Updated on 2024-10-12 GMT+08:00

Client Code Sample for Vector Search (Python)

OpenSearch provides standard REST APIs and clients developed using Java and Python.

This section provides a sample of Python code for creating vector indexes, and importing and querying vector data. It shows how to use the client to implement vector search.

Prerequisites

The Python dependency package has been installed on the client. If it is not installed, run the following command to install it:

pip install opensearch-py==1.1.0

Sample Code

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from opensearchpy import OpenSearch

# Create a client.
def get_client(hosts: list, user: str = None, password: str = None):
    if user and password:
        return OpenSearch(hosts, http_auth=(user, password), verify_certs=False, ssl_show_warn=False)
    else:
        return OpenSearch(hosts)

# Create an index table.
def create(client: OpenSearch, index: str):
    # Index mapping information
    index_mapping = {
        "settings": {
            "index": {
                "vector": "true",  # Enable the vector feature.
                "number_of_shards": 1,  # Set the number of index shards as needed.
                "number_of_replicas": 0,  # Set the number of index replicas as needed.
            }
        },
        "mappings": {
            "properties": {
                "my_vector": {
                    "type": "vector",
                    "dimension": 2,
                    "indexing": True,
                    "algorithm": "GRAPH",
                    "metric": "euclidean"
                }
                # Other fields can be added if necessary.
            }
        }
    }
    res = client.indices.create(index=index, body=index_mapping)
    print("create index result: ", res)

# Write data.
def write(client: OpenSearch, index: str, vecs: list, bulk_size=500):
    for i in range(0, len(vecs), bulk_size):
        actions = ""
        for vec in vecs[i: i + bulk_size]:
            actions += '{"index": {"_index": "%s"}}\n' % index
            actions += '{"my_vector": %s}\n' % str(vec)
        client.bulk(body=actions, request_timeout=3600)
    client.indices.refresh(index=index, request_timeout=3600)
    print("write index success!")

# Query a vector index.
def search(client: OpenSearch, index: str, query: list[float], size: int):
    # Query statement. Select an appropriate query method.
    query_body = {
        "size": size,
        "query": {
            "vector": {
                "my_vector": {
                    "vector": query,
                    "topk": size
                }
            }
        }
    }
    res = client.search(index=index, body=query_body)
    print("search index result: ", res)

# Delete an index.
def delete(client: OpenSearch, index: str):
    res = client.indices.delete(index=index)
    print("delete index result: ", res)

if __name__ == '__main__':
    os_client = get_client(hosts=['http://x.x.x.x:9200'])

    # For a security-mode cluster with HTTPS enabled, run the following:
    # os_client = get_client(hosts=['https://x.x.x.x:9200', 'https://x.x.x.x:9200'], user='xxxxx', password='xxxxx')

    # For a security-mode cluster with HTTPS disabled, run the following:
    # os_client = get_client(hosts=['http://x.x.x.x:9200', 'http://x.x.x.x:9200'], user='xxxxx', password='xxxxx')

    # Test the index name.
    index_name = "my_index"

    # Create an index.
    create(os_client, index=index_name)

    # Write data.
    data = [[1.0, 1.0], [2.0, 2.0], [3.0, 3.0]]
    write(os_client, index=index_name, vecs=data)

    # Query an index.
    query_vector = [1.0, 1.0]
    search(os_client, index=index_name, query=query_vector, size=3)

    # Delete an index.
    delete(os_client, index=index_name)