code: def copy(self):
          
          chart = Chart.__new__(Chart)
          chart.date = self.date
          chart.pos = self.pos
          chart.hsys = self.hsys
          chart.objects = self.objects.copy()
          chart.houses = self.houses.copy()
          chart.angles = self.angles.copy()
          return chart
docs: Returns a deep copy of this chart.