Add docstrings and doctests and fix a bug ciphers/trifid_cipher.py

ciphers/trifid_cipher.py

@@ -1,15 +1,35 @@
-# https://en.wikipedia.org/wiki/Trifid_cipher
+"""
+The trifid cipher uses a table to fractionate each plaintext letter into a trigram,
+mixes the constituents of the trigrams, and then applies the table in reverse to turn
+these mixed trigrams into ciphertext letters.
+
+https://en.wikipedia.org/wiki/Trifid_cipher
+"""
+
 from __future__ import annotations
 
+# fmt: off
+TEST_CHARACTER_TO_NUMBER = {
+ "A": "111", "B": "112", "C": "113", "D": "121", "E": "122", "F": "123", "G": "131",
+ "H": "132", "I": "133", "J": "211", "K": "212", "L": "213", "M": "221", "N": "222",
+ "O": "223", "P": "231", "Q": "232", "R": "233", "S": "311", "T": "312", "U": "313",
+ "V": "321", "W": "322", "X": "323", "Y": "331", "Z": "332", "+": "333",
+}
+# fmt: off
 
-def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> str:
- one, two, three = "", "", ""
- tmp = []
+TEST_NUMBER_TO_CHARACTER = {val: key for key, val in TEST_CHARACTER_TO_NUMBER.items()}
 
- for character in message_part:
- tmp.append(character_to_number[character])
 
- for each in tmp:
+def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> str:
+ """
+ Arrange the triagram value of each letter of 'message_part' vertically and join
+ them horizontally.
+
+ >>> __encrypt_part('ASK', TEST_CHARACTER_TO_NUMBER)
+ '132111112'
+ """
+ one, two, three = "", "", ""
+ for each in (character_to_number[character] for character in message_part):
  one += each[0]
  two += each[1]
  three += each[2]
@@ -20,12 +40,16 @@ def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> st
 def __decrypt_part(
  message_part: str, character_to_number: dict[str, str]
 ) -> tuple[str, str, str]:
- tmp, this_part = "", ""
+ """
+ Convert each letter of the input string into their respective trigram values, join
+ them and split them into three equal groups of strings which are returned.
+
+ >>> __decrypt_part('ABCDE', TEST_CHARACTER_TO_NUMBER)
+ ('11111', '21131', '21122')
+ """
+ this_part = "".join(character_to_number[character] for character in message_part)
  result = []
-
- for character in message_part:
- this_part += character_to_number[character]
-
+ tmp = ""
  for digit in this_part:
  tmp += digit
  if len(tmp) == len(message_part):
@@ -38,97 +62,148 @@ def __decrypt_part(
 def __prepare(
  message: str, alphabet: str
 ) -> tuple[str, str, dict[str, str], dict[str, str]]:
+ """
+ A helper function that generates the triagrams and assigns each letter of the
+ alphabet to its corresponding triagram and stores this in a dictionary
+ ("character_to_number" and "number_to_character") after confirming if the
+ alphabet's length is 27.
+
+ >>> test = __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVwxYZ+')
+ >>> expected = ('IAMABOY','ABCDEFGHIJKLMNOPQRSTUVWXYZ+',
+ ... TEST_CHARACTER_TO_NUMBER, TEST_NUMBER_TO_CHARACTER)
+ >>> test == expected
+ True
+
+ Testing with incomplete alphabet
+ >>> __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVw')
+ Traceback (most recent call last):
+ ...
+ KeyError: 'Length of alphabet has to be 27.'
+
+ Testing with extra long alphabets
+ >>> __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVwxyzzwwtyyujjgfd')
+ Traceback (most recent call last):
+ ...
+ KeyError: 'Length of alphabet has to be 27.'
+
+ Testing with punctuations that are not in the given alphabet
+ >>> __prepare('am i a boy?','abCdeFghijkLmnopqrStuVwxYZ+')
+ Traceback (most recent call last):
+ ...
+ ValueError: Each message character has to be included in alphabet!
+
+ Testing with numbers
+ >>> __prepare(500,'abCdeFghijkLmnopqrStuVwxYZ+')
+ Traceback (most recent call last):
+ ...
+ AttributeError: 'int' object has no attribute 'replace'
+ """
  # Validate message and alphabet, set to upper and remove spaces
  alphabet = alphabet.replace(" ", "").upper()
  message = message.replace(" ", "").upper()
 
  # Check length and characters
  if len(alphabet) != 27:
  raise KeyError("Length of alphabet has to be 27.")
- for each in message:
- if each not in alphabet:
- raise ValueError("Each message character has to be included in alphabet!")
+ if any(char not in alphabet for char in message):
+ raise ValueError("Each message character has to be included in alphabet!")
 
  # Generate dictionares
- numbers = (
- "111",
- "112",
- "113",
- "121",
- "122",
- "123",
- "131",
- "132",
- "133",
- "211",
- "212",
- "213",
- "221",
- "222",
- "223",
- "231",
- "232",
- "233",
- "311",
- "312",
- "313",
- "321",
- "322",
- "323",
- "331",
- "332",
- "333",
- )
- character_to_number = {}
- number_to_character = {}
- for letter, number in zip(alphabet, numbers):
- character_to_number[letter] = number
- number_to_character[number] = letter
+ character_to_number = dict(zip(alphabet, TEST_CHARACTER_TO_NUMBER.values()))
+ number_to_character = {
+ number: letter for letter, number in character_to_number.items()
+ }
 
  return message, alphabet, character_to_number, number_to_character
 
 
 def encrypt_message(
  message: str, alphabet: str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ.", period: int = 5
 ) -> str:
+ """
+ encrypt_message
+ ===============
+
+ Encrypts a message using the trifid_cipher. Any punctuatuions that
+ would be used should be added to the alphabet.
+
+ PARAMETERS
+ ----------
+
+ * message: The message you want to encrypt.
+ * alphabet (optional): The characters to be used for the cipher .
+ * period (optional): The number of characters you want in a group whilst
+ encrypting.
+
+ >>> encrypt_message('I am a boy')
+ 'BCDGBQY'
+
+ >>> encrypt_message(' ')
+ ''
+
+ >>> encrypt_message(' aide toi le c iel ta id era ',
+ ... 'FELIXMARDSTBCGHJKNOPQUVWYZ+',5)
+ 'FMJFVOISSUFTFPUFEQQC'
+
+ """
  message, alphabet, character_to_number, number_to_character = __prepare(
  message, alphabet
  )
- encrypted, encrypted_numeric = "", ""
 
+ encrypted_numeric = ""
  for i in range(0, len(message) + 1, period):
  encrypted_numeric += __encrypt_part(
  message[i : i + period], character_to_number
  )
 
+ encrypted = ""
  for i in range(0, len(encrypted_numeric), 3):
  encrypted += number_to_character[encrypted_numeric[i : i + 3]]
-
  return encrypted
 
 
 def decrypt_message(
  message: str, alphabet: str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ.", period: int = 5
 ) -> str:
+ """
+ decrypt_message
+ ===============
+
+ Decrypts a trifid_cipher encrypted message .
+
+ PARAMETERS
+ ----------
+
+ * message: The message you want to decrypt .
+ * alphabet (optional): The characters used for the cipher.
+ * period (optional): The number of characters used in grouping when it
+ was encrypted.
+
+ >>> decrypt_message('BCDGBQY')
+ 'IAMABOY'
+
+ Decrypting with your own alphabet and period
+ >>> decrypt_message('FMJFVOISSUFTFPUFEQQC','FELIXMARDSTBCGHJKNOPQUVWYZ+',5)
+ 'AIDETOILECIELTAIDERA'
+ """
  message, alphabet, character_to_number, number_to_character = __prepare(
  message, alphabet
  )
- decrypted_numeric = []
- decrypted = ""
 
- for i in range(0, len(message) + 1, period):
+ decrypted_numeric = []
+ for i in range(0, len(message), period):
  a, b, c = __decrypt_part(message[i : i + period], character_to_number)
 
  for j in range(len(a)):
  decrypted_numeric.append(a[j] + b[j] + c[j])
 
- for each in decrypted_numeric:
- decrypted += number_to_character[each]
-
- return decrypted
+ return "".join(number_to_character[each] for each in decrypted_numeric)
 
 
 if __name__ == "__main__":
+ import doctest
+
+ doctest.testmod()
  msg = "DEFEND THE EAST WALL OF THE CASTLE."
  encrypted = encrypt_message(msg, "EPSDUCVWYM.ZLKXNBTFGORIJHAQ")
  decrypted = decrypt_message(encrypted, "EPSDUCVWYM.ZLKXNBTFGORIJHAQ")

pyproject.toml

@@ -135,5 +135,5 @@ omit = [
 sort = "Cover"
 
 [tool.codespell]
-ignore-words-list = "3rt,ans,crate,damon,fo,followings,hist,iff,kwanza,manuel,mater,secant,som,sur,tim,zar"
+ignore-words-list = "3rt,ans,crate,damon,fo,followings,hist,iff,kwanza,manuel,mater,secant,som,sur,tim,toi,zar"
 skip = "./.*,*.json,ciphers/prehistoric_men.txt,project_euler/problem_022/p022_names.txt,pyproject.toml,strings/dictionary.txt,strings/words.txt"

ciphers/trifid_cipher.py

@@ -1,15 +1,35 @@
-# https://en.wikipedia.org/wiki/Trifid_cipher
+"""
+The trifid cipher uses a table to fractionate each plaintext letter into a trigram,
+mixes the constituents of the trigrams, and then applies the table in reverse to turn
+these mixed trigrams into ciphertext letters.
+
+https://en.wikipedia.org/wiki/Trifid_cipher
+"""
+
 from __future__ import annotations
 
+# fmt: off
+TEST_CHARACTER_TO_NUMBER = {
+ "A": "111", "B": "112", "C": "113", "D": "121", "E": "122", "F": "123", "G": "131",
+ "H": "132", "I": "133", "J": "211", "K": "212", "L": "213", "M": "221", "N": "222",
+ "O": "223", "P": "231", "Q": "232", "R": "233", "S": "311", "T": "312", "U": "313",
+ "V": "321", "W": "322", "X": "323", "Y": "331", "Z": "332", "+": "333",
+}
+# fmt: off
 
-def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> str:
- one, two, three = "", "", ""
- tmp = []
+TEST_NUMBER_TO_CHARACTER = {val: key for key, val in TEST_CHARACTER_TO_NUMBER.items()}
 
- for character in message_part:
- tmp.append(character_to_number[character])
 
- for each in tmp:
+def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> str:
+ """
+ Arrange the triagram value of each letter of 'message_part' vertically and join
+ them horizontally.
+
+ >>> __encrypt_part('ASK', TEST_CHARACTER_TO_NUMBER)
+ '132111112'
+ """
+ one, two, three = "", "", ""
+ for each in (character_to_number[character] for character in message_part):
  one += each[0]
  two += each[1]
  three += each[2]
@@ -20,12 +40,16 @@ def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> st
 def __decrypt_part(
  message_part: str, character_to_number: dict[str, str]
 ) -> tuple[str, str, str]:
- tmp, this_part = "", ""
+ """
+ Convert each letter of the input string into their respective trigram values, join
+ them and split them into three equal groups of strings which are returned.
+
+ >>> __decrypt_part('ABCDE', TEST_CHARACTER_TO_NUMBER)
+ ('11111', '21131', '21122')
+ """
+ this_part = "".join(character_to_number[character] for character in message_part)
  result = []
-
- for character in message_part:
- this_part += character_to_number[character]
-
+ tmp = ""
  for digit in this_part:
  tmp += digit
  if len(tmp) == len(message_part):
@@ -38,97 +62,148 @@ def __decrypt_part(
 def __prepare(
  message: str, alphabet: str
 ) -> tuple[str, str, dict[str, str], dict[str, str]]:
+ """
+ A helper function that generates the triagrams and assigns each letter of the
+ alphabet to its corresponding triagram and stores this in a dictionary
+ ("character_to_number" and "number_to_character") after confirming if the
+ alphabet's length is 27.
+
+ >>> test = __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVwxYZ+')
+ >>> expected = ('IAMABOY','ABCDEFGHIJKLMNOPQRSTUVWXYZ+',
+ ... TEST_CHARACTER_TO_NUMBER, TEST_NUMBER_TO_CHARACTER)
+ >>> test == expected
+ True
+
+ Testing with incomplete alphabet
+ >>> __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVw')
+ Traceback (most recent call last):
+ ...
+ KeyError: 'Length of alphabet has to be 27.'
+
+ Testing with extra long alphabets
+ >>> __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVwxyzzwwtyyujjgfd')
+ Traceback (most recent call last):
+ ...
+ KeyError: 'Length of alphabet has to be 27.'
+
+ Testing with punctuations that are not in the given alphabet
+ >>> __prepare('am i a boy?','abCdeFghijkLmnopqrStuVwxYZ+')
+ Traceback (most recent call last):
+ ...
+ ValueError: Each message character has to be included in alphabet!
+
+ Testing with numbers
+ >>> __prepare(500,'abCdeFghijkLmnopqrStuVwxYZ+')
+ Traceback (most recent call last):
+ ...
+ AttributeError: 'int' object has no attribute 'replace'
+ """
  # Validate message and alphabet, set to upper and remove spaces
  alphabet = alphabet.replace(" ", "").upper()
  message = message.replace(" ", "").upper()
 
  # Check length and characters
  if len(alphabet) != 27:
  raise KeyError("Length of alphabet has to be 27.")
- for each in message:
- if each not in alphabet:
- raise ValueError("Each message character has to be included in alphabet!")
+ if any(char not in alphabet for char in message):
+ raise ValueError("Each message character has to be included in alphabet!")
 
  # Generate dictionares
- numbers = (
- "111",
- "112",
- "113",
- "121",
- "122",
- "123",
- "131",
- "132",
- "133",
- "211",
- "212",
- "213",
- "221",
- "222",
- "223",
- "231",
- "232",
- "233",
- "311",
- "312",
- "313",
- "321",
- "322",
- "323",
- "331",
- "332",
- "333",
- )
- character_to_number = {}
- number_to_character = {}
- for letter, number in zip(alphabet, numbers):
- character_to_number[letter] = number
- number_to_character[number] = letter
+ character_to_number = dict(zip(alphabet, TEST_CHARACTER_TO_NUMBER.values()))
+ number_to_character = {
+ number: letter for letter, number in character_to_number.items()
+ }
 
  return message, alphabet, character_to_number, number_to_character
 
 
 def encrypt_message(
  message: str, alphabet: str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ.", period: int = 5
 ) -> str:
+ """
+ encrypt_message
+ ===============
+
+ Encrypts a message using the trifid_cipher. Any punctuatuions that
+ would be used should be added to the alphabet.
+
+ PARAMETERS
+ ----------
+
+ * message: The message you want to encrypt.
+ * alphabet (optional): The characters to be used for the cipher .
+ * period (optional): The number of characters you want in a group whilst
+ encrypting.
+
+ >>> encrypt_message('I am a boy')
+ 'BCDGBQY'
+
+ >>> encrypt_message(' ')
+ ''
+
+ >>> encrypt_message(' aide toi le c iel ta id era ',
+ ... 'FELIXMARDSTBCGHJKNOPQUVWYZ+',5)
+ 'FMJFVOISSUFTFPUFEQQC'
+
+ """
  message, alphabet, character_to_number, number_to_character = __prepare(
  message, alphabet
  )
- encrypted, encrypted_numeric = "", ""
 
+ encrypted_numeric = ""
  for i in range(0, len(message) + 1, period):
  encrypted_numeric += __encrypt_part(
  message[i : i + period], character_to_number
  )
 
+ encrypted = ""
  for i in range(0, len(encrypted_numeric), 3):
  encrypted += number_to_character[encrypted_numeric[i : i + 3]]
-
  return encrypted
 
 
 def decrypt_message(
  message: str, alphabet: str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ.", period: int = 5
 ) -> str:
+ """
+ decrypt_message
+ ===============
+
+ Decrypts a trifid_cipher encrypted message .
+
+ PARAMETERS
+ ----------
+
+ * message: The message you want to decrypt .
+ * alphabet (optional): The characters used for the cipher.
+ * period (optional): The number of characters used in grouping when it
+ was encrypted.
+
+ >>> decrypt_message('BCDGBQY')
+ 'IAMABOY'
+
+ Decrypting with your own alphabet and period
+ >>> decrypt_message('FMJFVOISSUFTFPUFEQQC','FELIXMARDSTBCGHJKNOPQUVWYZ+',5)
+ 'AIDETOILECIELTAIDERA'
+ """
  message, alphabet, character_to_number, number_to_character = __prepare(
  message, alphabet
  )
- decrypted_numeric = []
- decrypted = ""
 
- for i in range(0, len(message) + 1, period):
+ decrypted_numeric = []
+ for i in range(0, len(message), period):
  a, b, c = __decrypt_part(message[i : i + period], character_to_number)
 
  for j in range(len(a)):
  decrypted_numeric.append(a[j] + b[j] + c[j])
 
- for each in decrypted_numeric:
- decrypted += number_to_character[each]
-
- return decrypted
+ return "".join(number_to_character[each] for each in decrypted_numeric)
 
 
 if __name__ == "__main__":
+ import doctest
+
+ doctest.testmod()
  msg = "DEFEND THE EAST WALL OF THE CASTLE."
  encrypted = encrypt_message(msg, "EPSDUCVWYM.ZLKXNBTFGORIJHAQ")
  decrypted = decrypt_message(encrypted, "EPSDUCVWYM.ZLKXNBTFGORIJHAQ")

pyproject.toml

@@ -135,5 +135,5 @@ omit = [
 sort = "Cover"
 
 [tool.codespell]
-ignore-words-list = "3rt,ans,crate,damon,fo,followings,hist,iff,kwanza,manuel,mater,secant,som,sur,tim,zar"
+ignore-words-list = "3rt,ans,crate,damon,fo,followings,hist,iff,kwanza,manuel,mater,secant,som,sur,tim,toi,zar"
 skip = "./.*,*.json,ciphers/prehistoric_men.txt,project_euler/problem_022/p022_names.txt,pyproject.toml,strings/dictionary.txt,strings/words.txt"

ciphers/trifid_cipher.py

@@ -1,15 +1,35 @@
-# https://en.wikipedia.org/wiki/Trifid_cipher
+"""
+The trifid cipher uses a table to fractionate each plaintext letter into a trigram,
+mixes the constituents of the trigrams, and then applies the table in reverse to turn
+these mixed trigrams into ciphertext letters.
+
+https://en.wikipedia.org/wiki/Trifid_cipher
+"""
+
 from __future__ import annotations
 
+# fmt: off
+TEST_CHARACTER_TO_NUMBER = {
+ "A": "111", "B": "112", "C": "113", "D": "121", "E": "122", "F": "123", "G": "131",
+ "H": "132", "I": "133", "J": "211", "K": "212", "L": "213", "M": "221", "N": "222",
+ "O": "223", "P": "231", "Q": "232", "R": "233", "S": "311", "T": "312", "U": "313",
+ "V": "321", "W": "322", "X": "323", "Y": "331", "Z": "332", "+": "333",
+}
+# fmt: off
 
-def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> str:
- one, two, three = "", "", ""
- tmp = []
+TEST_NUMBER_TO_CHARACTER = {val: key for key, val in TEST_CHARACTER_TO_NUMBER.items()}
 
- for character in message_part:
- tmp.append(character_to_number[character])
 
- for each in tmp:
+def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> str:
+ """
+ Arrange the triagram value of each letter of 'message_part' vertically and join
+ them horizontally.
+
+ >>> __encrypt_part('ASK', TEST_CHARACTER_TO_NUMBER)
+ '132111112'
+ """
+ one, two, three = "", "", ""
+ for each in (character_to_number[character] for character in message_part):
  one += each[0]
  two += each[1]
  three += each[2]
@@ -20,12 +40,16 @@ def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> st
 def __decrypt_part(
  message_part: str, character_to_number: dict[str, str]
 ) -> tuple[str, str, str]:
- tmp, this_part = "", ""
+ """
+ Convert each letter of the input string into their respective trigram values, join
+ them and split them into three equal groups of strings which are returned.
+
+ >>> __decrypt_part('ABCDE', TEST_CHARACTER_TO_NUMBER)
+ ('11111', '21131', '21122')
+ """
+ this_part = "".join(character_to_number[character] for character in message_part)
  result = []
-
- for character in message_part:
- this_part += character_to_number[character]
-
+ tmp = ""
  for digit in this_part:
  tmp += digit
  if len(tmp) == len(message_part):
@@ -38,97 +62,148 @@ def __decrypt_part(
 def __prepare(
  message: str, alphabet: str
 ) -> tuple[str, str, dict[str, str], dict[str, str]]:
+ """
+ A helper function that generates the triagrams and assigns each letter of the
+ alphabet to its corresponding triagram and stores this in a dictionary
+ ("character_to_number" and "number_to_character") after confirming if the
+ alphabet's length is 27.
+
+ >>> test = __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVwxYZ+')
+ >>> expected = ('IAMABOY','ABCDEFGHIJKLMNOPQRSTUVWXYZ+',
+ ... TEST_CHARACTER_TO_NUMBER, TEST_NUMBER_TO_CHARACTER)
+ >>> test == expected
+ True
+
+ Testing with incomplete alphabet
+ >>> __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVw')
+ Traceback (most recent call last):
+ ...
+ KeyError: 'Length of alphabet has to be 27.'
+
+ Testing with extra long alphabets
+ >>> __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVwxyzzwwtyyujjgfd')
+ Traceback (most recent call last):
+ ...
+ KeyError: 'Length of alphabet has to be 27.'
+
+ Testing with punctuations that are not in the given alphabet
+ >>> __prepare('am i a boy?','abCdeFghijkLmnopqrStuVwxYZ+')
+ Traceback (most recent call last):
+ ...
+ ValueError: Each message character has to be included in alphabet!
+
+ Testing with numbers
+ >>> __prepare(500,'abCdeFghijkLmnopqrStuVwxYZ+')
+ Traceback (most recent call last):
+ ...
+ AttributeError: 'int' object has no attribute 'replace'
+ """
  # Validate message and alphabet, set to upper and remove spaces
  alphabet = alphabet.replace(" ", "").upper()
  message = message.replace(" ", "").upper()
 
  # Check length and characters
  if len(alphabet) != 27:
  raise KeyError("Length of alphabet has to be 27.")
- for each in message:
- if each not in alphabet:
- raise ValueError("Each message character has to be included in alphabet!")
+ if any(char not in alphabet for char in message):
+ raise ValueError("Each message character has to be included in alphabet!")
 
  # Generate dictionares
- numbers = (
- "111",
- "112",
- "113",
- "121",
- "122",
- "123",
- "131",
- "132",
- "133",
- "211",
- "212",
- "213",
- "221",
- "222",
- "223",
- "231",
- "232",
- "233",
- "311",
- "312",
- "313",
- "321",
- "322",
- "323",
- "331",
- "332",
- "333",
- )
- character_to_number = {}
- number_to_character = {}
- for letter, number in zip(alphabet, numbers):
- character_to_number[letter] = number
- number_to_character[number] = letter
+ character_to_number = dict(zip(alphabet, TEST_CHARACTER_TO_NUMBER.values()))
+ number_to_character = {
+ number: letter for letter, number in character_to_number.items()
+ }
 
  return message, alphabet, character_to_number, number_to_character
 
 
 def encrypt_message(
  message: str, alphabet: str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ.", period: int = 5
 ) -> str:
+ """
+ encrypt_message
+ ===============
+
+ Encrypts a message using the trifid_cipher. Any punctuatuions that
+ would be used should be added to the alphabet.
+
+ PARAMETERS
+ ----------
+
+ * message: The message you want to encrypt.
+ * alphabet (optional): The characters to be used for the cipher .
+ * period (optional): The number of characters you want in a group whilst
+ encrypting.
+
+ >>> encrypt_message('I am a boy')
+ 'BCDGBQY'
+
+ >>> encrypt_message(' ')
+ ''
+
+ >>> encrypt_message(' aide toi le c iel ta id era ',
+ ... 'FELIXMARDSTBCGHJKNOPQUVWYZ+',5)
+ 'FMJFVOISSUFTFPUFEQQC'
+
+ """
  message, alphabet, character_to_number, number_to_character = __prepare(
  message, alphabet
  )
- encrypted, encrypted_numeric = "", ""
 
+ encrypted_numeric = ""
  for i in range(0, len(message) + 1, period):
  encrypted_numeric += __encrypt_part(
  message[i : i + period], character_to_number
  )
 
+ encrypted = ""
  for i in range(0, len(encrypted_numeric), 3):
  encrypted += number_to_character[encrypted_numeric[i : i + 3]]
-
  return encrypted
 
 
 def decrypt_message(
  message: str, alphabet: str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ.", period: int = 5
 ) -> str:
+ """
+ decrypt_message
+ ===============
+
+ Decrypts a trifid_cipher encrypted message .
+
+ PARAMETERS
+ ----------
+
+ * message: The message you want to decrypt .
+ * alphabet (optional): The characters used for the cipher.
+ * period (optional): The number of characters used in grouping when it
+ was encrypted.
+
+ >>> decrypt_message('BCDGBQY')
+ 'IAMABOY'
+
+ Decrypting with your own alphabet and period
+ >>> decrypt_message('FMJFVOISSUFTFPUFEQQC','FELIXMARDSTBCGHJKNOPQUVWYZ+',5)
+ 'AIDETOILECIELTAIDERA'
+ """
  message, alphabet, character_to_number, number_to_character = __prepare(
  message, alphabet
  )
- decrypted_numeric = []
- decrypted = ""
 
- for i in range(0, len(message) + 1, period):
+ decrypted_numeric = []
+ for i in range(0, len(message), period):
  a, b, c = __decrypt_part(message[i : i + period], character_to_number)
 
  for j in range(len(a)):
  decrypted_numeric.append(a[j] + b[j] + c[j])
 
- for each in decrypted_numeric:
- decrypted += number_to_character[each]
-
- return decrypted
+ return "".join(number_to_character[each] for each in decrypted_numeric)
 
 
 if __name__ == "__main__":
+ import doctest
+
+ doctest.testmod()
  msg = "DEFEND THE EAST WALL OF THE CASTLE."
  encrypted = encrypt_message(msg, "EPSDUCVWYM.ZLKXNBTFGORIJHAQ")
  decrypted = decrypt_message(encrypted, "EPSDUCVWYM.ZLKXNBTFGORIJHAQ")

pyproject.toml

@@ -135,5 +135,5 @@ omit = [
 sort = "Cover"
 
 [tool.codespell]
-ignore-words-list = "3rt,ans,crate,damon,fo,followings,hist,iff,kwanza,manuel,mater,secant,som,sur,tim,zar"
+ignore-words-list = "3rt,ans,crate,damon,fo,followings,hist,iff,kwanza,manuel,mater,secant,som,sur,tim,toi,zar"
 skip = "./.*,*.json,ciphers/prehistoric_men.txt,project_euler/problem_022/p022_names.txt,pyproject.toml,strings/dictionary.txt,strings/words.txt"

ciphers/trifid_cipher.py

@@ -1,15 +1,35 @@
-# https://en.wikipedia.org/wiki/Trifid_cipher
+"""
+The trifid cipher uses a table to fractionate each plaintext letter into a trigram,
+mixes the constituents of the trigrams, and then applies the table in reverse to turn
+these mixed trigrams into ciphertext letters.
+
+https://en.wikipedia.org/wiki/Trifid_cipher
+"""
+
 from __future__ import annotations
 
