#9: Implementing Stromchiffre

- Also various bug fixes and improvements

utils/AlphabetUtils.py

@@ -1,8 +1,10 @@
+import decimal
+
 LETTERS = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V',
 		   'W', 'X', 'Y', 'Z']
 
 
-def is_letter_of_alphabet(letter: str):
+def is_letter_of_alphabet(letter: str) -> bool:
 	"""
 	Checks if the given letter is a valid letter of the alphabet
 	:param letter: The letter to check
@@ -11,7 +13,7 @@ def is_letter_of_alphabet(letter: str):
 	return letter.upper() in LETTERS
 
 
-def get_letter_at_index(idx: int, capital: bool = False):
+def get_letter_at_index(idx: int, capital: bool = False) -> str:
 	"""
 	Returns the letter at the given index
 	:param idx: The index of the letter to return
@@ -24,7 +26,7 @@ def get_letter_at_index(idx: int, capital: bool = False):
 	return LETTERS[idx] if capital else LETTERS[idx].lower()
 
 
-def get_index_of_letter(letter: str):
+def get_index_of_letter(letter: str) -> int:
 	"""
 	Returns the index of the given letter
 	:param letter: The letter to return the index of
@@ -34,3 +36,16 @@ def get_index_of_letter(letter: str):
 		raise AttributeError
 
 	return LETTERS.index(letter.upper())
+
+def get_binary_index_of_letter(letter: str) -> str:
+	"""
+	Returns the binary representation of the letter index
+	:param letter: The letter to return the index for
+	:return: The binary representation of the letter index
+	"""
+	char_index = get_index_of_letter(letter)
+	return bin(char_index)[2:].zfill(6)
+
+def get_letter_at_binary_index(index: str) -> str:
+	decimal_index = int(index, 2)
+	return get_letter_at_index(decimal_index)