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) -> Dict[str, Any]: _run_manager = run_manager or AsyncCallbackManagerForChainRun.get_noop_manager() callbacks = _run_manager.get_child() _input = inputs[self.input_key] color_mapping = get_color_mapping([str(i) for i in range(len(self.chains))]) for i, chain in enumerate(self.chains): _input = await chain.arun(_input, callbacks=callbacks) if self.strip_outputs: _input = _input.strip() await _run_manager.on_text( _input, color=color_mapping[str(i)], end="\n", verbose=self.verbose ) return {self.output_key: _input}
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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]
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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"
https://api.python.langchain.com/en/stable/_modules/langchain/chains/qa_with_sources/vector_db.html
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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)
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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)
https://api.python.langchain.com/en/stable/_modules/langchain/chains/qa_with_sources/retrieval.html
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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,
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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.
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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
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} 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]:
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return inputs.pop(self.input_docs_key) @property def _chain_type(self) -> str: return "qa_with_sources_chain"
https://api.python.langchain.com/en/stable/_modules/langchain/chains/qa_with_sources/base.html
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Source code for langchain.chains.flare.base from __future__ import annotations import re from abc import abstractmethod from typing import Any, Dict, List, Optional, Sequence, Tuple import numpy as np from pydantic import Field from langchain.base_language import BaseLanguageModel from langchain.callbacks.manager import ( CallbackManagerForChainRun, ) from langchain.chains.base import Chain from langchain.chains.flare.prompts import ( PROMPT, QUESTION_GENERATOR_PROMPT, FinishedOutputParser, ) from langchain.chains.llm import LLMChain from langchain.llms import OpenAI from langchain.prompts import BasePromptTemplate from langchain.schema import BaseRetriever, Generation class _ResponseChain(LLMChain): prompt: BasePromptTemplate = PROMPT @property def input_keys(self) -> List[str]: return self.prompt.input_variables def generate_tokens_and_log_probs( self, _input: Dict[str, Any], *, run_manager: Optional[CallbackManagerForChainRun] = None, ) -> Tuple[Sequence[str], Sequence[float]]: llm_result = self.generate([_input], run_manager=run_manager) return self._extract_tokens_and_log_probs(llm_result.generations[0]) @abstractmethod def _extract_tokens_and_log_probs( self, generations: List[Generation] ) -> Tuple[Sequence[str], Sequence[float]]: """Extract tokens and log probs from response.""" class _OpenAIResponseChain(_ResponseChain): llm: OpenAI = Field( default_factory=lambda: OpenAI( max_tokens=32, model_kwargs={"logprobs": 1}, temperature=0 )
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) ) def _extract_tokens_and_log_probs( self, generations: List[Generation] ) -> Tuple[Sequence[str], Sequence[float]]: tokens = [] log_probs = [] for gen in generations: if gen.generation_info is None: raise ValueError tokens.extend(gen.generation_info["logprobs"]["tokens"]) log_probs.extend(gen.generation_info["logprobs"]["token_logprobs"]) return tokens, log_probs class QuestionGeneratorChain(LLMChain): prompt: BasePromptTemplate = QUESTION_GENERATOR_PROMPT @property def input_keys(self) -> List[str]: return ["user_input", "context", "response"] def _low_confidence_spans( tokens: Sequence[str], log_probs: Sequence[float], min_prob: float, min_token_gap: int, num_pad_tokens: int, ) -> List[str]: _low_idx = np.where(np.exp(log_probs) < min_prob)[0] low_idx = [i for i in _low_idx if re.search(r"\w", tokens[i])] if len(low_idx) == 0: return [] spans = [[low_idx[0], low_idx[0] + num_pad_tokens + 1]] for i, idx in enumerate(low_idx[1:]): end = idx + num_pad_tokens + 1 if idx - low_idx[i] < min_token_gap: spans[-1][1] = end else: spans.append([idx, end]) return ["".join(tokens[start:end]) for start, end in spans] [docs]class FlareChain(Chain): question_generator_chain: QuestionGeneratorChain
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[docs]class FlareChain(Chain): question_generator_chain: QuestionGeneratorChain response_chain: _ResponseChain = Field(default_factory=_OpenAIResponseChain) output_parser: FinishedOutputParser = Field(default_factory=FinishedOutputParser) retriever: BaseRetriever min_prob: float = 0.2 min_token_gap: int = 5 num_pad_tokens: int = 2 max_iter: int = 10 start_with_retrieval: bool = True @property def input_keys(self) -> List[str]: return ["user_input"] @property def output_keys(self) -> List[str]: return ["response"] def _do_generation( self, questions: List[str], user_input: str, response: str, _run_manager: CallbackManagerForChainRun, ) -> Tuple[str, bool]: callbacks = _run_manager.get_child() docs = [] for question in questions: docs.extend(self.retriever.get_relevant_documents(question)) context = "\n\n".join(d.page_content for d in docs) result = self.response_chain.predict( user_input=user_input, context=context, response=response, callbacks=callbacks, ) marginal, finished = self.output_parser.parse(result) return marginal, finished def _do_retrieval( self, low_confidence_spans: List[str], _run_manager: CallbackManagerForChainRun, user_input: str, response: str, initial_response: str, ) -> Tuple[str, bool]: question_gen_inputs = [ { "user_input": user_input,
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question_gen_inputs = [ { "user_input": user_input, "current_response": initial_response, "uncertain_span": span, } for span in low_confidence_spans ] callbacks = _run_manager.get_child() question_gen_outputs = self.question_generator_chain.apply( question_gen_inputs, callbacks=callbacks ) questions = [ output[self.question_generator_chain.output_keys[0]] for output in question_gen_outputs ] _run_manager.on_text( f"Generated Questions: {questions}", color="yellow", end="\n" ) return self._do_generation(questions, user_input, response, _run_manager) def _call( self, inputs: Dict[str, Any], run_manager: Optional[CallbackManagerForChainRun] = None, ) -> Dict[str, Any]: _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager() user_input = inputs[self.input_keys[0]] response = "" for i in range(self.max_iter): _run_manager.on_text( f"Current Response: {response}", color="blue", end="\n" ) _input = {"user_input": user_input, "context": "", "response": response} tokens, log_probs = self.response_chain.generate_tokens_and_log_probs( _input, run_manager=_run_manager ) low_confidence_spans = _low_confidence_spans( tokens, log_probs, self.min_prob, self.min_token_gap, self.num_pad_tokens, ) initial_response = response.strip() + " " + "".join(tokens)
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) initial_response = response.strip() + " " + "".join(tokens) if not low_confidence_spans: response = initial_response final_response, finished = self.output_parser.parse(response) if finished: return {self.output_keys[0]: final_response} continue marginal, finished = self._do_retrieval( low_confidence_spans, _run_manager, user_input, response, initial_response, ) response = response.strip() + " " + marginal if finished: break return {self.output_keys[0]: response} [docs] @classmethod def from_llm( cls, llm: BaseLanguageModel, max_generation_len: int = 32, **kwargs: Any ) -> FlareChain: question_gen_chain = QuestionGeneratorChain(llm=llm) response_llm = OpenAI( max_tokens=max_generation_len, model_kwargs={"logprobs": 1}, temperature=0 ) response_chain = _OpenAIResponseChain(llm=response_llm) return cls( question_generator_chain=question_gen_chain, response_chain=response_chain, **kwargs, )
https://api.python.langchain.com/en/stable/_modules/langchain/chains/flare/base.html
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Source code for langchain.chains.natbot.base """Implement an LLM driven browser.""" from __future__ import annotations import warnings from typing import Any, Dict, List, Optional from pydantic import Extra, root_validator from langchain.base_language import BaseLanguageModel from langchain.callbacks.manager import CallbackManagerForChainRun from langchain.chains.base import Chain from langchain.chains.llm import LLMChain from langchain.chains.natbot.prompt import PROMPT from langchain.llms.openai import OpenAI [docs]class NatBotChain(Chain): """Implement an LLM driven browser. Example: .. code-block:: python from langchain import NatBotChain natbot = NatBotChain.from_default("Buy me a new hat.") """ llm_chain: LLMChain objective: str """Objective that NatBot is tasked with completing.""" llm: Optional[BaseLanguageModel] = None """[Deprecated] LLM wrapper to use.""" input_url_key: str = "url" #: :meta private: input_browser_content_key: str = "browser_content" #: :meta private: previous_command: str = "" #: :meta private: output_key: str = "command" #: :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( "Directly instantiating an NatBotChain with an llm is deprecated. " "Please instantiate with llm_chain argument or using the from_llm "
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"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: values["llm_chain"] = LLMChain(llm=values["llm"], prompt=PROMPT) return values [docs] @classmethod def from_default(cls, objective: str, **kwargs: Any) -> NatBotChain: """Load with default LLMChain.""" llm = OpenAI(temperature=0.5, best_of=10, n=3, max_tokens=50) return cls.from_llm(llm, objective, **kwargs) [docs] @classmethod def from_llm( cls, llm: BaseLanguageModel, objective: str, **kwargs: Any ) -> NatBotChain: """Load from LLM.""" llm_chain = LLMChain(llm=llm, prompt=PROMPT) return cls(llm_chain=llm_chain, objective=objective, **kwargs) @property def input_keys(self) -> List[str]: """Expect url and browser content. :meta private: """ return [self.input_url_key, self.input_browser_content_key] @property def output_keys(self) -> List[str]: """Return command. :meta private: """ return [self.output_key] def _call( self, inputs: Dict[str, str], run_manager: Optional[CallbackManagerForChainRun] = None, ) -> Dict[str, str]: _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager()
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_run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager() url = inputs[self.input_url_key] browser_content = inputs[self.input_browser_content_key] llm_cmd = self.llm_chain.predict( objective=self.objective, url=url[:100], previous_command=self.previous_command, browser_content=browser_content[:4500], callbacks=_run_manager.get_child(), ) llm_cmd = llm_cmd.strip() self.previous_command = llm_cmd return {self.output_key: llm_cmd} [docs] def execute(self, url: str, browser_content: str) -> str: """Figure out next browser command to run. Args: url: URL of the site currently on. browser_content: Content of the page as currently displayed by the browser. Returns: Next browser command to run. Example: .. code-block:: python browser_content = "...." llm_command = natbot.run("www.google.com", browser_content) """ _inputs = { self.input_url_key: url, self.input_browser_content_key: browser_content, } return self(_inputs)[self.output_key] @property def _chain_type(self) -> str: return "nat_bot_chain"
