
        return self._search_result_to_doc(results)
[docs]    async def aget_relevant_documents(
        self, query: str, metadata: Optional[Dict] = None
    ) -> List[Document]:
        from zep_python import MemorySearchPayload
        payload: MemorySearchPayload = MemorySearchPayload(
            text=query, metadata=metadata
        )
        results: List[MemorySearchResult] = await self.zep_client.asearch_memory(
            self.session_id, payload, limit=self.top_k
        )
        return self._search_result_to_doc(results)
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.retrievers.remote_retriever
from typing import List, Optional
import aiohttp
import requests
from pydantic import BaseModel
from langchain.schema import BaseRetriever, Document
[docs]class RemoteLangChainRetriever(BaseRetriever, BaseModel):
    url: str
    headers: Optional[dict] = None
    input_key: str = "message"
    response_key: str = "response"
    page_content_key: str = "page_content"
    metadata_key: str = "metadata"
[docs]    def get_relevant_documents(self, query: str) -> List[Document]:
        response = requests.post(
            self.url, json={self.input_key: query}, headers=self.headers
        )
        result = response.json()
        return [
            Document(
                page_content=r[self.page_content_key], metadata=r[self.metadata_key]
            )
            for r in result[self.response_key]
        ]
[docs]    async def aget_relevant_documents(self, query: str) -> List[Document]:
        async with aiohttp.ClientSession() as session:
            async with session.request(
                "POST", self.url, headers=self.headers, json={self.input_key: query}
            ) as response:
                result = await response.json()
        return [
            Document(
                page_content=r[self.page_content_key], metadata=r[self.metadata_key]
            )
            for r in result[self.response_key]
        ]
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.retrievers.aws_kendra_index_retriever
"""Retriever wrapper for AWS Kendra."""
import re
from typing import Any, Dict, List
from langchain.schema import BaseRetriever, Document
[docs]class AwsKendraIndexRetriever(BaseRetriever):
    """Wrapper around AWS Kendra."""
    kendraindex: str
    """Kendra index id"""
    k: int
    """Number of documents to query for."""
    languagecode: str
    """Languagecode used for querying."""
    kclient: Any
    """ boto3 client for Kendra. """
    def __init__(
        self, kclient: Any, kendraindex: str, k: int = 3, languagecode: str = "en"
    ):
        self.kendraindex = kendraindex
        self.k = k
        self.languagecode = languagecode
        self.kclient = kclient
    def _clean_result(self, res_text: str) -> str:
        return re.sub("\s+", " ", res_text).replace("...", "")
    def _get_top_n_results(self, resp: Dict, count: int) -> Document:
        r = resp["ResultItems"][count]
        doc_title = r["DocumentTitle"]["Text"]
        doc_uri = r["DocumentURI"]
        r_type = r["Type"]
        if (
            r["AdditionalAttributes"]
            and r["AdditionalAttributes"][0]["Key"] == "AnswerText"
        ):
            res_text = r["AdditionalAttributes"][0]["Value"]["TextWithHighlightsValue"][
                "Text"
            ]
        else:
            res_text = r["DocumentExcerpt"]["Text"]
        doc_excerpt = self._clean_result(res_text)


doc_excerpt = self._clean_result(res_text)
        combined_text = f"""Document Title: {doc_title}
Document Excerpt: {doc_excerpt}
"""
        return Document(
            page_content=combined_text,
            metadata={
                "source": doc_uri,
                "title": doc_title,
                "excerpt": doc_excerpt,
                "type": r_type,
            },
        )
    def _kendra_query(self, kquery: str) -> List[Document]:
        response = self.kclient.query(
            IndexId=self.kendraindex,
            QueryText=kquery.strip(),
            AttributeFilter={
                "AndAllFilters": [
                    {
                        "EqualsTo": {
                            "Key": "_language_code",
                            "Value": {
                                "StringValue": self.languagecode,
                            },
                        }
                    }
                ]
            },
        )
        if len(response["ResultItems"]) > self.k:
            r_count = self.k
        else:
            r_count = len(response["ResultItems"])
        return [self._get_top_n_results(response, i) for i in range(0, r_count)]
[docs]    def get_relevant_documents(self, query: str) -> List[Document]:
        """Run search on Kendra index and get top k documents
        docs = get_relevant_documents('This is my query')
        """
        return self._kendra_query(query)
[docs]    async def aget_relevant_documents(self, query: str) -> List[Document]:
        raise NotImplementedError("AwsKendraIndexRetriever does not support async")
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.retrievers.svm
"""SMV Retriever.
Largely based on
https://github.com/karpathy/randomfun/blob/master/knn_vs_svm.ipynb"""
from __future__ import annotations
import concurrent.futures
from typing import Any, List, Optional
import numpy as np
from pydantic import BaseModel
from langchain.embeddings.base import Embeddings
from langchain.schema import BaseRetriever, Document
def create_index(contexts: List[str], embeddings: Embeddings) -> np.ndarray:
    with concurrent.futures.ThreadPoolExecutor() as executor:
        return np.array(list(executor.map(embeddings.embed_query, contexts)))
[docs]class SVMRetriever(BaseRetriever, BaseModel):
    embeddings: Embeddings
    index: Any
    texts: List[str]
    k: int = 4
    relevancy_threshold: Optional[float] = None
    class Config:
        """Configuration for this pydantic object."""
        arbitrary_types_allowed = True
[docs]    @classmethod
    def from_texts(
        cls, texts: List[str], embeddings: Embeddings, **kwargs: Any
    ) -> SVMRetriever:
        index = create_index(texts, embeddings)
        return cls(embeddings=embeddings, index=index, texts=texts, **kwargs)
[docs]    def get_relevant_documents(self, query: str) -> List[Document]:
        from sklearn import svm
        query_embeds = np.array(self.embeddings.embed_query(query))
        x = np.concatenate([query_embeds[None, ...], self.index])
        y = np.zeros(x.shape[0])
        y[0] = 1
        clf = svm.LinearSVC(


