langchain/libs/community/langchain_community/retrievers/nanopq.py
Eugene Yurtsev bf5193bb99
community[patch]: Upgrade pydantic extra (#25185)
Upgrade to using a literal for specifying the extra which is the
recommended approach in pydantic 2.

This works correctly also in pydantic v1.

```python
from pydantic.v1 import BaseModel

class Foo(BaseModel, extra="forbid"):
    x: int

Foo(x=5, y=1)
```

And 


```python
from pydantic.v1 import BaseModel

class Foo(BaseModel):
    x: int

    class Config:
      extra = "forbid"

Foo(x=5, y=1)
```


## Enum -> literal using grit pattern:

```
engine marzano(0.1)
language python
or {
    `extra=Extra.allow` => `extra="allow"`,
    `extra=Extra.forbid` => `extra="forbid"`,
    `extra=Extra.ignore` => `extra="ignore"`
}
```

Resorted attributes in config and removed doc-string in case we will
need to deal with going back and forth between pydantic v1 and v2 during
the 0.3 release. (This will reduce merge conflicts.)


## Sort attributes in Config:

```
engine marzano(0.1)
language python


function sort($values) js {
    return $values.text.split(',').sort().join("\n");
}


class_definition($name, $body) as $C where {
    $name <: `Config`,
    $body <: block($statements),
    $values = [],
    $statements <: some bubble($values) assignment() as $A where {
        $values += $A
    },
    $body => sort($values),
}

```
2024-08-08 17:20:39 +00:00

124 lines
3.8 KiB
Python

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 NanoPQRetriever(BaseRetriever):
"""`NanoPQ 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."""
subspace: int = 4
"""No of subspaces to be created, should be a multiple of embedding shape"""
clusters: int = 128
"""No of clusters to be created"""
class Config:
arbitrary_types_allowed = True
@classmethod
def from_texts(
cls,
texts: List[str],
embeddings: Embeddings,
metadatas: Optional[List[dict]] = None,
**kwargs: Any,
) -> NanoPQRetriever:
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,
) -> NanoPQRetriever:
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]:
try:
from nanopq import PQ
except ImportError:
raise ImportError(
"Could not import nanopq, please install with `pip install " "nanopq`."
)
query_embeds = np.array(self.embeddings.embed_query(query))
try:
pq = PQ(M=self.subspace, Ks=self.clusters, verbose=True).fit(
self.index.astype("float32")
)
except AssertionError:
error_message = (
"Received params: training_sample={training_sample}, "
"n_cluster={n_clusters}, subspace={subspace}, "
"embedding_shape={embedding_shape}. Issue with the combination. "
"Please retrace back to find the exact error"
).format(
training_sample=self.index.shape[0],
n_clusters=self.clusters,
subspace=self.subspace,
embedding_shape=self.index.shape[1],
)
raise RuntimeError(error_message)
index_code = pq.encode(vecs=self.index.astype("float32"))
dt = pq.dtable(query=query_embeds.astype("float32"))
dists = dt.adist(codes=index_code)
sorted_ix = np.argsort(dists)
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]
]
return top_k_results