Added caesar_cipher.py an implementation with pt-br character set

This program allows the user to either encrypt a message using the
default shift value of 3 or by a custom shift value provided

Caesar Cipher/caesar_cipher.py

@@ -0,0 +1,68 @@
+def letter_shift(letter: str, shift: int) -> str:
+ """Function that shifts a given letter by a certain
+ shift that is also given, then returns the shifted 
+ letter from the brazilian portuguese character set
+
+ Args:
+ letter (str): letter to be encrypted
+ shift (int): shift from the character set
+
+ Returns:
+ str: letter that was shifted
+ """
+ # Caesar cipher implemented over brazilian portuguese character set
+ alphabet = 'abcdefghijklmnopqrstuvwyzàáãâéêóôõíúçABCDEFGHIJKLMNOPQRSTUVWYZÀÁÃÂÉÊÓÕÍÚÇ'
+ index_shifted = alphabet.find(letter) + shift
+
+ if index_shifted > len(alphabet) - 1:
+ index_shifted = index_shifted % len(alphabet)
+
+ letter_shifted = alphabet[index_shifted] 
+ return letter_shifted
+
+
+def caesar_cypher(str_user : str, shift: int = 3) -> str: 
+ """Function that shifts a string by a certain
+ shift that is also given, then returns the shifted 
+ string from the brazilian portuguese character set
+
+ Args:
+ letter (str): letter to be encrypted
+ shift (int): shift from the character set
+
+ Returns:
+ str: letter that was shifted
+ """ 
+ converted_str = ''
+ for letter in str_user:
+ if letter == ' ':
+ converted_str+= ' '
+ pass
+ else:
+ converted_str+=letter_shift(letter, shift)
+ return converted_str 
+
+def run() -> None:
+ """Run function, provides a menu to the user to either encrypt a message with the default shift or
+ gives the option of encrypting the message with a custom shift, this application of the caesar cypher
+ utilizes the brazilian portuguese character set.
+ """
+ print("Menu - Perfect Numbers Program \nTo Encrypt a message with the default shift - press 0\nTo Encrypt a message with a custom shift - press 1")
+ user_choice = int(input())
+ if user_choice == 0:
+ user_input = input("Please provide the message that will be cyphered: ")
+ cyphered_msg = caesar_cypher(user_input)
+ print(f'Your message cyphered by the caeser cypher is: {cyphered_msg}')
+ elif user_choice == 1:
+ user_input = input("Please provide the message that will be cyphered: ")
+ user_shift = int(input("Please provide the shift for cypher: "))
+ cyphered_msg = caesar_cypher(user_input, user_shift)
+ print(f'Your message cyphered by the caeser cypher is: {cyphered_msg}')
+ else:
+ print("Please select a valid option") 
+ run() 
+
+
+if __name__ == "__main__":
+ run()
+