from vtk import *

reader1 = vtkXMLTreeReader()
reader1.SetFileName("treetest.xml")
reader1.Update()

dummy = vtkTreeMapView()
view = vtkTreeMapView()
view.SetAreaSizeArrayName("size")
view.SetAreaColorArrayName("level")
view.SetAreaLabelArrayName("name")
view.SetAreaLabelVisibility(True)
view.SetAreaHoverArrayName("name")
view.SetLayoutStrategyToSquarify()
view.SetRepresentationFromInput(reader1.GetOutput())

# Apply a theme to the views
theme = vtkViewTheme.CreateMellowTheme()
view.ApplyViewTheme(theme)
theme.FastDelete()

win = vtkRenderWindow()
dummy.SetupRenderWindow(win)
view.SetupRenderWindow(win)
view.Update()
view.GetRenderer().ResetCamera()

win.GetInteractor().Initialize()
win.GetInteractor().Start()