Boto3: DynamoDB batch_get_item returns only DynamoJSON

[tomtalp]

Hey,
When using the DynamoDB get_item function, an item is returned perfectly fine in a JSON format.
However, when using the batch_get_item function -

 s = client.batch_get_item(
    RequestItems={
    'my_table':
        {'Keys':
            [
                {'key':
                    {'S':'val1'}
                }, 
                {'key':
                    {'S':'val2'}
                }
            ]
        }
    })

The response is returned as DynamoDB JSON -

 u'Responses': 
    {u'my_table': 
        [
            {u'key': {u'S': u'0.0'},
            u'key2': {u'S': u'value'},
        ]
    }

Is there a way to deal with this?
I couldn't find a way to parse responses like this in the boto docs, and when going through the code I see that responses for get_item are indeed parsed (transform.py), but nothing happens for batch_get_item

What's the solution? There has to be a better way than writing a parser from scrath...
Thanks!

[kyleknap]

I would just create a resource and then just drop down to the client. So something like this:

import boto3

dynamodb = boto3.resource('dynamodb')
 s = dynamodb.meta.client.batch_get_item(
    RequestItems={
    'my_table':
        {'Keys':
            [
                {'key':'val1'}, 
                {'key':'val2'}
            ]
        }
    })

That should get it to you in non DynamoDB JSON format. Let us know if you have anymore questions.

[kyleknap]

Closing issue. Let us know if you have any follow up questions.

[siddhaa]

Hey @kyleknap

i used the above to read in batches, however it throws the following error

botocore.exceptions.ClientError: An error occurred (ValidationException) when calling the BatchGetItem operation: The provided key element does not match the schema

Table :
Primary partition key
queue (String)
Primary sort key
diff (Number)

code : response = table.meta.client.batch_get_item(
RequestItems = {
"TASK_SUMMARY":{
"Keys": [
{'queue':'UK_FRAUD'},
{'diff':10} ] }
},
)

Questions:
1) Where am i going wrong?
2) how can i pass multiple values for queues and diff

[lucasrcosta]

@kyleknap I have the same query working on client.batch_get_item returning the Dynamo JSON and on dynamodb.meta.client.batch_get_item returning empty results. Are you sure this is the right way on Boto3?

In the meantime, this helped: http://stackoverflow.com/questions/37872542/is-there-a-python-api-for-submitting-batch-get-requests-to-aws-dynamodb
boto3.dynamodb.types.TypeDeserializer