Problem in implementing Romania Map using Paython Script

Mon Nov 2 00:30:19 EST 2015

Dear all;
I want to code algorithm in Python for driving from Arad to Bucharest as quickly as possible.
I formulated the problem in python as following :
1- States : Various cities.
2- Actions : Drive distances between different cities.
3- Goal : To be in Bucharest.
class Problem:
 def __init__(self, initial, goal=None):

 self.initial = initial
 self.goal = goal

 def goalTest(self, state):

 return state == self.goal
But the problem now is with Roaming and Node classifications :
class RoamingProblem(Problem): 
 def successors(self, state):
Q1 : How I can complete the class RoamingProblem (Problem) and include action costs.
I think its related in some how in using a new city map ????...
And how I can return the cost next state ????...
list of tuples [(action1,[(action1, successor-state1, cost1, action2, successor-state2, cost2 ...)]
Q2 : For the class node 
class Node:
 def __init__(self, state, parent=None, action=None, pathCost=0):
 self.state = state
 self.parent = parent
 self.action = action
 self.pathCost = pathCost
 update(state,parent,action,pathcost,depth)
 def expand(self, problem):

 return [Node(next,self,action,problem,....].
THE last line How I can return : list of Node objects, one for each successor state, parent of the created nodes is self ????....
I need a help in completing the Class Roaming problem using Euclidean function , Completing the Class Node .....
And def treesearch and graph search problem ?????
Waiting for reply ????