+# fmt: off
+TEST_CHARACTER_TO_NUMBER = {
+ "A": "111", "B": "112", "C": "113", "D": "121", "E": "122", "F": "123", "G": "131",
+ "H": "132", "I": "133", "J": "211", "K": "212", "L": "213", "M": "221", "N": "222",
+ "O": "223", "P": "231", "Q": "232", "R": "233", "S": "311", "T": "312", "U": "313",
+ "V": "321", "W": "322", "X": "323", "Y": "331", "Z": "332", "+": "333",
+}
+# fmt: off
 
-def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> str:
- one, two, three = "", "", ""
- tmp = []
+TEST_NUMBER_TO_CHARACTER = {val: key for key, val in TEST_CHARACTER_TO_NUMBER.items()}
 
- for character in message_part:
- tmp.append(character_to_number[character])
 
- for each in tmp:
+def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> str:
+ """
+ Arrange the triagram value of each letter of 'message_part' vertically and join
+ them horizontally.
+
+ >>> __encrypt_part('ASK', TEST_CHARACTER_TO_NUMBER)
+ '132111112'
+ """
+ one, two, three = "", "", ""
+ for each in (character_to_number[character] for character in message_part):
  one += each[0]
  two += each[1]
  three += each[2]
@@ -20,12 +40,16 @@ def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> st
 def __decrypt_part(
  message_part: str, character_to_number: dict[str, str]
 ) -> tuple[str, str, str]:
- tmp, this_part = "", ""
+ """
+ Convert each letter of the input string into their respective trigram values, join
+ them and split them into three equal groups of strings which are returned.
+
+ >>> __decrypt_part('ABCDE', TEST_CHARACTER_TO_NUMBER)
+ ('11111', '21131', '21122')
+ """
+ this_part = "".join(character_to_number[character] for character in message_part)
  result = []
-
- for character in message_part:
- this_part += character_to_number[character]
-
+ tmp = ""
  for digit in this_part:
  tmp += digit
  if len(tmp) == len(message_part):
@@ -38,97 +62,148 @@ def __decrypt_part(
 def __prepare(
  message: str, alphabet: str
 ) -> tuple[str, str, dict[str, str], dict[str, str]]:
+ """
+ A helper function that generates the triagrams and assigns each letter of the
+ alphabet to its corresponding triagram and stores this in a dictionary
+ ("character_to_number" and "number_to_character") after confirming if the
+ alphabet's length is 27.
+
+ >>> test = __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVwxYZ+')
+ >>> expected = ('IAMABOY','ABCDEFGHIJKLMNOPQRSTUVWXYZ+',
+ ... TEST_CHARACTER_TO_NUMBER, TEST_NUMBER_TO_CHARACTER)
+ >>> test == expected
+ True
+
+ Testing with incomplete alphabet
+ >>> __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVw')
+ Traceback (most recent call last):
+ ...
+ KeyError: 'Length of alphabet has to be 27.'
+
+ Testing with extra long alphabets
+ >>> __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVwxyzzwwtyyujjgfd')
+ Traceback (most recent call last):
+ ...
+ KeyError: 'Length of alphabet has to be 27.'
+
+ Testing with punctuations that are not in the given alphabet
+ >>> __prepare('am i a boy?','abCdeFghijkLmnopqrStuVwxYZ+')
+ Traceback (most recent call last):
+ ...
+ ValueError: Each message character has to be included in alphabet!
+
+ Testing with numbers
+ >>> __prepare(500,'abCdeFghijkLmnopqrStuVwxYZ+')
+ Traceback (most recent call last):
+ ...
+ AttributeError: 'int' object has no attribute 'replace'
+ """
  # Validate message and alphabet, set to upper and remove spaces
  alphabet = alphabet.replace(" ", "").upper()
  message = message.replace(" ", "").upper()
 
  # Check length and characters
  if len(alphabet) != 27:
  raise KeyError("Length of alphabet has to be 27.")
- for each in message:
- if each not in alphabet:
- raise ValueError("Each message character has to be included in alphabet!")
+ if any(char not in alphabet for char in message):
+ raise ValueError("Each message character has to be included in alphabet!")
 
  # Generate dictionares
- numbers = (
- "111",
- "112",
- "113",
- "121",
- "122",
- "123",
- "131",
- "132",
- "133",
- "211",
- "212",
- "213",
- "221",
- "222",
- "223",
- "231",
- "232",
- "233",
- "311",
- "312",
- "313",
- "321",
- "322",
- "323",
- "331",
- "332",
- "333",
- )
- character_to_number = {}
- number_to_character = {}
- for letter, number in zip(alphabet, numbers):
- character_to_number[letter] = number
- number_to_character[number] = letter
+ character_to_number = dict(zip(alphabet, TEST_CHARACTER_TO_NUMBER.values()))
+ number_to_character = {
+ number: letter for letter, number in character_to_number.items()
+ }
 
  return message, alphabet, character_to_number, number_to_character
 
 
 def encrypt_message(
  message: str, alphabet: str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ.", period: int = 5
 ) -> str:
+ """
+ encrypt_message
+ ===============
+
+ Encrypts a message using the trifid_cipher. Any punctuatuions that
+ would be used should be added to the alphabet.
+
+ PARAMETERS
+ ----------
+
+ * message: The message you want to encrypt.
+ * alphabet (optional): The characters to be used for the cipher .
+ * period (optional): The number of characters you want in a group whilst
+ encrypting.
+
+ >>> encrypt_message('I am a boy')
+ 'BCDGBQY'
+
+ >>> encrypt_message(' ')
+ ''
+
+ >>> encrypt_message(' aide toi le c iel ta id era ',
+ ... 'FELIXMARDSTBCGHJKNOPQUVWYZ+',5)
+ 'FMJFVOISSUFTFPUFEQQC'
+
+ """
  message, alphabet, character_to_number, number_to_character = __prepare(
  message, alphabet
  )
- encrypted, encrypted_numeric = "", ""
 
+ encrypted_numeric = ""
  for i in range(0, len(message) + 1, period):
  encrypted_numeric += __encrypt_part(
  message[i : i + period], character_to_number
  )
 
+ encrypted = ""
  for i in range(0, len(encrypted_numeric), 3):
  encrypted += number_to_character[encrypted_numeric[i : i + 3]]
-
  return encrypted
 
 
 def decrypt_message(
  message: str, alphabet: str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ.", period: int = 5
 ) -> str:
+ """
+ decrypt_message
+ ===============
+
+ Decrypts a trifid_cipher encrypted message .
+
+ PARAMETERS
+ ----------
+
+ * message: The message you want to decrypt .
+ * alphabet (optional): The characters used for the cipher.
+ * period (optional): The number of characters used in grouping when it
+ was encrypted.
+
+ >>> decrypt_message('BCDGBQY')
+ 'IAMABOY'
+
+ Decrypting with your own alphabet and period
+ >>> decrypt_message('FMJFVOISSUFTFPUFEQQC','FELIXMARDSTBCGHJKNOPQUVWYZ+',5)
+ 'AIDETOILECIELTAIDERA'
+ """
  message, alphabet, character_to_number, number_to_character = __prepare(
  message, alphabet
  )
- decrypted_numeric = []
- decrypted = ""
 
- for i in range(0, len(message) + 1, period):
+ decrypted_numeric = []
+ for i in range(0, len(message), period):
  a, b, c = __decrypt_part(message[i : i + period], character_to_number)
 
  for j in range(len(a)):
  decrypted_numeric.append(a[j] + b[j] + c[j])
 
- for each in decrypted_numeric:
- decrypted += number_to_character[each]
-
- return decrypted
+ return "".join(number_to_character[each] for each in decrypted_numeric)
 
 
 if __name__ == "__main__":
+ import doctest
+
+ doctest.testmod()
  msg = "DEFEND THE EAST WALL OF THE CASTLE."
  encrypted = encrypt_message(msg, "EPSDUCVWYM.ZLKXNBTFGORIJHAQ")
  decrypted = decrypt_message(encrypted, "EPSDUCVWYM.ZLKXNBTFGORIJHAQ")

pyproject.toml

@@ -135,5 +135,5 @@ omit = [
 sort = "Cover"
 
 [tool.codespell]
-ignore-words-list = "3rt,ans,crate,damon,fo,followings,hist,iff,kwanza,manuel,mater,secant,som,sur,tim,zar"
+ignore-words-list = "3rt,ans,crate,damon,fo,followings,hist,iff,kwanza,manuel,mater,secant,som,sur,tim,toi,zar"
 skip = "./.*,*.json,ciphers/prehistoric_men.txt,project_euler/problem_022/p022_names.txt,pyproject.toml,strings/dictionary.txt,strings/words.txt"

ciphers/trifid_cipher.py

@@ -1,15 +1,35 @@
-# https://en.wikipedia.org/wiki/Trifid_cipher
+"""
+The trifid cipher uses a table to fractionate each plaintext letter into a trigram,
+mixes the constituents of the trigrams, and then applies the table in reverse to turn
+these mixed trigrams into ciphertext letters.
+
+https://en.wikipedia.org/wiki/Trifid_cipher
+"""
+
 from __future__ import annotations
 
