text: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  
  from runner.koan import *
  
  
  class AboutSets(Koan):
      def test_sets_make_keep_lists_unique(self):
          highlanders = ['MacLeod', 'Ramirez', 'MacLeod', 'Matunas',
              'MacLeod', 'Malcolm', 'MacLeod']
  
          there_can_only_be_only_one = set(highlanders)
  
          self.assertEqual({'MacLeod', 'Ramirez', 'Matunas',
              'Malcolm'}, there_can_only_be_only_one)
  
      def test_sets_are_unordered(self):
          self.assertEqual(set(['1', '2', '3', '4', '5']), set('12345'))
  
      def test_convert_the_set_into_a_list_to_sort_it(self):
          self.assertEqual(['1', '2', '3', '4', '5'], sorted(set('13245')))
  
      # ------------------------------------------------------------------
  
      def test_set_have_arithmetic_operators(self):
          scotsmen = set(['MacLeod', 'Wallace', 'Willie'])
          warriors = set(['MacLeod', 'Wallace', 'Leonidas'])
  
          self.assertEqual({'Willie'}, scotsmen - warriors)
          self.assertEqual({'Leonidas', 'MacLeod', 'Wallace', 'Willie'}, scotsmen | warriors)
          self.assertEqual({'MacLeod', 'Wallace'}, scotsmen & warriors)
          self.assertEqual({'Leonidas', 'Willie'}, scotsmen ^ warriors)
  
      # ------------------------------------------------------------------
  
      def test_we_can_query_set_membership(self):
          self.assertEqual(True, 127 in set([127, 0, 0, 1]))
          self.assertEqual(True, 'cow' not in set('apocalypse now'))
  
      def test_we_can_compare_subsets(self):
          self.assertEqual(True, set('cake') <= set('cherry cake'))
          self.assertEqual(True, set('cake').issubset(set('cherry cake')))
  
          self.assertEqual(False, set('cake') > set('pie'))
  