improved readability, error handling; added docstring

ciphers/baconian_cipher.py

@@ -1,89 +1,91 @@
 """
-Program to encode and decode Baconian or Bacon's Cipher
-Wikipedia reference : https://en.wikipedia.org/wiki/Bacon%27s_cipher
+Program to encode and decode using Baconian (Bacon's) Cipher.
+Wikipedia reference: https://en.wikipedia.org/wiki/Bacon%27s_cipher
 """
 
+# Dictionary for encoding letters into Baconian cipher
 encode_dict = {
-    "a": "AAAAA",
-    "b": "AAAAB",
-    "c": "AAABA",
-    "d": "AAABB",
-    "e": "AABAA",
-    "f": "AABAB",
-    "g": "AABBA",
-    "h": "AABBB",
-    "i": "ABAAA",
-    "j": "BBBAA",
-    "k": "ABAAB",
-    "l": "ABABA",
-    "m": "ABABB",
-    "n": "ABBAA",
-    "o": "ABBAB",
-    "p": "ABBBA",
-    "q": "ABBBB",
-    "r": "BAAAA",
-    "s": "BAAAB",
-    "t": "BAABA",
-    "u": "BAABB",
-    "v": "BBBAB",
-    "w": "BABAA",
-    "x": "BABAB",
-    "y": "BABBA",
-    "z": "BABBB",
-    " ": " ",
+    "a": "AAAAA", "b": "AAAAB", "c": "AAABA", "d": "AAABB", "e": "AABAA",
+    "f": "AABAB", "g": "AABBA", "h": "AABBB", "i": "ABAAA", "j": "BBBAA",
+    "k": "ABAAB", "l": "ABABA", "m": "ABABB", "n": "ABBAA", "o": "ABBAB",
+    "p": "ABBBA", "q": "ABBBB", "r": "BAAAA", "s": "BAAAB", "t": "BAABA",
+    "u": "BAABB", "v": "BBBAB", "w": "BABAA", "x": "BABAB", "y": "BABBA",
+    "z": "BABBB", " ": " "
 }
 
-
+# Reverse dictionary for decoding Baconian cipher back into letters
 decode_dict = {value: key for key, value in encode_dict.items()}
 
-
 def encode(word: str) -> str:
     """
-    Encodes to Baconian cipher
+    Encodes a given word into Baconian cipher.
+
+    Only letters of the alphabet and spaces are accepted. Any other characters will raise a ValueError.
+
+    Args:
+        word (str): The word or phrase to encode.
+
+    Returns:
+        str: The encoded message in Baconian cipher.
+
+    Raises:
+        ValueError: If the input contains characters other than letters and spaces.
 
-    >>> encode("hello")
-    'AABBBAABAAABABAABABAABBAB'
-    >>> encode("hello world")
-    'AABBBAABAAABABAABABAABBAB BABAAABBABBAAAAABABAAAABB'
-    >>> encode("hello world!")
-    Traceback (most recent call last):
-        ...
-    Exception: encode() accepts only letters of the alphabet and spaces
+    Examples:
+        >>> encode("hello")
+        'AABBBAABAAABABAABABAABBAB'
+        >>> encode("hello world")
+        'AABBBAABAAABABAABABAABBAB BABAAABBABBAAAAABABAAAABB'
+        >>> encode("hello world!")
+        Traceback (most recent call last):
+            ...
+        ValueError: encode() accepts only letters of the alphabet and spaces
     """
-    encoded = ""
+    encoded = []
     for letter in word.lower():
-        if letter.isalpha() or letter == " ":
-            encoded += encode_dict[letter]
+        if letter in encode_dict:
+            encoded.append(encode_dict[letter])
         else:
-            raise Exception("encode() accepts only letters of the alphabet and spaces")
-    return encoded
-
+            raise ValueError("encode() accepts only letters of the alphabet and spaces")
+    return ''.join(encoded)
 
 def decode(coded: str) -> str:
     """
-    Decodes from Baconian cipher
+    Decodes a Baconian cipher message back into plain text.
+
+    The message must contain only 'A', 'B', and spaces. Other characters will raise a ValueError.
+
+    Args:
+        coded (str): The encoded message to decode.
+
+    Returns:
+        str: The decoded plain text message.
+
+    Raises:
+        ValueError: If the input contains characters other than 'A', 'B', and spaces.
 
-    >>> decode("AABBBAABAAABABAABABAABBAB BABAAABBABBAAAAABABAAAABB")
-    'hello world'
-    >>> decode("AABBBAABAAABABAABABAABBAB")
-    'hello'
-    >>> decode("AABBBAABAAABABAABABAABBAB BABAAABBABBAAAAABABAAAABB!")
-    Traceback (most recent call last):
-        ...
-    Exception: decode() accepts only 'A', 'B' and spaces
+    Examples:
+        >>> decode("AABBBAABAAABABAABABAABBAB BABAAABBABBAAAAABABAAAABB")
+        'hello world'
+        >>> decode("AABBBAABAAABABAABABAABBAB")
+        'hello'
+        >>> decode("AABBBAABAAABABAABABAABBAB BABAAABBABBAAAAABABAAAABB!")
+        Traceback (most recent call last):
+            ...
+        ValueError: decode() accepts only 'A', 'B' and spaces
     """
-    if set(coded) - {"A", "B", " "} != set():
-        raise Exception("decode() accepts only 'A', 'B' and spaces")
-    decoded = ""
+    if set(coded) - {"A", "B", " "}:
+        raise ValueError("decode() accepts only 'A', 'B' and spaces")
+
+    decoded = []
     for word in coded.split():
-        while len(word) != 0:
-            decoded += decode_dict[word[:5]]
-            word = word[5:]
-        decoded += " "
-    return decoded.strip()
-
+        for i in range(0, len(word), 5):
+            chunk = word[i:i+5]
+            decoded.append(decode_dict.get(chunk, ''))
+        decoded.append(' ')  # Add space between words
+
+    return ''.join(decoded).strip()
 
 if __name__ == "__main__":
     from doctest import testmod
-
     testmod()