Passing Functions

[yoro]

On Mar 11, 2:00 am, MRAB <pyt... at mrabarnett.plus.com> wrote:
> On 11/03/2011 01:13, yoro wrote:
>
> > Hi,
>
> > I am having an issue with passing values from one function to another
> > - I am trying to fill a list in one function using the values
> > contained in other functions as seen below:
>
> > infinity = 1000000
> > invalid_node = -1
> > startNode = 0
>
> > #Values to assign to each node
> > class Node:
> >       distFromSource = infinity
> >       previous = invalid_node
> >       visited = False
>
> > #read in all network nodes
> > def network():
> >      f = open ('network.txt', 'r')
> >      theNetwork = [[int(node) for node in line.split(',')] for line in
> > f.readlines()]
> >      print theNetwork
>
> >      return theNetwork
>
> > #for each node assign default values
> > def populateNodeTable():
> >      nodeTable = []
> >      index = 0
> >      f = open('network.txt', 'r')
> >      for line in f:
> >        node = map(int, line.split(','))
> >        nodeTable.append(Node())
>
> >        print "The previous node is " ,nodeTable[index].previous
> >        print "The distance from source is
> > " ,nodeTable[index].distFromSource
> >        index +=1
> >      nodeTable[startNode].distFromSource = 0
>
> >      return nodeTable
>
> > #find the nearest neighbour to a particular node
> > def nearestNeighbour(currentNode, theNetwork):
> >       nearestNeighbour = []
> >       nodeIndex = 0
> >       for node in nodeTable:
> >            if node != 0 and currentNode.visited == false:
> >               nearestNeighbour.append(nodeIndex)
> >               nodeIndex +=1
>
> >       return nearestNeighbour
>
> > if __name__ == "__main__":
> >      nodeTable = populateNodeTable()
> >      theNetwork = network()
> >      nearestNeighbour(currentNode, theNetwork, )
>
> > So, I am trying to look at the values provided by the network
> > function,  set all nodes to 'visited = false' in populateNodeTable
> > function and then determine the nodes' nearest neighbour by looking at
> > the values provided in the previous function, though I get this error
> > message:
>
> > if node != 0 and currentNode.visited == false:
> > AttributeError: 'int' object has no attribute 'visited'
>
> > I'm not sure what to try next
>
> In nearestNeighbour, 'currentNode' is an int because that's what you're
> passing in ... except that you aren't.
>
> You're passing in the value of the global 'currentNode', which doesn't
> exist. Perhaps you meant 'startNode'?
>
> When I run the above program I get:
>
> Traceback (most recent call last):
>    File "C:\Documents and Settings\Administrator\Desktop\network.py",
> line 49, in <module>
>      nearestNeighbour(currentNode, theNetwork, )
> NameError: name 'currentNode' is not defined

I've found the error, I had to type in:

for node in nodeTable:
          if node != 0 and Node.visited == False: