Create and update documents with the Azure Cosmos DB for NoSQL SDK

The azure-cosmos library includes methods to create, retrieve, update, and delete (CRUD) items within an Azure Cosmos DB for NoSQL container. Together, these methods perform some of the most common “CRUD” operations across various items within NoSQL API containers.

In this lab, you’ll use the Python SDK to perform everyday CRUD operations on an item within an Azure Cosmos DB for NoSQL container.

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/03-sdk-crud folder.
Open the context menu for the python/03-sdk-crud 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/03-sdk-crud 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
```
Since we are using the asynchronous version of the SDK, we need to install the asyncio library as well:
```
pip install asyncio
```
The asynchronous version of the SDK also requires the aiohttp library. Install it using the following command:
```
pip install aiohttp
```
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
```

Use the azure-cosmos library

Using the credentials from the newly created account, you will connect with the SDK classes and create a new database and container instance. Then, you will use the Data Explorer to validate that the instances exist in the Azure portal.

In Visual Studio Code, in the Explorer pane, browse to the python/03-sdk-crud folder.
Open the blank Python file named script.py.
Add the following import statement to import the PartitionKey class:
```
from azure.cosmos import PartitionKey
```
Add the following import statements to import the asynchronous CosmosClient class, DefaultAzureCredential class, and the asyncio library:
```
from azure.cosmos.aio import CosmosClient
from azure.identity.aio import DefaultAzureCredential
import asyncio
```
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/”.
All interaction with Cosmos DB starts with an instance of the CosmosClient. In order to use the asynchronous client, we need to use async/await keywords, which can only be used within async methods. Create a new async method named main and add the following code to create a new instance of the asynchronous CosmosClient class using the endpoint and credential variables:
```
async def main():
    async with CosmosClient(endpoint, credential=credential) as client:
```
💡 Since we’re using the asynchronous CosmosClient client, in order to properly use it you also have to warm it up and close it down. We recommend using the async with keywords as demonstrated in the code above to start your clients - these keywords create a context manager that automatically warms up, initializes, and cleans up the client, so you don’t have to.

Add the following code to create a database and container if they do not already exist:

# Create database
database = await client.create_database_if_not_exists(id="cosmicworks")
    
# Create container
container = await database.create_container_if_not_exists(
    id="products",
    partition_key=PartitionKey(path="/categoryId"),
    offer_throughput=400
)

Underneath the main method, add the following code to run the main method using the asyncio library:
```
if __name__ == "__main__":
    asyncio.run(query_items_async())
```

Your script.py file should now look like this:

from azure.cosmos import PartitionKey
from azure.cosmos.aio import CosmosClient
from azure.identity.aio import DefaultAzureCredential
import asyncio

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

async def main():
    async with CosmosClient(endpoint, credential=credential) as client:
        # Create database
        database = await client.create_database_if_not_exists(id="cosmicworks")
    
        # Create container
        container = await database.create_container_if_not_exists(
            id="products",
            partition_key=PartitionKey(path="/categoryId")
        )

if __name__ == "__main__":
    asyncio.run(main())

Save the script.py file.
Before running the script, you must log into Azure using the az login command. At the terminal window, run:
```
az login
```
Run the script to create the database and container:
```
python script.py
```
Switch to your web browser window.
Within the Azure Cosmos DB account resource, navigate to the Data Explorer pane.
In the Data Explorer, expand the cosmicworks database node, then observe the new products container node within the NOSQL API navigation tree.

Perform create and read point operations on items with the SDK

You will now use the set of methods in the ContainerProxy class to perform common operations on items within a NoSQL API container.

Return to Visual Studio Code. If it is not still open, open the script.py code file within the python/03-sdk-crud folder.