+# fmt: off
+TEST_CHARACTER_TO_NUMBER = {
+ "A": "111", "B": "112", "C": "113", "D": "121", "E": "122", "F": "123", "G": "131",
+ "H": "132", "I": "133", "J": "211", "K": "212", "L": "213", "M": "221", "N": "222",
+ "O": "223", "P": "231", "Q": "232", "R": "233", "S": "311", "T": "312", "U": "313",
+ "V": "321", "W": "322", "X": "323", "Y": "331", "Z": "332", "+": "333",
+}
+# fmt: off
 
-def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> str:
- one, two, three = "", "", ""
- tmp = []
+TEST_NUMBER_TO_CHARACTER = {val: key for key, val in TEST_CHARACTER_TO_NUMBER.items()}
 
- for character in message_part:
- tmp.append(character_to_number[character])
 
- for each in tmp:
+def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> str:
+ """
+ Arrange the triagram value of each letter of 'message_part' vertically and join
+ them horizontally.
+
+ >>> __encrypt_part('ASK', TEST_CHARACTER_TO_NUMBER)
+ '132111112'
+ """
+ one, two, three = "", "", ""
+ for each in (character_to_number[character] for character in message_part):
  one += each[0]
  two += each[1]
  three += each[2]
@@ -20,12 +40,16 @@ def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> st
 def __decrypt_part(
  message_part: str, character_to_number: dict[str, str]
 ) -> tuple[str, str, str]:
- tmp, this_part = "", ""
+ """
+ Convert each letter of the input string into their respective trigram values, join
+ them and split them into three equal groups of strings which are returned.
+
+ >>> __decrypt_part('ABCDE', TEST_CHARACTER_TO_NUMBER)
+ ('11111', '21131', '21122')
+ """
+ this_part = "".join(character_to_number[character] for character in message_part)
  result = []
-
- for character in message_part:
- this_part += character_to_number[character]
-
+ tmp = ""
  for digit in this_part:
  tmp += digit
  if len(tmp) == len(message_part):
@@ -38,97 +62,148 @@ def __decrypt_part(
 def __prepare(
  message: str, alphabet: str
 ) -> tuple[str, str, dict[str, str], dict[str, str]]:
+ """
+ A helper function that generates the triagrams and assigns each letter of the
+ alphabet to its corresponding triagram and stores this in a dictionary
+ ("character_to_number" and "number_to_character") after confirming if the
+ alphabet's length is 27.
+
+ >>> test = __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVwxYZ+')
+ >>> expected = ('IAMABOY','ABCDEFGHIJKLMNOPQRSTUVWXYZ+',
+ ... TEST_CHARACTER_TO_NUMBER, TEST_NUMBER_TO_CHARACTER)
+ >>> test == expected
+ True
+
+ Testing with incomplete alphabet
+ >>> __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVw')
+ Traceback (most recent call last):
+ ...
+ KeyError: 'Length of alphabet has to be 27.'
+
+ Testing with extra long alphabets
+ >>> __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVwxyzzwwtyyujjgfd')
+ Traceback (most recent call last):
+ ...
+ KeyError: 'Length of alphabet has to be 27.'
+
+ Testing with punctuations that are not in the given alphabet
+ >>> __prepare('am i a boy?','abCdeFghijkLmnopqrStuVwxYZ+')
+ Traceback (most recent call last):
+ ...
+ ValueError: Each message character has to be included in alphabet!
+
+ Testing with numbers
+ >>> __prepare(500,'abCdeFghijkLmnopqrStuVwxYZ+')
+ Traceback (most recent call last):
+ ...
+ AttributeError: 'int' object has no attribute 'replace'
+ """
  # Validate message and alphabet, set to upper and remove spaces
  alphabet = alphabet.replace(" ", "").upper()
  message = message.replace(" ", "").upper()
 
  # Check length and characters
  if len(alphabet) != 27:
  raise KeyError("Length of alphabet has to be 27.")
- for each in message:
- if each not in alphabet:
- raise ValueError("Each message character has to be included in alphabet!")
+ if any(char not in alphabet for char in message):
+ raise ValueError("Each message character has to be included in alphabet!")
 
  # Generate dictionares
- numbers = (
- "111",
- "112",
- "113",
- "121",
- "122",
- "123",
- "131",
- "132",
- "133",
- "211",
- "212",
- "213",
- "221",
- "222",
- "223",
- "231",
- "232",
- "233",
- "311",
- "312",
- "313",
- "321",
- "322",
- "323",
- "331",
- "332",
- "333",
- )
- character_to_number = {}
- number_to_character = {}
- for letter, number in zip(alphabet, numbers):
- character_to_number[letter] = number
- number_to_character[number] = letter
+ character_to_number = dict(zip(alphabet, TEST_CHARACTER_TO_NUMBER.values()))
+ number_to_character = {
+ number: letter for letter, number in character_to_number.items()
+ }
 
  return message, alphabet, character_to_number, number_to_character
 
 
 def encrypt_message(
  message: str, alphabet: str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ.", period: int = 5
 ) -> str:
+ """
+ encrypt_message
+ ===============
+
+ Encrypts a message using the trifid_cipher. Any punctuatuions that
+ would be used should be added to the alphabet.
+
+ PARAMETERS
+ ----------
+
+ * message: The message you want to encrypt.
+ * alphabet (optional): The characters to be used for the cipher .
+ * period (optional): The number of characters you want in a group whilst
+ encrypting.
+
+ >>> encrypt_message('I am a boy')
+ 'BCDGBQY'
+
+ >>> encrypt_message(' ')
+ ''
+
+ >>> encrypt_message(' aide toi le c iel ta id era ',
+ ... 'FELIXMARDSTBCGHJKNOPQUVWYZ+',5)
+ 'FMJFVOISSUFTFPUFEQQC'
+
+ """
  message, alphabet, character_to_number, number_to_character = __prepare(
  message, alphabet
  )
- encrypted, encrypted_numeric = "", ""
 
+ encrypted_numeric = ""
  for i in range(0, len(message) + 1, period):
  encrypted_numeric += __encrypt_part(
  message[i : i + period], character_to_number
  )
 
+ encrypted = ""
  for i in range(0, len(encrypted_numeric), 3):
  encrypted += number_to_character[encrypted_numeric[i : i + 3]]
-
  return encrypted
 
 
 def decrypt_message(
  message: str, alphabet: str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ.", period: int = 5
 ) -> str:
+ """
+ decrypt_message
+ ===============
+
+ Decrypts a trifid_cipher encrypted message .
+
+ PARAMETERS
+ ----------
+
+ * message: The message you want to decrypt .
+ * alphabet (optional): The characters used for the cipher.
+ * period (optional): The number of characters used in grouping when it
+ was encrypted.
+
+ >>> decrypt_message('BCDGBQY')
+ 'IAMABOY'
+
+ Decrypting with your own alphabet and period
+ >>> decrypt_message('FMJFVOISSUFTFPUFEQQC','FELIXMARDSTBCGHJKNOPQUVWYZ+',5)
+ 'AIDETOILECIELTAIDERA'
+ """
  message, alphabet, character_to_number, number_to_character = __prepare(
  message, alphabet
  )
- decrypted_numeric = []
- decrypted = ""
 
- for i in range(0, len(message) + 1, period):
+ decrypted_numeric = []
+ for i in range(0, len(message), period):
  a, b, c = __decrypt_part(message[i : i + period], character_to_number)
 
  for j in range(len(a)):
  decrypted_numeric.append(a[j] + b[j] + c[j])
 
- for each in decrypted_numeric:
- decrypted += number_to_character[each]
-
- return decrypted
+ return "".join(number_to_character[each] for each in decrypted_numeric)
 
 
 if __name__ == "__main__":
+ import doctest
+
+ doctest.testmod()
  msg = "DEFEND THE EAST WALL OF THE CASTLE."
  encrypted = encrypt_message(msg, "EPSDUCVWYM.ZLKXNBTFGORIJHAQ")
  decrypted = decrypt_message(encrypted, "EPSDUCVWYM.ZLKXNBTFGORIJHAQ")

pyproject.toml

@@ -135,5 +135,5 @@ omit = [
 sort = "Cover"
 
 [tool.codespell]
-ignore-words-list = "3rt,ans,crate,damon,fo,followings,hist,iff,kwanza,manuel,mater,secant,som,sur,tim,zar"
+ignore-words-list = "3rt,ans,crate,damon,fo,followings,hist,iff,kwanza,manuel,mater,secant,som,sur,tim,toi,zar"
 skip = "./.*,*.json,ciphers/prehistoric_men.txt,project_euler/problem_022/p022_names.txt,pyproject.toml,strings/dictionary.txt,strings/words.txt"

ciphers/trifid_cipher.py

@@ -1,15 +1,35 @@
-# https://en.wikipedia.org/wiki/Trifid_cipher
+"""
+The trifid cipher uses a table to fractionate each plaintext letter into a trigram,
+mixes the constituents of the trigrams, and then applies the table in reverse to turn
+these mixed trigrams into ciphertext letters.
+
+https://en.wikipedia.org/wiki/Trifid_cipher
+"""
+
 from __future__ import annotations
 
