should we write any code related to aws lambda in python file before deploying in aws lambda code example

Example: Deploy Python Application on AWS Lambda

# serverless.ymlservice: serverless-flask# These are the plugins you have installed to support WSGI and pip # requirementsplugins:  - serverless-python-requirements  - serverless-wsgicustom:  wsgi:    # This is the file name and the app name of the application     # Where file name is app.py and Flask app name is app    # ie. app = Flask(__name__)     app: app.app    packRequirements: false  pythonRequirements:    dockerizePip: non-linuxprovider:  name: aws  runtime: python3.6  stage: dev  region: us-east-1functions:  app:    handler: wsgi.handler    events:      - http: ANY /      - http: 'ANY {proxy+}'