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bee5fe1281a2-0 | Source code for langchain.chains.retrieval_qa.base
"""Chain for question-answering against a vector database."""
from __future__ import annotations
import warnings
from abc import abstractmethod
from typing import Any, Dict, List, Optional
from pydantic import Extra, Field, root_validator
from langchain.base_language import BaseLanguageModel
from langchain.callbacks.manager import (
AsyncCallbackManagerForChainRun,
CallbackManagerForChainRun,
)
from langchain.chains.base import Chain
from langchain.chains.combine_documents.base import BaseCombineDocumentsChain
from langchain.chains.combine_documents.stuff import StuffDocumentsChain
from langchain.chains.llm import LLMChain
from langchain.chains.question_answering import load_qa_chain
from langchain.chains.question_answering.stuff_prompt import PROMPT_SELECTOR
from langchain.prompts import PromptTemplate
from langchain.schema import BaseRetriever, Document
from langchain.vectorstores.base import VectorStore
class BaseRetrievalQA(Chain):
combine_documents_chain: BaseCombineDocumentsChain
"""Chain to use to combine the documents."""
input_key: str = "query" #: :meta private:
output_key: str = "result" #: :meta private:
return_source_documents: bool = False
"""Return the source documents."""
class Config:
"""Configuration for this pydantic object."""
extra = Extra.forbid
arbitrary_types_allowed = True
allow_population_by_field_name = True
@property
def input_keys(self) -> List[str]:
"""Return the input keys.
:meta private:
"""
return [self.input_key]
@property
def output_keys(self) -> List[str]:
"""Return the output keys. | https://python.langchain.com/en/latest/_modules/langchain/chains/retrieval_qa/base.html |
bee5fe1281a2-1 | def output_keys(self) -> List[str]:
"""Return the output keys.
:meta private:
"""
_output_keys = [self.output_key]
if self.return_source_documents:
_output_keys = _output_keys + ["source_documents"]
return _output_keys
@classmethod
def from_llm(
cls,
llm: BaseLanguageModel,
prompt: Optional[PromptTemplate] = None,
**kwargs: Any,
) -> BaseRetrievalQA:
"""Initialize from LLM."""
_prompt = prompt or PROMPT_SELECTOR.get_prompt(llm)
llm_chain = LLMChain(llm=llm, prompt=_prompt)
document_prompt = PromptTemplate(
input_variables=["page_content"], template="Context:\n{page_content}"
)
combine_documents_chain = StuffDocumentsChain(
llm_chain=llm_chain,
document_variable_name="context",
document_prompt=document_prompt,
)
return cls(combine_documents_chain=combine_documents_chain, **kwargs)
@classmethod
def from_chain_type(
cls,
llm: BaseLanguageModel,
chain_type: str = "stuff",
chain_type_kwargs: Optional[dict] = None,
**kwargs: Any,
) -> BaseRetrievalQA:
"""Load chain from chain type."""
_chain_type_kwargs = chain_type_kwargs or {}
combine_documents_chain = load_qa_chain(
llm, chain_type=chain_type, **_chain_type_kwargs
)
return cls(combine_documents_chain=combine_documents_chain, **kwargs)
@abstractmethod
def _get_docs(self, question: str) -> List[Document]: | https://python.langchain.com/en/latest/_modules/langchain/chains/retrieval_qa/base.html |
bee5fe1281a2-2 | def _get_docs(self, question: str) -> List[Document]:
"""Get documents to do question answering over."""
def _call(
self,
inputs: Dict[str, Any],
run_manager: Optional[CallbackManagerForChainRun] = None,
) -> Dict[str, Any]:
"""Run get_relevant_text and llm on input query.
If chain has 'return_source_documents' as 'True', returns
the retrieved documents as well under the key 'source_documents'.
Example:
.. code-block:: python
res = indexqa({'query': 'This is my query'})
answer, docs = res['result'], res['source_documents']
"""
_run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager()
question = inputs[self.input_key]
docs = self._get_docs(question)
answer = self.combine_documents_chain.run(
input_documents=docs, question=question, callbacks=_run_manager.get_child()
)
if self.return_source_documents:
return {self.output_key: answer, "source_documents": docs}
else:
return {self.output_key: answer}
@abstractmethod
async def _aget_docs(self, question: str) -> List[Document]:
"""Get documents to do question answering over."""
async def _acall(
self,
inputs: Dict[str, Any],
run_manager: Optional[AsyncCallbackManagerForChainRun] = None,
) -> Dict[str, Any]:
"""Run get_relevant_text and llm on input query.
If chain has 'return_source_documents' as 'True', returns
the retrieved documents as well under the key 'source_documents'.
Example: | https://python.langchain.com/en/latest/_modules/langchain/chains/retrieval_qa/base.html |
bee5fe1281a2-3 | the retrieved documents as well under the key 'source_documents'.
Example:
.. code-block:: python
res = indexqa({'query': 'This is my query'})
answer, docs = res['result'], res['source_documents']
"""
_run_manager = run_manager or AsyncCallbackManagerForChainRun.get_noop_manager()
question = inputs[self.input_key]
docs = await self._aget_docs(question)
answer = await self.combine_documents_chain.arun(
input_documents=docs, question=question, callbacks=_run_manager.get_child()
)
if self.return_source_documents:
return {self.output_key: answer, "source_documents": docs}
else:
return {self.output_key: answer}
[docs]class RetrievalQA(BaseRetrievalQA):
"""Chain for question-answering against an index.
Example:
.. code-block:: python
from langchain.llms import OpenAI
from langchain.chains import RetrievalQA
from langchain.faiss import FAISS
from langchain.vectorstores.base import VectorStoreRetriever
retriever = VectorStoreRetriever(vectorstore=FAISS(...))
retrievalQA = RetrievalQA.from_llm(llm=OpenAI(), retriever=retriever)
"""
retriever: BaseRetriever = Field(exclude=True)
def _get_docs(self, question: str) -> List[Document]:
return self.retriever.get_relevant_documents(question)
async def _aget_docs(self, question: str) -> List[Document]:
return await self.retriever.aget_relevant_documents(question)
[docs]class VectorDBQA(BaseRetrievalQA): | https://python.langchain.com/en/latest/_modules/langchain/chains/retrieval_qa/base.html |
bee5fe1281a2-4 | [docs]class VectorDBQA(BaseRetrievalQA):
"""Chain for question-answering against a vector database."""
vectorstore: VectorStore = Field(exclude=True, alias="vectorstore")
"""Vector Database to connect to."""
k: int = 4
"""Number of documents to query for."""
search_type: str = "similarity"
"""Search type to use over vectorstore. `similarity` or `mmr`."""
search_kwargs: Dict[str, Any] = Field(default_factory=dict)
"""Extra search args."""
@root_validator()
def raise_deprecation(cls, values: Dict) -> Dict:
warnings.warn(
"`VectorDBQA` is deprecated - "
"please use `from langchain.chains import RetrievalQA`"
)
return values
@root_validator()
def validate_search_type(cls, values: Dict) -> Dict:
"""Validate search type."""
if "search_type" in values:
search_type = values["search_type"]
if search_type not in ("similarity", "mmr"):
raise ValueError(f"search_type of {search_type} not allowed.")
return values
def _get_docs(self, question: str) -> List[Document]:
if self.search_type == "similarity":
docs = self.vectorstore.similarity_search(
question, k=self.k, **self.search_kwargs
)
elif self.search_type == "mmr":
docs = self.vectorstore.max_marginal_relevance_search(
question, k=self.k, **self.search_kwargs
)
else:
raise ValueError(f"search_type of {self.search_type} not allowed.")
return docs | https://python.langchain.com/en/latest/_modules/langchain/chains/retrieval_qa/base.html |
bee5fe1281a2-5 | return docs
async def _aget_docs(self, question: str) -> List[Document]:
raise NotImplementedError("VectorDBQA does not support async")
@property
def _chain_type(self) -> str:
"""Return the chain type."""
return "vector_db_qa"
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/chains/retrieval_qa/base.html |
39b0ebe15cc7-0 | Source code for langchain.chains.pal.base
"""Implements Program-Aided Language Models.
As in https://arxiv.org/pdf/2211.10435.pdf.
"""
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.pal.colored_object_prompt import COLORED_OBJECT_PROMPT
from langchain.chains.pal.math_prompt import MATH_PROMPT
from langchain.prompts.base import BasePromptTemplate
from langchain.utilities import PythonREPL
[docs]class PALChain(Chain):
"""Implements Program-Aided Language Models."""
llm_chain: LLMChain
llm: Optional[BaseLanguageModel] = None
"""[Deprecated]"""
prompt: BasePromptTemplate = MATH_PROMPT
"""[Deprecated]"""
stop: str = "\n\n"
get_answer_expr: str = "print(solution())"
python_globals: Optional[Dict[str, Any]] = None
python_locals: Optional[Dict[str, Any]] = None
output_key: str = "result" #: :meta private:
return_intermediate_steps: bool = False
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 PALChain with an llm is deprecated. " | https://python.langchain.com/en/latest/_modules/langchain/chains/pal/base.html |
39b0ebe15cc7-1 | "Directly instantiating an PALChain with an llm is deprecated. "
"Please instantiate with llm_chain argument or using the one of "
"the class method constructors from_math_prompt, "
"from_colored_object_prompt."
)
if "llm_chain" not in values and values["llm"] is not None:
values["llm_chain"] = LLMChain(llm=values["llm"], prompt=MATH_PROMPT)
return values
@property
def input_keys(self) -> List[str]:
"""Return the singular input key.
:meta private:
"""
return self.prompt.input_variables
@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"]
def _call(
self,
inputs: Dict[str, Any],
run_manager: Optional[CallbackManagerForChainRun] = None,
) -> Dict[str, str]:
_run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager()
code = self.llm_chain.predict(
stop=[self.stop], callbacks=_run_manager.get_child(), **inputs
)
_run_manager.on_text(code, color="green", end="\n", verbose=self.verbose)
repl = PythonREPL(_globals=self.python_globals, _locals=self.python_locals)
res = repl.run(code + f"\n{self.get_answer_expr}")
output = {self.output_key: res.strip()}
if self.return_intermediate_steps:
output["intermediate_steps"] = code | https://python.langchain.com/en/latest/_modules/langchain/chains/pal/base.html |
39b0ebe15cc7-2 | if self.return_intermediate_steps:
output["intermediate_steps"] = code
return output
[docs] @classmethod
def from_math_prompt(cls, llm: BaseLanguageModel, **kwargs: Any) -> PALChain:
"""Load PAL from math prompt."""
llm_chain = LLMChain(llm=llm, prompt=MATH_PROMPT)
return cls(
llm_chain=llm_chain,
stop="\n\n",
get_answer_expr="print(solution())",
**kwargs,
)
[docs] @classmethod
def from_colored_object_prompt(
cls, llm: BaseLanguageModel, **kwargs: Any
) -> PALChain:
"""Load PAL from colored object prompt."""
llm_chain = LLMChain(llm=llm, prompt=COLORED_OBJECT_PROMPT)
return cls(
llm_chain=llm_chain,
stop="\n\n\n",
get_answer_expr="print(answer)",
**kwargs,
)
@property
def _chain_type(self) -> str:
return "pal_chain"
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/chains/pal/base.html |
05d16a780e7e-0 | 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 " | https://python.langchain.com/en/latest/_modules/langchain/chains/conversation/base.html |
05d16a780e7e-1 | f"The input key {input_key} was also found in the memory keys "
f"({memory_keys}) - please provide keys that don't overlap."
)
prompt_variables = values["prompt"].input_variables
expected_keys = memory_keys + [input_key]
if set(expected_keys) != set(prompt_variables):
raise ValueError(
"Got unexpected prompt input variables. The prompt expects "
f"{prompt_variables}, but got {memory_keys} as inputs from "
f"memory, and {input_key} as the normal input key."
)
return values
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/chains/conversation/base.html |
2cbd0cc9ee5d-0 | Source code for langchain.retrievers.wikipedia
from typing import List
from langchain.schema import BaseRetriever, Document
from langchain.utilities.wikipedia import WikipediaAPIWrapper
[docs]class WikipediaRetriever(BaseRetriever, WikipediaAPIWrapper):
"""
It is effectively a wrapper for WikipediaAPIWrapper.
It wraps load() to get_relevant_documents().
It uses all WikipediaAPIWrapper arguments without any change.
"""
[docs] def get_relevant_documents(self, query: str) -> List[Document]:
return self.load(query=query)
[docs] async def aget_relevant_documents(self, query: str) -> List[Document]:
raise NotImplementedError
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/wikipedia.html |
0ead0d283996-0 | Source code for langchain.retrievers.pinecone_hybrid_search
"""Taken from: https://docs.pinecone.io/docs/hybrid-search"""
import hashlib
from typing import Any, Dict, List, Optional
from pydantic import BaseModel, Extra, root_validator
from langchain.embeddings.base import Embeddings
from langchain.schema import BaseRetriever, Document
def hash_text(text: str) -> str:
return str(hashlib.sha256(text.encode("utf-8")).hexdigest())
def create_index(
contexts: List[str],
index: Any,
embeddings: Embeddings,
sparse_encoder: Any,
ids: Optional[List[str]] = None,
metadatas: Optional[List[dict]] = None,
) -> None:
batch_size = 32
_iterator = range(0, len(contexts), batch_size)
try:
from tqdm.auto import tqdm
_iterator = tqdm(_iterator)
except ImportError:
pass
if ids is None:
# create unique ids using hash of the text
ids = [hash_text(context) for context in contexts]
for i in _iterator:
# find end of batch
i_end = min(i + batch_size, len(contexts))
# extract batch
context_batch = contexts[i:i_end]
batch_ids = ids[i:i_end]
metadata_batch = (
metadatas[i:i_end] if metadatas else [{} for _ in context_batch]
)
# add context passages as metadata
meta = [
{"context": context, **metadata}
for context, metadata in zip(context_batch, metadata_batch)
]
# create dense vectors
dense_embeds = embeddings.embed_documents(context_batch) | https://python.langchain.com/en/latest/_modules/langchain/retrievers/pinecone_hybrid_search.html |
0ead0d283996-1 | # create dense vectors
dense_embeds = embeddings.embed_documents(context_batch)
# create sparse vectors
sparse_embeds = sparse_encoder.encode_documents(context_batch)
for s in sparse_embeds:
s["values"] = [float(s1) for s1 in s["values"]]
vectors = []
# loop through the data and create dictionaries for upserts
for doc_id, sparse, dense, metadata in zip(
batch_ids, sparse_embeds, dense_embeds, meta
):
vectors.append(
{
"id": doc_id,
"sparse_values": sparse,
"values": dense,
"metadata": metadata,
}
)
# upload the documents to the new hybrid index
index.upsert(vectors)
[docs]class PineconeHybridSearchRetriever(BaseRetriever, BaseModel):
embeddings: Embeddings
sparse_encoder: Any
index: Any
top_k: int = 4
alpha: float = 0.5
class Config:
"""Configuration for this pydantic object."""
extra = Extra.forbid
arbitrary_types_allowed = True
[docs] def add_texts(
self,
texts: List[str],
ids: Optional[List[str]] = None,
metadatas: Optional[List[dict]] = None,
) -> None:
create_index(
texts,
self.index,
self.embeddings,
self.sparse_encoder,
ids=ids,
metadatas=metadatas,
)
@root_validator()
def validate_environment(cls, values: Dict) -> Dict:
"""Validate that api key and python package exists in environment."""
try: | https://python.langchain.com/en/latest/_modules/langchain/retrievers/pinecone_hybrid_search.html |
0ead0d283996-2 | """Validate that api key and python package exists in environment."""
try:
from pinecone_text.hybrid import hybrid_convex_scale # noqa:F401
from pinecone_text.sparse.base_sparse_encoder import (
BaseSparseEncoder, # noqa:F401
)
except ImportError:
raise ValueError(
"Could not import pinecone_text python package. "
"Please install it with `pip install pinecone_text`."
