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Quickstart: Azure Cosmos DB for Apache Gremlin client library for Python

Get started with the Azure Cosmos DB for Apache Gremlin client library for Python to store, manage, and query unstructured data. Follow the steps in this guide to create a new account, install a Python client library, connect to the account, perform common operations, and query your final sample data.

Library source code | Package (PyPi)

Prerequisites

  • An Azure subscription

    • If you don't have an Azure subscription, create a free account before you begin.
  • Python 3.12 or later

Setting up

First, set up the account and development environment for this guide. This section walks you through the process of creating an account, getting its credentials, and then preparing your development environment.

Create an account

Start by creating an API for Apache Gremlin account. Once the account is created, create the database and graph resources.

  1. If you don't already have a target resource group, use the az group create command to create a new resource group in your subscription.

    az group create \
        --name "<resource-group-name>" \
        --location "<location>"
    
  2. Use the az cosmosdb create command to create a new Azure Cosmos DB for Apache Gremlin account with default settings.

    az cosmosdb create \
        --resource-group "<resource-group-name>" \
        --name "<account-name>" \
        --locations "regionName=<location>" \
        --capabilities "EnableGremlin"
    
  3. Create a new database using az cosmosdb gremlin database create named cosmicworks.

    az cosmosdb gremlin database create \
        --resource-group "<resource-group-name>" \
        --account-name "<account-name>" \
        --name "cosmicworks"
    
  4. Use the az cosmosdb gremlin graph create command to create a new graph named products.

    az cosmosdb gremlin graph create \
        --resource-group "<resource-group-name>" \
        --account-name "<account-name>" \
        --database-name "cosmicworks" \
        --name "products" \
        --partition-key-path "/category"
    

Get credentials

Now, get the password for the client library to use to create a connection to the recently created account.

  1. Use az cosmosdb show to get the host for the account.

    az cosmosdb show \
        --resource-group "<resource-group-name>" \
        --name "<account-name>" \
        --query "{host:name}"
    
  2. Record the value of the host property from the previous commands' output. This property' value is the host you use later in this guide to connect to the account with the library.

  3. Use az cosmosdb keys list to get the keys for the account.

    az cosmosdb keys list \
        --resource-group "<resource-group-name>" \
        --name "<account-name>" \
        --type "keys"
    
  4. Record the value of the primaryMasterKey property from the previous commands' output. This property's value is the key you use later in this guide to connect to the account with the library.

Prepare development environment

Then, configure your development environment with a new project and the client library. This step is the last required prerequisite before moving on to the rest of this guide.

  1. Start in an empty folder.

  2. Import the gremlinpython package from Python Package Index (PyPI).

    pip install gremlinpython
    
  3. Create the app.py file.

Object model

Description
GremlinClient Represents the client used to connect and interact with the Gremlin server
GraphTraversalSource Used to construct and execute Gremlin traversals

Code examples

Authenticate client

Start by authenticating the client using the credentials gathered earlier in this guide.

  1. Open the app.py file in your integrated development environment (IDE).

  2. Import the following types from the gremlin_python.driver library:

    • gremlin_python.driver.client
    • gremlin_python.driver.serializer
    from gremlin_python.driver import client, serializer
    
  3. Create string variables for the credentials collected earlier in this guide. Name the variables hostname and primary_key.

    hostname = "<host>"
    primary_key = "<key>"
    
  4. Create a Client object using the credentials and configuration variables created in the previous steps. Name the variable client.

    client = client.Client(
        url=f"wss://{hostname}.gremlin.cosmos.azure.com:443/",
        traversal_source="g",
        username="/dbs/cosmicworks/colls/products",
        password=f"{primary_key}",
        message_serializer=serializer.GraphSONSerializersV2d0()
    )
    

Insert data

Next, insert new vertex and edge data into the graph. Before creating the new data, clear the graph of any existing data.