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Source code for langchain.chains.hyde.base """Hypothetical Document Embeddings. https://arxiv.org/abs/2212.10496 """ from __future__ import annotations from typing import Any, Dict, List, Optional import numpy as np from pydantic import Extra from langchain.base_language import BaseLanguageModel from langchain.callbacks.manager import CallbackManagerForChainRun from langchain.chains.base import Chain from langchain.chains.hyde.prompts import PROMPT_MAP from langchain.chains.llm import LLMChain from langchain.embeddings.base import Embeddings [docs]class HypotheticalDocumentEmbedder(Chain, Embeddings): """Generate hypothetical document for query, and then embed that. Based on https://arxiv.org/abs/2212.10496 """ base_embeddings: Embeddings llm_chain: LLMChain class Config: """Configuration for this pydantic object.""" extra = Extra.forbid arbitrary_types_allowed = True @property def input_keys(self) -> List[str]: """Input keys for Hyde's LLM chain.""" return self.llm_chain.input_keys @property def output_keys(self) -> List[str]: """Output keys for Hyde's LLM chain.""" return self.llm_chain.output_keys [docs] def embed_documents(self, texts: List[str]) -> List[List[float]]: """Call the base embeddings.""" return self.base_embeddings.embed_documents(texts) [docs] def combine_embeddings(self, embeddings: List[List[float]]) -> List[float]: """Combine embeddings into final embeddings.""" return list(np.array(embeddings).mean(axis=0))
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return list(np.array(embeddings).mean(axis=0)) [docs] def embed_query(self, text: str) -> List[float]: """Generate a hypothetical document and embedded it.""" var_name = self.llm_chain.input_keys[0] result = self.llm_chain.generate([{var_name: text}]) documents = [generation.text for generation in result.generations[0]] embeddings = self.embed_documents(documents) return self.combine_embeddings(embeddings) def _call( self, inputs: Dict[str, Any], run_manager: Optional[CallbackManagerForChainRun] = None, ) -> Dict[str, str]: """Call the internal llm chain.""" _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager() return self.llm_chain(inputs, callbacks=_run_manager.get_child()) [docs] @classmethod def from_llm( cls, llm: BaseLanguageModel, base_embeddings: Embeddings, prompt_key: str, **kwargs: Any, ) -> HypotheticalDocumentEmbedder: """Load and use LLMChain for a specific prompt key.""" prompt = PROMPT_MAP[prompt_key] llm_chain = LLMChain(llm=llm, prompt=prompt) return cls(base_embeddings=base_embeddings, llm_chain=llm_chain, **kwargs) @property def _chain_type(self) -> str: return "hyde_chain"
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Source code for langchain.chains.sql_database.base """Chain for interacting with SQL Database.""" from __future__ import annotations import warnings 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 CallbackManagerForChainRun from langchain.chains.base import Chain from langchain.chains.llm import LLMChain from langchain.chains.sql_database.prompt import DECIDER_PROMPT, PROMPT, SQL_PROMPTS from langchain.prompts.base import BasePromptTemplate from langchain.prompts.prompt import PromptTemplate from langchain.sql_database import SQLDatabase from langchain.tools.sql_database.prompt import QUERY_CHECKER INTERMEDIATE_STEPS_KEY = "intermediate_steps" [docs]class SQLDatabaseChain(Chain): """Chain for interacting with SQL Database. Example: .. code-block:: python from langchain import SQLDatabaseChain, OpenAI, SQLDatabase db = SQLDatabase(...) db_chain = SQLDatabaseChain.from_llm(OpenAI(), db) """ llm_chain: LLMChain llm: Optional[BaseLanguageModel] = None """[Deprecated] LLM wrapper to use.""" database: SQLDatabase = Field(exclude=True) """SQL Database to connect to.""" prompt: Optional[BasePromptTemplate] = None """[Deprecated] Prompt to use to translate natural language to SQL.""" top_k: int = 5 """Number of results to return from the query""" input_key: str = "query" #: :meta private: output_key: str = "result" #: :meta private: return_intermediate_steps: bool = False
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return_intermediate_steps: bool = False """Whether or not to return the intermediate steps along with the final answer.""" return_direct: bool = False """Whether or not to return the result of querying the SQL table directly.""" use_query_checker: bool = False """Whether or not the query checker tool should be used to attempt to fix the initial SQL from the LLM.""" query_checker_prompt: Optional[BasePromptTemplate] = None """The prompt template that should be used by the query checker""" 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( "Directly instantiating an SQLDatabaseChain 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: database = values["database"] prompt = values.get("prompt") or SQL_PROMPTS.get( database.dialect, PROMPT ) values["llm_chain"] = LLMChain(llm=values["llm"], prompt=prompt) return values @property def input_keys(self) -> List[str]: """Return the singular input key. :meta private: """ return [self.input_key] @property def output_keys(self) -> List[str]: """Return the singular output key. :meta private: """ if not self.return_intermediate_steps:
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:meta private: """ if not self.return_intermediate_steps: return [self.output_key] else: return [self.output_key, INTERMEDIATE_STEPS_KEY] def _call( self, inputs: Dict[str, Any], run_manager: Optional[CallbackManagerForChainRun] = None, ) -> Dict[str, Any]: _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager() input_text = f"{inputs[self.input_key]}\nSQLQuery:" _run_manager.on_text(input_text, verbose=self.verbose) # If not present, then defaults to None which is all tables. table_names_to_use = inputs.get("table_names_to_use") table_info = self.database.get_table_info(table_names=table_names_to_use) llm_inputs = { "input": input_text, "top_k": str(self.top_k), "dialect": self.database.dialect, "table_info": table_info, "stop": ["\nSQLResult:"], } intermediate_steps: List = [] try: intermediate_steps.append(llm_inputs) # input: sql generation sql_cmd = self.llm_chain.predict( callbacks=_run_manager.get_child(), **llm_inputs, ).strip() if not self.use_query_checker: _run_manager.on_text(sql_cmd, color="green", verbose=self.verbose) intermediate_steps.append( sql_cmd ) # output: sql generation (no checker) intermediate_steps.append({"sql_cmd": sql_cmd}) # input: sql exec result = self.database.run(sql_cmd)
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result = self.database.run(sql_cmd) intermediate_steps.append(str(result)) # output: sql exec else: query_checker_prompt = self.query_checker_prompt or PromptTemplate( template=QUERY_CHECKER, input_variables=["query", "dialect"] ) query_checker_chain = LLMChain( llm=self.llm_chain.llm, prompt=query_checker_prompt ) query_checker_inputs = { "query": sql_cmd, "dialect": self.database.dialect, } checked_sql_command: str = query_checker_chain.predict( callbacks=_run_manager.get_child(), **query_checker_inputs ).strip() intermediate_steps.append( checked_sql_command ) # output: sql generation (checker) _run_manager.on_text( checked_sql_command, color="green", verbose=self.verbose ) intermediate_steps.append( {"sql_cmd": checked_sql_command} ) # input: sql exec result = self.database.run(checked_sql_command) intermediate_steps.append(str(result)) # output: sql exec sql_cmd = checked_sql_command _run_manager.on_text("\nSQLResult: ", verbose=self.verbose) _run_manager.on_text(result, color="yellow", verbose=self.verbose) # If return direct, we just set the final result equal to # the result of the sql query result, otherwise try to get a human readable # final answer if self.return_direct: final_result = result else: _run_manager.on_text("\nAnswer:", verbose=self.verbose) input_text += f"{sql_cmd}\nSQLResult: {result}\nAnswer:" llm_inputs["input"] = input_text
https://api.python.langchain.com/en/stable/_modules/langchain/chains/sql_database/base.html
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llm_inputs["input"] = input_text intermediate_steps.append(llm_inputs) # input: final answer final_result = self.llm_chain.predict( callbacks=_run_manager.get_child(), **llm_inputs, ).strip() intermediate_steps.append(final_result) # output: final answer _run_manager.on_text(final_result, color="green", verbose=self.verbose) chain_result: Dict[str, Any] = {self.output_key: final_result} if self.return_intermediate_steps: chain_result[INTERMEDIATE_STEPS_KEY] = intermediate_steps return chain_result except Exception as exc: # Append intermediate steps to exception, to aid in logging and later # improvement of few shot prompt seeds exc.intermediate_steps = intermediate_steps # type: ignore raise exc @property def _chain_type(self) -> str: return "sql_database_chain" [docs] @classmethod def from_llm( cls, llm: BaseLanguageModel, db: SQLDatabase, prompt: Optional[BasePromptTemplate] = None, **kwargs: Any, ) -> SQLDatabaseChain: prompt = prompt or SQL_PROMPTS.get(db.dialect, PROMPT) llm_chain = LLMChain(llm=llm, prompt=prompt) return cls(llm_chain=llm_chain, database=db, **kwargs) [docs]class SQLDatabaseSequentialChain(Chain): """Chain for querying SQL database that is a sequential chain. The chain is as follows: 1. Based on the query, determine which tables to use. 2. Based on those tables, call the normal SQL database chain.
https://api.python.langchain.com/en/stable/_modules/langchain/chains/sql_database/base.html
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2. Based on those tables, call the normal SQL database chain. This is useful in cases where the number of tables in the database is large. """ decider_chain: LLMChain sql_chain: SQLDatabaseChain input_key: str = "query" #: :meta private: output_key: str = "result" #: :meta private: return_intermediate_steps: bool = False [docs] @classmethod def from_llm( cls, llm: BaseLanguageModel, database: SQLDatabase, query_prompt: BasePromptTemplate = PROMPT, decider_prompt: BasePromptTemplate = DECIDER_PROMPT, **kwargs: Any, ) -> SQLDatabaseSequentialChain: """Load the necessary chains.""" sql_chain = SQLDatabaseChain.from_llm( llm, database, prompt=query_prompt, **kwargs ) decider_chain = LLMChain( llm=llm, prompt=decider_prompt, output_key="table_names" ) return cls(sql_chain=sql_chain, decider_chain=decider_chain, **kwargs) @property def input_keys(self) -> List[str]: """Return the singular input key. :meta private: """ return [self.input_key] @property def output_keys(self) -> List[str]: """Return the singular output key. :meta private: """ if not self.return_intermediate_steps: return [self.output_key] else: return [self.output_key, INTERMEDIATE_STEPS_KEY] def _call( self, inputs: Dict[str, Any],
https://api.python.langchain.com/en/stable/_modules/langchain/chains/sql_database/base.html
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def _call( self, inputs: Dict[str, Any], run_manager: Optional[CallbackManagerForChainRun] = None, ) -> Dict[str, Any]: _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager() _table_names = self.sql_chain.database.get_usable_table_names() table_names = ", ".join(_table_names) llm_inputs = { "query": inputs[self.input_key], "table_names": table_names, } _lowercased_table_names = [name.lower() for name in _table_names] table_names_from_chain = self.decider_chain.predict_and_parse(**llm_inputs) table_names_to_use = [ name for name in table_names_from_chain if name.lower() in _lowercased_table_names ] _run_manager.on_text("Table names to use:", end="\n", verbose=self.verbose) _run_manager.on_text( str(table_names_to_use), color="yellow", verbose=self.verbose ) new_inputs = { self.sql_chain.input_key: inputs[self.input_key], "table_names_to_use": table_names_to_use, } return self.sql_chain( new_inputs, callbacks=_run_manager.get_child(), return_only_outputs=True ) @property def _chain_type(self) -> str: return "sql_database_sequential_chain"
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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(
https://api.python.langchain.com/en/stable/_modules/langchain/chains/llm_math/base.html
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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]:
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) -> 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
https://api.python.langchain.com/en/stable/_modules/langchain/chains/llm_math/base.html
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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,
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[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)
