old_contents: #!/usr/bin/env python
  """A simple web server using CherryPy. It's good for prototyping REST API.
  
  Synopsis:
      cherrypy_web_server.py
  
     Copyright 2016 Heung Ming Tai
  
     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.
  """
  from __future__ import print_function
  from __future__ import absolute_import
  from __future__ import division
  from __future__ import unicode_literals
  
  import argparse
  import cherrypy
  
  
  class HelloWorld(object):
      @cherrypy.expose
      def index(self):
          return "Hello World!"
  
      @cherrypy.expose
      def echo(self, se=None):
          return se
  
  def parse_args():
      parser = argparse.ArgumentParser()
      parser.add_argument(
          "-p",
          "--port",
          type=int,
          default=8080,
          help="Port number of the server",
      )
      return parser.parse_args()
  
  if __name__ == '__main__':
      args = parse_args()
      cherrypy.config.update({'server.socket_port': args.port})
      cherrypy.quickstart(HelloWorld())
  
new_contents: #!/usr/bin/env python
  """A simple web server using CherryPy. It's good for prototyping REST API.
  
  Synopsis:
      cherrypy_web_server.py
  
     Copyright 2016 Heung Ming Tai
  
     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.
  """
  from __future__ import print_function
  from __future__ import absolute_import
  from __future__ import division
  from __future__ import unicode_literals
  
  import argparse
  import cherrypy
  
  
  class HelloWorld(object):
      @cherrypy.expose
      def index(self):
          return "Hello World!"
  
      @cherrypy.expose
      def echo(self, se=None):
          return se
  
  def parse_args():
      parser = argparse.ArgumentParser()
      parser.add_argument(
          "-p",
          "--port",
          type=int,
          default=8080,
          help="Port number of the server",
      )
      parser.add_argument(
          "-h",
          "--host",
          default="localhost",
          help="The host that the server binds to",
      )
      return parser.parse_args()
  
  if __name__ == '__main__':
      args = parse_args()
      cherrypy.config.update(
          {
              'server.socket_port': args.port,
              'server.socket_host': args.host,
          }
      )
      cherrypy.quickstart(HelloWorld())
  
subject: Add --host option