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Create a Python function from the command line - Azure Functions
Learn how to create a Python function from the command line, then publish the local project to serverless hosting in Azure Functions.
02/29/2024
quickstart
python
devx-track-python, devx-track-azurecli, devx-track-azurepowershell, mode-api, devdivchpfy22

Quickstart: Create a Python function in Azure from the command line

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.

There's also a Visual Studio Code-based version of this article.

Configure your local environment

Before you begin, you must have the following requirements in place:

[!INCLUDE functions-install-core-tools]

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.

bash

python -m venv .venv
source .venv/bin/activate

If Python didn't install the venv package on your Linux distribution, run the following command:

sudo apt-get install python3-venv

PowerShell

py -m venv .venv
.venv\scripts\activate

Cmd

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.

  1. 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.

  2. 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.

[!INCLUDE functions-run-function-test-local-cli]

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.

  1. If needed, sign in to Azure.

    Azure CLI

    az login

    The az login command signs you into your Azure account.

    Azure PowerShell

    Connect-AzAccount

    The Connect-AzAccount cmdlet signs you into your Azure account.

  2. Create a resource group named AzureFunctionsQuickstart-rg in your chosen region.

    Azure CLI

    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.

    Azure PowerShell

    New-AzResourceGroup -Name AzureFunctionsQuickstart-rg -Location '<REGION>'

    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.

  3. Create a general-purpose storage account in your resource group and region.

    Azure CLI

    az storage account create --name <STORAGE_NAME> --location <REGION> --resource-group AzureFunctionsQuickstart-rg --sku Standard_LRS

    The az storage account create command creates the storage account.

    Azure PowerShell

    New-AzStorageAccount -ResourceGroupName AzureFunctionsQuickstart-rg -Name <STORAGE_NAME> -SkuName Standard_LRS -Location <REGION>

    The New-AzStorageAccount cmdlet creates the storage account.

    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.

  4. Create the function app in Azure.

    Azure CLI

    az functionapp create --resource-group AzureFunctionsQuickstart-rg --consumption-plan-location westeurope --runtime python --runtime-version <PYTHON_VERSION> --functions-version 4 --name <APP_NAME> --os-type linux --storage-account <STORAGE_NAME>

    The az functionapp create command creates the function app in Azure. You must supply --os-type linux because Python functions only run on Linux.

    Azure PowerShell

    New-AzFunctionApp -Name <APP_NAME> -ResourceGroupName AzureFunctionsQuickstart-rg -StorageAccountName <STORAGE_NAME> -FunctionsVersion 4 -RuntimeVersion <PYTHON_VERSION> -Runtime python -Location '<REGION>'

    The New-AzFunctionApp cmdlet creates the function app in Azure.

    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.

[!INCLUDE functions-publish-project-cli]

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.

Browser

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.

curl

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."

[!INCLUDE functions-cleanup-resources-cli]

Next steps

[!div class="nextstepaction"] Connect to Azure Cosmos DB [!div class="nextstepaction"] Connect to an Azure Storage queue

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