How can I run python script manually in AWS Lambda?

Step 1: Prerequisites

Before you begin, ensure you have the following:

1. An AWS account.
2. AWS CLI installed and configured with appropriate permissions.
3. Basic knowledge of Python programming.

Step 2: Create the Python Script

Write the Python script that you want to execute in the Lambda function. For example:

# lambda_function.py

def lambda_handler(event, context):
    """
    This is the entry point for the AWS Lambda function.
    :param event: Input data passed to the function.
    :param context: Runtime information provided by AWS Lambda.
    :return: A response object.
    """
    # Example logic
    message = "Hello from Lambda!"
    return {
        "statusCode": 200,
        "body": message
    }

Save this file as lambda_function.py. This script defines a function lambda_handler, which is the entry point for AWS Lambda.

Step 3: Package the Python Script

AWS Lambda requires your code to be packaged in a specific way. For simple scripts like the one above, you can directly upload the .py file. However, if your script has dependencies, you need to create a deployment package.

1. For Simple Scripts :

   • No additional steps are needed. Proceed to Step 4.

2. For Scripts with Dependencies :

   • Install dependencies in a local directory:

mkdir python
pip install  -t python/

Step 4: Create the Lambda Function

1. Log in to the AWS Management Console.
2. Navigate to the Lambda service.
3. Click Create Function .
4. Choose Author from scratch .
5. Provide the following details:
   • Function Name : e.g., MyPythonLambda
   • Runtime : Select Python 3.x (e.g., Python 3.9).
   • Permissions : Use an existing role or create a new one with basic Lambda execution permissions.
6. Click Create Function .

Step 5: Upload the Code

1. In the Lambda function dashboard, scroll to the Code section.
2. If you are uploading a single .py file:
   • Select Upload from > .zip file .
   • Upload your lambda_function.py file.
3. If you are using a deployment package:
   • Select Upload from > .zip file .
   • Upload your lambda_package.zip.

Step 6: Configure the Handler

1. In the Runtime settings , ensure the handler is set correctly.
   • For lambda_function.py, the handler should be lambda_function.lambda_handler.
   • The format is ..

To run a Python script in an AWS Lambda function, you need to configure your Lambda function to use the Python runtime environment and follow a specific structure for your function code. I'll provide you with a step-by-step tutorial on how to achieve this:

Step 1: Create a New Lambda Function

1. Go to the AWS Management Console and navigate to the Lambda service.

2. Click on "Create function" to start creating a new Lambda function.

3. Choose "Author from scratch" as the starting point.

4. Enter the basic details for your function, such as a name, runtime (select Python), and choose the appropriate permissions.

Step 2: Write Your Python Script

1. In the function code section, you can directly write your Python script or upload a ZIP file containing your script. Remember, your script should have a handler function that Lambda can call.

   def my_handler(event, context):
       # Your Python script logic here
       return {
           'statusCode': 200,
           'body': 'Hello from Lambda!'
       }

 

Step 3: Configure the Lambda Function

1. Set the handler to point to your function in the format `filename.handler_function_name`. For example, if your script file is `my_script.py` and the handler function is `my_handler`, your handler should be `my_script.my_handler`.

2. You can set up environment variables, memory, timeout, and other settings based on your requirements.

3. Make sure to save your function after making any changes.

Step 4: Test Your Lambda Function

1. You can test your Lambda function within the AWS Management Console by configuring a test event.

2. Click on the "Test" button to run your function and view the results in the console.

Step 5: Invoke Your Lambda Function

1. You can trigger your Lambda function manually from the AWS Management Console or set up triggers such as API Gateway, S3 events, etc., based on your use case.

2. Monitor the execution of your function through CloudWatch logs for debugging and tracking.

By following these steps, you can create and run a Python script in an AWS Lambda function seamlessly. Don't forget to test your function thoroughly and adjust configurations as needed for optimal performance. Let me know if you need further clarification or assistance!

Check out this step by step tutorial: 

Run Your First Python Script in AWS Lambda