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Source code for langchain.chains.llm_bash.base """Chain that interprets a prompt and executes bash code to perform bash operations.""" from __future__ import annotations import logging import warnings 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 CallbackManagerForChainRun from langchain.chains.base import Chain from langchain.chains.llm import LLMChain from langchain.chains.llm_bash.prompt import PROMPT from langchain.prompts.base import BasePromptTemplate from langchain.schema import OutputParserException from langchain.utilities.bash import BashProcess logger = logging.getLogger(__name__) [docs]class LLMBashChain(Chain): """Chain that interprets a prompt and executes bash code to perform bash operations. Example: .. code-block:: python from langchain import LLMBashChain, OpenAI llm_bash = LLMBashChain.from_llm(OpenAI()) """ llm_chain: LLMChain llm: Optional[BaseLanguageModel] = None """[Deprecated] LLM wrapper to use.""" input_key: str = "question" #: :meta private: output_key: str = "answer" #: :meta private: prompt: BasePromptTemplate = PROMPT """[Deprecated]""" bash_process: BashProcess = Field(default_factory=BashProcess) #: :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:
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def raise_deprecation(cls, values: Dict) -> Dict: if "llm" in values: warnings.warn( "Directly instantiating an LLMBashChain with an llm is deprecated. " "Please instantiate with llm_chain 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 @root_validator def validate_prompt(cls, values: Dict) -> Dict: if values["llm_chain"].prompt.output_parser is None: raise ValueError( "The prompt used by llm_chain is expected to have an output_parser." ) 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 _call( self, inputs: Dict[str, Any], 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], verbose=self.verbose) t = self.llm_chain.predict( question=inputs[self.input_key], callbacks=_run_manager.get_child() ) _run_manager.on_text(t, color="green", verbose=self.verbose)
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) _run_manager.on_text(t, color="green", verbose=self.verbose) t = t.strip() try: parser = self.llm_chain.prompt.output_parser command_list = parser.parse(t) # type: ignore[union-attr] except OutputParserException as e: _run_manager.on_chain_error(e, verbose=self.verbose) raise e if self.verbose: _run_manager.on_text("\nCode: ", verbose=self.verbose) _run_manager.on_text( str(command_list), color="yellow", verbose=self.verbose ) output = self.bash_process.run(command_list) _run_manager.on_text("\nAnswer: ", verbose=self.verbose) _run_manager.on_text(output, color="yellow", verbose=self.verbose) return {self.output_key: output} @property def _chain_type(self) -> str: return "llm_bash_chain" [docs] @classmethod def from_llm( cls, llm: BaseLanguageModel, prompt: BasePromptTemplate = PROMPT, **kwargs: Any, ) -> LLMBashChain: llm_chain = LLMChain(llm=llm, prompt=prompt) return cls(llm_chain=llm_chain, **kwargs)
https://api.python.langchain.com/en/stable/_modules/langchain/chains/llm_bash/base.html
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Source code for langchain.chains.qa_generation.base from __future__ import annotations import json from typing import Any, Dict, List, Optional from pydantic import Field from langchain.base_language import BaseLanguageModel from langchain.callbacks.manager import CallbackManagerForChainRun from langchain.chains.base import Chain from langchain.chains.llm import LLMChain from langchain.chains.qa_generation.prompt import PROMPT_SELECTOR from langchain.prompts.base import BasePromptTemplate from langchain.text_splitter import RecursiveCharacterTextSplitter, TextSplitter [docs]class QAGenerationChain(Chain): llm_chain: LLMChain text_splitter: TextSplitter = Field( default=RecursiveCharacterTextSplitter(chunk_overlap=500) ) input_key: str = "text" output_key: str = "questions" k: Optional[int] = None [docs] @classmethod def from_llm( cls, llm: BaseLanguageModel, prompt: Optional[BasePromptTemplate] = None, **kwargs: Any, ) -> QAGenerationChain: _prompt = prompt or PROMPT_SELECTOR.get_prompt(llm) chain = LLMChain(llm=llm, prompt=_prompt) return cls(llm_chain=chain, **kwargs) @property def _chain_type(self) -> str: raise NotImplementedError @property def input_keys(self) -> List[str]: return [self.input_key] @property def output_keys(self) -> List[str]: return [self.output_key] def _call( self, inputs: Dict[str, Any],
https://api.python.langchain.com/en/stable/_modules/langchain/chains/qa_generation/base.html
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def _call( self, inputs: Dict[str, Any], run_manager: Optional[CallbackManagerForChainRun] = None, ) -> Dict[str, List]: docs = self.text_splitter.create_documents([inputs[self.input_key]]) results = self.llm_chain.generate( [{"text": d.page_content} for d in docs], run_manager=run_manager ) qa = [json.loads(res[0].text) for res in results.generations] return {self.output_key: qa}
https://api.python.langchain.com/en/stable/_modules/langchain/chains/qa_generation/base.html
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Source code for langchain.chains.router.multi_prompt """Use a single chain to route an input to one of multiple llm chains.""" from __future__ import annotations from typing import Any, Dict, List, Mapping, Optional from langchain.base_language import BaseLanguageModel from langchain.chains import ConversationChain from langchain.chains.llm import LLMChain from langchain.chains.router.base import MultiRouteChain, RouterChain from langchain.chains.router.llm_router import LLMRouterChain, RouterOutputParser from langchain.chains.router.multi_prompt_prompt import MULTI_PROMPT_ROUTER_TEMPLATE from langchain.prompts import PromptTemplate [docs]class MultiPromptChain(MultiRouteChain): """A multi-route chain that uses an LLM router chain to choose amongst prompts.""" router_chain: RouterChain """Chain for deciding a destination chain and the input to it.""" destination_chains: Mapping[str, LLMChain] """Map of name to candidate chains that inputs can be routed to.""" default_chain: LLMChain """Default chain to use when router doesn't map input to one of the destinations.""" @property def output_keys(self) -> List[str]: return ["text"] [docs] @classmethod def from_prompts( cls, llm: BaseLanguageModel, prompt_infos: List[Dict[str, str]], default_chain: Optional[LLMChain] = None, **kwargs: Any, ) -> MultiPromptChain: """Convenience constructor for instantiating from destination prompts.""" destinations = [f"{p['name']}: {p['description']}" for p in prompt_infos] destinations_str = "\n".join(destinations) router_template = MULTI_PROMPT_ROUTER_TEMPLATE.format(
https://api.python.langchain.com/en/stable/_modules/langchain/chains/router/multi_prompt.html
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router_template = MULTI_PROMPT_ROUTER_TEMPLATE.format( destinations=destinations_str ) router_prompt = PromptTemplate( template=router_template, input_variables=["input"], output_parser=RouterOutputParser(), ) router_chain = LLMRouterChain.from_llm(llm, router_prompt) destination_chains = {} for p_info in prompt_infos: name = p_info["name"] prompt_template = p_info["prompt_template"] prompt = PromptTemplate(template=prompt_template, input_variables=["input"]) chain = LLMChain(llm=llm, prompt=prompt) destination_chains[name] = chain _default_chain = default_chain or ConversationChain(llm=llm, output_key="text") return cls( router_chain=router_chain, destination_chains=destination_chains, default_chain=_default_chain, **kwargs, )
https://api.python.langchain.com/en/stable/_modules/langchain/chains/router/multi_prompt.html
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Source code for langchain.chains.router.multi_retrieval_qa """Use a single chain to route an input to one of multiple retrieval qa chains.""" from __future__ import annotations from typing import Any, Dict, List, Mapping, Optional from langchain.base_language import BaseLanguageModel from langchain.chains import ConversationChain from langchain.chains.base import Chain from langchain.chains.conversation.prompt import DEFAULT_TEMPLATE from langchain.chains.retrieval_qa.base import BaseRetrievalQA, RetrievalQA from langchain.chains.router.base import MultiRouteChain from langchain.chains.router.llm_router import LLMRouterChain, RouterOutputParser from langchain.chains.router.multi_retrieval_prompt import ( MULTI_RETRIEVAL_ROUTER_TEMPLATE, ) from langchain.chat_models import ChatOpenAI from langchain.prompts import PromptTemplate from langchain.schema import BaseRetriever [docs]class MultiRetrievalQAChain(MultiRouteChain): """A multi-route chain that uses an LLM router chain to choose amongst retrieval qa chains.""" router_chain: LLMRouterChain """Chain for deciding a destination chain and the input to it.""" destination_chains: Mapping[str, BaseRetrievalQA] """Map of name to candidate chains that inputs can be routed to.""" default_chain: Chain """Default chain to use when router doesn't map input to one of the destinations.""" @property def output_keys(self) -> List[str]: return ["result"] [docs] @classmethod def from_retrievers( cls, llm: BaseLanguageModel, retriever_infos: List[Dict[str, Any]], default_retriever: Optional[BaseRetriever] = None,
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default_retriever: Optional[BaseRetriever] = None, default_prompt: Optional[PromptTemplate] = None, default_chain: Optional[Chain] = None, **kwargs: Any, ) -> MultiRetrievalQAChain: if default_prompt and not default_retriever: raise ValueError( "`default_retriever` must be specified if `default_prompt` is " "provided. Received only `default_prompt`." ) destinations = [f"{r['name']}: {r['description']}" for r in retriever_infos] destinations_str = "\n".join(destinations) router_template = MULTI_RETRIEVAL_ROUTER_TEMPLATE.format( destinations=destinations_str ) router_prompt = PromptTemplate( template=router_template, input_variables=["input"], output_parser=RouterOutputParser(next_inputs_inner_key="query"), ) router_chain = LLMRouterChain.from_llm(llm, router_prompt) destination_chains = {} for r_info in retriever_infos: prompt = r_info.get("prompt") retriever = r_info["retriever"] chain = RetrievalQA.from_llm(llm, prompt=prompt, retriever=retriever) name = r_info["name"] destination_chains[name] = chain if default_chain: _default_chain = default_chain elif default_retriever: _default_chain = RetrievalQA.from_llm( llm, prompt=default_prompt, retriever=default_retriever ) else: prompt_template = DEFAULT_TEMPLATE.replace("input", "query") prompt = PromptTemplate(
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prompt = PromptTemplate( template=prompt_template, input_variables=["history", "query"] ) _default_chain = ConversationChain( llm=ChatOpenAI(), prompt=prompt, input_key="query", output_key="result" ) return cls( router_chain=router_chain, destination_chains=destination_chains, default_chain=_default_chain, **kwargs, )
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Source code for langchain.chains.router.base """Base classes for chain routing.""" from __future__ import annotations from abc import ABC from typing import Any, Dict, List, Mapping, NamedTuple, Optional from pydantic import Extra from langchain.callbacks.manager import ( AsyncCallbackManagerForChainRun, CallbackManagerForChainRun, Callbacks, ) from langchain.chains.base import Chain class Route(NamedTuple): destination: Optional[str] next_inputs: Dict[str, Any] [docs]class RouterChain(Chain, ABC): """Chain that outputs the name of a destination chain and the inputs to it.""" @property def output_keys(self) -> List[str]: return ["destination", "next_inputs"] [docs] def route(self, inputs: Dict[str, Any], callbacks: Callbacks = None) -> Route: result = self(inputs, callbacks=callbacks) return Route(result["destination"], result["next_inputs"]) [docs] async def aroute( self, inputs: Dict[str, Any], callbacks: Callbacks = None ) -> Route: result = await self.acall(inputs, callbacks=callbacks) return Route(result["destination"], result["next_inputs"]) [docs]class MultiRouteChain(Chain): """Use a single chain to route an input to one of multiple candidate chains.""" router_chain: RouterChain """Chain that routes inputs to destination chains.""" destination_chains: Mapping[str, Chain] """Chains that return final answer to inputs.""" default_chain: Chain """Default chain to use when none of the destination chains are suitable.""" silent_errors: bool = False """If True, use default_chain when an invalid destination name is provided.
