CODEWITHSUNDEEP
jsonpython-3.xamazon-s3amazon-sqs
AWS_Beginner
AWS_Beginner

Reputation: 466

Extracting from Json

From one of the method i am getting below output

        {'Records': [{'messageId': '2953dfd5-d848-42b2-a60b-43df00ec8e5f', 
       'receiptHandle': 'AQEBPMr5RbW3T2DG4pAYi+', 'body': 
      'I am still trying', 'attributes': {'ApproximateReceiveCount': '1', 
        'SentTimestamp': '1552073955807', 'SenderId': '944198216610', 
        'ApproximateFirstReceiveTimestamp': '1552073955816'}, 
        'messageAttributes': {}, 'md5OfBody': 
         '2111a742ddbdac2d862fa6a204f7dc85', 'eventSource': 'aws:sqs', 
          'eventSourceARN': 'arn:aws:sqs:us-east- 
         1:944198216610:LambadaQueue', 'awsRegion': 'us-east-1'}]}

Now i want to fetch the value of body from this so i have used below

body=event['Records'][0][0]['body']

But this is not working.Can you please help me figure out what wrong i am doing?

Upvotes: 0

Views: 85

Answers (2)

amanb
amanb

Reputation: 5463

What am I doing wrong?

The Records key is a list and you can select items from a list using the index number for that item. 

json_string = {
              "Records": [
    {
      "messageId": "2953dfd5-d848-42b2-a60b-43df00ec8e5f",
      "receiptHandle": "AQEBPMr5RbW3T2DG4pAYi+",
      "body": "I am still trying",
      "attributes": {
        "ApproximateReceiveCount": "1",
        "SentTimestamp": "1552073955807",
        "SenderId": "944198216610",
        "ApproximateFirstReceiveTimestamp": "1552073955816"
      },
      "messageAttributes": { },
      "md5OfBody": "2111a742ddbdac2d862fa6a204f7dc85",
      "eventSource": "aws:sqs",
      "eventSourceARN": "arn:aws:sqs:us-east-1:944198216610: LambadaQueue",
      "awsRegion": "us-east-1"
    }
  ]
}

So, when you do json_string['Records'][0], this selects the first item in the list which is again a dictionary:

{
  "messageId": "2953dfd5-d848-42b2-a60b-43df00ec8e5f",
  "receiptHandle": "AQEBPMr5RbW3T2DG4pAYi+",
  "body": "I am still trying",
 ....}

Now if you do json_string['Records'][0][0], you are trying to access a dictionary key like an item in a list(using index number 0) which is syntacticaly incorrect. You can access the key by name such as json_string['Records'][0]['messageId'] if you want to access the value for 'messageId', or as in your question, the "body" key's value like this:

`json_string['Records'][0]['body']`

 #Output:
 I am still trying

Upvotes: 1

Will T
Will T

Reputation: 614

If you're attempting to get the value of the "body" element, it looks like you should just skip the second [0] in your lookup. Properly formatted, it looks like this:

{
  "Records": [
    {
      "messageId": "2953dfd5-d848-42b2-a60b-43df00ec8e5f",
      "receiptHandle": "AQEBPMr5RbW3T2DG4pAYi+",
      "body": "I am still trying",
      "attributes": {
        "ApproximateReceiveCount": "1",
        "SentTimestamp": "1552073955807",
        "SenderId": "944198216610",
        "ApproximateFirstReceiveTimestamp": "1552073955816"
      },
      "messageAttributes": { },
      "md5OfBody": "2111a742ddbdac2d862fa6a204f7dc85",
      "eventSource": "aws:sqs",
      "eventSourceARN": "arn:aws:sqs:us-east-1:944198216610: LambadaQueue",
      "awsRegion": "us-east-1"
    }
  ]
}

So, to get the value of the field "body" for the first record in "Records", it looks like you should do: body=event['Records'][0]['body']

Upvotes: 0

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