DataStax Astra DB is a serverless AI-ready database built on Apache Cassandra® and made conveniently available through an easy-to-use JSON API.

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Overview

The Astra DB Document Loader returns a list of Langchain Document objects read from an Astra DB collection. The loader takes the following parameters:
  • api_endpoint: Astra DB API endpoint. Looks like https://01234567-89ab-cdef-0123-456789abcdef-us-east1.apps.astra.datastax.com
  • token: Astra DB token. Looks like AstraCS:aBcD0123...
  • collection_name : AstraDB collection name
  • namespace: (Optional) AstraDB namespace (called keyspace in Astra DB)
  • filter_criteria: (Optional) Filter used in the find query
  • projection: (Optional) Projection used in the find query
  • limit: (Optional) Maximum number of documents to retrieve
  • extraction_function: (Optional) A function to convert the AstraDB document to the LangChain page_content string. Defaults to json.dumps
The loader sets the following metadata for the documents it reads: 
metadata={
    "namespace": "...", 
    "api_endpoint": "...", 
    "collection": "..."
}

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Setup

!pip install "langchain-astradb>=0.6,<0.7"

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Load documents with the Document Loader

from langchain_astradb import AstraDBLoader
API Reference: AstraDBLoader 
from getpass import getpass

ASTRA_DB_API_ENDPOINT = input("ASTRA_DB_API_ENDPOINT = ")
ASTRA_DB_APPLICATION_TOKEN = getpass("ASTRA_DB_APPLICATION_TOKEN = ")

ASTRA_DB_API_ENDPOINT =  https://01234567-89ab-cdef-0123-456789abcdef-us-east1.apps.astra.datastax.com
ASTRA_DB_APPLICATION_TOKEN =  ········

loader = AstraDBLoader(
    api_endpoint=ASTRA_DB_API_ENDPOINT,
    token=ASTRA_DB_APPLICATION_TOKEN,
    collection_name="movie_reviews",
    projection={"title": 1, "reviewtext": 1},
    limit=10,
)

docs = loader.load()

docs[0]

Document(metadata={'namespace': 'default_keyspace', 'api_endpoint': 'https://01234567-89ab-cdef-0123-456789abcdef-us-east1.apps.astra.datastax.com', 'collection': 'movie_reviews'}, page_content='{"_id": "659bdffa16cbc4586b11a423", "title": "Dangerous Men", "reviewtext": "\\"Dangerous Men,\\" the picture\'s production notes inform, took 26 years to reach the big screen. After having seen it, I wonder: What was the rush?"}')