y[0] = 1
        clf = svm.LinearSVC(
            class_weight="balanced", verbose=False, max_iter=10000, tol=1e-6, C=0.1
        )
        clf.fit(x, y)
        similarities = clf.decision_function(x)
        sorted_ix = np.argsort(-similarities)
        # svm.LinearSVC in scikit-learn is non-deterministic.
        # if a text is the same as a query, there is no guarantee
        # the query will be in the first index.
        # this performs a simple swap, this works because anything
        # left of the 0 should be equivalent.
        zero_index = np.where(sorted_ix == 0)[0][0]
        if zero_index != 0:
            sorted_ix[0], sorted_ix[zero_index] = sorted_ix[zero_index], sorted_ix[0]
        denominator = np.max(similarities) - np.min(similarities) + 1e-6
        normalized_similarities = (similarities - np.min(similarities)) / denominator
        top_k_results = []
        for row in sorted_ix[1 : self.k + 1]:
            if (
                self.relevancy_threshold is None
                or normalized_similarities[row] >= self.relevancy_threshold
            ):
                top_k_results.append(Document(page_content=self.texts[row - 1]))
        return top_k_results
[docs]    async def aget_relevant_documents(self, query: str) -> List[Document]:
        raise NotImplementedError
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.retrievers.contextual_compression
"""Retriever that wraps a base retriever and filters the results."""
from typing import List
from pydantic import BaseModel, Extra
from langchain.retrievers.document_compressors.base import (
    BaseDocumentCompressor,
)
from langchain.schema import BaseRetriever, Document
[docs]class ContextualCompressionRetriever(BaseRetriever, BaseModel):
    """Retriever that wraps a base retriever and compresses the results."""
    base_compressor: BaseDocumentCompressor
    """Compressor for compressing retrieved documents."""
    base_retriever: BaseRetriever
    """Base Retriever to use for getting relevant documents."""
    class Config:
        """Configuration for this pydantic object."""
        extra = Extra.forbid
        arbitrary_types_allowed = True
[docs]    def get_relevant_documents(self, query: str) -> List[Document]:
        """Get documents relevant for a query.
        Args:
            query: string to find relevant documents for
        Returns:
            Sequence of relevant documents
        """
        docs = self.base_retriever.get_relevant_documents(query)
        compressed_docs = self.base_compressor.compress_documents(docs, query)
        return list(compressed_docs)
[docs]    async def aget_relevant_documents(self, query: str) -> List[Document]:
        """Get documents relevant for a query.
        Args:
            query: string to find relevant documents for
        Returns:
            List of relevant documents
        """
        docs = await self.base_retriever.aget_relevant_documents(query)
        compressed_docs = await self.base_compressor.acompress_documents(docs, query)
        return list(compressed_docs)
By Harrison Chase