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"""If True, use default_chain when an invalid destination name is provided. Defaults to False.""" class Config: """Configuration for this pydantic object.""" extra = Extra.forbid arbitrary_types_allowed = True @property def input_keys(self) -> List[str]: """Will be whatever keys the router chain prompt expects. :meta private: """ return self.router_chain.input_keys @property def output_keys(self) -> List[str]: """Will always return text key. :meta private: """ return [] def _call( self, inputs: Dict[str, Any], run_manager: Optional[CallbackManagerForChainRun] = None, ) -> Dict[str, Any]: _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager() callbacks = _run_manager.get_child() route = self.router_chain.route(inputs, callbacks=callbacks) _run_manager.on_text( str(route.destination) + ": " + str(route.next_inputs), verbose=self.verbose ) if not route.destination: return self.default_chain(route.next_inputs, callbacks=callbacks) elif route.destination in self.destination_chains: return self.destination_chains[route.destination]( route.next_inputs, callbacks=callbacks ) elif self.silent_errors: return self.default_chain(route.next_inputs, callbacks=callbacks) else: raise ValueError( f"Received invalid destination chain name '{route.destination}'" ) async def _acall( self, inputs: Dict[str, Any], run_manager: Optional[AsyncCallbackManagerForChainRun] = None,
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run_manager: Optional[AsyncCallbackManagerForChainRun] = None, ) -> Dict[str, Any]: _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager() callbacks = _run_manager.get_child() route = await self.router_chain.aroute(inputs, callbacks=callbacks) _run_manager.on_text( str(route.destination) + ": " + str(route.next_inputs), verbose=self.verbose ) if not route.destination: return await self.default_chain.acall( route.next_inputs, callbacks=callbacks ) elif route.destination in self.destination_chains: return await self.destination_chains[route.destination].acall( route.next_inputs, callbacks=callbacks ) elif self.silent_errors: return await self.default_chain.acall( route.next_inputs, callbacks=callbacks ) else: raise ValueError( f"Received invalid destination chain name '{route.destination}'" )
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Source code for langchain.chains.router.llm_router """Base classes for LLM-powered router chains.""" from __future__ import annotations from typing import Any, Dict, List, Optional, Type, cast from pydantic import root_validator from langchain.base_language import BaseLanguageModel from langchain.callbacks.manager import ( AsyncCallbackManagerForChainRun, CallbackManagerForChainRun, ) from langchain.chains import LLMChain from langchain.chains.router.base import RouterChain from langchain.output_parsers.json import parse_and_check_json_markdown from langchain.prompts import BasePromptTemplate from langchain.schema import BaseOutputParser, OutputParserException [docs]class LLMRouterChain(RouterChain): """A router chain that uses an LLM chain to perform routing.""" llm_chain: LLMChain """LLM chain used to perform routing""" @root_validator() def validate_prompt(cls, values: dict) -> dict: prompt = values["llm_chain"].prompt if prompt.output_parser is None: raise ValueError( "LLMRouterChain requires base llm_chain prompt to have an output" " parser that converts LLM text output to a dictionary with keys" " 'destination' and 'next_inputs'. Received a prompt with no output" " parser." ) return values @property def input_keys(self) -> List[str]: """Will be whatever keys the LLM chain prompt expects. :meta private: """ return self.llm_chain.input_keys def _validate_outputs(self, outputs: Dict[str, Any]) -> None: super()._validate_outputs(outputs) if not isinstance(outputs["next_inputs"], dict): raise ValueError def _call(
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raise ValueError def _call( self, inputs: Dict[str, Any], run_manager: Optional[CallbackManagerForChainRun] = None, ) -> Dict[str, Any]: _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager() callbacks = _run_manager.get_child() output = cast( Dict[str, Any], self.llm_chain.predict_and_parse(callbacks=callbacks, **inputs), ) return output async def _acall( self, inputs: Dict[str, Any], run_manager: Optional[AsyncCallbackManagerForChainRun] = None, ) -> Dict[str, Any]: _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager() callbacks = _run_manager.get_child() output = cast( Dict[str, Any], await self.llm_chain.apredict_and_parse(callbacks=callbacks, **inputs), ) return output [docs] @classmethod def from_llm( cls, llm: BaseLanguageModel, prompt: BasePromptTemplate, **kwargs: Any ) -> LLMRouterChain: """Convenience constructor.""" llm_chain = LLMChain(llm=llm, prompt=prompt) return cls(llm_chain=llm_chain, **kwargs) class RouterOutputParser(BaseOutputParser[Dict[str, str]]): """Parser for output of router chain int he multi-prompt chain.""" default_destination: str = "DEFAULT" next_inputs_type: Type = str next_inputs_inner_key: str = "input" def parse(self, text: str) -> Dict[str, Any]: try:
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def parse(self, text: str) -> Dict[str, Any]: try: expected_keys = ["destination", "next_inputs"] parsed = parse_and_check_json_markdown(text, expected_keys) if not isinstance(parsed["destination"], str): raise ValueError("Expected 'destination' to be a string.") if not isinstance(parsed["next_inputs"], self.next_inputs_type): raise ValueError( f"Expected 'next_inputs' to be {self.next_inputs_type}." ) parsed["next_inputs"] = {self.next_inputs_inner_key: parsed["next_inputs"]} if ( parsed["destination"].strip().lower() == self.default_destination.lower() ): parsed["destination"] = None else: parsed["destination"] = parsed["destination"].strip() return parsed except Exception as e: raise OutputParserException( f"Parsing text\n{text}\n raised following error:\n{e}" )
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Source code for langchain.chains.conversational_retrieval.base """Chain for chatting with a vector database.""" from __future__ import annotations import warnings from abc import abstractmethod from pathlib import Path from typing import Any, Callable, Dict, List, Optional, Tuple, Union from pydantic import Extra, Field, root_validator from langchain.base_language import BaseLanguageModel from langchain.callbacks.manager import ( AsyncCallbackManagerForChainRun, CallbackManagerForChainRun, Callbacks, ) 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.conversational_retrieval.prompts import CONDENSE_QUESTION_PROMPT from langchain.chains.llm import LLMChain from langchain.chains.question_answering import load_qa_chain from langchain.prompts.base import BasePromptTemplate from langchain.schema import BaseMessage, BaseRetriever, Document from langchain.vectorstores.base import VectorStore # Depending on the memory type and configuration, the chat history format may differ. # This needs to be consolidated. CHAT_TURN_TYPE = Union[Tuple[str, str], BaseMessage] _ROLE_MAP = {"human": "Human: ", "ai": "Assistant: "} def _get_chat_history(chat_history: List[CHAT_TURN_TYPE]) -> str: buffer = "" for dialogue_turn in chat_history: if isinstance(dialogue_turn, BaseMessage): role_prefix = _ROLE_MAP.get(dialogue_turn.type, f"{dialogue_turn.type}: ") buffer += f"\n{role_prefix}{dialogue_turn.content}" elif isinstance(dialogue_turn, tuple): human = "Human: " + dialogue_turn[0]
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human = "Human: " + dialogue_turn[0] ai = "Assistant: " + dialogue_turn[1] buffer += "\n" + "\n".join([human, ai]) else: raise ValueError( f"Unsupported chat history format: {type(dialogue_turn)}." f" Full chat history: {chat_history} " ) return buffer class BaseConversationalRetrievalChain(Chain): """Chain for chatting with an index.""" combine_docs_chain: BaseCombineDocumentsChain question_generator: LLMChain output_key: str = "answer" return_source_documents: bool = False return_generated_question: bool = False get_chat_history: Optional[Callable[[CHAT_TURN_TYPE], str]] = None """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]: """Input keys.""" return ["question", "chat_history"] @property 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"] if self.return_generated_question: _output_keys = _output_keys + ["generated_question"] return _output_keys @abstractmethod def _get_docs(self, question: str, inputs: Dict[str, Any]) -> List[Document]: """Get docs.""" def _call( self,
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"""Get docs.""" def _call( self, inputs: Dict[str, Any], run_manager: Optional[CallbackManagerForChainRun] = None, ) -> Dict[str, Any]: _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager() question = inputs["question"] get_chat_history = self.get_chat_history or _get_chat_history chat_history_str = get_chat_history(inputs["chat_history"]) if chat_history_str: callbacks = _run_manager.get_child() new_question = self.question_generator.run( question=question, chat_history=chat_history_str, callbacks=callbacks ) else: new_question = question docs = self._get_docs(new_question, inputs) new_inputs = inputs.copy() new_inputs["question"] = new_question new_inputs["chat_history"] = chat_history_str answer = self.combine_docs_chain.run( input_documents=docs, callbacks=_run_manager.get_child(), **new_inputs ) output: Dict[str, Any] = {self.output_key: answer} if self.return_source_documents: output["source_documents"] = docs if self.return_generated_question: output["generated_question"] = new_question return output @abstractmethod async def _aget_docs(self, question: str, inputs: Dict[str, Any]) -> List[Document]: """Get docs.""" 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() question = inputs["question"]
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question = inputs["question"] get_chat_history = self.get_chat_history or _get_chat_history chat_history_str = get_chat_history(inputs["chat_history"]) if chat_history_str: callbacks = _run_manager.get_child() new_question = await self.question_generator.arun( question=question, chat_history=chat_history_str, callbacks=callbacks ) else: new_question = question docs = await self._aget_docs(new_question, inputs) new_inputs = inputs.copy() new_inputs["question"] = new_question new_inputs["chat_history"] = chat_history_str answer = await self.combine_docs_chain.arun( input_documents=docs, callbacks=_run_manager.get_child(), **new_inputs ) output: Dict[str, Any] = {self.output_key: answer} if self.return_source_documents: output["source_documents"] = docs if self.return_generated_question: output["generated_question"] = new_question return output def save(self, file_path: Union[Path, str]) -> None: if self.get_chat_history: raise ValueError("Chain not savable when `get_chat_history` is not None.") super().save(file_path) [docs]class ConversationalRetrievalChain(BaseConversationalRetrievalChain): """Chain for chatting with an index.""" retriever: BaseRetriever """Index to connect to.""" max_tokens_limit: Optional[int] = None """If set, restricts the docs to return from store based on tokens, enforced only for StuffDocumentChain""" def _reduce_tokens_below_limit(self, docs: List[Document]) -> List[Document]: num_docs = len(docs)
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num_docs = len(docs) if self.max_tokens_limit and isinstance( self.combine_docs_chain, StuffDocumentsChain ): tokens = [ self.combine_docs_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, question: str, inputs: Dict[str, Any]) -> List[Document]: docs = self.retriever.get_relevant_documents(question) return self._reduce_tokens_below_limit(docs) async def _aget_docs(self, question: str, inputs: Dict[str, Any]) -> List[Document]: docs = await self.retriever.aget_relevant_documents(question) return self._reduce_tokens_below_limit(docs) [docs] @classmethod def from_llm( cls, llm: BaseLanguageModel, retriever: BaseRetriever, condense_question_prompt: BasePromptTemplate = CONDENSE_QUESTION_PROMPT, chain_type: str = "stuff", verbose: bool = False, condense_question_llm: Optional[BaseLanguageModel] = None, combine_docs_chain_kwargs: Optional[Dict] = None, callbacks: Callbacks = None, **kwargs: Any, ) -> BaseConversationalRetrievalChain: """Load chain from LLM.""" combine_docs_chain_kwargs = combine_docs_chain_kwargs or {} doc_chain = load_qa_chain( llm, chain_type=chain_type, verbose=verbose, callbacks=callbacks,
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chain_type=chain_type, verbose=verbose, callbacks=callbacks, **combine_docs_chain_kwargs, ) _llm = condense_question_llm or llm condense_question_chain = LLMChain( llm=_llm, prompt=condense_question_prompt, verbose=verbose, callbacks=callbacks, ) return cls( retriever=retriever, combine_docs_chain=doc_chain, question_generator=condense_question_chain, callbacks=callbacks, **kwargs, ) [docs]class ChatVectorDBChain(BaseConversationalRetrievalChain): """Chain for chatting with a vector database.""" vectorstore: VectorStore = Field(alias="vectorstore") top_k_docs_for_context: int = 4 search_kwargs: dict = Field(default_factory=dict) @property def _chain_type(self) -> str: return "chat-vector-db" @root_validator() def raise_deprecation(cls, values: Dict) -> Dict: warnings.warn( "`ChatVectorDBChain` is deprecated - " "please use `from langchain.chains import ConversationalRetrievalChain`" ) return values def _get_docs(self, question: str, inputs: Dict[str, Any]) -> List[Document]: vectordbkwargs = inputs.get("vectordbkwargs", {}) full_kwargs = {**self.search_kwargs, **vectordbkwargs} return self.vectorstore.similarity_search( question, k=self.top_k_docs_for_context, **full_kwargs ) async def _aget_docs(self, question: str, inputs: Dict[str, Any]) -> List[Document]:
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raise NotImplementedError("ChatVectorDBChain does not support async") [docs] @classmethod def from_llm( cls, llm: BaseLanguageModel, vectorstore: VectorStore, condense_question_prompt: BasePromptTemplate = CONDENSE_QUESTION_PROMPT, chain_type: str = "stuff", combine_docs_chain_kwargs: Optional[Dict] = None, callbacks: Callbacks = None, **kwargs: Any, ) -> BaseConversationalRetrievalChain: """Load chain from LLM.""" combine_docs_chain_kwargs = combine_docs_chain_kwargs or {} doc_chain = load_qa_chain( llm, chain_type=chain_type, callbacks=callbacks, **combine_docs_chain_kwargs, ) condense_question_chain = LLMChain( llm=llm, prompt=condense_question_prompt, callbacks=callbacks ) return cls( vectorstore=vectorstore, combine_docs_chain=doc_chain, question_generator=condense_question_chain, callbacks=callbacks, **kwargs, )
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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 "
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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
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Source code for langchain.chains.graph_qa.cypher """Question answering over a graph.""" from __future__ import annotations import re from typing import Any, Dict, List, Optional from pydantic import Field from langchain.base_language import BaseLanguageModel from langchain.callbacks.manager import CallbackManagerForChainRun from langchain.chains.base import Chain from langchain.chains.graph_qa.prompts import CYPHER_GENERATION_PROMPT, CYPHER_QA_PROMPT from langchain.chains.llm import LLMChain from langchain.graphs.neo4j_graph import Neo4jGraph from langchain.prompts.base import BasePromptTemplate INTERMEDIATE_STEPS_KEY = "intermediate_steps" def extract_cypher(text: str) -> str: """ Extract Cypher code from a text. Args: text: Text to extract Cypher code from. Returns: Cypher code extracted from the text. """ # The pattern to find Cypher code enclosed in triple backticks pattern = r"```(.*?)```" # Find all matches in the input text matches = re.findall(pattern, text, re.DOTALL) return matches[0] if matches else text [docs]class GraphCypherQAChain(Chain): """Chain for question-answering against a graph by generating Cypher statements.""" graph: Neo4jGraph = Field(exclude=True) cypher_generation_chain: LLMChain qa_chain: LLMChain input_key: str = "query" #: :meta private: output_key: str = "result" #: :meta private: top_k: int = 10 """Number of results to return from the query"""
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"""Number of results to return from the query""" return_intermediate_steps: bool = False """Whether or not to return the intermediate steps along with the final answer.""" return_direct: bool = False """Whether or not to return the result of querying the graph directly.""" @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. :meta private: """ _output_keys = [self.output_key] return _output_keys @property def _chain_type(self) -> str: return "graph_cypher_chain" [docs] @classmethod def from_llm( cls, llm: BaseLanguageModel, *, qa_prompt: BasePromptTemplate = CYPHER_QA_PROMPT, cypher_prompt: BasePromptTemplate = CYPHER_GENERATION_PROMPT, **kwargs: Any, ) -> GraphCypherQAChain: """Initialize from LLM.""" qa_chain = LLMChain(llm=llm, prompt=qa_prompt) cypher_generation_chain = LLMChain(llm=llm, prompt=cypher_prompt) return cls( qa_chain=qa_chain, cypher_generation_chain=cypher_generation_chain, **kwargs, ) def _call( self, inputs: Dict[str, Any], run_manager: Optional[CallbackManagerForChainRun] = None, ) -> Dict[str, Any]:
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) -> Dict[str, Any]: """Generate Cypher statement, use it to look up in db and answer question.""" _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager() callbacks = _run_manager.get_child() question = inputs[self.input_key] intermediate_steps: List = [] generated_cypher = self.cypher_generation_chain.run( {"question": question, "schema": self.graph.get_schema}, callbacks=callbacks ) # Extract Cypher code if it is wrapped in backticks generated_cypher = extract_cypher(generated_cypher) _run_manager.on_text("Generated Cypher:", end="\n", verbose=self.verbose) _run_manager.on_text( generated_cypher, color="green", end="\n", verbose=self.verbose ) intermediate_steps.append({"query": generated_cypher}) # Retrieve and limit the number of results context = self.graph.query(generated_cypher)[: self.top_k] if self.return_direct: final_result = context else: _run_manager.on_text("Full Context:", end="\n", verbose=self.verbose) _run_manager.on_text( str(context), color="green", end="\n", verbose=self.verbose ) intermediate_steps.append({"context": context}) result = self.qa_chain( {"question": question, "context": context}, callbacks=callbacks, ) final_result = result[self.qa_chain.output_key] chain_result: Dict[str, Any] = {self.output_key: final_result} if self.return_intermediate_steps: chain_result[INTERMEDIATE_STEPS_KEY] = intermediate_steps return chain_result
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Source code for langchain.chains.graph_qa.nebulagraph """Question answering over a graph.""" from __future__ import annotations from typing import Any, Dict, List, Optional from pydantic import Field from langchain.base_language import BaseLanguageModel from langchain.callbacks.manager import CallbackManagerForChainRun from langchain.chains.base import Chain from langchain.chains.graph_qa.prompts import CYPHER_QA_PROMPT, NGQL_GENERATION_PROMPT from langchain.chains.llm import LLMChain from langchain.graphs.nebula_graph import NebulaGraph from langchain.prompts.base import BasePromptTemplate [docs]class NebulaGraphQAChain(Chain): """Chain for question-answering against a graph by generating nGQL statements.""" graph: NebulaGraph = Field(exclude=True) ngql_generation_chain: LLMChain qa_chain: LLMChain input_key: str = "query" #: :meta private: output_key: str = "result" #: :meta private: @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. :meta private: """ _output_keys = [self.output_key] return _output_keys [docs] @classmethod def from_llm( cls, llm: BaseLanguageModel, *, qa_prompt: BasePromptTemplate = CYPHER_QA_PROMPT, ngql_prompt: BasePromptTemplate = NGQL_GENERATION_PROMPT, **kwargs: Any,
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**kwargs: Any, ) -> NebulaGraphQAChain: """Initialize from LLM.""" qa_chain = LLMChain(llm=llm, prompt=qa_prompt) ngql_generation_chain = LLMChain(llm=llm, prompt=ngql_prompt) return cls( qa_chain=qa_chain, ngql_generation_chain=ngql_generation_chain, **kwargs, ) def _call( self, inputs: Dict[str, Any], run_manager: Optional[CallbackManagerForChainRun] = None, ) -> Dict[str, str]: """Generate nGQL statement, use it to look up in db and answer question.""" _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager() callbacks = _run_manager.get_child() question = inputs[self.input_key] generated_ngql = self.ngql_generation_chain.run( {"question": question, "schema": self.graph.get_schema}, callbacks=callbacks ) _run_manager.on_text("Generated nGQL:", end="\n", verbose=self.verbose) _run_manager.on_text( generated_ngql, color="green", end="\n", verbose=self.verbose ) context = self.graph.query(generated_ngql) _run_manager.on_text("Full Context:", end="\n", verbose=self.verbose) _run_manager.on_text( str(context), color="green", end="\n", verbose=self.verbose ) result = self.qa_chain( {"question": question, "context": context}, callbacks=callbacks, ) return {self.output_key: result[self.qa_chain.output_key]}
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Source code for langchain.chains.graph_qa.base """Question answering over a graph.""" from __future__ import annotations from typing import Any, Dict, List, Optional from pydantic import Field from langchain.base_language import BaseLanguageModel from langchain.callbacks.manager import CallbackManagerForChainRun from langchain.chains.base import Chain from langchain.chains.graph_qa.prompts import ENTITY_EXTRACTION_PROMPT, PROMPT from langchain.chains.llm import LLMChain from langchain.graphs.networkx_graph import NetworkxEntityGraph, get_entities from langchain.prompts.base import BasePromptTemplate [docs]class GraphQAChain(Chain): """Chain for question-answering against a graph.""" graph: NetworkxEntityGraph = Field(exclude=True) entity_extraction_chain: LLMChain qa_chain: LLMChain input_key: str = "query" #: :meta private: output_key: str = "result" #: :meta private: @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. :meta private: """ _output_keys = [self.output_key] return _output_keys [docs] @classmethod def from_llm( cls, llm: BaseLanguageModel, qa_prompt: BasePromptTemplate = PROMPT, entity_prompt: BasePromptTemplate = ENTITY_EXTRACTION_PROMPT, **kwargs: Any, ) -> GraphQAChain: """Initialize from LLM."""
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) -> GraphQAChain: """Initialize from LLM.""" qa_chain = LLMChain(llm=llm, prompt=qa_prompt) entity_chain = LLMChain(llm=llm, prompt=entity_prompt) return cls( qa_chain=qa_chain, entity_extraction_chain=entity_chain, **kwargs, ) def _call( self, inputs: Dict[str, Any], run_manager: Optional[CallbackManagerForChainRun] = None, ) -> Dict[str, str]: """Extract entities, look up info and answer question.""" _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager() question = inputs[self.input_key] entity_string = self.entity_extraction_chain.run(question) _run_manager.on_text("Entities Extracted:", end="\n", verbose=self.verbose) _run_manager.on_text( entity_string, color="green", end="\n", verbose=self.verbose ) entities = get_entities(entity_string) context = "" for entity in entities: triplets = self.graph.get_entity_knowledge(entity) context += "\n".join(triplets) _run_manager.on_text("Full Context:", end="\n", verbose=self.verbose) _run_manager.on_text(context, color="green", end="\n", verbose=self.verbose) result = self.qa_chain( {"question": question, "context": context}, callbacks=_run_manager.get_child(), ) return {self.output_key: result[self.qa_chain.output_key]}
https://api.python.langchain.com/en/stable/_modules/langchain/chains/graph_qa/base.html
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Source code for langchain.chains.graph_qa.kuzu """Question answering over a graph.""" from __future__ import annotations from typing import Any, Dict, List, Optional from pydantic import Field from langchain.base_language import BaseLanguageModel from langchain.callbacks.manager import CallbackManagerForChainRun from langchain.chains.base import Chain from langchain.chains.graph_qa.prompts import CYPHER_QA_PROMPT, KUZU_GENERATION_PROMPT from langchain.chains.llm import LLMChain from langchain.graphs.kuzu_graph import KuzuGraph from langchain.prompts.base import BasePromptTemplate [docs]class KuzuQAChain(Chain): """Chain for question-answering against a graph by generating Cypher statements for Kùzu. """ graph: KuzuGraph = Field(exclude=True) cypher_generation_chain: LLMChain qa_chain: LLMChain input_key: str = "query" #: :meta private: output_key: str = "result" #: :meta private: @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. :meta private: """ _output_keys = [self.output_key] return _output_keys [docs] @classmethod def from_llm( cls, llm: BaseLanguageModel, *, qa_prompt: BasePromptTemplate = CYPHER_QA_PROMPT, cypher_prompt: BasePromptTemplate = KUZU_GENERATION_PROMPT,
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cypher_prompt: BasePromptTemplate = KUZU_GENERATION_PROMPT, **kwargs: Any, ) -> KuzuQAChain: """Initialize from LLM.""" qa_chain = LLMChain(llm=llm, prompt=qa_prompt) cypher_generation_chain = LLMChain(llm=llm, prompt=cypher_prompt) return cls( qa_chain=qa_chain, cypher_generation_chain=cypher_generation_chain, **kwargs, ) def _call( self, inputs: Dict[str, Any], run_manager: Optional[CallbackManagerForChainRun] = None, ) -> Dict[str, str]: """Generate Cypher statement, use it to look up in db and answer question.""" _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager() callbacks = _run_manager.get_child() question = inputs[self.input_key] generated_cypher = self.cypher_generation_chain.run( {"question": question, "schema": self.graph.get_schema}, callbacks=callbacks ) _run_manager.on_text("Generated Cypher:", end="\n", verbose=self.verbose) _run_manager.on_text( generated_cypher, color="green", end="\n", verbose=self.verbose ) context = self.graph.query(generated_cypher) _run_manager.on_text("Full Context:", end="\n", verbose=self.verbose) _run_manager.on_text( str(context), color="green", end="\n", verbose=self.verbose ) result = self.qa_chain( {"question": question, "context": context}, callbacks=callbacks, )
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callbacks=callbacks, ) return {self.output_key: result[self.qa_chain.output_key]}
https://api.python.langchain.com/en/stable/_modules/langchain/chains/graph_qa/kuzu.html
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Source code for langchain.chains.openai_functions.qa_with_structure from typing import Any, List, Optional, Type, Union from pydantic import BaseModel, Field from langchain.base_language import BaseLanguageModel from langchain.chains.llm import LLMChain from langchain.chains.openai_functions.utils import get_llm_kwargs from langchain.output_parsers.openai_functions import ( OutputFunctionsParser, PydanticOutputFunctionsParser, ) from langchain.prompts import PromptTemplate from langchain.prompts.chat import ChatPromptTemplate, HumanMessagePromptTemplate from langchain.schema import BaseLLMOutputParser, HumanMessage, SystemMessage class AnswerWithSources(BaseModel): """An answer to the question being asked, with sources.""" answer: str = Field(..., description="Answer to the question that was asked") sources: List[str] = Field( ..., description="List of sources used to answer the question" ) [docs]def create_qa_with_structure_chain( llm: BaseLanguageModel, schema: Union[dict, Type[BaseModel]], output_parser: str = "base", prompt: Optional[Union[PromptTemplate, ChatPromptTemplate]] = None, ) -> LLMChain: """Create a question answering chain that returns an answer with sources. Args: llm: Language model to use for the chain. schema: Pydantic schema to use for the output. output_parser: Output parser to use. Should be one of `pydantic` or `base`. Default to `base`. prompt: Optional prompt to use for the chain. Returns: """ if output_parser == "pydantic":
