Quickstart: Create a Python function in Azure from the command line
Article
03/05/2024
In this article, you use command-line tools to create a Python function that responds to HTTP requests. After testing the code locally, you deploy it to the serverless environment of Azure Functions.
This article uses the Python v2 programming model for Azure Functions, which provides a decorator-based approach for creating functions. To learn more about the Python v2 programming model, see the Developer Reference Guide
Completing this quickstart incurs a small cost of a few USD cents or less in your Azure account.
The following steps use a Windows installer (MSI) to install Core Tools v4.x. For more information about other package-based installers, see the Core Tools readme.
Download and run the Core Tools installer, based on your version of Windows:
If you previously used Windows installer (MSI) to install Core Tools on Windows, you should uninstall the old version from Add Remove Programs before installing the latest version.
The following steps use Homebrew to install the Core Tools on macOS.
brew tap azure/functions
brew install azure-functions-core-tools@4
# if upgrading on a machine that has 2.x or 3.x installed:
brew link --overwrite azure-functions-core-tools@4
The following steps use APT to install Core Tools on your Ubuntu/Debian Linux distribution. For other Linux distributions, see the Core Tools readme.
Install the Microsoft package repository GPG key, to validate package integrity:
Check the /etc/apt/sources.list.d/dotnetdev.list file for one of the appropriate Linux version strings in the following table:
Linux distribution
Version
Debian 12
bookworm
Debian 11
bullseye
Debian 10
buster
Debian 9
stretch
Ubuntu 24.04
noble
Ubuntu 22.04
jammy
Ubuntu 20.04
focal
Ubuntu 19.04
disco
Ubuntu 18.10
cosmic
Ubuntu 18.04
bionic
Ubuntu 17.04
zesty
Ubuntu 16.04/Linux Mint 18
xenial
Start the APT source update:
sudo apt-get update
Install the Core Tools package:
sudo apt-get install azure-functions-core-tools-4
Use the func --version command to make sure your version of Core Tools is at least 4.0.5530.
Create and activate a virtual environment
In a suitable folder, run the following commands to create and activate a virtual environment named .venv. Make sure that you're using a version of Python supported by Azure Functions.
If Python didn't install the venv package on your Linux distribution, run the following command:
sudo apt-get install python3-venv
py -m venv .venv
.venv\scripts\activate
py -m venv .venv
.venv\scripts\activate
You run all subsequent commands in this activated virtual environment.
Create a local function
In Azure Functions, a function project is a container for one or more individual functions that each responds to a specific trigger. All functions in a project share the same local and hosting configurations.
In this section, you create a function project and add an HTTP triggered function.
Run the func init command as follows to create a Python v2 functions project in the virtual environment.
func init --python
The environment now contains various files for the project, including configuration files named local.settings.json and host.json. Because local.settings.json can contain secrets downloaded from Azure, the file is excluded from source control by default in the .gitignore file.
Add a function to your project by using the following command, where the --name argument is the unique name of your function (HttpExample) and the --template argument specifies the function's trigger (HTTP).
func new --name HttpExample --template "HTTP trigger" --authlevel "anonymous"
If prompted, choose the ANONYMOUS option. func new adds an HTTP trigger endpoint named HttpExample to the function_app.py file, which is accessible without authentication.
Run the function locally
Run your function by starting the local Azure Functions runtime host from the LocalFunctionProj folder.
func start
Toward the end of the output, the following lines must appear:
Note
If HttpExample doesn't appear as shown above, you likely started the host from outside the root folder of the project. In that case, use Ctrl+C to stop the host, go to the project's root folder, and run the previous command again.
Copy the URL of your HTTP function from this output to a browser and append the query string ?name=<YOUR_NAME>, making the full URL like http://localhost:7071/api/HttpExample?name=Functions. The browser should display a response message that echoes back your query string value. The terminal in which you started your project also shows log output as you make requests.
When you're done, press Ctrl + C and type y to stop the functions host.
Create supporting Azure resources for your function
Before you can deploy your function code to Azure, you need to create three resources:
A resource group, which is a logical container for related resources.
A storage account, which maintains the state and other information about your projects.
A function app, which provides the environment for executing your function code. A function app maps to your local function project and lets you group functions as a logical unit for easier management, deployment, and sharing of resources.
Use the following commands to create these items. Both Azure CLI and PowerShell are supported.
az group create --name AzureFunctionsQuickstart-rg --location <REGION>
The az group create command creates a resource group. In the above command, replace <REGION> with a region near you, using an available region code returned from the az account list-locations command.
The New-AzResourceGroup command creates a resource group. You generally create your resource group and resources in a region near you, using an available region returned from the Get-AzLocation cmdlet.
Note
You can't host Linux and Windows apps in the same resource group. If you have an existing resource group named AzureFunctionsQuickstart-rg with a Windows function app or web app, you must use a different resource group.
Create a general-purpose storage account in your resource group and region.
In the previous example, replace <STORAGE_NAME> with a name that's appropriate to you and unique in Azure Storage. Names must contain 3 to 24 characters numbers and lowercase letters only. Standard_LRS specifies a general-purpose account supported by Functions.
The storage account incurs only a few cents (USD) for this quickstart.
In the previous example, replace <APP_NAME> with a globally unique name appropriate to you. The <APP_NAME> is also the default subdomain for the function app. Make sure that the value you set for <PYTHON_VERSION> is a version supported by Functions and is the same version you used during local development.
This command creates a function app running in your specified language runtime under the Azure Functions Consumption Plan, which is free for the amount of usage you incur here. The command also creates an associated Azure Application Insights instance in the same resource group, with which you can monitor your function app and view logs. For more information, see Monitor Azure Functions. The instance incurs no costs until you activate it.
Deploy the function project to Azure
After you've successfully created your function app in Azure, you're now ready to deploy your local functions project by using the func azure functionapp publish command.
In this example, replace <APP_NAME> with the name of your app. A successful deployment shows results similar to the following output (truncated for simplicity):
...
Getting site publishing info...
Creating archive for current directory...
Performing remote build for functions project.
...
Deployment successful.
Remote build succeeded!
Syncing triggers...
Functions in msdocs-azurefunctions-qs:
HttpExample - [httpTrigger]
Invoke url: https://msdocs-azurefunctions-qs.azurewebsites.net/api/httpexample
Invoke the function on Azure
Because your function uses an HTTP trigger, you invoke it by making an HTTP request to its URL in the browser or with a tool like curl.
Copy the complete Invoke URL shown in the output of the publish command into a browser address bar, appending the query parameter ?name=Functions. The browser should display similar output as when you ran the function locally.
Run curl with the Invoke URL shown in the output of the publish command, appending the parameter ?name=Functions. The output of the command should be the text, "Hello Functions."
Clean up resources
If you continue to the next step and add an Azure Storage queue output binding, keep all your resources in place as you'll build on what you've already done.
Otherwise, use the following command to delete the resource group and all its contained resources to avoid incurring further costs.
In this learning path, discover Azure Functions that create event-driven, compute-on-demand systems using server-side logic to build serverless architectures.
Build end-to-end solutions in Microsoft Azure to create Azure Functions, implement and manage web apps, develop solutions utilizing Azure storage, and more.