code: def save(self, filename):
          '''save fence points to a file'''
          f = open(filename, mode='w')
          for p in self.points:
              f.write("%f\t%f\n" % (p.lat, p.lng))
          f.close(f save(self, filename):
          '''save fence points to a file'''
          f = open(filename, mode='w')
          for p in self.points:
              f.write("%f\t%f\n" % (p.lat, p.lng))
          f.close()
docs: save fence points to a file