return list(compressed_docs)
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.retrievers.time_weighted_retriever
"""Retriever that combines embedding similarity with recency in retrieving values."""
import datetime
from copy import deepcopy
from typing import Any, Dict, List, Optional, Tuple
from pydantic import BaseModel, Field
from langchain.schema import BaseRetriever, Document
from langchain.vectorstores.base import VectorStore
def _get_hours_passed(time: datetime.datetime, ref_time: datetime.datetime) -> float:
    """Get the hours passed between two datetime objects."""
    return (time - ref_time).total_seconds() / 3600
[docs]class TimeWeightedVectorStoreRetriever(BaseRetriever, BaseModel):
    """Retriever combining embedding similarity with recency."""
    vectorstore: VectorStore
    """The vectorstore to store documents and determine salience."""
    search_kwargs: dict = Field(default_factory=lambda: dict(k=100))
    """Keyword arguments to pass to the vectorstore similarity search."""
    # TODO: abstract as a queue
    memory_stream: List[Document] = Field(default_factory=list)
    """The memory_stream of documents to search through."""
    decay_rate: float = Field(default=0.01)
    """The exponential decay factor used as (1.0-decay_rate)**(hrs_passed)."""
    k: int = 4
    """The maximum number of documents to retrieve in a given call."""
    other_score_keys: List[str] = []
    """Other keys in the metadata to factor into the score, e.g. 'importance'."""
    default_salience: Optional[float] = None
    """The salience to assign memories not retrieved from the vector store.
    None assigns no salience to documents not fetched from the vector store.
    """
    class Config:


"""
    class Config:
        """Configuration for this pydantic object."""
        arbitrary_types_allowed = True
    def _get_combined_score(
        self,
        document: Document,
        vector_relevance: Optional[float],
        current_time: datetime.datetime,
    ) -> float:
        """Return the combined score for a document."""
        hours_passed = _get_hours_passed(
            current_time,
            document.metadata["last_accessed_at"],
        )
        score = (1.0 - self.decay_rate) ** hours_passed
        for key in self.other_score_keys:
            if key in document.metadata:
                score += document.metadata[key]
        if vector_relevance is not None:
            score += vector_relevance
        return score
[docs]    def get_salient_docs(self, query: str) -> Dict[int, Tuple[Document, float]]:
        """Return documents that are salient to the query."""
        docs_and_scores: List[Tuple[Document, float]]
        docs_and_scores = self.vectorstore.similarity_search_with_relevance_scores(
            query, **self.search_kwargs
        )
        results = {}
        for fetched_doc, relevance in docs_and_scores:
            if "buffer_idx" in fetched_doc.metadata:
                buffer_idx = fetched_doc.metadata["buffer_idx"]
                doc = self.memory_stream[buffer_idx]
                results[buffer_idx] = (doc, relevance)
        return results
[docs]    def get_relevant_documents(self, query: str) -> List[Document]:
        """Return documents that are relevant to the query."""
        current_time = datetime.datetime.now()
        docs_and_scores = {
            doc.metadata["buffer_idx"]: (doc, self.default_salience)
            for doc in self.memory_stream[-self.k :]


for doc in self.memory_stream[-self.k :]
        }
        # If a doc is considered salient, update the salience score
        docs_and_scores.update(self.get_salient_docs(query))
        rescored_docs = [
            (doc, self._get_combined_score(doc, relevance, current_time))
            for doc, relevance in docs_and_scores.values()
        ]
        rescored_docs.sort(key=lambda x: x[1], reverse=True)
        result = []
        # Ensure frequently accessed memories aren't forgotten
        for doc, _ in rescored_docs[: self.k]:
            # TODO: Update vector store doc once `update` method is exposed.
            buffered_doc = self.memory_stream[doc.metadata["buffer_idx"]]
            buffered_doc.metadata["last_accessed_at"] = current_time
            result.append(buffered_doc)
        return result
[docs]    async def aget_relevant_documents(self, query: str) -> List[Document]:
        """Return documents that are relevant to the query."""
        raise NotImplementedError
[docs]    def add_documents(self, documents: List[Document], **kwargs: Any) -> List[str]:
        """Add documents to vectorstore."""
        current_time = kwargs.get("current_time")
        if current_time is None:
            current_time = datetime.datetime.now()
        # Avoid mutating input documents
        dup_docs = [deepcopy(d) for d in documents]
        for i, doc in enumerate(dup_docs):
            if "last_accessed_at" not in doc.metadata:
                doc.metadata["last_accessed_at"] = current_time
            if "created_at" not in doc.metadata:
                doc.metadata["created_at"] = current_time
            doc.metadata["buffer_idx"] = len(self.memory_stream) + i


