Question

I’m able to go through the first function….but the second func is not running….getaction

 def registerInitialState(self, state):
    """
    This is the first time that the agent sees the layout of the game board. Here, we
    choose a path to the goal.  In this phase, the agent should compute the path to the
    goal and store it in a local variable.  All of the work is done in this method!

    state: a GameState object (pacman.py)
    """
    if self.searchFunction == None: raise Exception, "No search function provided for SearchAgent"
    starttime = time.time()
    problem = self.searchType(state) # Makes a new search problem
    self.actions  = self.searchFunction(problem) # Find a path
    totalCost = problem.getCostOfActions(self.actions)
    print('Path found with total cost of %d in %.1f seconds' % (totalCost, time.time() - starttime))
    if '_expanded' in dir(problem): print('Search nodes expanded: %d' % problem._expanded)

  def getAction(self, state):
    """
    Returns the next action in the path chosen earlier (in registerInitialState).  Return
    Directions.STOP if there is no further action to take.

    state: a GameState object (pacman.py)
    """
    if 'actionIndex' not in dir(self): self.actionIndex = 0
    i = self.actionIndex
    self.actionIndex += 1
    if i < len(self.actions):
      return self.actions[i]    
    else:
      return Directions.STOP


Error:  File  line 114, in getAction
    if i < len(self.actions):
TypeError: len() of unsized object

this is my function:when i execute, it shud give me the value of node but instead of it, it is giving me error. The value of i = 0 in the get action function. I dont know, why it is not incrementing.

while stack.isEmpty()!= 0:  
        node = stack.pop()
        print node

Error:

(5, 5)
Path found with total cost of 999999 in 0.0 seconds
Search nodes expanded: 1
None

Answer 1

Add the print statement as per below and tell me what it says. self.actions is probably the None type or not a list-like object. You might want to check == None like the other one.

self.actionIndex += 1 
print self.actions
if i < len(self.actions): 
  return self.actions[i]     
else: 
  return Directions.STOP 

So the problem is probably somewhere in here:

problem = self.searchType(state) # Makes a new search problem 
self.actions  = self.searchFunction(problem) # Find a path 

making self.actions == None

You could debug further with:

problem = self.searchType(state) # Makes a new search problem 
print problem
self.actions  = self.searchFunction(problem) # Find a path 

to check if problem is working.. if so, searchFunction is not finding the path or something is going wrong and it is returning None.