running flask app using python's built-in wsgiref

wsgiref_flask.py

# call this server using the following js command from the browser console:
# (await fetch('http://localhost:5000/', {method: "POST", body: '5'})).text()
# note: wsgiref is only good for development and in that case Werkzeug is 
# usually preferred. See http://mitsuhiko.pocoo.org/wzdoc/wsgihowto.html

from wsgiref.simple_server import make_server
from flask import Flask, request, Response


app = Flask(__name__)


# the default method is 'GET'
@app.route('/', methods=['GET', 'POST'])
def foobar():
    print(request.data)
    # the header is required to get over the CORS policy of the browsers
    return Response('foo bar', headers=(('Access-Control-Allow-Origin', '*'),))


server = make_server('localhost', 5000, app)

# serve_forever runs in a loop. to serve only a single request use:
# server.handle_request()
server.serve_forever()