)
return values
[docs] def get_relevant_documents(self, query: str) -> List[Document]:
from pinecone_text.hybrid import hybrid_convex_scale
sparse_vec = self.sparse_encoder.encode_queries(query)
# convert the question into a dense vector
dense_vec = self.embeddings.embed_query(query)
# scale alpha with hybrid_scale
dense_vec, sparse_vec = hybrid_convex_scale(dense_vec, sparse_vec, self.alpha)
sparse_vec["values"] = [float(s1) for s1 in sparse_vec["values"]]
# query pinecone with the query parameters
result = self.index.query(
vector=dense_vec,
sparse_vector=sparse_vec,
top_k=self.top_k,
include_metadata=True,
)
final_result = []
for res in result["matches"]:
context = res["metadata"].pop("context")
final_result.append(
Document(page_content=context, metadata=res["metadata"])
)
# return search results as json
return final_result
[docs] async def aget_relevant_documents(self, query: str) -> List[Document]:
raise NotImplementedError
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/pinecone_hybrid_search.html |
c5ae040622a8-0 | Source code for langchain.retrievers.knn
"""KNN Retriever.
Largely based on
https://github.com/karpathy/randomfun/blob/master/knn_vs_svm.ipynb"""
from __future__ import annotations
import concurrent.futures
from typing import Any, List, Optional
import numpy as np
from pydantic import BaseModel
from langchain.embeddings.base import Embeddings
from langchain.schema import BaseRetriever, Document
def create_index(contexts: List[str], embeddings: Embeddings) -> np.ndarray:
with concurrent.futures.ThreadPoolExecutor() as executor:
return np.array(list(executor.map(embeddings.embed_query, contexts)))
[docs]class KNNRetriever(BaseRetriever, BaseModel):
embeddings: Embeddings
index: Any
texts: List[str]
k: int = 4
relevancy_threshold: Optional[float] = None
class Config:
"""Configuration for this pydantic object."""
arbitrary_types_allowed = True
[docs] @classmethod
def from_texts(
cls, texts: List[str], embeddings: Embeddings, **kwargs: Any
) -> KNNRetriever:
index = create_index(texts, embeddings)
return cls(embeddings=embeddings, index=index, texts=texts, **kwargs)
[docs] def get_relevant_documents(self, query: str) -> List[Document]:
query_embeds = np.array(self.embeddings.embed_query(query))
# calc L2 norm
index_embeds = self.index / np.sqrt((self.index**2).sum(1, keepdims=True))
query_embeds = query_embeds / np.sqrt((query_embeds**2).sum())
similarities = index_embeds.dot(query_embeds) | https://python.langchain.com/en/latest/_modules/langchain/retrievers/knn.html |
c5ae040622a8-1 | similarities = index_embeds.dot(query_embeds)
sorted_ix = np.argsort(-similarities)
denominator = np.max(similarities) - np.min(similarities) + 1e-6
normalized_similarities = (similarities - np.min(similarities)) / denominator
top_k_results = [
Document(page_content=self.texts[row])
for row in sorted_ix[0 : self.k]
if (
self.relevancy_threshold is None
or normalized_similarities[row] >= self.relevancy_threshold
)
]
return top_k_results
[docs] async def aget_relevant_documents(self, query: str) -> List[Document]:
raise NotImplementedError
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/knn.html |
643b4d068e77-0 | Source code for langchain.retrievers.arxiv
from typing import List
from langchain.schema import BaseRetriever, Document
from langchain.utilities.arxiv import ArxivAPIWrapper
[docs]class ArxivRetriever(BaseRetriever, ArxivAPIWrapper):
"""
It is effectively a wrapper for ArxivAPIWrapper.
It wraps load() to get_relevant_documents().
It uses all ArxivAPIWrapper arguments without any change.
"""
[docs] def get_relevant_documents(self, query: str) -> List[Document]:
return self.load(query=query)
[docs] async def aget_relevant_documents(self, query: str) -> List[Document]:
raise NotImplementedError
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/arxiv.html |
47fe7d0cf27a-0 | Source code for langchain.retrievers.databerry
from typing import List, Optional
import aiohttp
import requests
from langchain.schema import BaseRetriever, Document
[docs]class DataberryRetriever(BaseRetriever):
datastore_url: str
top_k: Optional[int]
api_key: Optional[str]
def __init__(
self,
datastore_url: str,
top_k: Optional[int] = None,
api_key: Optional[str] = None,
):
self.datastore_url = datastore_url
self.api_key = api_key
self.top_k = top_k
[docs] def get_relevant_documents(self, query: str) -> List[Document]:
response = requests.post(
self.datastore_url,
json={
"query": query,
**({"topK": self.top_k} if self.top_k is not None else {}),
},
headers={
"Content-Type": "application/json",
**(
{"Authorization": f"Bearer {self.api_key}"}
if self.api_key is not None
else {}
),
},
)
data = response.json()
return [
Document(
page_content=r["text"],
metadata={"source": r["source"], "score": r["score"]},
)
for r in data["results"]
]
[docs] async def aget_relevant_documents(self, query: str) -> List[Document]:
async with aiohttp.ClientSession() as session:
async with session.request(
"POST",
self.datastore_url,
json={
"query": query, | https://python.langchain.com/en/latest/_modules/langchain/retrievers/databerry.html |
47fe7d0cf27a-1 | self.datastore_url,
json={
"query": query,
**({"topK": self.top_k} if self.top_k is not None else {}),
},
headers={
"Content-Type": "application/json",
**(
{"Authorization": f"Bearer {self.api_key}"}
if self.api_key is not None
else {}
),
},
) as response:
data = await response.json()
return [
Document(
page_content=r["text"],
metadata={"source": r["source"], "score": r["score"]},
)
for r in data["results"]
]
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/databerry.html |
7901cb345878-0 | Source code for langchain.retrievers.svm
"""SMV Retriever.
Largely based on
https://github.com/karpathy/randomfun/blob/master/knn_vs_svm.ipynb"""
from __future__ import annotations
import concurrent.futures
from typing import Any, List, Optional
import numpy as np
from pydantic import BaseModel
from langchain.embeddings.base import Embeddings
from langchain.schema import BaseRetriever, Document
def create_index(contexts: List[str], embeddings: Embeddings) -> np.ndarray:
with concurrent.futures.ThreadPoolExecutor() as executor:
return np.array(list(executor.map(embeddings.embed_query, contexts)))
[docs]class SVMRetriever(BaseRetriever, BaseModel):
embeddings: Embeddings
index: Any
texts: List[str]
k: int = 4
relevancy_threshold: Optional[float] = None
class Config:
"""Configuration for this pydantic object."""
arbitrary_types_allowed = True
[docs] @classmethod
def from_texts(
cls, texts: List[str], embeddings: Embeddings, **kwargs: Any
) -> SVMRetriever:
index = create_index(texts, embeddings)
return cls(embeddings=embeddings, index=index, texts=texts, **kwargs)
[docs] def get_relevant_documents(self, query: str) -> List[Document]:
from sklearn import svm
query_embeds = np.array(self.embeddings.embed_query(query))
x = np.concatenate([query_embeds[None, ...], self.index])
y = np.zeros(x.shape[0])
y[0] = 1
clf = svm.LinearSVC( | https://python.langchain.com/en/latest/_modules/langchain/retrievers/svm.html |
7901cb345878-1 | y[0] = 1
clf = svm.LinearSVC(
class_weight="balanced", verbose=False, max_iter=10000, tol=1e-6, C=0.1
)
clf.fit(x, y)
similarities = clf.decision_function(x)
sorted_ix = np.argsort(-similarities)
# svm.LinearSVC in scikit-learn is non-deterministic.
# if a text is the same as a query, there is no guarantee
# the query will be in the first index.
# this performs a simple swap, this works because anything
# left of the 0 should be equivalent.
zero_index = np.where(sorted_ix == 0)[0][0]
if zero_index != 0:
sorted_ix[0], sorted_ix[zero_index] = sorted_ix[zero_index], sorted_ix[0]
denominator = np.max(similarities) - np.min(similarities) + 1e-6
normalized_similarities = (similarities - np.min(similarities)) / denominator
top_k_results = []
for row in sorted_ix[1 : self.k + 1]:
if (
self.relevancy_threshold is None
or normalized_similarities[row] >= self.relevancy_threshold
):
top_k_results.append(Document(page_content=self.texts[row - 1]))
return top_k_results
[docs] async def aget_relevant_documents(self, query: str) -> List[Document]:
raise NotImplementedError
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/svm.html |
5da1350477b8-0 | Source code for langchain.retrievers.contextual_compression
"""Retriever that wraps a base retriever and filters the results."""
from typing import List
from pydantic import BaseModel, Extra
from langchain.retrievers.document_compressors.base import (
BaseDocumentCompressor,
)
from langchain.schema import BaseRetriever, Document
[docs]class ContextualCompressionRetriever(BaseRetriever, BaseModel):
"""Retriever that wraps a base retriever and compresses the results."""
base_compressor: BaseDocumentCompressor
"""Compressor for compressing retrieved documents."""
base_retriever: BaseRetriever
"""Base Retriever to use for getting relevant documents."""
class Config:
"""Configuration for this pydantic object."""
extra = Extra.forbid
arbitrary_types_allowed = True
[docs] def get_relevant_documents(self, query: str) -> List[Document]:
"""Get documents relevant for a query.
Args:
query: string to find relevant documents for
Returns:
Sequence of relevant documents
"""
docs = self.base_retriever.get_relevant_documents(query)
compressed_docs = self.base_compressor.compress_documents(docs, query)
return list(compressed_docs)
[docs] async def aget_relevant_documents(self, query: str) -> List[Document]:
"""Get documents relevant for a query.
Args:
query: string to find relevant documents for
Returns:
List of relevant documents
"""
docs = await self.base_retriever.aget_relevant_documents(query)
compressed_docs = await self.base_compressor.acompress_documents(docs, query)
return list(compressed_docs)
By Harrison Chase | https://python.langchain.com/en/latest/_modules/langchain/retrievers/contextual_compression.html |
5da1350477b8-1 | return list(compressed_docs)
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/contextual_compression.html |
0f2d60d38862-0 | Source code for langchain.retrievers.chatgpt_plugin_retriever
from __future__ import annotations
from typing import List, Optional
import aiohttp
import requests
from pydantic import BaseModel
from langchain.schema import BaseRetriever, Document
[docs]class ChatGPTPluginRetriever(BaseRetriever, BaseModel):
url: str
bearer_token: str
top_k: int = 3
filter: Optional[dict] = None
aiosession: Optional[aiohttp.ClientSession] = None
class Config:
"""Configuration for this pydantic object."""
arbitrary_types_allowed = True
[docs] def get_relevant_documents(self, query: str) -> List[Document]:
url, json, headers = self._create_request(query)
response = requests.post(url, json=json, headers=headers)
results = response.json()["results"][0]["results"]
docs = []
for d in results:
content = d.pop("text")
docs.append(Document(page_content=content, metadata=d))
return docs
[docs] async def aget_relevant_documents(self, query: str) -> List[Document]:
url, json, headers = self._create_request(query)
if not self.aiosession:
async with aiohttp.ClientSession() as session:
async with session.post(url, headers=headers, json=json) as response:
res = await response.json()
else:
async with self.aiosession.post(
url, headers=headers, json=json
) as response:
res = await response.json()
results = res["results"][0]["results"]
docs = []
for d in results:
content = d.pop("text") | https://python.langchain.com/en/latest/_modules/langchain/retrievers/chatgpt_plugin_retriever.html |
0f2d60d38862-1 | for d in results:
content = d.pop("text")
docs.append(Document(page_content=content, metadata=d))
return docs
def _create_request(self, query: str) -> tuple[str, dict, dict]:
url = f"{self.url}/query"
json = {
"queries": [
{
"query": query,
"filter": self.filter,
"top_k": self.top_k,
}
]
}
headers = {
"Content-Type": "application/json",
"Authorization": f"Bearer {self.bearer_token}",
}
return url, json, headers
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/chatgpt_plugin_retriever.html |
a97a5fc7bc72-0 | Source code for langchain.retrievers.tfidf
"""TF-IDF Retriever.
Largely based on
https://github.com/asvskartheek/Text-Retrieval/blob/master/TF-IDF%20Search%20Engine%20(SKLEARN).ipynb"""
from __future__ import annotations
from typing import Any, Dict, Iterable, List, Optional
from pydantic import BaseModel
from langchain.schema import BaseRetriever, Document
[docs]class TFIDFRetriever(BaseRetriever, BaseModel):
vectorizer: Any
docs: List[Document]
tfidf_array: Any
k: int = 4
class Config:
"""Configuration for this pydantic object."""
arbitrary_types_allowed = True
[docs] @classmethod
def from_texts(
cls,
texts: Iterable[str],
metadatas: Optional[Iterable[dict]] = None,
tfidf_params: Optional[Dict[str, Any]] = None,
**kwargs: Any,
) -> TFIDFRetriever:
try:
from sklearn.feature_extraction.text import TfidfVectorizer
except ImportError:
raise ImportError(
"Could not import scikit-learn, please install with `pip install "
"scikit-learn`."
