resolved doctest

Author: alisatwat3

ciphers/a1z26.py

@@ -14,6 +14,8 @@ def encode(plain: str) -> list[int]:
     >>> encode("myname")
     [13, 25, 14, 1, 13, 5]
     >>> encode("ABCD")
+    Traceback (most recent call last):
+        ...
     ValueError: plain must contain only lowercase letters (a-z)
     """
     if not plain.islower() or not plain.isalpha():