### ORD & CHR HOMEWORK REFACTORED

# imports libraries for use (json to read a json file and stats to find the modal value of a list)

import json

from statistics import StatisticsError, mode

def menu():

menuSelect = input("1: Encrypt\n2: Decrypt\n3: Exit\n") # asks the user for an option

if menuSelect == "1": # runs the subroutines to encrypt a message

mP = message()

encrypt(mP)

elif menuSelect == "2": # Runs the subroutines to decrypt a message

mP = message()

formedList = decrypt(mP)

jsonCheck(formedList)

elif menuSelect == "3": # exits the program if the uses selects "3"

print("Goodbye!")

exit()

else: # Run the Menu if an option other than 1, 2 or 3 is selected

menu()

# Gets the user's message and splits each word into an element of a list

def message():

print("#-"*25)

message = input("Input the message: ")

messageParts = message.split(" ")

return messageParts

## Defines a subroutine to Encrypt messages

def encrypt(messageParts):

# Requests a number of spaces to displace the letters

key = int(input("What would you like to encrypt by: "))

# Encrypts each letter by the key and returns the result

for word in messageParts:

for j in range(len(word)):

letter = word[j]

value = ord(letter)

if not letter.isalpha():

print(letter, end="")

else:

if letter.isupper():

if value + key > 90:

chrCode = value + key - 90

newChr = 64 + chrCode

else:

newChr = value + key

elif letter.islower():

if value + key > 122:

chrCode = value + key - 122

newChr = 96 + chrCode

else:

newChr = value + key

print(chr(newChr), end = "")

print(end=" ")

print()

print("#-"*25)

menu()

## Defines a subroutine for decryption

def decrypt(messageParts):

# Requests whether the cipher Key is known

decision = input("\nDo you know what the caeser key is? Y or N\n").upper()

decryptList = []

# Decodes if the cipher key is known

if decision == "Y":

key = int(input("What to decrypt by: "))

# decodes according to the key given

for word in messageParts:

for j in range(len(word)):

letter = word[j]

value = ord(letter)

if not letter.isalpha():

print(letter, end="")

else:

if letter.isupper():

if value - key < 65:

chrCode = 65 - value + key

newChr = 91 - chrCode

else:

newChr = value - key

elif letter.islower():

if value - key < 97:

chrCode = 97 - value + key

newChr = 123 - chrCode

else:

newChr = value - key

print(chr(newChr), end = "")

print(end=" ")

# Reruns Menu

print()

print("#-"*25)

menu()

# If the cipher key is unknown, run this:

elif decision == "N":

# Decodes each letter and forms it in 3d lists

for word in messageParts:

sepWord = []

for key in range(1,27):

sepLetter = []

for j in range(len(word)):

letter = word[j]

value = ord(letter)

if not letter.isalpha():

wordValue = letter

else:

if letter.isupper():

if value - key < 65:

chrCode = 65 - value + key

newChr = 91 - chrCode

else:

newChr = value - key

elif letter.islower():

if value - key < 97:

chrCode = 97 - value + key

newChr = 123 - chrCode

else:

newChr = value - key

wordValue = chr(newChr)

sepLetter.append(wordValue)

sepWord.append(sepLetter)

decryptList.append(sepWord)

formedList = []

# Recompiles the words from letters and separates them by which word is belongs to in the message and the combination it could be

for wordSet in decryptList:

formedWordSet = []

for word in wordSet:

formedWord = "".join(word)

formedWordSet.append(formedWord)

formedList.append(formedWordSet)

print("#-"*25)

print("Possible Sentences:")

# Returns the recomposed sentences from each possibility

for check in range(26):

for i in range(len(messageParts)):

print(formedList[i][check], end=" ")

print()

# allows for use of the decrypted words in other subroutines

return formedList

## Defines the subroutine to check against the dictionary

def jsonCheck(fL):

indexList = []

# Loads the dictionary for use

with open("wordlist.json", "r") as f:

data = json.load(f)

# Find out the indexes of words from the sentence which exist in the dictionary

for set in fL:

for word in set:

if word.isalpha():

if word.lower() in data:

indexList.append(set.index(word))

try:

# finds out which indexes are words in the english dictionary

modalIndex = mode(indexList)

print("#-"*25)

print("Most Likely Sentence is:")

# prints the most correct sentence

for i in range(len(fL)):

print(fL[i][modalIndex], end=" ")

except StatisticsError:

print("No Option can be found as a suitable sentence from the english dictionary")

## Runs the menu Function to start the program

menu()