Rotational Cipher: Exercise Added

config.json

@@ -101,6 +101,15 @@
       "topics": [
       ]
     },
+    {
+      "slug": "rotational-cipher",
+      "difficulty": 1,
+      "topics": [
+         "strings",
+         "logic",
+         "control-flow (loops)"
+      ]
+    },
     {
       "slug": "difference-of-squares",
       "difficulty": 1,

exercises/rotational-cipher/example.py

@@ -0,0 +1,14 @@
+from string import ascii_lowercase as alpha_lower
+from string import ascii_uppercase as alpha_upper
+ALPHA_LEN = len(alpha_lower)
+
+
+def rotate(message, key):
+    coded_message = ""
+    for char in message:
+        if char in alpha_lower:
+            char = alpha_lower[(alpha_lower.index(char) + key) % ALPHA_LEN]
+        elif char in alpha_upper:
+            char = alpha_upper[(alpha_upper.index(char) + key) % ALPHA_LEN]
+        coded_message += char
+    return coded_message

exercises/rotational-cipher/rotational_cipher.py

@@ -0,0 +1,2 @@
+def rotate():
+    pass

exercises/rotational-cipher/rotational_cipher_test.py

@@ -0,0 +1,53 @@
+import unittest
+
+import rotational_cipher
+
+
+class RotationalCipher(unittest.TestCase):
+    def test_rotate_a_by_1(self):
+        self.assertEqual(rotational_cipher.rotate('a', 1), 'b')
+
+    def test_rotate_a_by_26(self):
+        self.assertEqual(rotational_cipher.rotate('a', 26), 'a')
+
+    def test_rotate_a_by_0(self):
+        self.assertEqual(rotational_cipher.rotate('a', 0), 'a')
+
+    def test_rotate_m_by_13(self):
+        self.assertEqual(rotational_cipher.rotate('m', 13), 'z')
+
+    def test_rotate_n_by_13_with_wrap_around_alphabet(self):
+        self.assertEqual(rotational_cipher.rotate('n', 13), 'a')
+
+    def test_rotate_capital_letters(self):
+        self.assertEqual(rotational_cipher.rotate('OMG', 5), 'TRL')
+
+    def test_rotate_spaces(self):
+        self.assertEqual(rotational_cipher.rotate('O M G', 5),
+                         'T R L')
+
+    def test_rotate_numbers(self):
+        self.assertEqual(
+            rotational_cipher.rotate(
+                                     'Testing 1 2 3 testing',
+                                     4),
+            'Xiwxmrk 1 2 3 xiwxmrk')
+
+    def test_rotate_punctuation(self):
+        self.assertEqual(
+            rotational_cipher.rotate(
+                                     "Let's eat, Grandma!",
+                                     21),
+            "Gzo'n zvo, Bmviyhv!")
+
+    def test_rotate_all_letters(self):
+        self.assertEqual(
+            rotational_cipher.rotate(
+                                     "The quick brown fox jumps"
+                                     " over the lazy dog.",
+                                     13),
+            "Gur dhvpx oebja sbk whzcf bire gur ynml qbt.")
+
+
+if __name__ == '__main__':
+    unittest.main()

exercises/say/say_test.py

@@ -3,7 +3,12 @@
 from say import say
 
 
+# test cases adapted from `x-common//canonical-data.json` @ version: 1.0.0
+
 class SayTest(unittest.TestCase):
+    def test_zero(self):
+        self.assertEqual(say(0), "zero")
+
     def test_one(self):
         self.assertEqual(say(1), "one")
 
@@ -19,6 +24,7 @@ def test_twenty_two(self):
     def test_one_hundred(self):
         self.assertEqual(say(100), "one hundred")
 
+    # additional track specific test
     def test_one_hundred_twenty(self):
         self.assertEqual(say(120), "one hundred and twenty")
 
@@ -31,12 +37,14 @@ def test_one_thousand(self):
     def test_one_thousand_two_hundred_thirty_four(self):
         self.assertEqual(say(1234), "one thousand two hundred and thirty-four")
 
+    # additional track specific test
     def test_eight_hundred_and_ten_thousand(self):
         self.assertEqual(say(810000), "eight hundred and ten thousand")
 
     def test_one_million(self):
         self.assertEqual(say(1e6), "one million")
 
+    # additional track specific test
     def test_one_million_two(self):
         self.assertEqual(say(1000002), "one million and two")
 
@@ -48,24 +56,21 @@ def test_1002345(self):
     def test_one_billion(self):
         self.assertEqual(say(1e9), "one billion")
 
-    def test_number_to_large(self):
-        with self.assertRaises(AttributeError):
-            say(1e12)
-
-    def test_number_negative(self):
-        with self.assertRaises(AttributeError):
-            say(-42)
-
-    def test_zero(self):
-        self.assertEqual(say(0), "zero")
-
     def test_987654321123(self):
         self.assertEqual(
             say(987654321123), ("nine hundred and eighty-seven billion "
                                 "six hundred and fifty-four million "
                                 "three hundred and twenty-one thousand "
                                 "one hundred and twenty-three"))
 
+    def test_number_to_large(self):
+        with self.assertRaises(AttributeError):
+            say(1e12)
+
+    def test_number_negative(self):
+        with self.assertRaises(AttributeError):
+            say(-1)
+
 
 if __name__ == '__main__':
     unittest.main()