+# fmt: off
+TEST_CHARACTER_TO_NUMBER = {
+ "A": "111", "B": "112", "C": "113", "D": "121", "E": "122", "F": "123", "G": "131",
+ "H": "132", "I": "133", "J": "211", "K": "212", "L": "213", "M": "221", "N": "222",
+ "O": "223", "P": "231", "Q": "232", "R": "233", "S": "311", "T": "312", "U": "313",
+ "V": "321", "W": "322", "X": "323", "Y": "331", "Z": "332", "+": "333",
+}
+# fmt: off
 
-def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> str:
- one, two, three = "", "", ""
- tmp = []
+TEST_NUMBER_TO_CHARACTER = {val: key for key, val in TEST_CHARACTER_TO_NUMBER.items()}
 
- for character in message_part:
- tmp.append(character_to_number[character])
 
- for each in tmp:
+def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> str:
+ """
+ Arrange the triagram value of each letter of 'message_part' vertically and join
+ them horizontally.
+
+ >>> __encrypt_part('ASK', TEST_CHARACTER_TO_NUMBER)
+ '132111112'
+ """
+ one, two, three = "", "", ""
+ for each in (character_to_number[character] for character in message_part):
  one += each[0]
  two += each[1]
  three += each[2]
@@ -20,12 +40,16 @@ def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> st
 def __decrypt_part(
  message_part: str, character_to_number: dict[str, str]
 ) -> tuple[str, str, str]:
- tmp, this_part = "", ""
+ """
+ Convert each letter of the input string into their respective trigram values, join
+ them and split them into three equal groups of strings which are returned.
+
+ >>> __decrypt_part('ABCDE', TEST_CHARACTER_TO_NUMBER)
+ ('11111', '21131', '21122')
+ """
+ this_part = "".join(character_to_number[character] for character in message_part)
  result = []
-
- for character in message_part:
- this_part += character_to_number[character]
-
+ tmp = ""
  for digit in this_part:
  tmp += digit
  if len(tmp) == len(message_part):
@@ -38,97 +62,148 @@ def __decrypt_part(
 def __prepare(
  message: str, alphabet: str
 ) -> tuple[str, str, dict[str, str], dict[str, str]]:
+ """
+ A helper function that generates the triagrams and assigns each letter of the
+ alphabet to its corresponding triagram and stores this in a dictionary
+ ("character_to_number" and "number_to_character") after confirming if the
+ alphabet's length is 27.
+
+ >>> test = __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVwxYZ+')
+ >>> expected = ('IAMABOY','ABCDEFGHIJKLMNOPQRSTUVWXYZ+',
+ ... TEST_CHARACTER_TO_NUMBER, TEST_NUMBER_TO_CHARACTER)
+ >>> test == expected
+ True
+
+ Testing with incomplete alphabet
+ >>> __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVw')
+ Traceback (most recent call last):
+ ...
+ KeyError: 'Length of alphabet has to be 27.'
+
+ Testing with extra long alphabets
+ >>> __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVwxyzzwwtyyujjgfd')
+ Traceback (most recent call last):
+ ...
+ KeyError: 'Length of alphabet has to be 27.'
+
+ Testing with punctuations that are not in the given alphabet
+ >>> __prepare('am i a boy?','abCdeFghijkLmnopqrStuVwxYZ+')
+ Traceback (most recent call last):
+ ...
+ ValueError: Each message character has to be included in alphabet!
+
+ Testing with numbers
+ >>> __prepare(500,'abCdeFghijkLmnopqrStuVwxYZ+')
+ Traceback (most recent call last):
+ ...
+ AttributeError: 'int' object has no attribute 'replace'
+ """
  # Validate message and alphabet, set to upper and remove spaces
  alphabet = alphabet.replace(" ", "").upper()
  message = message.replace(" ", "").upper()
 
  # Check length and characters
  if len(alphabet) != 27:
  raise KeyError("Length of alphabet has to be 27.")
- for each in message:
- if each not in alphabet:
- raise ValueError("Each message character has to be included in alphabet!")
+ if any(char not in alphabet for char in message):
+ raise ValueError("Each message character has to be included in alphabet!")
 
  # Generate dictionares
- numbers = (
- "111",
- "112",
- "113",
- "121",
- "122",
- "123",
- "131",
- "132",
- "133",
- "211",
- "212",
- "213",
- "221",
- "222",
- "223",
- "231",
- "232",
- "233",
- "311",
- "312",
- "313",
- "321",
- "322",
- "323",
- "331",
- "332",
- "333",
- )
- character_to_number = {}
- number_to_character = {}
- for letter, number in zip(alphabet, numbers):
- character_to_number[letter] = number
- number_to_character[number] = letter
+ character_to_number = dict(zip(alphabet, TEST_CHARACTER_TO_NUMBER.values()))
+ number_to_character = {
+ number: letter for letter, number in character_to_number.items()
+ }
 
  return message, alphabet, character_to_number, number_to_character
 
 
 def encrypt_message(
  message: str, alphabet: str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ.", period: int = 5
 ) -> str:
+ """
+ encrypt_message
+ ===============
+
+ Encrypts a message using the trifid_cipher. Any punctuatuions that
+ would be used should be added to the alphabet.
+
+ PARAMETERS
+ ----------
+
+ * message: The message you want to encrypt.
+ * alphabet (optional): The characters to be used for the cipher .
+ * period (optional): The number of characters you want in a group whilst
+ encrypting.
+
+ >>> encrypt_message('I am a boy')
+ 'BCDGBQY'
+
+ >>> encrypt_message(' ')
+ ''
+
+ >>> encrypt_message(' aide toi le c iel ta id era ',
+ ... 'FELIXMARDSTBCGHJKNOPQUVWYZ+',5)
+ 'FMJFVOISSUFTFPUFEQQC'
+
+ """
  message, alphabet, character_to_number, number_to_character = __prepare(
  message, alphabet
  )
- encrypted, encrypted_numeric = "", ""
 
+ encrypted_numeric = ""
  for i in range(0, len(message) + 1, period):
  encrypted_numeric += __encrypt_part(
  message[i : i + period], character_to_number
  )
 
+ encrypted = ""
  for i in range(0, len(encrypted_numeric), 3):
  encrypted += number_to_character[encrypted_numeric[i : i + 3]]
-
  return encrypted
 
 
 def decrypt_message(
  message: str, alphabet: str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ.", period: int = 5
 ) -> str:
+ """
+ decrypt_message
+ ===============
+
+ Decrypts a trifid_cipher encrypted message .
+
+ PARAMETERS
+ ----------
+
+ * message: The message you want to decrypt .
+ * alphabet (optional): The characters used for the cipher.
+ * period (optional): The number of characters used in grouping when it
+ was encrypted.
+
+ >>> decrypt_message('BCDGBQY')
+ 'IAMABOY'
+
+ Decrypting with your own alphabet and period
+ >>> decrypt_message('FMJFVOISSUFTFPUFEQQC','FELIXMARDSTBCGHJKNOPQUVWYZ+',5)
+ 'AIDETOILECIELTAIDERA'
+ """
  message, alphabet, character_to_number, number_to_character = __prepare(
  message, alphabet
  )
- decrypted_numeric = []
- decrypted = ""
 
- for i in range(0, len(message) + 1, period):
+ decrypted_numeric = []
+ for i in range(0, len(message), period):
  a, b, c = __decrypt_part(message[i : i + period], character_to_number)
 
  for j in range(len(a)):
  decrypted_numeric.append(a[j] + b[j] + c[j])
 
- for each in decrypted_numeric:
- decrypted += number_to_character[each]
-
- return decrypted
+ return "".join(number_to_character[each] for each in decrypted_numeric)
 
 
 if __name__ == "__main__":
+ import doctest
+
+ doctest.testmod()
  msg = "DEFEND THE EAST WALL OF THE CASTLE."
  encrypted = encrypt_message(msg, "EPSDUCVWYM.ZLKXNBTFGORIJHAQ")
  decrypted = decrypt_message(encrypted, "EPSDUCVWYM.ZLKXNBTFGORIJHAQ")

pyproject.toml

@@ -135,5 +135,5 @@ omit = [
 sort = "Cover"
 
 [tool.codespell]
-ignore-words-list = "3rt,ans,crate,damon,fo,followings,hist,iff,kwanza,manuel,mater,secant,som,sur,tim,zar"
+ignore-words-list = "3rt,ans,crate,damon,fo,followings,hist,iff,kwanza,manuel,mater,secant,som,sur,tim,toi,zar"
 skip = "./.*,*.json,ciphers/prehistoric_men.txt,project_euler/problem_022/p022_names.txt,pyproject.toml,strings/dictionary.txt,strings/words.txt"

ciphers/trifid_cipher.py

@@ -1,15 +1,35 @@
-# https://en.wikipedia.org/wiki/Trifid_cipher
+"""
+The trifid cipher uses a table to fractionate each plaintext letter into a trigram,
+mixes the constituents of the trigrams, and then applies the table in reverse to turn
+these mixed trigrams into ciphertext letters.
+
+https://en.wikipedia.org/wiki/Trifid_cipher
+"""
+
 from __future__ import annotations
 
