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AstraDB

DataStax Astra DB is a serverless vector-capable database built on Cassandra and made conveniently available through an easy-to-use JSON API.

Overview​

The AstraDB Document Loader returns a list of Langchain Documents from an AstraDB database.

The Loader takes the following parameters:

  • api_endpoint: AstraDB API endpoint. Looks like https://01234567-89ab-cdef-0123-456789abcdef-us-east1.apps.astra.datastax.com
  • token: AstraDB token. Looks like AstraCS:6gBhNmsk135....
  • collection_name : AstraDB collection name
  • namespace: (Optional) AstraDB namespace
  • filter_criteria: (Optional) Filter used in the find query
  • projection: (Optional) Projection used in the find query
  • find_options: (Optional) Options used in the find query
  • nb_prefetched: (Optional) Number of documents pre-fetched by the loader
  • extraction_function: (Optional) A function to convert the AstraDB document to the LangChain page_content string. Defaults to json.dumps

The following metadata is set to the LangChain Documents metadata output:

{
    metadata : {
        "namespace": "...", 
        "api_endpoint": "...", 
        "collection": "..."
    }
}

Load documents with the Document Loader​

from langchain_community.document_loaders 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 = ")
loader = AstraDBLoader(
    api_endpoint=ASTRA_DB_API_ENDPOINT,
    token=ASTRA_DB_APPLICATION_TOKEN,
    collection_name="movie_reviews",
    projection={"title": 1, "reviewtext": 1},
    find_options={"limit": 10},
)
docs = loader.load()
docs[0]
Document(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?"}', metadata={'namespace': 'default_keyspace', 'api_endpoint': 'https://01234567-89ab-cdef-0123-456789abcdef-us-east1.apps.astra.datastax.com', 'collection': 'movie_reviews'})

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