New comprehention koans, moved one example from about_iteration

johnistan · johnistan · commit aa2fc207c406 · 2013-08-15T15:34:47.000-06:00
diff --git a/python3/koans/about_comprehension.py b/python3/koans/about_comprehension.py
@@ -0,0 +1,60 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+from runner.koan import *
+
+
+class AboutComprehension(Koan):
+
+
+    def test_creating_lists_with_list_comprehensions(self):
+        feast = ['lambs', 'sloths', 'orangutans', 'breakfast cereals',
+            'fruit bats']
+
+        comprehension = [delicacy.capitalize() for delicacy in feast]
+
+        #self.assertEqual(__, comprehension[0])
+        #self.assertEqual(__, comprehension[2])
+
+    def test_filtering_lists_with_list_comprehensions(self):
+        feast = ['spam', 'sloths', 'orangutans', 'breakfast cereals',
+            'fruit bats']
+
+        comprehension = [delicacy for delicacy in feast if len(delicacy) > 6]
+
+        self.assertEqual(__, len(feast))
+        self.assertEqual(__, len(comprehension))
+
+    def test_unpacking_tuples_in_list_comprehensions(self):
+        list_of_tuples = [(1, 'lumberjack'), (2, 'inquisition'), (4, 'spam')]
+        comprehension = [ skit * number for number, skit in list_of_tuples ]
+
+        self.assertEqual(__, comprehension[0])
+        self.assertEqual(__, len(comprehension[2]))
+
+    def test_double_list_comprehention(self):
+        list_of_eggs = ['poached egg', 'fried egg']
+        list_of_meats = ['lite spam', 'ham spam', 'fried spam']
+
+
+        comprehension = [ '{0} and {1}'.format(egg, meat) for egg in list_of_eggs for meat in list_of_meats]
+
+
+        self.assertEqual(__, len(comprehension))
+        self.assertEqual(__, comprehension[0])
+
+    def test_creating_a_set_with_set_comprehention(self):
+        comprehension = { x for x in 'aabbbcccc'}
+
+        self.assertequal(__, len(comprehension))  # remeber that set members are unique
+
+    def test_creating_a_dictionary_with_dictionary_comprehention(self):
+        dict_of_weapons = {'first': 'fear', 'second': 'surprise',
+                           'third':'ruthless efficiency', 'forth':'fanatical devotion', 'fifth': None}
+
+        dict_comprehention = { k.upper(): weapon for k, weapon in dict_of_weapons.iteritems() if weapon}
+
+        self.assertEqual(__, 'first' in dict_comprehention)
+        self.assertEqual(__, 'FIRST' in dict_comprehention)
+        self.assertEqual(__, len(dict_of_weapons))
+        self.assertEqual(__, len(dict_comprehention))
