Example sub-mounted Flask application

app.py

from flask import Flask, url_for
from werkzeug.serving import run_simple
from werkzeug.wsgi import DispatcherMiddleware

app = Flask(__name__)

app.config["APPLICATION_ROOT"] = "/abc/123"

@app.route("/")
def index():
    return "The URL for this page is {}".format(url_for("index"))

def simple(env, resp):
    resp(b'200 OK', [(b'Content-Type', b'text/plain')])
    return [b"Hello WSGI World"]

parent_app = DispatcherMiddleware(simple, {"/abc/123": app})

if __name__ == "__main__":
    run_simple('localhost', 5000, parent_app)

requirements.txt

Flask==0.10.1