This is a Lambda function that's get triggers when a file is uploaded to an s3 bucket. I wrote it in such a way that if an image or a json file is uploaded to the s3 bucket the lambda func is able to process it.

s3_trigger_lambda_func.py

import json
import urllib.parse
import boto3

print('Loading function')

s3 = boto3.client('s3')


def lambda_handler(event, context):
    #print("Received event: " + json.dumps(event, indent=2))

    # Get the object from the event and show its content type
    bucket = event['Records'][0]['s3']['bucket']['name']
    key = urllib.parse.unquote_plus(event['Records'][0]['s3']['object']['key'], encoding='utf-8')
    try:
        response = s3.get_object(Bucket=bucket, Key=key)
        
        condition = response['ContentType']
        
        if(condition) == "image/jpeg":
            print("CONTENT TYPE: " + response['ContentType'])
            return "Success, read an Image"
        
        elif(condition) == "application/json":
            text = response['Body'].read().decode()
            data = json.loads(text)
            
            print(data)
            
            transaction = data['transactions']
            for record in transaction:
                print(record['transType'])
            return "Success, read a json"
    
    except Exception as e:
        print(e)
        print('Error getting object {} from bucket {}. Make sure they exist and your bucket is in the same region as this function.'.format(key, bucket))
        raise e