"errorMessage": "Unable to import module 'lambda_function'

Question

Upon testing my lambda function I get the following error message:

{
  "errorMessage": "Unable to import module 'lambda_function'"
}

I uploaded a .zip which only includes the following dependancies: requests, boto3, PIL, Pillow-4.0.0.dist-info & the lambda function lambda_function.py - which is a copied example from AWS:

from __future__ import print_function
import boto3
import os
import sys
import uuid
from PIL import Image
import PIL.Image

s3_client = boto3.client('s3')

def resize_image(image_path, resized_path):
    with Image.open(image_path) as image:
        image.thumbnail(tuple(x / 2 for x in image.size))
        image.save(resized_path)

def handler(event, context):
    for record in event['Records']:
        bucket = record['s3']['bucket']['name']
        key = record['s3']['object']['key'] 
        download_path = '/tmp/{}{}'.format(uuid.uuid4(), key)
        upload_path = '/tmp/resized-{}'.format(key)

        s3_client.download_file(bucket, key, download_path)
        resize_image(download_path, upload_path)
        s3_client.upload_file(upload_path, '{}resized'.format(bucket), key)

My handler is: lambda_function.lambda_handler

Any idea what the problem is?

How are you testing it? Where are you trying to run it? Using AWS Lambda Console? — NoorJafri, Jun 12 '18 at 09:46
lambda_function.lambda_handler or lambda_function.handler? but that doesn't matter if you are running from the console. Let me see — NoorJafri, Jun 12 '18 at 09:53
i see the function name is present as handler, by default, lambda accepts as lambda_handler, can you change it and zip then try ? — Gowtham Chand, Jun 12 '18 at 09:57
The handler is `lambda_function.lambda_handler` @NoorAliJafri — Zorgan, Jun 12 '18 at 10:14
Change the file name `lambda_function.py` to `lambda_handler.py`? @GowthamChand — Zorgan, Jun 12 '18 at 10:15
@Zorgan change the handler name to `lambda_function.handler` or update your code to `def lambda_handler(event, context):` then zip it and upload. — Vaisakh PS, Jun 12 '18 at 11:07

NoorJafri · Accepted Answer · 2018-06-12T12:08:05.267

2

Firstly:

By default lambda runs the handler with the specific keyword named: lambda_handler you can change the handler entry as well in the AWS Lambda console.

Or you have to change the name of your handler:

def handler(event, context):
    for record in event['Records']:
    ,,,

def lambda_handler(event,context):  
    '''

You can use custom handler while working with some framework and explicitly mention the handler name.

For example with serverless:

your_action:
    handler: path/lambda_function.handler

Secondly:

part of the issue is that you have to check for the modules you have been importing are included. You have to see a detailed error output for that. The immediate response for your scenario would be: unable to import lambda_function.

Checking error log you might see something like this: Unable to import module 'lambda_function': No module named PIL

You also must checkout this question here regarding importing PIL

edited Jun 12 '18 at 12:08

answered Jun 12 '18 at 10:16

NoorJafri

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1

I changed the handler entry in the AWS Lambda console to `lambda_function.handler` and I'm still getting the same error. Any idea why? – Zorgan Jun 12 '18 at 11:18
Press SAVE and then run it – NoorJafri Jun 12 '18 at 11:19
*from PIL import Image import PIL.Image* removing these two lines work. Now comes to the second part of the problem. – NoorJafri Jun 12 '18 at 11:26
Check if you have included the module. – NoorJafri Jun 12 '18 at 11:29
Worked for you? – NoorJafri Jun 12 '18 at 11:47
I've removed `from PIL import Image import PIL.Image`, re-uploaded, saved, then tested but still getting the same error...not sure why. What do you mean by "Check if you have included the module"? – Zorgan Jun 12 '18 at 12:03
Editing the post. – NoorJafri Jun 12 '18 at 12:07
Ah yes you're right, the detailed error says: `Unable to import module 'lambda_function': cannot import name '_imaging'` - however there's no use of `_imaging` in the function. – Zorgan Jun 12 '18 at 12:22
I haven't worked with this PIL, so can't tell you more than that. – NoorJafri Jun 12 '18 at 12:23
Should be easier to fix from here with detailed log - thanks for the help! – Zorgan Jun 12 '18 at 12:31

"errorMessage": "Unable to import module 'lambda_function'

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