In this guide, we will discuss the common issue of being unable to import the module lambda_function when working with AWS Lambda. We will provide a step-by-step solution to resolve the "No Module Named 'lambda_function'" error and answer frequently asked questions related to this issue.
Table of Contents
Understanding the Issue
When working with AWS Lambda functions in Python, you might encounter the following error message:
{
"errorMessage": "Unable to import module 'lambda_function': No module named 'lambda_function'",
"errorType": "Runtime.ImportModuleError"
}
This error occurs when AWS Lambda is unable to locate the lambda_function module in your deployment package or the handler is not correctly defined.
Understanding AWS Lambda Error Messages
Step-by-Step Solution
To resolve the "No Module Named 'lambda_function'" error, follow these steps:
Step 1: Check Your Deployment Package Structure
Ensure that the deployment package structure is correct. The lambda_function.py file should be located at the root level of the deployment package.
my-deployment-package/
│
├── lambda_function.py
├── other_module.py
└── requirements.txt
Step 2: Review Your Lambda Handler
Check your Lambda function's handler in the AWS Management Console. The handler should be in the format filename.handler_function_name. For example, if your lambda_function.py file has a function named my_handler, the handler should be set to lambda_function.my_handler.
AWS Lambda Function Handler in Python
Step 3: Re-Upload Your Deployment Package
After verifying the deployment package structure and Lambda handler, create a new deployment package and upload it to AWS Lambda.
Creating a Deployment Package (Python)
Step 4: Test Your Lambda Function
Once the new deployment package is uploaded, test your Lambda function to see if the error has been resolved.
FAQ
1. How do I create a deployment package for my Lambda function?
To create a deployment package for your Lambda function, follow the instructions in the Creating a Deployment Package (Python) guide.
2. Can I use a different file name instead of lambda_function.py?
Yes, you can use any file name for your Lambda function. Just make sure to update the handler in the AWS Management Console to match your file name and handler function name.
3. How do I include third-party libraries in my deployment package?
To include third-party libraries in your deployment package, use the pip command to install the libraries in a folder named package. Then, add your Lambda function code to the package folder and create a ZIP archive of the folder. For more information, follow the instructions in the Creating a Deployment Package (Python) guide.
4. Why am I still getting the "No Module Named 'lambda_function'" error after following these steps?
If the error persists, double-check your deployment package structure, handler settings in the AWS Management Console, and ensure your deployment package does not exceed the maximum unzipped file size of 250 MB. If the issue remains unresolved, check the AWS Lambda Developer Guide and AWS Lambda Forums for additional resources.
5. How do I monitor and troubleshoot my Lambda function?
You can use Amazon CloudWatch Logs and AWS X-Ray to monitor, troubleshoot, and optimize your Lambda function. For more information, refer to the Monitoring and Troubleshooting in AWS Lambda guide.