AWS s3 Put Event Lambda Code

lambda_handler.py

import json
import boto3

def lambda_handler(event, context):
    #1 create an s3 client object
	s3 = boto3.client("s3")
	
	#2 counters for the calculations
	addition_count = 0
	multiplication_count = 0

	#3 Get the bucket name
	bucket_name = event['Records'][0]['s3']['bucket']['name']

	#4 Get the file name
	key = event['Records'][0]['s3']['object']['key']

	try:
		#5 Fetch the file from s3
		response = s3.get_object(Bucket = bucket_name, Key = key)

		#6 Deserialise the file's contents
		contents = response["Body"].read().decode()

		#7 Parse the contents to dictionary
		data = json.loads(contents)

		#8 Print the dictionary
		print(data)

		#9 Process the dictionary
		calculations = data['calculations']

		for record in calculations:
			if record['operation'] == 'ADDITION':
				addition_count += 1
				first_num = record['first_num']
				second_num = record['second_num']
				result = first_num + second_num
				print("Addition of: {} and {} = {} ".format(first_num, second_num, result))
				
			elif record['operation'] == 'MULTIPLICATION':
				multiplication_count +=1
				first_num = record['first_num']
				second_num = record['second_num']
				result = first_num * second_num
				print("Multiplication of: {} and {} = {} ".format(first_num, second_num, result))

	except Exception as e:
		print(e)

	return {
		'statusCode': 200,
		'body': json.dumps("Addition operations: {}, Multiplication operations: {}".format(
		addition_count, multiplication_count))
	}