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Returns: """ if output_parser == "pydantic": if not (isinstance(schema, type) and issubclass(schema, BaseModel)): raise ValueError( "Must provide a pydantic class for schema when output_parser is " "'pydantic'." ) _output_parser: BaseLLMOutputParser = PydanticOutputFunctionsParser( pydantic_schema=schema ) elif output_parser == "base": _output_parser = OutputFunctionsParser() else: raise ValueError( f"Got unexpected output_parser: {output_parser}. " f"Should be one of `pydantic` or `base`." ) if isinstance(schema, type) and issubclass(schema, BaseModel): schema_dict = schema.schema() else: schema_dict = schema function = { "name": schema_dict["title"], "description": schema_dict["description"], "parameters": schema_dict, } llm_kwargs = get_llm_kwargs(function) messages = [ SystemMessage( content=( "You are a world class algorithm to answer " "questions in a specific format." ) ), HumanMessage(content="Answer question using the following context"), HumanMessagePromptTemplate.from_template("{context}"), HumanMessagePromptTemplate.from_template("Question: {question}"), HumanMessage(content="Tips: Make sure to answer in the correct format"), ] prompt = prompt or ChatPromptTemplate(messages=messages) chain = LLMChain( llm=llm, prompt=prompt, llm_kwargs=llm_kwargs, output_parser=_output_parser, )
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output_parser=_output_parser, ) return chain [docs]def create_qa_with_sources_chain(llm: BaseLanguageModel, **kwargs: Any) -> LLMChain: """Create a question answering chain that returns an answer with sources. Args: llm: Language model to use for the chain. **kwargs: Keyword arguments to pass to `create_qa_with_structure_chain`. Returns: Chain (LLMChain) that can be used to answer questions with citations. """ return create_qa_with_structure_chain(llm, AnswerWithSources, **kwargs)
https://api.python.langchain.com/en/stable/_modules/langchain/chains/openai_functions/qa_with_structure.html
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Source code for langchain.chains.openai_functions.citation_fuzzy_match from typing import Iterator, List from pydantic import BaseModel, Field from langchain.base_language import BaseLanguageModel from langchain.chains.llm import LLMChain from langchain.chains.openai_functions.utils import get_llm_kwargs from langchain.output_parsers.openai_functions import ( PydanticOutputFunctionsParser, ) from langchain.prompts.chat import ChatPromptTemplate, HumanMessagePromptTemplate from langchain.schema import HumanMessage, SystemMessage class FactWithEvidence(BaseModel): """Class representing single statement. Each fact has a body and a list of sources. If there are multiple facts make sure to break them apart such that each one only uses a set of sources that are relevant to it. """ fact: str = Field(..., description="Body of the sentence, as part of a response") substring_quote: List[str] = Field( ..., description=( "Each source should be a direct quote from the context, " "as a substring of the original content" ), ) def _get_span(self, quote: str, context: str, errs: int = 100) -> Iterator[str]: import regex minor = quote major = context errs_ = 0 s = regex.search(f"({minor}){{e<={errs_}}}", major) while s is None and errs_ <= errs: errs_ += 1 s = regex.search(f"({minor}){{e<={errs_}}}", major) if s is not None: yield from s.spans() def get_spans(self, context: str) -> Iterator[str]:
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def get_spans(self, context: str) -> Iterator[str]: for quote in self.substring_quote: yield from self._get_span(quote, context) class QuestionAnswer(BaseModel): """A question and its answer as a list of facts each one should have a source. each sentence contains a body and a list of sources.""" question: str = Field(..., description="Question that was asked") answer: List[FactWithEvidence] = Field( ..., description=( "Body of the answer, each fact should be " "its separate object with a body and a list of sources" ), ) [docs]def create_citation_fuzzy_match_chain(llm: BaseLanguageModel) -> LLMChain: """Create a citation fuzzy match chain. Args: llm: Language model to use for the chain. Returns: Chain (LLMChain) that can be used to answer questions with citations. """ output_parser = PydanticOutputFunctionsParser(pydantic_schema=QuestionAnswer) schema = QuestionAnswer.schema() function = { "name": schema["title"], "description": schema["description"], "parameters": schema, } llm_kwargs = get_llm_kwargs(function) messages = [ SystemMessage( content=( "You are a world class algorithm to answer " "questions with correct and exact citations." ) ), HumanMessage(content="Answer question using the following context"), HumanMessagePromptTemplate.from_template("{context}"), HumanMessagePromptTemplate.from_template("Question: {question}"), HumanMessage( content=( "Tips: Make sure to cite your sources, "
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content=( "Tips: Make sure to cite your sources, " "and use the exact words from the context." ) ), ] prompt = ChatPromptTemplate(messages=messages) chain = LLMChain( llm=llm, prompt=prompt, llm_kwargs=llm_kwargs, output_parser=output_parser, ) return chain
https://api.python.langchain.com/en/stable/_modules/langchain/chains/openai_functions/citation_fuzzy_match.html
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Source code for langchain.chains.openai_functions.tagging from typing import Any from langchain.base_language import BaseLanguageModel from langchain.chains.base import Chain from langchain.chains.llm import LLMChain from langchain.chains.openai_functions.utils import _convert_schema, get_llm_kwargs from langchain.output_parsers.openai_functions import ( JsonOutputFunctionsParser, PydanticOutputFunctionsParser, ) from langchain.prompts import ChatPromptTemplate def _get_tagging_function(schema: dict) -> dict: return { "name": "information_extraction", "description": "Extracts the relevant information from the passage.", "parameters": _convert_schema(schema), } _TAGGING_TEMPLATE = """Extract the desired information from the following passage. Passage: {input} """ [docs]def create_tagging_chain(schema: dict, llm: BaseLanguageModel) -> Chain: """Creates a chain that extracts information from a passage. Args: schema: The schema of the entities to extract. llm: The language model to use. Returns: Chain (LLMChain) that can be used to extract information from a passage. """ function = _get_tagging_function(schema) prompt = ChatPromptTemplate.from_template(_TAGGING_TEMPLATE) output_parser = JsonOutputFunctionsParser() llm_kwargs = get_llm_kwargs(function) chain = LLMChain( llm=llm, prompt=prompt, llm_kwargs=llm_kwargs, output_parser=output_parser, ) return chain [docs]def create_tagging_chain_pydantic( pydantic_schema: Any, llm: BaseLanguageModel
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pydantic_schema: Any, llm: BaseLanguageModel ) -> Chain: """Creates a chain that extracts information from a passage. Args: pydantic_schema: The pydantic schema of the entities to extract. llm: The language model to use. Returns: Chain (LLMChain) that can be used to extract information from a passage. """ openai_schema = pydantic_schema.schema() function = _get_tagging_function(openai_schema) prompt = ChatPromptTemplate.from_template(_TAGGING_TEMPLATE) output_parser = PydanticOutputFunctionsParser(pydantic_schema=pydantic_schema) llm_kwargs = get_llm_kwargs(function) chain = LLMChain( llm=llm, prompt=prompt, llm_kwargs=llm_kwargs, output_parser=output_parser, ) return chain
https://api.python.langchain.com/en/stable/_modules/langchain/chains/openai_functions/tagging.html
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Source code for langchain.chains.openai_functions.extraction from typing import Any, List from pydantic import BaseModel from langchain.base_language import BaseLanguageModel from langchain.chains.base import Chain from langchain.chains.llm import LLMChain from langchain.chains.openai_functions.utils import ( _convert_schema, _resolve_schema_references, get_llm_kwargs, ) from langchain.output_parsers.openai_functions import ( JsonKeyOutputFunctionsParser, PydanticAttrOutputFunctionsParser, ) from langchain.prompts import ChatPromptTemplate def _get_extraction_function(entity_schema: dict) -> dict: return { "name": "information_extraction", "description": "Extracts the relevant information from the passage.", "parameters": { "type": "object", "properties": { "info": {"type": "array", "items": _convert_schema(entity_schema)} }, "required": ["info"], }, } _EXTRACTION_TEMPLATE = """Extract and save the relevant entities mentioned\ in the following passage together with their properties. Passage: {input} """ [docs]def create_extraction_chain(schema: dict, llm: BaseLanguageModel) -> Chain: """Creates a chain that extracts information from a passage. Args: schema: The schema of the entities to extract. llm: The language model to use. Returns: Chain that can be used to extract information from a passage. """ function = _get_extraction_function(schema) prompt = ChatPromptTemplate.from_template(_EXTRACTION_TEMPLATE) output_parser = JsonKeyOutputFunctionsParser(key_name="info")
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output_parser = JsonKeyOutputFunctionsParser(key_name="info") llm_kwargs = get_llm_kwargs(function) chain = LLMChain( llm=llm, prompt=prompt, llm_kwargs=llm_kwargs, output_parser=output_parser, ) return chain [docs]def create_extraction_chain_pydantic( pydantic_schema: Any, llm: BaseLanguageModel ) -> Chain: """Creates a chain that extracts information from a passage using pydantic schema. Args: pydantic_schema: The pydantic schema of the entities to extract. llm: The language model to use. Returns: Chain that can be used to extract information from a passage. """ class PydanticSchema(BaseModel): info: List[pydantic_schema] # type: ignore openai_schema = pydantic_schema.schema() openai_schema = _resolve_schema_references( openai_schema, openai_schema.get("definitions", {}) ) function = _get_extraction_function(openai_schema) prompt = ChatPromptTemplate.from_template(_EXTRACTION_TEMPLATE) output_parser = PydanticAttrOutputFunctionsParser( pydantic_schema=PydanticSchema, attr_name="info" ) llm_kwargs = get_llm_kwargs(function) chain = LLMChain( llm=llm, prompt=prompt, llm_kwargs=llm_kwargs, output_parser=output_parser, ) return chain
https://api.python.langchain.com/en/stable/_modules/langchain/chains/openai_functions/extraction.html
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Source code for langchain.chains.llm_checker.base """Chain for question-answering with self-verification.""" from __future__ import annotations import warnings from typing import Any, Dict, List, Optional from pydantic import Extra, root_validator from langchain.base_language import BaseLanguageModel from langchain.callbacks.manager import CallbackManagerForChainRun from langchain.chains.base import Chain from langchain.chains.llm import LLMChain from langchain.chains.llm_checker.prompt import ( CHECK_ASSERTIONS_PROMPT, CREATE_DRAFT_ANSWER_PROMPT, LIST_ASSERTIONS_PROMPT, REVISED_ANSWER_PROMPT, ) from langchain.chains.sequential import SequentialChain from langchain.prompts import PromptTemplate def _load_question_to_checked_assertions_chain( llm: BaseLanguageModel, create_draft_answer_prompt: PromptTemplate, list_assertions_prompt: PromptTemplate, check_assertions_prompt: PromptTemplate, revised_answer_prompt: PromptTemplate, ) -> SequentialChain: create_draft_answer_chain = LLMChain( llm=llm, prompt=create_draft_answer_prompt, output_key="statement", ) list_assertions_chain = LLMChain( llm=llm, prompt=list_assertions_prompt, output_key="assertions", ) check_assertions_chain = LLMChain( llm=llm, prompt=check_assertions_prompt, output_key="checked_assertions", ) revised_answer_chain = LLMChain( llm=llm, prompt=revised_answer_prompt, output_key="revised_statement", ) chains = [ create_draft_answer_chain,
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) chains = [ create_draft_answer_chain, list_assertions_chain, check_assertions_chain, revised_answer_chain, ] question_to_checked_assertions_chain = SequentialChain( chains=chains, input_variables=["question"], output_variables=["revised_statement"], verbose=True, ) return question_to_checked_assertions_chain [docs]class LLMCheckerChain(Chain): """Chain for question-answering with self-verification. Example: .. code-block:: python from langchain import OpenAI, LLMCheckerChain llm = OpenAI(temperature=0.7) checker_chain = LLMCheckerChain.from_llm(llm) """ question_to_checked_assertions_chain: SequentialChain llm: Optional[BaseLanguageModel] = None """[Deprecated] LLM wrapper to use.""" create_draft_answer_prompt: PromptTemplate = CREATE_DRAFT_ANSWER_PROMPT """[Deprecated]""" list_assertions_prompt: PromptTemplate = LIST_ASSERTIONS_PROMPT """[Deprecated]""" check_assertions_prompt: PromptTemplate = CHECK_ASSERTIONS_PROMPT """[Deprecated]""" revised_answer_prompt: PromptTemplate = REVISED_ANSWER_PROMPT """[Deprecated] Prompt to use when questioning the documents.""" input_key: str = "query" #: :meta private: output_key: str = "result" #: :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:
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if "llm" in values: warnings.warn( "Directly instantiating an LLMCheckerChain with an llm is deprecated. " "Please instantiate with question_to_checked_assertions_chain " "or using the from_llm class method." ) if ( "question_to_checked_assertions_chain" not in values and values["llm"] is not None ): question_to_checked_assertions_chain = ( _load_question_to_checked_assertions_chain( values["llm"], values.get( "create_draft_answer_prompt", CREATE_DRAFT_ANSWER_PROMPT ), values.get("list_assertions_prompt", LIST_ASSERTIONS_PROMPT), values.get("check_assertions_prompt", CHECK_ASSERTIONS_PROMPT), values.get("revised_answer_prompt", REVISED_ANSWER_PROMPT), ) ) values[ "question_to_checked_assertions_chain" ] = question_to_checked_assertions_chain return values @property def input_keys(self) -> List[str]: """Return the singular input key. :meta private: """ return [self.input_key] @property def output_keys(self) -> List[str]: """Return the singular output key. :meta private: """ return [self.output_key] 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.input_key] output = self.question_to_checked_assertions_chain(
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output = self.question_to_checked_assertions_chain( {"question": question}, callbacks=_run_manager.get_child() ) return {self.output_key: output["revised_statement"]} @property def _chain_type(self) -> str: return "llm_checker_chain" [docs] @classmethod def from_llm( cls, llm: BaseLanguageModel, create_draft_answer_prompt: PromptTemplate = CREATE_DRAFT_ANSWER_PROMPT, list_assertions_prompt: PromptTemplate = LIST_ASSERTIONS_PROMPT, check_assertions_prompt: PromptTemplate = CHECK_ASSERTIONS_PROMPT, revised_answer_prompt: PromptTemplate = REVISED_ANSWER_PROMPT, **kwargs: Any, ) -> LLMCheckerChain: question_to_checked_assertions_chain = ( _load_question_to_checked_assertions_chain( llm, create_draft_answer_prompt, list_assertions_prompt, check_assertions_prompt, revised_answer_prompt, ) ) return cls( question_to_checked_assertions_chain=question_to_checked_assertions_chain, **kwargs, )
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Source code for langchain.chains.combine_documents.stuff """Chain that combines documents by stuffing into context.""" from typing import Any, Dict, List, Optional, Tuple from pydantic import Extra, Field, root_validator from langchain.callbacks.manager import Callbacks from langchain.chains.combine_documents.base import ( BaseCombineDocumentsChain, format_document, ) from langchain.chains.llm import LLMChain from langchain.docstore.document import Document from langchain.prompts.base import BasePromptTemplate from langchain.prompts.prompt import PromptTemplate def _get_default_document_prompt() -> PromptTemplate: return PromptTemplate(input_variables=["page_content"], template="{page_content}") [docs]class StuffDocumentsChain(BaseCombineDocumentsChain): """Chain that combines documents by stuffing into context.""" llm_chain: LLMChain """LLM wrapper to use after formatting documents.""" document_prompt: BasePromptTemplate = Field( default_factory=_get_default_document_prompt ) """Prompt to use to format each document.""" document_variable_name: str """The variable name in the llm_chain to put the documents in. If only one variable in the llm_chain, this need not be provided.""" document_separator: str = "\n\n" """The string with which to join the formatted documents""" class Config: """Configuration for this pydantic object.""" extra = Extra.forbid arbitrary_types_allowed = True @root_validator(pre=True) def get_default_document_variable_name(cls, values: Dict) -> Dict: """Get default document variable name, if not provided.""" llm_chain_variables = values["llm_chain"].prompt.input_variables if "document_variable_name" not in values:
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if "document_variable_name" not in values: if len(llm_chain_variables) == 1: values["document_variable_name"] = llm_chain_variables[0] else: raise ValueError( "document_variable_name must be provided if there are " "multiple llm_chain_variables" ) else: if values["document_variable_name"] not in llm_chain_variables: raise ValueError( f"document_variable_name {values['document_variable_name']} was " f"not found in llm_chain input_variables: {llm_chain_variables}" ) return values def _get_inputs(self, docs: List[Document], **kwargs: Any) -> dict: # Format each document according to the prompt doc_strings = [format_document(doc, self.document_prompt) for doc in docs] # Join the documents together to put them in the prompt. inputs = { k: v for k, v in kwargs.items() if k in self.llm_chain.prompt.input_variables } inputs[self.document_variable_name] = self.document_separator.join(doc_strings) return inputs [docs] def prompt_length(self, docs: List[Document], **kwargs: Any) -> Optional[int]: """Get the prompt length by formatting the prompt.""" inputs = self._get_inputs(docs, **kwargs) prompt = self.llm_chain.prompt.format(**inputs) return self.llm_chain.llm.get_num_tokens(prompt) [docs] def combine_docs( self, docs: List[Document], callbacks: Callbacks = None, **kwargs: Any ) -> Tuple[str, dict]: """Stuff all documents into one prompt and pass to LLM."""
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"""Stuff all documents into one prompt and pass to LLM.""" inputs = self._get_inputs(docs, **kwargs) # Call predict on the LLM. return self.llm_chain.predict(callbacks=callbacks, **inputs), {} [docs] async def acombine_docs( self, docs: List[Document], callbacks: Callbacks = None, **kwargs: Any ) -> Tuple[str, dict]: """Stuff all documents into one prompt and pass to LLM.""" inputs = self._get_inputs(docs, **kwargs) # Call predict on the LLM. return await self.llm_chain.apredict(callbacks=callbacks, **inputs), {} @property def _chain_type(self) -> str: return "stuff_documents_chain"
https://api.python.langchain.com/en/stable/_modules/langchain/chains/combine_documents/stuff.html
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Source code for langchain.chains.combine_documents.refine """Combining documents by doing a first pass and then refining on more documents.""" from __future__ import annotations from typing import Any, Dict, List, Tuple from pydantic import Extra, Field, root_validator from langchain.callbacks.manager import Callbacks from langchain.chains.combine_documents.base import ( BaseCombineDocumentsChain, format_document, ) from langchain.chains.llm import LLMChain from langchain.docstore.document import Document from langchain.prompts.base import BasePromptTemplate from langchain.prompts.prompt import PromptTemplate def _get_default_document_prompt() -> PromptTemplate: return PromptTemplate(input_variables=["page_content"], template="{page_content}") [docs]class RefineDocumentsChain(BaseCombineDocumentsChain): """Combine documents by doing a first pass and then refining on more documents.""" initial_llm_chain: LLMChain """LLM chain to use on initial document.""" refine_llm_chain: LLMChain """LLM chain to use when refining.""" document_variable_name: str """The variable name in the initial_llm_chain to put the documents in. If only one variable in the initial_llm_chain, this need not be provided.""" initial_response_name: str """The variable name to format the initial response in when refining.""" document_prompt: BasePromptTemplate = Field( default_factory=_get_default_document_prompt ) """Prompt to use to format each document.""" return_intermediate_steps: bool = False """Return the results of the refine steps in the output.""" @property def output_keys(self) -> List[str]: """Expect input key. :meta private: """
https://api.python.langchain.com/en/stable/_modules/langchain/chains/combine_documents/refine.html
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"""Expect input key. :meta private: """ _output_keys = super().output_keys if self.return_intermediate_steps: _output_keys = _output_keys + ["intermediate_steps"] return _output_keys class Config: """Configuration for this pydantic object.""" extra = Extra.forbid arbitrary_types_allowed = True @root_validator(pre=True) def get_return_intermediate_steps(cls, values: Dict) -> Dict: """For backwards compatibility.""" if "return_refine_steps" in values: values["return_intermediate_steps"] = values["return_refine_steps"] del values["return_refine_steps"] return values @root_validator(pre=True) def get_default_document_variable_name(cls, values: Dict) -> Dict: """Get default document variable name, if not provided.""" if "document_variable_name" not in values: llm_chain_variables = values["initial_llm_chain"].prompt.input_variables if len(llm_chain_variables) == 1: values["document_variable_name"] = llm_chain_variables[0] else: raise ValueError( "document_variable_name must be provided if there are " "multiple llm_chain input_variables" ) else: llm_chain_variables = values["initial_llm_chain"].prompt.input_variables if values["document_variable_name"] not in llm_chain_variables: raise ValueError( f"document_variable_name {values['document_variable_name']} was " f"not found in llm_chain input_variables: {llm_chain_variables}" ) return values [docs] def combine_docs(
https://api.python.langchain.com/en/stable/_modules/langchain/chains/combine_documents/refine.html
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) return values [docs] def combine_docs( self, docs: List[Document], callbacks: Callbacks = None, **kwargs: Any ) -> Tuple[str, dict]: """Combine by mapping first chain over all, then stuffing into final chain.""" inputs = self._construct_initial_inputs(docs, **kwargs) res = self.initial_llm_chain.predict(callbacks=callbacks, **inputs) refine_steps = [res] for doc in docs[1:]: base_inputs = self._construct_refine_inputs(doc, res) inputs = {**base_inputs, **kwargs} res = self.refine_llm_chain.predict(callbacks=callbacks, **inputs) refine_steps.append(res) return self._construct_result(refine_steps, res) [docs] async def acombine_docs( self, docs: List[Document], callbacks: Callbacks = None, **kwargs: Any ) -> Tuple[str, dict]: """Combine by mapping first chain over all, then stuffing into final chain.""" inputs = self._construct_initial_inputs(docs, **kwargs) res = await self.initial_llm_chain.apredict(callbacks=callbacks, **inputs) refine_steps = [res] for doc in docs[1:]: base_inputs = self._construct_refine_inputs(doc, res) inputs = {**base_inputs, **kwargs} res = await self.refine_llm_chain.apredict(callbacks=callbacks, **inputs) refine_steps.append(res) return self._construct_result(refine_steps, res) def _construct_result(self, refine_steps: List[str], res: str) -> Tuple[str, dict]: if self.return_intermediate_steps:
https://api.python.langchain.com/en/stable/_modules/langchain/chains/combine_documents/refine.html
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if self.return_intermediate_steps: extra_return_dict = {"intermediate_steps": refine_steps} else: extra_return_dict = {} return res, extra_return_dict def _construct_refine_inputs(self, doc: Document, res: str) -> Dict[str, Any]: return { self.document_variable_name: format_document(doc, self.document_prompt), self.initial_response_name: res, } def _construct_initial_inputs( self, docs: List[Document], **kwargs: Any ) -> Dict[str, Any]: base_info = {"page_content": docs[0].page_content} base_info.update(docs[0].metadata) document_info = {k: base_info[k] for k in self.document_prompt.input_variables} base_inputs: dict = { self.document_variable_name: self.document_prompt.format(**document_info) } inputs = {**base_inputs, **kwargs} return inputs @property def _chain_type(self) -> str: return "refine_documents_chain"
https://api.python.langchain.com/en/stable/_modules/langchain/chains/combine_documents/refine.html
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Source code for langchain.chains.combine_documents.map_rerank """Combining documents by mapping a chain over them first, then reranking results.""" from __future__ import annotations from typing import Any, Dict, List, Optional, Sequence, Tuple, Union, cast from pydantic import Extra, root_validator from langchain.callbacks.manager import Callbacks from langchain.chains.combine_documents.base import BaseCombineDocumentsChain from langchain.chains.llm import LLMChain from langchain.docstore.document import Document from langchain.output_parsers.regex import RegexParser [docs]class MapRerankDocumentsChain(BaseCombineDocumentsChain): """Combining documents by mapping a chain over them, then reranking results.""" llm_chain: LLMChain """Chain to apply to each document individually.""" document_variable_name: str """The variable name in the llm_chain to put the documents in. If only one variable in the llm_chain, this need not be provided.""" rank_key: str """Key in output of llm_chain to rank on.""" answer_key: str """Key in output of llm_chain to return as answer.""" metadata_keys: Optional[List[str]] = None return_intermediate_steps: bool = False class Config: """Configuration for this pydantic object.""" extra = Extra.forbid arbitrary_types_allowed = True @property def output_keys(self) -> List[str]: """Expect input key. :meta private: """ _output_keys = super().output_keys if self.return_intermediate_steps: _output_keys = _output_keys + ["intermediate_steps"] if self.metadata_keys is not None: _output_keys += self.metadata_keys return _output_keys
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_output_keys += self.metadata_keys return _output_keys @root_validator() def validate_llm_output(cls, values: Dict) -> Dict: """Validate that the combine chain outputs a dictionary.""" output_parser = values["llm_chain"].prompt.output_parser if not isinstance(output_parser, RegexParser): raise ValueError( "Output parser of llm_chain should be a RegexParser," f" got {output_parser}" ) output_keys = output_parser.output_keys if values["rank_key"] not in output_keys: raise ValueError( f"Got {values['rank_key']} as key to rank on, but did not find " f"it in the llm_chain output keys ({output_keys})" ) if values["answer_key"] not in output_keys: raise ValueError( f"Got {values['answer_key']} as key to return, but did not find " f"it in the llm_chain output keys ({output_keys})" ) return values @root_validator(pre=True) def get_default_document_variable_name(cls, values: Dict) -> Dict: """Get default document variable name, if not provided.""" if "document_variable_name" not in values: llm_chain_variables = values["llm_chain"].prompt.input_variables if len(llm_chain_variables) == 1: values["document_variable_name"] = llm_chain_variables[0] else: raise ValueError( "document_variable_name must be provided if there are " "multiple llm_chain input_variables" ) else: llm_chain_variables = values["llm_chain"].prompt.input_variables
