langchain/libs/community/langchain_community/document_loaders/mongodb.py
Kushagra b1f22bf76c
community[minor]: added a feature to filter documents in Mongoloader (#18253)
"community: added a feature to filter documents in Mongoloader"
- **Description:** added a feature to filter documents in Mongoloader
    - **Feature:** the feature #18251
    - **Dependencies:** No
    - **Twitter handle:** https://twitter.com/im_Kushagra
2024-03-08 12:06:35 -08:00

95 lines
3.1 KiB
Python

import asyncio
import logging
from typing import Dict, List, Optional, Sequence
from langchain_core.documents import Document
from langchain_community.document_loaders.base import BaseLoader
logger = logging.getLogger(__name__)
class MongodbLoader(BaseLoader):
"""Load MongoDB documents."""
def __init__(
self,
connection_string: str,
db_name: str,
collection_name: str,
*,
filter_criteria: Optional[Dict] = None,
field_names: Optional[Sequence[str]] = None,
) -> None:
try:
from motor.motor_asyncio import AsyncIOMotorClient
except ImportError as e:
raise ImportError(
"Cannot import from motor, please install with `pip install motor`."
) from e
if not connection_string:
raise ValueError("connection_string must be provided.")
if not db_name:
raise ValueError("db_name must be provided.")
if not collection_name:
raise ValueError("collection_name must be provided.")
self.client = AsyncIOMotorClient(connection_string)
self.db_name = db_name
self.collection_name = collection_name
self.field_names = field_names
self.filter_criteria = filter_criteria or {}
self.db = self.client.get_database(db_name)
self.collection = self.db.get_collection(collection_name)
def load(self) -> List[Document]:
"""Load data into Document objects.
Attention:
This implementation starts an asyncio event loop which
will only work if running in a sync env. In an async env, it should
fail since there is already an event loop running.
This code should be updated to kick off the event loop from a separate
thread if running within an async context.
"""
return asyncio.run(self.aload())
async def aload(self) -> List[Document]:
"""Load data into Document objects."""
result = []
total_docs = await self.collection.count_documents(self.filter_criteria)
# Construct the projection dictionary if field_names are specified
projection = (
{field: 1 for field in self.field_names} if self.field_names else None
)
async for doc in self.collection.find(self.filter_criteria, projection):
metadata = {
"database": self.db_name,
"collection": self.collection_name,
}
# Extract text content from filtered fields or use the entire document
if self.field_names is not None:
fields = {name: doc[name] for name in self.field_names}
texts = [str(value) for value in fields.values()]
text = " ".join(texts)
else:
text = str(doc)
result.append(Document(page_content=text, metadata=metadata))
if len(result) != total_docs:
logger.warning(
f"Only partial collection of documents returned. "
f"Loaded {len(result)} docs, expected {total_docs}."
)
return result