What you are printing is a python dict, it looks sort of like JSON but is not JSON, it is the representation of a python dict. That means it will have True / False instead of true / false, it will have ' instead of ", etc.

You could do print(json.dumps(event)) instead.

Anyway, the actual problem is that invokingEvent is yet another JSON, but in its string form, you need to to json.loads that nested JSON string. You can see that because the value after invokingEvent is inside another set of '...', therefore it is a string, not a parsed dict already.

invoking_event = json.loads(event['invokingEvent'])
change_type = invoking_event["configurationItemDiff"]["changeType"]

ruleParameters would be another nested JSON which needs parsing first if you wanted to use it.

Probably Postman believes that the output is plain text. Try to set "Content-Type" header to "application/json".

Try

import json

def lambda_handler(event, context):
    body = json.loads(event['body'])
    return {
        'statusCode': 200,
        'body': json.dumps(body['data'])
    }

In your lambda function you should return a response object with a JSON object in the response body.

# Lambda Function
def get_json(event, context):
    """Retrieve JSON from server."""
    # Business Logic Goes Here.
    response = {
        "statusCode": 200,
        "headers": {},
        "body": json.dumps({
            "message": "This is the message in a JSON object."
        })
    }
    return response

You have to use json.loads not json.dumps.

Try this:

import json

event = {
   "Records":[
      {
         "messageId":"916f5e95-b2f6-4148-9c62-2ac8e764f06c",
         "receiptHandle":"AQEBmLuoGWtLtFFgvyCFdSPMJh2HKgHOIPWNUq22EOwCzGT8iILZm97CE6j4J6oR71ZpDr3sgxQcJyVZ+dmmvGl+fFftT9GCJqZYrjMGsR2Q6WsMd8ciI8bTtDXyvsk8ektd7UGfh4gxIZoFp7WUKVRcMEeBkubKd8T4/Io81D0l/AK7MxcEfCj40vWEsex1kkGmMRlBtdSeGyy7fJgUq5CFAYWciiWtbSit8S0Y38xZPmsIFhoxP0egQRoJcW4aUgMi469Gj5+khizetybtgC8vux5NCg/IejxcCueXkQ7LKVF8kfRdqRSUYB6DsOrGgfmZpK4wpXIarByNz0R2p7J88meYpj2IVULv/emXsSYaKG4rXnpbH4J9ijbLWckYLAd7wPDzCYri1ZSTgAz0kchsEw==",
         "body":"{\n\"name\": \"aniket\",\n\"tag\": \"hello\"\n}",
         "attributes":{
            "ApproximateReceiveCount":"1",
            "SentTimestamp":"1602046897707",
            "SenderId":"AIDAR3BXDV4FCWXL56NUU",
            "ApproximateFirstReceiveTimestamp":"1602046897712"
         },
         "messageAttributes":{

         },
         "md5OfBody":"98da683a47692b39c1d43bd4fa21ed89",
         "eventSource":"aws:sqs",
         "eventSourceARN":"arn:aws:sqs:ap-south-1:126817120010:documentation",
         "awsRegion":"ap-south-1"
      }
   ]
}

parsed = json.loads(event['Records'][0]['body'])
print(json.dumps(parsed, indent=4, sort_keys=True))

Output:

{
    "name": "aniket",
    "tag": "hello"
}

I'm not sure if this is what you want, but you can just do 'body': json_data. I tested this now in my λ function:

Lambda function

import json

def lambda_handler(event, context):

    json_data = [{"Dp_Record_Id": 2, 
                  "DP_TYPE": "NSDL",
                  "DP_ID": "40877589", 
                  "CLIENT_ID": "1232", 
                  "Default_flag": "Y"}]

    return {'statusCode': 200,
            'headers': {
            "Access-Control-Allow-Origin": "*",
            "Access-Control-Allow-Methods": 'GET, POST, PUT, DELETE, OPTIONS'
            },
            'body': json_data
        }    

Result

Response:
{
  "statusCode": 200,
  "headers": {
    "Access-Control-Allow-Origin": "*",
    "Access-Control-Allow-Methods": "GET, POST, PUT, DELETE, OPTIONS"
  },
  "body": [
    {
      "Dp_Record_Id": 2,
      "DP_TYPE": "NSDL",
      "DP_ID": "40877589",
      "CLIENT_ID": "1232",
      "Default_flag": "Y"
    }
  ]
}

