src/codewars/kata_cipher_helper.py

@@ -1,9 +1,18 @@
 class VigenereCipher(object):
     def __init__(self, key, alphabet):
-        pass
+        self.key = key
+        self.alphabet = alphabet
 
     def encode(self, text):
-        pass
+        idx_key = [self.alphabet.index(x) for x in self.key]
+        idx_text = [self.alphabet.index(x) for x in text]
+        pos_enc = [sum(x) % len(self.alphabet) for x in zip(idx_key, idx_text)]
+        return "".join([self.alphabet[x] for x in pos_enc])
 
     def decode(self, text):
         pass
+
+
+test = VigenereCipher("password", "abcdefghijklmnopqrstuvwxyz")
+
+print(test.encode("codewars"))

tests/codewars/test_cipher_helper.py

@@ -1,5 +1,16 @@
-"""from src.codewars.kata_cipher_helper import *
+from src.codewars.kata_cipher_helper import VigenereCipher
 
 
 def test_cipher_helper():
-    pass"""
+    abc = "abcdefghijklmnopqrstuvwxyz"
+    key = "password"
+    c = VigenereCipher(key, abc)
+
+    assert c.encode("codewars") == "rovwsoiv"
+    assert c.decode("rovwsoiv") == "codewars"
+
+    assert c.encode("waffles") == "laxxhsj"
+    assert c.decode("laxxhsj") == "waffles"
+
+    assert c.encode("CODEWARS") == "CODEWARS"
+    assert c.decode("CODEWARS") == "CODEWARS"