Removed double implementation of vigenere_cipher.py. Fixes TheAlgorit…

…hms#8098

ciphers/vigenere_cipher.py

@@ -1,65 +1,82 @@
-LETTERS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+"""
+Author: Mohit Radadiya
+"""
 
+from string import ascii_uppercase
 
-def main() -> None:
-    message = input("Enter message: ")
-    key = input("Enter key [alphanumeric]: ")
-    mode = input("Encrypt/Decrypt [e/d]: ")
-
-    if mode.lower().startswith("e"):
-        mode = "encrypt"
-        translated = encrypt_message(key, message)
-    elif mode.lower().startswith("d"):
-        mode = "decrypt"
-        translated = decrypt_message(key, message)
+dict1 = {char: i for i, char in enumerate(ascii_uppercase)}
+dict2 = dict(enumerate(ascii_uppercase))
 
-    print(f"\n{mode.title()}ed message:")
-    print(translated)
 
-
-def encrypt_message(key: str, message: str) -> str:
+# This function generates the key in
+# a cyclic manner until it's length isn't
+# equal to the length of original text
+def generate_key(message: str, key: str) -> str:
     """
-    >>> encrypt_message('HDarji', 'This is Harshil Darji from Dharmaj.')
-    'Akij ra Odrjqqs Gaisq muod Mphumrs.'
+    >>> generate_key("THE GERMAN ATTACK","SECRET")
+    'SECRETSECRETSECRE'
     """
-    return translate_message(key, message, "encrypt")
-
-
-def decrypt_message(key: str, message: str) -> str:
+    x = len(message)
+    i = 0
+    while True:
+        if x == i:
+            i = 0
+        if len(key) == len(message):
+            break
+        key += key[i]
+        i += 1
+    return key
+
+
+# This function returns the encrypted text
+# generated with the help of the key
+def cipher_text(message: str, key_new: str) -> str:
     """
-    >>> decrypt_message('HDarji', 'Akij ra Odrjqqs Gaisq muod Mphumrs.')
-    'This is Harshil Darji from Dharmaj.'
+    >>> cipher_text("THE GERMAN ATTACK","SECRETSECRETSECRE")
+    'BDC PAYUWL JPAIYI'
     """
-    return translate_message(key, message, "decrypt")
-
-
-def translate_message(key: str, message: str, mode: str) -> str:
-    translated = []
-    key_index = 0
-    key = key.upper()
+    cipher_text = ""
+    i = 0
+    for letter in message:
+        if letter == " ":
+            cipher_text += " "
+        else:
+            x = (dict1[letter] - dict1[key_new[i]]) % 26
+            i += 1
+            cipher_text += dict2[x]
+    return cipher_text
 
-    for symbol in message:
-        num = LETTERS.find(symbol.upper())
-        if num != -1:
-            if mode == "encrypt":
-                num += LETTERS.find(key[key_index])
-            elif mode == "decrypt":
-                num -= LETTERS.find(key[key_index])
 
-            num %= len(LETTERS)
+# This function decrypts the encrypted text
+# and returns the original text
+def original_text(cipher_text: str, key_new: str) -> str:
+    """
+    >>> original_text("BDC PAYUWL JPAIYI","SECRETSECRETSECRE")
+    'THE GERMAN ATTACK'
+    """
+    or_txt = ""
+    i = 0
+    for letter in cipher_text:
+        if letter == " ":
+            or_txt += " "
+        else:
+            x = (dict1[letter] + dict1[key_new[i]] + 26) % 26
+            i += 1
+            or_txt += dict2[x]
+    return or_txt
 
-            if symbol.isupper():
-                translated.append(LETTERS[num])
-            elif symbol.islower():
-                translated.append(LETTERS[num].lower())
 
-            key_index += 1
-            if key_index == len(key):
-                key_index = 0
-        else:
-            translated.append(symbol)
-    return "".join(translated)
+def main() -> None:
+    message = "THE GERMAN ATTACK"
+    key = "SECRET"
+    key_new = generate_key(message, key)
+    s = cipher_text(message, key_new)
+    print(f"Encrypted Text = {s}")
+    print(f"Original Text = {original_text(s, key_new)}")
 
 
 if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()
     main()