)
tfidf_params = tfidf_params or {}
vectorizer = TfidfVectorizer(**tfidf_params)
tfidf_array = vectorizer.fit_transform(texts)
metadatas = metadatas or ({} for _ in texts)
docs = [Document(page_content=t, metadata=m) for t, m in zip(texts, metadatas)] | https://python.langchain.com/en/latest/_modules/langchain/retrievers/tfidf.html |
a97a5fc7bc72-1 | return cls(vectorizer=vectorizer, docs=docs, tfidf_array=tfidf_array, **kwargs)
[docs] @classmethod
def from_documents(
cls,
documents: Iterable[Document],
*,
tfidf_params: Optional[Dict[str, Any]] = None,
**kwargs: Any,
) -> TFIDFRetriever:
texts, metadatas = zip(*((d.page_content, d.metadata) for d in documents))
return cls.from_texts(
texts=texts, tfidf_params=tfidf_params, metadatas=metadatas, **kwargs
)
[docs] def get_relevant_documents(self, query: str) -> List[Document]:
from sklearn.metrics.pairwise import cosine_similarity
query_vec = self.vectorizer.transform(
[query]
) # Ip -- (n_docs,x), Op -- (n_docs,n_Feats)
results = cosine_similarity(self.tfidf_array, query_vec).reshape(
(-1,)
) # Op -- (n_docs,1) -- Cosine Sim with each doc
return_docs = [self.docs[i] for i in results.argsort()[-self.k :][::-1]]
return return_docs
[docs] async def aget_relevant_documents(self, query: str) -> List[Document]:
raise NotImplementedError
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/tfidf.html |
3947d9bac228-0 | Source code for langchain.retrievers.weaviate_hybrid_search
"""Wrapper around weaviate vector database."""
from __future__ import annotations
from typing import Any, Dict, List, Optional
from uuid import uuid4
from pydantic import Extra
from langchain.docstore.document import Document
from langchain.schema import BaseRetriever
[docs]class WeaviateHybridSearchRetriever(BaseRetriever):
def __init__(
self,
client: Any,
index_name: str,
text_key: str,
alpha: float = 0.5,
k: int = 4,
attributes: Optional[List[str]] = None,
create_schema_if_missing: bool = True,
):
try:
import weaviate
except ImportError:
raise ImportError(
"Could not import weaviate python package. "
"Please install it with `pip install weaviate-client`."
)
if not isinstance(client, weaviate.Client):
raise ValueError(
f"client should be an instance of weaviate.Client, got {type(client)}"
)
self._client = client
self.k = k
self.alpha = alpha
self._index_name = index_name
self._text_key = text_key
self._query_attrs = [self._text_key]
if attributes is not None:
self._query_attrs.extend(attributes)
if create_schema_if_missing:
self._create_schema_if_missing()
def _create_schema_if_missing(self) -> None:
class_obj = {
"class": self._index_name,
"properties": [{"name": self._text_key, "dataType": ["text"]}], | https://python.langchain.com/en/latest/_modules/langchain/retrievers/weaviate_hybrid_search.html |
3947d9bac228-1 | "properties": [{"name": self._text_key, "dataType": ["text"]}],
"vectorizer": "text2vec-openai",
}
if not self._client.schema.exists(self._index_name):
self._client.schema.create_class(class_obj)
[docs] class Config:
"""Configuration for this pydantic object."""
extra = Extra.forbid
arbitrary_types_allowed = True
# added text_key
[docs] def add_documents(self, docs: List[Document], **kwargs: Any) -> List[str]:
"""Upload documents to Weaviate."""
from weaviate.util import get_valid_uuid
with self._client.batch as batch:
ids = []
for i, doc in enumerate(docs):
metadata = doc.metadata or {}
data_properties = {self._text_key: doc.page_content, **metadata}
# If the UUID of one of the objects already exists
# then the existing objectwill be replaced by the new object.
if "uuids" in kwargs:
_id = kwargs["uuids"][i]
else:
_id = get_valid_uuid(uuid4())
batch.add_data_object(data_properties, self._index_name, _id)
ids.append(_id)
return ids
[docs] def get_relevant_documents(
self, query: str, where_filter: Optional[Dict[str, object]] = None
) -> List[Document]:
"""Look up similar documents in Weaviate."""
query_obj = self._client.query.get(self._index_name, self._query_attrs)
if where_filter:
query_obj = query_obj.with_where(where_filter) | https://python.langchain.com/en/latest/_modules/langchain/retrievers/weaviate_hybrid_search.html |
3947d9bac228-2 | if where_filter:
query_obj = query_obj.with_where(where_filter)
result = query_obj.with_hybrid(query, alpha=self.alpha).with_limit(self.k).do()
if "errors" in result:
raise ValueError(f"Error during query: {result['errors']}")
docs = []
for res in result["data"]["Get"][self._index_name]:
text = res.pop(self._text_key)
docs.append(Document(page_content=text, metadata=res))
return docs
[docs] async def aget_relevant_documents(
self, query: str, where_filter: Optional[Dict[str, object]] = None
) -> List[Document]:
raise NotImplementedError
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/weaviate_hybrid_search.html |
739acf7fbb7b-0 | Source code for langchain.retrievers.azure_cognitive_search
"""Retriever wrapper for Azure Cognitive Search."""
from __future__ import annotations
import json
from typing import Dict, List, Optional
import aiohttp
import requests
from pydantic import BaseModel, Extra, root_validator
from langchain.schema import BaseRetriever, Document
from langchain.utils import get_from_dict_or_env
[docs]class AzureCognitiveSearchRetriever(BaseRetriever, BaseModel):
"""Wrapper around Azure Cognitive Search."""
service_name: str = ""
"""Name of Azure Cognitive Search service"""
index_name: str = ""
"""Name of Index inside Azure Cognitive Search service"""
api_key: str = ""
"""API Key. Both Admin and Query keys work, but for reading data it's
recommended to use a Query key."""
api_version: str = "2020-06-30"
"""API version"""
aiosession: Optional[aiohttp.ClientSession] = None
"""ClientSession, in case we want to reuse connection for better performance."""
content_key: str = "content"
"""Key in a retrieved result to set as the Document page_content."""
class Config:
extra = Extra.forbid
arbitrary_types_allowed = True
@root_validator(pre=True)
def validate_environment(cls, values: Dict) -> Dict:
"""Validate that service name, index name and api key exists in environment."""
values["service_name"] = get_from_dict_or_env(
values, "service_name", "AZURE_COGNITIVE_SEARCH_SERVICE_NAME"
)
values["index_name"] = get_from_dict_or_env(
values, "index_name", "AZURE_COGNITIVE_SEARCH_INDEX_NAME"
) | https://python.langchain.com/en/latest/_modules/langchain/retrievers/azure_cognitive_search.html |
739acf7fbb7b-1 | )
values["api_key"] = get_from_dict_or_env(
values, "api_key", "AZURE_COGNITIVE_SEARCH_API_KEY"
)
return values
def _build_search_url(self, query: str) -> str:
base_url = f"https://{self.service_name}.search.windows.net/"
endpoint_path = f"indexes/{self.index_name}/docs?api-version={self.api_version}"
return base_url + endpoint_path + f"&search={query}"
@property
def _headers(self) -> Dict[str, str]:
return {
"Content-Type": "application/json",
"api-key": self.api_key,
}
def _search(self, query: str) -> List[dict]:
search_url = self._build_search_url(query)
response = requests.get(search_url, headers=self._headers)
if response.status_code != 200:
raise Exception(f"Error in search request: {response}")
return json.loads(response.text)["value"]
async def _asearch(self, query: str) -> List[dict]:
search_url = self._build_search_url(query)
if not self.aiosession:
async with aiohttp.ClientSession() as session:
async with session.get(search_url, headers=self._headers) as response:
response_json = await response.json()
else:
async with self.aiosession.get(
search_url, headers=self._headers
) as response:
response_json = await response.json()
return response_json["value"]
[docs] def get_relevant_documents(self, query: str) -> List[Document]:
search_results = self._search(query)
return [ | https://python.langchain.com/en/latest/_modules/langchain/retrievers/azure_cognitive_search.html |
739acf7fbb7b-2 | search_results = self._search(query)
return [
Document(page_content=result.pop(self.content_key), metadata=result)
for result in search_results
]
[docs] async def aget_relevant_documents(self, query: str) -> List[Document]:
search_results = await self._asearch(query)
return [
Document(page_content=result.pop(self.content_key), metadata=result)
for result in search_results
]
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/azure_cognitive_search.html |
525d42f2caab-0 | Source code for langchain.retrievers.remote_retriever
from typing import List, Optional
import aiohttp
import requests
from pydantic import BaseModel
from langchain.schema import BaseRetriever, Document
[docs]class RemoteLangChainRetriever(BaseRetriever, BaseModel):
url: str
headers: Optional[dict] = None
input_key: str = "message"
response_key: str = "response"
page_content_key: str = "page_content"
metadata_key: str = "metadata"
[docs] def get_relevant_documents(self, query: str) -> List[Document]:
response = requests.post(
self.url, json={self.input_key: query}, headers=self.headers
)
result = response.json()
return [
Document(
page_content=r[self.page_content_key], metadata=r[self.metadata_key]
)
for r in result[self.response_key]
]
[docs] async def aget_relevant_documents(self, query: str) -> List[Document]:
async with aiohttp.ClientSession() as session:
async with session.request(
"POST", self.url, headers=self.headers, json={self.input_key: query}
) as response:
result = await response.json()
return [
Document(
page_content=r[self.page_content_key], metadata=r[self.metadata_key]
)
for r in result[self.response_key]
]
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/remote_retriever.html |
2692c0a20b6f-0 | Source code for langchain.retrievers.pupmed
from typing import List
from langchain.schema import BaseRetriever, Document
from langchain.utilities.pupmed import PubMedAPIWrapper
[docs]class PubMedRetriever(BaseRetriever, PubMedAPIWrapper):
"""
It is effectively a wrapper for PubMedAPIWrapper.
It wraps load() to get_relevant_documents().
It uses all PubMedAPIWrapper arguments without any change.
"""
[docs] def get_relevant_documents(self, query: str) -> List[Document]:
return self.load_docs(query=query)
[docs] async def aget_relevant_documents(self, query: str) -> List[Document]:
raise NotImplementedError
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/pupmed.html |
7bffede86950-0 | Source code for langchain.retrievers.metal
from typing import Any, List, Optional
from langchain.schema import BaseRetriever, Document
[docs]class MetalRetriever(BaseRetriever):
def __init__(self, client: Any, params: Optional[dict] = None):
from metal_sdk.metal import Metal
if not isinstance(client, Metal):
raise ValueError(
"Got unexpected client, should be of type metal_sdk.metal.Metal. "
f"Instead, got {type(client)}"
)
self.client: Metal = client
self.params = params or {}
[docs] def get_relevant_documents(self, query: str) -> List[Document]:
results = self.client.search({"text": query}, **self.params)
final_results = []
for r in results["data"]:
metadata = {k: v for k, v in r.items() if k != "text"}
final_results.append(Document(page_content=r["text"], metadata=metadata))
return final_results
[docs] async def aget_relevant_documents(self, query: str) -> List[Document]:
raise NotImplementedError
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/metal.html |
13ce0c825ad7-0 | Source code for langchain.retrievers.vespa_retriever
"""Wrapper for retrieving documents from Vespa."""
from __future__ import annotations
import json
from typing import TYPE_CHECKING, Any, Dict, List, Literal, Optional, Sequence, Union
from langchain.schema import BaseRetriever, Document
if TYPE_CHECKING:
from vespa.application import Vespa
[docs]class VespaRetriever(BaseRetriever):
def __init__(
self,
app: Vespa,
body: Dict,
content_field: str,
metadata_fields: Optional[Sequence[str]] = None,
):
self._application = app
self._query_body = body
self._content_field = content_field
self._metadata_fields = metadata_fields or ()
def _query(self, body: Dict) -> List[Document]:
response = self._application.query(body)
if not str(response.status_code).startswith("2"):
raise RuntimeError(
"Could not retrieve data from Vespa. Error code: {}".format(
response.status_code
)
)
root = response.json["root"]
if "errors" in root:
raise RuntimeError(json.dumps(root["errors"]))
docs = []
for child in response.hits:
page_content = child["fields"].pop(self._content_field, "")
if self._metadata_fields == "*":
metadata = child["fields"]
else:
metadata = {mf: child["fields"].get(mf) for mf in self._metadata_fields}
metadata["id"] = child["id"]
docs.append(Document(page_content=page_content, metadata=metadata))
return docs | https://python.langchain.com/en/latest/_modules/langchain/retrievers/vespa_retriever.html |
13ce0c825ad7-1 | docs.append(Document(page_content=page_content, metadata=metadata))
return docs
[docs] def get_relevant_documents(self, query: str) -> List[Document]:
body = self._query_body.copy()
body["query"] = query
return self._query(body)
[docs] async def aget_relevant_documents(self, query: str) -> List[Document]:
raise NotImplementedError
[docs] def get_relevant_documents_with_filter(
self, query: str, *, _filter: Optional[str] = None
) -> List[Document]:
body = self._query_body.copy()
_filter = f" and {_filter}" if _filter else ""
body["yql"] = body["yql"] + _filter
body["query"] = query
return self._query(body)
[docs] @classmethod
def from_params(
cls,
url: str,
content_field: str,
*,
k: Optional[int] = None,
metadata_fields: Union[Sequence[str], Literal["*"]] = (),
sources: Union[Sequence[str], Literal["*"], None] = None,
_filter: Optional[str] = None,
yql: Optional[str] = None,
**kwargs: Any,
) -> VespaRetriever:
"""Instantiate retriever from params.
Args:
url (str): Vespa app URL.
content_field (str): Field in results to return as Document page_content.
k (Optional[int]): Number of Documents to return. Defaults to None.
metadata_fields(Sequence[str] or "*"): Fields in results to include in
document metadata. Defaults to empty tuple (). | https://python.langchain.com/en/latest/_modules/langchain/retrievers/vespa_retriever.html |
13ce0c825ad7-2 | document metadata. Defaults to empty tuple ().
sources (Sequence[str] or "*" or None): Sources to retrieve
from. Defaults to None.
_filter (Optional[str]): Document filter condition expressed in YQL.
Defaults to None.
yql (Optional[str]): Full YQL query to be used. Should not be specified
if _filter or sources are specified. Defaults to None.
kwargs (Any): Keyword arguments added to query body.
"""
try:
from vespa.application import Vespa
except ImportError:
raise ImportError(
"pyvespa is not installed, please install with `pip install pyvespa`"
)
app = Vespa(url)
body = kwargs.copy()
if yql and (sources or _filter):
raise ValueError(
"yql should only be specified if both sources and _filter are not "
"specified."
)
else:
if metadata_fields == "*":
_fields = "*"
body["summary"] = "short"
else:
_fields = ", ".join([content_field] + list(metadata_fields or []))
_sources = ", ".join(sources) if isinstance(sources, Sequence) else "*"
_filter = f" and {_filter}" if _filter else ""
yql = f"select {_fields} from sources {_sources} where userQuery(){_filter}"
body["yql"] = yql
if k:
body["hits"] = k
return cls(app, body, content_field, metadata_fields=metadata_fields)
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/vespa_retriever.html |
57aba3fdad27-0 | Source code for langchain.retrievers.zep
from __future__ import annotations
from typing import TYPE_CHECKING, Dict, List, Optional
from langchain.schema import BaseRetriever, Document
if TYPE_CHECKING:
from zep_python import MemorySearchResult
[docs]class ZepRetriever(BaseRetriever):
"""A Retriever implementation for the Zep long-term memory store. Search your
user's long-term chat history with Zep.
Note: You will need to provide the user's `session_id` to use this retriever.
