AWS Lambda JSON to DynamoDB KeyError Serializing JSON

Question

I am setting up my lambda function on AWS and want to insert my JSON into the DynamoDB (NoSQL). I think it has to do with the serialization of the JSON (decimal_serializer), but I might be wrong. Thanks for help!

I get following error while serializing this data:

Error MSG:

{
  "errorMessage": "'male_confidence'",
  "errorType": "KeyError"
}

JSON DATA to INSERT:

{
  "device_id": "abc876",
  "recorded_at": "1496136878",
  "customers": [
    {
      "male_confidence": "0.2",
      "female_confidence": "0.8"
    },
    {
      "male_confidence:": "0.1",
      "female_confidence": "0.9"
    }
  ]
}

Lambda Function Handler

import boto3
import json

def lambda_handler(event, context):
    # TODO implement
    client = boto3.client('dynamodb')
    for customer in event['customers']:
        client.put_item(TableName="cv_data_1", Item={'device_id': {"S": event['device_id']}, 'male_confindence': {"N": customer['male_confidence']}, 'female_confidence': {"N": customer['female_confidence']}, "timestamp":{ "N": event['recorded_at']}})
    print('Successfully processed %s items.' % str(len(event['customers'])))

AWS Output Log Error (Detail):

During handling of the above exception, another exception occurred:
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09:23:38
Traceback (most recent call last):
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File "/var/runtime/awslambda/bootstrap.py", line 463, in <module>
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main()
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File "/var/runtime/awslambda/bootstrap.py", line 459, in main
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handle_event_request(request_handler, invokeid, event_body, context_objs, invoked_function_arn)
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File "/var/runtime/awslambda/bootstrap.py", line 240, in handle_event_request
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result = to_json(result)
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File "/var/runtime/awslambda/bootstrap.py", line 215, in to_json
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return json.dumps(obj, default=decimal_serializer)
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File "/var/lang/lib/python3.6/json/__init__.py", line 238, in dumps
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**kw).encode(obj)
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File "/var/lang/lib/python3.6/json/encoder.py", line 199, in encode
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chunks = self.iterencode(o, _one_shot=True)
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File "/var/lang/lib/python3.6/json/encoder.py", line 257, in iterencode
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return _iterencode(o, 0)
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File "/var/runtime/awslambda/bootstrap.py", line 104, in decimal_serializer
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raise TypeError(repr(o) + " is not JSON serializable")

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TypeError: <FrameSummary file /var/task/lambda_function.py, line 8 in lambda_handler> is not JSON serializable

Answer 1

Typo:

  "male_confidence:": "0.1",
  "female_confidence": "0.9"

"male_confidence:"

Answer 2

You have a typo after male_confidence: , note the extra : . Try this

{
  "device_id": "abc876",
  "recorded_at": "1496136878",
  "customers": [
    {
      "male_confidence": "0.2",
      "female_confidence": "0.8"
    },
    {
      "male_confidence": "0.1",
      "female_confidence": "0.9"
    }
  ]
}