new_contents:  # Copyright 2014 Google Inc. All rights reserved.
   #
   # Licensed under the Apache License, Version 2.0 (the "License");
   # you may not use this file except in compliance with the License.
   # You may obtain a copy of the License at
   #
   #   http://www.apache.org/licenses/LICENSE-2.0
   #
   # Unless required by applicable law or agreed to in writing, software
   # distributed under the License is distributed on an "AS IS" BASIS,
   # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   # See the License for the specific language governing permissions and
   # limitations under the License
  
  import os
  import jinja2
  import webapp2
  
  JINJA_ENVIRONMENT = jinja2.Environment(
      loader=jinja2.FileSystemLoader(os.path.dirname(__file__)),
      extensions=['jinja2.ext.autoescape'],
      autoescape=True)
  
  class MainPage(webapp2.RequestHandler):
  
      def choose_template_from_url(self, url):
  
          deeplink_class = ''
  
          if (url != '/'):
              deeplink_class = 'app-deeplink'
  
          return {
              'path': 'dist/index.html',
              'data': {
                  'deeplink_class': deeplink_class
              }
          }
  
      def get(self, url):
  
          template_data = self.choose_template_from_url(url)
          template = JINJA_ENVIRONMENT.get_template(template_data['path'])
          self.response.write(template.render(template_data['data']))
  
  app = webapp2.WSGIApplication([
      ('(.*)', MainPage),
  ], debug=False)
  
subject: add template.py