code for decryption of caesar cipher python code example

Example 1: python caesar cipher

def caesar_encrypt():
    word = input('Enter the plain text: ')
    c = ''
    for i in word:
        if (i == ' '):
            c += ' '
        else:
            c += (chr(ord(i) + 3))
    return c

def caesar_decrypt():
    word = input('Enter the cipher text: ')
    c = ''
    for i in word:
        if (i == ' '):
            c += ' '
        else:
            c += (chr(ord(i) - 3))
    return c
  
plain = 'hello'
cipher = caesar_encrypt(plain)
decipher = caesar_decrypt(cipher)

Example 2: python caesar cipher

plaintext = input("Please enter your plaintext: ")
shift = input("Please enter your key: ")
alphabet = "abcdefghijklmnopqrstuvwxyz"
ciphertext = ""

# shift value can only be an integer
while isinstance(int(shift), int) == False:
  # asking the user to reenter the shift value
  shift = input("Please enter your key (integers only!): ")

shift = int(shift)
  
new_ind = 0 # this value will be changed later
for i in plaintext:
  if i.lower() in alphabet:
    new_ind = alphabet.index(i) + shift
    ciphertext += alphabet[new_ind % 26]
  else:
    ciphertext += i    
print("The ciphertext is: " + ciphertext)