我在 Dijkstra 算法中确定最近邻居时遇到了困难。我得到如下奇怪的结果首先这是我的网络文件的内容，代表 7 个节点之间的距离：
（不包括第一列中的数字 1-7）
现在我的代码：
> 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
> #node = the distance values between 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
> #populate table with 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(nodeTable,
> theNetwork):
> nearestNeighbour = []
> nodeIndex = 0
> for node in nodeTable:
> if node != 0 and Node.visited == False:
> nearestNeighbour.append(nodeIndex)
> nodeIndex +=1
> print nearestNeighbour
>
> return nearestNeighbour
>
> def tentativeDistance (theNetwork,
> nodeTable, nearestNeighbour):
> shortestPath = []
> for nodeIndex in nearestNeighbour:
> currentDistance = nearestNeighbour[] + startNode
> print currentDistance
> ## if currentDistance < Node.distFromSource:
> ## theNetwork[Node].previous = nodeIndex
> ## theNetwork[Node].length = nodeIndex
> ## theNetwork[Node].visited = True;
> ## shortestPath.append(indexNode)
> ## nodeIndex +=1
> ## print shortestPath
>
> currentNode = startNode
>
> if __name__ == "__main__":
> nodeTable = populateNodeTable()
> theNetwork = network()
> nearestNeighbour(nodeTable, theNetwork)
> tentativeDistance(theNetwork, nodeTable, nearestNeighbour)
因此，我试图查看网络函数提供的值，在 populateNodeTable 函数中将所有节点设置为“已访问 = false”，然后通过查看前一个函数中提供的值来确定节点的最近邻居，尽管我得到了此错误消息：
> Traceback (most recent call last):
> File "C:\Documents and Settings\Harvey\Desktop\2dArray.py", line 77, in <module>
> tentativeDistance(theNetwork, nodeTable, nearestNeighbour) File
> "C:\Documents and Settings\Harvey\Desktop\2dArray.py", line 51, in tentativeDistance
> for nodeIndex in nearestNeighbour: TypeError: 'function' object is not iterable
当我刚刚运行我的网络功能时，我得到了这个输出：
[[0, 2, 4, 1, 6, 0, 0], [2, 0, 0, 0, 5, 0, 0], [4, 0, 0, 0, 5, 5, 0], [1, 0, 0, 0, 1, 1, 0], [6, 5, 0, 1, 0, 5, 5], [0, 0, 5, 1, 5, 0, 0], [0, 0, 0, 0, 5, 0, 0]]
到目前为止，一切都很好 - 当我运行我的 populateNodeTable 函数和我的网络函数时，我得到了这个输出：
> The previous node is -1
The distance from source is 1000000 # happens 7 times#
>
另外，这很好 - 除了上述函数之外，我在执行我的nearestNeighbour 函数后的输出是：
[0, 1, 2, 3, 4, 5, 6]
这个输出是错误的，是我的问题开始的地方
此外，当我运行包括 tentativeDistance 在内的所有代码时，我收到此错误：
> for nodeIndex in nearestNeighbour:
TypeError: 'function' object is not iterable
我为这篇文章冗长而道歉，我只是对我无法掌握似乎是基本功能的东西感到沮丧