doc.metadata["buffer_idx"] = len(self.memory_stream) + i
        self.memory_stream.extend(dup_docs)
        return self.vectorstore.add_documents(dup_docs, **kwargs)
[docs]    async def aadd_documents(
        self, documents: List[Document], **kwargs: Any
    ) -> List[str]:
        """Add documents to vectorstore."""
        current_time = kwargs.get("current_time")
        if current_time is None:
            current_time = datetime.datetime.now()
        # Avoid mutating input documents
        dup_docs = [deepcopy(d) for d in documents]
        for i, doc in enumerate(dup_docs):
            if "last_accessed_at" not in doc.metadata:
                doc.metadata["last_accessed_at"] = current_time
            if "created_at" not in doc.metadata:
                doc.metadata["created_at"] = current_time
            doc.metadata["buffer_idx"] = len(self.memory_stream) + i
        self.memory_stream.extend(dup_docs)
        return await self.vectorstore.aadd_documents(dup_docs, **kwargs)
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.retrievers.knn
"""KNN Retriever.
Largely based on
https://github.com/karpathy/randomfun/blob/master/knn_vs_svm.ipynb"""
from __future__ import annotations
import concurrent.futures
from typing import Any, List, Optional
import numpy as np
from pydantic import BaseModel
from langchain.embeddings.base import Embeddings
from langchain.schema import BaseRetriever, Document
def create_index(contexts: List[str], embeddings: Embeddings) -> np.ndarray:
    with concurrent.futures.ThreadPoolExecutor() as executor:
        return np.array(list(executor.map(embeddings.embed_query, contexts)))
[docs]class KNNRetriever(BaseRetriever, BaseModel):
    embeddings: Embeddings
    index: Any
    texts: List[str]
    k: int = 4
    relevancy_threshold: Optional[float] = None
    class Config:
        """Configuration for this pydantic object."""
        arbitrary_types_allowed = True
[docs]    @classmethod
    def from_texts(
        cls, texts: List[str], embeddings: Embeddings, **kwargs: Any
    ) -> KNNRetriever:
        index = create_index(texts, embeddings)
        return cls(embeddings=embeddings, index=index, texts=texts, **kwargs)
[docs]    def get_relevant_documents(self, query: str) -> List[Document]:
        query_embeds = np.array(self.embeddings.embed_query(query))
        # calc L2 norm
        index_embeds = self.index / np.sqrt((self.index**2).sum(1, keepdims=True))
        query_embeds = query_embeds / np.sqrt((query_embeds**2).sum())
        similarities = index_embeds.dot(query_embeds)


similarities = index_embeds.dot(query_embeds)
        sorted_ix = np.argsort(-similarities)
        denominator = np.max(similarities) - np.min(similarities) + 1e-6
        normalized_similarities = (similarities - np.min(similarities)) / denominator
        top_k_results = [
            Document(page_content=self.texts[row])
            for row in sorted_ix[0 : self.k]
            if (
                self.relevancy_threshold is None
                or normalized_similarities[row] >= self.relevancy_threshold
            )
        ]
        return top_k_results
[docs]    async def aget_relevant_documents(self, query: str) -> List[Document]:
        raise NotImplementedError
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.retrievers.azure_cognitive_search
"""Retriever wrapper for Azure Cognitive Search."""
from __future__ import annotations
import json
from typing import Dict, List, Optional
import aiohttp
import requests
from pydantic import BaseModel, Extra, root_validator
from langchain.schema import BaseRetriever, Document
from langchain.utils import get_from_dict_or_env
[docs]class AzureCognitiveSearchRetriever(BaseRetriever, BaseModel):
    """Wrapper around Azure Cognitive Search."""
    service_name: str = ""
    """Name of Azure Cognitive Search service"""
    index_name: str = ""
    """Name of Index inside Azure Cognitive Search service"""
    api_key: str = ""
    """API Key. Both Admin and Query keys work, but for reading data it's
    recommended to use a Query key."""
    api_version: str = "2020-06-30"
    """API version"""
    aiosession: Optional[aiohttp.ClientSession] = None
    """ClientSession, in case we want to reuse connection for better performance."""
    content_key: str = "content"
    """Key in a retrieved result to set as the Document page_content."""
    class Config:
        extra = Extra.forbid
        arbitrary_types_allowed = True
    @root_validator(pre=True)
    def validate_environment(cls, values: Dict) -> Dict:
        """Validate that service name, index name and api key exists in environment."""
        values["service_name"] = get_from_dict_or_env(
            values, "service_name", "AZURE_COGNITIVE_SEARCH_SERVICE_NAME"
        )
        values["index_name"] = get_from_dict_or_env(
            values, "index_name", "AZURE_COGNITIVE_SEARCH_INDEX_NAME"
        )


)
        values["api_key"] = get_from_dict_or_env(
            values, "api_key", "AZURE_COGNITIVE_SEARCH_API_KEY"
        )
        return values
    def _build_search_url(self, query: str) -> str:
        base_url = f"https://{self.service_name}.search.windows.net/"
        endpoint_path = f"indexes/{self.index_name}/docs?api-version={self.api_version}"
        return base_url + endpoint_path + f"&search={query}"
    @property
    def _headers(self) -> Dict[str, str]:
        return {
            "Content-Type": "application/json",
            "api-key": self.api_key,
        }
    def _search(self, query: str) -> List[dict]:
        search_url = self._build_search_url(query)
        response = requests.get(search_url, headers=self._headers)
        if response.status_code != 200:
            raise Exception(f"Error in search request: {response}")
        return json.loads(response.text)["value"]
    async def _asearch(self, query: str) -> List[dict]:
        search_url = self._build_search_url(query)
        if not self.aiosession:
            async with aiohttp.ClientSession() as session:
                async with session.get(search_url, headers=self._headers) as response:
                    response_json = await response.json()
        else:
            async with self.aiosession.get(
                search_url, headers=self._headers
            ) as response:
                response_json = await response.json()
        return response_json["value"]
[docs]    def get_relevant_documents(self, query: str) -> List[Document]:
        search_results = self._search(query)
        return [


search_results = self._search(query)
        return [
            Document(page_content=result.pop(self.content_key), metadata=result)
            for result in search_results
        ]
[docs]    async def aget_relevant_documents(self, query: str) -> List[Document]:
        search_results = await self._asearch(query)
        return [
            Document(page_content=result.pop(self.content_key), metadata=result)
            for result in search_results
        ]
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.retrievers.weaviate_hybrid_search
"""Wrapper around weaviate vector database."""
from __future__ import annotations
from typing import Any, Dict, List, Optional
from uuid import uuid4
from pydantic import Extra
from langchain.docstore.document import Document
from langchain.schema import BaseRetriever
[docs]class WeaviateHybridSearchRetriever(BaseRetriever):
    def __init__(
        self,
        client: Any,
        index_name: str,
        text_key: str,
        alpha: float = 0.5,
        k: int = 4,
        attributes: Optional[List[str]] = None,
        create_schema_if_missing: bool = True,
    ):
        try:
            import weaviate
        except ImportError:
            raise ImportError(
                "Could not import weaviate python package. "
                "Please install it with `pip install weaviate-client`."
            )
        if not isinstance(client, weaviate.Client):
            raise ValueError(
                f"client should be an instance of weaviate.Client, got {type(client)}"
            )
        self._client = client
        self.k = k
        self.alpha = alpha
        self._index_name = index_name
        self._text_key = text_key
        self._query_attrs = [self._text_key]
        if attributes is not None:
            self._query_attrs.extend(attributes)
        if create_schema_if_missing:
            self._create_schema_if_missing()
    def _create_schema_if_missing(self) -> None:
        class_obj = {
            "class": self._index_name,
            "properties": [{"name": self._text_key, "dataType": ["text"]}],


"properties": [{"name": self._text_key, "dataType": ["text"]}],
            "vectorizer": "text2vec-openai",
        }
        if not self._client.schema.exists(self._index_name):
            self._client.schema.create_class(class_obj)
[docs]    class Config:
        """Configuration for this pydantic object."""
        extra = Extra.forbid
        arbitrary_types_allowed = True
    # added text_key
[docs]    def add_documents(self, docs: List[Document], **kwargs: Any) -> List[str]:
        """Upload documents to Weaviate."""
        from weaviate.util import get_valid_uuid
        with self._client.batch as batch:
            ids = []
            for i, doc in enumerate(docs):
                metadata = doc.metadata or {}
                data_properties = {self._text_key: doc.page_content, **metadata}
                # If the UUID of one of the objects already exists
                # then the existing objectwill be replaced by the new object.
                if "uuids" in kwargs:
                    _id = kwargs["uuids"][i]
                else:
                    _id = get_valid_uuid(uuid4())
                batch.add_data_object(data_properties, self._index_name, _id)
                ids.append(_id)
        return ids
[docs]    def get_relevant_documents(
        self, query: str, where_filter: Optional[Dict[str, object]] = None
    ) -> List[Document]:
        """Look up similar documents in Weaviate."""
        query_obj = self._client.query.get(self._index_name, self._query_attrs)
        if where_filter:
            query_obj = query_obj.with_where(where_filter)


