src/codewars/kata_cipher_helper.py

@@ -4,15 +4,39 @@ class VigenereCipher(object):
         self.alphabet = alphabet
 
     def encode(self, text):
-        idx_key = [self.alphabet.index(x) for x in self.key]
+        encoded = []
-        idx_text = [self.alphabet.index(x) for x in text]
+        idx_key = 0
-        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])
+        for char in text:
+            if char in self.alphabet:
+                text_pos = self.alphabet.index(char)
+                key_char = self.key[idx_key % len(self.key)]
+                key_pos = self.alphabet.index(key_char)
+
+                pos = (text_pos + key_pos) % len(self.alphabet)
+                encoded.append(self.alphabet[pos])
+
+                idx_key += 1
+            else:
+                encoded.append(char)
+
+        return "".join(encoded)
 
     def decode(self, text):
-        pass
+        decoded = []
+        idx_key = 0
 
+        for char in text:
+            if char in self.alphabet:
+                text_pos = self.alphabet.index(char)
+                key_char = self.key[idx_key % len(self.key)]
+                key_pos = self.alphabet.index(key_char)
 
-test = VigenereCipher("password", "abcdefghijklmnopqrstuvwxyz")
+                pos = (text_pos - key_pos) % len(self.alphabet)
+                decoded.append(self.alphabet[pos])
 
-print(test.encode("codewars"))
+                idx_key += 1
+            else:
+                decoded.append(char)
+
+        return "".join(decoded)