  1. Run the g.V().drop() query to clear all vertices and edges from the graph.

    client.submit("g.V().drop()").all().result()
    
  2. Create a Gremlin query that adds a vertex.

    insert_vertex_query = (
        "g.addV('product')"
        ".property('id', prop_id)"
        ".property('name', prop_name)"
        ".property('category', prop_category)"
        ".property('quantity', prop_quantity)"
        ".property('price', prop_price)"
        ".property('clearance', prop_clearance)"
    )
    
  3. Add a vertex for a single product.

    client.submit(
        message=insert_vertex_query,
        bindings={
            "prop_id": "aaaaaaaa-0000-1111-2222-bbbbbbbbbbbb",
            "prop_name": "Yamba Surfboard",
            "prop_category": "gear-surf-surfboards",
            "prop_quantity": 12,
            "prop_price": 850.00,
            "prop_clearance": False,
        },
    ).all().result()
    
  4. Add two more vertices for two extra products.

    client.submit(
        message=insert_vertex_query,
        bindings={
            "prop_id": "bbbbbbbb-1111-2222-3333-cccccccccccc",
            "prop_name": "Montau Turtle Surfboard",
            "prop_category": "gear-surf-surfboards",
            "prop_quantity": 5,
            "prop_price": 600.00,
            "prop_clearance": True,
        },
    ).all().result()
    
    client.submit(
        message=insert_vertex_query,
        bindings={
            "prop_id": "cccccccc-2222-3333-4444-dddddddddddd",
            "prop_name": "Noosa Surfboard",
            "prop_category": "gear-surf-surfboards",
            "prop_quantity": 31,
            "prop_price": 1100.00,
            "prop_clearance": False,
        },
    ).all().result()
    
  5. Create another Gremlin query that adds an edge.

    insert_edge_query = (
        "g.V([prop_partition_key, prop_source_id])"
        ".addE('replaces')"
        ".to(g.V([prop_partition_key, prop_target_id]))"
    )
    
  6. Add two edges.

    client.submit(
        message=insert_edge_query,
        bindings={
            "prop_partition_key": "gear-surf-surfboards",
            "prop_source_id": "bbbbbbbb-1111-2222-3333-cccccccccccc",
            "prop_target_id": "aaaaaaaa-0000-1111-2222-bbbbbbbbbbbb",
        },
    ).all().result()
    
    client.submit(
        message=insert_edge_query,
        bindings={
            "prop_partition_key": "gear-surf-surfboards",
            "prop_source_id": "bbbbbbbb-1111-2222-3333-cccccccccccc",
            "prop_target_id": "cccccccc-2222-3333-4444-dddddddddddd",
        },
    ).all().result()
    

Read data

Then, read data that was previously inserted into the graph.

  1. Create a query that reads a vertex using the unique identifier and partition key value.

    read_vertex_query = "g.V([prop_partition_key, prop_id])"
    
  2. Then, read a vertex by supplying the required parameters.

    matched_item = client.submit(
        message=read_vertex_query,
        bindings={
            "prop_partition_key": "gear-surf-surfboards",
            "prop_id": "aaaaaaaa-0000-1111-2222-bbbbbbbbbbbb"
        }
    ).one()
    

Query data

Finally, use a query to find all data that matches a specific traversal or filter in the graph.

  1. Create a query that finds all vertices that traverse out from a specific vertex.

    find_vertices_query = (
        "g.V().hasLabel('product')"
        ".has('category', prop_partition_key)"
        ".has('name', prop_name)"
        ".outE('replaces').inV()"
    )
    
  2. Execute the query specifying the Montau Turtle Surfboard product.

    find_results = client.submit(
        message=find_vertices_query,
        bindings={
            "prop_partition_key": "gear-surf-surfboards",
            "prop_name": "Montau Turtle Surfboard",
        },
    ).all().result()
    
  3. Iterate over the query results.

    for result in find_results:
        # Do something here with each result
    

Run the code

Run the newly created application using a terminal in your application directory.

python app.py

Clean up resources

When you no longer need the account, remove the account from your Azure subscription by deleting the resource.

az cosmosdb delete \
    --resource-group "<resource-group-name>" \
    --name "<account-name>"

Next step