+# fmt: off
+TEST_CHARACTER_TO_NUMBER = {
+ "A": "111", "B": "112", "C": "113", "D": "121", "E": "122", "F": "123", "G": "131",
+ "H": "132", "I": "133", "J": "211", "K": "212", "L": "213", "M": "221", "N": "222",
+ "O": "223", "P": "231", "Q": "232", "R": "233", "S": "311", "T": "312", "U": "313",
+ "V": "321", "W": "322", "X": "323", "Y": "331", "Z": "332", "+": "333",
+}
+# fmt: off
 
-def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> str:
- one, two, three = "", "", ""
- tmp = []
+TEST_NUMBER_TO_CHARACTER = {val: key for key, val in TEST_CHARACTER_TO_NUMBER.items()}
 
- for character in message_part:
- tmp.append(character_to_number[character])
 
- for each in tmp:
+def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> str:
+ """
+ Arrange the triagram value of each letter of 'message_part' vertically and join
+ them horizontally.
+
+ >>> __encrypt_part('ASK', TEST_CHARACTER_TO_NUMBER)
+ '132111112'
+ """
+ one, two, three = "", "", ""
+ for each in (character_to_number[character] for character in message_part):
  one += each[0]
  two += each[1]
  three += each[2]
@@ -20,12 +40,16 @@ def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> st
 def __decrypt_part(
  message_part: str, character_to_number: dict[str, str]
 ) -> tuple[str, str, str]:
- tmp, this_part = "", ""
+ """
+ Convert each letter of the input string into their respective trigram values, join
+ them and split them into three equal groups of strings which are returned.
+
+ >>> __decrypt_part('ABCDE', TEST_CHARACTER_TO_NUMBER)
+ ('11111', '21131', '21122')
+ """
+ this_part = "".join(character_to_number[character] for character in message_part)
  result = []
-
- for character in message_part:
- this_part += character_to_number[character]
-
+ tmp = ""
  for digit in this_part:
  tmp += digit
  if len(tmp) == len(message_part):
@@ -38,97 +62,148 @@ def __decrypt_part(
 def __prepare(
  message: str, alphabet: str
 ) -> tuple[str, str, dict[str, str], dict[str, str]]:
+ """
+ A helper function that generates the triagrams and assigns each letter of the
+ alphabet to its corresponding triagram and stores this in a dictionary
+ ("character_to_number" and "number_to_character") after confirming if the
+ alphabet's length is 27.
+
+ >>> test = __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVwxYZ+')
+ >>> expected = ('IAMABOY','ABCDEFGHIJKLMNOPQRSTUVWXYZ+',
+ ... TEST_CHARACTER_TO_NUMBER, TEST_NUMBER_TO_CHARACTER)
+ >>> test == expected
+ True
+
+ Testing with incomplete alphabet
+ >>> __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVw')
+ Traceback (most recent call last):
+ ...
+ KeyError: 'Length of alphabet has to be 27.'
+
+ Testing with extra long alphabets
+ >>> __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVwxyzzwwtyyujjgfd')
+ Traceback (most recent call last):
+ ...
+ KeyError: 'Length of alphabet has to be 27.'
+
+ Testing with punctuations that are not in the given alphabet
+ >>> __prepare('am i a boy?','abCdeFghijkLmnopqrStuVwxYZ+')
+ Traceback (most recent call last):
+ ...
+ ValueError: Each message character has to be included in alphabet!
+
+ Testing with numbers
+ >>> __prepare(500,'abCdeFghijkLmnopqrStuVwxYZ+')
+ Traceback (most recent call last):
+ ...
+ AttributeError: 'int' object has no attribute 'replace'
+ """
  # Validate message and alphabet, set to upper and remove spaces
  alphabet = alphabet.replace(" ", "").upper()
  message = message.replace(" ", "").upper()
 
  # Check length and characters
  if len(alphabet) != 27:
  raise KeyError("Length of alphabet has to be 27.")
- for each in message:
- if each not in alphabet:
- raise ValueError("Each message character has to be included in alphabet!")
+ if any(char not in alphabet for char in message):
+ raise ValueError("Each message character has to be included in alphabet!")
 
  # Generate dictionares
- numbers = (
- "111",
- "112",
- "113",
- "121",
- "122",
- "123",
- "131",
- "132",
- "133",
- "211",
- "212",
- "213",
- "221",
- "222",
- "223",
- "231",
- "232",
- "233",
- "311",
- "312",
- "313",
- "321",
- "322",
- "323",
- "331",
- "332",
- "333",
- )
- character_to_number = {}
- number_to_character = {}
- for letter, number in zip(alphabet, numbers):
- character_to_number[letter] = number
- number_to_character[number] = letter
+ character_to_number = dict(zip(alphabet, TEST_CHARACTER_TO_NUMBER.values()))
+ number_to_character = {
+ number: letter for letter, number in character_to_number.items()
+ }
 
  return message, alphabet, character_to_number, number_to_character
 
 
 def encrypt_message(
  message: str, alphabet: str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ.", period: int = 5
 ) -> str:
+ """
+ encrypt_message
+ ===============
+
+ Encrypts a message using the trifid_cipher. Any punctuatuions that
+ would be used should be added to the alphabet.
+
+ PARAMETERS
+ ----------
+
+ * message: The message you want to encrypt.
+ * alphabet (optional): The characters to be used for the cipher .
+ * period (optional): The number of characters you want in a group whilst
+ encrypting.
+
+ >>> encrypt_message('I am a boy')
+ 'BCDGBQY'
+
+ >>> encrypt_message(' ')
+ ''
+
+ >>> encrypt_message(' aide toi le c iel ta id era ',
+ ... 'FELIXMARDSTBCGHJKNOPQUVWYZ+',5)
+ 'FMJFVOISSUFTFPUFEQQC'
+
+ """
  message, alphabet, character_to_number, number_to_character = __prepare(
  message, alphabet
  )
- encrypted, encrypted_numeric = "", ""
 
+ encrypted_numeric = ""
  for i in range(0, len(message) + 1, period):
  encrypted_numeric += __encrypt_part(
  message[i : i + period], character_to_number
  )
 
+ encrypted = ""
  for i in range(0, len(encrypted_numeric), 3):
  encrypted += number_to_character[encrypted_numeric[i : i + 3]]
-
  return encrypted
 
 
 def decrypt_message(
  message: str, alphabet: str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ.", period: int = 5
 ) -> str:
+ """
+ decrypt_message
+ ===============
+
+ Decrypts a trifid_cipher encrypted message .
+
+ PARAMETERS
+ ----------
+
+ * message: The message you want to decrypt .
+ * alphabet (optional): The characters used for the cipher.
+ * period (optional): The number of characters used in grouping when it
+ was encrypted.
+
+ >>> decrypt_message('BCDGBQY')
+ 'IAMABOY'
+
+ Decrypting with your own alphabet and period
+ >>> decrypt_message('FMJFVOISSUFTFPUFEQQC','FELIXMARDSTBCGHJKNOPQUVWYZ+',5)
+ 'AIDETOILECIELTAIDERA'
+ """
  message, alphabet, character_to_number, number_to_character = __prepare(
  message, alphabet
  )
- decrypted_numeric = []
- decrypted = ""
 
- for i in range(0, len(message) + 1, period):
+ decrypted_numeric = []
+ for i in range(0, len(message), period):
  a, b, c = __decrypt_part(message[i : i + period], character_to_number)
 
  for j in range(len(a)):
  decrypted_numeric.append(a[j] + b[j] + c[j])
 
- for each in decrypted_numeric:
- decrypted += number_to_character[each]
-
- return decrypted
+ return "".join(number_to_character[each] for each in decrypted_numeric)
 
 
 if __name__ == "__main__":
+ import doctest
+
+ doctest.testmod()
  msg = "DEFEND THE EAST WALL OF THE CASTLE."
  encrypted = encrypt_message(msg, "EPSDUCVWYM.ZLKXNBTFGORIJHAQ")
  decrypted = decrypt_message(encrypted, "EPSDUCVWYM.ZLKXNBTFGORIJHAQ")

pyproject.toml

@@ -135,5 +135,5 @@ omit = [
 sort = "Cover"
 
 [tool.codespell]
-ignore-words-list = "3rt,ans,crate,damon,fo,followings,hist,iff,kwanza,manuel,mater,secant,som,sur,tim,zar"
+ignore-words-list = "3rt,ans,crate,damon,fo,followings,hist,iff,kwanza,manuel,mater,secant,som,sur,tim,toi,zar"
 skip = "./.*,*.json,ciphers/prehistoric_men.txt,project_euler/problem_022/p022_names.txt,pyproject.toml,strings/dictionary.txt,strings/words.txt"

ciphers/trifid_cipher.py

@@ -1,15 +1,35 @@
-# https://en.wikipedia.org/wiki/Trifid_cipher
+"""
+The trifid cipher uses a table to fractionate each plaintext letter into a trigram,
+mixes the constituents of the trigrams, and then applies the table in reverse to turn
+these mixed trigrams into ciphertext letters.
+
+https://en.wikipedia.org/wiki/Trifid_cipher
+"""
+
 from __future__ import annotations
 
