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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def Earth(pos=(0, 0, 0), r=1, lw=1):
 """Build a textured actor representing the Earth. .. hint:: |geodesic| |geodesic.py|_ """

    import os

    tss = vtk.vtkTexturedSphereSource()
    tss.SetRadius(r)
    tss.SetThetaResolution(72)
    tss.SetPhiResolution(36)
    earthMapper = vtk.vtkPolyDataMapper()
    earthMapper.SetInputConnection(tss.GetOutputPort())
    earthActor = Actor(c="w")
    earthActor.SetMapper(earthMapper)
    atext = vtk.vtkTexture()
    pnmReader = vtk.vtkPNMReader()
    cdir = os.path.dirname(__file__)
    if cdir == "":
        cdir = "."
    fn = settings.textures_path + "earth.ppm"
    pnmReader.SetFileName(fn)
    atext.SetInputConnection(pnmReader.GetOutputPort())
    atext.InterpolateOn()
    earthActor.SetTexture(atext)
    if not lw:
        earthActor.SetPosition(pos)
        return earthActor
    es = vtk.vtkEarthSource()
    es.SetRadius(r / 0.995)
    earth2Mapper = vtk.vtkPolyDataMapper()
    earth2Mapper.SetInputConnection(es.GetOutputPort())
    earth2Actor = Actor()  # vtk.vtkActor()
    earth2Actor.SetMapper(earth2Mapper)
    earth2Mapper.ScalarVisibilityOff()
    earth2Actor.GetProperty().SetLineWidth(lw)
    ass = Assembly([earthActor, earth2Actor])
    ass.SetPosition(pos)
    settings.collectable_actors.append(ass)
    return ass