More on Zep:
Zep provides long-term conversation storage for LLM apps. The server stores,
summarizes, embeds, indexes, and enriches conversational AI chat
histories, and exposes them via simple, low-latency APIs.
For server installation instructions, see:
https://getzep.github.io/deployment/quickstart/
"""
def __init__(
self,
session_id: str,
url: str,
top_k: Optional[int] = None,
):
try:
from zep_python import ZepClient
except ImportError:
raise ValueError(
"Could not import zep-python package. "
"Please install it with `pip install zep-python`."
)
self.zep_client = ZepClient(base_url=url)
self.session_id = session_id
self.top_k = top_k
def _search_result_to_doc(
self, results: List[MemorySearchResult]
) -> List[Document]:
return [
Document(
page_content=r.message.pop("content"),
metadata={"score": r.dist, **r.message},
)
for r in results | https://python.langchain.com/en/latest/_modules/langchain/retrievers/zep.html |
57aba3fdad27-1 | )
for r in results
if r.message
]
[docs] def get_relevant_documents(
self, query: str, metadata: Optional[Dict] = None
) -> List[Document]:
from zep_python import MemorySearchPayload
payload: MemorySearchPayload = MemorySearchPayload(
text=query, metadata=metadata
)
results: List[MemorySearchResult] = self.zep_client.search_memory(
self.session_id, payload, limit=self.top_k
)
return self._search_result_to_doc(results)
[docs] async def aget_relevant_documents(
self, query: str, metadata: Optional[Dict] = None
) -> List[Document]:
from zep_python import MemorySearchPayload
payload: MemorySearchPayload = MemorySearchPayload(
text=query, metadata=metadata
)
results: List[MemorySearchResult] = await self.zep_client.asearch_memory(
self.session_id, payload, limit=self.top_k
)
return self._search_result_to_doc(results)
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/zep.html |
0d2476affc40-0 | Source code for langchain.retrievers.time_weighted_retriever
"""Retriever that combines embedding similarity with recency in retrieving values."""
import datetime
from copy import deepcopy
from typing import Any, Dict, List, Optional, Tuple
from pydantic import BaseModel, Field
from langchain.schema import BaseRetriever, Document
from langchain.vectorstores.base import VectorStore
def _get_hours_passed(time: datetime.datetime, ref_time: datetime.datetime) -> float:
"""Get the hours passed between two datetime objects."""
return (time - ref_time).total_seconds() / 3600
[docs]class TimeWeightedVectorStoreRetriever(BaseRetriever, BaseModel):
"""Retriever combining embedding similarity with recency."""
vectorstore: VectorStore
"""The vectorstore to store documents and determine salience."""
search_kwargs: dict = Field(default_factory=lambda: dict(k=100))
"""Keyword arguments to pass to the vectorstore similarity search."""
# TODO: abstract as a queue
memory_stream: List[Document] = Field(default_factory=list)
"""The memory_stream of documents to search through."""
decay_rate: float = Field(default=0.01)
"""The exponential decay factor used as (1.0-decay_rate)**(hrs_passed)."""
k: int = 4
"""The maximum number of documents to retrieve in a given call."""
other_score_keys: List[str] = []
"""Other keys in the metadata to factor into the score, e.g. 'importance'."""
default_salience: Optional[float] = None
"""The salience to assign memories not retrieved from the vector store.
None assigns no salience to documents not fetched from the vector store.
"""
class Config: | https://python.langchain.com/en/latest/_modules/langchain/retrievers/time_weighted_retriever.html |
0d2476affc40-1 | """
class Config:
"""Configuration for this pydantic object."""
arbitrary_types_allowed = True
def _get_combined_score(
self,
document: Document,
vector_relevance: Optional[float],
current_time: datetime.datetime,
) -> float:
"""Return the combined score for a document."""
hours_passed = _get_hours_passed(
current_time,
document.metadata["last_accessed_at"],
)
score = (1.0 - self.decay_rate) ** hours_passed
for key in self.other_score_keys:
if key in document.metadata:
score += document.metadata[key]
if vector_relevance is not None:
score += vector_relevance
return score
[docs] def get_salient_docs(self, query: str) -> Dict[int, Tuple[Document, float]]:
"""Return documents that are salient to the query."""
docs_and_scores: List[Tuple[Document, float]]
docs_and_scores = self.vectorstore.similarity_search_with_relevance_scores(
query, **self.search_kwargs
)
results = {}
for fetched_doc, relevance in docs_and_scores:
if "buffer_idx" in fetched_doc.metadata:
buffer_idx = fetched_doc.metadata["buffer_idx"]
doc = self.memory_stream[buffer_idx]
results[buffer_idx] = (doc, relevance)
return results
[docs] def get_relevant_documents(self, query: str) -> List[Document]:
"""Return documents that are relevant to the query."""
current_time = datetime.datetime.now()
docs_and_scores = {
doc.metadata["buffer_idx"]: (doc, self.default_salience)
for doc in self.memory_stream[-self.k :] | https://python.langchain.com/en/latest/_modules/langchain/retrievers/time_weighted_retriever.html |
0d2476affc40-2 | for doc in self.memory_stream[-self.k :]
}
# If a doc is considered salient, update the salience score
docs_and_scores.update(self.get_salient_docs(query))
rescored_docs = [
(doc, self._get_combined_score(doc, relevance, current_time))
for doc, relevance in docs_and_scores.values()
]
rescored_docs.sort(key=lambda x: x[1], reverse=True)
result = []
# Ensure frequently accessed memories aren't forgotten
for doc, _ in rescored_docs[: self.k]:
# TODO: Update vector store doc once `update` method is exposed.
buffered_doc = self.memory_stream[doc.metadata["buffer_idx"]]
buffered_doc.metadata["last_accessed_at"] = current_time
result.append(buffered_doc)
return result
[docs] async def aget_relevant_documents(self, query: str) -> List[Document]:
"""Return documents that are relevant to the query."""
raise NotImplementedError
[docs] def add_documents(self, documents: List[Document], **kwargs: Any) -> List[str]:
"""Add documents to vectorstore."""
current_time = kwargs.get("current_time")
if current_time is None:
current_time = datetime.datetime.now()
# Avoid mutating input documents
dup_docs = [deepcopy(d) for d in documents]
for i, doc in enumerate(dup_docs):
if "last_accessed_at" not in doc.metadata:
doc.metadata["last_accessed_at"] = current_time
if "created_at" not in doc.metadata:
doc.metadata["created_at"] = current_time
doc.metadata["buffer_idx"] = len(self.memory_stream) + i | https://python.langchain.com/en/latest/_modules/langchain/retrievers/time_weighted_retriever.html |
0d2476affc40-3 | doc.metadata["buffer_idx"] = len(self.memory_stream) + i
self.memory_stream.extend(dup_docs)
return self.vectorstore.add_documents(dup_docs, **kwargs)
[docs] async def aadd_documents(
self, documents: List[Document], **kwargs: Any
) -> List[str]:
"""Add documents to vectorstore."""
current_time = kwargs.get("current_time")
if current_time is None:
current_time = datetime.datetime.now()
# Avoid mutating input documents
dup_docs = [deepcopy(d) for d in documents]
for i, doc in enumerate(dup_docs):
if "last_accessed_at" not in doc.metadata:
doc.metadata["last_accessed_at"] = current_time
if "created_at" not in doc.metadata:
doc.metadata["created_at"] = current_time
doc.metadata["buffer_idx"] = len(self.memory_stream) + i
self.memory_stream.extend(dup_docs)
return await self.vectorstore.aadd_documents(dup_docs, **kwargs)
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/time_weighted_retriever.html |
a9e8edd150b9-0 | Source code for langchain.retrievers.elastic_search_bm25
"""Wrapper around Elasticsearch vector database."""
from __future__ import annotations
import uuid
from typing import Any, Iterable, List
from langchain.docstore.document import Document
from langchain.schema import BaseRetriever
[docs]class ElasticSearchBM25Retriever(BaseRetriever):
"""Wrapper around Elasticsearch using BM25 as a retrieval method.
To connect to an Elasticsearch instance that requires login credentials,
including Elastic Cloud, use the Elasticsearch URL format
https://username:password@es_host:9243. For example, to connect to Elastic
Cloud, create the Elasticsearch URL with the required authentication details and
pass it to the ElasticVectorSearch constructor as the named parameter
elasticsearch_url.
You can obtain your Elastic Cloud URL and login credentials by logging in to the
Elastic Cloud console at https://cloud.elastic.co, selecting your deployment, and
navigating to the "Deployments" page.
To obtain your Elastic Cloud password for the default "elastic" user:
1. Log in to the Elastic Cloud console at https://cloud.elastic.co
2. Go to "Security" > "Users"
3. Locate the "elastic" user and click "Edit"
4. Click "Reset password"
5. Follow the prompts to reset the password
The format for Elastic Cloud URLs is
https://username:password@cluster_id.region_id.gcp.cloud.es.io:9243.
"""
def __init__(self, client: Any, index_name: str):
self.client = client
self.index_name = index_name
[docs] @classmethod
def create( | https://python.langchain.com/en/latest/_modules/langchain/retrievers/elastic_search_bm25.html |
a9e8edd150b9-1 | self.index_name = index_name
[docs] @classmethod
def create(
cls, elasticsearch_url: str, index_name: str, k1: float = 2.0, b: float = 0.75
) -> ElasticSearchBM25Retriever:
from elasticsearch import Elasticsearch
# Create an Elasticsearch client instance
es = Elasticsearch(elasticsearch_url)
# Define the index settings and mappings
settings = {
"analysis": {"analyzer": {"default": {"type": "standard"}}},
"similarity": {
"custom_bm25": {
"type": "BM25",
"k1": k1,
"b": b,
}
},
}
mappings = {
"properties": {
"content": {
"type": "text",
"similarity": "custom_bm25", # Use the custom BM25 similarity
}
}
}
# Create the index with the specified settings and mappings
es.indices.create(index=index_name, mappings=mappings, settings=settings)
return cls(es, index_name)
[docs] def add_texts(
self,
texts: Iterable[str],
refresh_indices: bool = True,
) -> List[str]:
"""Run more texts through the embeddings and add to the retriver.
Args:
texts: Iterable of strings to add to the retriever.
refresh_indices: bool to refresh ElasticSearch indices
Returns:
List of ids from adding the texts into the retriever.
"""
try:
from elasticsearch.helpers import bulk
except ImportError:
raise ValueError(
"Could not import elasticsearch python package. " | https://python.langchain.com/en/latest/_modules/langchain/retrievers/elastic_search_bm25.html |
a9e8edd150b9-2 | raise ValueError(
"Could not import elasticsearch python package. "
"Please install it with `pip install elasticsearch`."
)
requests = []
ids = []
for i, text in enumerate(texts):
_id = str(uuid.uuid4())
request = {
"_op_type": "index",
"_index": self.index_name,
"content": text,
"_id": _id,
}
ids.append(_id)
requests.append(request)
bulk(self.client, requests)
if refresh_indices:
self.client.indices.refresh(index=self.index_name)
return ids
[docs] def get_relevant_documents(self, query: str) -> List[Document]:
query_dict = {"query": {"match": {"content": query}}}
res = self.client.search(index=self.index_name, body=query_dict)
docs = []
for r in res["hits"]["hits"]:
docs.append(Document(page_content=r["_source"]["content"]))
return docs
[docs] async def aget_relevant_documents(self, query: str) -> List[Document]:
raise NotImplementedError
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/elastic_search_bm25.html |
10c6282fdd51-0 | Source code for langchain.retrievers.self_query.base
"""Retriever that generates and executes structured queries over its own data source."""
from typing import Any, Dict, List, Optional, Type, cast
from pydantic import BaseModel, Field, root_validator
from langchain import LLMChain
from langchain.base_language import BaseLanguageModel
from langchain.chains.query_constructor.base import load_query_constructor_chain
from langchain.chains.query_constructor.ir import StructuredQuery, Visitor
from langchain.chains.query_constructor.schema import AttributeInfo
from langchain.retrievers.self_query.chroma import ChromaTranslator
from langchain.retrievers.self_query.pinecone import PineconeTranslator
from langchain.retrievers.self_query.qdrant import QdrantTranslator
from langchain.retrievers.self_query.weaviate import WeaviateTranslator
from langchain.schema import BaseRetriever, Document
from langchain.vectorstores import Chroma, Pinecone, Qdrant, VectorStore, Weaviate
def _get_builtin_translator(vectorstore: VectorStore) -> Visitor:
"""Get the translator class corresponding to the vector store class."""
vectorstore_cls = vectorstore.__class__
BUILTIN_TRANSLATORS: Dict[Type[VectorStore], Type[Visitor]] = {
Pinecone: PineconeTranslator,
Chroma: ChromaTranslator,
Weaviate: WeaviateTranslator,
Qdrant: QdrantTranslator,
}
if vectorstore_cls not in BUILTIN_TRANSLATORS:
raise ValueError(
f"Self query retriever with Vector Store type {vectorstore_cls}"
f" not supported."
)
if isinstance(vectorstore, Qdrant):
return QdrantTranslator(metadata_key=vectorstore.metadata_payload_key) | https://python.langchain.com/en/latest/_modules/langchain/retrievers/self_query/base.html |
10c6282fdd51-1 | return QdrantTranslator(metadata_key=vectorstore.metadata_payload_key)
return BUILTIN_TRANSLATORS[vectorstore_cls]()
[docs]class SelfQueryRetriever(BaseRetriever, BaseModel):
"""Retriever that wraps around a vector store and uses an LLM to generate
the vector store queries."""
vectorstore: VectorStore
"""The underlying vector store from which documents will be retrieved."""
llm_chain: LLMChain
"""The LLMChain for generating the vector store queries."""
search_type: str = "similarity"
"""The search type to perform on the vector store."""
search_kwargs: dict = Field(default_factory=dict)
"""Keyword arguments to pass in to the vector store search."""
structured_query_translator: Visitor
"""Translator for turning internal query language into vectorstore search params."""
verbose: bool = False
class Config:
"""Configuration for this pydantic object."""
arbitrary_types_allowed = True
@root_validator(pre=True)
def validate_translator(cls, values: Dict) -> Dict:
"""Validate translator."""
if "structured_query_translator" not in values:
values["structured_query_translator"] = _get_builtin_translator(
values["vectorstore"]
)
return values
[docs] def get_relevant_documents(self, query: str) -> List[Document]:
"""Get documents relevant for a query.
