langchain/libs/community/langchain_community/retrievers/knn.py
Bagatur a0c2281540
infra: update mypy 1.10, ruff 0.5 (#23721)
```python
"""python scripts/update_mypy_ruff.py"""
import glob
import tomllib
from pathlib import Path

import toml
import subprocess
import re

ROOT_DIR = Path(__file__).parents[1]


def main():
    for path in glob.glob(str(ROOT_DIR / "libs/**/pyproject.toml"), recursive=True):
        print(path)
        with open(path, "rb") as f:
            pyproject = tomllib.load(f)
        try:
            pyproject["tool"]["poetry"]["group"]["typing"]["dependencies"]["mypy"] = (
                "^1.10"
            )
            pyproject["tool"]["poetry"]["group"]["lint"]["dependencies"]["ruff"] = (
                "^0.5"
            )
        except KeyError:
            continue
        with open(path, "w") as f:
            toml.dump(pyproject, f)
        cwd = "/".join(path.split("/")[:-1])
        completed = subprocess.run(
            "poetry lock --no-update; poetry install --with typing; poetry run mypy . --no-color",
            cwd=cwd,
            shell=True,
            capture_output=True,
            text=True,
        )
        logs = completed.stdout.split("\n")

        to_ignore = {}
        for l in logs:
            if re.match("^(.*)\:(\d+)\: error:.*\[(.*)\]", l):
                path, line_no, error_type = re.match(
                    "^(.*)\:(\d+)\: error:.*\[(.*)\]", l
                ).groups()
                if (path, line_no) in to_ignore:
                    to_ignore[(path, line_no)].append(error_type)
                else:
                    to_ignore[(path, line_no)] = [error_type]
        print(len(to_ignore))
        for (error_path, line_no), error_types in to_ignore.items():
            all_errors = ", ".join(error_types)
            full_path = f"{cwd}/{error_path}"
            try:
                with open(full_path, "r") as f:
                    file_lines = f.readlines()
            except FileNotFoundError:
                continue
            file_lines[int(line_no) - 1] = (
                file_lines[int(line_no) - 1][:-1] + f"  # type: ignore[{all_errors}]\n"
            )
            with open(full_path, "w") as f:
                f.write("".join(file_lines))

        subprocess.run(
            "poetry run ruff format .; poetry run ruff --select I --fix .",
            cwd=cwd,
            shell=True,
            capture_output=True,
            text=True,
        )


if __name__ == "__main__":
    main()

```
2024-07-03 10:33:27 -07:00

108 lines
3.2 KiB
Python

"""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, Iterable, List, Optional
import numpy as np
from langchain_core.callbacks import CallbackManagerForRetrieverRun
from langchain_core.documents import Document
from langchain_core.embeddings import Embeddings
from langchain_core.retrievers import BaseRetriever
def create_index(contexts: List[str], embeddings: Embeddings) -> np.ndarray:
"""
Create an index of embeddings for a list of contexts.
Args:
contexts: List of contexts to embed.
embeddings: Embeddings model to use.
Returns:
Index of embeddings.
"""
with concurrent.futures.ThreadPoolExecutor() as executor:
return np.array(list(executor.map(embeddings.embed_query, contexts)))
class KNNRetriever(BaseRetriever):
"""`KNN` retriever."""
embeddings: Embeddings
"""Embeddings model to use."""
index: Any
"""Index of embeddings."""
texts: List[str]
"""List of texts to index."""
metadatas: Optional[List[dict]] = None
"""List of metadatas corresponding with each text."""
k: int = 4
"""Number of results to return."""
relevancy_threshold: Optional[float] = None
"""Threshold for relevancy."""
class Config:
"""Configuration for this pydantic object."""
arbitrary_types_allowed = True
@classmethod
def from_texts(
cls,
texts: List[str],
embeddings: Embeddings,
metadatas: Optional[List[dict]] = None,
**kwargs: Any,
) -> KNNRetriever:
index = create_index(texts, embeddings)
return cls(
embeddings=embeddings,
index=index,
texts=texts,
metadatas=metadatas,
**kwargs,
)
@classmethod
def from_documents(
cls,
documents: Iterable[Document],
embeddings: Embeddings,
**kwargs: Any,
) -> KNNRetriever:
texts, metadatas = zip(*((d.page_content, d.metadata) for d in documents))
return cls.from_texts(
texts=texts, embeddings=embeddings, metadatas=metadatas, **kwargs
)
def _get_relevant_documents(
self, query: str, *, run_manager: CallbackManagerForRetrieverRun
) -> 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)
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],
metadata=self.metadatas[row] if self.metadatas else {},
)
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