Connect to Azure Cosmos DB for NoSQL with the SDK

The Azure SDK for Python is a suite of client libraries that provides a consistent developer interface to interact with many Azure services. Client libraries are packages that you would use to consume these resources and interact with them.

In this lab, you’ll connect to an Azure Cosmos DB for NoSQL account using the Azure SDK for Python.

Prepare your development environment

If you have not already cloned the lab code repository for Build copilots with Azure Cosmos DB and set up your local environment, view the Setup local lab environment instructions to do so.

Create an Azure Cosmos DB for NoSQL account

If you already created an Azure Cosmos DB for NoSQL account for the Build copilots with Azure Cosmos DB labs on this site, you can use it for this lab and skip ahead to the next section. Otherwise, view the Setup Azure Cosmos DB instructions to create an Azure Cosmos DB for NoSQL account that you will use throughout the lab modules and grant your user identity access to manage data in the account by assigning it to the Cosmos DB Built-in Data Contributor role.

Install the azure-cosmos library

The azure-cosmos library is available on PyPI for easy installation into your Python projects.

In Visual Studio Code, in the Explorer pane, browse to the python/01-sdk-connect folder.
Open the context menu for the python/01-sdk-connect folder and then select Open in Integrated Terminal to open a new terminal instance.

📝 This command will open the terminal with the starting directory already set to the python/01-sdk-connect folder.

Create and activate a virtual environment to manage dependencies:

python -m venv venv
source venv/bin/activate   # On Windows, use `venv\Scripts\activate`

Install the azure-cosmos package using the following command:
```
pip install azure-cosmos
```
Install the azure-identity library, which allows us to use Azure authentication to connect to the Azure Cosmos DB workspace, using the following command:
```
pip install azure-identity
```
Close the integrated terminal.

Use the azure-cosmos library

Once the Azure Cosmos DB library from the Azure SDK for Python has been imported, you can immediately use its classes to connect to an Azure Cosmos DB for NoSQL account. The CosmosClient class is the core class used to make the initial connection to an Azure Cosmos DB for NoSQL account.

In Visual Studio Code, in the Explorer pane, browse to the python/01-sdk-connect folder.
Open the blank Python file named script.py.
Add the following import statement to import the CosmosClient and the DefaultAzureCredential classes:
```
from azure.cosmos import CosmosClient
from azure.identity import DefaultAzureCredential
```
Add variables named endpoint and credential and set the endpoint value to the endpoint of the Azure Cosmos DB account you created earlier. The credential variable should be set to a new instance of the DefaultAzureCredential class:
```
endpoint = "<cosmos-endpoint>"
credential = DefaultAzureCredential()
```
📝 For example, if your endpoint is: https://dp420.documents.azure.com:443/, the statement would be: endpoint = “https://dp420.documents.azure.com:443/”.
Add a new variable named client and initialize it as a new instance of the CosmosClient class using the endpoint and credential variables:
```
client = CosmosClient(endpoint, credential=credential)
```

Add a function named main to read and print account properties:

def main():
    account_info = client.get_database_account()
    print(f"Consistency Policy:	{account_info.ConsistencyPolicy}")
    print(f"Primary Region: {account_info.WritableLocations[0]['name']}")

if __name__ == "__main__":
    main()

Your script.py file should now look like this:

from azure.cosmos import CosmosClient
from azure.identity import DefaultAzureCredential

endpoint = "<cosmos-endpoint>"
credential = DefaultAzureCredential()

client = CosmosClient(endpoint, credential=credential)

def main():
    account_info = client.get_database_account()
    print(f"Consistency Policy:	{account_info.ConsistencyPolicy}")
    print(f"Primary Region: {account_info.WritableLocations[0]['name']}")

if __name__ == "__main__":
    main()

Save the script.py file.

Test the script

Now that the Python code to connect to the Azure Cosmos DB for NoSQL account is complete, you can test the script. This script will print the default consistency level and the name of the first writable region. When you created the account, you specified a location, and you should expect to see that same location value printed as the result of this script.

In Visual Studio Code, open the context menu for the python/01-sdk-connect folder and then select Open in Integrated Terminal to open a new terminal instance.
Before running the script, you must log into Azure using the az login command. At the terminal window, run:
```
az login
```
Run the script using the python command:
```
python script.py
```
The script will now output the default consistency level and the first writable region. For example, if the default consistency level for the account is Session, and the first writable region was East US, the script would output:
```
Consistency Policy:   {'defaultConsistencyLevel': 'Session'}
Primary Region: East US
```
Close the integrated terminal.
Close Visual Studio Code.