code: def pointz(self, x, y, z=0, m=None):
          
          shapeType = POINTZ
          pointShape = Shape(shapeType)
          pointShape.points.append([x, y, z, m])
          self.shape(pointShape)
docs: Creates a POINTZ shape.
          If the z (elevation) value is not set, it defaults to 0.
          If the m (measure) value is not set, it defaults to NoData.