[FIXED] how can i retrieve value in JSON string in lambda python3

Issue

I'm developing an AWS lambda function that is triggered from an event bridge and then putting another event using python but struggling to retrieve a value from a variable in the Json string

below is the code

import json, boto3

client = boto3.client('events')

def lambda_handler(event, context):

testV2_dict={  
 "K1" : event['e1'] ,
"K2" : event['e2'] 
}

#converting python to json as (put_event - Details) section is expecting json
testV2=json.dumps(testV2_dict)

response = client.put_events(
         Entries=
          [
            {
             "DetailType": "test",
             "Source": "test",
             "Detail": "{ \"testK\": \"testV\",\"testK2\": \""+ testV2 +"\" }"
           }
          ]
        )

tried to add Details on different ways, "Detail": "{ \"testK\": \"testV\",\"testK2\": \""+ testV2 +"\" }" and still getting error as Malformated Details and if i deleted the ++, I'm getting word testV2 itself not the value from the above

How can I retrieve the value of testV2 in the Details inside the event?

Solution

You don't have enough escaping in there. If testV2 is supposed to be a JSON string emebedded in a JSON string embedded in as JSON string, then you need more string escapes. I would let json.dumps handle that:

import json
event = {'e1': 99, 'e2': 101}

testV2_dict={  
 "K1" : event['e1'] ,
 "K2" : event['e2'] 
}

testV2=json.dumps(testV2_dict)

detail = {
    "testK": "testV",
    "testK2": testV2
}

Entries= [
    {
     "DetailType": "test",
     "Source": "test",
     "Detail": json.dumps(detail),
   }
]

print(Entries)

Output:

[{'DetailType': 'test', 'Source': 'test', 'Detail': '{"testK": "testV", "testK2": "{\\"K1\\": 99, \\"K2\\": 101}"}'}]

Answered By - Tim Roberts

Answer Checked By - Timothy Miller (PHPFixing Admin)