gistfile1.py

import webapp2
from google.appengine.api import memcache

class MainHandler(webapp2.RequestHandler):
    def get(self):
        user_count = memcache.get('user_count')
        if user_count is None:
            user_count = 0
        else:
            self.response.write('Got user count {} from memcache.<br>'.format(user_count))
        if not memcache.set('user_count', user_count + 1):
            self.response.write('Could not set memcache value!<br>')
        self.response.write('Hello world! You are visitor no. {}'.format(user_count + 1))

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