if where_filter:
            query_obj = query_obj.with_where(where_filter)
        result = query_obj.with_hybrid(query, alpha=self.alpha).with_limit(self.k).do()
        if "errors" in result:
            raise ValueError(f"Error during query: {result['errors']}")
        docs = []
        for res in result["data"]["Get"][self._index_name]:
            text = res.pop(self._text_key)
            docs.append(Document(page_content=text, metadata=res))
        return docs
[docs]    async def aget_relevant_documents(
        self, query: str, where_filter: Optional[Dict[str, object]] = None
    ) -> List[Document]:
        raise NotImplementedError
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.retrievers.pinecone_hybrid_search
"""Taken from: https://docs.pinecone.io/docs/hybrid-search"""
import hashlib
from typing import Any, Dict, List, Optional
from pydantic import BaseModel, Extra, root_validator
from langchain.embeddings.base import Embeddings
from langchain.schema import BaseRetriever, Document
def hash_text(text: str) -> str:
    return str(hashlib.sha256(text.encode("utf-8")).hexdigest())
def create_index(
    contexts: List[str],
    index: Any,
    embeddings: Embeddings,
    sparse_encoder: Any,
    ids: Optional[List[str]] = None,
    metadatas: Optional[List[dict]] = None,
) -> None:
    batch_size = 32
    _iterator = range(0, len(contexts), batch_size)
    try:
        from tqdm.auto import tqdm
        _iterator = tqdm(_iterator)
    except ImportError:
        pass
    if ids is None:
        # create unique ids using hash of the text
        ids = [hash_text(context) for context in contexts]
    for i in _iterator:
        # find end of batch
        i_end = min(i + batch_size, len(contexts))
        # extract batch
        context_batch = contexts[i:i_end]
        batch_ids = ids[i:i_end]
        metadata_batch = (
            metadatas[i:i_end] if metadatas else [{} for _ in context_batch]
        )
        # add context passages as metadata
        meta = [
            {"context": context, **metadata}
            for context, metadata in zip(context_batch, metadata_batch)
        ]
        # create dense vectors
        dense_embeds = embeddings.embed_documents(context_batch)


# create dense vectors
        dense_embeds = embeddings.embed_documents(context_batch)
        # create sparse vectors
        sparse_embeds = sparse_encoder.encode_documents(context_batch)
        for s in sparse_embeds:
            s["values"] = [float(s1) for s1 in s["values"]]
        vectors = []
        # loop through the data and create dictionaries for upserts
        for doc_id, sparse, dense, metadata in zip(
            batch_ids, sparse_embeds, dense_embeds, meta
        ):
            vectors.append(
                {
                    "id": doc_id,
                    "sparse_values": sparse,
                    "values": dense,
                    "metadata": metadata,
                }
            )
        # upload the documents to the new hybrid index
        index.upsert(vectors)
[docs]class PineconeHybridSearchRetriever(BaseRetriever, BaseModel):
    embeddings: Embeddings
    sparse_encoder: Any
    index: Any
    top_k: int = 4
    alpha: float = 0.5
    class Config:
        """Configuration for this pydantic object."""
        extra = Extra.forbid
        arbitrary_types_allowed = True
[docs]    def add_texts(
        self,
        texts: List[str],
        ids: Optional[List[str]] = None,
        metadatas: Optional[List[dict]] = None,
    ) -> None:
        create_index(
            texts,
            self.index,
            self.embeddings,
            self.sparse_encoder,
            ids=ids,
            metadatas=metadatas,
        )
    @root_validator()
    def validate_environment(cls, values: Dict) -> Dict:
        """Validate that api key and python package exists in environment."""
        try:


"""Validate that api key and python package exists in environment."""
        try:
            from pinecone_text.hybrid import hybrid_convex_scale  # noqa:F401
            from pinecone_text.sparse.base_sparse_encoder import (
                BaseSparseEncoder,  # noqa:F401
            )
        except ImportError:
            raise ValueError(
                "Could not import pinecone_text python package. "
                "Please install it with `pip install pinecone_text`."
            )
        return values
[docs]    def get_relevant_documents(self, query: str) -> List[Document]:
        from pinecone_text.hybrid import hybrid_convex_scale
        sparse_vec = self.sparse_encoder.encode_queries(query)
        # convert the question into a dense vector
        dense_vec = self.embeddings.embed_query(query)
        # scale alpha with hybrid_scale
        dense_vec, sparse_vec = hybrid_convex_scale(dense_vec, sparse_vec, self.alpha)
        sparse_vec["values"] = [float(s1) for s1 in sparse_vec["values"]]
        # query pinecone with the query parameters
        result = self.index.query(
            vector=dense_vec,
            sparse_vector=sparse_vec,
            top_k=self.top_k,
            include_metadata=True,
        )
        final_result = []
        for res in result["matches"]:
            context = res["metadata"].pop("context")
            final_result.append(
                Document(page_content=context, metadata=res["metadata"])
            )
        # return search results as json
        return final_result
[docs]    async def aget_relevant_documents(self, query: str) -> List[Document]:
        raise NotImplementedError
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.retrievers.vespa_retriever
"""Wrapper for retrieving documents from Vespa."""
from __future__ import annotations
import json
from typing import TYPE_CHECKING, Any, Dict, List, Literal, Optional, Sequence, Union
from langchain.schema import BaseRetriever, Document
if TYPE_CHECKING:
    from vespa.application import Vespa
[docs]class VespaRetriever(BaseRetriever):
    def __init__(
        self,
        app: Vespa,
        body: Dict,
        content_field: str,
        metadata_fields: Optional[Sequence[str]] = None,
    ):
        self._application = app
        self._query_body = body
        self._content_field = content_field
        self._metadata_fields = metadata_fields or ()
    def _query(self, body: Dict) -> List[Document]:
        response = self._application.query(body)
        if not str(response.status_code).startswith("2"):
            raise RuntimeError(
                "Could not retrieve data from Vespa. Error code: {}".format(
                    response.status_code
                )
            )
        root = response.json["root"]
        if "errors" in root:
            raise RuntimeError(json.dumps(root["errors"]))
        docs = []
        for child in response.hits:
            page_content = child["fields"].pop(self._content_field, "")
            if self._metadata_fields == "*":
                metadata = child["fields"]
            else:
                metadata = {mf: child["fields"].get(mf) for mf in self._metadata_fields}
            metadata["id"] = child["id"]
            docs.append(Document(page_content=page_content, metadata=metadata))
        return docs


