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Add docstrings and doctests and fix a bug ciphers/trifid_cipher.py (T…
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* Added docstrings,doctests and fixed a bug

* Added docstrings,doctests and fixed a bug

* Added docstrings,doctests and fixed a bug

* Added docstrings and doctests with a bug fix

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* Added docstrings and doctests with a bug fix

* Update ciphers/trifid_cipher.py

Co-authored-by: Christian Clauss <[email protected]>

* Update ciphers/trifid_cipher.py

Co-authored-by: Christian Clauss <[email protected]>

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Docstrings edit

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* Update trifid_cipher.py

* Update pyproject.toml

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Christian Clauss <[email protected]>
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191 changes: 133 additions & 58 deletions ciphers/trifid_cipher.py
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Original file line number Diff line number Diff line change
@@ -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]
Expand All @@ -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):
Expand All @@ -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")
Expand Down
2 changes: 1 addition & 1 deletion pyproject.toml
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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"

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