Recursive function call fails to recurse in AWS Lambda - Python3

Question

Im trying to replace python dictionary key with a different key name recursively for which i am using aws lambda with a api endpoint to trigger. Suprisingly the recursion part fails for weird reason. The same code works fine in local.

Checked cloudwatch logs. No error message get displayed there. Let me know if im missing anything here

EDIT: Related to Unable to invoke a recursive function with AWS Lambda and recursive lambda function never seems to run

### function that is called inside lambda_handler

def replace_recursive(data,mapping):
    for dict1 in data:
        for k,v in dict1.copy().items():
            if isinstance(v,dict):
                dict1[k] = replace_recursive([v], mapping)
            try:
                dict1[mapping['value'][mapping['key'].index(k)]] = dict1.pop(mapping['key'][mapping['key'].index(k)])
            except KeyError:
                continue
    return data

## lambda handler

def lambda_handler(events,_):
    resp = {'statusCode': 200}
    parsed_events = json.loads(events['body'])
    if parsed_events:
        op = replace_recursive(parsed_events,schema)
        resp['body'] = json.dumps(op)
    return resp

Input I pass:

{
  "name": "michael",
  "age": 35,
  "family": {
    "name": "john",
    "relation": "father"
  }
}

In the output, keys in the nested dictionary are not getting updated. Only outer keys get modified

Answer 1

Since you're ingesting JSON, you can do the key replacement right in the parse phase for a faster and simpler experience using the object_pairs_hook argument to json.loads .

import json

key_mapping = {
    "name": "noot",
    "age": "doot",
    "relation": "root",
}


def lambda_handler(events, _):
    replaced_events = json.loads(
        events["body"],
        object_pairs_hook=lambda pairs: dict(
            (key_mapping.get(k, k), v) for k, v in pairs
        ),
    )
    return {
        "statusCode": 200,
        "body": json.dumps(replaced_events),
    }


body = {
    "name": "michael",
    "age": 35,
    "family": {"name": "john", "relation": "father"},
}
print(
    lambda_handler(
        {
            "body": json.dumps(body),
        },
        None,
    )
)

prints out

{'statusCode': 200, 'body': '{"noot": "michael", "doot": 35, "family": {"noot": "john", "root": "father"}}'}