Algoritmo MST(Gasoduto)

import sys  # Library for INT_MAX

class Graph():

    def __init__(self, vertices):
        self.V = vertices
        self.graph = [[0 for column in range(vertices)]
                      for row in range(vertices)]

    # A utility function to print the constructed MST stored in parent[]
    def printMST(self, parent):
        print "Edge \tWeight"
        for i in range(1,self.V):
            print parent[i],"-",i,"\t",self.graph[i][ parent[i] ]

    def minKey(self, key, mstSet):
        min = sys.maxint

        for v in range(self.V):
            if key[v] < min and mstSet[v] == False:
                min = key[v]
                min_index = v

        return min_index
    def primMST(self):
        key = [sys.maxint] * self.V
        parent = [None] * self.V # Array to store constructed MST
        key[0] = 0   # Make key 0 so that this vertex is picked as first vertex
        mstSet = [False] * self.V

        parent[0] = -1  # First node is always the root of

        for cout in range(self.V):
            u = self.minKey(key, mstSet)

            # Put the minimum distance vertex in the shortest path tree
            mstSet[u] = True

            for v in range(self.V):
                if self.graph[u][v] > 0 and mstSet[v] == False and key[v] > self.graph[u][v]:
                        key[v] = self.graph[u][v]
                        parent[v] = u

        self.printMST(parent)

g  = Graph(10)
g.graph = [
    [0,4230,4700,4716,4690, 4674, 5070,4880,4280,3880],
    [4230,0,534,682,950, 780, 1110,1190,2700,3100],
    [4700,534,0,190,544, 288, 787,1092,2600,3000],
    [4716,682,190,0,378, 122, 620,926,2436,2830],
    [4690,950,544,378,0, 256, 280,580,2100,2436],
    [4674,780,288,122,256, 0, 500,810,2320,2710],
    [5070,1110,787,620,280, 500, 0,330,1840,2200],
    [4880,1190,1092,926,580, 810, 330,0,1650,1985],
    [4280,2700,2600,2436,2100, 2320, 1840,1650,0,450],
    [3880,3100,3000,2830,2436, 2710, 2200,1985,450,0]
    ]

g.primMST();