Formatting DynamoDB data to normal JSON in AWS Lambda

Question

I\'m using AWS Lambda to scan data from a DynamoDB table. This is what I get in return:

{
  \"videos\": [
    {
      \"fil         


        

Answer 1

• Javascript: AWS SDK provides the unmarshall function

• Python: use TypeDeserializer from boto3.dynamodb.types:

from boto3.dynamodb.types import TypeDeserializer, TypeSerializer

def from_dynamodb_to_json(item):
    d = TypeDeserializer()
    return {k: d.deserialize(value=v) for k, v in item.items()}

## Usage:
from_dynamodb_to_json({
    "Day": {"S": "Monday"},
    "mylist": {"L": [{"S": "Cookies"}, {"S": "Coffee"}, {"N": "3.14159"}]}
})
# {'Day': 'Monday', 'mylist': ['Cookies', 'Coffee', Decimal('3.14159')]}

Answer 2

If you are using python in the lambda you can utilise the dynamodb-json library.

Install library

pip install dynamodb-json

and use the below snippet

from dynamodb_json import json_util as util

def marshall(regular_json):
    dynamodb_json = util.dumps(reular_json)

def unmarshall(dynamodb_json):
    regular_json = util.loads(dynamodb_json)

Reference https://pypi.org/project/dynamodb-json/