Args:
query: string to find relevant documents for
Returns:
List of relevant documents
"""
inputs = self.llm_chain.prep_inputs({"query": query})
structured_query = cast(
StructuredQuery, self.llm_chain.predict_and_parse(callbacks=None, **inputs)
)
if self.verbose: | https://python.langchain.com/en/latest/_modules/langchain/retrievers/self_query/base.html |
10c6282fdd51-2 | )
if self.verbose:
print(structured_query)
new_query, new_kwargs = self.structured_query_translator.visit_structured_query(
structured_query
)
if structured_query.limit is not None:
new_kwargs["k"] = structured_query.limit
search_kwargs = {**self.search_kwargs, **new_kwargs}
docs = self.vectorstore.search(new_query, self.search_type, **search_kwargs)
return docs
[docs] async def aget_relevant_documents(self, query: str) -> List[Document]:
raise NotImplementedError
[docs] @classmethod
def from_llm(
cls,
llm: BaseLanguageModel,
vectorstore: VectorStore,
document_contents: str,
metadata_field_info: List[AttributeInfo],
structured_query_translator: Optional[Visitor] = None,
chain_kwargs: Optional[Dict] = None,
enable_limit: bool = False,
**kwargs: Any,
) -> "SelfQueryRetriever":
if structured_query_translator is None:
structured_query_translator = _get_builtin_translator(vectorstore)
chain_kwargs = chain_kwargs or {}
if "allowed_comparators" not in chain_kwargs:
chain_kwargs[
"allowed_comparators"
] = structured_query_translator.allowed_comparators
if "allowed_operators" not in chain_kwargs:
chain_kwargs[
"allowed_operators"
] = structured_query_translator.allowed_operators
llm_chain = load_query_constructor_chain(
llm,
document_contents,
metadata_field_info,
enable_limit=enable_limit,
**chain_kwargs,
)
return cls( | https://python.langchain.com/en/latest/_modules/langchain/retrievers/self_query/base.html |
10c6282fdd51-3 | **chain_kwargs,
)
return cls(
llm_chain=llm_chain,
vectorstore=vectorstore,
structured_query_translator=structured_query_translator,
**kwargs,
)
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/self_query/base.html |
696baaf34630-0 | Source code for langchain.retrievers.document_compressors.cohere_rerank
from __future__ import annotations
from typing import TYPE_CHECKING, Dict, Sequence
from pydantic import Extra, root_validator
from langchain.retrievers.document_compressors.base import BaseDocumentCompressor
from langchain.schema import Document
from langchain.utils import get_from_dict_or_env
if TYPE_CHECKING:
from cohere import Client
else:
# We do to avoid pydantic annotation issues when actually instantiating
# while keeping this import optional
try:
from cohere import Client
except ImportError:
pass
[docs]class CohereRerank(BaseDocumentCompressor):
client: Client
top_n: int = 3
model: str = "rerank-english-v2.0"
class Config:
"""Configuration for this pydantic object."""
extra = Extra.forbid
arbitrary_types_allowed = True
@root_validator(pre=True)
def validate_environment(cls, values: Dict) -> Dict:
"""Validate that api key and python package exists in environment."""
cohere_api_key = get_from_dict_or_env(
values, "cohere_api_key", "COHERE_API_KEY"
)
try:
import cohere
values["client"] = cohere.Client(cohere_api_key)
except ImportError:
raise ImportError(
"Could not import cohere python package. "
"Please install it with `pip install cohere`."
)
return values
[docs] def compress_documents(
self, documents: Sequence[Document], query: str
) -> Sequence[Document]:
if len(documents) == 0: # to avoid empty api call
return [] | https://python.langchain.com/en/latest/_modules/langchain/retrievers/document_compressors/cohere_rerank.html |
696baaf34630-1 | return []
doc_list = list(documents)
_docs = [d.page_content for d in doc_list]
results = self.client.rerank(
model=self.model, query=query, documents=_docs, top_n=self.top_n
)
final_results = []
for r in results:
doc = doc_list[r.index]
doc.metadata["relevance_score"] = r.relevance_score
final_results.append(doc)
return final_results
[docs] async def acompress_documents(
self, documents: Sequence[Document], query: str
) -> Sequence[Document]:
raise NotImplementedError
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/document_compressors/cohere_rerank.html |
3888adb2c5a6-0 | Source code for langchain.retrievers.document_compressors.base
"""Interface for retrieved document compressors."""
from abc import ABC, abstractmethod
from typing import List, Sequence, Union
from pydantic import BaseModel
from langchain.schema import BaseDocumentTransformer, Document
class BaseDocumentCompressor(BaseModel, ABC):
"""Base abstraction interface for document compression."""
@abstractmethod
def compress_documents(
self, documents: Sequence[Document], query: str
) -> Sequence[Document]:
"""Compress retrieved documents given the query context."""
@abstractmethod
async def acompress_documents(
self, documents: Sequence[Document], query: str
) -> Sequence[Document]:
"""Compress retrieved documents given the query context."""
[docs]class DocumentCompressorPipeline(BaseDocumentCompressor):
"""Document compressor that uses a pipeline of transformers."""
transformers: List[Union[BaseDocumentTransformer, BaseDocumentCompressor]]
"""List of document filters that are chained together and run in sequence."""
class Config:
"""Configuration for this pydantic object."""
arbitrary_types_allowed = True
[docs] def compress_documents(
self, documents: Sequence[Document], query: str
) -> Sequence[Document]:
"""Transform a list of documents."""
for _transformer in self.transformers:
if isinstance(_transformer, BaseDocumentCompressor):
documents = _transformer.compress_documents(documents, query)
elif isinstance(_transformer, BaseDocumentTransformer):
documents = _transformer.transform_documents(documents)
else:
raise ValueError(f"Got unexpected transformer type: {_transformer}")
return documents
[docs] async def acompress_documents(
self, documents: Sequence[Document], query: str | https://python.langchain.com/en/latest/_modules/langchain/retrievers/document_compressors/base.html |
3888adb2c5a6-1 | self, documents: Sequence[Document], query: str
) -> Sequence[Document]:
"""Compress retrieved documents given the query context."""
for _transformer in self.transformers:
if isinstance(_transformer, BaseDocumentCompressor):
documents = await _transformer.acompress_documents(documents, query)
elif isinstance(_transformer, BaseDocumentTransformer):
documents = await _transformer.atransform_documents(documents)
else:
raise ValueError(f"Got unexpected transformer type: {_transformer}")
return documents
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/document_compressors/base.html |
af4bdd4dd0b9-0 | Source code for langchain.retrievers.document_compressors.chain_extract
"""DocumentFilter that uses an LLM chain to extract the relevant parts of documents."""
from __future__ import annotations
import asyncio
from typing import Any, Callable, Dict, Optional, Sequence
from langchain import LLMChain, PromptTemplate
from langchain.base_language import BaseLanguageModel
from langchain.retrievers.document_compressors.base import BaseDocumentCompressor
from langchain.retrievers.document_compressors.chain_extract_prompt import (
prompt_template,
)
from langchain.schema import BaseOutputParser, Document
def default_get_input(query: str, doc: Document) -> Dict[str, Any]:
"""Return the compression chain input."""
return {"question": query, "context": doc.page_content}
class NoOutputParser(BaseOutputParser[str]):
"""Parse outputs that could return a null string of some sort."""
no_output_str: str = "NO_OUTPUT"
def parse(self, text: str) -> str:
cleaned_text = text.strip()
if cleaned_text == self.no_output_str:
return ""
return cleaned_text
def _get_default_chain_prompt() -> PromptTemplate:
output_parser = NoOutputParser()
template = prompt_template.format(no_output_str=output_parser.no_output_str)
return PromptTemplate(
template=template,
input_variables=["question", "context"],
output_parser=output_parser,
)
[docs]class LLMChainExtractor(BaseDocumentCompressor):
llm_chain: LLMChain
"""LLM wrapper to use for compressing documents."""
get_input: Callable[[str, Document], dict] = default_get_input
"""Callable for constructing the chain input from the query and a Document."""
[docs] def compress_documents( | https://python.langchain.com/en/latest/_modules/langchain/retrievers/document_compressors/chain_extract.html |
af4bdd4dd0b9-1 | [docs] def compress_documents(
self, documents: Sequence[Document], query: str
) -> Sequence[Document]:
"""Compress page content of raw documents."""
compressed_docs = []
for doc in documents:
_input = self.get_input(query, doc)
output = self.llm_chain.predict_and_parse(**_input)
if len(output) == 0:
continue
compressed_docs.append(Document(page_content=output, metadata=doc.metadata))
return compressed_docs
[docs] async def acompress_documents(
self, documents: Sequence[Document], query: str
) -> Sequence[Document]:
"""Compress page content of raw documents asynchronously."""
outputs = await asyncio.gather(
*[
self.llm_chain.apredict_and_parse(**self.get_input(query, doc))
for doc in documents
]
)
compressed_docs = []
for i, doc in enumerate(documents):
if len(outputs[i]) == 0:
continue
compressed_docs.append(
Document(page_content=outputs[i], metadata=doc.metadata)
)
return compressed_docs
[docs] @classmethod
def from_llm(
cls,
llm: BaseLanguageModel,
prompt: Optional[PromptTemplate] = None,
get_input: Optional[Callable[[str, Document], str]] = None,
llm_chain_kwargs: Optional[dict] = None,
) -> LLMChainExtractor:
"""Initialize from LLM."""
_prompt = prompt if prompt is not None else _get_default_chain_prompt()
_get_input = get_input if get_input is not None else default_get_input | https://python.langchain.com/en/latest/_modules/langchain/retrievers/document_compressors/chain_extract.html |
af4bdd4dd0b9-2 | _get_input = get_input if get_input is not None else default_get_input
llm_chain = LLMChain(llm=llm, prompt=_prompt, **(llm_chain_kwargs or {}))
return cls(llm_chain=llm_chain, get_input=_get_input)
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/document_compressors/chain_extract.html |
01b0ebad7c19-0 | Source code for langchain.retrievers.document_compressors.embeddings_filter
"""Document compressor that uses embeddings to drop documents unrelated to the query."""
from typing import Callable, Dict, Optional, Sequence
import numpy as np
from pydantic import root_validator
from langchain.document_transformers import (
_get_embeddings_from_stateful_docs,
get_stateful_documents,
)
from langchain.embeddings.base import Embeddings
from langchain.math_utils import cosine_similarity
from langchain.retrievers.document_compressors.base import (
BaseDocumentCompressor,
)
from langchain.schema import Document
[docs]class EmbeddingsFilter(BaseDocumentCompressor):
embeddings: Embeddings
"""Embeddings to use for embedding document contents and queries."""
similarity_fn: Callable = cosine_similarity
"""Similarity function for comparing documents. Function expected to take as input
two matrices (List[List[float]]) and return a matrix of scores where higher values
indicate greater similarity."""
k: Optional[int] = 20
"""The number of relevant documents to return. Can be set to None, in which case
`similarity_threshold` must be specified. Defaults to 20."""
similarity_threshold: Optional[float]
"""Threshold for determining when two documents are similar enough
to be considered redundant. Defaults to None, must be specified if `k` is set
to None."""
class Config:
"""Configuration for this pydantic object."""
arbitrary_types_allowed = True
@root_validator()
def validate_params(cls, values: Dict) -> Dict:
"""Validate similarity parameters."""
if values["k"] is None and values["similarity_threshold"] is None:
raise ValueError("Must specify one of `k` or `similarity_threshold`.")
return values | https://python.langchain.com/en/latest/_modules/langchain/retrievers/document_compressors/embeddings_filter.html |
01b0ebad7c19-1 | return values
[docs] def compress_documents(
self, documents: Sequence[Document], query: str
) -> Sequence[Document]:
"""Filter documents based on similarity of their embeddings to the query."""
stateful_documents = get_stateful_documents(documents)
embedded_documents = _get_embeddings_from_stateful_docs(
self.embeddings, stateful_documents
)
embedded_query = self.embeddings.embed_query(query)
similarity = self.similarity_fn([embedded_query], embedded_documents)[0]
included_idxs = np.arange(len(embedded_documents))
if self.k is not None:
included_idxs = np.argsort(similarity)[::-1][: self.k]
if self.similarity_threshold is not None:
similar_enough = np.where(
similarity[included_idxs] > self.similarity_threshold
)
included_idxs = included_idxs[similar_enough]
return [stateful_documents[i] for i in included_idxs]
[docs] async def acompress_documents(
self, documents: Sequence[Document], query: str
) -> Sequence[Document]:
"""Filter down documents."""
raise NotImplementedError
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/document_compressors/embeddings_filter.html |
e7ba3c7cb21f-0 | Source code for langchain.retrievers.document_compressors.chain_filter
"""Filter that uses an LLM to drop documents that aren't relevant to the query."""
from typing import Any, Callable, Dict, Optional, Sequence
from langchain import BasePromptTemplate, LLMChain, PromptTemplate
from langchain.base_language import BaseLanguageModel
from langchain.output_parsers.boolean import BooleanOutputParser
from langchain.retrievers.document_compressors.base import BaseDocumentCompressor
from langchain.retrievers.document_compressors.chain_filter_prompt import (
prompt_template,
)
from langchain.schema import Document
def _get_default_chain_prompt() -> PromptTemplate:
return PromptTemplate(
template=prompt_template,
input_variables=["question", "context"],
output_parser=BooleanOutputParser(),
)
def default_get_input(query: str, doc: Document) -> Dict[str, Any]:
"""Return the compression chain input."""
return {"question": query, "context": doc.page_content}
[docs]class LLMChainFilter(BaseDocumentCompressor):
"""Filter that drops documents that aren't relevant to the query."""
llm_chain: LLMChain
"""LLM wrapper to use for filtering documents.
The chain prompt is expected to have a BooleanOutputParser."""
get_input: Callable[[str, Document], dict] = default_get_input
"""Callable for constructing the chain input from the query and a Document."""
[docs] def compress_documents(
self, documents: Sequence[Document], query: str
) -> Sequence[Document]:
"""Filter down documents based on their relevance to the query."""
filtered_docs = []
for doc in documents:
_input = self.get_input(query, doc)
include_doc = self.llm_chain.predict_and_parse(**_input) | https://python.langchain.com/en/latest/_modules/langchain/retrievers/document_compressors/chain_filter.html |
e7ba3c7cb21f-1 | include_doc = self.llm_chain.predict_and_parse(**_input)
if include_doc:
filtered_docs.append(doc)
return filtered_docs
[docs] async def acompress_documents(
self, documents: Sequence[Document], query: str
) -> Sequence[Document]:
"""Filter down documents."""
raise NotImplementedError
[docs] @classmethod
def from_llm(
cls,
llm: BaseLanguageModel,
prompt: Optional[BasePromptTemplate] = None,
**kwargs: Any
) -> "LLMChainFilter":
_prompt = prompt if prompt is not None else _get_default_chain_prompt()
llm_chain = LLMChain(llm=llm, prompt=_prompt)
return cls(llm_chain=llm_chain, **kwargs)
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/retrievers/document_compressors/chain_filter.html |
e117e2c0e128-0 | Source code for langchain.memory.vectorstore
"""Class for a VectorStore-backed memory object."""
from typing import Any, Dict, List, Optional, Union
from pydantic import Field
from langchain.memory.chat_memory import BaseMemory
from langchain.memory.utils import get_prompt_input_key
from langchain.schema import Document
from langchain.vectorstores.base import VectorStoreRetriever
[docs]class VectorStoreRetrieverMemory(BaseMemory):
"""Class for a VectorStore-backed memory object."""
retriever: VectorStoreRetriever = Field(exclude=True)
"""VectorStoreRetriever object to connect to."""
memory_key: str = "history" #: :meta private:
"""Key name to locate the memories in the result of load_memory_variables."""
input_key: Optional[str] = None
"""Key name to index the inputs to load_memory_variables."""
return_docs: bool = False
"""Whether or not to return the result of querying the database directly."""
