Question

I was given an assignment to write three sections of Code.

1. Look up password

2. Decrypt a password.

3. What website is this password for?

Here's the base code:

import csv
import sys

#The password list - We start with it populated for testing purposes
passwords = [["yahoo","XqffoZeo"],["google","CoIushujSetu"]]


#The password file name to store the passwords to
passwordFileName = "samplePasswordFile"

#The encryption key for the caesar cypher
encryptionKey=16

#Caesar Cypher Encryption
def passwordEncrypt (unencryptedMessage, key):

    #We will start with an empty string as our encryptedMessage
    encryptedMessage = ''

    #For each symbol in the unencryptedMessage we will add an encrypted symbol into the encryptedMessage
    for symbol in unencryptedMessage:
        if symbol.isalpha():
            num = ord(symbol)
            num += key

            if symbol.isupper():
                if num > ord('Z'):
                    num -= 26
                elif num < ord('A'):
                    num += 26
            elif symbol.islower():
                if num > ord('z'):
                    num -= 26
                elif num < ord('a'):
                    num += 26

            encryptedMessage += chr(num)
        else:
            encryptedMessage += symbol

    return encryptedMessage

def loadPasswordFile(fileName):

    with open(fileName, newline='') as csvfile:
        passwordreader = csv.reader(csvfile)
        passwordList = list(passwordreader)

    return passwordList

def savePasswordFile(passwordList, fileName):

    with open(fileName, 'w+', newline='') as csvfile:
        passwordwriter = csv.writer(csvfile)
        passwordwriter.writerows(passwordList)



while True:
    print("What would you like to do:")
    print(" 1. Open password file")
    print(" 2. Lookup a password")
    print(" 3. Add a password")
    print(" 4. Save password file")
    print(" 5. Print the encrypted password list (for testing)")
    print(" 6. Quit program")
    print("Please enter a number (1-4)")
    choice = input()

    if(choice == '1'): #Load the password list from a file
        passwords = loadPasswordFile(passwordFileName)

    if(choice == '2'): #Lookup at password
        print("Which website do you want to lookup the password for?")
        for keyvalue in passwords:
            print(keyvalue[0])
        passwordToLookup = input()

        ####### YOUR CODE HERE ######
        #You will need to find the password that matches the website
        #You will then need to decrypt the password

        #
        #1. Create a loop that goes through each item in the password list
        #  You can consult the reading on lists in Week 5 for ways to loop through a list
        #
        #2. Check if the name is found.  To index a list of lists you use 2 square backet sets
        #   So passwords[0][1] would mean for the first item in the list get it's 2nd item (remember, lists start at 0)
        #   So this would be 'XqffoZeo' in the password list given what is predefined at the top of the page.
        #   If you created a loop using the syntax described in step 1, then i is your 'iterator' in the list so you
        #   will want to use i in your first set of brackets.
        #
        #3. If the name is found then decrypt it.  Decrypting is that exact reverse operation from encrypting.  Take a look at the
        # caesar cypher lecture as a reference.  You do not need to write your own decryption function, you can reuse passwordEncrypt
        #
        #  Write the above one step at a time.  By this I mean, write step 1...  but in your loop print out every item in the list
        #  for testing purposes.  Then write step 2, and print out the password but not decrypted.  Then write step 3.  This way
        #  you can test easily along the way.
        #


        ####### YOUR CODE HERE ######


    if(choice == '3'):
        print("What website is this password for?")
        website = input()
        print("What is the password?")
        unencryptedPassword = input()

        ####### YOUR CODE HERE ######
        #You will need to encrypt the password and store it in the list of passwords

        #The encryption function is already written for you
        #Step 1: You can say encryptedPassword = passwordEncrypt(unencryptedPassword,encryptionKey)]
        #the encryptionKey variable is defined already as 16, don't change this
        #Step 2: create a list of size 2, first item the website name and the second item the password.
        #Step 3: append the list from Step 2 to the password list


        ####### YOUR CODE HERE ######

    if(choice == '4'): #Save the passwords to a file
            savePasswordFile(passwords,passwordFileName)


    if(choice == '5'): #print out the password list
        for keyvalue in passwords:
            print(', '.join(keyvalue))

    if(choice == '6'):  #quit our program
        sys.exit()

    print()
    print()

Answer 1

import csv
import sys

#The password list - We start with it populated for testing purposes
passwords = [["yahoo","XqffoZeo"],["google","CoIushujSetu"]]

#The password file name to store the passwords to
passwordFileName = "samplePasswordFile"

#The encryption key for the caesar cypher
encryptionKey=16

#Caesar Cypher Encryption
def passwordEncrypt (unencryptedMessage, key):

#We will start with an empty string as our encryptedMessage
encryptedMessage = ''

#For each symbol in the unencryptedMessage we will add an encrypted symbol into the encryptedMessage
for symbol in unencryptedMessage:
if symbol.isalpha():
num = ord(symbol)
num += key

if symbol.isupper():
if num > ord('Z'):
num -= 26
elif num < ord('A'):
num += 26
elif symbol.islower():
if num > ord('z'):
num -= 26
elif num < ord('a'):
num += 26

encryptedMessage += chr(num)
else:
encryptedMessage += symbol

return encryptedMessage

def loadPasswordFile(fileName):

with open(fileName, newline='') as csvfile:
passwordreader = csv.reader(csvfile)
passwordList = list(passwordreader)

return passwordList

def savePasswordFile(passwordList, fileName):

with open(fileName, 'w+', newline='') as csvfile:
passwordwriter = csv.writer(csvfile)
passwordwriter.writerows(passwordList)

while True:
print("What would you like to do:")
print(" 1. Open password file")
print(" 2. Lookup a password")
print(" 3. Add a password")
print(" 4. Save password file")
print(" 5. Print the encrypted password list (for testing)")
print(" 6. Quit program")
print("Please enter a number (1-4)")
choice = input()

if(choice == '1'): #Load the password list from a file
passwords = loadPasswordFile(passwordFileName)

if(choice == '2'): #Lookup at password
print("Which website do you want to lookup the password for?")
for keyvalue in passwords:
print(keyvalue[0])
passwordToLookup = input()

for i in passwords:# loop in passwords list
if i[0]==passwordToLookup:# if website name matches then password found
print("Password found: "+i[1])
break
s=26-encryptionKey;# decrypting password using passwordEncrypt function by changing the encryptionKey
decryptedPassword=passwordEncrypt(i[1],s)
print("Decrypted password: "+decryptedPassword)

if(choice == '3'):
print("What website is this password for?")
website = input()
print("What is the password?")
unencryptedPassword = input()
  
encryptedPassword = passwordEncrypt(unencryptedPassword,encryptionKey)
l=[]
l.append(website)# add website name to list
l.append(encryptedPassword)# add password to list
passwords.append(l)# then append list to passwords list

if(choice == '4'): #Save the passwords to a file
savePasswordFile(passwords,passwordFileName)

if(choice == '5'): #print out the password list
for keyvalue in passwords:
print(', '.join(keyvalue))

if(choice == '6'): #quit our program
sys.exit()

print()
print()