flask

from werkzeug.wrappers import Request,Response
from werkzeug.serving import run_simple
def run(environ,start_response):
    return [b‘Hello,World‘]
if __name__ ==‘__main__‘:
    run_simple(‘localhost‘,4000,run)

from werkzeug.wrappers import Request,Response
@Request.application
def hello(request):
    return Response(‘Hello World!‘)
if __name__ ==‘__main__‘:
    from werkzeug.serving import run_simple
    run_simple(‘localhost‘,4000,hello)

from flask import Flask
app = Flask(__name__)
@app.route(‘/index‘)
def index():
    return "Hello World"
if __name__ ==‘__main__‘:
    app.run()