@property
def memory_variables(self) -> List[str]:
"""The list of keys emitted from the load_memory_variables method."""
return [self.memory_key]
def _get_prompt_input_key(self, inputs: Dict[str, Any]) -> str:
"""Get the input key for the prompt."""
if self.input_key is None:
return get_prompt_input_key(inputs, self.memory_variables)
return self.input_key
[docs] def load_memory_variables(
self, inputs: Dict[str, Any]
) -> Dict[str, Union[List[Document], str]]:
"""Return history buffer."""
input_key = self._get_prompt_input_key(inputs)
query = inputs[input_key]
docs = self.retriever.get_relevant_documents(query) | https://python.langchain.com/en/latest/_modules/langchain/memory/vectorstore.html |
e117e2c0e128-1 | docs = self.retriever.get_relevant_documents(query)
result: Union[List[Document], str]
if not self.return_docs:
result = "\n".join([doc.page_content for doc in docs])
else:
result = docs
return {self.memory_key: result}
def _form_documents(
self, inputs: Dict[str, Any], outputs: Dict[str, str]
) -> List[Document]:
"""Format context from this conversation to buffer."""
# Each document should only include the current turn, not the chat history
filtered_inputs = {k: v for k, v in inputs.items() if k != self.memory_key}
texts = [
f"{k}: {v}"
for k, v in list(filtered_inputs.items()) + list(outputs.items())
]
page_content = "\n".join(texts)
return [Document(page_content=page_content)]
[docs] def save_context(self, inputs: Dict[str, Any], outputs: Dict[str, str]) -> None:
"""Save context from this conversation to buffer."""
documents = self._form_documents(inputs, outputs)
self.retriever.add_documents(documents)
[docs] def clear(self) -> None:
"""Nothing to clear."""
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/memory/vectorstore.html |
4570d2508ec6-0 | Source code for langchain.memory.token_buffer
from typing import Any, Dict, List
from langchain.base_language import BaseLanguageModel
from langchain.memory.chat_memory import BaseChatMemory
from langchain.schema import BaseMessage, get_buffer_string
[docs]class ConversationTokenBufferMemory(BaseChatMemory):
"""Buffer for storing conversation memory."""
human_prefix: str = "Human"
ai_prefix: str = "AI"
llm: BaseLanguageModel
memory_key: str = "history"
max_token_limit: int = 2000
@property
def buffer(self) -> List[BaseMessage]:
"""String buffer of memory."""
return self.chat_memory.messages
@property
def memory_variables(self) -> List[str]:
"""Will always return list of memory variables.
:meta private:
"""
return [self.memory_key]
[docs] def load_memory_variables(self, inputs: Dict[str, Any]) -> Dict[str, Any]:
"""Return history buffer."""
buffer: Any = self.buffer
if self.return_messages:
final_buffer: Any = buffer
else:
final_buffer = get_buffer_string(
buffer,
human_prefix=self.human_prefix,
ai_prefix=self.ai_prefix,
)
return {self.memory_key: final_buffer}
[docs] def save_context(self, inputs: Dict[str, Any], outputs: Dict[str, str]) -> None:
"""Save context from this conversation to buffer. Pruned."""
super().save_context(inputs, outputs)
# Prune buffer if it exceeds max token limit
buffer = self.chat_memory.messages
curr_buffer_length = self.llm.get_num_tokens_from_messages(buffer)
if curr_buffer_length > self.max_token_limit: | https://python.langchain.com/en/latest/_modules/langchain/memory/token_buffer.html |
4570d2508ec6-1 | if curr_buffer_length > self.max_token_limit:
pruned_memory = []
while curr_buffer_length > self.max_token_limit:
pruned_memory.append(buffer.pop(0))
curr_buffer_length = self.llm.get_num_tokens_from_messages(buffer)
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/memory/token_buffer.html |
0d9192231543-0 | Source code for langchain.memory.summary_buffer
from typing import Any, Dict, List
from pydantic import root_validator
from langchain.memory.chat_memory import BaseChatMemory
from langchain.memory.summary import SummarizerMixin
from langchain.schema import BaseMessage, get_buffer_string
[docs]class ConversationSummaryBufferMemory(BaseChatMemory, SummarizerMixin):
"""Buffer with summarizer for storing conversation memory."""
max_token_limit: int = 2000
moving_summary_buffer: str = ""
memory_key: str = "history"
@property
def buffer(self) -> List[BaseMessage]:
return self.chat_memory.messages
@property
def memory_variables(self) -> List[str]:
"""Will always return list of memory variables.
:meta private:
"""
return [self.memory_key]
[docs] def load_memory_variables(self, inputs: Dict[str, Any]) -> Dict[str, Any]:
"""Return history buffer."""
buffer = self.buffer
if self.moving_summary_buffer != "":
first_messages: List[BaseMessage] = [
self.summary_message_cls(content=self.moving_summary_buffer)
]
buffer = first_messages + buffer
if self.return_messages:
final_buffer: Any = buffer
else:
final_buffer = get_buffer_string(
buffer, human_prefix=self.human_prefix, ai_prefix=self.ai_prefix
)
return {self.memory_key: final_buffer}
@root_validator()
def validate_prompt_input_variables(cls, values: Dict) -> Dict:
"""Validate that prompt input variables are consistent."""
prompt_variables = values["prompt"].input_variables
expected_keys = {"summary", "new_lines"}
if expected_keys != set(prompt_variables):
raise ValueError( | https://python.langchain.com/en/latest/_modules/langchain/memory/summary_buffer.html |
0d9192231543-1 | if expected_keys != set(prompt_variables):
raise ValueError(
"Got unexpected prompt input variables. The prompt expects "
f"{prompt_variables}, but it should have {expected_keys}."
)
return values
[docs] def save_context(self, inputs: Dict[str, Any], outputs: Dict[str, str]) -> None:
"""Save context from this conversation to buffer."""
super().save_context(inputs, outputs)
self.prune()
[docs] def prune(self) -> None:
"""Prune buffer if it exceeds max token limit"""
buffer = self.chat_memory.messages
curr_buffer_length = self.llm.get_num_tokens_from_messages(buffer)
if curr_buffer_length > self.max_token_limit:
pruned_memory = []
while curr_buffer_length > self.max_token_limit:
pruned_memory.append(buffer.pop(0))
curr_buffer_length = self.llm.get_num_tokens_from_messages(buffer)
self.moving_summary_buffer = self.predict_new_summary(
pruned_memory, self.moving_summary_buffer
)
[docs] def clear(self) -> None:
"""Clear memory contents."""
super().clear()
self.moving_summary_buffer = ""
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/memory/summary_buffer.html |
9fa6bf712415-0 | Source code for langchain.memory.buffer_window
from typing import Any, Dict, List
from langchain.memory.chat_memory import BaseChatMemory
from langchain.schema import BaseMessage, get_buffer_string
[docs]class ConversationBufferWindowMemory(BaseChatMemory):
"""Buffer for storing conversation memory."""
human_prefix: str = "Human"
ai_prefix: str = "AI"
memory_key: str = "history" #: :meta private:
k: int = 5
@property
def buffer(self) -> List[BaseMessage]:
"""String buffer of memory."""
return self.chat_memory.messages
@property
def memory_variables(self) -> List[str]:
"""Will always return list of memory variables.
:meta private:
"""
return [self.memory_key]
[docs] def load_memory_variables(self, inputs: Dict[str, Any]) -> Dict[str, str]:
"""Return history buffer."""
buffer: Any = self.buffer[-self.k * 2 :] if self.k > 0 else []
if not self.return_messages:
buffer = get_buffer_string(
buffer,
human_prefix=self.human_prefix,
ai_prefix=self.ai_prefix,
)
return {self.memory_key: buffer}
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/memory/buffer_window.html |
e732b166b109-0 | Source code for langchain.memory.combined
import warnings
from typing import Any, Dict, List, Set
from pydantic import validator
from langchain.memory.chat_memory import BaseChatMemory
from langchain.schema import BaseMemory
[docs]class CombinedMemory(BaseMemory):
"""Class for combining multiple memories' data together."""
memories: List[BaseMemory]
"""For tracking all the memories that should be accessed."""
@validator("memories")
def check_repeated_memory_variable(
cls, value: List[BaseMemory]
) -> List[BaseMemory]:
all_variables: Set[str] = set()
for val in value:
overlap = all_variables.intersection(val.memory_variables)
if overlap:
raise ValueError(
f"The same variables {overlap} are found in multiple"
"memory object, which is not allowed by CombinedMemory."
)
all_variables |= set(val.memory_variables)
return value
@validator("memories")
def check_input_key(cls, value: List[BaseMemory]) -> List[BaseMemory]:
"""Check that if memories are of type BaseChatMemory that input keys exist."""
for val in value:
if isinstance(val, BaseChatMemory):
if val.input_key is None:
warnings.warn(
"When using CombinedMemory, "
"input keys should be so the input is known. "
f" Was not set on {val}"
)
return value
@property
def memory_variables(self) -> List[str]:
"""All the memory variables that this instance provides."""
"""Collected from the all the linked memories."""
memory_variables = []
for memory in self.memories:
memory_variables.extend(memory.memory_variables) | https://python.langchain.com/en/latest/_modules/langchain/memory/combined.html |
e732b166b109-1 | for memory in self.memories:
memory_variables.extend(memory.memory_variables)
return memory_variables
[docs] def load_memory_variables(self, inputs: Dict[str, Any]) -> Dict[str, str]:
"""Load all vars from sub-memories."""
memory_data: Dict[str, Any] = {}
# Collect vars from all sub-memories
for memory in self.memories:
data = memory.load_memory_variables(inputs)
memory_data = {
**memory_data,
**data,
}
return memory_data
[docs] def save_context(self, inputs: Dict[str, Any], outputs: Dict[str, str]) -> None:
"""Save context from this session for every memory."""
# Save context for all sub-memories
for memory in self.memories:
memory.save_context(inputs, outputs)
[docs] def clear(self) -> None:
"""Clear context from this session for every memory."""
for memory in self.memories:
memory.clear()
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/memory/combined.html |
663c07ebd9fa-0 | Source code for langchain.memory.simple
from typing import Any, Dict, List
from langchain.schema import BaseMemory
[docs]class SimpleMemory(BaseMemory):
"""Simple memory for storing context or other bits of information that shouldn't
ever change between prompts.
"""
memories: Dict[str, Any] = dict()
@property
def memory_variables(self) -> List[str]:
return list(self.memories.keys())
[docs] def load_memory_variables(self, inputs: Dict[str, Any]) -> Dict[str, str]:
return self.memories
[docs] def save_context(self, inputs: Dict[str, Any], outputs: Dict[str, str]) -> None:
"""Nothing should be saved or changed, my memory is set in stone."""
pass
[docs] def clear(self) -> None:
"""Nothing to clear, got a memory like a vault."""
pass
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/memory/simple.html |
da14d0a0ae48-0 | Source code for langchain.memory.summary
from __future__ import annotations
from typing import Any, Dict, List, Type
from pydantic import BaseModel, root_validator
from langchain.base_language import BaseLanguageModel
from langchain.chains.llm import LLMChain
from langchain.memory.chat_memory import BaseChatMemory
from langchain.memory.prompt import SUMMARY_PROMPT
from langchain.prompts.base import BasePromptTemplate
from langchain.schema import (
BaseChatMessageHistory,
BaseMessage,
SystemMessage,
get_buffer_string,
)
class SummarizerMixin(BaseModel):
human_prefix: str = "Human"
ai_prefix: str = "AI"
llm: BaseLanguageModel
prompt: BasePromptTemplate = SUMMARY_PROMPT
summary_message_cls: Type[BaseMessage] = SystemMessage
def predict_new_summary(
self, messages: List[BaseMessage], existing_summary: str
) -> str:
new_lines = get_buffer_string(
messages,
human_prefix=self.human_prefix,
ai_prefix=self.ai_prefix,
)
chain = LLMChain(llm=self.llm, prompt=self.prompt)
return chain.predict(summary=existing_summary, new_lines=new_lines)
[docs]class ConversationSummaryMemory(BaseChatMemory, SummarizerMixin):
"""Conversation summarizer to memory."""
buffer: str = ""
memory_key: str = "history" #: :meta private:
[docs] @classmethod
def from_messages(
cls,
llm: BaseLanguageModel,
chat_memory: BaseChatMessageHistory,
*,
summarize_step: int = 2,
**kwargs: Any,
) -> ConversationSummaryMemory: | https://python.langchain.com/en/latest/_modules/langchain/memory/summary.html |
da14d0a0ae48-1 | **kwargs: Any,
) -> ConversationSummaryMemory:
obj = cls(llm=llm, chat_memory=chat_memory, **kwargs)
for i in range(0, len(obj.chat_memory.messages), summarize_step):
obj.buffer = obj.predict_new_summary(
obj.chat_memory.messages[i : i + summarize_step], obj.buffer
)
return obj
@property
def memory_variables(self) -> List[str]:
"""Will always return list of memory variables.
:meta private:
"""
return [self.memory_key]
[docs] def load_memory_variables(self, inputs: Dict[str, Any]) -> Dict[str, Any]:
"""Return history buffer."""
if self.return_messages:
buffer: Any = [self.summary_message_cls(content=self.buffer)]
else:
buffer = self.buffer
return {self.memory_key: buffer}
@root_validator()
def validate_prompt_input_variables(cls, values: Dict) -> Dict:
"""Validate that prompt input variables are consistent."""
prompt_variables = values["prompt"].input_variables
expected_keys = {"summary", "new_lines"}
if expected_keys != set(prompt_variables):
raise ValueError(
"Got unexpected prompt input variables. The prompt expects "
f"{prompt_variables}, but it should have {expected_keys}."
)
return values
[docs] def save_context(self, inputs: Dict[str, Any], outputs: Dict[str, str]) -> None:
"""Save context from this conversation to buffer."""
super().save_context(inputs, outputs)
self.buffer = self.predict_new_summary(
self.chat_memory.messages[-2:], self.buffer
)
[docs] def clear(self) -> None:
"""Clear memory contents.""" | https://python.langchain.com/en/latest/_modules/langchain/memory/summary.html |
da14d0a0ae48-2 | [docs] def clear(self) -> None:
"""Clear memory contents."""
super().clear()
self.buffer = ""
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/memory/summary.html |
304bf7f3d154-0 | Source code for langchain.memory.kg
from typing import Any, Dict, List, Type, Union
from pydantic import Field
from langchain.base_language import BaseLanguageModel
from langchain.chains.llm import LLMChain
from langchain.graphs import NetworkxEntityGraph
from langchain.graphs.networkx_graph import KnowledgeTriple, get_entities, parse_triples
from langchain.memory.chat_memory import BaseChatMemory
from langchain.memory.prompt import (
ENTITY_EXTRACTION_PROMPT,
KNOWLEDGE_TRIPLE_EXTRACTION_PROMPT,
)
from langchain.memory.utils import get_prompt_input_key
from langchain.prompts.base import BasePromptTemplate
from langchain.schema import (
BaseMessage,
SystemMessage,
get_buffer_string,
)
[docs]class ConversationKGMemory(BaseChatMemory):
"""Knowledge graph memory for storing conversation memory.