https://api.python.langchain.com/en/stable/_modules/langchain/chains/combine_documents/map_rerank.html
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else: llm_chain_variables = values["llm_chain"].prompt.input_variables if values["document_variable_name"] not in llm_chain_variables: raise ValueError( f"document_variable_name {values['document_variable_name']} was " f"not found in llm_chain input_variables: {llm_chain_variables}" ) return values [docs] def combine_docs( self, docs: List[Document], callbacks: Callbacks = None, **kwargs: Any ) -> Tuple[str, dict]: """Combine documents in a map rerank manner. Combine by mapping first chain over all documents, then reranking the results. """ results = self.llm_chain.apply_and_parse( # FYI - this is parallelized and so it is fast. [{**{self.document_variable_name: d.page_content}, **kwargs} for d in docs], callbacks=callbacks, ) return self._process_results(docs, results) [docs] async def acombine_docs( self, docs: List[Document], callbacks: Callbacks = None, **kwargs: Any ) -> Tuple[str, dict]: """Combine documents in a map rerank manner. Combine by mapping first chain over all documents, then reranking the results. """ results = await self.llm_chain.aapply_and_parse( # FYI - this is parallelized and so it is fast. [{**{self.document_variable_name: d.page_content}, **kwargs} for d in docs], callbacks=callbacks, ) return self._process_results(docs, results) def _process_results( self, docs: List[Document],
https://api.python.langchain.com/en/stable/_modules/langchain/chains/combine_documents/map_rerank.html
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def _process_results( self, docs: List[Document], results: Sequence[Union[str, List[str], Dict[str, str]]], ) -> Tuple[str, dict]: typed_results = cast(List[dict], results) sorted_res = sorted( zip(typed_results, docs), key=lambda x: -int(x[0][self.rank_key]) ) output, document = sorted_res[0] extra_info = {} if self.metadata_keys is not None: for key in self.metadata_keys: extra_info[key] = document.metadata[key] if self.return_intermediate_steps: extra_info["intermediate_steps"] = results return output[self.answer_key], extra_info @property def _chain_type(self) -> str: return "map_rerank_documents_chain"
https://api.python.langchain.com/en/stable/_modules/langchain/chains/combine_documents/map_rerank.html
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Source code for langchain.chains.combine_documents.base """Base interface for chains combining documents.""" from abc import ABC, abstractmethod from typing import Any, Dict, List, Optional, Tuple from pydantic import Field from langchain.callbacks.manager import ( AsyncCallbackManagerForChainRun, CallbackManagerForChainRun, ) from langchain.chains.base import Chain from langchain.docstore.document import Document from langchain.prompts.base import BasePromptTemplate from langchain.text_splitter import RecursiveCharacterTextSplitter, TextSplitter def format_document(doc: Document, prompt: BasePromptTemplate) -> str: """Format a document into a string based on a prompt template.""" base_info = {"page_content": doc.page_content} base_info.update(doc.metadata) missing_metadata = set(prompt.input_variables).difference(base_info) if len(missing_metadata) > 0: required_metadata = [ iv for iv in prompt.input_variables if iv != "page_content" ] raise ValueError( f"Document prompt requires documents to have metadata variables: " f"{required_metadata}. Received document with missing metadata: " f"{list(missing_metadata)}." ) document_info = {k: base_info[k] for k in prompt.input_variables} return prompt.format(**document_info) class BaseCombineDocumentsChain(Chain, ABC): """Base interface for chains combining documents.""" input_key: str = "input_documents" #: :meta private: output_key: str = "output_text" #: :meta private: @property def input_keys(self) -> List[str]: """Expect input key. :meta private: """ return [self.input_key] @property
https://api.python.langchain.com/en/stable/_modules/langchain/chains/combine_documents/base.html
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""" return [self.input_key] @property def output_keys(self) -> List[str]: """Return output key. :meta private: """ return [self.output_key] def prompt_length(self, docs: List[Document], **kwargs: Any) -> Optional[int]: """Return the prompt length given the documents passed in. Returns None if the method does not depend on the prompt length. """ return None @abstractmethod def combine_docs(self, docs: List[Document], **kwargs: Any) -> Tuple[str, dict]: """Combine documents into a single string.""" @abstractmethod async def acombine_docs( self, docs: List[Document], **kwargs: Any ) -> Tuple[str, dict]: """Combine documents into a single string asynchronously.""" def _call( self, inputs: Dict[str, List[Document]], run_manager: Optional[CallbackManagerForChainRun] = None, ) -> Dict[str, str]: _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager() docs = inputs[self.input_key] # Other keys are assumed to be needed for LLM prediction other_keys = {k: v for k, v in inputs.items() if k != self.input_key} output, extra_return_dict = self.combine_docs( docs, callbacks=_run_manager.get_child(), **other_keys ) extra_return_dict[self.output_key] = output return extra_return_dict async def _acall( self, inputs: Dict[str, List[Document]], run_manager: Optional[AsyncCallbackManagerForChainRun] = None, ) -> Dict[str, str]:
https://api.python.langchain.com/en/stable/_modules/langchain/chains/combine_documents/base.html
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) -> Dict[str, str]: _run_manager = run_manager or AsyncCallbackManagerForChainRun.get_noop_manager() docs = inputs[self.input_key] # Other keys are assumed to be needed for LLM prediction other_keys = {k: v for k, v in inputs.items() if k != self.input_key} output, extra_return_dict = await self.acombine_docs( docs, callbacks=_run_manager.get_child(), **other_keys ) extra_return_dict[self.output_key] = output return extra_return_dict [docs]class AnalyzeDocumentChain(Chain): """Chain that splits documents, then analyzes it in pieces.""" input_key: str = "input_document" #: :meta private: text_splitter: TextSplitter = Field(default_factory=RecursiveCharacterTextSplitter) combine_docs_chain: BaseCombineDocumentsChain @property def input_keys(self) -> List[str]: """Expect input key. :meta private: """ return [self.input_key] @property def output_keys(self) -> List[str]: """Return output key. :meta private: """ return self.combine_docs_chain.output_keys def _call( self, inputs: Dict[str, str], run_manager: Optional[CallbackManagerForChainRun] = None, ) -> Dict[str, str]: _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager() document = inputs[self.input_key] docs = self.text_splitter.create_documents([document]) # Other keys are assumed to be needed for LLM prediction other_keys: Dict = {k: v for k, v in inputs.items() if k != self.input_key}
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other_keys[self.combine_docs_chain.input_key] = docs return self.combine_docs_chain( other_keys, return_only_outputs=True, callbacks=_run_manager.get_child() )
https://api.python.langchain.com/en/stable/_modules/langchain/chains/combine_documents/base.html
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Source code for langchain.chains.combine_documents.map_reduce """Combining documents by mapping a chain over them first, then combining results.""" from __future__ import annotations from typing import Any, Callable, Dict, List, Optional, Protocol, Tuple from pydantic import Extra, root_validator from langchain.callbacks.manager import Callbacks from langchain.chains.combine_documents.base import BaseCombineDocumentsChain from langchain.chains.llm import LLMChain from langchain.docstore.document import Document class CombineDocsProtocol(Protocol): """Interface for the combine_docs method.""" def __call__(self, docs: List[Document], **kwargs: Any) -> str: """Interface for the combine_docs method.""" def _split_list_of_docs( docs: List[Document], length_func: Callable, token_max: int, **kwargs: Any ) -> List[List[Document]]: new_result_doc_list = [] _sub_result_docs = [] for doc in docs: _sub_result_docs.append(doc) _num_tokens = length_func(_sub_result_docs, **kwargs) if _num_tokens > token_max: if len(_sub_result_docs) == 1: raise ValueError( "A single document was longer than the context length," " we cannot handle this." ) if len(_sub_result_docs) == 2: raise ValueError( "A single document was so long it could not be combined " "with another document, we cannot handle this." ) new_result_doc_list.append(_sub_result_docs[:-1]) _sub_result_docs = _sub_result_docs[-1:] new_result_doc_list.append(_sub_result_docs) return new_result_doc_list def _collapse_docs(
https://api.python.langchain.com/en/stable/_modules/langchain/chains/combine_documents/map_reduce.html
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return new_result_doc_list def _collapse_docs( docs: List[Document], combine_document_func: CombineDocsProtocol, **kwargs: Any, ) -> Document: result = combine_document_func(docs, **kwargs) combined_metadata = {k: str(v) for k, v in docs[0].metadata.items()} for doc in docs[1:]: for k, v in doc.metadata.items(): if k in combined_metadata: combined_metadata[k] += f", {v}" else: combined_metadata[k] = str(v) return Document(page_content=result, metadata=combined_metadata) [docs]class MapReduceDocumentsChain(BaseCombineDocumentsChain): """Combining documents by mapping a chain over them, then combining results.""" llm_chain: LLMChain """Chain to apply to each document individually.""" combine_document_chain: BaseCombineDocumentsChain """Chain to use to combine results of applying llm_chain to documents.""" collapse_document_chain: Optional[BaseCombineDocumentsChain] = None """Chain to use to collapse intermediary results if needed. If None, will use the combine_document_chain.""" document_variable_name: str """The variable name in the llm_chain to put the documents in. If only one variable in the llm_chain, this need not be provided.""" return_intermediate_steps: bool = False """Return the results of the map steps in the output.""" @property def output_keys(self) -> List[str]: """Expect input key. :meta private: """ _output_keys = super().output_keys if self.return_intermediate_steps: _output_keys = _output_keys + ["intermediate_steps"]
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_output_keys = _output_keys + ["intermediate_steps"] return _output_keys class Config: """Configuration for this pydantic object.""" extra = Extra.forbid arbitrary_types_allowed = True @root_validator(pre=True) def get_return_intermediate_steps(cls, values: Dict) -> Dict: """For backwards compatibility.""" if "return_map_steps" in values: values["return_intermediate_steps"] = values["return_map_steps"] del values["return_map_steps"] return values @root_validator(pre=True) def get_default_document_variable_name(cls, values: Dict) -> Dict: """Get default document variable name, if not provided.""" if "document_variable_name" not in values: llm_chain_variables = values["llm_chain"].prompt.input_variables if len(llm_chain_variables) == 1: values["document_variable_name"] = llm_chain_variables[0] else: raise ValueError( "document_variable_name must be provided if there are " "multiple llm_chain input_variables" ) else: llm_chain_variables = values["llm_chain"].prompt.input_variables if values["document_variable_name"] not in llm_chain_variables: raise ValueError( f"document_variable_name {values['document_variable_name']} was " f"not found in llm_chain input_variables: {llm_chain_variables}" ) return values @property def _collapse_chain(self) -> BaseCombineDocumentsChain: if self.collapse_document_chain is not None: return self.collapse_document_chain else: return self.combine_document_chain [docs] def combine_docs( self,
https://api.python.langchain.com/en/stable/_modules/langchain/chains/combine_documents/map_reduce.html
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return self.combine_document_chain [docs] def combine_docs( self, docs: List[Document], token_max: int = 3000, callbacks: Callbacks = None, **kwargs: Any, ) -> Tuple[str, dict]: """Combine documents in a map reduce manner. Combine by mapping first chain over all documents, then reducing the results. This reducing can be done recursively if needed (if there are many documents). """ results = self.llm_chain.apply( # FYI - this is parallelized and so it is fast. [{self.document_variable_name: d.page_content, **kwargs} for d in docs], callbacks=callbacks, ) return self._process_results( results, docs, token_max, callbacks=callbacks, **kwargs ) [docs] async def acombine_docs( self, docs: List[Document], callbacks: Callbacks = None, **kwargs: Any ) -> Tuple[str, dict]: """Combine documents in a map reduce manner. Combine by mapping first chain over all documents, then reducing the results. This reducing can be done recursively if needed (if there are many documents). """ results = await self.llm_chain.aapply( # FYI - this is parallelized and so it is fast. [{**{self.document_variable_name: d.page_content}, **kwargs} for d in docs], callbacks=callbacks, ) return await self._aprocess_results( results, docs, callbacks=callbacks, **kwargs ) def _process_results_common( self, results: List[Dict], docs: List[Document],
https://api.python.langchain.com/en/stable/_modules/langchain/chains/combine_documents/map_reduce.html