Simple flask

main.py

from flask import Flask

app = Flask(__name__)

from myapp import myapp as myapp_blueprint
app.register_blueprint(myapp_blueprint)

if __name__ == '__main__':
    app.run(debug=True)

myapp __init__.py

from flask import Blueprint

myapp = Blueprint('myapp', __name__)

from . import views

myapp views.py

from flask import Blueprint

myapp = Blueprint('myapp', __name__)

@myapp.route('/')
def index():
    return "Hello world"