new_contents: #!/usr/bin/env python
  import vtk
  
  def main():
      g = vtk.vtkMutableUndirectedGraph()
      
      v1 = g.AddVertex()
      v2 = g.AddVertex()
      
      g.AddEdge ( v1, v2 )
      print ('Number of vertices:', g.GetNumberOfVertices())
      print ("Number of edges:", g.GetNumberOfEdges())
         
      g.AddEdge ( v1, v2 )
      print ('Number of vertices:', g.GetNumberOfVertices())
      print ('Number of edges:', g.GetNumberOfEdges())
      graphLayoutView = vtk.vtkGraphLayoutView()
      graphLayoutView.AddRepresentationFromInput(g)
      graphLayoutView.ResetCamera()
      graphLayoutView.Render()
      graphLayoutView.GetInteractor().Start()
  
  if __name__ == '__main__':
      main()
  
subject: Create ConstructGraph.py