Question

Ok, I have changed my code a little, but I am getting confused on what variable names should be passed to my nearestNeighbour function. These two functions work ok:

infinity = 1000000
invalid_node = -1
startNode = 0

#Values to assign to each node
class Node:
     def __init__(self):
       self.distFromSource = infinity
       self.previous = invalid_node
       self.visited = False

#read in all network nodes
#node = the distance values between nodes
def network():
    f = open ('network.txt', 'r')
    theNetwork = [[int(networkNode) for networkNode in line.split(',')] for line in f.readlines()]
    #theNetwork = [[int(node) for node in line.split(',')] for line in f.readlines()]
    #print theNetwork

    return theNetwork

#for each node assign default values
#populate table with default values
def populateNodeTable(): 
    nodeTable = []
    index = 0
    f = open('network.txt', 'r')
    for line in f: 
      networkNode = map(int, line.split(',')) 
      nodeTable.append(Node())

      #print "The previous node is " ,nodeTable[index].previous 
      #print "The distance from source is " ,nodeTable[index].distFromSource
      #print networkNode
      index +=1
    nodeTable[startNode].distFromSource = 0 

    return nodeTable

So, all well and good. However, my next function is giving me an error, and despite me changing variable names in the brackets I can’t work out the problem. Here is the next function code and the error message:

def nearestNeighbour(nodeTable, theNetwork):
     listOfNeighbours = []
     nodeIndex = 0
     for networkNode in nodeTable[currentNode]:
          if networkNode != 0 and networkNode.visited == False: 
             listOfNeighbours.append(nearestNode)
          nodeIndex +=1
     print listOfNeighbours
##     #print node.distFromSource, node.previous, node.visited
##
     return listOfNeighbours

for networkNode in nodeTable[currentNode]:
TypeError: iteration over non-sequence

Answer 1

I think you want nodeTable[node], not node[nodeTable], and similarly with theNetwork[node].