Fix typo in filename: ciphers/trifid_cipher.py (#10516)

* Update and rename trafid_cipher.py to trifid_cipher.py

* updating DIRECTORY.md

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Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>

ciphers/trifid_cipher.py

@@ -0,0 +1,135 @@
+# https://en.wikipedia.org/wiki/Trifid_cipher
+from __future__ import annotations
+
+
+def __encrypt_part(message_part: str, character_to_number: dict[str, str]) -> str:
+    one, two, three = "", "", ""
+    tmp = []
+
+    for character in message_part:
+        tmp.append(character_to_number[character])
+
+    for each in tmp:
+        one += each[0]
+        two += each[1]
+        three += each[2]
+
+    return one + two + three
+
+
+def __decrypt_part(
+    message_part: str, character_to_number: dict[str, str]
+) -> tuple[str, str, str]:
+    tmp, this_part = "", ""
+    result = []
+
+    for character in message_part:
+        this_part += character_to_number[character]
+
+    for digit in this_part:
+        tmp += digit
+        if len(tmp) == len(message_part):
+            result.append(tmp)
+            tmp = ""
+
+    return result[0], result[1], result[2]
+
+
+def __prepare(
+    message: str, alphabet: str
+) -> tuple[str, str, dict[str, str], dict[str, str]]:
+    # 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!")
+
+    # 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
+
+    return message, alphabet, character_to_number, number_to_character
+
+
+def encrypt_message(
+    message: str, alphabet: str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ.", period: int = 5
+) -> str:
+    message, alphabet, character_to_number, number_to_character = __prepare(
+        message, alphabet
+    )
+    encrypted, encrypted_numeric = "", ""
+
+    for i in range(0, len(message) + 1, period):
+        encrypted_numeric += __encrypt_part(
+            message[i : i + period], character_to_number
+        )
+
+    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:
+    message, alphabet, character_to_number, number_to_character = __prepare(
+        message, alphabet
+    )
+    decrypted_numeric = []
+    decrypted = ""
+
+    for i in range(0, len(message) + 1, 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
+
+
+if __name__ == "__main__":
+    msg = "DEFEND THE EAST WALL OF THE CASTLE."
+    encrypted = encrypt_message(msg, "EPSDUCVWYM.ZLKXNBTFGORIJHAQ")
+    decrypted = decrypt_message(encrypted, "EPSDUCVWYM.ZLKXNBTFGORIJHAQ")
+    print(f"Encrypted: {encrypted}\nDecrypted: {decrypted}")