docs.append(Document(page_content=page_content, metadata=metadata))
        return docs
[docs]    def get_relevant_documents(self, query: str) -> List[Document]:
        body = self._query_body.copy()
        body["query"] = query
        return self._query(body)
[docs]    async def aget_relevant_documents(self, query: str) -> List[Document]:
        raise NotImplementedError
[docs]    def get_relevant_documents_with_filter(
        self, query: str, *, _filter: Optional[str] = None
    ) -> List[Document]:
        body = self._query_body.copy()
        _filter = f" and {_filter}" if _filter else ""
        body["yql"] = body["yql"] + _filter
        body["query"] = query
        return self._query(body)
[docs]    @classmethod
    def from_params(
        cls,
        url: str,
        content_field: str,
        *,
        k: Optional[int] = None,
        metadata_fields: Union[Sequence[str], Literal["*"]] = (),
        sources: Union[Sequence[str], Literal["*"], None] = None,
        _filter: Optional[str] = None,
        yql: Optional[str] = None,
        **kwargs: Any,
    ) -> VespaRetriever:
        """Instantiate retriever from params.
        Args:
            url (str): Vespa app URL.
            content_field (str): Field in results to return as Document page_content.
            k (Optional[int]): Number of Documents to return. Defaults to None.
            metadata_fields(Sequence[str] or "*"): Fields in results to include in
                document metadata. Defaults to empty tuple ().


