old_contents: # -*- coding: utf-8 -*-
  #
  
  
  class LineLoop(object):
      _ID = 0
  
      def __init__(self, lines):
          self.lines = lines
  
          self.id = 'll{}'.format(LineLoop._ID)
          LineLoop._ID += 1
  
          self.code = '\n'.join([
              '{} = newll;'.format(self.id),
              'Line Loop({}) = {{{}}};'.format(
                  self.id, ', '.join([l.id for l in lines])
              )])
          return
  
new_contents: # -*- coding: utf-8 -*-
  #
  
  
  class LineLoop(object):
      _ID = 0
  
      def __init__(self, lines):
          self.lines = lines
  
          self.id = 'll{}'.format(LineLoop._ID)
          LineLoop._ID += 1
  
          self.code = '\n'.join([
              '{} = newll;'.format(self.id),
              'Line Loop({}) = {{{}}};'.format(
                  self.id, ', '.join([l.id for l in lines])
              )])
          return
  
      def __len__(self):
          return len(self.lines)
  
subject: add __len__