How to create an Azure durable function in Python?

How to create an Azure durable function in Python?

To create an Azure Durable Function in Python, you'll need to follow these steps:

Step 1: Create a new Azure Functions project

Open your preferred IDE (Integrated Development Environment) and create a new project using the Azure Functions template. You can choose either the "Azure Functions" or "Azure Functions with Python" option.

Step 2: Install required packages

In your project directory, run the following command to install the necessary packages:

pip install azure-functions-python-proto
azure-functions-vscode

The first package is required for building and running Durable Functions, while the second package provides Visual Studio Code (VS Code) integration.

Step 3: Define your Python function

Create a new file named main.py in your project directory. This file will contain the definition of your Azure Durable Function.

For example, let's create a simple "Hello World" function that uses the Durable Functions framework:

import azure.functions as func
def hello_world(name: str) -> str:
return f"Hello, {name}!"

This is just a regular Python function that takes a name parameter and returns a greeting message.

Step 4: Create a Durable Function

To turn your regular Python function into a Durable Function, you'll need to create an instance of the DurableFunctionConfig class and pass it as an argument to your function. Here's how you can do it:

import azure.functions as func
def hello_world(name: str) -> str:
df = func.DurableFunctionConfig(
name="HelloWorld",
bindings={
"timer": {
"schedule": "0 */5 * * * *"  # runs every 5 minutes
}
}
)
return f"Hello, {name}!"

In this example, we're creating a Durable Function named "HelloWorld" that has a timer binding that triggers the function every 5 minutes.

Step 5: Create an orchestration function

An orchestration function is responsible for coordinating the execution of multiple Durable Functions. To create one, you can use the following code:

import azure.functions as func
def orchestrator(ctx):
name = ctx.bindings.get("name")
if not name:
raise ValueError("Name is required")
Call the "HelloWorld" function and get its output
hello_world_output = ctx.call_activity(
"HelloWorld",
{"name": name}
)
Return the result
return hello_world_output

This orchestration function takes a name parameter from the timer binding, calls the hello_world function with that name, and returns its output.

Step 6: Deploy your Azure Durable Function

Once you've created and tested your Durable Function, you can deploy it to Azure. You'll need to create an Azure Storage account and a Service Bus namespace. Then, use the func azure deployment group command to deploy your function to Azure.

That's it! With these steps, you should now have a working Azure Durable Function written in Python.

Azure function python environment variable

I'll respond in English as per your request. Here's the information on using Python with Azure Functions and working with environment variables:

When you create an Azure Function using Python, you can set environment variables to configure your application. Environment variables are key-value pairs that are stored outside of your code, which makes it easier to manage configurations without modifying your code.

To use environment variables in a Python-based Azure Function, you need to follow these steps:

import os
def main(my_var):
my_value = os.environ.get('MY_VAR')
print(f"My Value: {my_value}")

In this example, os.environ.get('MY_VAR') retrieves the value of the environment variable named MY_VAR. You can then use this value in your code.

func host start -e MY_VAR="hello world"

This command sets the MY_VAR environment variable to "hello world" while running your function locally.

Benefits of Using Environment Variables:

Azure Functions Python Environment Variables Example:

Here's an example of how you can use environment variables in your Azure Function written in Python:

import os
def main(my_var):
my_value = os.environ.get('MY_VAR')
if my_value == 'hello':
print("Hello world!")
else:
print(f"Hello, {my_value}!")

In this example, the os.environ.get('MY_VAR') line retrieves the value of the environment variable MY_VAR. The function then uses this value to print out a message.