Integrates with external knowledge graph to store and retrieve
information about knowledge triples in the conversation.
"""
k: int = 2
human_prefix: str = "Human"
ai_prefix: str = "AI"
kg: NetworkxEntityGraph = Field(default_factory=NetworkxEntityGraph)
knowledge_extraction_prompt: BasePromptTemplate = KNOWLEDGE_TRIPLE_EXTRACTION_PROMPT
entity_extraction_prompt: BasePromptTemplate = ENTITY_EXTRACTION_PROMPT
llm: BaseLanguageModel
summary_message_cls: Type[BaseMessage] = SystemMessage
"""Number of previous utterances to include in the context."""
memory_key: str = "history" #: :meta private:
[docs] def load_memory_variables(self, inputs: Dict[str, Any]) -> Dict[str, Any]:
"""Return history buffer."""
entities = self._get_current_entities(inputs)
summary_strings = [] | https://python.langchain.com/en/latest/_modules/langchain/memory/kg.html |
304bf7f3d154-1 | entities = self._get_current_entities(inputs)
summary_strings = []
for entity in entities:
knowledge = self.kg.get_entity_knowledge(entity)
if knowledge:
summary = f"On {entity}: {'. '.join(knowledge)}."
summary_strings.append(summary)
context: Union[str, List]
if not summary_strings:
context = [] if self.return_messages else ""
elif self.return_messages:
context = [
self.summary_message_cls(content=text) for text in summary_strings
]
else:
context = "\n".join(summary_strings)
return {self.memory_key: context}
@property
def memory_variables(self) -> List[str]:
"""Will always return list of memory variables.
:meta private:
"""
return [self.memory_key]
def _get_prompt_input_key(self, inputs: Dict[str, Any]) -> str:
"""Get the input key for the prompt."""
if self.input_key is None:
return get_prompt_input_key(inputs, self.memory_variables)
return self.input_key
def _get_prompt_output_key(self, outputs: Dict[str, Any]) -> str:
"""Get the output key for the prompt."""
if self.output_key is None:
if len(outputs) != 1:
raise ValueError(f"One output key expected, got {outputs.keys()}")
return list(outputs.keys())[0]
return self.output_key
[docs] def get_current_entities(self, input_string: str) -> List[str]:
chain = LLMChain(llm=self.llm, prompt=self.entity_extraction_prompt)
buffer_string = get_buffer_string(
self.chat_memory.messages[-self.k * 2 :],
human_prefix=self.human_prefix, | https://python.langchain.com/en/latest/_modules/langchain/memory/kg.html |
304bf7f3d154-2 | human_prefix=self.human_prefix,
ai_prefix=self.ai_prefix,
)
output = chain.predict(
history=buffer_string,
input=input_string,
)
return get_entities(output)
def _get_current_entities(self, inputs: Dict[str, Any]) -> List[str]:
"""Get the current entities in the conversation."""
prompt_input_key = self._get_prompt_input_key(inputs)
return self.get_current_entities(inputs[prompt_input_key])
[docs] def get_knowledge_triplets(self, input_string: str) -> List[KnowledgeTriple]:
chain = LLMChain(llm=self.llm, prompt=self.knowledge_extraction_prompt)
buffer_string = get_buffer_string(
self.chat_memory.messages[-self.k * 2 :],
human_prefix=self.human_prefix,
ai_prefix=self.ai_prefix,
)
output = chain.predict(
history=buffer_string,
input=input_string,
verbose=True,
)
knowledge = parse_triples(output)
return knowledge
def _get_and_update_kg(self, inputs: Dict[str, Any]) -> None:
"""Get and update knowledge graph from the conversation history."""
prompt_input_key = self._get_prompt_input_key(inputs)
knowledge = self.get_knowledge_triplets(inputs[prompt_input_key])
for triple in knowledge:
self.kg.add_triple(triple)
[docs] def save_context(self, inputs: Dict[str, Any], outputs: Dict[str, str]) -> None:
"""Save context from this conversation to buffer."""
super().save_context(inputs, outputs)
self._get_and_update_kg(inputs)
[docs] def clear(self) -> None:
"""Clear memory contents.""" | https://python.langchain.com/en/latest/_modules/langchain/memory/kg.html |
304bf7f3d154-3 | [docs] def clear(self) -> None:
"""Clear memory contents."""
super().clear()
self.kg.clear()
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/memory/kg.html |
561a2d0f6a56-0 | Source code for langchain.memory.buffer
from typing import Any, Dict, List, Optional
from pydantic import root_validator
from langchain.memory.chat_memory import BaseChatMemory, BaseMemory
from langchain.memory.utils import get_prompt_input_key
from langchain.schema import get_buffer_string
[docs]class ConversationBufferMemory(BaseChatMemory):
"""Buffer for storing conversation memory."""
human_prefix: str = "Human"
ai_prefix: str = "AI"
memory_key: str = "history" #: :meta private:
@property
def buffer(self) -> Any:
"""String buffer of memory."""
if self.return_messages:
return self.chat_memory.messages
else:
return get_buffer_string(
self.chat_memory.messages,
human_prefix=self.human_prefix,
ai_prefix=self.ai_prefix,
)
@property
def memory_variables(self) -> List[str]:
"""Will always return list of memory variables.
:meta private:
"""
return [self.memory_key]
[docs] def load_memory_variables(self, inputs: Dict[str, Any]) -> Dict[str, Any]:
"""Return history buffer."""
return {self.memory_key: self.buffer}
[docs]class ConversationStringBufferMemory(BaseMemory):
"""Buffer for storing conversation memory."""
human_prefix: str = "Human"
ai_prefix: str = "AI"
"""Prefix to use for AI generated responses."""
buffer: str = ""
output_key: Optional[str] = None
input_key: Optional[str] = None
memory_key: str = "history" #: :meta private:
@root_validator()
def validate_chains(cls, values: Dict) -> Dict: | https://python.langchain.com/en/latest/_modules/langchain/memory/buffer.html |
561a2d0f6a56-1 | def validate_chains(cls, values: Dict) -> Dict:
"""Validate that return messages is not True."""
if values.get("return_messages", False):
raise ValueError(
"return_messages must be False for ConversationStringBufferMemory"
)
return values
@property
def memory_variables(self) -> List[str]:
"""Will always return list of memory variables.
:meta private:
"""
return [self.memory_key]
[docs] def load_memory_variables(self, inputs: Dict[str, Any]) -> Dict[str, str]:
"""Return history buffer."""
return {self.memory_key: self.buffer}
[docs] def save_context(self, inputs: Dict[str, Any], outputs: Dict[str, str]) -> None:
"""Save context from this conversation to buffer."""
if self.input_key is None:
prompt_input_key = get_prompt_input_key(inputs, self.memory_variables)
else:
prompt_input_key = self.input_key
if self.output_key is None:
if len(outputs) != 1:
raise ValueError(f"One output key expected, got {outputs.keys()}")
output_key = list(outputs.keys())[0]
else:
output_key = self.output_key
human = f"{self.human_prefix}: " + inputs[prompt_input_key]
ai = f"{self.ai_prefix}: " + outputs[output_key]
self.buffer += "\n" + "\n".join([human, ai])
[docs] def clear(self) -> None:
"""Clear memory contents."""
self.buffer = ""
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/memory/buffer.html |
0a4756c71bef-0 | Source code for langchain.memory.readonly
from typing import Any, Dict, List
from langchain.schema import BaseMemory
[docs]class ReadOnlySharedMemory(BaseMemory):
"""A memory wrapper that is read-only and cannot be changed."""
memory: BaseMemory
@property
def memory_variables(self) -> List[str]:
"""Return memory variables."""
return self.memory.memory_variables
[docs] def load_memory_variables(self, inputs: Dict[str, Any]) -> Dict[str, str]:
"""Load memory variables from memory."""
return self.memory.load_memory_variables(inputs)
[docs] def save_context(self, inputs: Dict[str, Any], outputs: Dict[str, str]) -> None:
"""Nothing should be saved or changed"""
pass
[docs] def clear(self) -> None:
"""Nothing to clear, got a memory like a vault."""
pass
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/memory/readonly.html |
cedff6f725f5-0 | Source code for langchain.memory.entity
import logging
from abc import ABC, abstractmethod
from itertools import islice
from typing import Any, Dict, Iterable, List, Optional
from pydantic import BaseModel, Field
from langchain.base_language import BaseLanguageModel
from langchain.chains.llm import LLMChain
from langchain.memory.chat_memory import BaseChatMemory
from langchain.memory.prompt import (
ENTITY_EXTRACTION_PROMPT,
ENTITY_SUMMARIZATION_PROMPT,
)
from langchain.memory.utils import get_prompt_input_key
from langchain.prompts.base import BasePromptTemplate
from langchain.schema import BaseMessage, get_buffer_string
logger = logging.getLogger(__name__)
class BaseEntityStore(BaseModel, ABC):
@abstractmethod
def get(self, key: str, default: Optional[str] = None) -> Optional[str]:
"""Get entity value from store."""
pass
@abstractmethod
def set(self, key: str, value: Optional[str]) -> None:
"""Set entity value in store."""
pass
@abstractmethod
def delete(self, key: str) -> None:
"""Delete entity value from store."""
pass
@abstractmethod
def exists(self, key: str) -> bool:
"""Check if entity exists in store."""
pass
@abstractmethod
def clear(self) -> None:
"""Delete all entities from store."""
pass
[docs]class InMemoryEntityStore(BaseEntityStore):
"""Basic in-memory entity store."""
store: Dict[str, Optional[str]] = {}
[docs] def get(self, key: str, default: Optional[str] = None) -> Optional[str]:
return self.store.get(key, default) | https://python.langchain.com/en/latest/_modules/langchain/memory/entity.html |
cedff6f725f5-1 | return self.store.get(key, default)
[docs] def set(self, key: str, value: Optional[str]) -> None:
self.store[key] = value
[docs] def delete(self, key: str) -> None:
del self.store[key]
[docs] def exists(self, key: str) -> bool:
return key in self.store
[docs] def clear(self) -> None:
return self.store.clear()
[docs]class RedisEntityStore(BaseEntityStore):
"""Redis-backed Entity store. Entities get a TTL of 1 day by default, and
that TTL is extended by 3 days every time the entity is read back.
"""
redis_client: Any
session_id: str = "default"
key_prefix: str = "memory_store"
ttl: Optional[int] = 60 * 60 * 24
recall_ttl: Optional[int] = 60 * 60 * 24 * 3
def __init__(
self,
session_id: str = "default",
url: str = "redis://localhost:6379/0",
key_prefix: str = "memory_store",
ttl: Optional[int] = 60 * 60 * 24,
recall_ttl: Optional[int] = 60 * 60 * 24 * 3,
*args: Any,
**kwargs: Any,
):
try:
import redis
except ImportError:
raise ImportError(
"Could not import redis python package. "
"Please install it with `pip install redis`."
)
super().__init__(*args, **kwargs)
try:
self.redis_client = redis.Redis.from_url(url=url, decode_responses=True) | https://python.langchain.com/en/latest/_modules/langchain/memory/entity.html |
cedff6f725f5-2 | self.redis_client = redis.Redis.from_url(url=url, decode_responses=True)
except redis.exceptions.ConnectionError as error:
logger.error(error)
self.session_id = session_id
self.key_prefix = key_prefix
self.ttl = ttl
self.recall_ttl = recall_ttl or ttl
@property
def full_key_prefix(self) -> str:
return f"{self.key_prefix}:{self.session_id}"
[docs] def get(self, key: str, default: Optional[str] = None) -> Optional[str]:
res = (
self.redis_client.getex(f"{self.full_key_prefix}:{key}", ex=self.recall_ttl)
or default
or ""
)
logger.debug(f"REDIS MEM get '{self.full_key_prefix}:{key}': '{res}'")
return res
[docs] def set(self, key: str, value: Optional[str]) -> None:
if not value:
return self.delete(key)
self.redis_client.set(f"{self.full_key_prefix}:{key}", value, ex=self.ttl)
logger.debug(
f"REDIS MEM set '{self.full_key_prefix}:{key}': '{value}' EX {self.ttl}"
)
[docs] def delete(self, key: str) -> None:
self.redis_client.delete(f"{self.full_key_prefix}:{key}")
[docs] def exists(self, key: str) -> bool:
return self.redis_client.exists(f"{self.full_key_prefix}:{key}") == 1
[docs] def clear(self) -> None:
# iterate a list in batches of size batch_size
def batched(iterable: Iterable[Any], batch_size: int) -> Iterable[Any]:
iterator = iter(iterable) | https://python.langchain.com/en/latest/_modules/langchain/memory/entity.html |
cedff6f725f5-3 | iterator = iter(iterable)
while batch := list(islice(iterator, batch_size)):
yield batch
for keybatch in batched(
self.redis_client.scan_iter(f"{self.full_key_prefix}:*"), 500
):
self.redis_client.delete(*keybatch)
[docs]class SQLiteEntityStore(BaseEntityStore):
"""SQLite-backed Entity store"""
session_id: str = "default"
table_name: str = "memory_store"
def __init__(
self,
session_id: str = "default",
db_file: str = "entities.db",
table_name: str = "memory_store",
*args: Any,
**kwargs: Any,
):
try:
import sqlite3
except ImportError:
raise ImportError(
"Could not import sqlite3 python package. "
"Please install it with `pip install sqlite3`."
)
super().__init__(*args, **kwargs)
self.conn = sqlite3.connect(db_file)
self.session_id = session_id
self.table_name = table_name
self._create_table_if_not_exists()
@property
def full_table_name(self) -> str:
return f"{self.table_name}_{self.session_id}"
def _create_table_if_not_exists(self) -> None:
create_table_query = f"""
CREATE TABLE IF NOT EXISTS {self.full_table_name} (
key TEXT PRIMARY KEY,
value TEXT
)
"""
with self.conn:
self.conn.execute(create_table_query)
[docs] def get(self, key: str, default: Optional[str] = None) -> Optional[str]:
query = f"""
SELECT value | https://python.langchain.com/en/latest/_modules/langchain/memory/entity.html |
cedff6f725f5-4 | query = f"""
SELECT value
FROM {self.full_table_name}
WHERE key = ?
