Python的 - 传递函数参数

Question

我如何从一个函数摸出我如何传递参数，这样我可以在另一个函数填充列表挣扎 - 我的代码是：

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 

    currentNode = startNode 

if __name__ == "__main__": 
    nodeTable = populateNodeTable() 
    theNetwork = network() 
    nearestNeighbour(currentNode, theNetwork) 

所以，我想使用距离其他节点最近的节点列表填充最近的邻近函数中的最近的邻近列表。现在，所有其他函数都可以正常工作，并且所有参数都按照它的原样传递。 然而，我nearestNeighbour函数抛出了此错误消息：

if node != 0 and theNetwork[currentNode].visited == false: AttributeError: 'list' object has no attribute 'visited'

（道歉布局，还没有完全领悟了使用该代码的报价还）

Answer 1

class Node(object): 
    def __init__(self, me, dists): 
     super(Node,self).__init__() 
     self.me = me 
     self.dists = dists 
     _inf = Network.INF 
     self.neighbors = sorted((i for i,dist in enumerate(self.dists) if i!=me and dist!=_inf), key=dists.__getitem__) 
     self.clear() 

    def clear(self): 
     self.dist = None 
     self.prev = None 

    def nearestNeighbor(self): 
     try: 
      return self.neighbors[0] 
     except IndexError: 
      return None 

    def __str__(self): 
     return "{0}: {1}".format(self.me, self.dists) 

class Network(object): 
    INF  = 10**6 

    @classmethod 
    def fromFile(cls, fname, delim=None): 
     with open(fname) as inf: 
      return cls([[int(dist) for dist in line.split(delim)] for line in inf]) 

    def __init__(self, distArray): 
     super(Network,self).__init__() 
     self.nodes = [Node(me,dists) for me,dists in enumerate(distArray)] 

    def __str__(self): 
     return '\n'.join(self.nodes) 

    def floodFill(self, fromNode): 
     _nodes = self.nodes 
     for n in _nodes: 
      n.clear() 
     _nodes[fromNode].dist = 0 
     # left as an exercise ;-) 

    def distances(self): 
     return [n.dist for n in self.nodes] 

def main(): 
    nw = Network.fromFile('network.txt', delim=',') 
    print(nw) 

    nw.floodFill(fromNode=0) 
    print(nw.distances()) 

if __name__=="__main__": 
    main() 

Answer 2

这是因为theNetwork[currentNode]返回一个列表。换句话说：theNetwork是列表的列表。

这是它是做这一行：

theNetwork = [[int(node) for node in line.split(',')] for line in f.readlines()] 

Answer 3

theNetwork = [[int(node) for node in line.split(',')] for line in f.readlines()] 

theNetwork是列表的列表。列表（theNetwork[currentNode]）没有visited属性。

也许你打算是这样的：

for line in f.readlines(): 
    theNetwork.extend((int(node) for node in line.split(',')))