simpler solution

webui.py

import threading
from wsgiref.simple_server import make_server
from mylongtask import progress_status, run_task


# simple wsgi app; could replace with one from flask with templates,
# url dispatching, etc.
def simple_app(environ, start_response):
    start_response('200 OK', [('Content-Type', 'text/plain')])
    return [str(progress_status)]


class TaskThread(threading.Thread):
    def run(self):
        # instead of just running the task, you could pull tasks
        # off using the stdlib Queue module, and add a Flask
        # endpoint for adding tasks onto the Queue. Fancy.
        run_task()


class WebThread(threading.Thread):
    def run(self):
        httpd = make_server('', 8000, simple_app)
        print "Serving on port 8000..."
        httpd.serve_forever()

w = WebThread()
t = TaskThread()
w.start()
t.start()