"""
cursor = self.conn.execute(query, (key,))
result = cursor.fetchone()
if result is not None:
value = result[0]
return value
return default
[docs] def set(self, key: str, value: Optional[str]) -> None:
if not value:
return self.delete(key)
query = f"""
INSERT OR REPLACE INTO {self.full_table_name} (key, value)
VALUES (?, ?)
"""
with self.conn:
self.conn.execute(query, (key, value))
[docs] def delete(self, key: str) -> None:
query = f"""
DELETE FROM {self.full_table_name}
WHERE key = ?
"""
with self.conn:
self.conn.execute(query, (key,))
[docs] def exists(self, key: str) -> bool:
query = f"""
SELECT 1
FROM {self.full_table_name}
WHERE key = ?
LIMIT 1
"""
cursor = self.conn.execute(query, (key,))
result = cursor.fetchone()
return result is not None
[docs] def clear(self) -> None:
query = f"""
DELETE FROM {self.full_table_name}
"""
with self.conn:
self.conn.execute(query)
[docs]class ConversationEntityMemory(BaseChatMemory):
"""Entity extractor & summarizer to memory."""
human_prefix: str = "Human"
ai_prefix: str = "AI"
llm: BaseLanguageModel | https://python.langchain.com/en/latest/_modules/langchain/memory/entity.html |
cedff6f725f5-5 | ai_prefix: str = "AI"
llm: BaseLanguageModel
entity_extraction_prompt: BasePromptTemplate = ENTITY_EXTRACTION_PROMPT
entity_summarization_prompt: BasePromptTemplate = ENTITY_SUMMARIZATION_PROMPT
entity_cache: List[str] = []
k: int = 3
chat_history_key: str = "history"
entity_store: BaseEntityStore = Field(default_factory=InMemoryEntityStore)
@property
def buffer(self) -> List[BaseMessage]:
return self.chat_memory.messages
@property
def memory_variables(self) -> List[str]:
"""Will always return list of memory variables.
:meta private:
"""
return ["entities", self.chat_history_key]
[docs] def load_memory_variables(self, inputs: Dict[str, Any]) -> Dict[str, Any]:
"""Return history buffer."""
chain = LLMChain(llm=self.llm, prompt=self.entity_extraction_prompt)
if self.input_key is None:
prompt_input_key = get_prompt_input_key(inputs, self.memory_variables)
else:
prompt_input_key = self.input_key
buffer_string = get_buffer_string(
self.buffer[-self.k * 2 :],
human_prefix=self.human_prefix,
ai_prefix=self.ai_prefix,
)
output = chain.predict(
history=buffer_string,
input=inputs[prompt_input_key],
)
if output.strip() == "NONE":
entities = []
else:
entities = [w.strip() for w in output.split(",")]
entity_summaries = {}
for entity in entities:
entity_summaries[entity] = self.entity_store.get(entity, "")
self.entity_cache = entities
if self.return_messages: | https://python.langchain.com/en/latest/_modules/langchain/memory/entity.html |
cedff6f725f5-6 | self.entity_cache = entities
if self.return_messages:
buffer: Any = self.buffer[-self.k * 2 :]
else:
buffer = buffer_string
return {
self.chat_history_key: buffer,
"entities": entity_summaries,
}
[docs] def save_context(self, inputs: Dict[str, Any], outputs: Dict[str, str]) -> None:
"""Save context from this conversation to buffer."""
super().save_context(inputs, outputs)
if self.input_key is None:
prompt_input_key = get_prompt_input_key(inputs, self.memory_variables)
else:
prompt_input_key = self.input_key
buffer_string = get_buffer_string(
self.buffer[-self.k * 2 :],
human_prefix=self.human_prefix,
ai_prefix=self.ai_prefix,
)
input_data = inputs[prompt_input_key]
chain = LLMChain(llm=self.llm, prompt=self.entity_summarization_prompt)
for entity in self.entity_cache:
existing_summary = self.entity_store.get(entity, "")
output = chain.predict(
summary=existing_summary,
entity=entity,
history=buffer_string,
input=input_data,
)
self.entity_store.set(entity, output.strip())
[docs] def clear(self) -> None:
"""Clear memory contents."""
self.chat_memory.clear()
self.entity_cache.clear()
self.entity_store.clear()
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/memory/entity.html |
790cda312eb1-0 | Source code for langchain.memory.chat_message_histories.cassandra
import json
import logging
from typing import List
from langchain.schema import (
BaseChatMessageHistory,
BaseMessage,
_message_to_dict,
messages_from_dict,
)
logger = logging.getLogger(__name__)
DEFAULT_KEYSPACE_NAME = "chat_history"
DEFAULT_TABLE_NAME = "message_store"
DEFAULT_USERNAME = "cassandra"
DEFAULT_PASSWORD = "cassandra"
DEFAULT_PORT = 9042
[docs]class CassandraChatMessageHistory(BaseChatMessageHistory):
"""Chat message history that stores history in Cassandra.
Args:
contact_points: list of ips to connect to Cassandra cluster
session_id: arbitrary key that is used to store the messages
of a single chat session.
port: port to connect to Cassandra cluster
username: username to connect to Cassandra cluster
password: password to connect to Cassandra cluster
keyspace_name: name of the keyspace to use
table_name: name of the table to use
"""
def __init__(
self,
contact_points: List[str],
session_id: str,
port: int = DEFAULT_PORT,
username: str = DEFAULT_USERNAME,
password: str = DEFAULT_PASSWORD,
keyspace_name: str = DEFAULT_KEYSPACE_NAME,
table_name: str = DEFAULT_TABLE_NAME,
):
self.contact_points = contact_points
self.session_id = session_id
self.port = port
self.username = username
self.password = password
self.keyspace_name = keyspace_name
self.table_name = table_name
try:
from cassandra import (
AuthenticationFailed,
OperationTimedOut,
UnresolvableContactPoints,
) | https://python.langchain.com/en/latest/_modules/langchain/memory/chat_message_histories/cassandra.html |
790cda312eb1-1 | OperationTimedOut,
UnresolvableContactPoints,
)
from cassandra.cluster import Cluster, PlainTextAuthProvider
except ImportError:
raise ValueError(
"Could not import cassandra-driver python package. "
"Please install it with `pip install cassandra-driver`."
)
self.cluster: Cluster = Cluster(
contact_points,
port=port,
auth_provider=PlainTextAuthProvider(
username=self.username, password=self.password
),
)
try:
self.session = self.cluster.connect()
except (
AuthenticationFailed,
UnresolvableContactPoints,
OperationTimedOut,
) as error:
logger.error(
"Unable to establish connection with \
cassandra chat message history database"
)
raise error
self._prepare_cassandra()
def _prepare_cassandra(self) -> None:
"""Create the keyspace and table if they don't exist yet"""
from cassandra import OperationTimedOut, Unavailable
try:
self.session.execute(
f"""CREATE KEYSPACE IF NOT EXISTS
{self.keyspace_name} WITH REPLICATION =
{{ 'class' : 'SimpleStrategy', 'replication_factor' : 1 }};"""
)
except (OperationTimedOut, Unavailable) as error:
logger.error(
f"Unable to create cassandra \
chat message history keyspace: {self.keyspace_name}."
)
raise error
self.session.set_keyspace(self.keyspace_name)
try:
self.session.execute(
f"""CREATE TABLE IF NOT EXISTS
{self.table_name} (id UUID, session_id varchar, | https://python.langchain.com/en/latest/_modules/langchain/memory/chat_message_histories/cassandra.html |
790cda312eb1-2 | {self.table_name} (id UUID, session_id varchar,
history text, PRIMARY KEY ((session_id), id) );"""
)
except (OperationTimedOut, Unavailable) as error:
logger.error(
f"Unable to create cassandra \
chat message history table: {self.table_name}"
)
raise error
@property
def messages(self) -> List[BaseMessage]: # type: ignore
"""Retrieve the messages from Cassandra"""
from cassandra import ReadFailure, ReadTimeout, Unavailable
try:
rows = self.session.execute(
f"""SELECT * FROM {self.table_name}
WHERE session_id = '{self.session_id}' ;"""
)
except (Unavailable, ReadTimeout, ReadFailure) as error:
logger.error("Unable to Retreive chat history messages from cassadra")
raise error
if rows:
items = [json.loads(row.history) for row in rows]
else:
items = []
messages = messages_from_dict(items)
return messages
[docs] def add_message(self, message: BaseMessage) -> None:
"""Append the message to the record in Cassandra"""
import uuid
from cassandra import Unavailable, WriteFailure, WriteTimeout
try:
self.session.execute(
"""INSERT INTO message_store
(id, session_id, history) VALUES (%s, %s, %s);""",
(uuid.uuid4(), self.session_id, json.dumps(_message_to_dict(message))),
)
except (Unavailable, WriteTimeout, WriteFailure) as error:
logger.error("Unable to write chat history messages to cassandra")
raise error | https://python.langchain.com/en/latest/_modules/langchain/memory/chat_message_histories/cassandra.html |
790cda312eb1-3 | logger.error("Unable to write chat history messages to cassandra")
raise error
[docs] def clear(self) -> None:
"""Clear session memory from Cassandra"""
from cassandra import OperationTimedOut, Unavailable
try:
self.session.execute(
f"DELETE FROM {self.table_name} WHERE session_id = '{self.session_id}';"
)
except (Unavailable, OperationTimedOut) as error:
logger.error("Unable to clear chat history messages from cassandra")
raise error
def __del__(self) -> None:
if self.session:
self.session.shutdown()
if self.cluster:
self.cluster.shutdown()
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/memory/chat_message_histories/cassandra.html |
ec5e1d80ddba-0 | Source code for langchain.memory.chat_message_histories.mongodb
import json
import logging
from typing import List
from langchain.schema import (
BaseChatMessageHistory,
BaseMessage,
_message_to_dict,
messages_from_dict,
)
logger = logging.getLogger(__name__)
DEFAULT_DBNAME = "chat_history"
DEFAULT_COLLECTION_NAME = "message_store"
[docs]class MongoDBChatMessageHistory(BaseChatMessageHistory):
"""Chat message history that stores history in MongoDB.
Args:
connection_string: connection string to connect to MongoDB
session_id: arbitrary key that is used to store the messages
of a single chat session.
database_name: name of the database to use
collection_name: name of the collection to use
"""
def __init__(
self,
connection_string: str,
session_id: str,
database_name: str = DEFAULT_DBNAME,
collection_name: str = DEFAULT_COLLECTION_NAME,
):
from pymongo import MongoClient, errors
self.connection_string = connection_string
self.session_id = session_id
self.database_name = database_name
self.collection_name = collection_name
try:
self.client: MongoClient = MongoClient(connection_string)
except errors.ConnectionFailure as error:
logger.error(error)
self.db = self.client[database_name]
self.collection = self.db[collection_name]
self.collection.create_index("SessionId")
@property
def messages(self) -> List[BaseMessage]: # type: ignore
"""Retrieve the messages from MongoDB"""
from pymongo import errors
try:
cursor = self.collection.find({"SessionId": self.session_id})
except errors.OperationFailure as error:
logger.error(error)
if cursor: | https://python.langchain.com/en/latest/_modules/langchain/memory/chat_message_histories/mongodb.html |
ec5e1d80ddba-1 | except errors.OperationFailure as error:
logger.error(error)
if cursor:
items = [json.loads(document["History"]) for document in cursor]
else:
items = []
messages = messages_from_dict(items)
return messages
[docs] def add_message(self, message: BaseMessage) -> None:
"""Append the message to the record in MongoDB"""
from pymongo import errors
try:
self.collection.insert_one(
{
"SessionId": self.session_id,
"History": json.dumps(_message_to_dict(message)),
}
)
except errors.WriteError as err:
logger.error(err)
[docs] def clear(self) -> None:
"""Clear session memory from MongoDB"""
from pymongo import errors
try:
self.collection.delete_many({"SessionId": self.session_id})
except errors.WriteError as err:
logger.error(err)
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/memory/chat_message_histories/mongodb.html |
571095ab28a9-0 | Source code for langchain.memory.chat_message_histories.file
import json
import logging
from pathlib import Path
from typing import List
from langchain.schema import (
BaseChatMessageHistory,
BaseMessage,
messages_from_dict,
messages_to_dict,
)
logger = logging.getLogger(__name__)
[docs]class FileChatMessageHistory(BaseChatMessageHistory):
"""
Chat message history that stores history in a local file.
Args:
file_path: path of the local file to store the messages.
"""
def __init__(self, file_path: str):
self.file_path = Path(file_path)
if not self.file_path.exists():
self.file_path.touch()
self.file_path.write_text(json.dumps([]))
@property
def messages(self) -> List[BaseMessage]: # type: ignore
"""Retrieve the messages from the local file"""
items = json.loads(self.file_path.read_text())
messages = messages_from_dict(items)
return messages
[docs] def add_message(self, message: BaseMessage) -> None:
"""Append the message to the record in the local file"""
messages = messages_to_dict(self.messages)
messages.append(messages_to_dict([message])[0])
self.file_path.write_text(json.dumps(messages))
[docs] def clear(self) -> None:
"""Clear session memory from the local file"""
self.file_path.write_text(json.dumps([]))
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/memory/chat_message_histories/file.html |
bf5d84ee17a4-0 | Source code for langchain.memory.chat_message_histories.redis
import json
import logging
from typing import List, Optional
from langchain.schema import (
BaseChatMessageHistory,
BaseMessage,
_message_to_dict,
messages_from_dict,
)
logger = logging.getLogger(__name__)
[docs]class RedisChatMessageHistory(BaseChatMessageHistory):
def __init__(
self,
session_id: str,
url: str = "redis://localhost:6379/0",
key_prefix: str = "message_store:",
ttl: Optional[int] = None,
):
try:
import redis
except ImportError:
raise ImportError(
"Could not import redis python package. "
"Please install it with `pip install redis`."
)
try:
self.redis_client = redis.Redis.from_url(url=url)
except redis.exceptions.ConnectionError as error:
logger.error(error)
self.session_id = session_id
self.key_prefix = key_prefix
self.ttl = ttl
@property
def key(self) -> str:
"""Construct the record key to use"""
return self.key_prefix + self.session_id
@property
def messages(self) -> List[BaseMessage]: # type: ignore
"""Retrieve the messages from Redis"""
_items = self.redis_client.lrange(self.key, 0, -1)
items = [json.loads(m.decode("utf-8")) for m in _items[::-1]]
messages = messages_from_dict(items)
return messages
[docs] def add_message(self, message: BaseMessage) -> None:
"""Append the message to the record in Redis""" | https://python.langchain.com/en/latest/_modules/langchain/memory/chat_message_histories/redis.html |
bf5d84ee17a4-1 | """Append the message to the record in Redis"""
self.redis_client.lpush(self.key, json.dumps(_message_to_dict(message)))
if self.ttl:
self.redis_client.expire(self.key, self.ttl)
[docs] def clear(self) -> None:
"""Clear session memory from Redis"""
self.redis_client.delete(self.key)
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Jun 07, 2023. | https://python.langchain.com/en/latest/_modules/langchain/memory/chat_message_histories/redis.html |
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