AWS Lambda Python S3 Read File Error

Question

Trying to read a file from a bucket in s3. The bucket has a trigger wired to a python lambda function. This then runs when a new file is put in the bucket. I keep getting an error.

This the code:

Download the file from S3 to the local filesystem

try:
    s3.meta.client.download_file(bucket, key, localFilename)
except Exception as e:
    print(e)
    print('Error getting object {} from bucket {}. Make sure they exist and your bucket is in the same region as this function.'.format(key, bucket))
    raise e

I get this error

'ClientMeta' object has no attribute 'client'

I am thinking it could be the IAM but the Lambda function has the AWSLambdaFullAccess Role which is pretty much an admin in S3.

Any help would be much appreciated

Answer 1

This error is caused by creating a boto3 client instead of resource .

Example (this will reproduce your error):

s3 = boto3.client('s3')
s3.meta.client.download_file(bucket, key, localFilename)

You have two solutions:

1) Change to use the " high-level abstracted " s3 resource:

s3 = boto3.resource('s3')
s3.meta.client.download_file(bucket, key, localFilename)

2) Directly use the " low-level " s3 client download_file()

s3 = boto3.client('s3')
s3.download_file(bucket, key, localFilename)

Working with Boto3 Low-Level Clients

Answer 2

I think may be refer incorrectly object type for variable s3 . s3.meta.client may be something you use when s3 is ResourceMeta object, but here I think s3 is Client object.

So you can just write

try: s3.download_file(bucket, key, localFilename) except Exception as e: ...