Python : Graph Implementation

class Vertex:
   
    def __init__(self,node):
        self.id = node
        self.adjacent = {}
        self.distance = 99999
        self.visited = False
        self.previous = None
   
    def addNeighbour(self,neighbour,weight = 0):
        self.adjacent[neighbour] = weight
   
    def getConnections(self):
        return self.adjacent.keys()
       
    def getVertexID(self):
        return self.id
   
    def getWeight(self,neighbour):
        return self.adjacent[neighbour]
       
    def setDistance(self,dist):
        self.distance = dist
   
    def getDistance(self):
        return self.distance
       
    def setPrevious(self,prev):
        self.previous = prev
       
    def setVisited(self):
        self.visited = True
       
    def __str__(self):
        return str(self.id) + 'adjacent:' + str([x.id for x in self.adjacent])

class Graph:
    def __init__(self):
        self.vertDictionary = {}
        self.numVertices = 0
       
    def __iter__(self):
        return iter(self.vertDictionary.values())
       
    def addVertex(self,node):
        self.numVertices = self.numVertices + 1
        newVertex = Vertex(node)
        self.vertDictionary[node] = newVertex
        return newVertex
   
    def getVertex(self,n):
        if n in self.vertDictionary:
            return self.vertDictionary[n]
        else:
            return None
   
    def addEdge(self,frm,to,cost =0):
        if frm not in self.vertDictionary:
            self.addVertex(frm)
        if to not in self.vertDictionary:
            self.addVertex(to)
   
        self.vertDictionary[frm].addNeighbour(self.vertDictionary[to],cost)
        self.vertDictionary[to].addNeighbour(self.vertDictionary[frm],cost)
       
    def getVertices(self):
        return self.vertDictionary.keys()
       
    def setPrevious(self,current):
        self.previous = current
   
    def getPrevious(self,current):
        return self.previous
       
    def getEdges(self):
        edges = []
        for v in G:
            for w in v.getConnections():
                vid = v.getVertexID()
                wid = w.getVertexID()
                edges.append((vid,wid,v.getWeight(w)))
        return edges

if __name__ == '__main__':
    G = Graph()
    G.addVertex('a')
    G.addVertex('b')
    G.addVertex('c')
    G.addVertex('d')
    G.addVertex('e')
    G.addEdge('a','b',4)
    G.addEdge('a','c',1)    
    G.addEdge('c','b',2)
    G.addEdge('b','e',4)   
    G.addEdge('c','d',4)   
    G.addEdge('d','e',4)
    print'graph Data'
    print G.getEdges()