document metadata. Defaults to empty tuple ().
            sources (Sequence[str] or "*" or None): Sources to retrieve
                from. Defaults to None.
            _filter (Optional[str]): Document filter condition expressed in YQL.
                Defaults to None.
            yql (Optional[str]): Full YQL query to be used. Should not be specified
                if _filter or sources are specified. Defaults to None.
            kwargs (Any): Keyword arguments added to query body.
        """
        try:
            from vespa.application import Vespa
        except ImportError:
            raise ImportError(
                "pyvespa is not installed, please install with `pip install pyvespa`"
            )
        app = Vespa(url)
        body = kwargs.copy()
        if yql and (sources or _filter):
            raise ValueError(
                "yql should only be specified if both sources and _filter are not "
                "specified."
            )
        else:
            if metadata_fields == "*":
                _fields = "*"
                body["summary"] = "short"
            else:
                _fields = ", ".join([content_field] + list(metadata_fields or []))
            _sources = ", ".join(sources) if isinstance(sources, Sequence) else "*"
            _filter = f" and {_filter}" if _filter else ""
            yql = f"select {_fields} from sources {_sources} where userQuery(){_filter}"
        body["yql"] = yql
        if k:
            body["hits"] = k
        return cls(app, body, content_field, metadata_fields=metadata_fields)
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.retrievers.pupmed
from typing import List
from langchain.schema import BaseRetriever, Document
from langchain.utilities.pupmed import PubMedAPIWrapper
[docs]class PubMedRetriever(BaseRetriever, PubMedAPIWrapper):
    """
    It is effectively a wrapper for PubMedAPIWrapper.
    It wraps load() to get_relevant_documents().
    It uses all PubMedAPIWrapper arguments without any change.
    """
[docs]    def get_relevant_documents(self, query: str) -> List[Document]:
        return self.load_docs(query=query)
[docs]    async def aget_relevant_documents(self, query: str) -> List[Document]:
        raise NotImplementedError
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.retrievers.arxiv
from typing import List
from langchain.schema import BaseRetriever, Document
from langchain.utilities.arxiv import ArxivAPIWrapper
[docs]class ArxivRetriever(BaseRetriever, ArxivAPIWrapper):
    """
    It is effectively a wrapper for ArxivAPIWrapper.
    It wraps load() to get_relevant_documents().
    It uses all ArxivAPIWrapper arguments without any change.
    """
[docs]    def get_relevant_documents(self, query: str) -> List[Document]:
        return self.load(query=query)
[docs]    async def aget_relevant_documents(self, query: str) -> List[Document]:
        raise NotImplementedError
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.retrievers.databerry
from typing import List, Optional
import aiohttp
import requests
from langchain.schema import BaseRetriever, Document
[docs]class DataberryRetriever(BaseRetriever):
    datastore_url: str
    top_k: Optional[int]
    api_key: Optional[str]
    def __init__(
        self,
        datastore_url: str,
        top_k: Optional[int] = None,
        api_key: Optional[str] = None,
    ):
        self.datastore_url = datastore_url
        self.api_key = api_key
        self.top_k = top_k
[docs]    def get_relevant_documents(self, query: str) -> List[Document]:
        response = requests.post(
            self.datastore_url,
            json={
                "query": query,
                **({"topK": self.top_k} if self.top_k is not None else {}),
            },
            headers={
                "Content-Type": "application/json",
                **(
                    {"Authorization": f"Bearer {self.api_key}"}
                    if self.api_key is not None
                    else {}
                ),
            },
        )
        data = response.json()
        return [
            Document(
                page_content=r["text"],
                metadata={"source": r["source"], "score": r["score"]},
            )
            for r in data["results"]
        ]
[docs]    async def aget_relevant_documents(self, query: str) -> List[Document]:
        async with aiohttp.ClientSession() as session:
            async with session.request(
                "POST",
                self.datastore_url,
                json={
                    "query": query,


self.datastore_url,
                json={
                    "query": query,
                    **({"topK": self.top_k} if self.top_k is not None else {}),
                },
                headers={
                    "Content-Type": "application/json",
                    **(
                        {"Authorization": f"Bearer {self.api_key}"}
                        if self.api_key is not None
                        else {}
                    ),
                },
            ) as response:
                data = await response.json()
        return [
            Document(
                page_content=r["text"],
                metadata={"source": r["source"], "score": r["score"]},
            )
            for r in data["results"]
        ]
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.retrievers.wikipedia
from typing import List
from langchain.schema import BaseRetriever, Document
from langchain.utilities.wikipedia import WikipediaAPIWrapper
[docs]class WikipediaRetriever(BaseRetriever, WikipediaAPIWrapper):
    """
    It is effectively a wrapper for WikipediaAPIWrapper.
    It wraps load() to get_relevant_documents().
    It uses all WikipediaAPIWrapper arguments without any change.
    """
[docs]    def get_relevant_documents(self, query: str) -> List[Document]:
        return self.load(query=query)
[docs]    async def aget_relevant_documents(self, query: str) -> List[Document]:
        raise NotImplementedError
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on Jun 16, 2023.


Source code for langchain.retrievers.merger_retriever
from typing import List
from langchain.schema import BaseRetriever, Document
[docs]class MergerRetriever(BaseRetriever):
    """
    This class merges the results of multiple retrievers.
    Args:
        retrievers: A list of retrievers to merge.
    """
    def __init__(
        self,
        retrievers: List[BaseRetriever],
    ):
        """
        Initialize the MergerRetriever class.
        Args:
            retrievers: A list of retrievers to merge.
        """
        self.retrievers = retrievers
[docs]    def get_relevant_documents(self, query: str) -> List[Document]:
        """
        Get the relevant documents for a given query.
        Args:
            query: The query to search for.
        Returns:
            A list of relevant documents.
        """
        # Merge the results of the retrievers.
        merged_documents = self.merge_documents(query)
        return merged_documents
[docs]    async def aget_relevant_documents(self, query: str) -> List[Document]:
        """
        Asynchronously get the relevant documents for a given query.
        Args:
            query: The query to search for.
        Returns:
            A list of relevant documents.
        """
        # Merge the results of the retrievers.
        merged_documents = await self.amerge_documents(query)
        return merged_documents
[docs]    def merge_documents(self, query: str) -> List[Document]:
        """
        Merge the results of the retrievers.
        Args:
            query: The query to search for.
        Returns:
            A list of merged documents.
        """