




'''simple docstring'''



from __future__ import annotations

from collections.abc import Iterator
from typing import Any





class        UpperCAmelCase_  :





    """simple docstring"""






    def __init__(							self      ,					SCREAMING_SNAKE_CASE_     )    ->					None:
         __lowerCamelCase       :     Any        =		data
         __lowerCamelCase       :     Node | None        =		None







    def __str__(							self     )    ->					str:
         return f'{self.data}'







class        UpperCAmelCase_  :





    """simple docstring"""






    def __init__(							self     )    ->					None:
         __lowerCamelCase       :     Node | None        =		None
         __lowerCamelCase       :     Node | None        =		None







    def __iter__(							self     )    ->					Iterator[Any]:
         __lowerCamelCase       :     Any        =		self.front
         while node:
              yield node.data
              __lowerCamelCase       :     Any        =		node.next







    def __len__(							self     )    ->					int:
         return len(tuple(iter(self     )     )     )







    def __str__(							self     )    ->					str:
         return " <- ".join(str(_snake_case     ) for item in self     )







    def 				lowercase_    (							self     )    ->					bool:
         return len(self     ) == 0







    def 				lowercase_    (							self      ,					SCREAMING_SNAKE_CASE_     )    ->					None:
         __lowerCamelCase       :     Dict        =		Node(_snake_case     )
         if self.is_empty():
              __lowerCamelCase       :     int        =		node
         else:
              assert isinstance(self.rear      ,					_snake_case     )
              __lowerCamelCase       :     str        =		node
              __lowerCamelCase       :     Union[str, Any]        =		node







    def 				lowercase_    (							self     )    ->					Any:
         if self.is_empty():
              raise IndexError('dequeue from empty queue'     )
         assert isinstance(self.front      ,					_snake_case     )
         __lowerCamelCase       :     Union[str, Any]        =		self.front
         __lowerCamelCase       :     str        =		self.front.next
         if self.front is None:
              __lowerCamelCase       :     Any        =		None
         return node.data







    def 				lowercase_    (							self     )    ->					None:
         __lowerCamelCase       :     List[Any]        =		None


if __name__ == "__main__":
      from doctest import testmod

      testmod()










'''simple docstring'''



from typing import Literal

A__		: Tuple												=  """ABCDEFGHIJKLMNOPQRSTUVWXYZ"""



def       UpperCAmelCase__ (     UpperCAmelCase_   :    str				,   UpperCAmelCase_   :    str				,   UpperCAmelCase_   :    Literal["encrypt", "decrypt"]							)					->		str:
     __lowerCamelCase       :     Dict        =		LETTERS if mode == 'decrypt' else key
     __lowerCamelCase       :     Tuple        =		key if mode == 'decrypt' else LETTERS
     __lowerCamelCase       :     Optional[int]        =		''
     # loop through each symbol in the message
     for symbol in message:
          if symbol.upper() in chars_a:
               # encrypt/decrypt the symbol
               __lowerCamelCase       :     Optional[int]        =		chars_a.find(symbol.upper()							)
               if symbol.isupper():
                    translated += chars_b[sym_index].upper()
               else:
                    translated += chars_b[sym_index].lower()
          else:
               # symbol is not in LETTERS, just add it
               translated += symbol
     return translated



def       UpperCAmelCase__ (     UpperCAmelCase_   :    str				,   UpperCAmelCase_   :    str							)					->		str:
     return translate_message(UpperCAmelCase_				,   UpperCAmelCase_				,   'encrypt'							)



def       UpperCAmelCase__ (     UpperCAmelCase_   :    str				,   UpperCAmelCase_   :    str							)					->		str:
     return translate_message(UpperCAmelCase_				,   UpperCAmelCase_				,   'decrypt'							)



def       UpperCAmelCase__ (     )					->		None:
     __lowerCamelCase       :     Dict        =		'Hello World'
     __lowerCamelCase       :     str        =		'QWERTYUIOPASDFGHJKLZXCVBNM'
     __lowerCamelCase       :     Any        =		'decrypt'  # set to 'encrypt' or 'decrypt'

     if mode == "encrypt":
          __lowerCamelCase       :     Optional[int]        =		encrypt_message(UpperCAmelCase_				,   UpperCAmelCase_							)
     elif mode == "decrypt":
          __lowerCamelCase       :     List[str]        =		decrypt_message(UpperCAmelCase_				,   UpperCAmelCase_							)
     print(F'Using the key {key}, the {mode}ed message is: {translated}'							)


if __name__ == "__main__":
      import doctest

      doctest.testmod()
      main()