Create a new product item and assign it to a variable named saddle with the following properties:

Property	Value
id	706cd7c6-db8b-41f9-aea2-0e0c7e8eb009
categoryId	9603ca6c-9e28-4a02-9194-51cdb7fea816
name	Road Saddle
price	45.99d
tags	{ tan, new, crisp }

saddle = {
    "id": "706cd7c6-db8b-41f9-aea2-0e0c7e8eb009",
    "categoryId": "9603ca6c-9e28-4a02-9194-51cdb7fea816",
    "name": "Road Saddle",
    "price": 45.99,
    "tags": ["tan", "new", "crisp"]
}

Invoke the create_item method of the container variable passing in the saddle variable as the method parameter:
```
await container.create_item(body=saddle)
```

Once you are done, your code file should now include:

from azure.cosmos import PartitionKey
from azure.cosmos.aio import CosmosClient
from azure.identity.aio import DefaultAzureCredential
import asyncio

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

async def main():
    async with CosmosClient(endpoint, credential=credential) as client:
        # Create database
        database = await client.create_database_if_not_exists(id="cosmicworks")
    
        # Create container
        container = await database.create_container_if_not_exists(
            id="products",
            partition_key=PartitionKey(path="/categoryId")
        )
        
        saddle = {
            "id": "706cd7c6-db8b-41f9-aea2-0e0c7e8eb009",
            "categoryId": "9603ca6c-9e28-4a02-9194-51cdb7fea816",
            "name": "Road Saddle",
            "price": 45.99,
            "tags": ["tan", "new", "crisp"]
        }
            
        await container.create_item(body=saddle)

if __name__ == "__main__":
    asyncio.run(main())

Save and run the script again:
```
python script.py
```
Observe the new item in the Data Explorer.
Return to Visual Studio Code.
Return to the editor tab for the script.py code file.

Delete the following lines of code:

saddle = {
    "id": "706cd7c6-db8b-41f9-aea2-0e0c7e8eb009",
    "categoryId": "9603ca6c-9e28-4a02-9194-51cdb7fea816",
    "name": "Road Saddle",
    "price": 45.99,
    "tags": ["tan", "new", "crisp"]
}
    
await container.create_item(body=saddle)

Create a string variable named item_id with a value of 706cd7c6-db8b-41f9-aea2-0e0c7e8eb009:
```
item_id = "706cd7c6-db8b-41f9-aea2-0e0c7e8eb009"
```
Create a string variable named partition_key with a value of 9603ca6c-9e28-4a02-9194-51cdb7fea816:
```
partition_key = "9603ca6c-9e28-4a02-9194-51cdb7fea816"
```
Invoke the read_item method of the container variable passing in the item_id and partition_key variables as the method parameters:
```
# Read item    
saddle = await container.read_item(item=item_id, partition_key=partition_key)
```
💡 The read_item method allows you to perform a point read operation on an item in the container. The method requires the item_id and partition_key parameters to identify the item to read. As opposed to executing a query using Cosmos DB’s SQL query language to find the single item, the read_item method is more efficient and cost-effective way to retrieve a single item. Point reads can read the data directly and don’t require the query engine to process the request.

Print the saddle object using a formatted output string:

print(f'[{saddle["id"]}]\t{saddle["name"]} ({saddle["price"]})')

Once you are done, your code file should now include:

from azure.cosmos import PartitionKey
from azure.cosmos.aio import CosmosClient
from azure.identity.aio import DefaultAzureCredential
import asyncio

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

async def main():
    async with CosmosClient(endpoint, credential=credential) as client:
        # Create database
        database = await client.create_database_if_not_exists(id="cosmicworks")
    
        # Create container
        container = await database.create_container_if_not_exists(
            id="products",
            partition_key=PartitionKey(path="/categoryId")
        )
       
        item_id = "706cd7c6-db8b-41f9-aea2-0e0c7e8eb009"
        partition_key = "9603ca6c-9e28-4a02-9194-51cdb7fea816"
   
        # Read item
        saddle = await container.read_item(item=item_id, partition_key=partition_key)
            
        print(f'[{saddle["id"]}]\t{saddle["name"]} ({saddle["price"]})')

if __name__ == "__main__":
    asyncio.run(main())

Save and run the script again:
```
python script.py
```
Observe the output from the terminal. Specifically, observe the formatted output text with the id, name, and price from the item.

