googleappengine SDK home page and app url issue

Question

url = http://localhost:8000/instances

app.yaml

application: 222999888
version: 1
runtime: python27
api_version: 1
threadsafe: true

libraries:
- name: webapp2
  version: "2.5.2"
- name: webob
  version: "1.2.3"

handlers:
- url: /favicon\.ico
  static_files: favicon.ico
  upload: favicon\.ico

- url: /hello
  script: main.app

main.py

import webapp2

class MainHandler(webapp2.RequestHandler):
    def get(self):
        self.response.write('Hello world!')

app = webapp2.WSGIApplication([('/', MainHandler)], debug=True)

Now I dont know how to access hello world text through http://localhost:8000/hello url because when I try to visit this url it says 404. where am I making mistake I'm following this page https://developers.google.com/appengine/training/intro/gettingstarted

PS: using ubuntu+python2.7.6+commandline interface

EDIT:

WARNING  2014-09-01 06:07:35,845 api_server.py:383] Could not initialize images API; you are likely missing the Python "PIL" module.
INFO     2014-09-01 06:07:35,848 api_server.py:171] Starting API server at: http://localhost:58535
INFO     2014-09-01 06:07:35,850 dispatcher.py:183] Starting module "default" running at: http://localhost:8080
INFO     2014-09-01 06:07:35,852 admin_server.py:117] Starting admin server at: http://localhost:8000
INFO     2014-09-01 06:08:10,090 module.py:652] default: "GET / HTTP/1.1" 404 -

Answer 1

The web server listens on port 8080 by default. You can visit the application at this URL: http://localhost:8080/.

What you were looking at is The Development Console.

Here's everything you need to know about The Python Development Server.