flask_openapi3_config.py

from flask import Flask, jsonify
from flasgger import Swagger
from flasgger import swag_from

app = Flask(__name__)

## this is required to give openapi version
## separately in the app.config 
## even though we mention it in docs.yml
app.config['SWAGGER'] = {
    "openapi": "3.0.0"
}

## docs.yml is the swagger documentation file
swagger = Swagger(app, template_file='docs.yml')

## using decorator @swag_form we can refer to the paths
## that we need to mention in docs.yml
@app.route('/helloworld', method=["GET"])
@swag_from
def hello_world:
	print("Hello World")
	return jsonify({"success": True, "message": "Done"})