python:对graph新的copy方法

gistfile1.py

class Node():
    index = 0
  	neighbors = []
	def __init__ (self, arg) :
		self.index = arg

	def description(self):
		out = []
		out.append (self.index)
		for item in self.neighbors:
			out.append(item.index)
		print (out)

	def allNode (self, checkArray, out) :
		tempNodesArray = self.neighbors[:]
		tempNodesArray.append(self)
		for node in tempNodesArray:
			if node in checkArray:
				pass
			else:
				checkArray.append(node)
				if node in out:
					pass
				else:
					out.append(node)
				node.allNode(checkArray, out)
	def copy(self):
		queue = [self]
		copyNode = Node(self.index)
		nodesMap = {self:copyNode}

		while len(queue) > 0:
			node = queue.pop()
			copyedNode = nodesMap[node]
			for subNode in node.neighbors :
				if subNode in nodesMap :
					copyedNode.neighbors.append(nodesMap[subNode])
				else:
					copyingNode = Node(subNode.index)
					copyedNode.neighbors.append(copyingNode) 				
					#last step will make copyingNode also has neighbors conetents , don't know why
					copyingNode.neighbors = [] 
					nodesMap[subNode] = copyingNode
					queue.append(subNode)
			copyedNode.description()
		return copyNode

		
#create nodes in graph
nodes = []
for i in range (0, 7) :
	node = Node(i)
	nodes.append(node)
 
#create relation ships among all nodes
for node in nodes:
	tempNodesArray = nodes[:]
	tempNodesArray.remove(node)
	node.neighbors = tempNodesArray
 
print("old graph")
for node in nodes:
	node.description()

print("new graph")
newnode = nodes[0].copy()