Convert into dict and then try

import json
import boto3

s3 = boto3.client('s3')

def lambda_handler(event, context):

    
    s3_clientobj = s3.get_object(Bucket='avcdf-bulk-dev', Key='RIXML/josnfile.json')
    s3_clientdata = s3_clientobj['Body'].read().decode('utf-8')
    #print(s3_clientdata)
    clientdata_dict = json.loads(s3_clientdata)
    print(clientdata_dict)
    print(clientdata_dict['Research']['@researchID'])

Your question and objective have multiple pieces: - Q: How to handle encoding decimal values to JSON. - A: Use a custom encoder like how you are doing - Documentation: https://stackoverflow.com/questions/1960516/python-json-serialize-a-decimal-object - Q: Avoiding reserved words - A: Use ProjectionExpression with ExpressionAttributeNames like how you are doing - Documentation: https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html - Q: Simplest way to return a get response from DynamoDB using python - A: ``` import json import uuid import os import boto3 from datetime import datetime from decimal import Decimal class DecimalEncoder(json.JSONEncoder): def default(self, obj): if isinstance(obj, Decimal): return str(obj) return json.JSONEncoder.default(self, obj) # Prepare DynamoDB client USERS_TABLE = os.getenv('USERS_TABLE', None) dynamodb = boto3.resource('dynamodb') ddbTable = dynamodb.Table(USERS_TABLE) def lambda_handler(event, context): route_key = f"{event['httpMethod']} {event['resource']}" # Set default response, override with data from DynamoDB if any response_body = {'Message': 'Unsupported route'} status_code = 400 headers = { 'Content-Type': 'application/json', 'Access-Control-Allow-Origin': '*' } try: # Get a list of all Users if route_key == 'GET /users': ddb_response = ddbTable.scan(Select='ALL_ATTRIBUTES') # return list of items instead of full DynamoDB response response_body = ddb_response['Items'] status_code = 200 # CRUD operations for a single User # Read a user by ID if route_key == 'GET /users/{userid}': # get data from the database ddb_response = ddbTable.get_item( Key={'userid': event['pathParameters']['userid']} ) # return single item instead of full DynamoDB response if 'Item' in ddb_response: response_body = ddb_response['Item'] else: response_body = {} status_code = 200 except Exception as err: status_code = 400 response_body = {'Error:': str(err)} print(str(err)) return { 'statusCode': status_code, 'body': json.dumps(response_body, cls=DecimalEncoder), 'headers': headers } ``` Your `mapped_items` object is just remapping the same values as exist in the items response, so if you don't need to rename those values in the json, you don't need that step. For example, this is the body of your response with and without the mapped_items: With mapped_items ``` [{\"col1\": \"1\", \"col2\": \"2\", \"col3\": \"3\", \"col4\": \"4\", \"col5\": \"5\", \"owner\": \"ddd\"}] ``` Without mapped_items (just returning response["Items"]) ``` [{\"col3\": \"3\", \"col4\": \"4\", \"col5\": \"5\", \"owner\": \"ddd\", \"col1\": \"1\", \"col2\": \"2\"}] ``` Also, it is better practice to establish the dynamoDB connection outside of the request handler (this is demonstrated in the above code). That way, if a warm invocation occurs, that invocation will use the existing dynamodDB connection and complete quicker References: https://catalog.workshops.aws/serverless-patterns/en-US

So there are 3 problems:

Problem 1: In your example event, ['Records'][0]['Sns']['Message'] is a str in JSON format. That means that you need to parse to a dict like this:

 message = event['Records'][0]['Sns']['Message']
 message = json.loads(message)

Problem 2: message['Trigger']['Dimensions'] is a list but you are trying to access it like if it were a dict. So you only need to change your code to:

message = message['Trigger']['Dimensions'][0]['name']

Problem 3: Message is a str that means that you need to verify that is a plain str or json str (otherwise you are going to have problems with multiple structures and types). For that your code could look like:

 message = event['Records'][0]['Sns']['Message']
    if isinstance(message, str):
        try:
            message = json.loads(message)
        except Exception as e:
            print(e) # Or do nothing, this is just to log the error
    elif isinstance(message, list):
        message = message[0]
    # Maybe evaluate bool, tuple, etc other types

    print('RESPONSE', message['Trigger']['Dimensions'][0]['name'] if isinstance(message, dict) else message)

However I would also recommend to make it more extensible iterating the elements that you know are list. And for safety reasons (trying to avoid null pointer exceptions), use the get() function with a default value. http://www.tutorialspoint.com/python/dictionary_get.htm . Try maybe to create a function to parse structures and make it reusable.

Good luck!

Your body is a string. You have to use ast parse it to valid python map:

import ast

body = ast.literal_eval(event['body'])

then you should be able to use body as regular map.

Alternative

import json

body = json.loads("{}".format(event['body']))