Python driver quickstart

This driver doesn’t support the vector data type.

DataStax recommends CQL drivers only for Serverless (Non-Vector) databases, existing applications that previously used a CQL-based driver, or if you plan to exclusively use CQL.

It is possible to use CQL drivers for non-vector data in Serverless (Vector) databases. However, DataStax recommends the Data API and clients for Serverless (Vector) databases.

To determine the option that best suits your use case, see Compare connection methods.

This quickstart explains how to use the Python driver to connect to your database, load a set of vector embeddings, and perform a similarity search to find vectors that are close to the one in your query.

Prerequisites

An active Astra account
An active Serverless (Non-Vector) database
A Secure Connect Bundle (SCB)
An application token
Python 3.7 or later

Install the `cassandra-driver` package

Check your pip version and, if necessary, upgrade pip before you install the cassandra-driver package.

Verify that pip is version 23.0 or later:
```
pip --version
```
Upgrade pip, if needed:
```
python -m pip install --upgrade pip
```
Install the cassandra-driver package:
```
pip install cassandra-driver
```

Import libraries and connect to the database

Import the necessary libraries and establish a connection to your database.

DataStax recommends this basic configuration for use cases that are not proofs of concept or for production use. For proofs of concept or production use, see Production configuration.

import os
from cassandra.cluster import Cluster
from cassandra.auth import PlainTextAuthProvider

session = Cluster(
    cloud={"secure_connect_bundle": os.environ["ASTRA_DB_SECURE_BUNDLE_PATH"]},
    auth_provider=PlainTextAuthProvider("token", os.environ["ASTRA_DB_APPLICATION_TOKEN"]),
).connect()

After you connect to the database, you can use the driver to perform operations on your database.

Create a table and vector-compatible Storage Attached Index (SAI)

Create a table named vector_test in your database with columns for an integer id, text, and a 5-dimensional vector.

Then, create a custom index on the vector column of this table using a storage-attached index with a dot product similarity function for efficient vector searches.

keyspace = "default_keyspace"
v_dimension = 5

session.execute((
    "CREATE TABLE IF NOT EXISTS {keyspace}.vector_test (id INT PRIMARY KEY, "
    "text TEXT, vector VECTOR<FLOAT,{v_dimension}>);"
).format(keyspace=keyspace, v_dimension=v_dimension))

session.execute((
    "CREATE CUSTOM INDEX IF NOT EXISTS idx_vector_test "
    "ON {keyspace}.vector_test "
    "(vector) USING 'StorageAttachedIndex' WITH OPTIONS = "
    "{{'similarity_function' : 'cosine'}};"
).format(keyspace=keyspace))

Load data

Insert a few documents with embeddings into the collection.

text_blocks = [
    (1, "Chat bot integrated sneakers that talk to you", [0.1, 0.15, 0.3, 0.12, 0.05]),
    (2, "An AI quilt to help you sleep forever", [0.45, 0.09, 0.01, 0.2, 0.11]),
    (3, "A deep learning display that controls your mood", [0.1, 0.05, 0.08, 0.3, 0.6]),
]
for block in text_blocks:
    id, text, vector = block
    session.execute(
        f"INSERT INTO {keyspace}.vector_test (id, text, vector) VALUES (%s, %s, %s)",
        (id, text, vector)
    )

Perform a similarity search

Find documents that are close to a specific vector embedding.

ann_query = (
    f"SELECT id, text, similarity_cosine(vector, [0.15, 0.1, 0.1, 0.35, 0.55]) as sim FROM {keyspace}.vector_test "
    "ORDER BY vector ANN OF [0.15, 0.1, 0.1, 0.35, 0.55] LIMIT 2"
)
for row in session.execute(ann_query):
    print(f"[{row.id}] \"{row.text}\" (sim: {row.sim:.4f})")

Migrate the Python driver

If necessary, you can migrate an earlier DataStax Python driver to a version that can connect to your Astra DB database.

Complete the prerequisites.
Install the latest Python driver package.

In your existing DataStax Python driver code, modify the connection code to use the SCB credentials.

In the cloud_config parameter, include the path to the SCB for your Astra DB database (secure-connect-DATABASE_NAME.zip).

from cassandra.cluster import Cluster
from cassandra.auth import PlainTextAuthProvider

cloud_config= {
        'secure_connect_bundle': '/SECURE_CONNECT_BUNDLE_PATH/secure-connect-DATABASE_NAME.zip'
        }
auth_provider = PlainTextAuthProvider('clientId', 'clientSecret')
cluster = Cluster(cloud=cloud_config, auth_provider=auth_provider)
session = cluster.connect()

Run your Python script to connect to your database.