获取错误参数 Item 的类型无效，值：类型：<class 'list'> , 有效类型：<class 'dict'> 将 S3 加载到 DynamoDB 时

Question

I am new to AWS and learning. I have a JSON file with details of employees in S3 folder. Wrote a Lambda function with PYTHON 3.6 to load DynamoDB table XXXXX-YYYY-ZZZZ-Employees when the JSON file is uploaded to S3. All setups have been done with policy and roles to access CloudwatchLog, S3 and DynamoDB. Log file gives the error below. It appears that the issue is the file is a dictionary format like [] and the put_item expects string.. not sure.

(empid is the primary key)

Reviewed code and researched issue in google and AWS forums

import boto3

import json

s3_client = boto3.client('s3')
dynamodb = boto3.resource('dynamodb')
def lambda_handler(event, context):
    bucket = event['Records'][0]['s3']['bucket']['name']
    json_file_name = event['Records'][0]['s3']['object']['key']
    json_object = s3_client.get_object(Bucket=bucket,   Key=json_file_name)
    jsonFileReader = json_object['Body'].read()
    #print(jsonFileReader)
    jsonDict = json.loads(jsonFileReader)
    #print(jsonDict)
    table = dynamodb.Table('XXXXXX-YYYYY-ZZZZZZ-Employees')
    table.put_item(Item=jsonDict)    
return {
    'statusCode': 200,
    'body': json.dumps('Hello from Lambda!')
}

Expected result: DynamoDB table loaded with JSON file data Actual Result: getting error in cloudwatchlog:

Invalid type for parameter Item, value: [{'empid': 10004, 'email': 'test1@email.com', 'firstname': 'John5', 'lastname': 'Smith5', 'location': 'ABCD-B207', 'mobile': '123-456-7890', 'work': '098-765-4321', 'site': 'ABCD'}, {'empid': 10005, 'email': 'test1@email.com', 'firstname': 'John6',................. '}], type: , valid types:

Answer 1

Your programming is reading the entire file into jsonDict . You are then attempting to insert one item using the dictionary.

Instead, you should extract one line at a time, then use put_item() to insert one item. Repeat for each line.

Something like this might be possible:

jsonDict = json.loads(jsonFileReader)
table = dynamodb.Table('XXXXXX-YYYYY-ZZZZZZ-Employees')
for item in jsonDict:
    table.put_item(Item=item)