Perform update and delete point operations with the SDK

While learning the SDK, it’s not uncommon to use an online Azure Cosmos DB account or the emulator to update an item and oscillate back-and-forth between the Data Explorer and your IDE of choice as you perform an operation and check to see if your change has been applied. Here, you will do just that as you update and delete an item using the SDK.

Return to your web browser window or tab.
Within the Azure Cosmos DB account resource, navigate to the Data Explorer pane.
In the Data Explorer, expand the cosmicworks database node, then expand the new products container node within the NOSQL API navigation tree.
Select the Items node. Select the only item within the container and then observe the values of the name and price properties of the item.

Property Value

Name Road Saddle

Price $45.99

📝 At this point in time, these values should not have been changed since you have created the item. You will change these values in this exercise.
Return to Visual Studio Code. Return to the editor tab for the script.py code file.

Property	Value
Name	Road Saddle
Price	$45.99

Delete the following line of code:

print(f'[{saddle["id"]}]\t{saddle["name"]} ({saddle["price"]})')

Change the saddle variable by setting the value of the price property to 32.55:
```
saddle["price"] = 32.55
```
Modify the saddle variable again by setting the value of the name property to Road LL Saddle:
```
saddle["name"] = "Road LL Saddle"
```
Invoke the replace_item method of the container variable passing in the item_id and saddle variables as method parameters:
```
await container.replace_item(item=item_id, body=saddle)
```

Once you are done, your code file should now include:

from azure.cosmos import PartitionKey
from azure.cosmos.aio import CosmosClient
from azure.identity.aio import DefaultAzureCredential
import asyncio

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

async def main():
    async with CosmosClient(endpoint, credential=credential) as client:
        # Create database
        database = await client.create_database_if_not_exists(id="cosmicworks")
    
        # Create container
        container = await database.create_container_if_not_exists(
            id="products",
            partition_key=PartitionKey(path="/categoryId")
        )
        
        item_id = "706cd7c6-db8b-41f9-aea2-0e0c7e8eb009"
        partition_key = "9603ca6c-9e28-4a02-9194-51cdb7fea816"
    
        # Read item
        saddle = await container.read_item(item=item_id, partition_key=partition_key)
            
        saddle["price"] = 32.55
        saddle["name"] = "Road LL Saddle"
    
        await container.replace_item(item=item_id, body=saddle)

if __name__ == "__main__":
    asyncio.run(main())

Save and run the script again:
```
python script.py
```
Return to your web browser window or tab.
Within the Azure Cosmos DB account resource, navigate to the Data Explorer pane.
In the Data Explorer, expand the cosmicworks database node, then expand the new products container node within the NOSQL API navigation tree.
Select the Items node. Select the only item within the container and then observe the values of the name and price properties of the item.

Property Value

Name Road LL Saddle

Price $32.55

📝 At this point in time, these values should have been changed since you have observed the item.
Return to Visual Studio Code. Return to the editor tab for the script.py code file.

Property	Value
Name	Road LL Saddle
Price	$32.55

Delete the following lines of code:

# Read item
saddle = await container.read_item(item=item_id, partition_key=partition_key)
    
saddle["price"] = 32.55
saddle["name"] = "Road LL Saddle"
    
await container.replace_item(item=item_id, body=saddle)

Invoke the delete_item method of the container variable passing in the item_id and partition_key variables as method parameters:
```
# Delete the item
await container.delete_item(item=item_id, partition_key=partition_key)
```
Save and run the script again:
```
python script.py
```
Close the integrated terminal.
Return to your web browser window or tab.
Within the Azure Cosmos DB account resource, navigate to the Data Explorer pane.
In the Data Explorer, expand the cosmicworks database node, then expand the new products container node within the NOSQL API navigation tree.
Select the Items node. Observe that the items list is now empty.
Close your web browser window or tab.
Close Visual Studio Code.