Sample Python 3.7 AWS Lambda SAM template.

hello__DASH__world.py

import json


def handler(event, context):
    body = {
        "message": "World",
        "input": event
    }

    response = {
        "statusCode": 200,
        "body": json.dumps(body)
    }

    return response

    # Use this code if you don't use the http event with the LAMBDA-PROXY
    # integration
    """
    return {
        "message": "Go Serverless v1.0! Your function executed successfully!",
        "event": event
    }
    """

template.yaml

AWSTemplateFormatVersion: '2010-09-09'
Transform: 'AWS::Serverless-2016-10-31'
Description: >-
  Image Processor with SAM and AWS Lambda
Resources:
  ImageProcessorHello:
    Type: 'AWS::Serverless::Function'
    Properties:
      Handler: world.handler
      Runtime: python3.7
      CodeUri: hello
      Description: >-
        Trying AWS Lambda for the first time
      MemorySize: 128
      Timeout: 3
      Events:
        http:
          Type: Api
          Properties:
            Path: /hello
            Method: GET