title: How do you unstring a string?
body: <p>I need to call a method on an object but I keep getting an error: </p>
  
  <p><code>'str' object has no attribute 'go'</code></p>
  
  <p>I'm doing a web app and I need to load a new room when the user submits a form. </p>
  
  <pre><code>class GameEngine(object):
  
      def GET(self):
          if session.room:
              return render.show_room(room=session.room)
          else:
              return render.you_died()
  
      def POST(self):
          form = web.input(action=None)
  
          if session.room and form.action:
              session.room = session.room.go(form.action)
  
          web.seeother("/game")
  </code></pre>
  
  <p>Each session.room has paths and go is supposed to move you to whatever path you chose in the form. How do I fix this bug? </p>
  
  <p>I would like to go to the new room and render it. The problem is in the </p>
  
  <pre><code>if session.room and form.action:
      session.room = session.room.go(form.action) 
  </code></pre>
  
  <p>Here is the whole app.py file:</p>
  
  <pre><code>import web  
  from gothonweb import map
  
  urls = (
  '/game', 'GameEngine',
  '/', 'Index',
  )
  
  app = web.application(urls, globals())
  
  if web.config.get('_session') is None:
      store = web.session.DiskStore('sessions')
      session = web.session.Session(app, store,
                                initializer={'room': None})
      web.config._session = session
  else:
      session = web.config._session
  
  render = web.template.render('templates/', base="layout")
  
  
  class Index(object):
      def GET(self):
          session.room = map.START
          web.seeother("/game")
  
  
  class GameEngine(object):
  
      def GET(self):
          if session.room:
              return render.show_room(room=session.room)
          else:
              return render.you_died()
  
      def POST(self):
          form = web.input(action=None)
  
          if session.room and form.action:
              session.room = session.room.go(form.action)
              return render.show_room(room=session.room)
  
          web.seeother("/game")
  
  if __name__ == "__main__":
      app.run()
  </code></pre>
  
  <p>Here is the gothonweb/map.py file:</p>
  
  <pre><code>from random import randint
  
  class Room(object):
  
      def __init__(self, name, description):
          self.name = name
          self.description = description
          self.paths = {}
  
      def go(self, direction):
          return self.paths.get(direction, None)
  
      def add_paths(self, paths):
          self.paths.update(paths)
  
  central_corridor = Room("Central Corridor",
  """
  The Gothons of Planet Percal #25 have invaded your ship and destroyed
  your entire crew.  You are the last surviving member and your last
  mission is to get the neutron destruct bomb from the Weapons Armory,
  put it in the bridge, and blow the ship up after getting into an 
  escape pod.
  
  You're running down the central corridor to the Weapons Armory when
  a Gothon jumps out, red scaly skin, dark grimy teeth, and evil clown costume
  flowing around his hate filled body.  He's blocking the door to the
  Armory and about to pull a weapon to blast you.
  """)
  
  
  laser_weapon_armory = Room("Laser Weapon Armory",
  """
  Lucky for you they made you learn Gothon insults in the academy.
  You tell the one Gothon joke you know:
  Lbhe zbgure vf fb sng, jura fur fvgf nebhaq gur ubhfr, fur fvgf nebhaq gur ubhfr.
  The Gothon stops, tries not to laugh, then busts out laughing and can't move.
  While he's laughing you run up and shoot him square in the head
  putting him down, then jump through the Weapon Armory door.
  
  You do a dive roll into the Weapon Armory, crouch and scan the room
  for more Gothons that might be hiding.  It's dead quiet, too quiet.
  You stand up and run to the far side of the room and find the
  neutron bomb in its container.  There's a keypad lock on the box
  and you need the code to get the bomb out.  If you get the code
  wrong 10 times then the lock closes forever and you can't
  get the bomb.  The code is 3 digits.
  """)
  
  
  the_bridge = Room("The Bridge",
  """
  The container clicks open and the seal breaks, letting gas out.
  You grab the neutron bomb and run as fast as you can to the
  bridge where you must place it in the right spot.
  
  You burst onto the Bridge with the netron destruct bomb
  under your arm and surprise 5 Gothons who are trying to
  take control of the ship.  Each of them has an even uglier
  clown costume than the last.  They haven't pulled their
  weapons out yet, as they see the active bomb under your
  arm and don't want to set it off.
  """)
  
  
  escape_pod = Room("Escape Pod",
  """
  You point your blaster at the bomb under your arm
  and the Gothons put their hands up and start to sweat.
  You inch backward to the door, open it, and then carefully
  place the bomb on the floor, pointing your blaster at it.
  You then jump back through the door, punch the close button
  and blast the lock so the Gothons can't get out.
  Now that the bomb is placed you run to the escape pod to
  get off this tin can.
  
  You rush through the ship desperately trying to make it to
   the escape pod before the whole ship explodes.  It seems like
  hardly any Gothons are on the ship, so your run is clear of
  interference.  You get to the chamber with the escape pods, and
  now need to pick one to take.  Some of them could be damaged
  but you don't have time to look.  There's 5 pods, which one
  do you take?
  """)
  
  pod = randint(1,6)
  the_end_winner = Room("The End",
  """
  You jump into pod %r and hit the eject button.
  The pod easily slides out into space heading to
  the planet below.  As it flies to the planet, you look
  back and see your ship implode then explode like a
  bright star, taking out the Gothon ship at the same
  time.  You won!
  """ % pod)
  
  
  the_end_loser = Room("The End",
  """
  You jump into a random pod and hit the eject button.
  The pod escapes out into the void of space, then
  implodes as the hull ruptures, crushing your body
  into jam jelly.
  """
  )
  rn = randint(1,4)
  
  escape_pod.add_paths({
      '%r' % pod : the_end_winner,
      '*': the_end_loser
  })
  
  generic_death = {1: "You died. You kinda suck at this.",
  2:"Your mom would be proud...if she were smarter.",
  3:"Such a luser.",
  4:"I have a small puppy that's better at this."}
  
  the_bridge.add_paths({
  'throw the bomb': generic_death[rn],
  'slowly place the bomb': escape_pod
  })
  
  randcode = '%r%r' % (randint(0,9),randint(0,9))
  laser_weapon_armory.add_paths({
  randcode : the_bridge,
  '*': generic_death[rn]
  })
  
  central_corridor.add_paths({
  'shoot!': generic_death[rn],
  'dodge!': generic_death[rn],
  'tell a joke': laser_weapon_armory
  })
  
  START = central_corridor
  </code></pre>