+# fmt: off
+TEST_CHARACTER_TO_NUMBER = {
+ "A": "111", "B": "112", "C": "113", "D": "121", "E": "122", "F": "123", "G": "131",
+ "H": "132", "I": "133", "J": "211", "K": "212", "L": "213", "M": "221", "N": "222",
+ "O": "223", "P": "231", "Q": "232", "R": "233", "S": "311", "T": "312", "U": "313",
+ "V": "321", "W": "322", "X": "323", "Y": "331", "Z": "332", "+": "333",
+}
+# fmt: off
 
-def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> str:
- one, two, three = "", "", ""
- tmp = []
+TEST_NUMBER_TO_CHARACTER = {val: key for key, val in TEST_CHARACTER_TO_NUMBER.items()}
 
- for character in message_part:
- tmp.append(character_to_number[character])
 
- for each in tmp:
+def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> str:
+ """
+ Arrange the triagram value of each letter of 'message_part' vertically and join
+ them horizontally.
+
+ >>> __encrypt_part('ASK', TEST_CHARACTER_TO_NUMBER)
+ '132111112'
+ """
+ one, two, three = "", "", ""
+ for each in (character_to_number[character] for character in message_part):
  one += each[0]
  two += each[1]
  three += each[2]
@@ -20,12 +40,16 @@ def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> st
 def __decrypt_part(
  message_part: str, character_to_number: dict[str, str]
 ) -> tuple[str, str, str]:
- tmp, this_part = "", ""
+ """
+ Convert each letter of the input string into their respective trigram values, join
+ them and split them into three equal groups of strings which are returned.
+
+ >>> __decrypt_part('ABCDE', TEST_CHARACTER_TO_NUMBER)
+ ('11111', '21131', '21122')
+ """
+ this_part = "".join(character_to_number[character] for character in message_part)
  result = []
-
- for character in message_part:
- this_part += character_to_number[character]
-
+ tmp = ""
  for digit in this_part:
  tmp += digit
  if len(tmp) == len(message_part):
@@ -38,97 +62,148 @@ def __decrypt_part(
 def __prepare(
  message: str, alphabet: str
 ) -> tuple[str, str, dict[str, str], dict[str, str]]:
+ """
+ A helper function that generates the triagrams and assigns each letter of the
+ alphabet to its corresponding triagram and stores this in a dictionary
+ ("character_to_number" and "number_to_character") after confirming if the
+ alphabet's length is 27.
+
+ >>> test = __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVwxYZ+')
+ >>> expected = ('IAMABOY','ABCDEFGHIJKLMNOPQRSTUVWXYZ+',
+ ... TEST_CHARACTER_TO_NUMBER, TEST_NUMBER_TO_CHARACTER)
+ >>> test == expected
+ True
+
+ Testing with incomplete alphabet
+ >>> __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVw')
+ Traceback (most recent call last):
+ ...
+ KeyError: 'Length of alphabet has to be 27.'
+
+ Testing with extra long alphabets
+ >>> __prepare('I aM a BOy','abCdeFghijkLmnopqrStuVwxyzzwwtyyujjgfd')
+ Traceback (most recent call last):
+ ...
+ KeyError: 'Length of alphabet has to be 27.'
+
+ Testing with punctuations that are not in the given alphabet
+ >>> __prepare('am i a boy?','abCdeFghijkLmnopqrStuVwxYZ+')
+ Traceback (most recent call last):
+ ...
+ ValueError: Each message character has to be included in alphabet!
+
+ Testing with numbers
+ >>> __prepare(500,'abCdeFghijkLmnopqrStuVwxYZ+')
+ Traceback (most recent call last):
+ ...
+ AttributeError: 'int' object has no attribute 'replace'
+ """
  # Validate message and alphabet, set to upper and remove spaces
  alphabet = alphabet.replace(" ", "").upper()
  message = message.replace(" ", "").upper()
 
  # Check length and characters
  if len(alphabet) != 27:
  raise KeyError("Length of alphabet has to be 27.")
- for each in message:
- if each not in alphabet:
- raise ValueError("Each message character has to be included in alphabet!")
+ if any(char not in alphabet for char in message):
+ raise ValueError("Each message character has to be included in alphabet!")
 
  # Generate dictionares
- numbers = (
- "111",
- "112",
- "113",
- "121",
- "122",
- "123",
- "131",
- "132",
- "133",
- "211",
- "212",
- "213",
- "221",
- "222",
- "223",
- "231",
- "232",
- "233",
- "311",
- "312",
- "313",
- "321",
- "322",
- "323",
- "331",
- "332",
- "333",
- )
- character_to_number = {}
- number_to_character = {}
- for letter, number in zip(alphabet, numbers):
- character_to_number[letter] = number
- number_to_character[number] = letter
+ character_to_number = dict(zip(alphabet, TEST_CHARACTER_TO_NUMBER.values()))
+ number_to_character = {
+ number: letter for letter, number in character_to_number.items()
+ }
 
  return message, alphabet, character_to_number, number_to_character
 
 
 def encrypt_message(
  message: str, alphabet: str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ.", period: int = 5
 ) -> str:
+ """
+ encrypt_message
+ ===============
+
+ Encrypts a message using the trifid_cipher. Any punctuatuions that
+ would be used should be added to the alphabet.
+
+ PARAMETERS
+ ----------
+
+ * message: The message you want to encrypt.
+ * alphabet (optional): The characters to be used for the cipher .
+ * period (optional): The number of characters you want in a group whilst
+ encrypting.
+
+ >>> encrypt_message('I am a boy')
+ 'BCDGBQY'
+
+ >>> encrypt_message(' ')
+ ''
+
+ >>> encrypt_message(' aide toi le c iel ta id era ',
+ ... 'FELIXMARDSTBCGHJKNOPQUVWYZ+',5)
+ 'FMJFVOISSUFTFPUFEQQC'
+
+ """
  message, alphabet, character_to_number, number_to_character = __prepare(
  message, alphabet
  )
- encrypted, encrypted_numeric = "", ""
 
+ encrypted_numeric = ""
  for i in range(0, len(message) + 1, period):
  encrypted_numeric += __encrypt_part(
  message[i : i + period], character_to_number
  )
 
+ encrypted = ""
  for i in range(0, len(encrypted_numeric), 3):
  encrypted += number_to_character[encrypted_numeric[i : i + 3]]
-
  return encrypted
 
 
 def decrypt_message(
  message: str, alphabet: str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ.", period: int = 5
 ) -> str:
+ """
+ decrypt_message
+ ===============
+
+ Decrypts a trifid_cipher encrypted message .
+
+ PARAMETERS
+ ----------
+
+ * message: The message you want to decrypt .
+ * alphabet (optional): The characters used for the cipher.
+ * period (optional): The number of characters used in grouping when it
+ was encrypted.
+
+ >>> decrypt_message('BCDGBQY')
+ 'IAMABOY'
+
+ Decrypting with your own alphabet and period
+ >>> decrypt_message('FMJFVOISSUFTFPUFEQQC','FELIXMARDSTBCGHJKNOPQUVWYZ+',5)
+ 'AIDETOILECIELTAIDERA'
+ """
  message, alphabet, character_to_number, number_to_character = __prepare(
  message, alphabet
  )
- decrypted_numeric = []
- decrypted = ""
 
- for i in range(0, len(message) + 1, period):
+ decrypted_numeric = []
+ for i in range(0, len(message), period):
  a, b, c = __decrypt_part(message[i : i + period], character_to_number)
 
  for j in range(len(a)):
  decrypted_numeric.append(a[j] + b[j] + c[j])
 
- for each in decrypted_numeric:
- decrypted += number_to_character[each]
-
- return decrypted
+ return "".join(number_to_character[each] for each in decrypted_numeric)
 
 
 if __name__ == "__main__":
+ import doctest
+
+ doctest.testmod()
  msg = "DEFEND THE EAST WALL OF THE CASTLE."
  encrypted = encrypt_message(msg, "EPSDUCVWYM.ZLKXNBTFGORIJHAQ")
  decrypted = decrypt_message(encrypted, "EPSDUCVWYM.ZLKXNBTFGORIJHAQ")

pyproject.toml

@@ -135,5 +135,5 @@ omit = [
 sort = "Cover"
 
 [tool.codespell]
-ignore-words-list = "3rt,ans,crate,damon,fo,followings,hist,iff,kwanza,manuel,mater,secant,som,sur,tim,zar"
+ignore-words-list = "3rt,ans,crate,damon,fo,followings,hist,iff,kwanza,manuel,mater,secant,som,sur,tim,toi,zar"
 skip = "./.*,*.json,ciphers/prehistoric_men.txt,project_euler/problem_022/p022_names.txt,pyproject.toml,strings/dictionary.txt,strings/words.txt"