when I run my program I am getting an error: %run "C:/Users/******/Desktop/KB2.py"

#Creates graph
def loadGraphFile(file):
    graph = []
    for line in file:
        contents = line.split()
        movieName = contents[0]
        actorNames = [contents[i]+ " " + contents[i+1] for i in range(1, len(contents), 2)]        
        movieNode = findNode(graph, movieName)
        if movieNode == None:
            movieNode = mkNode(movieName)
            graph.append(movieNode)
        for actorName in actorNames:            
            actorNode = findNode(graph,actorName)
        if actorNode == None:
            actorNode = mkNode(actorName)
            graph.append(actorNode)
        actorNode.neighbor.append(movieNode)
        movieNode.neighbor.append(actorNode)
        return graph
        
def loadGraphFileName(file = 'file.txt'):
    return loadGraphFile(open(file))